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湖南大学学报（自然科学版） 2009年第S1期36卷 96-101页

作者： TANG Wen-wu1,2.WANG Han-qing1,2.1.school of energy {2. and engineering,Central South University,Changsha,Hunan 410083,china 2.school of Civil engineering,Hunan University of Technology,Zhuzhou,Hunan 412.08,china) school of energy {2. and engineering Central South University Changsha 410083 China school of Civil engineering Hunan University of Technology Zhuzhou 412008 China

This paper presented an entropy evaluation method for the influences of condense heat recovery system on the *** at the damage of the condense heat to the environment,an entropy of resource loss and an emission entropy from the condense heat recovery system in the air conditioning refrigerating machine were *** the evaluation of the entropies,we developed a new algorithm for the parameter identification,called the composite influence coefficient,based on the Least Squares Support Vector Machine *** simulation,the numerical experiments shows that the Least Squares Support Vector Machine method is one of the powerful methods for the parameter identification to compute the damage entropy of the condense heat,with the largest training error being-0.02.(the relative error being-3.56%),and the biggest test error being 0.015(the relative error being 2.5%).

关键词： air-conditioning refrigerating machine condense heat entropy evaluation LS-SVM

Glass forming ability, microstructure and magnetic property of NdAlNiCuFe alloys

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International Journal of Minerals,Metallurgy and Materials 2007年第S1期15卷 13-18页

作者： Zhi Zhang, Zhaolong Wang, Dongman Yu, and Chunling Chen school of Materials science and {2., henan polytechnic University, jiaozuo 454000, china

The glass forming ability (GFA), microstructure and magnetic property in (Nd60Al10Ni10)Cu2.-xFex (0≤ x≤ 2.) alloys were investigated by using X-ray diffraction (XRD), differential scanning calorimetry (DSC), high resolution transmission electron mi- croscopy (HRTEM) and magnetic property measurement. It is shown that the GFA of the alloys decreases with Fe content. The sam- ples for bulk cylinders with x≤10 show a distinct endothermic peak in the DSC traces due to a glass transition in the range of 42.-438 K. With further increasing Fe, the glass transition is masked by the crystallization. The microstructure of the Nd-based alloy can change progressively from full glassy state into composite state with nanocrystalline particles in the glassy matrix indicating the glass forming ability degrades with increasing Fe. The average size of nanocrystals increases with Fe and the distribution changes from homogenous to heterogeneous. The magnetic property varies from paramagnetic to hard magnetic when the Fe content increases up to about 4at% indicating that the magnetic property is related to the metastable phases.

关键词： Nd-based alloys glass forming ability microstructure magnetic properties

Analysis for twinning and slip in face-centered cubic crystals under axisymmetric co-deformation

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science china(Technological sciences) 2006年第5期49卷 521-536页

作者： CHEN Zhiyong1,2. CAI Hongnian1, ZHANG Xinming2. WANG Fuchi1 & TAN Chengwen1,3 1. school of Material science and {2., Beijing Institute of Technology, Beijing 100081, china 2. school of Material science and {2., Central South University, Changsha 410083, china 3. school of Material science and {2., Beijing University of Aeronautics and Astronautics, Beijing 100083, china 1. school of Material science and {2. Beijing Institute of Technology Beijing 100081 China 2. school of Material science and {2. Central South University Changsha 410083 China 3. school of Material science and {2. Beijing University of Aeronautics and Astronautics Beijing 100083 China

The maximum work principle of Bishop-Hill was developed to analyze the axisymmetric co-deformation in face-centered cubic crystals (f.c.c.) for twinning on {111} 112.and slip on {111} 110 systems. The influence of ξ , the ratio of critical re- solved shear stress for twinning to slip, on the yield stress states and corresponding active slip or/and twinning systems for orientations in the standard stereographic triangle of cubic crystal was investigated systematically. The Taylor factors and the anisotropy of yield strength for three important orientations [100], [110] and [111] in orientation space were analyzed. It is found that the yield strength asymmetry for the case of axisymmetric de- formation of tension and compression can be explained based on the microscopic theory of crystal plasticity. The concept of orientation factor for twinning ability was proposed and the deformation mechanism map in the orientation space was established for the case of axisymmetric deformation. The deformation texture formation and development of f.c.c. crystals with low stacking fault energy for axisymmetric tension can be explained qualita- tively on the basis of analyzed results.

