The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this wo...The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.展开更多
Turkey is a country producing various kinds of cheese. Tomas cheese is a kind of cheese that is still traditionally produced, and it is not widely-known. In this study, the characteristic properties of Tomas cheese, a...Turkey is a country producing various kinds of cheese. Tomas cheese is a kind of cheese that is still traditionally produced, and it is not widely-known. In this study, the characteristic properties of Tomas cheese, a local product that is extensively consumed in the city of Tunceli and its environs, have been examined. For this purpose, samples from cheese varieties currently on sale in the cities of Tunceli and Elazl~ have been taken, and some of their physico-chemical and microbiological properties have been determined. The results of physico-chemical analysis showed that the average moisture rate of the samples was 53.24%, average ash rate 4.24%, average dry matter 46.76%, average acidity rate in terms of lactic acid 1.08%, average salt rate 2.93%, average fat rate 17.66%, average fat-free dry matter rate 25.56% and average pH value 4.67. The microbiological analysis data showed that the average values for the total aerobic mesophyll bacteria (TAMB) was 7 loglo kob/g, 2.3 logl0 kob/g for coliform, 4.6 logl0 kob/g for yeast, 5.5 logl0 kob/g for mold, 6.8 log10 kob/g for Lactococcus spp., and 6.1 log10 kob/g for Lactobacillus spp.. The results show the high variation among samples, proving that there has not been a standard production procedure. It has been established that the hygienic condition of the product changes according to the production process, and the probability for cross contamination is high. A large number of studies need to be carded out for this kind of traditional food items, due to lack of enough literature data in this paper.展开更多
A limited number of studies have been conducted on the effects of ozone use on cereal and its components. Starch, an important natural macromolecule, is an essential component of cereals. In present study, the effects...A limited number of studies have been conducted on the effects of ozone use on cereal and its components. Starch, an important natural macromolecule, is an essential component of cereals. In present study, the effects of ozone on the structure, physico-chemical and microbiological properties of wheat, corn, potato and rice starches were investigated. Wheat starch, corn starch, potato starch and rice starch water mixtures were prepared in the ratio of 1:9 (dry sample to water ratio) and treated with ozone at a rate of 60 g/h for 1 hour, while unozonated samples were used as controls. Light microscopy represented that the structures of corn and potato starch samples were affected by 1 hr ozonation rather than the structures of wheat and rice starch samples. Colour of ozone-oxidized wheat, corn and potato starch samples could meet the consumer preference due to the higher lightness, higher whiteness and lower chroma value. However, high chroma, high yellownes and low whiteness values of ozonated rice starch is not adequate for consumer desire. Microbiological analysis showed that 1 hr ozonation reduced the total bacteria and mould/yeast counts significantly for all wheat, corn, potato and rice starch samples (P 〈 0.05) due to most probably the reduced pH of samples. Ozonation can be an alternative modification technique, but further research is needed to understand the certain benefits and limitations of ozone applications on starch oxidation for human safety and health.展开更多
Abstract Forests have been expanding over typical savanna sites for the past 3000 years in the Neotropics. Such invasion can produce a series of environmental modifications on typical savanna; however, it remains uncl...Abstract Forests have been expanding over typical savanna sites for the past 3000 years in the Neotropics. Such invasion can produce a series of environmental modifications on typical savanna; however, it remains unclear how modifications in soil properties, caused by the encroachment of woody species, facilitate the expansion of forest ecosystems under dystrophic conditions. Here we examined chemical and microbiological changes associ- ated with tree encroachment in oxisols of a Neotropical Savanna at Assis Ecological Station, Southeastern Brazil. We predicted that tree encroachment caused by typical forest species would cause significant changes in the chemical and microbiological properties of savanna soils. Soils were sampled at Assis Ecological Station, from savanna sites differing in tree encroachment (typical, dense and forested savanna) caused by decades of fire exclusion. We analysed vegetation leaf area index and leaf litter volume deposited in the studied plots and chemical (pH,organic matter, P, K, Ca, Mg, A1, NO3-, NH4+) and microbiological (microbial C biomass and dehydrogenase activity) properties of soils under distinct encroachment conditions. Most soil chemical properties did not change along the tree encroachment gradient; however, total P, soil organic matter, soil microbial C and dehydrogenase activity increased from typical savanna to forested savanna. The changes in soil organic matter and dehydrogenase activity were correlated with the values of leaf area index and litter volume along the encroachment gradient. Our results demonstrate that forest species can increase carbon and phosphorus supplies in tropical savanna soils.展开更多
The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of it...The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and optimization.Thirteen types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial environment.Mechanical,thermal and optical,and radiation-shielding properties are considered.The influencing factors and optimization methods for these properties are analyzed.From the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction materials.Correspondingly,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.展开更多
The study was conducted to </span><span style="font-family:""><span style="font-family:Verdana;">investigate </span><span><span style="font-family:Verdana...The study was conducted to </span><span style="font-family:""><span style="font-family:Verdana;">investigate </span><span><span style="font-family:Verdana;">the physicochemical properties and microbial quality of <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> produced in the Borana zone</span></span><span style="font-family:Verdana;">. </span><span><span style="font-family:Verdana;">A total number of 35 <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> samples, 30 traditionally made plus 5 laboratories made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>,</span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">were analyzed for their physicochemical properties and microbiological quality</span><span style="font-family:""><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The overall average (±SD) values for pH, titratable acidity, total protein, fat, total solids, and ash were </span><span style="font-family:Verdana;">3.59</span></span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;"> ±</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.04</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">2.86</span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.18%</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> 7.26</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.41%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">9.85</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.73</span><span style="font-family:Verdana;">%, </span><span style="font-family:Verdana;">21.23</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 1.48</span><span style="font-family:Verdana;">%, and </span><span style="font-family:Verdana;">0.84</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.11</span><span><span style="font-family:Verdana;">%, respectively for traditionally made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. The result of all physicochemical parameters of traditional <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> was not significantly) different (P</span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) with laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> (control sample).The average (±SD) total bacteria count (TBC), coliform count (CC), yeast and mould count (YMC), Staphylococcus aureus count and Listeria monocytogenes count were </span></span><span style="font-family:""><span style="font-family:Verdana;">8.36 ± 1.29</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">3.47 ± 0.51</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">8.06 ± 