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Analysis theory of random energy of train derailment in wind

science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 751-757页

作者： CHEN RuiLin 1,2.3 , ZENG QingYuan 3 , HUANG YunQing 1 , XIANG Jun 3 , WEN Ying 3 , GUO XiaoGang 2., YIN ChangJun 2., DONG Hui 2.& ZHAO Gang 4 1 Hunan Key Laboratory for Computation and Simulation in science and engineering, Xiangtan {2., Xiangtan 411105, china 2.school of Civil engineering & Mechanics, Xiangtan {2., Xiangtan 411105, china 3 school of Civil Architecture, central south university, changsha 410075, china 4 AMEC, Toronto M5A5G7, Canada 1. Hunan Key Laboratory for Computation and Simulation in science and engineering Xiangtan University Xiangtan 411105 China2. School of Civil Engineering & Mechanics Xiangtan University Xiangtan 411105 China3. School of Civil Architecture Central South University Changsha 410075 China4. AMEC Toronto M5A5G7 Canada

Based on the analysis theory of random energy of train derailment, an analysis theory of random energy of train derailment in wind is suggested. Two methods are proposed -the time domain method and the frequency domain method of analysis theory of random energy of train derailment in wind. The curves of σ pw -v under various wind speeds are obtained through the computation. The original curve of σ p -v is expanded, which turns the analysis theory of random energy of train derailment into the all-weather theory. Train derailment condition has been established under wind action. The first and second criterions of train derailment have been proposed in light of wind action. The analysis of train derailment cases at home or abroad is made, in- cluding the first analysis of Xinjiang train derailment case encountered 13-level of gale, which explained the inevitability of train derailment. The analysis theory of random energy of train derailment in wind shows its validity and accuracy. The input energy σ pw of the transverse vibration of train-track(bridge)-wind system is linked to train speed. With the establishment of the analysis theory of random energy of train derailment in wind, It is likely to initiate an all-weather speed limit map for a train or any high-speed train.

关键词： train derailment analysis theory of random energy of train derailment analysis theory of random energy of train de- railment in wind train derailment condition in wind the criterion of train derailment in wind train derailment case

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Simulation of moving boundary of the reaction shaft in a flash smelting furnace

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Journal of central south university 2001年第3期13卷 213-218页

作者： CHEN Zhuo 1,MEI Chi 1,CHEN Hong-rong 1,MO Jiao 2.(1 Institute on Simulation and Optimization of Pyro-installation, central Sout h university,{2., china 2.science school, Beijing university of Posts and Telecommunications, Beijing 1 1. Institute on Simulation and Optimization of Pyro-installation Central South University 410083 Changsha China 2. science school Beijing University of Posts and Telecommunications 100876 Beijing China

As to solve the online monitoring of the inner temperatur e and freezing profile of the reaction shaft of flash smelting furnace, simulation of the wall in the reaction shaft in a flash smelting furnace was made through numerical computation. The computational results are very near the data got in s ite. The error of the moving boundary is approximately 3%, and that of the tempe rature is less than 5%. It is proved that the simulation software is applicable for practice to monitor the temperature and moving boundary inside the hearth on line. Based on a large number of the data computed, the relation between the cha nge of the moving boundary and inner temperature is summarized, and the great in fluence of the cooling system on the forming and stability of the moving boundar y inside the hearth is emphasized, which provide the theoretical bases for optim izing the flash smelting operation.

关键词： flash smelting furnace moving boundary numerical computation simulation

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Review on abort trajectory for manned lunar landing mission

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science china(Technological sciences) 2010年第10期53卷 2691-2698页

作者： XI XiaoNing1, HUANG WenDe2.& WANG Wei2.3 1 College of Mechatronics engineering and Automation, National university of Defense Technology, {2. 410073, china 2.College of Aerospace and material engineering, National university of Defense Technology, {2. 410073, china 3 school of Surveying and Spatial Information System, university of New south Wales, Sydney, NSW 2.52. Australia 1. College of Mechatronics engineering and Automation National University of Defense Technology Changsha 410073 China2. College of Aerospace and Material Engineering National University of Defense Technology Changsha 410073 China3. School of Surveying and Spatial Information System University of New South Wales Sydney NSW 2052 Australia

Abort trajectory is a passage that ensures the astronauts to return safely to the earth when an emergency occurs. Firstly,the essential elements of mission abort are analyzed entirely based on summarizing the existing studies. Then,abort trajectory requirement and rational selection for different flight phases of typical manned lunar mission are discussed specifically. Considering a trade-off between the two primary constrains of an abort,the return time of flight and energy requirement,a general optimizing method for mission abort is proposed. Finally,some suggestions are given for china’s future manned lunar landing mission.