关键词： twinning slip face-centered cubic crystals axisymmetric co-deformation Bishop-Hill maximum work principle yield strength anisotropy

Mechanical Hysteresis of Hexagonal Boron Nitride

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Journal of Wuhan University of Technology(Materials science) 2011年第5期26卷 935-938页

作者：周爱国 school of Materials science and {2. Henan Polytechnic University

Hexagonal boron nitride （h-BN） is an important structural material with layered *** of the plastic anisotropy,this material shows obvious mechanical hysteresis （nonlinear elastic deformation）.There are hysteretic loops at the cyclical load-unload stress-strain curves of ***,two hot-pressed h-BN cylinders with different textures were *** mechanical hysteresis is heavily *** area of hysteretic loop is linearly related with the square of loading *** minor loops attached on the hysteretic loops with the same extreme stresses have congruent *** can be concluded that the mechanical hysteresis of h-BN can be explained by a Kink Nonlinear Elastic model developed from the study of a ternary carbide Ti3SiC2.

关键词： boron nitride nonlinear elastic deformation kink band texture

Surface Nanocrystallization of Magnesium Alloy AZ91D by High-energy Shot Peening

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Journal of Wuhan University of Technology(Materials science) 2009年第4期24卷 515-519页

作者：张津 school of Materials science & {2. University of Science and Technology Beijing College of Materials science & engineering Chongqing University of Technology

High-energy shot peening （HESP）, a method to produce severe plastic deformation by high velocity flying balls, was applied on die cast magnesium alloy AZ91D. Effects of surface nanocrystallization by HESP and heat treatment at different temperatures were investigated. The mi- crostructure evolution was conducted using X-ray diffraction （XRD） and field emission scanning electronic microscopy （FESEM）. The hardness was measured by microhardness tester. The experimental results show that surface nanocrystrallization of AZ91D obtained by HESP would lead to the increase of microhardness. Low temperature heated at 100℃ for 1 h do not change the property obviously. However, both the microstructure and microhardness vary greatly after heat treatment at 400℃ for 1 h.

关键词： AZ91 D surface nanocrystallization HESP microhardnss corrosion resistance

Diffusion and Oxidation Wear of PCBN Tool based on Thermodynamics

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Journal of Wuhan University of Technology(Materials science) 2010年第2期25卷 265-271页

作者：邵芳 Binzhou Vacational College school of Mechanical engineering Shandong University

The rules of diffusion wear and oxidation wear for PCBN cutting tools were analyzed based on thermodynamics theory. Dissolution concentrations in typical normal workpice materials of PCBN tool material at different temperature were then calculated. Diffusion reaction rules in high temperature were developed and analyzed using the Gibbs free energy criterion. The machining tests were conducted using the PCBN tools at different cutting speeds of 50, 95,100 and 180 m/min, feed of 0.1, 0.2.and depth of cut of 0.1, 0.8, 1, and 1.5 mm respectively on a PUMA300LM numerically-controlled lathe. It was found that the theoretical results were uniform with the experimental data, and the results will provide useful references for tool material design and selection.

关键词： thermodynamics PCBN tool diffusion wear oxidation wear

Theoretical studies on the possible conformers and properties of tetranitrodiazidoacetylhexaazaisowurtzitane (TNDAIW)

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science china Chemistry 2004年第5期47卷 414-419页

作者： WU Yukai1, OU Yuxiang1, LIU Zhiguo1,2., LIU Jinquan1, MENG Zheng1 & CHEN Boren1 1. school of Materials science and {2., Beijing Institute of Technology, Beijing 100081, china 2. school of Chemistry and Chemical {2., henan University, Kaifeng 475001, china 1. school of Materials science and {2. Beijing Institute of Technology 100081 Beijing China 2. school of Chemistry and Chemical engineering Henan University 475001 Kaifeng China

Tetranitrodiazidoacetylhexaazaisowurtzitane (TNDAIW) is a novel polyazapolycyclic caged polyazidonitramine explosive first synthesized in our laboratory. All of the possible con- formers of TNDAIW are optimized using both the AM1 and PM3 methods. TNDAIW is predicted to have more polymorphs than hexanitrohexaazoisowurtzitane (CL-2.). The HF/6-31G(d) level of theory is used to investigate the lowest energy structures of D-TNDAIW for both AM1 and PM3. The possible conformers of TNDAIW are predicted to be more stable than epsilon-CL-2. based on the N-NO2.bond lengths. The impact and shock sensitivities of both the possible DA- and DP-TNDAIW are lower than the corresponding ones of epsilon-CL-2.. TNDAIW with the possible conformers is estimated to be a promising novel high energy density explosive.

