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Mechanism of liquid zinc corrosion on metals

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International Journal of Minerals,Metallurgy and Materials 1997年第3期11卷 22-26页

作者： CAO Xiaoming , LONG Yi WANG Run2 (Department of Materials and Science, Hebei university of Technology, Tianin 300130, china) (Materials Science and Engineering School, university of Science and Technology Beijing, Beijing 100083, china)

Two kinds of materials, soluble and insoluble in liquid zinc, such as Fe and FeB, are separately dealt with.A new theory is presented for insoluble materials. Based on the theory, the surface defects of insoluble mate... 详细信息

关键词： liquid zinc corrosion mechanism boronize

Autonomous Navigation for Unmanned Aerial Vehicles Based on Chaotic Bionics Theory

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Journal of Bionic Engineering 2009年第3期6卷 270-279页

作者： Xiao-lei Yu~(1,2) Yong-rong Sun~1 Jian-ye Liu~1 Bing-wen Chen~31.Navigation Research Centre,Nanjing Universi~ of Aeronautics and Astronautics,Nanjing 210016,P.R.china2.Institute for Technology Research & Innovation,Deakin university,Vic 3217,Australia3.Institute.for Unmanned Aerial Vehicle Research,Beihang university,Beijing 100083,P.R.china [a]Navigation Research Centre Nanjing University of Aeronautics and Astronautics Nanjing 210016 P. R. China [b]Institute for Technology Research & Innovation Deakin University Vic 3217 Australia [c]Institute for Unmanned Aerial Vehicle Research Beihang University Beijing 100083 P. R. China

In this paper a new reactive mechanism based on perception-action bionics for multi-sensory integration applied to Un- manned Aerial Vehicles (UAVs) navigation is *** strategy is inspired by the olfactory bulb neural activity observed in rabbits subject to external *** new UAV navigation technique exploits the use of a multiscroll chaotic system which is able to be controlled in real-time towards less complex orbits,like periodic orbits or equilibrium points,considered as perceptive *** are subject to real-time modifications on the basis of environment changes acquired through a Synthetic Aperture Radar (SAR) sensory *** mathematical details of the approach are given including simulation results in a virtual en- *** results demonstrate the capability of autonomous navigation for UAV based on chaotic bionics theory in com- plex spatial environments.

关键词： chaotlc system perception-action bionlcs UAV,multi-sensoty integration autonomous navigation

Predicting the Maintainability of Open Source Software Using Design Metrics

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Wuhan university Journal of Natural Sciences 2008年第1期13卷 14-20页

作者： ZHOU Yuming1,2, XU Baowen1,3 1. School of Computer Science and Engineering, Southeast university, Nanjing 210096, Jiangsu,china 2. Department of Computing, Hong Kong Polytechnic university, Hong Kong, china 3. Jiangsu Institute of Software Quality, Nanjing 210096, Jiangsu,china School of Computer Science and Engineering Southeast University Nanjing China Department of Computing Hong Kong Polytechnic University Hong Kong China Jiangsu Institute of Software Quality Nanjing China

This paper empirically investigates the relationships between 15 design metrics and maintainability of 148 Java open source software. The results show that size and complexity metrics are strongly related to the maintainability of open source software. However, cohesion and coupling, as currently captured by existing metrics, do not seem to have a significant impact on maintainability. When used together, these metrics can predict system maintainability fairly accurately （mean MREs below 30%）.

关键词： open source: object-oriented maintainability metric prediction regression

Physical simulation of fluid flow and production performance in extra-low permeability porous media

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Petroleum Science 2009年第4期6卷 415-420页

作者： You Yuan Yue Xiang’an Li Mingyi Zhao Chunpeng Zhang Tao Key Laboratory of Petroleum Engineering Ministry of EducationChina University of PetroleumBeijing 102249China Enhanced Oil Recovery Research Center China University of PetroleumBeijing 102249China Jilin Oil Field PetroChinaSongyuanJilin 138000China Exploration&Production Research Institute SinopecBeijing 100083China Exploration Department Changqing Oil FieldPetroChinaXi’anShaanxi 710018China

