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Theoretical analysis and experiment of micromechanics and mechanics-optics coupling of distributed optic-fiber crack sensing

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中国科学：技术科学英文版 2011年第S1期54卷 185-191页

作者： LIU HaoWu 1,2,CHEN Jiang 2,SUN Man 3 & DING Rui 2 1 State Key Laboratory of Hydraulics and Mountain River engineering,Sichuan university,Chengdu 610065,china 2 School of Water Resource Hydropower,Sichuan university,Chengdu 610065,china 3 School electrical engineering and Information,Sichuan university,Chengdu 610065,china State Key Laboratory of Hydraulics and Mountain River engineering Sichuan University School of Water Resource Hydropower Sichuan University School electrical engineering and Information Sichuan University

The micromechanical behaviors and mechanics-optics coupling effects of optic-fiber-concrete complex in the distributed optic-fiber sensing concrete-crack technology,which was used in health monitoring of Wu Gorge Bridge on Yangtze River and a large dam successfully,have been investigated.A micromechanical theoretical analysis method and micromechanical frictional contact bi-interface model,as well as a modified optical theoretical analysis method of the mechanics-optics coupling effects are presented.A series of verification experiments,including mechanical experiments and mechanics-optics coupling experiments,have been *** results of micromechanical theoretical analysis and the analysis of the modified theory of mechanics-optics coupling along with mechanical and optical experimental data are shown to be in close *** the micromechanical theory and the modified theory of mechanics-optics coupling with their analysis methods can not only enhance credibility of this novel distributed sensing technology but also provide a way to understand its sensing mechanism and optimize its technical details and system.

关键词： optic-fiber sensing mechanics-optics coupling micromechanics health monitoring concrete structure crack detection

The Study on the Microstructure and mechanical Properties of 400MPa Grade Bar Prepared by Controlled Cooling After Finish Rolling

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Journal of Iron and Steel Research International 2011年第S1期18卷 610-614页

作者： ZHANG Jun-wei 1,DING Lei 1,XIAO Yi 2,3,HU Xiao-dong 1,HU Lin 1 (1.School of Materials and Metallurgy,university of science and technology Liaoning,Anshan 114051,Liaoning,china 2.Baosteel Nantong Co Ltd.,Nantong 226002,Jiangsu,china 3.School of electrical engineering,Anhui university of technology,Maanshan 243002,Anhui,china) Univ Sci & Technol Liaoning Sch Met & Mat Anshan 114051 Liaoning Peoples R China Baosteel Nantong Co Ltd Nantong 226002 Jiangsu Peoples R China Anhui Univ Technol Sch Elect Engn Maanshan 243002 Anhui Peoples R China

The production process of bars in Baosteel Nantong *** adjusted by both decreasing heating temperature and adding controlling cooling procedure after finish rolling for upgrade of bars.A set of water cooling system was also installed behind the finishing ***-line tests were conducted,and then the microstructure and mechanical properties of the bars with HRB335 composition and φ22mm diameter were *** results showed that the microstructures of the bar cooled by water were ferrite and pearlite with grain sizes of 8.5 to 12 grades,which were finer than that of the bar without water *** the thin outer layer microstructures of the bar cooled by water were mainly tempered sorbite with small amount of tempered *** average yield strength R eL and tensile strength R m of the bars with water cooling increased 105MPa and 73MPa respectively compared with those of the bars without water *** reason of this strengthening was attributed to the synthetic role of fine grains and phase transformation and precipitation *** addition,The ration of R m /R eL could be higher than 1.25,which is the request of earthquake-proof performance for HRB400E,only when the self-tempering temperatures of the bars were higher than 640℃.

关键词： controlled cooling hot rolling bar fine grain strengthening self-tempering

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太阳位置公式的改进及应用

水电能源科学 2011年第9期29卷 213-216页

作者：桂文胜李涛陆彦斌昆明理工大学机电工程学院云南昆明650093

针对现有太阳位置公式在实际应用中存在的不足,对公式中参数的意义及取值范围做了具体说明,采用公式计算取代用查表法确定参数,将现有太阳位置公式的三式改为两式,得出了计算日出日落的时刻和方位角的公式,验证了改进后公式的准确性,并... 详细信息

针对现有太阳位置公式在实际应用中存在的不足,对公式中参数的意义及取值范围做了具体说明,采用公式计算取代用查表法确定参数,将现有太阳位置公式的三式改为两式,得出了计算日出日落的时刻和方位角的公式,验证了改进后公式的准确性,并编制了Matlab程序,绘制了不同纬度、太阳位置、日出日落时刻和方位角随时间变化的曲线,可快速掌握太阳位置的变化规律。

关键词：太阳位置太阳高度太阳方位角日出日落时刻公式改进

DRAG REDUCTION EFFECT OF COUPLING FLEXIBLE TUBES WITH TURBULENT FLOW

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Journal of Hydrodynamics 2008年第1期20卷 96-100页

作者： CAI Shu-peng JIN Guo-yu LI Da-mei Yang Lin Institute of High Pressure Water Jet Hunan University of Technology Zhuzhou 421008 China State Key Laboratory of Water Resources and Hydropower engineering science Wuhan University Wuhan430072 China College of mechanical and electrical engineering Chongqing Jiaotong University Chongqing 400074 China

To analyze the mechanism of drag reducing effect by coupling flexible tubes with turbulent flow, based on experimental examination of more obvious turbulent drag reduction effect in flexible tubes than in rigid tubes, experimental investigation was performed on the effect of turbulent drag reduction, fluctuating vibration characteristics of flexible tube and the correlations by using a double-tube system and laser displacement sensor. The results are as follows： with the decrease of the thickness of the flexible tubes, the root mean square of fluctuating amplitude of the outer wall of the tubes increases, and the non-dimensional burst period increases, resulting in the increase of the reduction rate of drag coefficient by coupling flexible tubes with turbulent flow. At applied pressure-balanced air on the outer wall and the Reynolds number of about 1.75×10^4, the non-dimensional burst periods of the flexible tubes with the thickness of 2 mm, 3 mm, 4 mm are 141, 126, 105, respectively.