1.28</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">3.79 ± 0.91</span><span style="font-family:Verdana;"> and </span><span style="font-family:Verdana;">3.15</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">±</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.17</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">log</span><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">cfu/ml, respectively for traditional <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. Whereas, the </span><span style="font-family:Verdana;">corresponding values for the laboratory-made </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;"> were </span></span><span style="font-family:""><span style="font-family:Verdana;">4.17 ± 0.55</span><span><span style="font-family:Verdana;"> log</span><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">cfu/ml,</span></span></span><span style="font-family:Verdana;"> 0, </span><span style="font-family:""><span style="font-family:Verdana;">5.76 ± 0.57</span><span style="font-family:Verdana;"> log<sub>10</sub>cfu/ml, 0 and 0, respectively. Significant (P</span></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) differences were observed between traditional and laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> for coliform, S. aureus and L. monocytogenes count. The Prevalence of pathogenic microorganisms for S. aureus and L. monocytogenes were </span></span><span style="font-family:""><span style="font-family:Verdana;">33.33% and 6.67%, </span><span><span style="font-family:Verdana;">respectively for traditionally made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i></span></span></span><i><span style="font-family:""> </span></i><span style="font-family:""><span style="font-family:Verdana;">while not detected for laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. The results indicated that the quality of traditional </span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"> was substandard and not safe for consumption. This in general, the production of <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> in the study area requires intervention such as awareness creation of keeping good hygienic quality and pasteurization (heating up to boiling) of milk to be used for</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> making in order to make it safe from the public health point of view.展开更多
Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and th...Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and thermal properties of sintered lunar regolith are vital performance indices for the structural design of a lunar base and analysis of many critical mechanical and thermal issues.In this study,the HUST-1 lunar regolith simulant(HLRS)was sintered at 1030,1040,1050,1060,1070,and 1080℃.The effect of sintering temperature on the compressive strength was investigated,and the exact value of the optimum vacuum sintering temperature was determined between 1040 and 1060℃.Then,the microstructure and material composition of vacuum sintered HLRS at different temperatures were characterized.It was found that the sintering temperature has no significant effect on the mineral composition in the temperature range of 1030-1080℃.Besides,the heat capacity,thermal conductivity,and coefficient of thermal expansion(CTE)of vacuum sintered HLRS at different temperatures were investigated.Specific heat capacity of sintered samples increases with the increase of test temperature within the temperature range from-75 to 145℃.Besides,the thermal conductivity of the sintered sample is proportional to density.Finally,the two temperatures of 1040 and 1050℃were selected for a more detailed study of mechanical properties.The results showed that compressive strength of sintered sample is much higher than tensile strength.This study reveals the effects of sintering temperature on the physical,mechanical and thermal properties of vacuum sintered HLRS,and these material parameters will provide support for the construction of future lunar bases.展开更多
Microbiologically influenced corrosion is a global problem especially materials used in marine engineering.In that respect,inhibitors are widely used to control fouling and corrosion in marine systems.Most techniques ...Microbiologically influenced corrosion is a global problem especially materials used in marine engineering.In that respect,inhibitors are widely used to control fouling and corrosion in marine systems.Most techniques used in inhibitor production are expensive and considered hazardous to the ecosystem.Therefore,scientists are motivated to explore natsural and green products as potent corrosion inhibitors especially in nano size.In this study,antibacterial and anticorrosive properties of green silver nanoparticles(AgNPs)were studied through weight loss,electrochemical characterization,and surface analysis techniques.The corrosion of copper(Cu)in artificial seawater(ASW),Halomonas variabilis(H.variabilis)NOSK,and H.variabilis+AgNPs was monitored using electrochemical measurements like open circuit potential(OCP),electrochemical impedance spectroscopy(EIS),and potentiodynamic polarization curves.AgNPs showed excellent antibacterial activity against pathogenic microorganisms.Electrochemical studies demonstrate a noticeable decrease in OCP and current density in ASW containing H.variabilis+AgNPs compared to both ASW and ASW inoculated with bacterium,which confirmed the decrease of corrosion rate of copper.Furthermore,the obtained voltammograms show that the silver nanoparticles were adsorbed on the copper electrode surface from the corrosion solution.Thus,the results prove that the novel idea of green silver nanoparticles acts as an anticorrosive film in the marine environment.展开更多
Magnesium(Mg)alloys have shown great prospects as both structural and biomedical materials,while poor corrosion resistance limits their further application.In this work,to avoid the time-consuming and laborious experi...Magnesium(Mg)alloys have shown great prospects as both structural and biomedical materials,while poor corrosion resistance limits their further application.In this work,to avoid the time-consuming and laborious experiment trial,a high-throughput computational strategy based on first-principles calculations is designed for screening corrosion-resistant binary Mg alloy with intermetallics,from both the thermodynamic and kinetic perspectives.The stable binary Mg intermetallics with low equilibrium potential difference with respect to the Mg matrix are firstly identified.Then,the hydrogen adsorption energies on the surfaces of these Mg intermetallics are calculated,and the corrosion exchange current density is further calculated by a hydrogen evolution reaction(HER)kinetic model.Several intermetallics,e.g.Y_(3)Mg,Y_(2)Mg and La_(5)Mg,are identified to be promising intermetallics which might effectively hinder the cathodic HER.Furthermore,machine learning(ML)models are developed to predict Mg intermetallics with proper hydrogen adsorption energy employing work function(W_(f))and weighted first ionization energy(WFIE).The generalization of the ML models is tested on five new binary Mg intermetallics with the average root mean square error(RMSE)of 0.11 eV.This study not only predicts some promising binary Mg intermetallics which may suppress the galvanic corrosion,but also provides a high-throughput screening strategy and ML models for the design of corrosion-resistant alloy,which can be extended to ternary Mg alloys or other alloy systems.展开更多
The laser powder bed fusion(LPBF) process can integrally form geometrically complex and high-performance metallic parts that have attracted much interest,especially in the molds industry.The appearance of the LPBF mak...The laser powder bed fusion(LPBF) process can integrally form geometrically complex and high-performance metallic parts that have attracted much interest,especially in the molds industry.The appearance of the LPBF makes it possible to design and produce complex conformal cooling channel systems in molds.Thus,LPBF-processed tool steels have attracted more and more attention.The complex thermal history in the LPBF process makes the microstructural characteristics and properties different from those of conventional manufactured tool steels.This paper provides an overview of LPBF-processed tool steels by describing the physical phenomena,the microstructural characteristics,and the mechanical/thermal properties,including tensile properties,wear resistance,and thermal properties.The microstructural characteristics are presented through a multiscale perspective,ranging from densification,meso-structure,microstructure,substructure in grains,to nanoprecipitates.Finally,a summary of tool steels and their challenges and outlooks are introduced.展开更多
