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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 161-182页

作者： shen liu Xieping HUANG Xiangzhen {2. Qin FANG Center for Hypergravity Experiment and Interdisciplinary Research Zhejiang UniversityHangzhou310058China Institute of Geotechnical Engineering Zhejiang UniversityHangzhou310058China State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjing210007China

This paper presents a numerical study to improve the understanding of the complex subject of penetration and perforation of concrete targets impacted by low-velocity *** main focus is on the damage mechanisms and the major factors that account for the target resistance of the *** improved continuous surface cap model recently proposed was *** model was first equipped with element erosion criteria and was adequately validated by comparisons with ballistic *** numerical simulations were carried out where the individual influence of tensile,shear,and volumetric behaviors(pore collapse)of a concrete target on its ballistic performance was *** demonstrated that cratering on the front face and scabbing on the rear face of the concrete target were mainly dominated by its tensile *** major target resistance came from the second tunneling stage which was primarily governed by the shear and volumetric behaviors of the ***,this study captured the pore collapse-induced damage phenomenon during the high-pressure tunneling stage,which has been extensively reported in experiments but has usually been neglected in previous numerical investigations.

关键词： Penetration Perforation Damage mechanism Target resistance Projectile impact Pore collapse

Controllable fabrication of FeCoS_(4) nanoparticles/S-doped bowl-shaped hollow carbon as efficient lithium storage anode

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Chinese Journal of Chemical Engineering 2024年第3期67卷 78-88页

作者： ming Zhou Mengrong Wu Haiwei Yu Xiangjun Zheng Kuan shen Xingmei Guo Yuanjun {2. Fu Cao Hongxing Gu Qinghong {3. Junhao Zhang School of Environmental and Chemical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Jiangsu Hengshen Co. LtdZhenjiang 212314China School of the Environment and Safety Engineering Jiangsu UniversityZhenjiang 212013China

To address the low conductivity and easy agglomeration of transition metal sulfide nanoparticles,FeCoS_(4) nanoparticles embedded in S-doped hollow carbon(FeCoS_(4)@S-HC)composites were successfully fabricated through a combination of hydrothermal processes and sulfidation *** unique bowlshaped FeCoS_(4)/S-HC composites exhibit excellent structural stability with a high specific surface area of 3.3.7 m^(2.·g^(-1) and a pore volume of 0.93.cm^(3.·g^(-1).When applied as anode material for lithium-ion batteries,the FeCoS_(4)@S-HC anode exhibits efficient lithium storage with high reversible specific capacity(970.2.mA·h·g^(-1) at 100 mA·g^(-1))and enhanced cycling stability(574 mA·h·g^(-1) at 0.2.A·g^(-1) after 3.0 cycles,a capacity retention of 84%).The excellent lithium storage is attributed to the fact that the bimetallic FeCoS_(4) nanoparticles with abundant active sites can accelerate the electrochemical reaction kinetics,and the bowl-shaped S-HC structure can provide a stable mechanical structure to suppress volume expansion.

关键词： Bimetallic sulfides Bowl-shaped hollow carbon S doping Buffering volume expand Lithium-ion batteries

Time-periodic solutions of the Einstein's field equations II:geometric singularities

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Science china mathematics 2010年第6期53卷 1507-1520页

作者： kong dexing1,liu kefeng2.& shen ming3.1department of mathematics,Zhejiang University,{2.,{3. 2.4} of mathematics,University of California at Los Angeles,CA 90095,USA 3.enter of Mathematical Sciences,Zhejiang University,{2.,{3. 1. department of mathematics Zhejiang University Hangzhou 310027 China2. Department of Mathematics University of California at Los Angeles Los Angeles CA 90095 USA3. Center of Mathematical Sciences Zhejiang University Hangzhou 310027 China

In this paper,we construct several kinds of new time-periodic solutions of the vacuum Einstein's field equations whose Riemann curvature tensors vanish,keep finite or take the infinity at some points in these space-times,*** singularities of these new time-periodic solutions are investigated and some new physical phenomena are discovered.

关键词： Einstein’s field equations time-periodic solution Riemann curvature tensor singularity event horizon

Matrine-loaded self-adhesive swelling microneedle for inflammation regulation to improve eczema treatment

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Marine Life Science & Technology 2024年第3期6卷 535-546页

作者： Jiale shen Jiarui Wang Meng Wu Yan Shi Minhyeock Lee Zhiguo Wang ming {2. College of Marine Life Sciences Ocean University of ChinaQingdao 266003China department of Burn and Plastic Surgery the Affiliated Hospital of Qingdao UniversityQingdao UniversityQingdao 266021China department of Biotechnology College of Life Sciences and BiotechnologyKorea UniversitySeoul 02841Republic of Korea

