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Some studies on mechanics of continuous mediums viewed as differential manifolds

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Science China(Physics,Mechanics & Astronomy) 2013年第2期56卷 432-456页

作者： XIE xilin CHEN Yu SHI Qian Department of Mechanics & Engineering Science Fudan University

The continuous mediums are divided into two kinds according to their geometrical configurations,the first one is related to Euclidian manifolds and the other one to Riemannian manifolds/surfaces in the point of view of the modern *** kinds of finite deformation theories with respect to Euclidian and Riemannian manifolds have been developed in the present *** kinds of theories include the definitions of initial and current physical and parametric configurations,deformation gradient tensors with properties,deformation descriptions,transport theories and governing equations of nature conservation *** essential property of the theory with respect to Euclidian manifolds is that the curvilinear coordinates corresponding to the current physical configurations include time explicitly through which the geometrically irregular and time varying physical configurations can be mapped in the diffeomorphism manner to the regular and fixed domains in the parametric *** is quite essential to the study of the relationships between geometries and *** theory with respect to Riemannian manifolds provides the systemic ideas and methods to study the deformations of continuous mediums whose geometrical configurations can be considered as general *** essential property of the theory with respect to Riemannian manifolds is that the thickness variation of a patch of continuous medium is represented by the surface density and its governing equation is rigorously *** some applications,wakes of cylinders with deformable boundaries on the plane,incompressible wakes of a circular cylinder on fixed surfaces and axisymmetric finite deformations of an elastic membrane are numerically studied.

关键词： continuous mediums finite deformation theories Euclidian and Riemannian manifolds intrinsic generalized Stokes for-mulas wakes of cylinders with deformable boundaries flows on surfaces finite amplitude vibrations of membranes fluiddynamics on deformable boundaries

1.56 kV/30 A vertical β-Ga2O3 Schottky barrier diodes with composite edge terminations

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Science China(Information Sciences) 2025年

作者： Yitao FENG Hong ZHOU Sami ALGHAMDI Hao fang Xiaorong ZHANG Yanbo CHEN Guotao TIAN Saud WASLY Yue HAO Jincheng ZHANG Key Lab of Wide Band Gap Semiconductor Materials and Devices School of MicroelectronicsXidian University Center of Excellence in Intelligent Engineering Systems (CEIES) King Abdulaziz University China Resources Microelectronics Limited(Wuxi)

In recent years, large-area wide-bandgap (WBG) semiconductor materials have achieved numerous notable breakthroughs [1, 2]. The ultra-WBG semiconductor β-Ga2O3,with its excellent material properties, is ideally suited for the fabrication of power devices. Moreover, it offers easily obtainable large-area substrates, with reported sizes up to 6 inches, produced through melt-grown crystal growth methods. These characteristics make β-Ga2O3 highly attractive for future low-cost commercialization. Despite these advances, most research has focused on low-current and small-size diodes, with few studies addressing high-current and large-size diodes.

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动态序列情境对面部表情知觉的影响和作用机制

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心理科学进展 2025年第1期33卷 1-10页

作者：方霞潘之禾浙江大学心理与行为科学系杭州310058

现实生活中,面部表情通常随时间推移呈动态变化,个体对任一表情的解读都可能受其所处的动态序列情境的影响。尽管近年来有研究表明同时呈现的情境信息会对目标表情的知觉产生影响,但对于序列变化的表情信息如何影响目标表情知觉却知之... 详细信息

现实生活中,面部表情通常随时间推移呈动态变化,个体对任一表情的解读都可能受其所处的动态序列情境的影响。尽管近年来有研究表明同时呈现的情境信息会对目标表情的知觉产生影响,但对于序列变化的表情信息如何影响目标表情知觉却知之甚少。本研究拟通过行为实验和眼动技术,借助人工合成和真人表演的动态表情,考察序列变化的表情信息(即动态序列情境)对初始表情和最终表情的知觉的影响及其作用机制。研究成果有助于揭示生态化情境下的面部表情加工机制,为基于人工智能的动态表情识别提供参考。

关键词：面部表情情绪知觉动态序列情境

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Study on the effect of the infill walls on the seismic performance of a reinforced concrete frame

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Earthquake Engineering and Engineering Vibration 2011年第4期10卷 507-517页