Bacterial resistance and excessive inflammation are common issues that hinder wound healing.Antimicrobial peptides(AMPs)offer a promising and versatile antibacterial option compared to traditional antibiotics,with add...Bacterial resistance and excessive inflammation are common issues that hinder wound healing.Antimicrobial peptides(AMPs)offer a promising and versatile antibacterial option compared to traditional antibiotics,with additional anti-inflammatory properties.However,the applications of AMPs are limited by their antimicrobial effects and stability against bacterial degradation.TFNAs are regarded as a promising drug delivery platform that could enhance the antibacterial properties and stability of nanodrugs.Therefore,in this study,a composite hydrogel(HAMA/t-GL13K)was prepared via the photocross-linking method,in which tFNAs carry GL13K.The hydrogel was injectable,biocompatible,and could be instantly photocured.It exhibited broad-spectrum antibacterial and anti-inflammatory properties by inhibiting the expression of inflammatory factors and scavenging ROS.Thereby,the hydrogel inhibited bacterial infection,shortened the wound healing time of skin defects in infected skin full-thickness defect wound models and reduced scarring.The constructed HAMA/tFNA-AMPs hydrogels exhibit the potential for clinical use in treating microbial infections and promoting wound healing.展开更多
In this investigation,a high-strength Mg-12Gd-1.0Er-0.5Zr(wt.%)alloy sheet was produced by hot extrusion(HE)and subsequent hard-plate rolling(HPR)at different temperatures.The results indicate that the microstructures...In this investigation,a high-strength Mg-12Gd-1.0Er-0.5Zr(wt.%)alloy sheet was produced by hot extrusion(HE)and subsequent hard-plate rolling(HPR)at different temperatures.The results indicate that the microstructures of these final-rolled sheets are inhomogeneous,mainly including coarse deformed grains and dynamic recrystallized(DRXed)grains,and the volume fraction of these coarse deformed grains increases as the rolling temperature increases.Thus,more DRXed grains can be found in R-385℃sheet,resulting in a smaller average grain size and weaker basal texture,while the biggest grains and the highest strong basal texture are present in R-450℃sheet.Amounts of dynamic precipitation ofβphases which are mainly determined by the rolling temperature are present in these sheets,and its precipitation can consume the content of Gd solutes in the matrix.As a result,the lowest number density ofβphase in R-450℃sheet is beneficial to modify the age hardening response.Thus,the R-450℃sheet displays the best age hardening response because of a severe traditional precipitation ofβ’(more)andβH/βM(less)precipitates,resulting in a sharp improvement in strength,i.e.ultimate tensile strength(UTS)of∼518±17 MPa and yield strength(YS)of∼438±18 MPa.However,the elongation(EL)of this sheet reduces greatly,and its value is∼2.7±0.3%.By contrasting,the EL of the peak-aging R-385℃sheet keeps better,changing from∼4.9±1.2%to∼4.8±1.4%due to a novel dislocation-induced chain-like precipitate which is helpful to keep good balance between strength and ductility.展开更多
Amid the scarcity of lunar meteorites and the imperative to preserve their scientific value,nondestructive testing methods are essential.This translates into the application of microscale rock mechanics experiments an...Amid the scarcity of lunar meteorites and the imperative to preserve their scientific value,nondestructive testing methods are essential.This translates into the application of microscale rock mechanics experiments and scanning electron microscopy for surface composition analysis.This study explores the application of Machine Learning algorithms in predicting the mineralogical and mechanical properties of DHOFAR 1084,JAH 838,and NWA 11444 lunar meteorites based solely on their atomic percentage compositions.Leveraging a prior-data fitted network model,we achieved near-perfect classification scores for meteorites,mineral groups,and individual minerals.The regressor models,notably the KNeighbor model,provided an outstanding estimate of the mechanical properties—previously measured by nanoindentation tests—such as hardness,reduced Young’s modulus,and elastic recovery.Further considerations on the nature and physical properties of the minerals forming these meteorites,including porosity,crystal orientation,or shock degree,are essential for refining predictions.Our findings underscore the potential of Machine Learning in enhancing mineral identification and mechanical property estimation in lunar exploration,which pave the way for new advancements and quick assessments in extraterrestrial mineral mining,processing,and research.展开更多
Mg-6Zn-2X(Fe/Cu/Ni)alloys were prepared through semi-continuous casting,with the aim of identifying a degradable magnesium(Mg)alloy suitable for use in fracturing balls.A comparative analysis was conducted to assess t...Mg-6Zn-2X(Fe/Cu/Ni)alloys were prepared through semi-continuous casting,with the aim of identifying a degradable magnesium(Mg)alloy suitable for use in fracturing balls.A comparative analysis was conducted to assess the impacts of adding Cu and Ni,which result in finer grains and the formation of galvanic corrosion sites.Scanner electronic microscopy examination revealed that precipitated phases concentrated at grain boundaries,forming a semi-continuous network structure that facilitated corrosion penetration in Mg-6Zn-2Cu and Mg-6Zn-2Ni alloys.Pitting corrosion was observed in Mg-6Zn-2Fe,while galvanic corrosion was identified as the primary mechanism in Mg-6Zn-2Cu and Mg-6Zn-2Ni alloys.Among the tests,the Mg-6Zn-2Ni alloy exhibited the highest corrosion rate(approximately 932.9 mm/a)due to its significant potential difference.Mechanical testing showed that Mg-6Zn-2Ni alloy possessed suitable ultimate compressive strength,making it a potential candidate material for degradable fracturing balls,effectively addressing the challenges of balancing strength and degradation rate in fracturing applications.展开更多
Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips.The results show that in the first rolling pass,the ro...Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips.The results show that in the first rolling pass,the rolling reduction rate of a conventionally rolled sample(at room temperature)is 33.8%,which can be increased to 41.5%by pulsed current-assisted rolling,enabling the formation of an ultra-thin strip with a size of 67.3μm in only one rolling pass.After three passes of pulsed current-assisted rolling,the thickness of the ultra-thin strip can be further reduced to 51.7μm.To clearly compare the effects of a pulsed current on the microstructure and mechanical response of the ultra-thin strip,ultra-thin strips with nearly the same thickness reduction were analyzed.It was found that pulsed current can reduce the degree of work-hardening of the rolled samples by promoting dislocation detachment,reducing the density of stacking faults,inhibiting martensitic phase transformation,and shortening the total length of grain boundaries.As a result,the ductility of ultra-thin strips can be effectively restored to approximately 16.3%while maintaining a high tensile strength of 1118 MPa.Therefore,pulsed current-assisted rolling deformation shows great potential for the formation of ultra-thin strips with a combination of high strength and ductility.展开更多
Within the past ten years,spark plasma sintering(SPS)has become an increasingly popular process for Mg manufacturing.In the SPS process,interparticle diffusion of compressed particles is rapidly achieved due to the co...Within the past ten years,spark plasma sintering(SPS)has become an increasingly popular process for Mg manufacturing.In the SPS process,interparticle diffusion of compressed particles is rapidly achieved due to the concept of Joule heating.Compared to traditional and additive manufacturing(AM)techniques,SPS gives unique control of the structural and microstructural features of Mg components.By doing so,their mechanical,tribological,and corrosion properties can be tailored.Although great advancements in this field have been made,these pieces of knowledge are scattered and have not been contextualized into a single work.The motivation of this work is to address this scientific gap and to provide a groundwork for understanding the basics of SPS manufacturing for Mg.To do so,the existing body of SPS Mg literature was first surveyed,with a focus on their structural formation and degradation mechanisms.It was found that successful Mg SPS fabrication highly depended on the processing temperature,particle size,and particle crystallinity.The addition of metal and ceramic composites also affected their microstructural features due to the Zener pinning effect.In degradative environments,their performance depends on their structural features and whether they have secondary phased composites.In industrial applications,SPS'd Mg was found to have great potential in biomedical,hydrogen storage,battery,automotive,and recycling sectors.The prospects to advance the field include using Mg as a doping agent for crystallite size refinement and using bulk metallic Mg-based glass powders for amorphous SPS components.Despite these findings,the interactions of multi-composites on the processing-structure-property relationships of SPS Mg is not well understood.In total,this work will provide a useful direction in the SPS field and serve as a milestone for future Mg-based SPS manufacturing.展开更多