Eczema is a common chronic dermatological *** treatments exhibit limited efficacy due to fast drug release resulting in short-term *** of a new treatment strategy that enables sustained drug release and longterm maintenance on the skin surface is necessary.A self-adhesive swelling microneedle patch(SDSMNs)was designed and constructed using a two-step casting *** adhesive substrate was prepared by blending gelatin and dopamine via oxidation of NaIO4,so it could adhere onto the skin surface as well as withstand repeated bending movement without *** swelling needles were fabricated using polyvinyl alcohol(PVA)and polyvinylpyrrolidone(PVP),which could swell by absorbing interstitial fluid and release the drug in a controlled *** also showed desirable antibacterial activities toward *** and *** adhesive microneedles loaded with matrine(MAT-SDSMNs),an antiinflammatory Chinese medicine,dramatically relieved eczema symptoms through IL-17 mediated inflammation *** use of MAT-SDSMNs significantly decreased the infiltration of inflammation cells and level of inflammatory cytokines,reduced the skin thickness,and increased collagen deposition fraction compared with conventional ointment or subcutaneous *** results suggested that MAT-SDSMNs can improve eczema treatment by regulating the local inflammatory microenvironment,providing a simple,self-administered sustainable strategy for eczema treatment.

关键词： Self-adhesive swelling microneedle Eczema Matrine Inflammation regulation

Global existence of smooth solutions to two-dimensional compressible isentropic Euler equations for Chaplygin gases

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Science china mathematics 2010年第3期53卷 719-738页

作者： kong dexing 1 , {2. {3. 2.& WANG YuZhu 3. 1 department of mathematics, Zhejiang University, hangzhou 3.002., china 2.department of mathematics, University of California at Los Angeles, CA 90095, USA 3.department of mathematics, Shanghai Jiao Tong University, Shanghai 2.02.8, china 1. department of mathematics Zhejiang University Hangzhou 310027 China2. Department of Mathematics University of California at Los Angeles Los Angeles CA 90095 USA3. Department of Mathematics Shanghai Jiao Tong University Shanghai 200248 China

In this paper we investigate the two-dimensional compressible isentropic Euler equations for Chaplygin gases. Under the assumption that the initial data is close to a constant state and the vorticity of the initial velocity vanishes, we prove the global existence of the smooth solution to the Cauchy problem for twodimensional flow of Chaplygin gases.

关键词： Chaplygin gases compressible Euler equations irrotational flow null condition Cauchy problem smooth solution

Improving surface integrity of micro-holes in ECDM using ultrahigh-speed rotary of tool cathode and non-water-based electrolyte

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Chinese Journal of Aeronautics 2024年第5期37卷 506-519页

作者： Jiwen shen Weijing kong Zhengyang XU Yongbin ZENG Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

The surface integrity of metal micro-hole structures produced by electrochemical discharge machining is unsatisfactory owing to the insufficient reaction area and strength of electrolysis action.A novel ultrahigh-speed Rotary Electrochemical Discharge Machining(R-ECDM)using non-water-based electrolyte is proposed to improve surface integrity by changing the breakdown medium of spark discharge and increasing the reaction area and strength of electrolysis.A mathematical model was developed to establish the relationship between rotational speed and forces acting on the *** on the magnitude of forces,controlling rotational speed changed the behavior and departure radius of bubbles on the cathode ***-speed photographs validate that,in the mathematical model,the number and departure radius of bubbles on the cathode surface gradually decrease with the increase of rotational *** experimental results show that the roughness(Ra)of the micro-hole sidewall decreases from 2.54μm to 0.2.μm when the rotational speed increases from 500 r/min to 40000 r/*** length loss and wear ratio of the cathode are only 9.75μm and 6.5%,***,the micro-holes array with recast-free and surface roughness of 0.2.μm is fabricated,demonstrating that the proposed approach contributes to improving surface integrity of metal micro-holes.

关键词： Electrochemical discharge machining Micro-holes Recast layer Ultrahigh-speed rotary Bubbles Force analysis Non-water-based solution

Which Neighborhoods Have Easier Access to Online Home Delivery Services?A Spatiotemporal Accessibility Analysis in Nanjing,china

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Chinese Geographical Science 2024年第4期34卷 722-738页

作者： kong Yu ZHEN Feng ZHANG Shanqi shen Lizhen School of Architecture and Urban Planning Nanjing UniversityNanjing 210093China Provincial Engineering Research Center of Smart City Planning and Digital Governance Nanjing 210093China

The rise in online home delivery services(OHDS)has had a significant impact on how urban services are supplied and used in recent *** on the spatial accessibility of OHDS are emerging,but few is known about the temporal dimension of OHDS accessibility as well as the geographic and socioeconomic differences in the spatiotemporal accessibility of *** study measures the spatiotemporal accessibility of four types of OHDS,namely leisure,fresh and convenient,medical,and catering *** geographic and socioeconomic disparities in the spatiotemporal accessibility of these four types of OHDS are then identified using spatial statistical methods and the Kruskal-Wallis test(K-W test).The case study in Nanjing,china,suggests that:1)spatiotemporal accessibility better reflects the temporal variation of OHDS accessibility and avoids overestimation of OHDS accessibility when only considering its spatial dimension.2.The spatiotemporal accessibility of OHDS varies geographically and *** located in the main city or neighborhoods with higher housing prices,higher population density,and higher point of interest(POI)mix have better OHDS spatiotemporal *** study contributes to the understanding of OHDS accessibility from a spatiotemporal perspective,and the empirical insights can assist policymakers in creating intervention plans that take into account variations in OHDS spatiotemporal accessibility.

