Biaxially oriented polypropylene(BOPP)is one of the most commonly used commercial capacitor films,but its upper operating temperature is below 105℃due to the sharply increased electrical conduction loss at high tempe...Biaxially oriented polypropylene(BOPP)is one of the most commonly used commercial capacitor films,but its upper operating temperature is below 105℃due to the sharply increased electrical conduction loss at high temperature.In this study,growing an inorganic nanoscale coating layer onto the BOPP film's surface is proposed to suppress electrical conduction loss at high temperature,as well as increase its upper operating temperature.Four kinds of inorganic coating layers that have different energy band structure and dielectric property are grown onto the both surface of BOPP films,respectively.The effect of inorganic coating layer on the high-temperature energy storage performance has been systematically investigated.The favorable coating layer materials and appropriate thickness enable the BOPP films to have a significant improvement in high-temperature energy storage performance.Specifically,when the aluminum nitride(AIN)acts as a coating layer,the AIN-BOPP-AIN sandwich-structured films possess a discharged energy density of 1.5 J cm^(-3)with an efficiency of 90%at 125℃,accompanying an outstandingly cyclic property.Both the discharged energy density and operation temperature are significantly enhanced,indicating that this efficient and facile method provides an important reference to improve the high-temperature energy storage performance of polymer-based dielectric films.展开更多
Background Fatty liver hemorrhagic syndrome(FLHS),a fatty liver disease in laying hens,poses a grave threat to the layer industry,stemming from its ability to trigger an alarming plummet in egg production and usher in...Background Fatty liver hemorrhagic syndrome(FLHS),a fatty liver disease in laying hens,poses a grave threat to the layer industry,stemming from its ability to trigger an alarming plummet in egg production and usher in acute mortality among laying hens.Increasing evidence suggests that the onset and progression of fatty liver was closely related to mitochondria dysfunction.Sodium butyrate was demonstrated to modulate hepatic lipid metabolism,alle-viate oxidative stress and improve mitochondrial dysfunction in vitro and mice models.Nevertheless,there is limited existing research on coated sodium butyrate(CSB)to prevent FLHS in laying hens,and whether and how CSB exerts the anti-FLHS effect still needs to be explored.In this experiment,the FLHS model was induced by administering a high-energy low-protein(HELP)diet in laying hens.The objective was to investigate the effects of CSB on alleviating FLHS with a focus on the role of CSB in modulating mitochondrial function.Methods A total of 288 healthy 28-week-old Huafeng laying hens were arbitrarily allocated into 4 groups with 6 replicates each,namely,the CON group(normal diet),HELP group(HELP diet),CH500 group(500 mg/kg CSB added to HELP diet)and CH750 group(750 mg/kg CSB added to HELP diet).The duration of the trial encompassed a period of 10 weeks.Results The result revealed that CSB ameliorated the HELP-induced FLHS by improving hepatic steatosis and patho-logical damage,reducing the gene levels of fatty acid synthesis,and promoting the mRNA levels of key enzymes of fatty acid catabolism.CSB reduced oxidative stress induced by the HELP diet,upregulated the activity of GSH-Px and SOD,and decreased the content of MDA and ROS.CSB also mitigated the HELP diet-induced inflammatory response by blocking TNF-α,IL-1β,and F4/80.In addition,dietary CSB supplementation attenuated HELP-induced activation of the mitochondrial unfolded protein response(UPRmt),mitochondrial damage,and decline of ATPase activity.HELP diet decreased the autophagosome formation,and downregulated LC3B but upregulated p62 protein expression,which CSB administration reversed.CSB reduced HELP-induced apoptosis,as indicated by decreases in the Bax/Bcl-2,Caspase-9,Caspase-3,and Cyt C expression levels.Conclusions Dietary CSB could ameliorate HELP diet-induced hepatic dysfunction via modulating mitochondrial dynamics,autophagy,and apoptosis in laying hens.Consequently,CSB,as a feed additive,exhibited the capacity to prevent FLHS by modulating autophagy and lipid metabolism.展开更多
We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and...We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and possesses different transmission conditions.Using the variational method,we obtain the well posedness of the interior transmission problem,which plays an important role in the proof of the discreteness of eigenvalues.Then we achieve the existence of an infinite discrete set of transmission eigenvalues provided that n≡1,where a fourth order differential operator is applied.In the case of n■1,we show the discreteness of the transmission eigenvalues under restrictive assumptions by the analytic Fredholm theory and the T-coercive method.展开更多
Seed coat color affects the appearance and commodity quality of mung beans(Vigna radiata L.).The substances that affect mung bean seed coat color are mainly flavonoids,which have important medicinal value.Mapping the ...Seed coat color affects the appearance and commodity quality of mung beans(Vigna radiata L.).The substances that affect mung bean seed coat color are mainly flavonoids,which have important medicinal value.Mapping the seed coat color gene in mung beans would facilitate the development of new varieties and improve their value.In this study,an F2 mapping population consisting of 546 plants was constructed using Jilv9(black seed coat)and BIS9805(green seed coat).Using bulk segregated analysis(BSA)sequencing and kompetitive allele-specific PCR(KASP)markers,the candidate region related to seed coat color was finally narrowed to 0.66 Mb on chromosome(Chr.)4 and included eight candidate genes.Combined transcriptome and metabolome analyses showed that three of the eight candidate genes(LOC106758748,LOC106758747,and LOC106759075)were differentially expressed,which may have caused the differences in flavonoid metabolite content between Jilv9 and BIS9805.These findings can provide a research basis for cloning the genes related to seed coat color and accelerate molecular markerassisted selection breeding in mung beans.展开更多
Rare-earth silicates are promising environmental barrier coatings(EBCs)that can protect SiC_(f)/Si C_(m)substrates in next-genera tion gas turbine blades.Notably,RE_(2)Si_(2)O_(7)(RE=Yb and Ho)shows potential as an EB...Rare-earth silicates are promising environmental barrier coatings(EBCs)that can protect SiC_(f)/Si C_(m)substrates in next-genera tion gas turbine blades.Notably,RE_(2)Si_(2)O_(7)(RE=Yb and Ho)shows potential as an EBC due to its coefficient of thermal expansion(CTE)compatible with substrates and high resistance to water vapor corrosion.The target operating temperature for next-generation tur bine blades is 1400°C.Corrosion is inevitable during adhesion to molten volcanic ash,and thus,understanding the corrosion behavior o the material is crucial to its reliability.This study investigates the high-temperature corrosion behavior of sintered RE_(2)Si_(2)O_(7)(RE=Yb and Ho).Samples were prepared using a solid-state reaction and hot-press method.They were then exposed to volcanic ash at 1400°C for 224,and 48 h.After 48 h of exposure,volcanic ash did not react with Yb_(2)Si_(2)O_(7)but penetrated its interior,causing damage.Meanwhile Ho_(2)Si_(2)O_(7)was partially dissolved in the molten volcanic ash,forming a reaction zone that prevented volcanic ash melts from penetrating the interior.With increasing heat treatment time,the reaction zone expanded,and the thickness of the acicular apatite grains increased The Ca:Si ratios in the residual volcanic ash were mostly unchanged for Yb_(2)Si_(2)O_(7)but decreased considerably over time for Ho_(2)Si_(2)O_(7).Th Ca in volcanic ash was consumed and formed apatite,indicating that RE^(3+)ions with large ionic radii(Ho>Yb)easily precipitated apatit from the volcanic ash.展开更多