关键词： flexible tubes fluctuating displacement turbulent drag reduction burst period

Preparation and Property of Chromium Carbide Thermal Diffusion Coating on Cold Working Die Materials

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Journal of Wuhan university of technology(Materials science) 2010年第4期25卷 596-599页

作者：袁志华 School of electrical and mechanical engineering North University of China School of Equipment engineering Shenyang Ligong University

Thermal diffusion （TD） salt bath chromizing of cold working dies was studied. Firstly, it obtained an ideal salt bath formula by comparing with a variety of formulas, and then obtained the influence rule of coating thickness based on studying of some process parameters. The microstructure morphologies and phase structures of the TD chromizing coating were investigated by X-ray diffraction （XRD）, energy-dispersive spectrometry （EDS） and other modern analysis methods. Meanwhile, it carried out a system of testing and analysis of coating, such as hardness, wear resistance, etc.

关键词： chromium carbide coating thermal diffusion process cold working die preparation SEM EDS

Experimental measurement of growth patterns on fossil corals:Secular variation in ancient Earth-Sun distances

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Chinese science Bulletin 2010年第35期55卷 4010-4017页

作者： ZHANG WeiJia1,3,4,LI ZhengBin2,3 & LEI Yang1 1 Department of Physics,Peking university,Beijing 100871,china 2 Department of electrical engineering and Computer science,Peking university,Beijing 100871,china 3 State Key Laboratory of Advanced Optical Communication Systems & Networks,Peking university,Beijing 100871,china 4 Committee of Yuanpei Honors Program,Peking university,Beijing 100871,china Department of Physics Peking University Beijing China State Key Laboratory of Advanced Optical Communication Systems & Networks Peking University Beijing China Committee of Yuanpei Honors Program Peking University Beijing China Department of electrical engineering and Computer science Peking University Beijing China

In recent years,much attention has been given to the increase in the Earth-Sun distance,with the modern rate reported as 5-15 m/cy on the basis of astronomical ***,traditional methods cannot measure the ancient leaving rates,so a myriad of research attempting to provide explanations were met with unmatched *** this paper we consider that the growth patterns on fossils could reflect the ancient Earth-Sun *** mechanical analysis of both the Earth-Sun and Earth-Moon systems,these patterns confirmed an increase in the Earth-Sun *** a large number of well-preserved specimens and new technology available,both the modern and ancient leaving rates could be measured with high precision,and it was found that the Earth has been leaving the Sun over the past 0.53 billion *** Earth's semi-major axis was 146 million kilometers at the beginning of the Phanerozoic Eon,equating to 97.6% of its current *** modern leaving rates are 5-14 m/cy,whereas the ancient rates were much *** results indicate a special expansion with an average expansion coefficient of 0.57H0 and deceleration in the form of Hubble *** the basis of experimental results,the Earth's semi-major axis could be represented by a simple formula that matches fossil measurements.

关键词：地球太阳古代距离生长模式实验石珊瑚量化

Development of Flow Stress of AISI H13 Die Steel in Hard Machining

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Journal of Wuhan university of technology(Materials science) 2007年第2期22卷 187-190页

作者：闫洪 School of mechanical&electrical engineering Nanchang University

An approach was presented to characterize the stress response of workpiece in hard machining, accounting for the effect of the initial workpiece hardness in addition to temperature, strain and strain rate on flow stress in this paper. AISI H13 die steel was chosen to verify this methodology. The proposed flow stress model demonstrates a good agreement with experimental data. Therefore, the proposed model can be used to predict the corresponding flow stress-strain response ofAISl H13 die steel with variation of the initial workpiece hardness in hard machining.

关键词： flow stress hard machining finite element modeling AISI H13 die steel

HTS Transformer and Its Related Loss Measurement and Quench Protection Techniques

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HTS Transformer and Its Related Loss Measurement and Quench ...

Design and Analysis of Control System of a Proton Exchange Membrane Fuel Cell Directly Connected with a DC Motor

第二十七届中国控制会议

作者： Jin Jianxun 1,Chen Xiaoyuan 1,Guo Youguang 2,Zhan Yuedong 2,3,Zhu Jianguo 2 1.Center of Applied Superconductivity and electrical engineering,university of Electronic science and technology of china,Chengdu610054,P.R.china 2.faculty of engineering,university of technology,Sydney,NSW 2007,Australia 3.kunming university of science and technology,kunming,150001,P.R.china

Recently research and development concerning applications of high temperature superconducting（HTS） transformers have been progressed actively in the *** the HTS rated current capability,it is also essential to develop the relevant and precise performance test and protection systems for HTS *** paper mainly presents elementary test and protection methods of HTS transformers including AC loss measurement,and quench detection and protection.A new integrated measurement system for HTS transformers is also proposed by using the Labview virtual instrument software.

关键词： High Temperature Superconductor (HTS) HTS Transformer AC Loss Quench Protection Labview

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Design and Analysis of Control System of a Proton Exchange M...