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Hydrogen Sensing Characteristics of ZnSnO3 Micro-Particles Doped with Noble Metal Pd

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稀有金属材料与工程 2006年第S3期 167-169页

作者： Jiaqiang Xu~1 Xiaohua Jia~2.Xiangdong Lou~2.(1.college of Material and Chemical engineering,{2. university of Light Industry,{2. 450002.china) (2.college of Chemistry and Environmental Science,Henan Normal university,Xinxiang 453007,china)

Perovskite-type oxide ZnSnO3doped with 0.5 wt% Pd was prepared directly by a hydrothermal process,its crystal structure and ceramic microstructure were characterized by XRD and TEM,and the gas sensing properties were tested in static *** is found that the sensors based on ZnSnO3micro-particles have good sensitivity and selectivity to *** sensitivity can be changed with working temperature;the sensitivity of the sensors to H2.ould arrive 2. times when the working temperature is 332..

关键词： hydrothermal method perovskite-type oxide gas sensor ZnSnO3

A geometrical and physical nonlinear finite element model for spatial thin-walled beams with arbitrary section

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Science china(Technological Sciences) 2010年第3期53卷 829-838页

作者： YANG QingShan 1 &WANG XiaoFeng 2.1 School of civil engineering,Beijing Jiaotong {2.,Beijing 100044,china 2.college of civil engineering,Tongji {2.,Shanghai 2.0092.china 1. School of civil engineering Beijing Jiaotong University Beijing 100044 China2. College of Civil Engineering Tongji University Shanghai 200092 China

Based on the theories of Bernoulli-Euler beams and Vlasov's thin-walled members,a new geometrical and physical nonlinear beam element model is developed by applying an interior node in the element and independent interpolations on bending angles and warp,in which factors such as traverse shear deformation,torsional shear deformation and their coupling,coupling of flexure and torsion,and second shear stress are all ***,geometrical nonlinear strain in total Lagarange(TL) and the corresponding stiffness matrix are *** plastic model is applied to physical nonlinearity to comply with the yield rule of Von Mises and incremental relationship of *** stiffness matrix is derived by numerical integration on the basis of the finite segment *** show that the developed model is feasible in analysis of thin-walled structures with high accuracy.

关键词： Spatial beams thin-walled structures geometrical and physical nonlinearity finite element arbitrary section

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Noble Metal-Doped In2.3 for Enhancing Response to H2

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稀有金属材料与工程 2006年第S3期 136-139页

作者： Jiaqiang Xu~(1,2. Xiaohua Wang~1 Jianian Shen~2.(1.college of Materials and Chemical engineering,{2. university of Light Industry,{2. 450002.china) (2.Institute of Materials,Shanghai university,Shanghai 2.0072.china)

Nanocrystalline In2.3was synthesized through a controllable solvothermal process in one-step at 2.0℃for 2. h. Gas sensing properties were tested by mixing gas in air in static *** 2.8.5℃,the nanocrystal showed high sensitivity to LPG but lower sensitivity to H2.nd *** order to enhance the sensitivities to H2.nd CO,0.5 mass % Au and Pd were doped by an impregnation *** sensitivities to H2.nd CO were increased under different working ***-doped In2.3was superior to Pd-doped In2.3whatever to H2.r CO;the sensitivity was increased with the increase of working temperature;gas sensing properties to H2.vermatched to CO.

关键词： solvothermal process indium oxide noble metal H2.sensor

Preparation and NO2.Sensing Characteristics of LaFeO3 Nanoparticles

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稀有金属材料与工程 2006年第S3期 165-166页

作者： Xiangdong Lou~1 Xiaohua Jia~1 Jiaqiang Xu~2.(1.college of Chemistry and Environmental Science,Henan Normal university,Xinxiang 453007,{2.) (2.college of Materials and Chemical engineering,zhengzhou university of Light Industry,zhengzhou 450002.{2.)

LaFeO3nanoparticles were prepared by decomposing a precursor La[Fe（CN）6]·4H2. at 800℃,the precursor was synthesized by a coordination precipitation process at room *** decomposing mechanism of the precursor was investigated by analyzing TG-DSC *** crystal structure,particle size and ceramic microstructure were characterized by X-ray diffraction （XRD） and transmission electron microscopy （TEM）.Furthermore,the gas sensing properties were tested at static *** can be shown that LaFeO3nanoparticles are highly crystallized after sintering at 800℃,the particle size is about 50 *** sensor based on LaFeO3nanoparticles shows remarkable sensitivity to NO2.

关键词： thermal decomposition gas sensor LaFeO3

Gas Sensing Properties of ZnO Tetrapod-Like Whiskers Prepared by Hydrothermal Process

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稀有金属材料与工程 2006年第S3期 185-187页

作者： Jiaqiang Xu~(1,2. Yuping Chen~1 Huanxin Wang~1 Jianian Shen~2.(1.college of Materials and Chemical engineering,{2. university of Light Industry,{2. 450002.china) (2.Institute of Materials,Shanghai university,Shanghai 2.0072.china)

ZnO tetrapod-like whiskers were prepared through a hydrothermal process using zinc powder as raw *** microstructure and morphology were characterized by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. The XRD results showed that the crystal structure of as-obtained sample can be indexed to hexagonal wurtzite *** results revealed that the ZnO sample took on tetrapod-like whisker *** gas sensors were prepared with the traditional sintering process and their gas sensitivities were *** test results of gas sensitivity showed that the sensors based on ZnO tetrapod-like whiskers are very sensitive to dilute ethanol vapor and *** relatively high sensitivity and selectivity of these sensors made from ZnO tetrapod-like whiskers demonstrated the potential for developing a new class of selective ethanol sensors.

