Europium and terbium coordination polymers of pyridine-3-carboxylic acid were in-situ composed with ethyt methacrylate ( EMA ). With the polymerization of EMA monomer and the formation of europium and terbium coordi...Europium and terbium coordination polymers of pyridine-3-carboxylic acid were in-situ composed with ethyt methacrylate ( EMA ). With the polymerization of EMA monomer and the formation of europium and terbium coordination polymers of pyridiae- 3-carboxylic acid, the transparent hybrid thick fihns composed of [ Eu( NIC )3 ]n ( [ Tb( NIC)3 ]n ) and poly ethyl mettuwrylate ( PEMA ) have been prepared. The luminescence properties and energy transfer of these polymeric composites were studied with absorption spectra, fluorescent excitation trod emission spectra in detail. All the hybrid thick films composed of terbium coordination polymer show the characteristic strong green emission of terbium ions, which implies the same energy transfer mechanism as the pure complex and the hybrid composite film is a suitable sabstrate for the luminescence of terbium ions. In the range of camposing concentration of luminescent species (0.01,0.025,0.05,0.1 mmol /15 mL EMA ), emission intensities increase with the increasing of corresponding composing concentration and the concentration quenching effect does not take place.展开更多
Gualou-Xiebai-Banxia Decoction(GXBD)is a traditional Chinese herbal formula including four traditional Chinese medicines:Gualou(Trichosanthis Fructus,TF),Xiebai(Allii Macrostemonis Bulbus,AMB),Banxia(Pinelliae Rhizoma...Gualou-Xiebai-Banxia Decoction(GXBD)is a traditional Chinese herbal formula including four traditional Chinese medicines:Gualou(Trichosanthis Fructus,TF),Xiebai(Allii Macrostemonis Bulbus,AMB),Banxia(Pinelliae Rhizoma,PR)and yellow wine.It is a classical therapy for chest stuffiness and pain syndrome and is widely used in the clinical treatment of coronary heart disease.It also shows significant therapeutic effects on pulmonary heart disease,hyperlipidemia,and arrhythmia.This study conducted a literature review and collected information on GXBD from databases such as PubMed,Web of Science,China National Knowledge Infrastructure,and ScienceDirect.The result indicated that the main active ingredients of GXBD are steroids,flavonoids,terpenoids,alkaloids,amino acids,and organic acids.Trigonelline,macrostemonoside and cucurbitacin B can provide reference for its quality control.GXBD may exert therapeutic effects on coronary heart disease through AMPK,PI3K-AKT,oxLDL,VEGF,and NF-κB signal pathways.This review provides a comprehensive analysis and summary of the chemical composition and in vivo metabolism of three traditional Chinese medicines(TF,AMB,and PR),along with an evaluation of the chemical composition,quality control,pharmacological effects,and clinical application of GXBD.Based on these,areas requiring further research on GXBD have been proposed to provide a reference for its further development and new drug research.展开更多
BACKGROUND Body composition analysis(BCA)is primarily used in the management of conditions such as obesity and endocrine disorders.However,its potential in providing nutritional guidance for patients with Alzheimer’s...BACKGROUND Body composition analysis(BCA)is primarily used in the management of conditions such as obesity and endocrine disorders.However,its potential in providing nutritional guidance for patients with Alzheimer’s disease(AD)remains relatively unexplored.AIM To explore the clinical efficacy of BCA-based dietary nutrition scheme on bone metabolism in AD patients.METHODS This retrospective study included 96 patients with AD complicated by osteoporosis who were admitted to The Third Hospital of Quzhou between January 2023 and December 2024.Based on data from previous similar studies,the patients were randomly assigned to either a routine diet(RD)group(n=48)or a personalized nutrition(PN)group(n=48).The RD group received conventional dietary guidance,while the PN group received individualized diet intervention measures based on human BCA.The intervention period lasted for 12 weeks.Bone mineral density(BMD),body mass index(BMI),muscle mass,mineral content,osteocalcin,25-hydroxyvitamin D,procollagen type I N-terminal propeptide(PINP),beta C-terminal telopeptide of type I collagen(β-CTX),and serum calcium were measured and compared between the two groups before and 12 weeks after the intervention.RESULTS No significant differences were observed between groups in terms of age,sex,height,BMI,or other baseline data(P>0.05).In both groups,BMI did not show significant changes after the intervention(P>0.05),whereas muscle mass and mineral content were significantly increased(P<0.05).After the intervention,BMI in the PN group did not differ significantly from that of the RD group,but muscle mass and mineral content were significantly higher in the PN group(P<0.05).After the intervention,a higher proportion of patients in the PN group had a T score>-1 compared to the RD group(P<0.05).The mini-mental state examination(MMSE)score was similar in both groups before the intervention.However,12 weeks after the intervention,the MMSE score in the PN group was significantly higher than that in the RD group(P<0.05).In both groups,the MMSE score significantly increased 12 weeks post-intervention compared to pre-intervention levels(P<0.05).Before the intervention,the levels of osteocalcin,serum calcium,PINP,β-CTX,and 25-hydroxyvitamin D were not significantly different between the two groups(P>0.05).After 12 weeks of intervention,the PN group exhibited higher levels of osteocalcin,serum calcium,and 25-hydroxyvitamin D,as well as lower levels of PINP andβ-CTX,compared to the RD group(P<0.05).In both groups,osteocalcin,serum calcium,and 25-hydroxyvitamin D levels were significantly higher,while PINP andβ-CTX levels were significantly lower after 12 weeks of intervention compared to baseline(P<0.05).CONCLUSION The human BCA-based dietary nutrition regimen plays a crucial role in improving BMD and bone metabolism,with effects that surpass those of conventional nutrition strategies.The findings of this study provide strong evidence for the nutritional management of AD patients.展开更多
Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based...Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting technique.Microstructural characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were evaluated.Results revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and TiC.However,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like morphology.Microhardness increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature elongation.Conversely,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.展开更多
It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites incl...It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites including those inspired by gradient layered materials.In this work,we used LPBF to selectively prepare Ti N/Ti gradient layered structure(GLSTi)composites by using different N_(2)–Ar ratios during the LPBF process.We systematically investigated the mechanisms of in-situ synthesis Ti N,high strength and ductility of GLSTi composites using microscopic analysis,TEM characterization,and tensile testing with digital image correlation.Besides,a digital correspondence was established between the N_(2) concentration and the volume fraction of LPBF in-situ synthesized Ti N.Our results show that the GLSTi composites exhibit superior mechanical properties compared to pure titanium fabricated by LPBF under pure Ar.Specifically,the tensile strength of GLSTi was more than 1.5times higher than that of LPBF-formed pure titanium,reaching up to 1100 MPa,while maintaining a high elongation at fracture of 17%.GLSTi breaks the bottleneck of high strength but low ductility exhibited by conventional nanoceramic particle-strengthened titanium matrix composites,and the hetero-deformation induced strengthening effect formed by the Ti N/Ti layered structure explained its strength-plasticity balanced principle.The microhardness exhibits a jagged variation of the relatively low hardness of 245 HV0.2 for the pure titanium layer and a high hardness of 408 HV0.2 for the N_(2) in-situ synthesis layer.Our study provides a new concept for the structure-performance digital customization of 3D-printed Ti-based composites.展开更多
Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable M...Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable MAMs under some rigorous conditions,while their composites still fail to produce satisfactory microwave absorption performance regardless of the improvements as compared with the individuals.Herein,we have successfully implemented compositional and structural engineering to fabricate hollow Si C/C microspheres with controllable composition.The simultaneous modulation on dielectric properties and impedance matching can be easily achieved as the change in the composition of these composites.The formation of hollow structure not only favors lightweight feature,but also generates considerable contribution to microwave attenuation capacity.With the synergistic effect of composition and structure,the optimized SiC/C composite exhibits excellent performance,whose the strongest reflection loss intensity and broadest effective absorption reach-60.8 dB and 5.1 GHz,respectively,and its microwave absorption properties are actually superior to those of most SiC/C composites in previous studies.In addition,the stability tests of microwave absorption capacity after exposure to harsh conditions and Radar Cross Section simulation data demonstrate that hollow SiC/C microspheres from compositional and structural optimization have a bright prospect in practical applications.展开更多
Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering th...Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering them incapable of effectively inhibiting the exchange reaction between lithium ions and transition metal ions in the electrolyte.Consequently,nearly all lithium ions within the SEI film are replaced by transition metal ions,resulting in an increase in interphacial impedance and a decrease in stability.Herein,we demonstrate that the SEI film,constructed by fluoroethylene carbonate(FEC)additive rich in crystalline Li F,effectively inhibits the undesired Li^(+)/Co^(2+)ion exchange reaction,thereby suppressing the deposition of cobalt compounds and metallic cobalt.Furthermore,the deposited cobalt compounds exhibit enhanced structural stability and reduced catalytic activity with minimal impact on the interphacial stability of the graphite anode.Our findings reveal the crucial influence of SEI film composition and structure on the deposition and hazards associated with transition metal ions,providing valuable guidance for designing next-generation electrolytes.展开更多
BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relatio...BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relationship between body composition,metabolic syndrome and insulin resistance in T1DM to guide clinical treatment and intervention.AIM To assess body composition(BC)in T1DM patients and evaluate the relationship between BC,metabolic syndrome(MS),and insulin resistance in these indi-viduals.METHODS A total of 101 subjects with T1DM,aged 10 years or older,and with a disease duration of over 1 year were included.Bioelectrical impedance analysis using the Tsinghua-Tongfang BC Analyzer BCA-1B was employed to measure various BC parameters.Clinical and laboratory data were collected,and insulin resistance was calculated using the estimated glucose disposal rate(eGDR).RESULTS MS was diagnosed in 16/101 patients(15.84%),overweight in 16/101 patients(15.84%),obesity in 4/101(3.96%),hypertension in 34/101(33.66%%)and dyslip-idemia in 16/101 patients(15.84%).Visceral fat index(VFI)and trunk fat mass were significantly and negatively correlated with eGDR(both P<0.001).Female patients exhibited higher body fat percentage and visceral fat ratio compared to male patients.Binary logistic regression analysis revealed that significant factors for MS included eGDR[P=0.017,odds ratio(OR)=0.109],VFI(P=0.030,OR=3.529),and a family history of diabetes(P=0.004,OR=0.228).Significant factors for hypertension included eGDR(P<0.001,OR=0.488)and skeletal muscle mass(P=0.003,OR=1.111).Significant factors for dyslipidemia included trunk fat mass(P=0.033,OR=1.202)and eGDR(P=0.037,OR=0.708).CONCLUSION Visceral fat was found to be a superior predictor of MS compared to conventional measures such as body mass index and waist-to-hip ratio in Chinese individuals with T1DM.BC analysis,specifically identifying visceral fat(trunk fat),may play an important role in identifying the increased risk of MS in non-obese patients with T1DM.展开更多
Bidens pilosa is recognized as one of the major invasive plants in China.Its invasion has been associated with significant losses in agriculture,forestry,husbandry,and biodiversity.Soil ecosystems play an important ro...Bidens pilosa is recognized as one of the major invasive plants in China.Its invasion has been associated with significant losses in agriculture,forestry,husbandry,and biodiversity.Soil ecosystems play an important role in alien plant invasion.Microorganisms within the soil act as intermediaries between plants and soil ecological functions,playing a role in regulating soil enzyme activities and nutrient dynamics.Understanding the interactions between invasive plants,soil microorganisms,and soil ecological processes is vital for managing and mitigating the impacts of invasive species on the environment.In this study,we conducted a systematic analysis focusing on B.pilosa and Setaria viridis,a common native companion plant in the invaded area.To simulate the invasion process of B.pilosa,we constructed homogeneous plots consisting of B.pilosa and S.viridis grown separately as monocultures,as well as in mixtures.The rhizosphere and bulk soils were collected from the alien plant B.pilosa and the native plant S.viridis.In order to focus on the soil ecological functional mechanisms that contribute to the successful invasion of B.pilosa,we analyzed the effects of B.pilosa on the composition of soil microbial communities and soil ecological functions.The results showed that the biomass of B.pilosa increased by 27.51% and that of S.viridis was significantly reduced by 66.56%.The organic matter contents in the bulk and rhizosphere soils of B.pilosa were approximately 1.30 times those in the native plant soils.The TN and NO_(3)^(-)contents in the rhizosphere soil of B.pilosa were 1.30 to 2.71 times those in the native plant soils.The activities of acid phosphatase,alkaline phosphatase,and urease in the rhizosphere soil of B.pilosa were 1.98-2.25 times higher than in the native plant soils.Using high-throughput sequencing of the16S rRNA gene,we found that B.pilosa altered the composition of the soil microbial community.Specifically,many genera in Actinobacteria and Proteobacteria were enriched in B.pilosa soils.Further correlation analyses verified that these genera had significantly positive relationships with soil nutrients and enzyme activities.Plant biomass,soil p H,and the contents of organic matter,TN,NO_(3)^(-),TP,AP,TK,and AK were the main factors affecting soil microbial communities.This study showed that the invasion of B.pilosa led to significant alterations in the composition of the soil microbial communities.These changes were closely linked to modifications in plant traits as well as soil physical and chemical properties.Some microbial species related to C,N and P cycling were enriched in the soil invaded by B.pilosa.These findings provide additional support for the hypothesis of soil-microbe feedback in the successful invasion of alien plants.They also offer insights into the ecological mechanism by which soil microbes contribute to the successful invasion of B.pilosa.Overall,our research contributes to a better understanding of the complex interactions between invasive plants,soil microbial communities,and ecosystem dynamics.展开更多
Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pret...Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each proxy.Here,we developed a method by which each proxy can be measured in the same sample.First,the sample is polished for ring width meas-urement.After obtaining the ring width data,the sample is cut to form a 1-mm-thick wood plate.The sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray beam.Simultaneously,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,i.e.the density and the element content are obtained.Then,cellulose is isolated from the 1-mm wood plate by removal of lignin,and hemicellulose.After producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)analysis.Based on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.展开更多
In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active ...In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.展开更多
60% white corundum used for aggregate, 5% aluminium powder for fixed additions and 35% various additives for matrix were prepared for specimens 1#,2#,3#. They were mixed uniformly with the suitable resin as a binder a...60% white corundum used for aggregate, 5% aluminium powder for fixed additions and 35% various additives for matrix were prepared for specimens 1#,2#,3#. They were mixed uniformly with the suitable resin as a binder and pressed under pressure of 315 ton forging press, then dried at 200℃ for 24 h. Effects of various additives on 1500 ℃×2 h creep properties of Al3CON reinforced corundum composite were researched. The experimenal results show that creep coefficients of specimens 1#,2#,3# at 1500 ℃×2 h are 1.4×10^- 4, -9.4×10^-4, -22.6×10^-4, respectively. Crushing strength of the slide plate added with suitable additive A after fired at 1500 ℃ ×3 h reaches to 225 MPa, the creep rate is positive all the time from 0% to 0.014% at 1500 ℃ for 2 h. The microstructure result analysis shows that reinforced phases of Al3CON fiber composite have been formed after fired with Al powder in coke at high temperatures for specimen 1#, and the strength of the composite is increased. The hot modulus of rupture is up to 59 MPa at 1400 ℃ and the RUL is obviously higher than that at 1700 ℃. Its service life is two times as that of Al2O3-C slide plate when used in the process of pouring steel. The mechanism of creep rate resistance of the composites can be discovered by means of SEM and EDAX analysis. It is concluded that the active Al3CON and Al2O3 multiphases that were formed by N2 in gas, C, Al and Al2O3 inside the matrix of the composites during in-situ reaction,which gives the composites outstanding creep rate resistance for the dense zone resuiting from Al3CON oxidation that inhibits contraction at the high temperature. Besides, the matrix will turn into the multiphase with high refractoriness, N content and its Al3CON reinforced fiber will further increase accordingly. In addition, Al3CON formed by Al2O3 and C, Al in the matrix with N2 in gas will inhibit the creep rate and also greatly improve the creep rate resistance of the composites.展开更多
Zeolites ZSM-5 with different Si/Al ratios were in-situ synthesized on the surface ofhoneycomb-shaped cordierite support for the first time. Characterizations of XRD and SEM wereperformed and it has been proved that t...Zeolites ZSM-5 with different Si/Al ratios were in-situ synthesized on the surface ofhoneycomb-shaped cordierite support for the first time. Characterizations of XRD and SEM wereperformed and it has been proved that the zeolite ZSM-5 was grown on the surface of the cordieritehomogeneously. NO decomposition on the Cu exchanged ZSM-5/cordierite monolith catalysts wasalso studied. It was found that the monolith catalysts have a fine initial activity at 673K and GHSVof 10,000h-1. Such method should be a good way to make auto exhaust converter with monolithcatalyst for NOx removal.展开更多
This study aimed to discriminate ten Cameroonian cocoa hybrids according to their total fat, fatty acid composition, tocopherol and tocotrienol profiles. Six cocoa clones from the gene banks of the Cameroon Cocoa Deve...This study aimed to discriminate ten Cameroonian cocoa hybrids according to their total fat, fatty acid composition, tocopherol and tocotrienol profiles. Six cocoa clones from the gene banks of the Cameroon Cocoa Development Corporation were used to create hybrids. The determination of fatty acid composition was carried out by using a gas chromatography (GC) apparatus coupled by a flame ion detector (FID). Tocopherol and tocotrienol analysis was performed by upper high-performance liquid chromatography (UHPLC). Information on the impact of the genotype on the cocoa fat composition was provided. The major fatty acids (FA) in fermented samples are stearic (34.57%), palmitic (26.13%), oleic (34.13%) and linoleic (3.16%) acids. (35.05% to 35.6%). SCA12 × ICS40, SCA12 × SNK13, SNK13 × T79/501 have the least hard cocoa butters. Tocopherols analysis showed a predominance of γ-tocopherols (94.64 ± 1.51 to 292.16 ± 3.17 µg∙g<sup>−1</sup>), whereas only a small amount of β and δ-tocopherol (from 0.46 to 2.78 µg∙g<sup>−1</sup> and 0.12 to 5.82 respectively) was observed. No γ-tocotrienol was found in fermented samples. A differentiation in terms of total fat and tocopherol content was observed amongst hybrids with the same mother-clone, suggesting an impact of pollen on these compounds.展开更多
In-situ LA-ICP-MS and S isotopes of pyrite from the Baoshan Cu polymetallic deposit were conducted to investigate the ore-forming process and the enrichment mechanism of elements.Three generations of pyrite (Py Ⅰ,Py ...In-situ LA-ICP-MS and S isotopes of pyrite from the Baoshan Cu polymetallic deposit were conducted to investigate the ore-forming process and the enrichment mechanism of elements.Three generations of pyrite (Py Ⅰ,Py Ⅱ,and Py Ⅲ) in the skarn-type ores and pyrite in the carbonate-hosted sulfide ores from central,western,and northern(C_Py,W_Py,and N_Py) mining districts are selected for comparison.Compared with Py Ⅰ and Py Ⅲ,the contents of most elements in Py Ⅱ are apparently higher.The As and Se contents are high within a wide range and are decoupled in the growth band of the C_Py.The highest As,Se,and Pb contents were found in W_Py and N_Py.These results indicate the drastic changes in the temperature and fluid mixing during the mineralization.The occurrence of fluctuation and change in temperature and f(O_(2)) was triggered by intermittent pulses of magmatic-hydrothermal fluids,mixing with meteoric water,and water-rock interactions.The sulfur isotopes of all species of pyrite indicated the magmatic source.The change in the f(O_(2)) conditions caused slight differences in the sulfur isotope compositions.Consequently,a metallogenic model was proposed to explain the ore-forming processes.展开更多
Effects of chemical composition and heat treatment on microstructures and mechanical properties of in-situ Mg2Si/Al-Si composites were investigated. It was found that, in the microstructure of an Al-5.7wt% Mg2Si compo...Effects of chemical composition and heat treatment on microstructures and mechanical properties of in-situ Mg2Si/Al-Si composites were investigated. It was found that, in the microstructure of an Al-5.7wt% Mg2Si composite with 8.2wt% extra Si, the binary eutectic Mg2Si locates at the grain boundaries with an undeveloped Chinese script-like morphology, and the primary reAl is formed into a cell structure due to the selective modification effect of the modifiers of mischmetal and Strontium salt; whereas in the composite with a near Al-Mg2Si eutectic composition and little extra Si content, the intercrescence eutectic Mg2Si formed with the binary eutectic a-Al grows into integrated Chinese script- like shape. As Si content increases, the eutectic Mg2Si dendrite becomes coarser in morphology but less in volume fraction. Hardness and tensile strength of the cast Mg2Si/Al-Si composites do not increase with increasing of Mg content, but they are related to the size and morphology of the eutectic and primary Mg2Si phases. Heat treatment with optimal parameters is an effective way to improve the properties of the in-situ composites.展开更多