Pearl millet(Pennisetum glaucum)is one of the major millets with high nutritional properties.This crop exhibits exceptional resilience to drought and high temperatures.However,the processing of pearl millet poses a si...Pearl millet(Pennisetum glaucum)is one of the major millets with high nutritional properties.This crop exhibits exceptional resilience to drought and high temperatures.However,the processing of pearl millet poses a significant challenge due to its high lipid content,enzyme activity,and presence of antinutrients.Consequently,it becomes imperative to enhance the quality and prolong the shelf life of pearl millet flour by employing suitable technologies.Hydrothermal treatment in the food industry has long been seen as promising due to its potential to reduce microbial load,inactivate enzymes,and improve nutrient retention.This study aims to investigate the effects of hydrothermal treatment on the quality characteristics of pearl millet.The independent variables of the study were soaking temperature(35,45,55℃),soaking time(2,3,4 h),and steaming time(5,10,15 min).Treatment conditions had a statistically significant effect on nutrient retention.Major antinutrients like tannins and phytates were reduced by 0.99% to 5.94% and 0.36% to 6.00%,respectively,after the treatment.Lipase activity decreased significantly up to 10% with the treatment conditions.The findings of this study could potentially encourage the use of pearl millet flour in the production of various food items and promote the application of hydrothermal treatment in the field of food processing.展开更多
Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process...Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process of long-period stacking ordered(LPSO)structure during solidification and heat treatment and its effect on the mechanical properties of experimental alloys are discussed.Results reveal that the stacking faults and 18R LPSO phases appear in the as-cast Mg-10Gd-4Y-1Zn-0.6Zr and Mg-10Gd-4Y-2Zn-0.6Zr alloys,respectively.After solution treatment,the stacking faults and 18R LPSO phase transform into 14H LPSO phase.The Enthalpies of formation and reaction energy of 14H and 18R LPSO are calculated based on first-principles.Results show that the alloying ability of 18R is stronger than that of 14H.The reaction energies show that the 14H LPSO phase is more stable than the 18R LPSO.The elastic properties of the 14H and 18R LPSO phases are also evaluated by first-principles calculations,and the results are in good agreement with the experimental results.The precipitation of LPSO phase improves the tensile strength,yield strength and elongation of the alloy.After solution treatment,the Mg-10Gd-4Y-2Zn-0.6Zr alloy has the best mechanical properties,and its ultimate tensile strength and yield strength are 278.7 MPa and 196.4 MPa,respectively.The elongation of Mg-10Gd-4Y-2Zn-0.6Zr reaches 15.1,which is higher than that of Mg-10Gd-4Y0.6Zr alloy.The improving mechanism of elastic modulus by the LPSO phases and the influence on the alloy mechanical properties are also analyzed.展开更多
A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles...A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles were investigated.The whiteness,water-holding capacity,storage modulus(G')and texture properties of the MPGs were significantly improved by adding 1%-2%Pickering emulsion(P<0.05).Meanwhile,Raman spectral analysis demonstrated that Pickering emulsion promoted the transformation of secondary structure,enhanced hydrogen bonds and hydrophobic interactions,and promoted the transition of disulfide bond conformation from g-g-g to g-g-t and t-g-t.At an emulsion concentration of 2%,theα-helix content decreased by 10.37%,while theβ-sheet content increased by 7.94%,compared to the control.After F-T cycles,the structure of the MPGs was destroyed,with an increase in hardness and a decrease in whiteness and water-holding capacity,however,the quality degradation of MPGs was reduced with 1%-2%Pickering emulsion.These findings demonstrated that SSOS-Pickering emulsions,as potential fat substitutes,can enhance the gel properties and the F-T stability of MPGs.展开更多
This work studied the microstructure,mechanical properties and damping properties of Mg_(95.34)Ni_(2)Y_(2.66) and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys systematically.The difference in the evolution of the long-period ...This work studied the microstructure,mechanical properties and damping properties of Mg_(95.34)Ni_(2)Y_(2.66) and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys systematically.The difference in the evolution of the long-period stacked ordered(LPSO)phase in the two alloys during heat treatment was the focus.The morphology of the as-cast Mg_(95.34)Ni_(2)Y_(2.66)presented a disordered network.After heat treatment at 773 K for 2 hours,the eutectic phase was integrated into the matrix,and the LPSO phase maintained the 18R structure.As Zn partially replaced Ni,the crystal grains became rounded in the cast alloy,and lamellar LPSO phases and more solid solution atoms were contained in the matrix after heat treatment of the Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloy.Both Zn and the heat treatment had a significant effect on damping.Obvious dislocation internal friction peaks and grain boundary internal friction peaks were found after temperature-dependent damping of the Mg_(95.34)Ni_(2)Y_(2.66)and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys.After heat treatment,the dislocation peak was significantly increased,especially in the alloy Mg_(95.34)Ni_(2)Y_(2).66.The annealed Mg_(95.34)Ni_(2)Y_(2.66)alloy with a rod-shaped LPSO phase exhibited a good damping performance of 0.14 atε=10^(−3),which was due to the difference between the second phase and solid solution atom content.These factors also affected the dynamic modulus of the alloy.The results of this study will help in further development of high-damping magnesium alloys.展开更多
文摘The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this work.The following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution function.The results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient decreases.Additionally,the excess molar volume initially decreases,reaches a minimum,and then increases.The rules of radial distribution functions(RDFs)of characteristic atoms are different.With increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then decreases.This indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.
文摘Turkey is a country producing various kinds of cheese. Tomas cheese is a kind of cheese that is still traditionally produced, and it is not widely-known. In this study, the characteristic properties of Tomas cheese, a local product that is extensively consumed in the city of Tunceli and its environs, have been examined. For this purpose, samples from cheese varieties currently on sale in the cities of Tunceli and Elazl~ have been taken, and some of their physico-chemical and microbiological properties have been determined. The results of physico-chemical analysis showed that the average moisture rate of the samples was 53.24%, average ash rate 4.24%, average dry matter 46.76%, average acidity rate in terms of lactic acid 1.08%, average salt rate 2.93%, average fat rate 17.66%, average fat-free dry matter rate 25.56% and average pH value 4.67. The microbiological analysis data showed that the average values for the total aerobic mesophyll bacteria (TAMB) was 7 loglo kob/g, 2.3 logl0 kob/g for coliform, 4.6 logl0 kob/g for yeast, 5.5 logl0 kob/g for mold, 6.8 log10 kob/g for Lactococcus spp., and 6.1 log10 kob/g for Lactobacillus spp.. The results show the high variation among samples, proving that there has not been a standard production procedure. It has been established that the hygienic condition of the product changes according to the production process, and the probability for cross contamination is high. A large number of studies need to be carded out for this kind of traditional food items, due to lack of enough literature data in this paper.
