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Journal of Materials Science & Technology 2001年第2期17卷 197-202页

作者： Xiufeng HAN State key laboratory of Magnetism, institute of physics, chinese academy of sciences, beijing 100080, China Terunobu Miyazaki Department of Applied physics, Graduate School of engineering, Tohoku University, Aoba-yama 08, Sendai 980-8579, Japa State key lab. of Magnetism Inst. of Phys. Chinese Acad. of Sci. Beijing 100080 China

Temperature dependence of tunnel magnetoresistance (TMR) ratio, resistance, and coercivity from 4.2 K to room temperature (RT), applied de bias voltage dependence of the TMR ratio and resistances at 4.2 K and RT, tunnel current I and dynamic conductance dI/dV as functions of the de bias voltage at 4.2 K, and inelastic electron tunneling (IET) spectroscopy, d(2)I/dV(2) versus V, at 4.2 K for a tunnel junction of Ta(5 nm)/Ni79Fe21(25 nm)/Ir22Mn78(12 nm)/Co75Fe25(4 nm)/Al(0.8 nm)-oxide/Co75Fe25(4 nm)/Ni79Fe21(25 nm)/Ta(5 nm) were systematically investigated. High TMR ratio of 59.2% at 4.2 K and 41.3% at RT were observed for this junction after annealing at 275 degreesC for an hour. The temperature dependence of TMR ratio and resistances from 4.2 to 300 K at 1.0 mV bias and the de bias voltage dependence of TMR ratio at 4.2 K from 0 to 80 mV can be evaluated by a comparison of self-consistent calculations with the experimental data based on the magnon-assisted inelastic excitation model and theory. An anisotropic wavelength cutoff energy of spin-wave spectrum in magnetic tunnel junctions (MTJs) was suggested, which is necessary for self-consistent calculations, based on a series of IET spectra observed in the MTJs.

关键词： off TMR A Self-consistent Calculation and an Anisotropic Wavelength Cut Energy of Spin-wave Spectrumin Magnetic Tunnel Junctions wave Figure than

Microstructure and Wear Resistance Evolution of HVOFSprayed WC-(W,Cr)_2C-Ni Coating with Post Heat Treatment In Air Atmosphere

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稀有金属材料与工程 2012年第S1期41卷 388-393页

作者： Hou Guoliang1,2,Zhou Huidi1,An Yulong1,2,Liu Guang1,2,Chen Jianmin1,Chen Jie1,2 1 State key laboratory of Solid Lubrication,Lanzhou institute of Chemical physics,chinese academy of sciences,Lanzhou 730000,China 2 Graduate University,chinese academy of sciences,beijing 100049,China chinese Acad Sci Lanzhou Inst Chem Phys State Key Lab Solid Lubricat Lanzhou 730000 Peoples R China chinese Acad Sci Grad Univ Beijing 100049 Peoples R China

WC-(W,Cr)2C-Ni coating was prepared on 1Cr18Ni9Ti stainless steel and C-276 Ni-base Hastelloy by high velocity oxy-fuel(HVOF)*** effect of post heat treatment in air atmosphere on the microstructure,phase composition,microhardness,fracture toughness,and wear resistance of HVOF-sprayed WC-(W,Cr)2C-Ni coating was *** microstructure and phase composition of the coatings were analyzed by means of field emission scanning electron microscopy(FESEM)and X-ray diffraction(XRD).The microhardness and fracture toughness of the coatings were measured using a microhardness tester and a Vickers hardness ***,dry friction and wear behavior of the coatings sliding against Si3N4 ball was investigated using an oscillating friction and wear tester;and the worn surfaces of the coatings were analyzed by means of scanning electron microscopy(SEM).It was found that heat treatment within 500-800°C resulted in crystallization of amorphous phase in as-sprayed coating,generating nanoscale new phases such as NiWO4,CrWO4 and ***,heat treatment led to increase of the microhardness of as-sprayed coating,and the highest microhardness was obtained after heat treatment at 800°*** fracture toughness and wear resistance of the as-sprayed coating increased with increasing heat treatment temperature up to 700°C but tended to decrease with further elevating *** other words,the mechanical properties and wear resistance of the as-sprayed coatings were worsened owing to excessive growth of oxidation grains and depletion of ductile Ni binder after heat treatment above 700°*** it was suggested that as-sprayed ceramic composite coating should be post heat treated in air at a moderate temperature of 700°C so as to achieve the optimized mechanical properties and wear resistance.

