检索结果-南通市图书馆

亚洲精密工程、微纳技术国际会议

作者： Zhao Libo, Zhao Yulong, Jiang Zhuangde, Liu xiue state {2. Lab for Manufacturing Systems engineering Shaanxi Province MEMS center Institute of Precision engineering, school of mechanical engineering, xi'an jiaotong University xi'an jiaotong University Winner Instruments Co., LTD. Shaanxi, 710049,china

A high temperature lower range piezoresistive pressure microsensor based on the MEMS (Micro Electro-mechanical System) and SIMOX (Separation by Implantation of Oxygen) technology has been developed for the harsh environment application. This piezoresistive pressure microsensor's sensitive chip is constituted by silicon substrate, a thin silicon dioxide layer by SIMOX, four Wheatstone bridge p-type resistances in the measuring circuit layer by boron ion implantation and photolithography, stress matching layer with silicon nitride, and beam lead layer (Ti-Pt-Au) for connecting p-type resistance by sputtering, and a cavity like cup structure fabricated by the wet etching. A special silicon dioxide layer is fabricated by the SIMOX technology in the sensitive element, which solves the problem of the leak-current influence, so the pressure microsensor fabricated by high temperature packaging process can be used in the fields with high temperature up to 2.0℃. In contrast, the traditional solid-state piezoresistive pressure chip is not able to used in high temperature fields, because the leak-current through the p-n junction which is used to isolate the upper measuring circuit layer from the silicon substrate, will increases at the temperature above 12.℃, so the sensor's performance will be deteriorated under high temperature. Otherwise, some compensation methods have been studied, the thermal zero drift k0 and the thermal sensitivity ks of the pressure microsensor are easy to be less than 2.10-4FS/℃. In addition, this type pressure microsensor's range is up to 1MPa. The experimental results show that this pressure microsensor has good performances in the high temperature and is able to meet the requirements of the modern industry, such as aviation, wind tunnel, automobile industry, engine, etc.

关键词： High temperature, Piezoresistive pressure microsensor, MEMS, SIMOX

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Analysis of the effects of rising temperature for embankments under seismic loads in cold regions

引用

Research in Cold and Arid Regions 2009年第4期1卷 316-321页

作者： ZhiQiang Liu 1,2.Hao Lu 1 1.school of Civil engineering,Lanzhou {2. University,Lanzhou,Gansu 730070,china.2.state key laboratory of Frozen Soil engineering,Cold and Arid Regions Environmental and engineering Research Institute,Chinese Academy of sciences,Lanzhou,Gansu 730000,china. Lanzhou jiaotong Univ Sch Civil Engn Lanzhou 730070 Gansu Peoples R China Chinese Acad Sci Cold & Arid Reg Environm & Engn Res Inst State Key Lab Frozen Soil Engn Lanzhou 730000 Gansu Peoples R China

The effect of temperature rising for frozen soil because of dynamic load was investigated by indoor *** and railway embankments are always loaded by dynamic loads such as earthquakes and *** the Qinghai-Tibetan Plateau is a re-gion where earthquakes occur frequently,it is essential to consider the temperature-rising effect of earthquakes or vehicles on railway and road *** this paper and according to the theories of heat transfer and dynamic equilibrium equations,as-suming frozen soil as thermal elastic-viscoplastic material,taking the combination of thermal and mechanical stresses into account,we present the numerical formulae of this dynamic problem,and the computer program of the two-dimensional finite element is *** the program,the dynamic response analyses for embankments loaded by earthquake are worked *** in-dicated that the temperature-rising effect result from earthquakes for embankment in nonuniform distribution in some small areas,the ma{2.mum rising temperature is 0.16 ?C for consideration in this paper.

关键词： Qinghai-Tibetan railway temperature-rising effect frozen soil embankment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

硅/碳化硅材料显微特征与强度关系研究

引用

陶瓷学报 2004年第4期25卷 207-211页

作者：李世斌李养良金志浩九江学院材料工程系 332005 西安交通大学金属材料强度国家重点实验室 710049

通过改变坯体碳/碳化硅质量比,采用反应烧结方法制备了不同硅相含量和次生碳化硅分布形式的硅/碳化硅复合材料。探讨了该复合材料不同显微组织的形成机理。用三点弯曲法评价了材料强度与显微组织的关系,结合断口断裂模式,从热失配引起... 详细信息

通过改变坯体碳/碳化硅质量比,采用反应烧结方法制备了不同硅相含量和次生碳化硅分布形式的硅/碳化硅复合材料。探讨了该复合材料不同显微组织的形成机理。用三点弯曲法评价了材料强度与显微组织的关系,结合断口断裂模式,从热失配引起颗粒周围残余应力和界面能两个方面对强度-组织之间的关系进行了定性讨论。结果表明,硅/碳化硅相体积含量、碳化硅分布形态、热失配导致的残余应力是影响材料强度的主要因素,优化制备工艺参数是获得高性能材料的关键。