Heavy oil is an important resource in current petroleum exploitation, and the chemical composition information of heavy oil is crucial for revealing its viscosity-inducing mechanism and solving practical exploitation ...Heavy oil is an important resource in current petroleum exploitation, and the chemical composition information of heavy oil is crucial for revealing its viscosity-inducing mechanism and solving practical exploitation issues. In this study, the techniques of high-temperature gas chromatography and high-resolution mass spectrometry equipped with an electrospray ionization source were applied to reveal the chemical composition of typical heavy oils from western, central, and eastern China. The results indicate that these heavy oils display significant variations in their bulk properties, with initial boiling points all above 200℃. Utilizing pre-treatment and ESI high-resolution mass spectrometry, an analysis of the molecular composition of saturated hydrocarbons, aromatic hydrocarbons, acidic oxygen compounds, sulfur compounds, basic nitrogen compounds, and neutral nitrogen compounds within the heavy oil was conducted. Ultimately, a semi-quantitative analysis of the molecular composition of the heavy oil was achieved by integrating the elemental content. The semi-quantitative analysis results of Shengli-J8 heavy oil and a conventional Shengli crude oil show that Shengli-J8 heavy oil lacks alkanes and low molecular weight aromatic hydrocarbons, which contributes to its high viscosity. Additionally,characteristic molecular sets for different heavy oils were identified based on the semi-quantitative analysis of molecular composition. The semi-quantitative analysis of molecular composition in heavy oils may provide valuable reference data for establishing theoretical models on the viscosity-inducing mechanism in heavy oils and designing viscosity-reducing agents for heavy oil exploitation.展开更多
The growth and nutrients of photosynthetic organisms are significantly influenced by light spectra,yet this relationship is not well-understood in microalgae.Herein,we studied three microalgae species—Chaetoceros sp....The growth and nutrients of photosynthetic organisms are significantly influenced by light spectra,yet this relationship is not well-understood in microalgae.Herein,we studied three microalgae species—Chaetoceros sp.,Isochrysis galbana,and Tetraselmis helgolandica—distinguished by their pigments.We exposed them to seven light spectra,including white(control),red,orange,green,blue,violet,and full spectrum.The results showed distinct responses in the three microalgae to varying light spectra.Optimal growth occurred under blue,violet,and white lights for Chaetoceros sp.,Ⅰ.galbana,and T.helgolandica,respectively,while orange,red,and green lights inhibited growth.Notably,green light significantly increased the protein content in all three microalgae.Carbohydrate and lipid content exhibited species-specific responses:the highest carbohydrate accumulation was achieved for Chaetoceros sp.under red light(73.27±1.45 mg/g),Ⅰ.galbana under orange light(122.89±12.28 mg/g),and T.helgolandica under blue light(43.62±2.79 mg/g).Meanwhile,the highest lipid content was obtained under violet light for Chaetoceros sp.andⅠ.galbana(250.80±7.27 and 320.23±5.75 mg/g,respectively),and under green light for T.helgolandica(255.12±31.19 mg/g).Furthermore,violet light greatly promoted the accumulation of polyunsaturated fatty acids in all three microalgae.Specific pigment compositions also responded to variations in light spectra.For instance,the diadinoxanthin content in Chaetoceros sp.increased significantly under orange light(194.77±13.78μg/g),while chlorophyll-a content inⅠ.galbana increased significantly under violet and blue lights((88.84±33.46)-(141.38±1.64)μg/g),and in T.helgolandica under red,green,and blue lights((1485.04±190.46)-(1886.60±387.42)μg/g).Additionally,Ⅰ.galbana exhibited the highest fucoxanthin,diadinoxanthin,andβ-carotene contents under white light.In conclusion,our results highlight the species-specific impact of light spectra on microalgae growth and nutrients,providing valuable guidance for flexible application of light spectra in microalgal production to enhance yields and target specific nutrients.展开更多
A surface Ti-WC composite was fabricated on CP-Ti by surface friction stirring(SFS)using a pinless WC-Cotool at a processing window of 800−2500 r/min and 8−50 mm/min.At 1600 r/min-50 mm/min,a defect-free compositelaye...A surface Ti-WC composite was fabricated on CP-Ti by surface friction stirring(SFS)using a pinless WC-Cotool at a processing window of 800−2500 r/min and 8−50 mm/min.At 1600 r/min-50 mm/min,a defect-free compositelayer with an average hardness of~HV 1170 is formed.The hardness was increased by WC and TiN reinforcingparticles,dissolved Co atoms in Ti,and the formation of ultrafine grains.WC particles were incorporated into the Tisubstrate owing to the intense frictional interaction/heating at the tool-plate interface(~1000℃),which led to strengthloss and wear of the tool.The Williamson-Hall analysis of the XRD peaks of the SFSed sample confirmed a significantlysmall crystallite size(~100 nm).Wear tests showed that the wear resistance of the composite structure was about 4.5times higher than that of the CP-Ti.Friction analysis revealed a significant reduction in average value and fluctuations ofthe friction coefficient.展开更多
This work aimed, on the one hand, to determine the mineral and phytochemical composition of Carica papaya in order to guarantee the food safety of consumers and on the other hand, to evaluate the acute toxicity of pap...This work aimed, on the one hand, to determine the mineral and phytochemical composition of Carica papaya in order to guarantee the food safety of consumers and on the other hand, to evaluate the acute toxicity of papaya seeds. The papayas were bought at the Mzée market in Lubumbashi and Selembao in Kinshasa. Fruit sampling was done according to the ISO 7002 standard on agricultural and food products;the papayas were firm, mature, and without stains or physical damage. The analysis results of the papaya pulp showed both for the samples from the city of Lubumbashi and for the city province of Kinshasa that it contains respectively 85.87% and 84.46% water, 0.59% and 0.53% ash content. The mineral evaluation of our two samples presented a potassium content of 200 ± 8 mg, magnesium 13.12 ± 3 mg, calcium 22.15 ± 2 mg, sodium 3 mg ± 0.5 for the sample from Lubumbashi and 192.32 ± 8 mg of potassium, 14.458 ± 3 mg of magnesium, 20.58 ± 2 mg of calcium and 3.58 ± 0.5 mg of sodium for the sample from Kinshasa in macroelements. Concerning the trace elements, after analysis, we found zinc content (0.29 ± 0.1 mg and 0.12 ± 0.1 mg), copper (0.02 ± 0.01 mg and 0.14 ± 0.01 mg), and iron (2.22 ± 0.5 mg and 2.04 ± 0.5 mg) respectively for Lubumbashi and Kinshasa. The chemical screening indicates the presence of alkaloids, saponosides, tannins catechics, flavonoids and anthocyanins in the palm wine and ethanolic extract of the seeds of Carica papaya and an absence of cyanogenic glycosides and gallic tannins. With mild toxicity, the seeds of the fruit of Carica papaya L. can be used with moderate risk by the population.展开更多
文摘Europium and terbium coordination polymers of pyridine-3-carboxylic acid were in-situ composed with ethyt methacrylate ( EMA ). With the polymerization of EMA monomer and the formation of europium and terbium coordination polymers of pyridiae- 3-carboxylic acid, the transparent hybrid thick fihns composed of [ Eu( NIC )3 ]n ( [ Tb( NIC)3 ]n ) and poly ethyl mettuwrylate ( PEMA ) have been prepared. The luminescence properties and energy transfer of these polymeric composites were studied with absorption spectra, fluorescent excitation trod emission spectra in detail. All the hybrid thick films composed of terbium coordination polymer show the characteristic strong green emission of terbium ions, which implies the same energy transfer mechanism as the pure complex and the hybrid composite film is a suitable sabstrate for the luminescence of terbium ions. In the range of camposing concentration of luminescent species (0.01,0.025,0.05,0.1 mmol /15 mL EMA ), emission intensities increase with the increasing of corresponding composing concentration and the concentration quenching effect does not take place.