关键词： HVOF WC-(W,Cr)2C-Ni coating post heat treatment microstructure wear resistance

Fabrication of Transparent Superhydrophilic TiO_2 Nanofilm without UV-irradiation

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稀有金属材料与工程 2012年第S1期41卷 263-267页

作者： Du Wen1,2,Ye Yinping1,Li Hongxuan1,Zhao Fei1,2,Ji Li1,Quan Weilong1,2,Chen Jianmin1,Zhou Huidi1 1 State key laboratory of Solid Lubrication,Lanzhou institute of Chemical physics,chinese academy of sciences,Lanzhou 730000,China 2 Graduate University of chinese academy of Science,beijing 100049,China chinese Acad Sci Lanzhou Inst Chem Phys State Key Lab Solid Lubricat Lanzhou 730000 Peoples R China chinese Acad Sci Grad Univ Beijing 100049 Peoples R China

A transparent phase-pure anatase TiO2 nanofilm was prepared through magnetron sputtering method,and a subsequent annealing treatment awarded it the superhydrophilic *** make clear the mechanism of the heat-induced superhydrophilicity,the chemical composition and surface morphology of the film were investigated in detail and compared before and after the annealing treatment mainly by field emission scanning electron microscopy(FESEM),X-ray diffraction method(XRD),Raman spectroscopy,and X-ray photoelectron spectroscope(XPS).The results suggest that the probable mechanism is in accordance with the UV-induced mechanism,where the heat-induced surface oxygen vacancies and hydroxyl radicals play important roles for achieving the superhydrophilicity.

关键词： superhydrophilicity transparent TiO2 nanofilms magnetron sputtering annealing treatment

Research on the LN2 Auto-filling System for Dewar Vessel based on Bang-Bang + PID Control

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Research on the LN2 Auto-filling System for Dewar Vessel bas...

On Suppression Technologies of Switching Harmonics Based on VVVF

2010 chinese Control and Decision Conference

作者： Shuhua Ma~(1,2),Junjie Wang~2,Jinkuan Wang~1,Cheng Cui~2,Yiding Zhao~1 1.School of Information Science and engineering,Northeastern University,Shenyang,110004,China 2.The key laboratory of cryogenics,technical institute of physics and chemistry,chinese academy of sciences,beijing,100190, China

＜正＞An automatic liquid nitrogen（LN2） filling system is *** the process of LN2 automatic filling applied in the cooling of the CCD camera applied in the Large Sky Area Multi Object Fiber Spectroscopic Telescope（LAMOST） there exist problems such as imprecise system model,time varying parameter and stronger interference from the load,which result in the overflow of LN2 or insufficient amount of LN2 in the automatic filling of the Dewar *** solve the above problems,a new method of low power heating of the sensors is *** control electromagnetic valve through Bang-Bang control,and PID algorithm for heating are *** on the spot indicate the above combined control has solved the described problems to make sure the LN2 through automatic filling meets the requirements for astronomical observation and that the LAMOST operates in a stable and reliable way.

关键词： Auto-filling Dewar vessel LN2 Bang-bang heating

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On Suppression Technologies of Switching Harmonics Based on ...