High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of th...High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications.展开更多
Boron has high mass and volume calorific values,but it is difficult to ignite and has low combustion efficiency.This literature review summarizes the strategies that are used to solve the above-mentioned problems,whic...Boron has high mass and volume calorific values,but it is difficult to ignite and has low combustion efficiency.This literature review summarizes the strategies that are used to solve the above-mentioned problems,which include coatings of boron by using fluoride compounds,energetic composites,metal fuels,and metal oxides.Coating techniques include recrystallization,dual-solvent,phase transfer,electrospinning,etc.As one of the effective coating agents,the fluorine compounds can react with the oxide shell of boron powder.In comparison,the energetic composites can effectively improve the flame temperature of boron powder and enhance the evaporation efficiency of oxide film as a condensed product.Metals and metal oxides would react with boron powder to form metal borides with a lower ignition point,which could reduce its ignition temperature.展开更多
The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due t...The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due to their excellent reactivity.Therefore it becomes extremely important to understand their aging and failure process in the environment before using them.Here,the aging and failure process of Al/CuO in 71°C/60%RH were investigated,and showed that CuO nanoparticles negatively catalyze Al nanopowders,resulting in rapid hydration.The anti-aging effect of FAS-17-coated Al nanopowder was also examined.The aging process of Al,Al/CuO,and Al@FAS-17/CuO in high humidity and heat environment were revealed by quasi-in situ SEM and TEM methods.Compared with the aging of pure Al,the Al nanopowder in the nanothermites strongly agglomerated with the CuO nanopowder and hydrated earlier.This may be caused by CuO catalyzed hydration of Al nanopowder.The energy release experiments showed that the performance of Al/CuO decreased rapidly and failed to ignite after 4 h of aging.In contrast,the Al@FAS-17/CuO thermite can achieve long-term stability of up to 60 h in the same environment by simple cladding of FAS-17.It is found that FAS-17 coated Al nanopowder can prevent both particle agglomeration and water erosion,which is an effective means to make nanothermites application in high humidity and heat environment.展开更多
Cobalt sulphides attract much attention as anode materials for Li-ion batteries(LIBs).However,its poor conductivity,low initial column efficiency and large volume changes during cycling have hindered its further devel...Cobalt sulphides attract much attention as anode materials for Li-ion batteries(LIBs).However,its poor conductivity,low initial column efficiency and large volume changes during cycling have hindered its further development.Herein,novel interlaced CoS nanosheets were firstly prepared on Carbon Fiber Cloth(CFC)by two hydrothermal reactions followed with carbon coating via carbonizing dopamine(CoS NS@C/CFC).As a freestanding anode,the nanosheet structure of CoS not only accommodates the volume variation,but also provides a large interface area to proceed the charge transfer reaction.In addition,CFC works as both a three-dimensional skeleton and an active substance which can further improve the areal capacity of the resulting electrode.Furthermore,the coated carbon combined with the CFC work as a 3D conductive network to facilitate the electron conduction.The obtained CoS NS@C/CFC,and the contrast sample prepared with the same procedure but without carbon coating(CoS NS/CFC),are characterized with XRD,SEM,TEM,XPS and electrochemical measurements.The results show that the CoS NS@C/CFC possesses much improved electrochemical performance due to the synergistic effect of nanosheet CoS,the coated carbon and the CFC substrate,exhibiting high initial columbic efficiency(~87%),high areal capacity(2.5 at 0.15 mA cm−2),excellent rate performance(1.6 at 2.73 mA cm−2)and improved cycle stability(87.5%capacity retention after 300 cycles).This work may provide a new route to explore freestanding anodes with high areal specific capacity for LIBs.展开更多
High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium batteries.However,the poor structural stability and severe side reactions at the electrode/electrolyte interface...High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium batteries.However,the poor structural stability and severe side reactions at the electrode/electrolyte interface result in unsatisfactory cycle performance.Herein,the thin layer of two-dimensional(2D)graphitic carbon-nitride(g-C_(3)N_(4))is uniformly coated on the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(denoted as NCM811@CN)using a facile chemical vaporization-assisted synthesis method.As an ideal protective layer,the g-C_(3)N_(4)layer effectively avoids direct contact between the NCM811 cathode and the electrolyte,preventing harmful side reactions and inhibiting secondary crystal cracking.Moreover,the unique nanopore structure and abundant nitrogen vacancy edges in g-C_(3)N_(4)facilitate the adsorption and diffusion of lithium ions,which enhances the lithium deintercalation/intercalation kinetics of the NCM811 cathode.As a result,the NCM811@CN-3wt%cathode exhibits 161.3 mAh g^(−1)and capacity retention of 84.6%at 0.5 C and 55°C after 400 cycles and 95.7 mAh g^(−1)at 10 C,which is greatly superior to the uncoated NCM811(i.e.129.3 mAh g^(−1)and capacity retention of 67.4%at 0.5 C and 55°C after 220 cycles and 28.8 mAh g^(−1)at 10 C).The improved cycle performance of the NCM811@CN-3wt%cathode is also applicable to solid–liquid-hybrid cells composed of PVDF:LLZTO electrolyte membranes,which show 163.8 mAh g^(−1)and the capacity retention of 88.1%at 0.1 C and 30°C after 200 cycles and 95.3 mAh g^(−1)at 1 C.展开更多
A novel type of microencapsulated phase change materials(microPCMs)based on 1-tetradecanol(TD)core and silver-coated poly(melamine-urea-formaldehyde)(MUF)shell was successfully synthesized by in situ polymerization me...A novel type of microencapsulated phase change materials(microPCMs)based on 1-tetradecanol(TD)core and silver-coated poly(melamine-urea-formaldehyde)(MUF)shell was successfully synthesized by in situ polymerization method followed by silver reduction.Fourier-transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy with energy dispersive X-ray spectrometry(SEM/EDS),thermogravimetric analysis(TGA)and differential scanning calorimetry(DSC)were used to characterize the chemical structure,morphology and thermal properties of the as-prepared silver-coated microPCMs.FTIR analysis confirmed the successful encapsulation of TD with MUF wall materials.The SEM and EDS results indicated that the prepared silver-coated MUF microPCMs exhibited uniform spherical shape with a perfect silver outer layer.From XRD analysis,the Ag metal dispersed on the surface of microcapsules presented the form of elementary substance.The deposition weight of silver particles on the microcapsule surface increased with increasing the amount of silver nitrate,as indicated by EDS tests.The DSC results indicated that the melting temperature and the melting latent heat of microPCMs modified with 0.7g of silver nitrate in 150mL aqueous solution were 39.2°C and 126.6J·g^-1,respectively.Supercooling of the microPCMs coated with silver particles was effectively suppressed,compared with that of microPCMs without Ag.Thus,the encapsulation of TD with silver-coated MUF shell developed by this work can be an effective method to prepare the microPCMs with enhanced thermal transfer performance and phase change properties.展开更多