文摘A limited number of studies have been conducted on the effects of ozone use on cereal and its components. Starch, an important natural macromolecule, is an essential component of cereals. In present study, the effects of ozone on the structure, physico-chemical and microbiological properties of wheat, corn, potato and rice starches were investigated. Wheat starch, corn starch, potato starch and rice starch water mixtures were prepared in the ratio of 1:9 (dry sample to water ratio) and treated with ozone at a rate of 60 g/h for 1 hour, while unozonated samples were used as controls. Light microscopy represented that the structures of corn and potato starch samples were affected by 1 hr ozonation rather than the structures of wheat and rice starch samples. Colour of ozone-oxidized wheat, corn and potato starch samples could meet the consumer preference due to the higher lightness, higher whiteness and lower chroma value. However, high chroma, high yellownes and low whiteness values of ozonated rice starch is not adequate for consumer desire. Microbiological analysis showed that 1 hr ozonation reduced the total bacteria and mould/yeast counts significantly for all wheat, corn, potato and rice starch samples (P 〈 0.05) due to most probably the reduced pH of samples. Ozonation can be an alternative modification technique, but further research is needed to understand the certain benefits and limitations of ozone applications on starch oxidation for human safety and health.
文摘Abstract Forests have been expanding over typical savanna sites for the past 3000 years in the Neotropics. Such invasion can produce a series of environmental modifications on typical savanna; however, it remains unclear how modifications in soil properties, caused by the encroachment of woody species, facilitate the expansion of forest ecosystems under dystrophic conditions. Here we examined chemical and microbiological changes associ- ated with tree encroachment in oxisols of a Neotropical Savanna at Assis Ecological Station, Southeastern Brazil. We predicted that tree encroachment caused by typical forest species would cause significant changes in the chemical and microbiological properties of savanna soils. Soils were sampled at Assis Ecological Station, from savanna sites differing in tree encroachment (typical, dense and forested savanna) caused by decades of fire exclusion. We analysed vegetation leaf area index and leaf litter volume deposited in the studied plots and chemical (pH,organic matter, P, K, Ca, Mg, A1, NO3-, NH4+) and microbiological (microbial C biomass and dehydrogenase activity) properties of soils under distinct encroachment conditions. Most soil chemical properties did not change along the tree encroachment gradient; however, total P, soil organic matter, soil microbial C and dehydrogenase activity increased from typical savanna to forested savanna. The changes in soil organic matter and dehydrogenase activity were correlated with the values of leaf area index and litter volume along the encroachment gradient. Our results demonstrate that forest species can increase carbon and phosphorus supplies in tropical savanna soils.
基金supported by the National Key Research and Development Program of China(2023YFB3711300 and 2021YFF0500300)the Strategic Research and Consulting Project of the Chinese Academy of Engineering(2023-XZ-90 and 2023-JB-09-10)the National Key Research and Development Program of China(2021YFF0500300).
文摘The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and optimization.Thirteen types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial environment.Mechanical,thermal and optical,and radiation-shielding properties are considered.The influencing factors and optimization methods for these properties are analyzed.From the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction materials.Correspondingly,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.
文摘The study was conducted to </span><span style="font-family:""><span style="font-family:Verdana;">investigate </span><span><span style="font-family:Verdana;">the physicochemical properties and microbial quality of <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> produced in the Borana zone</span></span><span style="font-family:Verdana;">. </span><span><span style="font-family:Verdana;">A total number of 35 <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> samples, 30 traditionally made plus 5 laboratories made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>,</span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">were analyzed for their physicochemical properties and microbiological quality</span><span style="font-family:""><span style="font-family:Verdana;">. </span><span style="font-family:Verdana;">The overall average (±SD) values for pH, titratable acidity, total protein, fat, total solids, and ash were </span><span style="font-family:Verdana;">3.59</span></span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;"> ±</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.04</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">2.86</span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.18%</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> 7.26</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.41%</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">9.85</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.73</span><span style="font-family:Verdana;">%, </span><span style="font-family:Verdana;">21.23</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 1.48</span><span style="font-family:Verdana;">%, and </span><span style="font-family:Verdana;">0.84</span></span><span style="font-family:Verdana;">%</span><span style="font-family:""><span style="font-family:Verdana;"> ± 0.11</span><span><span style="font-family:Verdana;">%, respectively for traditionally made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. The result of all physicochemical parameters of traditional <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> was not significantly) different (P</span></span></span><span style="font-family:""> </span><span style="font-family:Verdana;">></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) with laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> (control sample).The average (±SD) total bacteria count (TBC), coliform count (CC), yeast and mould count (YMC), Staphylococcus aureus count and Listeria monocytogenes count were </span></span><span style="font-family:""><span style="font-family:Verdana;">8.36 ± 1.29</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">3.47 ± 0.51</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">8.06 ± 1.28</span><span style="font-family:Verdana;">, </span><span style="font-family:Verdana;">3.79 ± 0.91</span><span style="font-family:Verdana;"> and </span><span style="font-family:Verdana;">3.15</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">±</span><span style="font-family:""> </span><span style="font-family:Verdana;">0.17</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">log</span><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">cfu/ml, respectively for traditional <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. Whereas, the </span><span style="font-family:Verdana;">corresponding values for the laboratory-made </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i></span><span style="font-family:Verdana;"> were </span></span><span style="font-family:""><span style="font-family:Verdana;">4.17 ± 0.55</span><span><span style="font-family:Verdana;"> log</span><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">cfu/ml,</span></span></span><span style="font-family:Verdana;"> 0, </span><span style="font-family:""><span style="font-family:Verdana;">5.76 ± 0.57</span><span style="font-family:Verdana;"> log<sub>10</sub>cfu/ml, 0 and 0, respectively. Significant (P</span></span><span style="font-family:""> </span><span style="font-family:Verdana;"><</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">0.05) differences were observed between traditional and laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> for coliform, S. aureus and L. monocytogenes count. The Prevalence of pathogenic microorganisms for S. aureus and L. monocytogenes were </span></span><span style="font-family:""><span style="font-family:Verdana;">33.33% and 6.67%, </span><span><span style="font-family:Verdana;">respectively for traditionally made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i></span></span></span><i><span style="font-family:""> </span></i><span style="font-family:""><span style="font-family:Verdana;">while not detected for laboratory-made <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i>. The results indicated that the quality of traditional </span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"> was substandard and not safe for consumption. This in general, the production of <i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> in the study area requires intervention such as awareness creation of keeping good hygienic quality and pasteurization (heating up to boiling) of milk to be used for</span></span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">ititu</span></i><span style="font-family:Verdana;"></i> making in order to make it safe from the public health point of view.