Ageing behaviour of Pd40Cu30Ni10P20 bulk metallic glass during long-time isothermal annealing

第三十届中国控制会议

作者： MA Shuhua~(1,2),LIN Han~1,WANG Junjie~2 1.College of Information Science and engineering,Northeastern University,Shenyang 110819,P.R.China 2.The key laboratory of cryogenics,technical institute of physics and chemistry,chinese academy of sciences, beijing 100190,P.R.China

＜正＞In order to suppress the switching harmonics in subsection synchronous modulation algorithm,two proposals,zero voltage switching half cycle and voltage phase compensation,are *** verify the performance of the above two solutions,simulation circuit is built by PSIM software and then experiments are carried out on VWF prototype based on *** and experimental results both confirm the effectiveness and practicality of the two solutions.

关键词： Subsection Synchronous Modulation Zero Voltage Switching Half Cycle Phase Compensation PSIM

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Ageing behaviour of Pd40Cu30Ni10P20 bulk metallic glass duri...

航空遥感平台通用物理模型及可变基高比系统精度评价

第九届全国正电子谱学会议

作者： J F Wang, L Liu, B Y Wang, C L Zhou, W Long Department of Materials Science and engineering, Chongqing University, 400044 Chongqing, People’s Republic of China The State key lab of Plastic Forming Stimulation and Die & Mould Technology, Huazhong University of Science & Technology, 430074 Wuhan, People’s Republic of China lab of Nuclear Analysis and Technology, institute of High Energy physics, chinese academy of sciences, 100039 beijing, People’s Republic of China

In this paper, positron annihilation spectroscopy and differential scanning calorimetry wereapplied to study the structural relaxation of Pd40Cu30Ni10P20 bulk metallic glass during long-timeannealing at 523 K. It was found that the relaxation of the alloy follows a two-stage process (it isseen in Fig.l, Fig.2 and Fig.3). In the initial stage, with increasing annealing time, the height ofthe glass transition peak (namely △cp) increased, while the average positron lifetime *** isothermal relaxation kinetics obeys a Kohlrausch law with exponent of β= 0.5 ±0.03 (it is

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测绘学报 2018年第6期47卷 748-759页

作者：晏磊李英成赵世湖袁修孝宋妍钟裕标薛庆生北京大学遥感与地理信息系统研究所北京市空间信息集成与3S应用北京市重点实验室北京100871 中国测绘科学研究院北京100039 中测新图(北京)遥感技术有限责任公司北京100039 国家测绘地理信息局卫星测绘应用中心北京101300 武汉大学遥感信息工程学院湖北武汉430079 中国地质大学(武汉)信息工程学院湖北武汉430074 中国科学院长春光学精密机械与物理研究所吉林长春130033

精度是高分辨率遥感和摄影测量的关键。影响精度的因素分为:成像系统误差和数据处理误差。航空平台系统误差较为复杂,因此本文聚焦航空成像系统设计方法,以降低航空成像系统误差为目标,从源头上为数据处理精度提供保障。目前航空数字成... 详细信息

精度是高分辨率遥感和摄影测量的关键。影响精度的因素分为:成像系统误差和数据处理误差。航空平台系统误差较为复杂,因此本文聚焦航空成像系统设计方法,以降低航空成像系统误差为目标,从源头上为数据处理精度提供保障。目前航空数字成像系统种类繁多,但缺乏统一物理模型,使得航空相机系统采用人工拼接为多刚体(多相机),结构复杂、体积大、成本高、精度难以刻画,容易受到震动和温度等因素影响,成像系统装机实用精度只能达到毫米量级。为此,本文构建航空遥感平台通用物理模型,由此归纳出现有航摄相机的四类对偶技术特征:一次-二次成像、外拼接-内拼接、单基线-多基线、非严格-严格中心投影;以此建立可变基高比时空模型,从而实现数字航摄相机内部光学机械参数与地表高程精度的表达,实现地表高程精度-光机参数贯通;进一步设计二次成像数字航摄相机原型系统及宽波段临边成像光谱仪,为目前多刚体拼接的一次成像航摄相机构建向精密光机单刚体、折反式同光路构建提供原型依据,为数字航摄系统构建和工业化奠定理论基础和原型实例参考。

关键词：系统精度数字航摄相机通用物理模型可变基高比时空模型单刚体 n次折反式同光路系统