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TRANSMISSION MOMENTARY EFFICIENCY BASED ON THE D'ALEMBERT-LAGRANGE EQUATION FOR INVOLUTES GEARS

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Chinese Journal of Mechanical Engineering 2004年第2期17卷 272-275页

作者： Liang Yi Lai Changying School of Mechanical Engineering,nanjing university of science and Technology,{2.094, China School of Mechanical Engineering Nanjing University of Science and Technology Nanjing 210094 China Department of science and Technology Studies University College London WC1E 6BT UK

The D'Alembert-Lagrange equation is introduced and used to derive theformulas of momentary efficiency for external gearing of standard involutes spur gears. The gearingswith correct and increased center distance are discussed. The momentary efficiency formula iscalculated and analyzed using software Matlab. The derived formula of momentary efficiency is alsocompared with the traditional formula.

关键词： D'Alembert-Lagrange equation Involutes gear Momentary efficiency

Landscape structure and land uese on county level in northeastern Yunnan Province of China——a case study of Huize County

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Journal of Environmental sciences 2000年第3期12卷 355-360页

作者： WANG Jin\|liang, NI Shao\|xiang (College of Geographical science, nanjing Normal university, nanjing 2.0097, China) 南京师范大学江苏南京 2 1 0 0 97

Taking Huize County as an example, the paper analyzed the landscape structure(landscape element structure, landscape type structure, landscape spatial structure, landscape succession structure) and the relations between landscape structure and land use. It was pointed out that the agriculture should be developed in harmony with the landscape structure in the study area.

关键词： landscape structure land use agriculture Yunnan Province China

L-R smash products for bimodule algebras

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Progress in Natural science:Materials International 2006年第6期16卷 580-587页

作者： ZHANG Liangyun (Department of Mathematics, nanjing Agricultural university, {2.095, China Department of Mathematics, nanjing university, {2.008, China) [a] Department of Mathematics Nanjing Agricultural University Nanjing China [b] Department of Mathematics Nanjing University Nanjing China

In this paper, we prove that the L-R smash product A(?)H is exactly the twisted smash product A * H if H is a finite dimensional cocommutative Hopf algebra, and give a sufficient and necessary condition for L-R smash products to be bialgebras (Hopf algebras) . For any finite dimensional coquasitriangular Hopf algebra (H,σ), we prove that the L-R smash product H(?)H is semisimple Artinian if H is semisimple and H * is unimodular. In particular, the L-R smash product D(H)* (?)D(H)* semisimple Artinian if the Drin-fel'd double D(H) is semisimple.

关键词： bimodule algebras L-R smash products coquasitriangular Hopf algebras Long bialgebras.

Wavelet estimation of the diffusion coefficient in time dependent diffusion models

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science China Mathematics 2007年第11期50卷 1597-1610页

作者： Ping CHEN~(1,2+) Jin-de WANG~1 1 Department of Mathematics,nanjing university,nanjing 2.0093,China 2 School of science,nanjing university of science and Technology,nanjing 2.0094,China Department of Mathematics Nanjing University Nanjing 210093 China School of science Nanjing University of Science Technology Nanjing 210094 China

The estimation problem for diffusion coefficients in diffusion processes has been studied in many papers,where the diffusion coefficient function is assumed to be a 1-dimensional bounded Lipschitzian function of the state or the time *** is no previous work for the nonparametric estimation of time-dependent diffusion models where the diffusion coefficient depends on both the state and the *** paper introduces and studies a wavelet estimation of the time-dependent diffusion coefficient under a more general assumption that the diffusion coefficient is a linear growth Lipschitz *** the properties of martingale,we translate the problems in diffusion into the nonparametric regression setting and give the Lr convergence rate.A strong consistency of the estimate is *** this result one can estimate the time-dependent diffusion coefficient using the same structure of the wavelet estimators under any equivalent probability *** example,in finance,the wavelet estimator is strongly consistent under the market probability measure as well as the risk neutral probability measure.

关键词： wavelet estimation time-dependent diffusion coefficient linear growth condition strong consistency

Quantitative structure－activity study on the reductive dehalogenation potency of the halogenated aromatics

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Journal of Environmental sciences 1995年第2期7卷 183-189页

作者： Huang Qingguo Wang Liansheng Han Shuokui(Department of Environmental science and Technology, nanjing university , {2.008 , China) Dept of Envmlt Sci & Tech Nanjing Univ Nanjing China

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关键词： quantitative structure - activity relationship(QSAR) halogenated arornatics dehalogenation poten-cy discriminant function.