基金supported by the National Key Research and Development Program of China(Nos.2021YFF0500300 and 2023YFB3711300)the Strategic Research and Consulting Project of the Chinese Academy of Engineering(Nos.2023-XZ-90 and 2023-JB-09-10).
文摘Establishing a base on the Moon is one of the new goals of human lunar exploration in recent years.Sintered lunar regolith is one of the most potential building materials for lunar bases.The physical,mechanical and thermal properties of sintered lunar regolith are vital performance indices for the structural design of a lunar base and analysis of many critical mechanical and thermal issues.In this study,the HUST-1 lunar regolith simulant(HLRS)was sintered at 1030,1040,1050,1060,1070,and 1080℃.The effect of sintering temperature on the compressive strength was investigated,and the exact value of the optimum vacuum sintering temperature was determined between 1040 and 1060℃.Then,the microstructure and material composition of vacuum sintered HLRS at different temperatures were characterized.It was found that the sintering temperature has no significant effect on the mineral composition in the temperature range of 1030-1080℃.Besides,the heat capacity,thermal conductivity,and coefficient of thermal expansion(CTE)of vacuum sintered HLRS at different temperatures were investigated.Specific heat capacity of sintered samples increases with the increase of test temperature within the temperature range from-75 to 145℃.Besides,the thermal conductivity of the sintered sample is proportional to density.Finally,the two temperatures of 1040 and 1050℃were selected for a more detailed study of mechanical properties.The results showed that compressive strength of sintered sample is much higher than tensile strength.This study reveals the effects of sintering temperature on the physical,mechanical and thermal properties of vacuum sintered HLRS,and these material parameters will provide support for the construction of future lunar bases.
基金This research is funded by the Scientific and Technological Research Council of Turkey(TüBITAK,Project MAG#218 M508).
文摘Microbiologically influenced corrosion is a global problem especially materials used in marine engineering.In that respect,inhibitors are widely used to control fouling and corrosion in marine systems.Most techniques used in inhibitor production are expensive and considered hazardous to the ecosystem.Therefore,scientists are motivated to explore natsural and green products as potent corrosion inhibitors especially in nano size.In this study,antibacterial and anticorrosive properties of green silver nanoparticles(AgNPs)were studied through weight loss,electrochemical characterization,and surface analysis techniques.The corrosion of copper(Cu)in artificial seawater(ASW),Halomonas variabilis(H.variabilis)NOSK,and H.variabilis+AgNPs was monitored using electrochemical measurements like open circuit potential(OCP),electrochemical impedance spectroscopy(EIS),and potentiodynamic polarization curves.AgNPs showed excellent antibacterial activity against pathogenic microorganisms.Electrochemical studies demonstrate a noticeable decrease in OCP and current density in ASW containing H.variabilis+AgNPs compared to both ASW and ASW inoculated with bacterium,which confirmed the decrease of corrosion rate of copper.Furthermore,the obtained voltammograms show that the silver nanoparticles were adsorbed on the copper electrode surface from the corrosion solution.Thus,the results prove that the novel idea of green silver nanoparticles acts as an anticorrosive film in the marine environment.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0701202,No.2017YFB0701500 and No.2020YFB1505901)National Natural Science Foundation of China(General Program No.51474149,52072240)+3 种基金Shanghai Science and Technology Committee(No.18511109300)Science and Technology Commission of the CMC(2019JCJQZD27300)financial support from the University of Michigan and Shanghai Jiao Tong University joint funding,China(AE604401)Science and Technology Commission of Shanghai Municipality(No.18511109302).
文摘Magnesium(Mg)alloys have shown great prospects as both structural and biomedical materials,while poor corrosion resistance limits their further application.In this work,to avoid the time-consuming and laborious experiment trial,a high-throughput computational strategy based on first-principles calculations is designed for screening corrosion-resistant binary Mg alloy with intermetallics,from both the thermodynamic and kinetic perspectives.The stable binary Mg intermetallics with low equilibrium potential difference with respect to the Mg matrix are firstly identified.Then,the hydrogen adsorption energies on the surfaces of these Mg intermetallics are calculated,and the corrosion exchange current density is further calculated by a hydrogen evolution reaction(HER)kinetic model.Several intermetallics,e.g.Y_(3)Mg,Y_(2)Mg and La_(5)Mg,are identified to be promising intermetallics which might effectively hinder the cathodic HER.Furthermore,machine learning(ML)models are developed to predict Mg intermetallics with proper hydrogen adsorption energy employing work function(W_(f))and weighted first ionization energy(WFIE).The generalization of the ML models is tested on five new binary Mg intermetallics with the average root mean square error(RMSE)of 0.11 eV.This study not only predicts some promising binary Mg intermetallics which may suppress the galvanic corrosion,but also provides a high-throughput screening strategy and ML models for the design of corrosion-resistant alloy,which can be extended to ternary Mg alloys or other alloy systems.
基金financial supports provided by the China Scholarship Council(Nos.202206 290061 and 202206290062)。
文摘The laser powder bed fusion(LPBF) process can integrally form geometrically complex and high-performance metallic parts that have attracted much interest,especially in the molds industry.The appearance of the LPBF makes it possible to design and produce complex conformal cooling channel systems in molds.Thus,LPBF-processed tool steels have attracted more and more attention.The complex thermal history in the LPBF process makes the microstructural characteristics and properties different from those of conventional manufactured tool steels.This paper provides an overview of LPBF-processed tool steels by describing the physical phenomena,the microstructural characteristics,and the mechanical/thermal properties,including tensile properties,wear resistance,and thermal properties.The microstructural characteristics are presented through a multiscale perspective,ranging from densification,meso-structure,microstructure,substructure in grains,to nanoprecipitates.Finally,a summary of tool steels and their challenges and outlooks are introduced.
基金supported by National Key R&D Program of China(2019YFA0110600)National Natural Science Foundation of China(82370929,81970916)+2 种基金Sichuan Science and Technology Program(2022NSFSC0002)Sichuan Province Youth Science and Technology Innovation Team(2022JDTD0021)Research and Develop Program,West China Hospital of Stomatology Sichuan University(RD03202302)。
文摘Bacterial resistance and excessive inflammation are common issues that hinder wound healing.Antimicrobial peptides(AMPs)offer a promising and versatile antibacterial option compared to traditional antibiotics,with additional anti-inflammatory properties.However,the applications of AMPs are limited by their antimicrobial effects and stability against bacterial degradation.TFNAs are regarded as a promising drug delivery platform that could enhance the antibacterial properties and stability of nanodrugs.Therefore,in this study,a composite hydrogel(HAMA/t-GL13K)was prepared via the photocross-linking method,in which tFNAs carry GL13K.The hydrogel was injectable,biocompatible,and could be instantly photocured.It exhibited broad-spectrum antibacterial and anti-inflammatory properties by inhibiting the expression of inflammatory factors and scavenging ROS.Thereby,the hydrogel inhibited bacterial infection,shortened the wound healing time of skin defects in infected skin full-thickness defect wound models and reduced scarring.The constructed HAMA/tFNA-AMPs hydrogels exhibit the potential for clinical use in treating microbial infections and promoting wound healing.