作者： Zhang Cuiqiang Zhou Ying Zhou Deyuan Lu xilin Research Institute of Structural Engineering and Disaster Reduction Tongji University Shanghai 200092 China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji University Shanghai 200092 China

Motivated by the seismic damage observed to reinforced concrete （RC） frame structures during the Wenchuan earthquake, the effect of infill walls on the seismic performance of a RC frame is studied in this paper. Infill walls, especially those made of masonry, offer some amount of stiffness and strength. Therefore, the effect of infill walls should be considered during the design of RC frames. In this study, an analysis of the recorded ground motion in the Wenehuan earthquake is performed. Then, a numerical model is developed to simulate the infill walls. Finally, nonlinear dynamic analysis is carried out on a RC frame with and without infill walls, respectively, by using CANNY software. Through a comparative analysis, the following conclusions can be drawn. The failure mode of the frame with infill walls is in accordance with the seismic damage failure pattern, which is strong beam and weak column mode. This indicates that the infill walls change the failure pattern of the frame, and it is necessary to consider them in the seismic design of the RC frame. The numerical model presented in this paper can effectively simulate the effect of infill walls on the RC frame.

关键词： infill walls RC frame structure strong column and weak beam strong beam and weak column nonlinear time history analysis

Positive effect of Mo on mechanical properties of a Ni-42W-10Co-x Mo medium heavy alloy

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China Foundry 2025年

作者： Guo-xin Cao Jian-xin Dong Yong-sheng He He Jiang fang Hao Zhi-hua Nie Teng-fei Ma Bao-quan Fu School of Materials Science and Engineering University of Science and Technology Beijing Xi'an Superalloy Technology Co. Ltd. School of Materials Science and Engineering Beijing Institute of Technology Key Laboratory of Air-driven Equipment Technology of Zhejiang Province Quzhou University

In this study,a novel Ni-W-Co-Mo medium heavy alloy (MHA) was designed to improve its mechanical strength via Mo *** the Ni-42W-10Co-xM o alloy series,where x represents the weight percent of Mo and varies between 0,1,2,5,and 10,the microstructure transitions from a dendritic structure to a hypoeutectic structure as the Mo content increases from 0 to 5wt.%.Moreover,as the Mo content increases from 0to 10wt.%,the distribution of theμ-phase shifts from being individually dispersed to forming aggregates,and its volume fraction rises from 0.5%to 7.9%.Notably,theμ-phase evolves into an eutectic microstructure,which helps in minimizing the segregation of *** change is accompanied by a substantial enhancement in mechanical properties;specifically,the compressive yield strength at room temperature increases from 350 MPa to 646 MPa,indicating a significant 85%***,the microhardness increases from 230 HV to 304 *** dynamics simulations further reveal that the strengthening mechanism of Ni-42W-10Co-xM o alloys is Mo-induced solid solution strengthening and precipitation strengthening.

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Shake table testing of a multi-tower connected hybrid structure

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Earthquake Engineering and Engineering Vibration 2009年第1期8卷 47-59页

作者： Zhou Ying Lu xilin Lu Wensheng He Zhijun State Key Laboratory for Disaster Reduction in Civil Engineering Tongji University Shanghai 200092 China Architectural Design and Research Institute Tongii University Shanghai 200092 China

Many single-tower reinforced concrete core wall-steel frame （RCC-SF） buildings have been built in China, but there are no buildings of different-height multi-tower hybrid system. A multi-tower RCC-SF tall building was thus studied because of its structural complexity and irregularity. First, a 1/15 scaled model structure was designed and tested on the shake table under minor, moderate, and major earthquake levels. Then, the dynamic responses of the model structure were interpreted to those of the prototype structure according to the similitude theory. Experimental results demonstrate that, despite the complexity of the structure, the lateral deformation bends as the ＂bending type＂ and the RC core walls contribute more than the steel frames to resist seismic loads. The maximum inter-story drift of the complex building under minor earthquakes is slightly beyond the elastic limitation specified in the Chinese code, and meets code requirements under major earthquakes. From the test results some suggestions are provided that could contribute favorable effect on the seismic behavior and the displacement of the building.

