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Optimization of thermomechanical processes in Cu-Cr-Zr lead frame alloy using neural networks and genetic algorithms

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Science China(Technological Sciences) 2005年第5期48卷 510-520页

作者： SU Juanhua1,2. LIU Ping2. DONG Qiming2.& LI Hejun1 1. college of Materials Science and engineering, Northwestern Polytechnical University, Xi’an 710072. China 2. college of Materials Science and engineering, Henan University of Science and Technology, Luoyang 471003, China 1. college of Materials Science and engineering Northwestern Polytechnical University 710072 Xi’an China 2. college of Materials Science and engineering Henan University of Science and Technology 471003 Luoyang China

The thermomechanical treatment process is effective in enhancing the properties of the lead frame copper alloy. In this study, an optimal pattern of the thermomechanical processes for Cu-Cr-Zr was investegated using an intelligent control technique consisting of neural networks and genetic algorithms. The input parameters of the artificial neural network (ANN) are the reduction ratio of cold rolling, aging temperature and aging time. The outputs of the ANN model are the two most important properties of hardness and conductivity. Based on the successfully trained ANN model, genetic algorithms (GA) are used to optimize the input parameters of the model and select perfect combinations of thermomechanical processing parameters and properties. The good generalization performance and optimized results of the integrated model are achieved.

关键词： Cu-Cr-Zr alloy, thermomechanical processing optimization, artificial neural network, genetic algorithms.

Electrochemical Characterization of Surface-modified LiMn_2._4 Cathode Materials for Li-ion Batteries

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Journal of Wuhan University of Technology(Materials Science) 2006年第4期21卷 56-59页

作者：禹筱元 college of Science South China Agricultural University Guangzhou 510642ChinaSchool of Physics & Engineering Sun Yat-sen University Guangzhou 510275China

To improve the performance, the surface of 12.n2.4 was coated with very fine MgO , Al2.3 and ZnO by solgel method, respectively. The structure and morphology of the coated materials were investigated by X-ray diffraction （ XRD ）, X-ray photoelectron spectroscopy （ XPS ） and scanning electron microscopy （SEM）. The charge and discharge performance of uncoated and surfnce modified 12.n2.4 spinel at 2.℃ and 55 ℃ were tested, using a voltage window of 3.0-4.35 V and a current deasity of 0. 1 C rate. There is a slight decrease in the initial discharge capacity relative to that of uncoated UMn2.O4, bat the cycle ability of 12.12.n2.4 coated by metal-oxide has remarkably been improved. The EIS measuremeuts of uncoated and Al2.3 -coated 12.n2.4 were carried out by a model 2.3 A potentiostatl galvanistat controUed by a computer using M2.0 software, and using a freqnency response analyzer （ Zsimpwin ） combined with a potentiostate （ PAR 2.3）. Coaseqnently, the reason for the improved cycle properties is that the surface modification reduces the dissolution of Mn , which results from the suppression of the electrolyte decomposition, and suppresses the formation of passivation film that acts as an electronic insulating layer. In conclusion, the use of surface modification is an effective way to improve the electrochemical performance of 12.n2.4 cathode material for lithium batteries.

关键词： lithium-ion batteries surface modification metal-oxide coating: 12.n2.4 cathode

A new orthogonality relationship for orthotropic thin plate theory and its variational principle

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Science China(Physics,Mechanics & Astronomy) 2005年第3期48卷 371-380页

作者： LUO Jianhui 1 , LONG Yuqiu 2.& LIU Guangdong 1 1. college of Civil engineering, Hunan University, Changsha 410082. China 2. Department of Civil engineering, Tsinghua University, Beijing 100084, China 1. college of Civil engineering Hunan University 410082 Changsha China 2. Department of Civil engineering Tsinghua University 100084 Beijing China

The thought how dual vectors are constructed in a new orthogonality relationship for theory of elasticity is generalized into orthotropic thin plate bending problems by using the analogy theory between plane elasticity problems and plate bending problems. Dual differential equations are directly obtained by using a mixed variables method. A dual differential matrix to be derived possesses a peculiarity of which principal diagonal sub-matrixes are zero matrixes. Two independently and symmetrically orthogonality sub-relationships are discovered. By using the integral form for elastic bending theory of orthotropic thin plate the orthogonality relationship is demonstrated. By selecting felicitous dual vectors a new orthogonality relationship for theory of elasticity can be generalized into elastic bending theory of orthotropic thin plate. By using the integral form a variational principle which is relative to differential form and a whole function expression are proposed.

关键词： theory of elasticity, thin plate theory, dual vectors, orthogonality relationship, orthotropic, variational principle.

A Series Piezoelectric Quartz Crystal Response Kinetics for *** Growth in the Presence of Cu(Ⅱ)

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Journal of Central South University 2000年第1期12卷 15-19页

作者： CHAI Li yuan 1,2.,WEI Wan zhi 2.YAO Shou zhuo 2.1. Department of Metallurgical Science and engineering, Central South University of Technology, Changsha 410083, China 2. college of Chemistry and Chemical engineering, Hunan University, Changsha 1. Department of Metallurgical Science and engineering Central South University of Technology 410083 Changsha China 2. college of Chemistry and Chemical engineering Hunan University 410082 Changsha China

The kinetics on the growth of *** in the presence of Cu(Ⅱ) was studied using of series piezoelectric quartz crystal (SPQC). Arsenic ion inhibits the growth of *** , which is consistent with the previous results by other measuring methods. This further demonstrates that the SPQC can monitor the chemical activity of *** growth. Cupric ion accelerates the growth of *** . The mechanism was discussed, i. e., copper promotes the protein enzyme of *** , rusticyanin, to form over the range of cupric ion concentration studied. The reaction order of cupric ion in accelerating the bacterial growth is 0.067. The growth of *** is dependent on temperature, the apparent reaction activation energy decreases from 2..56 kJ/mol to 18.32.kJ/mol because of the addition of 10 mg/L Cu(Ⅱ) to the bacterial growth solution of pH 2.0 at initial inoculum of 10%.