关键词： tetranitrodiazidoacetylhexaazaisowurtzitane, molecular modeling, impact and shock sensitivities.

A computer simulation of nucleation and growth of thin films

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science china(Physics,Mechanics & Astronomy) 2004年第4期47卷 442-451页

作者： ZHENG Xiaoping1,ZHANG Peifeng2.HE Deyan2.LIU Jun2. MA Jiantai3 1. Key Laboratory of Opto-Electronic Technology and Intelligent Control, Ministry of Education, Lanzhou Jiaotong University, Lanzhou 730070, china 2. school of Physical {2. and Technology, Lanzhou University, Lanzhou 730000, china 3. school of Chemistry and Chemistry engineering, Lanzhou University, Lanzhou 730000, china 1. Key Laboratory of Opto-Electronic Technology and Intelligent Control Ministry of Education Lanzhou Jiaotong University 730070 Lanzhou China 2. school of Physical science and Technology Lanzhou University 730000 Lanzhou China 3. school of Chemistry and Chemistry engineering Lanzhou University 730000 Lanzhou China

A three-dimensional kinetic Monte Carlo technique has been developed for simulating the nucleation and growth of thin films. This model involves incident atom attachment, surface diffusion of the atoms on the growing surface and atom detachment from the growing surface. It takes some new effects into account, such as a significant improvement in calculation of activation energy for the atom diffusion, which renders the model more reasonable. In addition three optimum temperatures and the consistency of their dependence on deposition rate have been found out; the dependence of the surface roughness and relative density on the deposition rate has been discussed; and the approximation of freezing neighbour atoms and periodic boundary conditions has been applied.

关键词： Monte Carlo, thin film, nucleation, surface roughness, relative density.

Electrical Breakdown Characteristic of Nanostructured W-Cu Contacts Materials

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Journal of Wuhan University of Technology(Materials science) 2006年第4期21卷 32-35页

作者：王俊勃 school of Mechanical and Electrical engineering Xi'an Polytechnic UniversityXi'an 710048 ChinaSchool of Science Xi'an Jiaotong University Xi'an 710049China

Nanostructured （ NS ）W-Cu composite powder was prepared by mechanical alloying （ MA ）, and nanostructared bulk of W-Cu contact material was fabricated by hot press sintering in an electrical vacuum furnace. The rnicrostructure, electric conductivity, hardness and break down voltage of NS W- Cu alloys were measured and compared to those of conventional W-Cu alloys prepared by powder metallurg＇y. The experimental results show that microstructural refinement and uniformity can improve the breakdown behavior and the electric arc stability of nanostructared W- Cu contacts materials. Also, the wanostructured W- Cu contact material shows the characteristic of spreading electric arcs, which is of benefit to electric arc erosion.

关键词： nanostructured materials W-Cu alloy electrical breakdown

Single-step-lag OOSM algorithm based on unscented transformation

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science china(Information sciences) 2011年第3期54卷 664-673页

作者： CHEN JinGuang 1,2., LI Jie 1 & GAO XinBo 1 1 school of Electronic engineering, Xidian University, Xi’an 710071,{2. 2.school of Computer science, Xi’an polytechnic University, Xi’an 710048,{2. 1. school of Electronic engineering Xidian University Xi’an 710071 China2. School of Computer Science Xi’an Polytechnic University Xi’an 710048 China

Aiming at the out-of-sequence measurement (OOSM) problem, the update equations of the nonlinear single-step-lag OOSM are derived based on the existing methods. By introducing the unscented transformation (UT), the covariance between state vector and corresponding measurement vector are computed such that the single-step-lag OOSM can be effectively solved under the nonlinear Gaussian system with nonlinear measurement equation and linear dynamic equation. Furthermore, a single-step-lag OOSM fusion algorithm based on UT is presented to confront the problem of the single-step-lag OOSM in multi-sensor system. The proposed algorithm has some advantages over the EKF A1 based on the extended Kalman filter frame and the optimal method without lags. For example, it can be used when the Jacobian matrix or the Hessian matrix of nonlinear measurement equation is nonexistent; its filtering performance is better; and its complexity has the same order of magnitude as that of the EKF A1 algorithm.

关键词： state estimation nonlinear filtering out-of-sequence measurements unscented transformation data fusion