A microwave absorbing sheet with a high complex permeability and a relatively low complex permittivity is obtained by molding of the densely coated flaky carbonyl iron particles(FCIPs)by styrenebutadiene-styrene block...A microwave absorbing sheet with a high complex permeability and a relatively low complex permittivity is obtained by molding of the densely coated flaky carbonyl iron particles(FCIPs)by styrenebutadiene-styrene block copolymer(SBS)in the assistance of coupling agent modification.Direct molding of the core-shell FCIPs without adding extra binder results in a large permeability due to the high filling ratio(55vol%)of absorbents.Importantly,the permittivity is well suppressed by the dense insulate polymer shell on the FCIPs,avoiding the severe impedance mismatch problem of the high filler content microwave absorbing materials.Investigations show that modifying the surface of FCIPs by proper amount of silane coupling agent is critical for the coating quality of the SBS shell,which is verified by resistivity and corrosion current density measurements,and can be interpreted by improved interfacial compatibility between the modified FCIPs and SBS.The obtained microwave absorbing sheet shows a minimum reflection loss of-38.74 dB at 1.57 GHz and has an effective absorption bandwidth from 1.1 to 2.3 GHz at a relatively small thickness of 2 mm.展开更多
The properties of dry-coated paracetamol particles(fast-dissolving model drug)with carnauba wax particles as the coating agent(dissolution retardant)were investigated.Raman mapping technique was used to non-destructiv...The properties of dry-coated paracetamol particles(fast-dissolving model drug)with carnauba wax particles as the coating agent(dissolution retardant)were investigated.Raman mapping technique was used to non-destructively examine the thickness and homogeneity of coated particles.The results showed that the wax existed in two forms on the surface of the paracetamol particles,forming a porous coating layer:i)whole wax particles on the surface of paracetamol and glued together with other wax surface particles,and ii)deformed wax particles spread on the surface.Regardless of the final particle size fraction(between 100 and 800 mm),the coating thickness had high variability,with average thickness of 5.9±4.2 mm.The ability of carnauba wax to decrease the dissolution rate of paracetamol was confirmed by dissolution of powder and tablet formulations.The dissolution was slower for larger coated particles.Tableting further reduced the dissolution rate,clearly indicating the impact of subsequent formulation processes on the final quality of the product.展开更多
Pure Ni and its composites with different percentages of Ni-Cr nano-oxides were coated over carbon steel to assess the coating features and mechanical and corrosion behavior.A nano-oxide composite of Ni-Cr was first s...Pure Ni and its composites with different percentages of Ni-Cr nano-oxides were coated over carbon steel to assess the coating features and mechanical and corrosion behavior.A nano-oxide composite of Ni-Cr was first synthesized through chemical coprecipitation with uniform distribution constituents.Electrodeposition was employed to coat pure Ni and Ni-(Ni-Cr)oxides(10,20,30,40,and 50 g/L)on the steel sheets.Transmission electron microscope and field emission scanning electron microscope were adopted to examine the microstructure of powders and coatings,and X-ray diffraction analysis was employed to study the chemical composition.The microhardness,thickness,and wear resistance of the coatings were assessed,polarization and electrochemical impedance spectroscopy(EIS)tests were conducted to analyze the corrosion behavior,and the corresponding equivalent circuit was developed.Results showed flawless and crack-free coatings for all samples and uniform distribution of nano-oxides in the Ni matrix for the samples of 10-30 g/L.Agglomerated oxides were detected at high concentrations.Maximum microhardness(HV 661),thickness(116μm),and wear resistance of coatings were found at 30 g/L.A three-loop equivalent circuit corresponded satisfactorily to all EIS data.The corrosion resistance increased with the nano-oxide concentration of up to 30 g/L but decreased at 40 g/L.The sample of 50 g/L showed the best corrosion resistance.展开更多
The present work is investigated the in-situ monitoring of local corrosion process of scratched epoxy coated carbon steel in saturated Ca(OH)<sub>2</sub> with and without 3% NaCl using SECM and correlated ...The present work is investigated the in-situ monitoring of local corrosion process of scratched epoxy coated carbon steel in saturated Ca(OH)<sub>2</sub> with and without 3% NaCl using SECM and correlated with EIS. The results obtained from EIS analysis showed that the corrosion resistance of scratched epoxy coated carbon steel decreases in Cl<sup>-</sup> containing solution as the increase in wet/ dry corrosion cycles. This was indicated by decrease in film resistance (R<sub>f</sub>) and charge transfer resistance (R<sub>ct</sub>), while the coated steel maintain the resistance values in saturated Ca(OH)<sub>2</sub>, most of which recovered after drying. The corrosion process was monitored using SECM by setting the tip potential at -0.70 V vs Ag/AgCl, where the consumption of dissolved oxygen occurred at the surface of test sample. The consumption of dissolved oxygen current (I’<sub>oxy-c</sub>) values was increased during the immersion in a solution with 3% NaCl. However, in wet/dry corrosion cycles, I’<sub>oxy-c</sub> was decreased due to the coverage of hydroxides/oxides at scratch area which suppressed the consumption of dissolved O<sub>2</sub>. It was found that the continuous decrease in corrosion was mainly attributed to continuous formation of corrosion products at anodic spots.展开更多
Owing to the popularization of coating technology, physical Vapor Deposition (PVD) coated tools have become indispensable in the cutting process. Additionally, the post-treatment of coated tools applied to industrial ...Owing to the popularization of coating technology, physical Vapor Deposition (PVD) coated tools have become indispensable in the cutting process. Additionally, the post-treatment of coated tools applied to industrial production can efectively enhance the surface quality of coating. To improve the processing performance of coated tools, micro abrasive slurry jet (MASJ) polishing technology is frst applied to the post-treatment of coated tools. Subsequently, the efects of process parameters on the surface quality and cutting thickness of coating are investigated via single-factor experiments. In the experiment, the best surface roughness is obtained by setting the working pressure to 0.4 MPa, particle size to 3 μm, incidence angle to 30°, and abrasive mass concentration to 100 g/L. Based on the results of the single-factor experiments, combination experiments are designed, and three types of coated tools with diferent surface qualities and coating thicknesses are obtained. The MASJ process for the post-treatment of coated tools is investigated based on a tool wear experiment and the efects of cutting parameters on the cutting force and workpiece surface quality of three types of cutting tools. The result indicates that MASJ machining can efectively improve the machining performance of coated tools.展开更多