基金National Natural ScienceFoundation of China (grant number: 81973696).
文摘Gualou-Xiebai-Banxia Decoction(GXBD)is a traditional Chinese herbal formula including four traditional Chinese medicines:Gualou(Trichosanthis Fructus,TF),Xiebai(Allii Macrostemonis Bulbus,AMB),Banxia(Pinelliae Rhizoma,PR)and yellow wine.It is a classical therapy for chest stuffiness and pain syndrome and is widely used in the clinical treatment of coronary heart disease.It also shows significant therapeutic effects on pulmonary heart disease,hyperlipidemia,and arrhythmia.This study conducted a literature review and collected information on GXBD from databases such as PubMed,Web of Science,China National Knowledge Infrastructure,and ScienceDirect.The result indicated that the main active ingredients of GXBD are steroids,flavonoids,terpenoids,alkaloids,amino acids,and organic acids.Trigonelline,macrostemonoside and cucurbitacin B can provide reference for its quality control.GXBD may exert therapeutic effects on coronary heart disease through AMPK,PI3K-AKT,oxLDL,VEGF,and NF-κB signal pathways.This review provides a comprehensive analysis and summary of the chemical composition and in vivo metabolism of three traditional Chinese medicines(TF,AMB,and PR),along with an evaluation of the chemical composition,quality control,pharmacological effects,and clinical application of GXBD.Based on these,areas requiring further research on GXBD have been proposed to provide a reference for its further development and new drug research.
基金Supported by Science and Technology Bureau of Quzhou,No.2022079.
文摘BACKGROUND Body composition analysis(BCA)is primarily used in the management of conditions such as obesity and endocrine disorders.However,its potential in providing nutritional guidance for patients with Alzheimer’s disease(AD)remains relatively unexplored.AIM To explore the clinical efficacy of BCA-based dietary nutrition scheme on bone metabolism in AD patients.METHODS This retrospective study included 96 patients with AD complicated by osteoporosis who were admitted to The Third Hospital of Quzhou between January 2023 and December 2024.Based on data from previous similar studies,the patients were randomly assigned to either a routine diet(RD)group(n=48)or a personalized nutrition(PN)group(n=48).The RD group received conventional dietary guidance,while the PN group received individualized diet intervention measures based on human BCA.The intervention period lasted for 12 weeks.Bone mineral density(BMD),body mass index(BMI),muscle mass,mineral content,osteocalcin,25-hydroxyvitamin D,procollagen type I N-terminal propeptide(PINP),beta C-terminal telopeptide of type I collagen(β-CTX),and serum calcium were measured and compared between the two groups before and 12 weeks after the intervention.RESULTS No significant differences were observed between groups in terms of age,sex,height,BMI,or other baseline data(P>0.05).In both groups,BMI did not show significant changes after the intervention(P>0.05),whereas muscle mass and mineral content were significantly increased(P<0.05).After the intervention,BMI in the PN group did not differ significantly from that of the RD group,but muscle mass and mineral content were significantly higher in the PN group(P<0.05).After the intervention,a higher proportion of patients in the PN group had a T score>-1 compared to the RD group(P<0.05).The mini-mental state examination(MMSE)score was similar in both groups before the intervention.However,12 weeks after the intervention,the MMSE score in the PN group was significantly higher than that in the RD group(P<0.05).In both groups,the MMSE score significantly increased 12 weeks post-intervention compared to pre-intervention levels(P<0.05).Before the intervention,the levels of osteocalcin,serum calcium,PINP,β-CTX,and 25-hydroxyvitamin D were not significantly different between the two groups(P>0.05).After 12 weeks of intervention,the PN group exhibited higher levels of osteocalcin,serum calcium,and 25-hydroxyvitamin D,as well as lower levels of PINP andβ-CTX,compared to the RD group(P<0.05).In both groups,osteocalcin,serum calcium,and 25-hydroxyvitamin D levels were significantly higher,while PINP andβ-CTX levels were significantly lower after 12 weeks of intervention compared to baseline(P<0.05).CONCLUSION The human BCA-based dietary nutrition regimen plays a crucial role in improving BMD and bone metabolism,with effects that surpass those of conventional nutrition strategies.The findings of this study provide strong evidence for the nutritional management of AD patients.
基金financially supported by the National Key Research&Development Program of China(Nos.2020YFB2008300,2020YFB2008303)。
文摘Titanium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high modulus.In this study,the TA15-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder metallurgy and casting technique.Microstructural characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were evaluated.Results revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and TiC.However,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like morphology.Microhardness increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature elongation.Conversely,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.
基金supported by the Guangdong Basic and Applied Basic Research Foundation (2020B1515120013,2022B1515120066)National Natural Science Foundation of China (Nos.U2001218, 51875215)+1 种基金Key-Area Research and Development Program of Guangdong Province (2020B090923001)Special Support Foundation of Guangdong Province (No.2019TQ05Z110)。
文摘It has always been challenging work to reconcile the contradiction between the strength and plasticity of titanium materials.Laser powder bed fusion(LPBF) is a convenient method to fabricate innovative composites including those inspired by gradient layered materials.In this work,we used LPBF to selectively prepare Ti N/Ti gradient layered structure(GLSTi)composites by using different N_(2)–Ar ratios during the LPBF process.We systematically investigated the mechanisms of in-situ synthesis Ti N,high strength and ductility of GLSTi composites using microscopic analysis,TEM characterization,and tensile testing with digital image correlation.Besides,a digital correspondence was established between the N_(2) concentration and the volume fraction of LPBF in-situ synthesized Ti N.Our results show that the GLSTi composites exhibit superior mechanical properties compared to pure titanium fabricated by LPBF under pure Ar.Specifically,the tensile strength of GLSTi was more than 1.5times higher than that of LPBF-formed pure titanium,reaching up to 1100 MPa,while maintaining a high elongation at fracture of 17%.GLSTi breaks the bottleneck of high strength but low ductility exhibited by conventional nanoceramic particle-strengthened titanium matrix composites,and the hetero-deformation induced strengthening effect formed by the Ti N/Ti layered structure explained its strength-plasticity balanced principle.The microhardness exhibits a jagged variation of the relatively low hardness of 245 HV0.2 for the pure titanium layer and a high hardness of 408 HV0.2 for the N_(2) in-situ synthesis layer.Our study provides a new concept for the structure-performance digital customization of 3D-printed Ti-based composites.
