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Research on Rare Earth Encapsulated Luminescent Material

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Journal of Rare Earths 2004年第Z1期22卷 153-156页

作者： yu zhiwei Liu Chengdong Qi Xiaopeng Material Science and Engineering Department East China Institute of Technology Fuzhou Jiangxi 344000China Material Science and Engineering Department East China Institute of Technology Fuzhou Jiangxi 344000China Material Science and Engineering Department East China Institute of Technology Fuzhou Jiangxi 344000China

A new method of preparation of irradiative material by using rare earth as luminophor and inorganic powder as base nucleus was *** earth was used to make colloid, which was mixed with base nucleus solution,where deposition/attachment reaction took place and rare earth was adhered onto the surface of base nucleus, hence yielding a new rare earth encapsulated irradiative *** spectrum analysis shows that this material possesses two emission peaks, one within 400 ～ 500 nm and the other within 580 ～ 700 nm, reflecting the luminous characteristics of original rare earth material.

关键词： irradiative material fluorescent analysis rare earths

Progress on Bionic Textured Cutting Tools:A Review and Prospects

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Journal of Bionic Engineering 2024年第1期21卷 19-55页

作者： Hong Wei Guangjun Chen Zhuang Chen zhiwei yu Jiashuai Huang Tianjin Key Laboratory of High Speed Cutting and Precision Processing Tianjin 300222China School of Mechanical Engineering Tianjin University of Technology and EducationTianjin 300222China

Cutting tools are known as the“productivity”of the manufacturing industry,which affects the production efficiency and quality of the workpiece,and has become the focus of research and attention in academia and ***,traditional cutting tools often suffer from adhesion or wear during the cutting process,which considerably reduces the cutting efficiency and service life of the tools,and makes it difficult to meet current production *** solve the above problems,scholars have introduced bionics into the tool’s design,applying the microscopic structure of the biological surface to the tool surface to alleviate the tool’s *** paper mainly summarizes the research progress of bionic textured cutting ***,categorize whether the bionic texture design is inspired by a single organism or multiple ***,it is discussed that the non-smooth surface of the biological surface has five characteristics:hydrophilic lubricity,wear resistance,drag reduction and hydrophobicity,anti-adhesion,and arrangement,and the non-smooth structure of these different characteristics are applied to the surface of the tool is designed with bionic ***,the cutting performance of bionic textured cutting tools is *** anti-friction and wear-resisting mechanism of bionic textured cutting tools is ***,some pending problems and perspectives have been proposed to provide new inspirations for the design of bionic textured cutting tools.

关键词： Bionic textured cutting tools Biological microstructure characteristics Cutting performance Anti-friction and wear-resisting mechanism

Status of research on non-conventional technology assisted single-point diamond turning

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Nanotechnology and Precision Engineering 2023年第3期6卷 79-92页

作者： Zhuang Chen Guangjun Chen zhiwei yu Jiashuai Huang Hong Wei Tianjin Key Laboratory of High Speed Cutting and Precision Processing Tianjin 300222China School of Mechanical Engineering Tianjin University of Technology and EducationTianjin 300222China

With the increasing use of difficult-to-machine materials in aerospace applications,machining requirements are becoming ever more ***,traditional single-point diamond turning(SPDT)can cause surface damage and tool ***,it is difficult for SPDT to meet the processing requirements,and it has significant *** indicates that supplementing SPDT with unconventional techniques can,importantly,solve problems due to the high cutting forces and poor surface quality for difficult-to-machine *** paper first introduces SPDT and reviews research into unconventional techniques for use with *** machining mechanism is discussed,and the main advantages and disadvantages of various methods are ***,hybrid SPDT is briefly described,which encompasses ultrasonic-vibration magnetic-field SPDT,ultrasonic-vibration laser SPDT,and ultrasonic-vibration cold-plasma *** with the traditional SPDT method,hybrid SPDT produces a better optical surface *** current status of research into unconventional techniques to supplement SPDT is then ***,future development trends and the application prospects of unconventional assisted SPDT are discussed.