基金financially supported by National Key R&D Program of China(No.2021YFB3701100)Beijing Municipal Natural Science Foundation(No.2202004).
文摘In this investigation,a high-strength Mg-12Gd-1.0Er-0.5Zr(wt.%)alloy sheet was produced by hot extrusion(HE)and subsequent hard-plate rolling(HPR)at different temperatures.The results indicate that the microstructures of these final-rolled sheets are inhomogeneous,mainly including coarse deformed grains and dynamic recrystallized(DRXed)grains,and the volume fraction of these coarse deformed grains increases as the rolling temperature increases.Thus,more DRXed grains can be found in R-385℃sheet,resulting in a smaller average grain size and weaker basal texture,while the biggest grains and the highest strong basal texture are present in R-450℃sheet.Amounts of dynamic precipitation ofβphases which are mainly determined by the rolling temperature are present in these sheets,and its precipitation can consume the content of Gd solutes in the matrix.As a result,the lowest number density ofβphase in R-450℃sheet is beneficial to modify the age hardening response.Thus,the R-450℃sheet displays the best age hardening response because of a severe traditional precipitation ofβ’(more)andβH/βM(less)precipitates,resulting in a sharp improvement in strength,i.e.ultimate tensile strength(UTS)of∼518±17 MPa and yield strength(YS)of∼438±18 MPa.However,the elongation(EL)of this sheet reduces greatly,and its value is∼2.7±0.3%.By contrasting,the EL of the peak-aging R-385℃sheet keeps better,changing from∼4.9±1.2%to∼4.8±1.4%due to a novel dislocation-induced chain-like precipitate which is helpful to keep good balance between strength and ductility.
基金EP-A and JMT-R acknowledges financial support from the project PID2021-128062NB-I00 funded by MCIN/AEI/10.13039/501100011033The lunar samples studied here were acquired in the framework of grant PGC2018-097374-B-I00(P.I.JMT-R)+3 种基金This project has received funding from the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(No.865657)for the project“Quantum Chemistry on Interstellar Grains”(QUANTUMGRAIN),AR acknowledges financial support from the FEDER/Ministerio de Ciencia e Innovación-Agencia Estatal de Investigación(No.PID2021-126427NB-I00)Partial financial support from the Spanish Government(No.PID2020-116844RB-C21)the Generalitat de Catalunya(No.2021-SGR-00651)is acknowledgedThis work was supported by the LUMIO project funded by the Agenzia Spaziale Italiana(No.2024-6-HH.0).
文摘Amid the scarcity of lunar meteorites and the imperative to preserve their scientific value,nondestructive testing methods are essential.This translates into the application of microscale rock mechanics experiments and scanning electron microscopy for surface composition analysis.This study explores the application of Machine Learning algorithms in predicting the mineralogical and mechanical properties of DHOFAR 1084,JAH 838,and NWA 11444 lunar meteorites based solely on their atomic percentage compositions.Leveraging a prior-data fitted network model,we achieved near-perfect classification scores for meteorites,mineral groups,and individual minerals.The regressor models,notably the KNeighbor model,provided an outstanding estimate of the mechanical properties—previously measured by nanoindentation tests—such as hardness,reduced Young’s modulus,and elastic recovery.Further considerations on the nature and physical properties of the minerals forming these meteorites,including porosity,crystal orientation,or shock degree,are essential for refining predictions.Our findings underscore the potential of Machine Learning in enhancing mineral identification and mechanical property estimation in lunar exploration,which pave the way for new advancements and quick assessments in extraterrestrial mineral mining,processing,and research.
基金financially supported by the Key Scientific Research Project in Shanxi Province,China(No.202102050201003)the National Natural Science Foundation of China(No.52071227)+2 种基金the Natural Science Foundation of Shanxi Province,China(No.202103021223293)the Central Guiding Science and Technology Development of Local Fund,China(No.YDZJSK20231A046)the Postgraduate Education Innovation Project of Shanxi Province,China(No.2023Y686)。
文摘Mg-6Zn-2X(Fe/Cu/Ni)alloys were prepared through semi-continuous casting,with the aim of identifying a degradable magnesium(Mg)alloy suitable for use in fracturing balls.A comparative analysis was conducted to assess the impacts of adding Cu and Ni,which result in finer grains and the formation of galvanic corrosion sites.Scanner electronic microscopy examination revealed that precipitated phases concentrated at grain boundaries,forming a semi-continuous network structure that facilitated corrosion penetration in Mg-6Zn-2Cu and Mg-6Zn-2Ni alloys.Pitting corrosion was observed in Mg-6Zn-2Fe,while galvanic corrosion was identified as the primary mechanism in Mg-6Zn-2Cu and Mg-6Zn-2Ni alloys.Among the tests,the Mg-6Zn-2Ni alloy exhibited the highest corrosion rate(approximately 932.9 mm/a)due to its significant potential difference.Mechanical testing showed that Mg-6Zn-2Ni alloy possessed suitable ultimate compressive strength,making it a potential candidate material for degradable fracturing balls,effectively addressing the challenges of balancing strength and degradation rate in fracturing applications.
基金This work was supported by the fund of the National Natural Science Foundation of China(51974196)Major Program of National Natural Science Foundation of China(U22A20188)+1 种基金Science and Technology Innovation Teams of Shanxi Province(202304051001025)Central Government Guides the Special Fund Projects of Local Scientific and Technological Development(YDZX20191400002149).
文摘Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips.The results show that in the first rolling pass,the rolling reduction rate of a conventionally rolled sample(at room temperature)is 33.8%,which can be increased to 41.5%by pulsed current-assisted rolling,enabling the formation of an ultra-thin strip with a size of 67.3μm in only one rolling pass.After three passes of pulsed current-assisted rolling,the thickness of the ultra-thin strip can be further reduced to 51.7μm.To clearly compare the effects of a pulsed current on the microstructure and mechanical response of the ultra-thin strip,ultra-thin strips with nearly the same thickness reduction were analyzed.It was found that pulsed current can reduce the degree of work-hardening of the rolled samples by promoting dislocation detachment,reducing the density of stacking faults,inhibiting martensitic phase transformation,and shortening the total length of grain boundaries.As a result,the ductility of ultra-thin strips can be effectively restored to approximately 16.3%while maintaining a high tensile strength of 1118 MPa.Therefore,pulsed current-assisted rolling deformation shows great potential for the formation of ultra-thin strips with a combination of high strength and ductility.