基金supported by the National Natural Science Foundation of China(No.21676065 and No.52373262)China Postdoctoral Science Foundation(2021MD703944,2022T150782).
文摘Microwave absorbing materials(MAMs)characterized by high absorption efficiency and good environmental tolerance are highly desirable in practical applications.Both silicon carbide and carbon are considered as stable MAMs under some rigorous conditions,while their composites still fail to produce satisfactory microwave absorption performance regardless of the improvements as compared with the individuals.Herein,we have successfully implemented compositional and structural engineering to fabricate hollow Si C/C microspheres with controllable composition.The simultaneous modulation on dielectric properties and impedance matching can be easily achieved as the change in the composition of these composites.The formation of hollow structure not only favors lightweight feature,but also generates considerable contribution to microwave attenuation capacity.With the synergistic effect of composition and structure,the optimized SiC/C composite exhibits excellent performance,whose the strongest reflection loss intensity and broadest effective absorption reach-60.8 dB and 5.1 GHz,respectively,and its microwave absorption properties are actually superior to those of most SiC/C composites in previous studies.In addition,the stability tests of microwave absorption capacity after exposure to harsh conditions and Radar Cross Section simulation data demonstrate that hollow SiC/C microspheres from compositional and structural optimization have a bright prospect in practical applications.
基金supported by the National Natural Science Foundation of China(21972049,21573080)。
文摘Despite the presence of Li F components in the solid electrolyte interphase(SEI)formed on the graphite anode surface by conventional electrolyte,these Li F components primarily exist in an amorphous state,rendering them incapable of effectively inhibiting the exchange reaction between lithium ions and transition metal ions in the electrolyte.Consequently,nearly all lithium ions within the SEI film are replaced by transition metal ions,resulting in an increase in interphacial impedance and a decrease in stability.Herein,we demonstrate that the SEI film,constructed by fluoroethylene carbonate(FEC)additive rich in crystalline Li F,effectively inhibits the undesired Li^(+)/Co^(2+)ion exchange reaction,thereby suppressing the deposition of cobalt compounds and metallic cobalt.Furthermore,the deposited cobalt compounds exhibit enhanced structural stability and reduced catalytic activity with minimal impact on the interphacial stability of the graphite anode.Our findings reveal the crucial influence of SEI film composition and structure on the deposition and hazards associated with transition metal ions,providing valuable guidance for designing next-generation electrolytes.
基金Supported by the“SDF-sweet doctor cultivation”Project of Sinocare Diabetes Foundation,No.2022SD11 and No.2021SD09.
文摘BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relationship between body composition,metabolic syndrome and insulin resistance in T1DM to guide clinical treatment and intervention.AIM To assess body composition(BC)in T1DM patients and evaluate the relationship between BC,metabolic syndrome(MS),and insulin resistance in these indi-viduals.METHODS A total of 101 subjects with T1DM,aged 10 years or older,and with a disease duration of over 1 year were included.Bioelectrical impedance analysis using the Tsinghua-Tongfang BC Analyzer BCA-1B was employed to measure various BC parameters.Clinical and laboratory data were collected,and insulin resistance was calculated using the estimated glucose disposal rate(eGDR).RESULTS MS was diagnosed in 16/101 patients(15.84%),overweight in 16/101 patients(15.84%),obesity in 4/101(3.96%),hypertension in 34/101(33.66%%)and dyslip-idemia in 16/101 patients(15.84%).Visceral fat index(VFI)and trunk fat mass were significantly and negatively correlated with eGDR(both P<0.001).Female patients exhibited higher body fat percentage and visceral fat ratio compared to male patients.Binary logistic regression analysis revealed that significant factors for MS included eGDR[P=0.017,odds ratio(OR)=0.109],VFI(P=0.030,OR=3.529),and a family history of diabetes(P=0.004,OR=0.228).Significant factors for hypertension included eGDR(P<0.001,OR=0.488)and skeletal muscle mass(P=0.003,OR=1.111).Significant factors for dyslipidemia included trunk fat mass(P=0.033,OR=1.202)and eGDR(P=0.037,OR=0.708).CONCLUSION Visceral fat was found to be a superior predictor of MS compared to conventional measures such as body mass index and waist-to-hip ratio in Chinese individuals with T1DM.BC analysis,specifically identifying visceral fat(trunk fat),may play an important role in identifying the increased risk of MS in non-obese patients with T1DM.
基金funded by the National Key R&D Program of China(2022YFC2601100,2021YFD1400100 and 2021YFC2600400)the National Natural Science Foundation of China(42207162)。
文摘Bidens pilosa is recognized as one of the major invasive plants in China.Its invasion has been associated with significant losses in agriculture,forestry,husbandry,and biodiversity.Soil ecosystems play an important role in alien plant invasion.Microorganisms within the soil act as intermediaries between plants and soil ecological functions,playing a role in regulating soil enzyme activities and nutrient dynamics.Understanding the interactions between invasive plants,soil microorganisms,and soil ecological processes is vital for managing and mitigating the impacts of invasive species on the environment.In this study,we conducted a systematic analysis focusing on B.pilosa and Setaria viridis,a common native companion plant in the invaded area.To simulate the invasion process of B.pilosa,we constructed homogeneous plots consisting of B.pilosa and S.viridis grown separately as monocultures,as well as in mixtures.The rhizosphere and bulk soils were collected from the alien plant B.pilosa and the native plant S.viridis.In order to focus on the soil ecological functional mechanisms that contribute to the successful invasion of B.pilosa,we analyzed the effects of B.pilosa on the composition of soil microbial communities and soil ecological functions.The results showed that the biomass of B.pilosa increased by 27.51% and that of S.viridis was significantly reduced by 66.56%.The organic matter contents in the bulk and rhizosphere soils of B.pilosa were approximately 1.30 times those in the native plant soils.The TN and NO_(3)^(-)contents in the rhizosphere soil of B.pilosa were 1.30 to 2.71 times those in the native plant soils.The activities of acid phosphatase,alkaline phosphatase,and urease in the rhizosphere soil of B.pilosa were 1.98-2.25 times higher than in the native plant soils.Using high-throughput sequencing of the16S rRNA gene,we found that B.pilosa altered the composition of the soil microbial community.Specifically,many genera in Actinobacteria and Proteobacteria were enriched in B.pilosa soils.Further correlation analyses verified that these genera had significantly positive relationships with soil nutrients and enzyme activities.Plant biomass,soil p H,and the contents of organic matter,TN,NO_(3)^(-),TP,AP,TK,and AK were the main factors affecting soil microbial communities.This study showed that the invasion of B.pilosa led to significant alterations in the composition of the soil microbial communities.These changes were closely linked to modifications in plant traits as well as soil physical and chemical properties.Some microbial species related to C,N and P cycling were enriched in the soil invaded by B.pilosa.These findings provide additional support for the hypothesis of soil-microbe feedback in the successful invasion of alien plants.They also offer insights into the ecological mechanism by which soil microbes contribute to the successful invasion of B.pilosa.Overall,our research contributes to a better understanding of the complex interactions between invasive plants,soil microbial communities,and ecosystem dynamics.