关键词：碳化硅材料反应烧结复合材料制备工艺坯体颗粒质量比体积含量三点弯曲失配

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

脉冲激光加热薄膜微尺度热传递研究进展

引用

物理学进展 2004年第2期24卷 152-162页

作者：徐红玉张元冲宋亚勤卢秉恒陈殿云西安交通大学机械结构强度与振动国家重点实验室西安710049 西安交通大学机械工程学院河南科技大学建筑工程学院

　短脉冲激光显微微加工因其具有制作高精度微结构的能力和其在现代微制作技术中的应用,微尺度薄膜热传递的研究受到极大关注,近年来对薄膜结构高频加热的研究迅猛发展。本文对十年来薄膜微尺度热传递的相关研究进展做了简要评述。

关键词：短脉冲激光薄膜热传递微尺度显微微加工薄膜结构

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characteristics of New-type Energy Absorber for Vehicle Collision

引用

Journal of Shanghai jiaotong university(science) 2008年第2期13卷 252-256页

作者：许庆新沈荣瀛周海亭 state key {2. of mechanical System and Vibration Shanghai Jiaotong University

A new type energy absorber was introduced,which is composed of thousands of thin ring plates with different *** it can switch the impact to thousands of shearing actions among thin ring plates inside the absorber,the impact energy is decentralized and dissipated gradually,the impact acting time is extended and the peak of acceleration is reduced *** simulations by finite element method (FEM) coupled with smoothed particle hydrodynamics (SPH) method were preformed to predict the energy absorption *** absorption ability with different impact velocities was studied and the effects of thickness and material of ring plates were *** sled crash test was carried out to validate the result of *** new type absorber is effective for collision that impact velocity is lower than 40 km/h.

关键词： energy absorber impact shear fracture numerical simulation smoothed particle hydrodynamics sled crash test

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

氯化锂/丙三醇改性玉米淀粉/聚对苯二甲酸-己二酸丁二醇酯复合材料的结构与性能

引用

高分子材料科学与工程 2024年第7期40卷 43-51页

作者：杜云婷王妤鑫邹金成杨贞旋张熙高分子材料工程国家重点实验室(四川大学)四川大学高分子研究所四川成都610065

为制备具有良好综合性能的淀粉(CS)/聚对苯二甲酸-己二酸丁二醇酯(PBAT)共混材料,以氯化锂(LiCl)和丙三醇(Gly)构建新型复合改性剂,提出了一步共混制备改性CS/PBAT共混材料的新方法。通过扫描电镜(SEM)、X射线衍射(XRD)、差示扫描量热分... 详细信息

为制备具有良好综合性能的淀粉(CS)/聚对苯二甲酸-己二酸丁二醇酯(PBAT)共混材料,以氯化锂(LiCl)和丙三醇(Gly)构建新型复合改性剂,提出了一步共混制备改性CS/PBAT共混材料的新方法。通过扫描电镜(SEM)、X射线衍射(XRD)、差示扫描量热分析(DSC)、力学性能测试等考察了复合改性剂中LiCl对淀粉的作用效果,探究了复合改性剂对CS/PBAT共混材料结构和性能的影响。结果表明,Gly/LiCl复合改性剂中LiCl的引入能够增强改性剂与淀粉羟基和PBAT酯基之间的电子相互作用,进一步破坏淀粉的氢键和颗粒结构,从而降低CS/PBAT的结晶度,改善淀粉与PBAT的相容性,提高共混材料的韧性、耐水性和降解性能,表现出比单纯丙三醇改性更好的作用效果。采用Gly和LiCl质量比10:1的复合改性剂,在CS和PBAT质量比为50:75时改性CS/PBAT共混材料具有优良的力学性能,其断裂伸长率从改性前的2..9%提高到了2.1.7%,拉伸强度从改性前的13.4 MPa变为10.8 MPa,下降不大,显示出良好的改性作用。

关键词：淀粉聚对苯二甲酸-己二酸丁二醇酯共混材料氯化锂丙三醇复合改性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Modeling and experimental investigation of useful flow-rate in flood delivery grinding

Modeling and experimental investigation of useful flow-rate ...

引用

2.09中国控制与决策会议

作者： C.H.Li~1,G.Y.Liu~2.Y.L.Hou~1,Y.C.Ding~1 and B.H.Lu~3 1.College of mechanical engineering,Qingdao Technological University,Qingdao,P.R.{2.,2.6033 2.Inner Mongolia University for Nationalities,Tongliao,P.R.{2.,02.042.3.state key laboratory for manufacturing systems engineering,xi’an jiaotong University,xi’an,P.R.{2.,{12.