关键词： online home delivery services(OHDS) spatiotemporal accessibility neighborhoods accessibility differences Nanjing City china

Macro electrochemical milling and its hybrid variants

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Chinese Journal of Aeronautics 2024年第8期37卷 1-35页

作者： Ningsong QU Xiaolong FANG Junzhong ZHANG Huanghai kong Yang liu {2.lu WANG Xiaokang YUE Yuehong MA Zhihao {3. Jiajie CHEN College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China School of Mechanical Engineering Jiangsu UniversityZhenjiang 212003China School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Mechanical Engineering Hefei University of TechnologyHefei 230009China

Macro electromechanical milling has recently attracted increasing attention because numerous large thin-walled structures composed of difficult-to-cut materials are employed in the aerospace *** paper reviews recent developments in state-of-the-art macro electromechanical *** fundamental aspects of material removal mechanisms,such as the generation and breakdown behaviors of passive oxide films of typical difficult-to-cut materials,were *** methods for breaking down passive films are summarized,and simulation methods for the machining process coupling multiple physical fields are *** electrochemical milling methods,including fly mode electrochemical milling and sink electrochemical milling,are *** made to improve process performance,such as the material removal rate,surface quality,and machining accuracy,are *** addition,the main hybrid electrochemical milling methods,including electrochemical discharge milling,mechano-electrochemical milling,and electrochemical mill grinding,are also presented.

关键词： Electrochemical machining Electrochemical milling Material removal rate Surface quality Electrochemical discharge milling Electrochemical millgrinding

Effects of axylitol-casein complex on insulin resistance and gut microbiota composition in high-fat-diet+streptozotocin-induced type 2.diabetes mellitus mice

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Food Science and Human Wellness 2024年第5期13卷 2741-2753页

作者： Fanhua kong Juan Zhang Shimo Kang Xinyu shen Aicheng {2. Yan Zheng Junhua Shao Xiqing Yue College of Food Science Shenyang Agriculture UniversityShenyang 110866China

This study investigated the effects of a xylitol-casein non-covalent complex(XC)on parameters related to type 2.diabetes mellitus(T2.M),in addition to related changes in gut microbiome composition and ***-fat-diet(HFD)+streptozotocin(STZ)-induced T2.M mice were treated with xylitol(XY),casein(CN),and XC,after which fecal samples were collected for gut microbiota composition and diversity analyses based on 16S rRNA high-throughput sequencing and multivariate *** decreased body weight and improved glucose tolerance,insulin sensitivity,pancreas impairment,blood lipid levels,and liver function in T2.M mice compared to XY-and CN-treated ***,XC modulated theα-diversity,β-diversity and gut microbiota *** on Spearman’s correlation analysis,the relative abundances of Alistipes,Bacteroides,and Faecalibaculum were positively correlated and those of Akkermansia,Lactobacillus,Bifidobacterium,and Turicibacter were negatively correlated with the phenotypes related to the improvement of *** conclusion,we found that XC alleviated insulin resistance by restoring the gut microbiota of T2.M *** results provide strong evidence for the beneficial effects of XC on T2.M and motivation for further investigation in animal models and,eventually,human trials.

关键词： Xylitol-casein complex Type 2.diabetes mellitus Insulin resistance Gut microbiota

A Low Cost, Green Sustainable and Biodegradable Biomass-based Fluorine-free Water and Oil Repellent

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Chinese Journal of Polymer Science 2024年第4期42卷 480-491页

作者： Zhi-Wei shen Shu-Feng Hu Chen Zeng Wei-Qing kong Mei-Fang Zhu State Key Laboratory for Modification of Chemical Fibers&Polymer Materials College of Materials Science and EngineeringDonghua UniversityShanghai201620China State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510630China

With the global ban on plastics intensifying, the substitution of plastic with paper has garnered increasing attention. However, the inadequate water and oil repellency of pulp molding hinders its practical applications. Currently, the common method to enhance the oil and water repellency of pulp molding is by adding fluorinated water and oil repellents. Nevertheless, fluorinated compounds are environmentally and physiologically harmful. Therefore, the development of fluorine-free, water and oil repellent alternatives is crucial. In this study, chitosan and stearic acid were utilized as the first and second layers of the oil and water repellent coatings, respectively. The coated samples exhibited favorable water repellency, with a water contact angle of 116.4°, and excellent oil repellency, achieving a 12.12.rating on the kit scale. Importantly, the samples did not exhibit any leakage after being soaked in hot water and hot oil at 95±5℃ for 3. min, demonstrating remarkable performance as a barrier against hot water and oil. Moreover, the coated samples displayed outstanding mechanical properties, thermal stability, biodegradability, and recyclability. The approach presented in this study is simple, cost-effective, environmentally friendly, and represents a promising technique for producing fluoride-free, oil-and water-resistant pulp molding products.

关键词： Biomass Fluoride-free Oil-andwater-resistant Plasticfree