基金supported the National Natural Science Foundation of China (42022059,41888101)the Strategic Priority Research Program of the Chinese Academy of Sciences,China (Grant No.XDB26020000)+1 种基金the Key Research Program of the Institute of Geology and Geophysics (CAS Grant IGGCAS-201905)the CAS Youth Interdisciplinary Team (JCTD-2021-05).
文摘Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each proxy.Here,we developed a method by which each proxy can be measured in the same sample.First,the sample is polished for ring width meas-urement.After obtaining the ring width data,the sample is cut to form a 1-mm-thick wood plate.The sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray beam.Simultaneously,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,i.e.the density and the element content are obtained.Then,cellulose is isolated from the 1-mm wood plate by removal of lignin,and hemicellulose.After producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)analysis.Based on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.
基金support from the National Natural Science Foundation of China(22073033,21873032,21673087,21903032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technology+1 种基金the Fundamental Research Funds for the Central Universities(2019kfyRCPY116)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)
文摘In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.
基金Funded by the National Torch Plan of China (No. 2005EB031110)the Key Scientific and Technical Innovation Project of Xi’an University of Ar-chitecture and Technology ( No. ZX 0402)
文摘60% white corundum used for aggregate, 5% aluminium powder for fixed additions and 35% various additives for matrix were prepared for specimens 1#,2#,3#. They were mixed uniformly with the suitable resin as a binder and pressed under pressure of 315 ton forging press, then dried at 200℃ for 24 h. Effects of various additives on 1500 ℃×2 h creep properties of Al3CON reinforced corundum composite were researched. The experimenal results show that creep coefficients of specimens 1#,2#,3# at 1500 ℃×2 h are 1.4×10^- 4, -9.4×10^-4, -22.6×10^-4, respectively. Crushing strength of the slide plate added with suitable additive A after fired at 1500 ℃ ×3 h reaches to 225 MPa, the creep rate is positive all the time from 0% to 0.014% at 1500 ℃ for 2 h. The microstructure result analysis shows that reinforced phases of Al3CON fiber composite have been formed after fired with Al powder in coke at high temperatures for specimen 1#, and the strength of the composite is increased. The hot modulus of rupture is up to 59 MPa at 1400 ℃ and the RUL is obviously higher than that at 1700 ℃. Its service life is two times as that of Al2O3-C slide plate when used in the process of pouring steel. The mechanism of creep rate resistance of the composites can be discovered by means of SEM and EDAX analysis. It is concluded that the active Al3CON and Al2O3 multiphases that were formed by N2 in gas, C, Al and Al2O3 inside the matrix of the composites during in-situ reaction,which gives the composites outstanding creep rate resistance for the dense zone resuiting from Al3CON oxidation that inhibits contraction at the high temperature. Besides, the matrix will turn into the multiphase with high refractoriness, N content and its Al3CON reinforced fiber will further increase accordingly. In addition, Al3CON formed by Al2O3 and C, Al in the matrix with N2 in gas will inhibit the creep rate and also greatly improve the creep rate resistance of the composites.
文摘Zeolites ZSM-5 with different Si/Al ratios were in-situ synthesized on the surface ofhoneycomb-shaped cordierite support for the first time. Characterizations of XRD and SEM wereperformed and it has been proved that the zeolite ZSM-5 was grown on the surface of the cordieritehomogeneously. NO decomposition on the Cu exchanged ZSM-5/cordierite monolith catalysts wasalso studied. It was found that the monolith catalysts have a fine initial activity at 673K and GHSVof 10,000h-1. Such method should be a good way to make auto exhaust converter with monolithcatalyst for NOx removal.
文摘This study aimed to discriminate ten Cameroonian cocoa hybrids according to their total fat, fatty acid composition, tocopherol and tocotrienol profiles. Six cocoa clones from the gene banks of the Cameroon Cocoa Development Corporation were used to create hybrids. The determination of fatty acid composition was carried out by using a gas chromatography (GC) apparatus coupled by a flame ion detector (FID). Tocopherol and tocotrienol analysis was performed by upper high-performance liquid chromatography (UHPLC). Information on the impact of the genotype on the cocoa fat composition was provided. The major fatty acids (FA) in fermented samples are stearic (34.57%), palmitic (26.13%), oleic (34.13%) and linoleic (3.16%) acids. (35.05% to 35.6%). SCA12 × ICS40, SCA12 × SNK13, SNK13 × T79/501 have the least hard cocoa butters. Tocopherols analysis showed a predominance of γ-tocopherols (94.64 ± 1.51 to 292.16 ± 3.17 µg∙g<sup>−1</sup>), whereas only a small amount of β and δ-tocopherol (from 0.46 to 2.78 µg∙g<sup>−1</sup> and 0.12 to 5.82 respectively) was observed. No γ-tocotrienol was found in fermented samples. A differentiation in terms of total fat and tocopherol content was observed amongst hybrids with the same mother-clone, suggesting an impact of pollen on these compounds.
基金funded by the National Key Research and Development Program of China (Nos. 2018YFC0603904, 2018YFC0603901)。
文摘In-situ LA-ICP-MS and S isotopes of pyrite from the Baoshan Cu polymetallic deposit were conducted to investigate the ore-forming process and the enrichment mechanism of elements.Three generations of pyrite (Py Ⅰ,Py Ⅱ,and Py Ⅲ) in the skarn-type ores and pyrite in the carbonate-hosted sulfide ores from central,western,and northern(C_Py,W_Py,and N_Py) mining districts are selected for comparison.Compared with Py Ⅰ and Py Ⅲ,the contents of most elements in Py Ⅱ are apparently higher.The As and Se contents are high within a wide range and are decoupled in the growth band of the C_Py.The highest As,Se,and Pb contents were found in W_Py and N_Py.These results indicate the drastic changes in the temperature and fluid mixing during the mineralization.The occurrence of fluctuation and change in temperature and f(O_(2)) was triggered by intermittent pulses of magmatic-hydrothermal fluids,mixing with meteoric water,and water-rock interactions.The sulfur isotopes of all species of pyrite indicated the magmatic source.The change in the f(O_(2)) conditions caused slight differences in the sulfur isotope compositions.Consequently,a metallogenic model was proposed to explain the ore-forming processes.
基金supported by the Jiangxi Provincial Department of Education(No.GJJ08268)
文摘Effects of chemical composition and heat treatment on microstructures and mechanical properties of in-situ Mg2Si/Al-Si composites were investigated. It was found that, in the microstructure of an Al-5.7wt% Mg2Si composite with 8.2wt% extra Si, the binary eutectic Mg2Si locates at the grain boundaries with an undeveloped Chinese script-like morphology, and the primary reAl is formed into a cell structure due to the selective modification effect of the modifiers of mischmetal and Strontium salt; whereas in the composite with a near Al-Mg2Si eutectic composition and little extra Si content, the intercrescence eutectic Mg2Si formed with the binary eutectic a-Al grows into integrated Chinese script- like shape. As Si content increases, the eutectic Mg2Si dendrite becomes coarser in morphology but less in volume fraction. Hardness and tensile strength of the cast Mg2Si/Al-Si composites do not increase with increasing of Mg content, but they are related to the size and morphology of the eutectic and primary Mg2Si phases. Heat treatment with optimal parameters is an effective way to improve the properties of the in-situ composites.