Silicon-based material is an important anode material for next-generation lithium-ion batteries.In order to overcome its shortcomings,carbon coating is often employed to improve the electrochemical performance.However...Silicon-based material is an important anode material for next-generation lithium-ion batteries.In order to overcome its shortcomings,carbon coating is often employed to improve the electrochemical performance.However,the carbon source,carbon content,and different contact and mixing schemes between carbon sources and silicon are all complex factors and need to be clarified.In this study,nano-silicon is coated by the chemical vapor deposition method using different carbon sources,such as acetylene,methane,propane,and propylene.Carbon content after coating is designed to stay at the same level to reduce the experimental error.Results show the sample with higher conductivity provides higher cycle performance.Propylene is the best choice of the four carbon sources studied in this work.These results indicate that the selection of the carbon source is an important factor that plays a significant role in electrochemical performance.展开更多
A cold method was used to prepare coated sand for application in the selective laser sintering(SLS)process.Tensile strength,loss on ignition,gas evolution,and accuracy of the SLS samples were tested and analyzed,and t...A cold method was used to prepare coated sand for application in the selective laser sintering(SLS)process.Tensile strength,loss on ignition,gas evolution,and accuracy of the SLS samples were tested and analyzed,and the baking process was thoroughly investigated.Compared with coated sand prepared by the hot method,the cold method yields a more uniform and complete resin film on the sand's surface,resulting in enhanced tensile strength and accuracy.Additionally,the cold method requires a lower binder content to meet the same strength requirements,thereby minimizing gas evolution,reducing porosity defects,and ultimately improving casting quality.The coated sand samples prepared through the cold method exhibit superior accuracy,with a size error of within±0.4 mm.In contrast,the coated sand samples prepared by the hot method display a lower accuracy,with an average negative error of 2.1993 mm.The highest tensile strength could be attained by controlling the baking temperature within a suitable range(180-190°C),which can effectively reduce the generation of gas,thus contributing to improved overall performance.展开更多
The carbon-coated ZnO nanospheres materials have been synthesized via a simple hydrothermal method.The effect of carbon content on the microstructure,morphology and electrochemical performance of the materials was inv...The carbon-coated ZnO nanospheres materials have been synthesized via a simple hydrothermal method.The effect of carbon content on the microstructure,morphology and electrochemical performance of the materials was investigated by XRD,Raman spectroscopy,transmission electron microscopy,scanning electron microscopy and electrochemical techniques.Research results show that the spherical ZnO/C material with a carbon cladding content of 10%is very homogeneous and approximately 200 nm in size.The electrochemical performances of the ZnO/C nanospheres as an anode materials are examines.The ZnO/C exhibits better stability than pure ZnO,excellent lithium storage properties as well as improved circulation performance.The Coulomb efficiency of the ZnO/C with 10%carbon coated content reaches 98%.The improvement of electrochemical performance can be attributed to the carbon layer on the ZnO surface.The large volume change of ZnO during the charge-discharge process can be effectively relieved.展开更多
In this study,boron-doped hydroxyapatite(BHT)-loaded alginate/gelatin-based(A/G)hydrogel coating on Ti was fabricated to support bone integration through triggering osteoinduction,vascularization and immunomodulation....In this study,boron-doped hydroxyapatite(BHT)-loaded alginate/gelatin-based(A/G)hydrogel coating on Ti was fabricated to support bone integration through triggering osteoinduction,vascularization and immunomodulation.Initially,highly reproducible,cheap and time-effective BHT was produced,which significantly promoted higher osteogenic and angiogenic maturation,while a mild innate immune response was observed.The immense potential of BHT was evidenced by the production of a gap-filling A/G/BHT interphase on Ti implants to mimic the osseous extracellular matrix to achieve functional bridging and exert control over the course of innate immune response.We initially aminosilanized the implant surface using 3-aminopropyl triethoxysilane,and then coated it with 0.25%w/v alginate with 20 mM 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to allowthe A/G/BHT pre-gel to disperse evenly and covalently attach on the surface.The pre-gel was added with 0.2 M NaCl to homogeneously blend BHT in the structure without inducing ionic crosslinking.Then,the coated implants were freeze-dried and stored.The coated layer demonstrated high cohesive and adhesive strength,and 8-month-long shelf-life at room temperature and normal humidity.The A/G/BHT was able to coat an irregularly shaped Ti implant.Osteoblasts and endothelial cells thrived on the A/G/BHT,and it demonstrated greatly improved osteogenic and angiogenic capacity.Moreover,A/G/BHT maintained macrophage viability and generated an acute increase in immune response that could be resolved rapidly.Finally,A/G/BHT was shown to induce the robust integration of implant in a rabbit femur osteochondral model within 2months.Therefore,we concluded that A/G/BHT coatings could serve as amultifunctional reservoir,promoting the strong and rapid osseointegration of metallic implants.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52277024,U20A20308)Natural Science Foundation of Heilongjiang Province(No.YQ2020E031)+3 种基金China Postdoctoral Science Foundation(Nos.2021T140166,2018M640303)Heilongjiang Province Postdoctoral Science Foundation(No.LBH-Z18099)University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(No.UNPYSCT-2020178)the support from the China Scholarship Council(CSC)
文摘Biaxially oriented polypropylene(BOPP)is one of the most commonly used commercial capacitor films,but its upper operating temperature is below 105℃due to the sharply increased electrical conduction loss at high temperature.In this study,growing an inorganic nanoscale coating layer onto the BOPP film's surface is proposed to suppress electrical conduction loss at high temperature,as well as increase its upper operating temperature.Four kinds of inorganic coating layers that have different energy band structure and dielectric property are grown onto the both surface of BOPP films,respectively.The effect of inorganic coating layer on the high-temperature energy storage performance has been systematically investigated.The favorable coating layer materials and appropriate thickness enable the BOPP films to have a significant improvement in high-temperature energy storage performance.Specifically,when the aluminum nitride(AIN)acts as a coating layer,the AIN-BOPP-AIN sandwich-structured films possess a discharged energy density of 1.5 J cm^(-3)with an efficiency of 90%at 125℃,accompanying an outstandingly cyclic property.Both the discharged energy density and operation temperature are significantly enhanced,indicating that this efficient and facile method provides an important reference to improve the high-temperature energy storage performance of polymer-based dielectric films.