关键词： Single-point diamond turning Machined surface quality Tool wear Unconventional auxiliary technique

Chronology of environmental events over East Asia during the past 130 ka

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Chinese Science Bulletin 1998年第21期43卷 1761-1769页

作者： Zhongli Ding Jimin Sun zhiwei yu Dongsheng Liu Chinese Acad Sci Inst Geol Beijing 100029 Peoples R China China Univ Min Dept Geol Xuzhou 221008 Peoples R China

In the transitional region between the Loess Plateau and deserts, 4 sections located respectively at yuling, Hengshan, Dingbian and Huining of China are studied. The high-resolution paleoclimatic records obtained show that environmental events on varying time scales have happened over East Asia. These events are dated with the time scales established using the recently-developed approach of Automatic Orbital Tuning. This leads to the establishment of the chronology of the environmental events.

关键词： environmental events time scale Chinese loess.

Nonlinear least-square iteration for calibrating gyroscopic drift error coefficients based on vibration table 36

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Nonlinear least-square iteration for calibrating gyroscopic ...

Intermittent failure mechanism and stabilization of microscale electrical contact

第36届中国控制会议

作者： Zhongxian Zou Ming Zeng zhiwei yu yu Liu Xin Zhang Space Control and Inertial Technology Research Center Harbin Institute of Technology Department of Control Science and Engineering Harbin Institute of Technology

ISBN: (纸本)9781538629185

This work presents a nonlinear least-square iterative algorithm for calibrating gyroscopic drift error based on vibration *** to the practical data analysis of the output acceleration of vibration table,the output acceleration errors are verified to be periodic harmonic errors with certain harmonic amplitudes in repetitively tests when the running frequency of vibration table is ***,the present researches pay little attention on gyroscope calibration that is affected by the periodic *** this paper,the periodic harmonic acceleration errors are considered,and the nonlinear least-square iteration algorithm is applied to deal with the periodic harmonic *** shows that the solution obtained by nonlinear least-square iterative algorithm is much better than that solved by linear least-square method.

关键词： Gyroscopic drift error calibration vibration table nonlinear least-square iteration

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Friction 2023年第4期11卷 538-545页

作者： Tianbao MA zhiwei yu Aisheng SONG Jiahao ZHAO Haibo ZHANG Hongliang LU Dandan HAN Xueyan WANG Wenzhong WANG State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Inspur Beijing Electronic Information Industry Co. Ltd.Beijing 100085China Department of Precision Instrument Tsinghua UniversityBeijing 100084China Innovation Center for Future Chips Beijing 100084China State Key Laboratory of Precision Measurement Technology and Instruments Beijing 100084China School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China Institute of Physics Chinese Academy of SciencesBeijing 100190China

The stability and lifetime of electrical contact pose a major challenge to the performance of microelectro-mechanical systems(MEMS),such as MEMS *** microscopic failure mechanism of electrical contact still remains largely *** conductive atomic force microscopy with hot switching mode was adopted to simulate the asperity-level contact condition in a MEMS *** variation and fluctuation of current and adhesion force were observed during 10,000 repetitive cycles,exhibiting an“intermittent failure”*** fluctuation of electrical contact properties was attributed to insulative carbonaceous contaminants repetitively formed and removed at the contact spot,corresponding to degradation and reestablishment of electrical *** contaminant film was formed,the contact interface became“metal/carbonaceous adsorbates/metal”instead of direct metal/metal contact,leading to degradation of the electrical contact ***,a system of iridium/graphene on ruthenium(Ir/GrRu)was proposed to avoid direct metal/metal contact,which stabilized the current fluctuation and decreased interfacial adhesion *** existence of graphene enabled less adsorption of carbonaceous contaminants in ambient air and enhanced mechanical protection against the repetitive hot switching *** work opens an avenue for design and fabrication of microscale electrical contact system,especially by utilizing two-dimensional materials.

关键词： atomic force microscopy microscale electrical contact graphene

Optimized Bio-inspired Micro-pillar Dry Adhesive and Its Application for an Unmanned Aerial Vehicle Adhering on and Detaching from a Ceiling

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Journal of Bionic Engineering 2020年第1期17卷 45-54页

作者： Qingsong He Xianrui Xu zhiwei yu Kai Huo Zhaoyang Wang Nuo Chen Xuean Sun Gui Yin Peile Du Yang Li Zhendong Dai Institute of Bio-inspired Structure and Surface Engineering Jiangsu Provincial Key Laboratory of Bionic Functional MaterialsCollege of Mechanical and Electrical EngineeringNanjing University of Aeronautics&AstronauticsNanjing 210016China College of Astronautics Nanjing University of Aeronautics&AstronauticsNanjing 210016China China Ship Development and Design Center Shanghai Branch Shanghai 201108China