基金supported by the National Key R&D Program of China (2018YFA0702400)the Science Foundation of China University of Petroleum, Beijing (2462023QNXZ017)。
文摘Heavy oil is an important resource in current petroleum exploitation, and the chemical composition information of heavy oil is crucial for revealing its viscosity-inducing mechanism and solving practical exploitation issues. In this study, the techniques of high-temperature gas chromatography and high-resolution mass spectrometry equipped with an electrospray ionization source were applied to reveal the chemical composition of typical heavy oils from western, central, and eastern China. The results indicate that these heavy oils display significant variations in their bulk properties, with initial boiling points all above 200℃. Utilizing pre-treatment and ESI high-resolution mass spectrometry, an analysis of the molecular composition of saturated hydrocarbons, aromatic hydrocarbons, acidic oxygen compounds, sulfur compounds, basic nitrogen compounds, and neutral nitrogen compounds within the heavy oil was conducted. Ultimately, a semi-quantitative analysis of the molecular composition of the heavy oil was achieved by integrating the elemental content. The semi-quantitative analysis results of Shengli-J8 heavy oil and a conventional Shengli crude oil show that Shengli-J8 heavy oil lacks alkanes and low molecular weight aromatic hydrocarbons, which contributes to its high viscosity. Additionally,characteristic molecular sets for different heavy oils were identified based on the semi-quantitative analysis of molecular composition. The semi-quantitative analysis of molecular composition in heavy oils may provide valuable reference data for establishing theoretical models on the viscosity-inducing mechanism in heavy oils and designing viscosity-reducing agents for heavy oil exploitation.
基金Supported by the National Natural Science Foundation of China(No.32102763)the Ningbo Science and Technology Research Projects+3 种基金China(No.2019B10006)the earmarked fund(No.CARS-49)the Ningbo Science and Technology Research ProjectsChina(No.2024Z276)。
文摘The growth and nutrients of photosynthetic organisms are significantly influenced by light spectra,yet this relationship is not well-understood in microalgae.Herein,we studied three microalgae species—Chaetoceros sp.,Isochrysis galbana,and Tetraselmis helgolandica—distinguished by their pigments.We exposed them to seven light spectra,including white(control),red,orange,green,blue,violet,and full spectrum.The results showed distinct responses in the three microalgae to varying light spectra.Optimal growth occurred under blue,violet,and white lights for Chaetoceros sp.,Ⅰ.galbana,and T.helgolandica,respectively,while orange,red,and green lights inhibited growth.Notably,green light significantly increased the protein content in all three microalgae.Carbohydrate and lipid content exhibited species-specific responses:the highest carbohydrate accumulation was achieved for Chaetoceros sp.under red light(73.27±1.45 mg/g),Ⅰ.galbana under orange light(122.89±12.28 mg/g),and T.helgolandica under blue light(43.62±2.79 mg/g).Meanwhile,the highest lipid content was obtained under violet light for Chaetoceros sp.andⅠ.galbana(250.80±7.27 and 320.23±5.75 mg/g,respectively),and under green light for T.helgolandica(255.12±31.19 mg/g).Furthermore,violet light greatly promoted the accumulation of polyunsaturated fatty acids in all three microalgae.Specific pigment compositions also responded to variations in light spectra.For instance,the diadinoxanthin content in Chaetoceros sp.increased significantly under orange light(194.77±13.78μg/g),while chlorophyll-a content inⅠ.galbana increased significantly under violet and blue lights((88.84±33.46)-(141.38±1.64)μg/g),and in T.helgolandica under red,green,and blue lights((1485.04±190.46)-(1886.60±387.42)μg/g).Additionally,Ⅰ.galbana exhibited the highest fucoxanthin,diadinoxanthin,andβ-carotene contents under white light.In conclusion,our results highlight the species-specific impact of light spectra on microalgae growth and nutrients,providing valuable guidance for flexible application of light spectra in microalgal production to enhance yields and target specific nutrients.
文摘A surface Ti-WC composite was fabricated on CP-Ti by surface friction stirring(SFS)using a pinless WC-Cotool at a processing window of 800−2500 r/min and 8−50 mm/min.At 1600 r/min-50 mm/min,a defect-free compositelayer with an average hardness of~HV 1170 is formed.The hardness was increased by WC and TiN reinforcingparticles,dissolved Co atoms in Ti,and the formation of ultrafine grains.WC particles were incorporated into the Tisubstrate owing to the intense frictional interaction/heating at the tool-plate interface(~1000℃),which led to strengthloss and wear of the tool.The Williamson-Hall analysis of the XRD peaks of the SFSed sample confirmed a significantlysmall crystallite size(~100 nm).Wear tests showed that the wear resistance of the composite structure was about 4.5times higher than that of the CP-Ti.Friction analysis revealed a significant reduction in average value and fluctuations ofthe friction coefficient.
文摘This work aimed, on the one hand, to determine the mineral and phytochemical composition of Carica papaya in order to guarantee the food safety of consumers and on the other hand, to evaluate the acute toxicity of papaya seeds. The papayas were bought at the Mzée market in Lubumbashi and Selembao in Kinshasa. Fruit sampling was done according to the ISO 7002 standard on agricultural and food products;the papayas were firm, mature, and without stains or physical damage. The analysis results of the papaya pulp showed both for the samples from the city of Lubumbashi and for the city province of Kinshasa that it contains respectively 85.87% and 84.46% water, 0.59% and 0.53% ash content. The mineral evaluation of our two samples presented a potassium content of 200 ± 8 mg, magnesium 13.12 ± 3 mg, calcium 22.15 ± 2 mg, sodium 3 mg ± 0.5 for the sample from Lubumbashi and 192.32 ± 8 mg of potassium, 14.458 ± 3 mg of magnesium, 20.58 ± 2 mg of calcium and 3.58 ± 0.5 mg of sodium for the sample from Kinshasa in macroelements. Concerning the trace elements, after analysis, we found zinc content (0.29 ± 0.1 mg and 0.12 ± 0.1 mg), copper (0.02 ± 0.01 mg and 0.14 ± 0.01 mg), and iron (2.22 ± 0.5 mg and 2.04 ± 0.5 mg) respectively for Lubumbashi and Kinshasa. The chemical screening indicates the presence of alkaloids, saponosides, tannins catechics, flavonoids and anthocyanins in the palm wine and ethanolic extract of the seeds of Carica papaya and an absence of cyanogenic glycosides and gallic tannins. With mild toxicity, the seeds of the fruit of Carica papaya L. can be used with moderate risk by the population.