关键词： complex building hybrid structure scaled model shake table testing seismic performance

Nitrous oxide emissions from black soils with different pH

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Journal of Environmental Sciences 2013年第6期25卷 1071-1076页

作者： Lianfeng Wang Huachao Du Zuoqiang Han xilin Zhang College of Environmental and Chemical Engineering Dalian Jiaotong University State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of Sciences Institute of Soil and Fertilizers Heilongjiang Academy of Agricultural Sciences

N2O fluxes as a function of incubation time from soil with different available N contents and pH were determined. Cumulative carbon dioxide （CO2） emissions were measured to indicate soil respiration. A 144-hr incubation experiment was conducted in a slightly acidic agricultural soil （PHH2o 5.33） after the pH was adjusted to four different values （3.65, 5.00, 6.90 and 8.55）. The experiments consisted of a control without added N, and with NH^-N and NO^-N fertilization. The results showed that soil pH contributed significantly to N20 flux from the soils. There were higher N20 emissions in the period 0-12 hr in the four pH treatments, especially those enhanced with N- fertilization. The cumulative NEO-N emission reached a maximum at pH 8.55 and was stimulated by NO3-N fertilization （70.4 μg/kg）. The minimum emissions appeared at pH 3.65 and were not stimulated by NO3^--N or NH4^＋-N fertilization. Soil respiration increased significantly due to N-fertilization. Soil respiration increased positively with soil pH （R2 = 0.98, P 〈 0.01）. The lowest CO2-C emission （30.2 mg/kg） was presented in pH 3.65 soils without N-fertilization. The highest CO2-C emissions appeared in the pH 8.55 soils for NH4^＋-N fertilization （199 mg/kg）. These findings suggested that N20 emissions and soil respiration were significantly influenced by low pH, which strongly inhibits soil microbial nitrification and denitrification activities. The content of NO3^--N in soil significantly and positively affected the N2O emissions through denitrification.

关键词： N2O emission nitrification denitrification pH soil respiration

Recent progress of MXenes as the support of catalysts for the CO oxidation and oxygen reduction reaction

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Chinese Chemical Letters 2020年第4期31卷 931-936页

作者： Yiying Zhang xilin Zhang Cheng Cheng Zongxian Yang School of Physics Henan Normal UniversityXinxiang 453007China College of Chemistry Key Laboratory of Theoretical&Computational Photochemistry of Ministry of EducationBeijing Normal UniversityBeijing 100875China National Demonstration Center for Experimental Physics Education(Henan Normal University) Xinxiang 453007China

MXenes,the new family of two-dimensional(2D)transition metal carbides/nitrides,can serve as the substrate materials for the catalysts due to the large specific surface area,tunable electronic structures and thermal *** first 2D layered MXene,Ti3C2,was successfully obtained by selective etching of the A element from the MAX phases using hydrofluoric acid(HF)at room temperature in *** this review,we summarize the preparation,structure of MXenes and discuss the recent progress in potential application of MXenes in catalysis,mainly in CO oxidation and oxygen reduction reaction(ORR),from the views of both experimental and theoretical inve *** outlook of the major challenges and future directions on research of MXenes is also included.

关键词： MXenes Catalysis Substrate material CO oxidation ORR

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基于粒子群算法的纯电动商用车转矩分配策略

江苏大学学报（自然科学版） 2025年第1期46卷 1-8,27页

作者：田韶鹏方正武汉理工大学汽车工程学院湖北武汉430070

针对纯电动商用车采用双电动机驱动时存在的转矩分配问题,提出基于粒子群算法的模糊控制策略.首先在Simulink/Stateflow软件中搭建整车动力系统物理模型,以粒子群算法为基础,进行整车转矩分配.由于计算量大,无法运用于实车,故根据粒子... 详细信息

针对纯电动商用车采用双电动机驱动时存在的转矩分配问题,提出基于粒子群算法的模糊控制策略.首先在Simulink/Stateflow软件中搭建整车动力系统物理模型,以粒子群算法为基础,进行整车转矩分配.由于计算量大,无法运用于实车,故根据粒子群算法的结果,结合传统项目经验,设计一个参数实时调节模糊控制器来进行转矩分配.该方法运行速度快,且基本达到粒子群全局优化的效果.验证与分析结果表明:与原车单电动机动力系统相比,采用该方法的双电动机动力系统能量消耗减少了12.08%;在双电动机动力系统下,该方法与平均分配控制策略相比,电动机总能量损失降低了13.09%.

关键词：纯电动商用车双电动机驱动转矩分配粒子群算法模糊控制策略