Dynamic damage and stress-strain relations of ultra-high performance cementitious composites subjected to repeated impact

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science China(Technological sciences) 2010年第6期53卷 1520-1525页

作者： LAI JianZhong1 & SUN Wei2 1 Department of Materials science and Engineering,nanjing university of science and Technology,nanjing 2.0094,China 2 College of Materials science and Engineering,Southeast university,nanjing 211189,China 1. Department of Materials science and Engineering Nanjing University of Science and Technology Nanjing 210094 China2. College of Materials Science and Engineering Southeast University Nanjing 211189 China

Ultra-high performance cementitious composites (UHPCC) were prepared by replacing 60% of cement with ultra-fine industrial waste *** dynamic damage and compressive stress-strain relations of UHPCC were studied using split Hopkinson pressure bar (SHPB).The damage of UHPCC subjected to repeated impact was measured by the ultrasonic pulse velocity *** show that the dynamic damage of UHPCC increases linearly with impact times and the abilities of repeated impact resistance of UHPCC are improved with increasing fiber volume *** stress waves on impact were recorded and the average stress,strain and strain rate of UHPCC were calculated based on the wave propagation *** effects of strain rate,fibers volume fraction and impact times on the stress-strain relations of UHPCC were *** show that the peak stress and elastic modulus decrease while the strain rate and peak strain increase gradually with increasing impact times.

关键词： ultra-high performance cementitious composites (UHPCC) split Hopkinson pressure bar (SHPB) repeated impact damage stress-strain

On power allocation for a cognitive radio network with hybrid spectrum sharing

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science China(Information sciences) 2011年第11期54卷 2425-2434页

作者： ZHANG Jing 1,2,3 & ZHU HongBo 1 1 Key Laboratory of Wireless Communications of Jiangsu Province,nanjing university of Posts & Telecommunications,nanjing 2.0003,China 2 College of Electronic science & Engineering,nanjing university of Posts & Telecommunications,nanjing 2.0003,China 3 State Key Laboratory of Millimeter Waves,nanjing 2.0096,China 1. Key Laboratory of Wireless Communications of Jiangsu Province Nanjing University of Posts & Telecommunications Nanjing 210003 China2. College of Electronic Science & Engineering Nanjing University of Posts & Telecommunications Nanjing 210003 China3. State Key Laboratory of Millimeter Waves Nanjing 210096 China

In this study we propose a hybrid spectrum sharing scheme based on power control by combining Overlay with Underlay schemes,to improve radio spectrum *** the scheme,the secondary users dynamically switch their operational states between Overlay and Underlay according to the spectrum *** the dynamics of the primary network is first modeled with a discrete-state Markov process to find the time fraction of secondary users in the Overlay state and that in the Underlay state,which leads to the capacity model of the hybrid spectrum sharing *** the criterion of maximizing capacity,the power allocation of the cognitive network is researched and the optimum power allocation for secondary users is *** a result,the maximum achievable capacity of the cognitive network is *** are given to prove the analysis *** and simulated results indicate that hybrid spectrum sharing based on power control provides a higher capacity than single Overlay and Underlay systems for the cognitive network,i.e.,hybrid spectrum sharing can further improve radio spectrum efficiency.

关键词： cognitive radio network hybrid spectrum sharing primary network dynamics power allocation achievable capacity

Three-dimensional investigation of velocity skin effect in U-shaped solid armature

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Progress in Natural science:Materials International 2008年第12期18卷 1565-1569页

作者： Xin Li~a Chunsheng Weng~b a School of Power Engineering,nanjing university of science and Technology,{2.094,China b National Key Laboratory of Transient Physics,nanjing university of science and Technology,{2.094,China [a]School of Power Engineering Nanjing University of Science and Technology Nanjing 210094 China [b]National Key Laboratory of Transient Physics Nanjing University of Science and Technology Nanjing 210094 China

A three-dimensional transient computational model is applied to investigate the velocity skin effect (VSE) in a U-shaped solid arma- *** this model,current and heat transport in the armature can be evaluated *** results show a local concentration of current and joule heating at the interface,and significant damage occurs at the edges of the *** is also observed that there is significant enhanced heating at sharp comers because of the armature *** three-dimensional model can efficiently capture the salient features of the physical phenomena at the rail-armature interface,and contribute to the development of the armature design.

关键词： Electromagnetic launch Railgun U-shaped armature Velocity skin effect Erosion

Inner Attitude Integration Algorithm Based on Fault Detection for Strapdown Inertial Attitude and Heading Reference System

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Chinese Journal of Aeronautics 2010年第1期23卷 68-74页

作者： Liu Jianye,Zhu Yanhua,Lai Jizhou,Yu Yongjun Navigation Research center,nanjing university of Aeronautics and Astronautics,{2.016,China [a] Navigation Research center Nanjing University of Aeronautics Astronautics Nanjing 210016 China

This article proposes a new inner attitude integration algorithm to improve attitude accuracy of the strapdown inertial attitude and heading reference system （SIAHRS） , which, by means of a Kalman filter, integrates the calculated attitude from the accelerometers in inertial measuring unit （IMU） , called damping attitudes, with those from the conventional IMU. As vehicle＇ s acceleration could produce damping attitude errors, the horizontal outputs from accelerometers are firstly used to judge the vehicle＇ s motion so as to determine whether the damping attitudes could be reasonably applied. This article also analyzes the limitation of this approach. Furthermore, it suggests a residual chi-square test to judge the validity of damping attitude measurement in real time, and accordingly puts forward proper information fusion strategy. Finally,the effectiveness of the proposed algorithm is proved through the experiments on a real system in dynamic and static states.

关键词： navigation strapdown inertial attitude and heading reference system inner attitude integration algorithm internal damping Kalman filter residual chi-square test