关键词： hydrothermal process gas sensor zinc oxide whisker

Research and progress of Beidou satellite navigation system

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Science china(Information Sciences) 2012年第12期55卷 2899-2907页

作者： SUN FuPing ,LIU Shuai,ZHU XinHui & MEN BaoHong college of Navigation and Aerospace engineering,Information engineering university,zhengzhou 450052.china 1. college of Navigation and Aerospace engineering Information Engineering University Zhengzhou 450052 China

The paper gives a brief review of the development course and strategic planning of Beidou satellite navigation system,and introduces its construction progress,with emphasis on the research progress of some key technologies of Beidou,including navigation constellation design,navigation signal structure and performance,compatibility and interoperability,precise orbit determination,navigation and precise *** main problems and challenges of Beidou are described.

关键词： Beidou satellite navigation system navigation constellation design navigation signal structure and performance compatibility and interoperability precise orbit determination navigation and precise positioning

Gasoline Sensor Based on Flower-Like ZnO

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稀有金属材料与工程 2006年第S3期 106-109页

作者： Xu Jiaqiang~(1,2. Chen Yuping~1 Li Chao~1 Shen Jianian~2.(1.college of Materials and Chemical engineering,{2. university of Light Industry,{2. 450002.china) (2.Institute of Materials,Shanghai university,Shanghai 2.0072.china)

Flower-like ZnO was prepared through a hydrothermal process using zinc sulfate as raw *** microstructure and morphology of the samples were characterized by X-ray diffraction （XRD） and transmission electron microscopy （TEM）.XRD results showed that the as-obtained sample could be indexed to hexagonal wurtzite *** results revealed that the ZnO sample presented flower-like *** gas sensors were prepared with the traditional sintering process and their gas sensitivities were *** gas sensitivity results showed that the sensors based on flower-like ZnO were very sensitive to dilute 90#*** relatively high sensitivity and selectivity of these sensors made from flower-like ZnO demonstrated the potential for developing a new class of selective gasoline sensors.

关键词： hydrothermal process gas sensor zinc oxide gasoline

Unified solutions for stresses and displacements around circular tunnels using the Unified Strength Theory

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Science china(Technological Sciences) 2010年第6期53卷 1694-1699页

作者： ZHANG ChangGuang1,WANG JiangFeng2.& ZHAO JunHai3 1 Department of Geotechnical engineering,Tongji university,Shanghai 2.0092.{2. 2.North {2. Institute of Water Conservancy and Hydroelectric Power,zhengzhou 450011,{2. 3 School of civil engineering,Chang’an university,Xi’an 710061,{2. 1. Department of Geotechnical engineering Tongji University Shanghai 200092 China2. North China Institute of Water Conservancy and Hydroelectric Power Zhengzhou 450011 China3. School of Civil Engineering Chang’an University Xi’an 710061 China

The unified solutions are presented for stresses and displacements around a circular tunnel subjected to a hydrostatic stress *** rock mass is assumed to be elastic-brittle-plastic and governed by the Unified Strength *** displacements are obtained accounting for three different definitions for elastic strains and different Young's modulus in the plastic *** unified solutions obtained in this paper are especially versatile in reflecting the intermediate principal stress effect to different extents for different *** conventional solutions,based on the Mohr-Coulomb failure criterion and the Generalized Twin Shear Stress yield criterion,are special cases of the present unified *** new unified solutions can compare with those computed by the latest generalized Hoek-Brown failure *** results obtained demonstrate the importance of the intermediate principal stress influence for the stresses and displacements *** effects of different definitions for elastic strains and different Young's modulus in the plastic zone on the displacements are significant.

关键词： Unified Strength Theory intermediate principal stress different definitions for elastic strains different Young’s modulus

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Integrated intelligent control analysis on semi-active structures by using magnetorheological dampers

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Science china(Technological Sciences) 2008年第12期51卷 2270-2284页

作者： XU ZhaoDong1 & GUO YingQing2.1civil engineering {2., Southeast university, Nanjing 2.0096, china 2.Automation {2., Southeast university, Nanjing 2.0096, china civil engineering {2. Southeast University Nanjing 210096 China Automation college Southeast University Nanjing 210096 China

The control strategy is very important for semiactive control or active control systems. An integrated intelligent control strategy for building structures incorpo rated with magnetorheological (MR) dampers subjected to earthquake excitation is proposed. In this strategy, the time-delay problem is solved by a neural network and the control currents of the MR dampers are determined quickly by a fuzzy controller. Through a numerical example of a three-storey structure with one MR damper installed in the first floor, the seismic responses of the uncontrolled, the intelligently controlled, the passiveon controlled, and the passive-off controlled structures under different earthquake excitations are analyzed. Based on the numerical results, it can be found that the time domain and the frequency domain responses are reduced effectively when the MR damper is added in the structure, and the integrated intelligent control strategy has a better earthquake mitigation effect.

关键词： magnetorheological damper semi-active control intelligent

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