基金This research was supported by the Twinning service plan of the Zhejiang Provincial Team Science and the Science and Technology Develpoment project of Hangzhou(202003A02).
文摘Background Fatty liver hemorrhagic syndrome(FLHS),a fatty liver disease in laying hens,poses a grave threat to the layer industry,stemming from its ability to trigger an alarming plummet in egg production and usher in acute mortality among laying hens.Increasing evidence suggests that the onset and progression of fatty liver was closely related to mitochondria dysfunction.Sodium butyrate was demonstrated to modulate hepatic lipid metabolism,alle-viate oxidative stress and improve mitochondrial dysfunction in vitro and mice models.Nevertheless,there is limited existing research on coated sodium butyrate(CSB)to prevent FLHS in laying hens,and whether and how CSB exerts the anti-FLHS effect still needs to be explored.In this experiment,the FLHS model was induced by administering a high-energy low-protein(HELP)diet in laying hens.The objective was to investigate the effects of CSB on alleviating FLHS with a focus on the role of CSB in modulating mitochondrial function.Methods A total of 288 healthy 28-week-old Huafeng laying hens were arbitrarily allocated into 4 groups with 6 replicates each,namely,the CON group(normal diet),HELP group(HELP diet),CH500 group(500 mg/kg CSB added to HELP diet)and CH750 group(750 mg/kg CSB added to HELP diet).The duration of the trial encompassed a period of 10 weeks.Results The result revealed that CSB ameliorated the HELP-induced FLHS by improving hepatic steatosis and patho-logical damage,reducing the gene levels of fatty acid synthesis,and promoting the mRNA levels of key enzymes of fatty acid catabolism.CSB reduced oxidative stress induced by the HELP diet,upregulated the activity of GSH-Px and SOD,and decreased the content of MDA and ROS.CSB also mitigated the HELP diet-induced inflammatory response by blocking TNF-α,IL-1β,and F4/80.In addition,dietary CSB supplementation attenuated HELP-induced activation of the mitochondrial unfolded protein response(UPRmt),mitochondrial damage,and decline of ATPase activity.HELP diet decreased the autophagosome formation,and downregulated LC3B but upregulated p62 protein expression,which CSB administration reversed.CSB reduced HELP-induced apoptosis,as indicated by decreases in the Bax/Bcl-2,Caspase-9,Caspase-3,and Cyt C expression levels.Conclusions Dietary CSB could ameliorate HELP diet-induced hepatic dysfunction via modulating mitochondrial dynamics,autophagy,and apoptosis in laying hens.Consequently,CSB,as a feed additive,exhibited the capacity to prevent FLHS by modulating autophagy and lipid metabolism.
基金supported by the National Natural Science Foundation of China(11571132,12301542)the Natural Science Foundation of Hubei(2022CFB725)the Natural Science Foundation of Yichang(A23-2-027)。
文摘We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and possesses different transmission conditions.Using the variational method,we obtain the well posedness of the interior transmission problem,which plays an important role in the proof of the discreteness of eigenvalues.Then we achieve the existence of an infinite discrete set of transmission eigenvalues provided that n≡1,where a fourth order differential operator is applied.In the case of n■1,we show the discreteness of the transmission eigenvalues under restrictive assumptions by the analytic Fredholm theory and the T-coercive method.
基金supported by the National Natural Science Foundation of China(32301928)the Basic Research Program of Shanxi Province,China(20210302124504)+3 种基金the China Agriculture Research System of MOF and MARA-Food Legumes(CARS08-G10)the National Laboratory Project of Coarse Grain Germplasm Resources Innovation and Molecular Breeding,China(K462202040-01)the Ph D of Shanxi Agricultural University Scientific Research Start-up Project,China(2021BQ43)the Scientific Research Project of Shanxi Agricultural University,China(YZGC098)。
文摘Seed coat color affects the appearance and commodity quality of mung beans(Vigna radiata L.).The substances that affect mung bean seed coat color are mainly flavonoids,which have important medicinal value.Mapping the seed coat color gene in mung beans would facilitate the development of new varieties and improve their value.In this study,an F2 mapping population consisting of 546 plants was constructed using Jilv9(black seed coat)and BIS9805(green seed coat).Using bulk segregated analysis(BSA)sequencing and kompetitive allele-specific PCR(KASP)markers,the candidate region related to seed coat color was finally narrowed to 0.66 Mb on chromosome(Chr.)4 and included eight candidate genes.Combined transcriptome and metabolome analyses showed that three of the eight candidate genes(LOC106758748,LOC106758747,and LOC106759075)were differentially expressed,which may have caused the differences in flavonoid metabolite content between Jilv9 and BIS9805.These findings can provide a research basis for cloning the genes related to seed coat color and accelerate molecular markerassisted selection breeding in mung beans.
基金supported by JSPS KAKENHI(No.23K19087)“Dynamic Alliance for Open Innovation Bridging Human,Environment and Materials”from the Ministry of Education,Culture,Sports,Science and Technology o f Japan(MEXT).