For extra-low permeability reservoirs, with a permeability of about 0.3×10?3 μm2, fluid flow and production performance in cores were studied. A long core holder with a multi-location piezometric measurement was specially designed. An artificial long core, about 700 mm long and with a cross section of 45mm×45mm, was used. In the experiment, pressure distribution along the core can be measured in real time. Single phase flow in the core was investigated. Different modes of production in long cores were also simulated including natural depletion, water flooding, and advanced water flooding. Through physical simulation, flow parameters were collected and production characteristics in extra-low permeability cores were studied. From experimental results, it can be seen that fluid flow in extra-low permeability cores is different from that in high permeability cores. Transmission of pressure in extra-low permeability cores is very slow, and it needs a long time for the pressure to become stable. The distribution curve of pressure along the core is nonlinear and the production rate in extra-low permeability reservoirs decreases sharply. The development effects of different production modes in extra-low permeability cores were compared with one another. Among the production modes, advanced water flooding has much potential for effective development of extra-low permeability reservoirs. Natural depletion and conventional water flooding can also be used in early production periods. In addition, the countermeasures and some ideas especially for the potential development of extra-low permeability reservoirs are suggested.

关键词： Extra-low permeability reservoirs physical simulation fluid flow production performance

DYNAMIC CHARACTERISTICS OF LIQUID FORCED SLOSHING IN A TURNING SPHERICAL TANK WITH A SPACER UNDER LOW GRAVITY

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Journal of Hydrodynamics 2008年第2期20卷 202-209页

作者： CHENG Xu-duo HU Mei-zhu WEN Ji-hua School of Food Science and Engineering Nanjing University of Finance and Economics Nanjing 210003China Department of physics Anqing Teachers College Anging 246011 China

Under the condition of low gravity the characteristics of liquid forced sloshing in a turning spherical tank with a spacer were investigated. The static shape of the liquid surface was analyzed. By expanding the characteristic functions, the frequencies and velocity potential of liquid free-sloshing were derived. The governing equations and boundary conditions for the forced sloshing of liquid under the tank turning were established. The transverse force of liquid acting on the tank and the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer were given. Numerical results were compared with the ones of the spherical tank without a spacer. The results show that when a spacer is inserted in the tank, the sloshing frequency of liquid and the transverse force of liquid acting on the tank will decrease, but the moment of force to the centre of the tank which is caused by the force of liquid acting on the spacer will occur.

关键词： low gravity forced sloshing of liquid sloshing suppression

INDUCTION PLASMA REACTIVE DEPOSITION OF TUNGSTEN CARBIDE FROM TUNGSTEN METAL POWDER

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Acta Metallurgica Sinica(English Letters) 2001年第5期14卷 352-358页

作者： X.L. Jiang Institute of Surface and Coatings Technology, Central South university, Changsha 410083, china M.I. Boulos Department of Chemical Engineering, university of Sherbrooke, Sherbrooke, J1K 2R1, Canada Central South Univ. Changsha 410083 China

Experimental results on the primary carburization reaction between the tungsten powder and methane in the induction plasma, and the secondary carburization of the deposit on substrate at high temperature are reported. Optical microscopy and scanning electron microscopy were used to examine the microstructures of starting tungsten powder, carburized powder, and deposit. X-ray diffraction analysis, thermal gravimetric analysis and microhardness measurement were used to characterize the structures and properties of the powder and the deposit. It is found that the primary carburization reaction in the induction plasma starts from the surface of tungsten particles when the particles are melted. Tungsten particles are partially carburized inside the reactive plasma. Complete carburization is achieved through the secondary carburization reaction of the deposit on substrate at high temperature.

关键词： Carburizing Deposition Methane Powder metals Tungsten Tungsten carbide

晶体的X射线衍射理论——劳厄与埃瓦尔德的遗产

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物理 2003年第7期32卷 434-440页

作者：冯端冯少彤南京大学物理系南京210093 南京师范大学物理系南京210024

文章概述了晶体X射线衍射理论的发展过程 ,介绍了不同形式的衍射几何理论、劳厄方程、布拉格方程与埃瓦尔德作图法 ,讨论了它们之间的异同之处 .文章还介绍了运动学衍射理论和不同形式的动力学衍射理论 ,后者包括达尔文的简化处理、埃... 详细信息

文章概述了晶体X射线衍射理论的发展过程 ,介绍了不同形式的衍射几何理论、劳厄方程、布拉格方程与埃瓦尔德作图法 ,讨论了它们之间的异同之处 .文章还介绍了运动学衍射理论和不同形式的动力学衍射理论 ,后者包括达尔文的简化处理、埃瓦尔德的表述和劳厄的表述 ,并对其物理后果进行了讨论 ,强调了动力学理论所预言的电磁波在周期结构中传播所引起的能隙 .