文摘Within the past ten years,spark plasma sintering(SPS)has become an increasingly popular process for Mg manufacturing.In the SPS process,interparticle diffusion of compressed particles is rapidly achieved due to the concept of Joule heating.Compared to traditional and additive manufacturing(AM)techniques,SPS gives unique control of the structural and microstructural features of Mg components.By doing so,their mechanical,tribological,and corrosion properties can be tailored.Although great advancements in this field have been made,these pieces of knowledge are scattered and have not been contextualized into a single work.The motivation of this work is to address this scientific gap and to provide a groundwork for understanding the basics of SPS manufacturing for Mg.To do so,the existing body of SPS Mg literature was first surveyed,with a focus on their structural formation and degradation mechanisms.It was found that successful Mg SPS fabrication highly depended on the processing temperature,particle size,and particle crystallinity.The addition of metal and ceramic composites also affected their microstructural features due to the Zener pinning effect.In degradative environments,their performance depends on their structural features and whether they have secondary phased composites.In industrial applications,SPS'd Mg was found to have great potential in biomedical,hydrogen storage,battery,automotive,and recycling sectors.The prospects to advance the field include using Mg as a doping agent for crystallite size refinement and using bulk metallic Mg-based glass powders for amorphous SPS components.Despite these findings,the interactions of multi-composites on the processing-structure-property relationships of SPS Mg is not well understood.In total,this work will provide a useful direction in the SPS field and serve as a milestone for future Mg-based SPS manufacturing.
基金the Ministry of Human Resource Development,Govt.of India,for providing scholarship grants to the authors.
文摘Pearl millet(Pennisetum glaucum)is one of the major millets with high nutritional properties.This crop exhibits exceptional resilience to drought and high temperatures.However,the processing of pearl millet poses a significant challenge due to its high lipid content,enzyme activity,and presence of antinutrients.Consequently,it becomes imperative to enhance the quality and prolong the shelf life of pearl millet flour by employing suitable technologies.Hydrothermal treatment in the food industry has long been seen as promising due to its potential to reduce microbial load,inactivate enzymes,and improve nutrient retention.This study aims to investigate the effects of hydrothermal treatment on the quality characteristics of pearl millet.The independent variables of the study were soaking temperature(35,45,55℃),soaking time(2,3,4 h),and steaming time(5,10,15 min).Treatment conditions had a statistically significant effect on nutrient retention.Major antinutrients like tannins and phytates were reduced by 0.99% to 5.94% and 0.36% to 6.00%,respectively,after the treatment.Lipase activity decreased significantly up to 10% with the treatment conditions.The findings of this study could potentially encourage the use of pearl millet flour in the production of various food items and promote the application of hydrothermal treatment in the field of food processing.
基金supported by the National Key Research and Development Program of China[grant No.2018YFB2001800]National Natural Science Foundation of China[grant No.51871184]Dalian High-level Talents Innovation Support Program[grant No.2021RD06]。
文摘Based on experiments and first-principles calculations,the microstructures and mechanical properties of as-cast and solution treated Mg-10Gd-4Y-xZn-0.6Zr(x=0,1,2,wt.%)alloys are investigated.The transformation process of long-period stacking ordered(LPSO)structure during solidification and heat treatment and its effect on the mechanical properties of experimental alloys are discussed.Results reveal that the stacking faults and 18R LPSO phases appear in the as-cast Mg-10Gd-4Y-1Zn-0.6Zr and Mg-10Gd-4Y-2Zn-0.6Zr alloys,respectively.After solution treatment,the stacking faults and 18R LPSO phase transform into 14H LPSO phase.The Enthalpies of formation and reaction energy of 14H and 18R LPSO are calculated based on first-principles.Results show that the alloying ability of 18R is stronger than that of 14H.The reaction energies show that the 14H LPSO phase is more stable than the 18R LPSO.The elastic properties of the 14H and 18R LPSO phases are also evaluated by first-principles calculations,and the results are in good agreement with the experimental results.The precipitation of LPSO phase improves the tensile strength,yield strength and elongation of the alloy.After solution treatment,the Mg-10Gd-4Y-2Zn-0.6Zr alloy has the best mechanical properties,and its ultimate tensile strength and yield strength are 278.7 MPa and 196.4 MPa,respectively.The elongation of Mg-10Gd-4Y-2Zn-0.6Zr reaches 15.1,which is higher than that of Mg-10Gd-4Y0.6Zr alloy.The improving mechanism of elastic modulus by the LPSO phases and the influence on the alloy mechanical properties are also analyzed.
基金supported by the National Natural Science Foundation of China(U20A2067,32272360)。
文摘A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles were investigated.The whiteness,water-holding capacity,storage modulus(G')and texture properties of the MPGs were significantly improved by adding 1%-2%Pickering emulsion(P<0.05).Meanwhile,Raman spectral analysis demonstrated that Pickering emulsion promoted the transformation of secondary structure,enhanced hydrogen bonds and hydrophobic interactions,and promoted the transition of disulfide bond conformation from g-g-g to g-g-t and t-g-t.At an emulsion concentration of 2%,theα-helix content decreased by 10.37%,while theβ-sheet content increased by 7.94%,compared to the control.After F-T cycles,the structure of the MPGs was destroyed,with an increase in hardness and a decrease in whiteness and water-holding capacity,however,the quality degradation of MPGs was reduced with 1%-2%Pickering emulsion.These findings demonstrated that SSOS-Pickering emulsions,as potential fat substitutes,can enhance the gel properties and the F-T stability of MPGs.
基金funded by the National Natural Science Foundation of China(Nos.51801189)The Central Guidance on Local Science and Technology Development Fund of Shanxi Province(Nos.YDZJTSX2021A027)+2 种基金The National Natural Science Foundation of China(Nos.51801189)The Science and Technology Major Project of Shanxi Province(No.20191102008,20191102007)The North University of China Youth Academic Leader Project(No.11045505).
文摘This work studied the microstructure,mechanical properties and damping properties of Mg_(95.34)Ni_(2)Y_(2.66) and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys systematically.The difference in the evolution of the long-period stacked ordered(LPSO)phase in the two alloys during heat treatment was the focus.The morphology of the as-cast Mg_(95.34)Ni_(2)Y_(2.66)presented a disordered network.After heat treatment at 773 K for 2 hours,the eutectic phase was integrated into the matrix,and the LPSO phase maintained the 18R structure.As Zn partially replaced Ni,the crystal grains became rounded in the cast alloy,and lamellar LPSO phases and more solid solution atoms were contained in the matrix after heat treatment of the Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloy.Both Zn and the heat treatment had a significant effect on damping.Obvious dislocation internal friction peaks and grain boundary internal friction peaks were found after temperature-dependent damping of the Mg_(95.34)Ni_(2)Y_(2.66)and Mg_(95.34)Zn_(1)Ni_(1)Y_(2.66)alloys.After heat treatment,the dislocation peak was significantly increased,especially in the alloy Mg_(95.34)Ni_(2)Y_(2).66.The annealed Mg_(95.34)Ni_(2)Y_(2.66)alloy with a rod-shaped LPSO phase exhibited a good damping performance of 0.14 atε=10^(−3),which was due to the difference between the second phase and solid solution atom content.These factors also affected the dynamic modulus of the alloy.The results of this study will help in further development of high-damping magnesium alloys.