文摘Rare-earth silicates are promising environmental barrier coatings(EBCs)that can protect SiC_(f)/Si C_(m)substrates in next-genera tion gas turbine blades.Notably,RE_(2)Si_(2)O_(7)(RE=Yb and Ho)shows potential as an EBC due to its coefficient of thermal expansion(CTE)compatible with substrates and high resistance to water vapor corrosion.The target operating temperature for next-generation tur bine blades is 1400°C.Corrosion is inevitable during adhesion to molten volcanic ash,and thus,understanding the corrosion behavior o the material is crucial to its reliability.This study investigates the high-temperature corrosion behavior of sintered RE_(2)Si_(2)O_(7)(RE=Yb and Ho).Samples were prepared using a solid-state reaction and hot-press method.They were then exposed to volcanic ash at 1400°C for 224,and 48 h.After 48 h of exposure,volcanic ash did not react with Yb_(2)Si_(2)O_(7)but penetrated its interior,causing damage.Meanwhile Ho_(2)Si_(2)O_(7)was partially dissolved in the molten volcanic ash,forming a reaction zone that prevented volcanic ash melts from penetrating the interior.With increasing heat treatment time,the reaction zone expanded,and the thickness of the acicular apatite grains increased The Ca:Si ratios in the residual volcanic ash were mostly unchanged for Yb_(2)Si_(2)O_(7)but decreased considerably over time for Ho_(2)Si_(2)O_(7).Th Ca in volcanic ash was consumed and formed apatite,indicating that RE^(3+)ions with large ionic radii(Ho>Yb)easily precipitated apatit from the volcanic ash.
基金Project supported by the National Natural Science Foundation of China(Nos.12302278,U2241267,12172155,and 11932008)the Fundamental Research Funds for the Central Universities of China(No.lzujbky-2022-48)the Natural Science Foundation of Gansu Province of China(No.24JRRA473)。
文摘High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications.
基金funded by Shaanxi Provincial Key Research and Development Program of China(Grant No.2021ZDLGY11)partially supported by NSAF Project of China(Grant No.U2030202)。
文摘Boron has high mass and volume calorific values,but it is difficult to ignite and has low combustion efficiency.This literature review summarizes the strategies that are used to solve the above-mentioned problems,which include coatings of boron by using fluoride compounds,energetic composites,metal fuels,and metal oxides.Coating techniques include recrystallization,dual-solvent,phase transfer,electrospinning,etc.As one of the effective coating agents,the fluorine compounds can react with the oxide shell of boron powder.In comparison,the energetic composites can effectively improve the flame temperature of boron powder and enhance the evaporation efficiency of oxide film as a condensed product.Metals and metal oxides would react with boron powder to form metal borides with a lower ignition point,which could reduce its ignition temperature.
基金supported by the National Natural Science Foundation of China(Grant No.22275092)。
文摘The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due to their excellent reactivity.Therefore it becomes extremely important to understand their aging and failure process in the environment before using them.Here,the aging and failure process of Al/CuO in 71°C/60%RH were investigated,and showed that CuO nanoparticles negatively catalyze Al nanopowders,resulting in rapid hydration.The anti-aging effect of FAS-17-coated Al nanopowder was also examined.The aging process of Al,Al/CuO,and Al@FAS-17/CuO in high humidity and heat environment were revealed by quasi-in situ SEM and TEM methods.Compared with the aging of pure Al,the Al nanopowder in the nanothermites strongly agglomerated with the CuO nanopowder and hydrated earlier.This may be caused by CuO catalyzed hydration of Al nanopowder.The energy release experiments showed that the performance of Al/CuO decreased rapidly and failed to ignite after 4 h of aging.In contrast,the Al@FAS-17/CuO thermite can achieve long-term stability of up to 60 h in the same environment by simple cladding of FAS-17.It is found that FAS-17 coated Al nanopowder can prevent both particle agglomeration and water erosion,which is an effective means to make nanothermites application in high humidity and heat environment.
基金supported by the National Natural Science Foundation of China (Grant Nos.21573109,21206069)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).
文摘Cobalt sulphides attract much attention as anode materials for Li-ion batteries(LIBs).However,its poor conductivity,low initial column efficiency and large volume changes during cycling have hindered its further development.Herein,novel interlaced CoS nanosheets were firstly prepared on Carbon Fiber Cloth(CFC)by two hydrothermal reactions followed with carbon coating via carbonizing dopamine(CoS NS@C/CFC).As a freestanding anode,the nanosheet structure of CoS not only accommodates the volume variation,but also provides a large interface area to proceed the charge transfer reaction.In addition,CFC works as both a three-dimensional skeleton and an active substance which can further improve the areal capacity of the resulting electrode.Furthermore,the coated carbon combined with the CFC work as a 3D conductive network to facilitate the electron conduction.The obtained CoS NS@C/CFC,and the contrast sample prepared with the same procedure but without carbon coating(CoS NS/CFC),are characterized with XRD,SEM,TEM,XPS and electrochemical measurements.The results show that the CoS NS@C/CFC possesses much improved electrochemical performance due to the synergistic effect of nanosheet CoS,the coated carbon and the CFC substrate,exhibiting high initial columbic efficiency(~87%),high areal capacity(2.5 at 0.15 mA cm−2),excellent rate performance(1.6 at 2.73 mA cm−2)and improved cycle stability(87.5%capacity retention after 300 cycles).This work may provide a new route to explore freestanding anodes with high areal specific capacity for LIBs.
基金supported by the National Key R&D Program of China(Grant No.2023YFB2503900)the National Natural Science Foundation of China(Grant No.52372203)+1 种基金the National Natural Science Foundation of China(Grant No.52202259)the Shandong Province Natural Science Foundation(ZR2022QE093).
文摘High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium batteries.However,the poor structural stability and severe side reactions at the electrode/electrolyte interface result in unsatisfactory cycle performance.Herein,the thin layer of two-dimensional(2D)graphitic carbon-nitride(g-C_(3)N_(4))is uniformly coated on the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(denoted as NCM811@CN)using a facile chemical vaporization-assisted synthesis method.As an ideal protective layer,the g-C_(3)N_(4)layer effectively avoids direct contact between the NCM811 cathode and the electrolyte,preventing harmful side reactions and inhibiting secondary crystal cracking.Moreover,the unique nanopore structure and abundant nitrogen vacancy edges in g-C_(3)N_(4)facilitate the adsorption and diffusion of lithium ions,which enhances the lithium deintercalation/intercalation kinetics of the NCM811 cathode.As a result,the NCM811@CN-3wt%cathode exhibits 161.3 mAh g^(−1)and capacity retention of 84.6%at 0.5 C and 55°C after 400 cycles and 95.7 mAh g^(−1)at 10 C,which is greatly superior to the uncoated NCM811(i.e.129.3 mAh g^(−1)and capacity retention of 67.4%at 0.5 C and 55°C after 220 cycles and 28.8 mAh g^(−1)at 10 C).The improved cycle performance of the NCM811@CN-3wt%cathode is also applicable to solid–liquid-hybrid cells composed of PVDF:LLZTO electrolyte membranes,which show 163.8 mAh g^(−1)and the capacity retention of 88.1%at 0.1 C and 30°C after 200 cycles and 95.3 mAh g^(−1)at 1 C.