关键词： series piezoelectric quartz crystal T.ferrooxidans growth kinetics sigmoid curve cupric ion

A temporal framework for building up of healthy soils

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Frontiers of Agricultural Science and engineering 2024年第2期11卷 292-296页

作者： Junling ZHANG Jiangzhou ZHANG Yunlong ZHANG guangzhou WANG State Key Laboratory of Nutrient Use and Management College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources College of GrasslandResources and EnvironmentInner Mongolia Agricultural UniversityHohhot 010018China Key Laboratory of Grassland Management and Utilization Ministry of Agriculture and Rural Affairs of the People’s Republic of ChinaCollege of Grassland Science and TechnologyChina Agricultural UniversityBeijing 100193China

Healthy soils are vital for the diverse services provided by ecosystems to human society~[1], such as provisioning(food,fiber, timber, and fuel), regulation(climate, disease, and natural hazards), waste treatment, nutrient cycling, and cultural services. Soil has a three phase system and the interactions between soil chemical, biological, and physical attributes determine functions(hydraulic, thermal, and gas fluxes).

关键词： soils soil cycling

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

Silylated and acetylated β-cyclodextrins for gas chromatographic stationary phases

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Journal of Central South University of Technology 2001年第4期8卷 239-243页

作者： TANG Ke wen 1,2.,YI Jian ming 2.ZHOU Chun shan 1,ZHONG Shi an 1 (1. college of Chemistry and Chemical engineering, Central South University, Changsha 410083, China 2. college of Chemistry and Chemical engineering, Yueyang Normal University 1. college of Chemistry and Chemical engineering Central South University 410083 Changsha China 2. college of Chemistry and Chemical engineering Yueyang Normal University 414000 Yueyang China

Two new chiral stationary phases, 2.3 di O acetyl 6 O trimethylsilyl β cyclodextrin (DATBCD) and 2.6 di O trimethylsilyl 3 O acetyl β cyclodextrin(DTABCD), were synthesized, their structures were identified by means of infrared and NMR spectra. Capillary columns were coated with the two stationary phases by dynamic method. The chromatographic properties, and enantiomers separation, such as ketone, esters, alcohols and olefines, were investigated on the silylated and acetylated β cyclodextrin stationary phases. The experimental results show that the silylated and acetylated β cyclodextrins are suitable to be used as capillary gas chromatographic stationary phases, the relative polarity of DATBCD and DTABCD stationary phases is respectively 4143 and 392., the column efficiencies are respectively 3084 and 4198, and DATBCD is of stronger enantioselectivity than DTABCD, capacity factor of the first eluted enantiomer ( k 1) and separation factor(α)of α phenylethanol on DATBCD stationary phase are respectively 8.2. and 1.019.

关键词： capillary gas chromatography silylated and acetylated β-cyclodextrins enantiomeric separation

Fracture analysis of a functionally graded interfacial zone between two dissimilar homogeneous materials

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Science China(Physics,Mechanics & Astronomy) 2006年第5期49卷 540-552页

作者： CHENG Zhanqi1,2.& ZHONG Zheng1 1. School of Aerospace engineering and Applied mechanics, Tongji University, Shanghai 2.0092. China 2. college of Civil engineering, Zhengzhou University, Zhengzhou 450002. China 1. School of Aerospace engineering and Applied mechanics Tongji University Shanghai 200092 China 2. college of Civil engineering Zhengzhou University Zhengzhou 450002 China

In this paper the plane elasticity problem for a functionally graded interfacial zone containing a crack between two dissimilar homogeneous materials has been considered. It is assumed that in the interfacial zone the reciprocal of the shear modulus is a linear function of the coordinate, while Possion’s ratio keeps constant. By utilizing the Fourier transformation technique and the transfer matrix method, the mixed boundary problem is reduced to a system of singular integral equations that are solved numerically. The influences of the geometric parameters and the graded parameter on the stress intensity factors are investigated. The numerical results show that the graded parameters, the thickness of interfacial zone, the crack size and location have significant effects on the stress intensity factors.

关键词： functionally graded material interfacial zone fracture stress intensity factor

Encapsulation of inorganic particles by dispersion polymerization through ultrasonic irradiation

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Science China Chemistry 2005年第6期48卷 545-552页

作者： ZHANG Kai1,2. FU Qiang1, HUANG Yuhong2.& ZHOU Dehui2.1. college of Polymer Science and engineering, Sichuan University, Chengdu 610065, China 2. Institute of Structure Mechanics, China Academy of engineering Physics, Mianyang 62.900, China 1. college of Polymer Science and engineering Sichuan University 610065 Chengdu China 2. Institute of Structure Mechanics China Academy of Engineering Physics 621900 Mianyang China

The nano-silica/polystyrene composite particles were prepared and characterized according to the following steps. First, the nano-silica particles were pretreated with surfactants under ultrasonic field. Second, the dispersion polymerization of styrene in a water/ethanol (1/6, weight ratio) medium, with poly(N-vinyl pyrrolidone) (PVP) as stabilizer and 2.2.-azobisizobu- tyronitrile (AIBN) as initiator in the presence of nano-silica particles was initiated with N2.purging through ultrasonic irradiation by taking its advantages of multieffect, i.e. dispersion, crushing, activation, and initiation. Finally, the polymerization kinetics characteristics were studied, and the encapsulation of composite particles was investigated with optical microscope, SEM, TEM, FTIR, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).

关键词： composite particle, dispersion polymerization, ultrasonic irradiation.