关键词：晶体 X射线衍射理论衍射几何理论劳厄方程布拉格方程埃瓦尔德作图法运动学衍射理论动力学衍射理论

A fusion algorithm for remote sensing images based on nonsubsampled pyramids and bidimensional empirical decomposition

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Science china(Technological Sciences) 2010年第S1期53卷 196-204页

作者： ZHANG XiaoDong 1,WANG WenBo 2,WANG DiFeng 3 & ZHANG Yu 4 1 State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan university,Wuhan 430079,china 2 College of Sciences,Wuhan university of Science and Technology,Wuhan 430065,china 3State Key Laboratory of Satellite Ocean Environment Dynamics,Second Institute of Oceanography,State Oceanic Administration,Hangzhou 310012,china 4 Spatial Information Technology Application Research Institute,Changjiang River Scientific Research Institute,Wuhan 430010,china Wuhan Univ State Key Lab Informat Engn Surveying Mapping & R Wuhan 430079 Peoples R China Wuhan Univ Sci & Technol Coll Sci Wuhan 430065 Peoples R China State Ocean Adm Inst Oceanog 2 State Key Lab Satellite Ocean Environm Dynam Hangzhou 310012 Zhejiang Peoples R China Changjiang River Sci Res Inst Spatial Informat Technol Applicat Res Inst Wuhan 430010 Peoples R China

In order to improve the quality of remote sensing image fusion,a new method combining nonsubsampled Laplacian pyramid (NLP)and bidimensional empirical mode decomposition(BEMD)is ***,the high resolution panchromatic image (PAN)is decomposed using NLP until the approximate component and the low resolution multispectral image(MS)contain features with a similar ***,the approximation component and the MS are decomposed by BEMD,resulting in a number of bidimensional intrinsic mode functions(BIMF)and a residue *** instantaneous frequency is computed in 4 directions of the *** the positive or negative coefficients in the corresponding position,a weighted algorithm is designed for fusing the high frequency details using the instantaneous frequency and the coefficient absolute value of the BIMFs as fusion *** fused image is then obtained through inverse BEMD and *** results have illustrated the advantage of this method over the IHS,DWT andà-Trous wavelet in both spectral and spatial detail qualities.

关键词： bidimensional empirical mode decomposition nonsubsampled pyramid instantaneous frequency remote sensing image fusion

Modeling Superhydrophobic Contact Angles and Wetting Transition

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Journal of Bionic Engineering 2009年第4期6卷 335-340页

作者： Nan Gao, Yuying YanDBE, Faculty of Engineering, university of Nottingham, NGl 2RD, UK [a] DBE Faculty of Engineering University of Nottingham NG7 2RD UK

It is well known that surface roughness has a very important effect on *** Wenzel and Cassie-Baxter models,which correspond to the homogeneous and heterogeneous wetting respectively,are currently primary instructions for designing superhydrophobic ***,the particular drop shape that a drop exhibits might depend on how it is formed. A water drop can occupy multiple equilibrium states,which relate to different local minimal *** some cases,both equilibrium states can even co-exist on a same *** the apparent contact angles may vary and have different *** discuss how the Wenzel and Cassie-Baxter equations determine the homogeneous and heterogeneous wetting theoretically. Contact angle analysis on hierarchical surface structure and contact angle hysteresis has been put specific *** particular, we study the energy barrier of transition from Cassie-Baxter state to Wenzel state,based on existing achievement by previous researchers,to determine the possibility of the transition and how it can be *** has been demonstrated that surface roughness and geometry will influence the energy required for a drop to get into equilibrium,no matter it is homogeneous or heterogeneous wetting.

关键词： superhydrophobic surface contact angle wetting transition energy balance biomimetics