基金the Opening Project of Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education(Jianghan University)(No.JDGD-201604)。
文摘A novel type of microencapsulated phase change materials(microPCMs)based on 1-tetradecanol(TD)core and silver-coated poly(melamine-urea-formaldehyde)(MUF)shell was successfully synthesized by in situ polymerization method followed by silver reduction.Fourier-transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy with energy dispersive X-ray spectrometry(SEM/EDS),thermogravimetric analysis(TGA)and differential scanning calorimetry(DSC)were used to characterize the chemical structure,morphology and thermal properties of the as-prepared silver-coated microPCMs.FTIR analysis confirmed the successful encapsulation of TD with MUF wall materials.The SEM and EDS results indicated that the prepared silver-coated MUF microPCMs exhibited uniform spherical shape with a perfect silver outer layer.From XRD analysis,the Ag metal dispersed on the surface of microcapsules presented the form of elementary substance.The deposition weight of silver particles on the microcapsule surface increased with increasing the amount of silver nitrate,as indicated by EDS tests.The DSC results indicated that the melting temperature and the melting latent heat of microPCMs modified with 0.7g of silver nitrate in 150mL aqueous solution were 39.2°C and 126.6J·g^-1,respectively.Supercooling of the microPCMs coated with silver particles was effectively suppressed,compared with that of microPCMs without Ag.Thus,the encapsulation of TD with silver-coated MUF shell developed by this work can be an effective method to prepare the microPCMs with enhanced thermal transfer performance and phase change properties.
基金Funded by the Young Top-notch Talent Cultivation Program of Hubei Provincethe National Natural Science Foundation of China(Nos.52071239,51521001)Fundamental Research Funds for the Central Universities(Nos.WUT:2021IVA116 and WUT:2021CG015)。
文摘A microwave absorbing sheet with a high complex permeability and a relatively low complex permittivity is obtained by molding of the densely coated flaky carbonyl iron particles(FCIPs)by styrenebutadiene-styrene block copolymer(SBS)in the assistance of coupling agent modification.Direct molding of the core-shell FCIPs without adding extra binder results in a large permeability due to the high filling ratio(55vol%)of absorbents.Importantly,the permittivity is well suppressed by the dense insulate polymer shell on the FCIPs,avoiding the severe impedance mismatch problem of the high filler content microwave absorbing materials.Investigations show that modifying the surface of FCIPs by proper amount of silane coupling agent is critical for the coating quality of the SBS shell,which is verified by resistivity and corrosion current density measurements,and can be interpreted by improved interfacial compatibility between the modified FCIPs and SBS.The obtained microwave absorbing sheet shows a minimum reflection loss of-38.74 dB at 1.57 GHz and has an effective absorption bandwidth from 1.1 to 2.3 GHz at a relatively small thickness of 2 mm.
基金supported by specific university research(Grant No.:A1_FCHI_2022_006).
文摘The properties of dry-coated paracetamol particles(fast-dissolving model drug)with carnauba wax particles as the coating agent(dissolution retardant)were investigated.Raman mapping technique was used to non-destructively examine the thickness and homogeneity of coated particles.The results showed that the wax existed in two forms on the surface of the paracetamol particles,forming a porous coating layer:i)whole wax particles on the surface of paracetamol and glued together with other wax surface particles,and ii)deformed wax particles spread on the surface.Regardless of the final particle size fraction(between 100 and 800 mm),the coating thickness had high variability,with average thickness of 5.9±4.2 mm.The ability of carnauba wax to decrease the dissolution rate of paracetamol was confirmed by dissolution of powder and tablet formulations.The dissolution was slower for larger coated particles.Tableting further reduced the dissolution rate,clearly indicating the impact of subsequent formulation processes on the final quality of the product.
文摘Pure Ni and its composites with different percentages of Ni-Cr nano-oxides were coated over carbon steel to assess the coating features and mechanical and corrosion behavior.A nano-oxide composite of Ni-Cr was first synthesized through chemical coprecipitation with uniform distribution constituents.Electrodeposition was employed to coat pure Ni and Ni-(Ni-Cr)oxides(10,20,30,40,and 50 g/L)on the steel sheets.Transmission electron microscope and field emission scanning electron microscope were adopted to examine the microstructure of powders and coatings,and X-ray diffraction analysis was employed to study the chemical composition.The microhardness,thickness,and wear resistance of the coatings were assessed,polarization and electrochemical impedance spectroscopy(EIS)tests were conducted to analyze the corrosion behavior,and the corresponding equivalent circuit was developed.Results showed flawless and crack-free coatings for all samples and uniform distribution of nano-oxides in the Ni matrix for the samples of 10-30 g/L.Agglomerated oxides were detected at high concentrations.Maximum microhardness(HV 661),thickness(116μm),and wear resistance of coatings were found at 30 g/L.A three-loop equivalent circuit corresponded satisfactorily to all EIS data.The corrosion resistance increased with the nano-oxide concentration of up to 30 g/L but decreased at 40 g/L.The sample of 50 g/L showed the best corrosion resistance.
文摘The present work is investigated the in-situ monitoring of local corrosion process of scratched epoxy coated carbon steel in saturated Ca(OH)<sub>2</sub> with and without 3% NaCl using SECM and correlated with EIS. The results obtained from EIS analysis showed that the corrosion resistance of scratched epoxy coated carbon steel decreases in Cl<sup>-</sup> containing solution as the increase in wet/ dry corrosion cycles. This was indicated by decrease in film resistance (R<sub>f</sub>) and charge transfer resistance (R<sub>ct</sub>), while the coated steel maintain the resistance values in saturated Ca(OH)<sub>2</sub>, most of which recovered after drying. The corrosion process was monitored using SECM by setting the tip potential at -0.70 V vs Ag/AgCl, where the consumption of dissolved oxygen occurred at the surface of test sample. The consumption of dissolved oxygen current (I’<sub>oxy-c</sub>) values was increased during the immersion in a solution with 3% NaCl. However, in wet/dry corrosion cycles, I’<sub>oxy-c</sub> was decreased due to the coverage of hydroxides/oxides at scratch area which suppressed the consumption of dissolved O<sub>2</sub>. It was found that the continuous decrease in corrosion was mainly attributed to continuous formation of corrosion products at anodic spots.