In the grinding process,grinding fluid is delivered for the purposes of chip flushing,cooling,lubrication and chemical protection of work *** to high speed rotating grinding wheel,the boundary layer of air around the grinding wheel restricts most of the grinding fluid away from the grinding ***,conventional method of delivering grinding fluid that flood delivery is not believed to fully penetrate this boundary layer and,thus,the majority of the grinding fluid is deflected away from the grinding *** flood grinding typically delivers large volumes of grinding fluid was ineffective,especially under high speed grinding *** the paper,a theoretical model is presented for flow of grinding fluid through the grinding zone. The model shows that the flow rate through the contact zone between the wheel and the work surface depends on wheel porosity and wheel speed as well as depends on nozzle position,design,fluid jet ***,the model was tested by a surface grinding machine in order to correlate between experiment and ***,the useful flow-rate model was found to give a good description of the experimental results and the model can well forecast the useful flow-rate in flood delivery grinding.

关键词： Grinding Useful flow-rate Flood delivery Boundary layer

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Calculation of Transient Stress Field During Laser Transformation Hardening Process

引用

Journal of Shanghai jiaotong university(science) 2000年第1期5卷 82-85页

作者： Liwen Zhang, J. Th.M.De Hosson, Yuanliang xia, Fugang Wang 1.The state {2. laboratory for materials Modification by Laser, Ion and Electron Beams 2.material engineering Department of Dalian University of Technology, Dalian 11602.,china

A thermal elastic-plastic Two-D finite element model to calculate the transient stress field during laser transformation hardening process was developed in this paper. The mechanical properties of material, Young’s module E, Poisson’s ratio v, yield limit s2.and thermal expansion coefficient a are all considered to change with temperature. The equivalent expansion method was used to deal with the problem with phase transformation. A program to calculate the transient stress field was developed using FORTRAN language. The transient and residual stress fields during CO2.laser transformation hardening process of MoCu nodular iron were calculated. The residual stress fields were measured using X-ray diffraction method. The calculated residual stress field of laser transformation hardened MoCu nodular iron is in good agreement with the experimental result.

关键词： Laser Transformation Hardening Stress Field Finite Element

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

STUDY ON THE EFFECT OF FILLER ON THE ANTICORROSIVE PERFORMANCE OF FRP PRODUCTS

STUDY ON THE EFFECT OF FILLER ON THE ANTICORROSIVE PERFORMAN...

引用

Third East Asian Polymer Conference

作者： Cai Huiwu, Wang Guangheng Dept. of material engineering, {2.’an University of science & Technology, {2.’an 710054, china

The effect of adding inorganic mineral fillers with different types and particle size and proportions on the anticorrosive performance and mechanical properties of glass fiber reinforced plastic (FRP) products is studied by the static steep experiment, observing the exterior of samples and medium and the change of mechanical properties of samples.1 Experimental1.1 Sample structure designIn order to obtain good anticorrosive performance, the sample structure is designed as shown in Fig. 1.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Research on the Surface Micro-configuration in Vibration Cutting Particle Reinforced Metallic Matrix Composites SiCp /Al

Research on the Surface Micro-configuration in Vibration Cut...

引用

第十届国际制造工程与管理会议

作者： ZHAO Bo, LIU Chuan-shao, ZHU Xun-sheng, XU Ke-wei(1. Institute of mechanical engineering, Shanghai {2. University,Shanghai 2.0030, china 2. Department of mechanical engineering, Jiaozuo Institute of Technology,Henan 454000, china)

＜正＞ The cutting performance of particulate reinforced metallic matrix composites （PRM-MCs） SiCp/Al in ultrasonic vibration cutting and common cutting with carbide tools and PCD tools was researched in the paper. Microstructure of machined surface was described, the relation, between cutting parameters and surface roughness was presented, and characteristic of the surface remained stress was also presented. Furthermore, wear regularity and abrasion resistance ability of tools in ultrasonic vibration cutting and common cutting of PRMMCs were discussed in detail. The test results show- （1） The surface configurations are obviously different when using different tools to machine such PRMMCs. The surface machined with carbide tools looks luminous and orderly and there are seldom surface defects on it. The reason is that the soft basal body is apt to flow during cutting, therefore a layer of Al matrix film covers machined surface. On the contrary, the surface machined with PCD tools looks lackluster. But the profile of machined surface is very clear. Superfine grooves, pits and black reinforce particulates can be seen easily without obvious Al film. （2. Because of unstable cutting process in common cutting, the surface is easy to produce some defects such as burrs, built-up edges and so on so that the quality of surface becomes very poor. Vibration cutting can reduce the influence of tearing, plastic deformation and built-up edge in cutting and can restrain flutter so as to make cutting process more stable. Therefore, surface roughness of vibration cutting is better than that of common cutting. （3） There is an optimum value of feed rate in vibration cutting of PRMMCs due to the influence of material characteristics. Whether feed rate is more than or less than this optimum value, surface roughness will increase. （4） According to analyzing the wear rate of tools in vibration cutting PRMMCs, it can be concluded that abrasion resistance of tools will be improved remarkably whe

关键词： PCD tools composite SiCp/Al surface micro-configuration tool wear

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：