Various bio-inspired dry adhesive materials have been *** this work,lithography and silicon deep etching method were used to fabricate bio-inspired micro-pillar dry adhesive materials of which the parameters,such as side length,Height to Side length Aspect Ratio(HSAR),and inter-pillar Distance to Side length Aspect Ratio(DSAR)were comprehensively studied to obtain a dry adhesive with high *** orthogonal array method was designed and a series of fabrication experiments were conducted to identify optimum parameters,which resulted in a high normal adhesion of 2.98 N·cm^-2 and a shear adhesion of 9.59 N·cm^-*** adhesion and desorption device was further designed on basis of the optimum dry adhesive,which enables an Unmanned Aerial Vehicle(UAV)to successfully adhere on and detach from a *** would allow an UAV to stay aloft for prolonged time,which could be invaluable to many applications,such as energy conservation and aerial detection.

关键词： bio-inspired dry adhesive orthogonal array method UAV adhere ceiling

Wheel-legged In-pipe Robot with a Bioinspired Hook and Dry Adhesive Attachment Device

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Journal of Bionic Engineering 2024年第3期21卷 1208-1222页

作者： Yahong Liu Yi Sun Kai Cao Shutao Wu Xiaofeng Xu Qingfei Han Shikun Wen Huan Shen Guangming Chen Jiajun Xu zhiwei yu Aihong Ji Lab of Locomotion Bioinspiration and Intelligent Robots College of Mechanical and Electrical EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In-pipe robots have been widely used in pipes-with smooth inner ***,current in-pipe robots face challenges in terms of moving past obstacles and climbing in marine-vessel pipeline systems,which are affected by marine biofouling and electrochemical *** paper takes inspiration from the dual-hook structure of Trypoxylus dichotomus’s feet and gecko‑like dry adhesives,proposing an in-pipe robot that is capable of climbing on rough and smooth pipe *** combination of the bioinspired hook and dry adhesives allows the robot to stably attach to rough or smooth pipe inwalls,while the wheel-leg hybrid mechanism provides better conditions for obstacle *** paper explores the attachment and obstacle-surmounting mechanisms of the ***,motion strategies for the robot are devised based on different pipe structural *** experiments showed that this robot can adapt to both smooth and rough pipe environments simultaneously,and its motion performance is superior to conventional driving *** robot’s active turning actuators also enable it to navigate through horizontally or vertically oriented 90°bends.

关键词： In-pipe robot Bioinspired attachment device Wheel-legged robot Mechanical design

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世博文化中心主体结构设计与分析

建筑结构学报 2010年第5期31卷 95-102页

作者：余志伟华东建筑设计研究院有限公司上海200002

上海世博文化中心碟形主体结构由36榀悬臂长度不等的桁架和内框架结构组成。结构受力以静荷载为主。有效控制桁架端部的变形及减小桁架和内框架的受力是该结构设计的重点。设计时分析了结构的受力特点并针对关键构件进行了加强,首先在... 详细信息

上海世博文化中心碟形主体结构由36榀悬臂长度不等的桁架和内框架结构组成。结构受力以静荷载为主。有效控制桁架端部的变形及减小桁架和内框架的受力是该结构设计的重点。设计时分析了结构的受力特点并针对关键构件进行了加强,首先在内框架顶部设置两道矩形钢管主环梁;其次将六层楼板加厚为200mm,并在楼板应力大的桁架第一节间位置铺设钢板。上述措施如同在36榀内框架顶部加了一道"紧箍",显著减小了桁架端部变形及主要构件的受力。动力分析表明:该结构的振动特性不同于普通的高层建筑,扭转成为第1振型,但结构具有相当大的侧向刚度,且抗侧力构件分布均匀,并采用钢框架结构,在水平地震作用下不致出现脆性破坏。为研究楼板刚度对结构的影响,建立了考虑楼板刚度、不考虑楼板刚度及单榀框架等3个计算模型,分析了主要杆件在这3个计算模型下受力的差异,结果表明,楼板刚度对主要杆件的受力有显著影响,但对不同的杆件受力影响有所不同,设计时须取3个计算模型下的包络结果进行设计。

关键词：长悬臂桁架扭转楼板刚度环向拉力