基金Supported by National Natural Science Foundation of China(Grant No.51735003)Research Start-up Fee for Doctoral Personnel of Binzhou University of China(Grant No.2019Y12)Key Program of NSFC-Guangdong Joint Fund of China(Grant No.U1201245).
文摘Owing to the popularization of coating technology, physical Vapor Deposition (PVD) coated tools have become indispensable in the cutting process. Additionally, the post-treatment of coated tools applied to industrial production can efectively enhance the surface quality of coating. To improve the processing performance of coated tools, micro abrasive slurry jet (MASJ) polishing technology is frst applied to the post-treatment of coated tools. Subsequently, the efects of process parameters on the surface quality and cutting thickness of coating are investigated via single-factor experiments. In the experiment, the best surface roughness is obtained by setting the working pressure to 0.4 MPa, particle size to 3 μm, incidence angle to 30°, and abrasive mass concentration to 100 g/L. Based on the results of the single-factor experiments, combination experiments are designed, and three types of coated tools with diferent surface qualities and coating thicknesses are obtained. The MASJ process for the post-treatment of coated tools is investigated based on a tool wear experiment and the efects of cutting parameters on the cutting force and workpiece surface quality of three types of cutting tools. The result indicates that MASJ machining can efectively improve the machining performance of coated tools.
基金Project supported by Beijing Natural Science Foundation(Grant No.2182065)the National Natural Science Foundation of China(Grant No.11922202)。
文摘Silicon-based material is an important anode material for next-generation lithium-ion batteries.In order to overcome its shortcomings,carbon coating is often employed to improve the electrochemical performance.However,the carbon source,carbon content,and different contact and mixing schemes between carbon sources and silicon are all complex factors and need to be clarified.In this study,nano-silicon is coated by the chemical vapor deposition method using different carbon sources,such as acetylene,methane,propane,and propylene.Carbon content after coating is designed to stay at the same level to reduce the experimental error.Results show the sample with higher conductivity provides higher cycle performance.Propylene is the best choice of the four carbon sources studied in this work.These results indicate that the selection of the carbon source is an important factor that plays a significant role in electrochemical performance.
基金This work was financially supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U1808216)the Shanxi Provincial Key Research and Development Project(2022ZDYF072).
文摘A cold method was used to prepare coated sand for application in the selective laser sintering(SLS)process.Tensile strength,loss on ignition,gas evolution,and accuracy of the SLS samples were tested and analyzed,and the baking process was thoroughly investigated.Compared with coated sand prepared by the hot method,the cold method yields a more uniform and complete resin film on the sand's surface,resulting in enhanced tensile strength and accuracy.Additionally,the cold method requires a lower binder content to meet the same strength requirements,thereby minimizing gas evolution,reducing porosity defects,and ultimately improving casting quality.The coated sand samples prepared through the cold method exhibit superior accuracy,with a size error of within±0.4 mm.In contrast,the coated sand samples prepared by the hot method display a lower accuracy,with an average negative error of 2.1993 mm.The highest tensile strength could be attained by controlling the baking temperature within a suitable range(180-190°C),which can effectively reduce the generation of gas,thus contributing to improved overall performance.
基金Funded by the Key Research Projects in Gansu Province(No.17YF1GA020)。
文摘The carbon-coated ZnO nanospheres materials have been synthesized via a simple hydrothermal method.The effect of carbon content on the microstructure,morphology and electrochemical performance of the materials was investigated by XRD,Raman spectroscopy,transmission electron microscopy,scanning electron microscopy and electrochemical techniques.Research results show that the spherical ZnO/C material with a carbon cladding content of 10%is very homogeneous and approximately 200 nm in size.The electrochemical performances of the ZnO/C nanospheres as an anode materials are examines.The ZnO/C exhibits better stability than pure ZnO,excellent lithium storage properties as well as improved circulation performance.The Coulomb efficiency of the ZnO/C with 10%carbon coated content reaches 98%.The improvement of electrochemical performance can be attributed to the carbon layer on the ZnO surface.The large volume change of ZnO during the charge-discharge process can be effectively relieved.
基金Acknowledgements Authors would like to thank Center of Excellence in Biomaterials and Tissue Engineering(BIOMATEN)for the support provided.Authors also acknowledge financial support provided by National Boron Institute(BOREN,Grant No:2018-31-07-25-001).
文摘In this study,boron-doped hydroxyapatite(BHT)-loaded alginate/gelatin-based(A/G)hydrogel coating on Ti was fabricated to support bone integration through triggering osteoinduction,vascularization and immunomodulation.Initially,highly reproducible,cheap and time-effective BHT was produced,which significantly promoted higher osteogenic and angiogenic maturation,while a mild innate immune response was observed.The immense potential of BHT was evidenced by the production of a gap-filling A/G/BHT interphase on Ti implants to mimic the osseous extracellular matrix to achieve functional bridging and exert control over the course of innate immune response.We initially aminosilanized the implant surface using 3-aminopropyl triethoxysilane,and then coated it with 0.25%w/v alginate with 20 mM 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide to allowthe A/G/BHT pre-gel to disperse evenly and covalently attach on the surface.The pre-gel was added with 0.2 M NaCl to homogeneously blend BHT in the structure without inducing ionic crosslinking.Then,the coated implants were freeze-dried and stored.The coated layer demonstrated high cohesive and adhesive strength,and 8-month-long shelf-life at room temperature and normal humidity.The A/G/BHT was able to coat an irregularly shaped Ti implant.Osteoblasts and endothelial cells thrived on the A/G/BHT,and it demonstrated greatly improved osteogenic and angiogenic capacity.Moreover,A/G/BHT maintained macrophage viability and generated an acute increase in immune response that could be resolved rapidly.Finally,A/G/BHT was shown to induce the robust integration of implant in a rabbit femur osteochondral model within 2months.Therefore,we concluded that A/G/BHT coatings could serve as amultifunctional reservoir,promoting the strong and rapid osseointegration of metallic implants.