关键词： manned lunar landing mission abort trajectory design free return trajectory

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Accelerating column leaching trial on copper sulfide ore

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Rare Metals 2008年第1期27卷 95-100页

作者： WANG Hongjiang WU Aixiang ZHOU Xun WANG Shaoyong ZHANG Jie Civil and Environment engineering school University of Science and Technology Beifing Beifing 100083 China school of Resource and Safety engineering Central South University Changsha 410083 China

The main measures to accelerate leaching sulfide ore are large spraying intensity,manual oxygen supply,temperature control,and acclimated *** indoor experiment accelerating sulfide ore leaching detected the temperature during leaching process,dissolvability of oxygen,bacterial concentration,Cu concentration and slag *** the same time,this paper also analyzed the effect of four factors,which are bacterial diversity cultivation stage,spraying intensity,air supply,and whether to control temperature,on the leaching efficiency of *** results indicate that the oxygen content of leach solution has a close relationship with temperature but it is rarely affected by air *** bacterial concentration preserves from 106 to 107 mL^-1,and temperature has a great effect on the bacterial activity under the condition of proper temperature and oxygen supply,and the lack of nutrition prevents the bacterial concentration from rising in the late *** relationships of the copper leaching efficiency to temperature,air feed,and spraying intensity are directly *** leaching efficiencies of the cultivated bacteria and acclimation bacteria are 1.2.and 1.4 times as large as that of the original bacteria.

关键词： accelerating leaching spraying intensity manual air supply temperature control bacterial cultivation

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Effect of Curing Procedure on the Properties of Copper-Powder-Filled Conductive Adhesives

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Journal of Wuhan university of Technology(materials {2.) 2008年第3期23卷 323-325页

作者：郑小玲游敏 College of Mechanical and material engineering China Three Gorges University

By means of testing the shear strength with single lap joint, measuring electrical resistivity for cured products and the curing strain with strain gauges, the effect of cure parameters on the properties of HT1012.conductive adhesive filled with copper powder was investigated, and the residual stress in the conductive adhesives was also estimated. The experimental results show that the properties such as shear strength of the adhesives, electrical resistivity of products as well as the residual stress of cured HT 1012.copperfitted conductive adhesive were evidently affected by curing temperature and time. The diagrams of scanning electron microscopy （SEM） and Fourier transform infrared （FT-IR） were also used to determine the properties. The higher mechanical property was achieved under the condition of curing the adhesive 3 h at 60 ℃ as the density of the hydrogen links or linkages existed in the adhesive was relatively higher and the lower electrical resistivity occurred at 80 ℃.

关键词： conductive adhesives epoxy copper-powder-filled curing procedure

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Surface and Electrical Properties of NiCr Thin Films Prepared by DC Magnetron Sputtering

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Journal of Wuhan university of Technology(materials {2.) 2008年第2期23卷 159-162页

作者： ZHOU Jicheng TIAN Li YAN Jianwu school of Physics science and Technology Central South University Changsha 410083 China

Several batches of NiCr alloy thin films with different thickness were prepared in a multi-targets magnetron sputtering apparatus by changing sputtering time while keeping sputtering target power of Ni and Cr fixed. Then the as-deposited films were characterized by energy-dispersive X-Ray spectrometer （EDX）, Atomic Force Microscope （AFM） and four-point probe （FPP） to measure surface grain size, roughness and sheet resistance. The film thickness was measured by Alpha-Step IQ Profilers. The thickness dependence of surface roughness, lateral grain size and resistivity was also studied. The experimental results show that the grain size increases with film thickness and the surface roughness reaches the order of nanometer at all film thickness. The as-deposited film resistivity decreases with film thickness.

关键词： magnetron sputtering NiCr alloy films surface morphology resistivity

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Polycomb group proteins and their roles in carcinogenesis

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Chinese science Bulletin 2012年第18期57卷 2259-2264页

作者： XIAO LanBo 1,2.3,TAO YongGuang 1,2.3,LI LiLi 1,2.3,4 & CAO Ya 1,2.31 Key Laboratory of Carcinogenesis of Ministry of Health,Xiangya school of Medicine,central {2. university,changsha 410078,china 2.Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education,Xiangya school of Medicine,central {2. university,changsha 410078,china 3 Cancer Research Institute,Xiangya school of Medicine,central {2. university,changsha 410078,china 4 Cancer Epigenetics Laboratory,State Key Laboratory in Oncology in {2. china,Chinese university of Hong Kong,Hong Kong 999077,china Key Laboratory of Carcinogenesis of Ministry of Health Xiangya School of Medicine Central South University Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education Xiangya School of Medicine Central South University Cancer Resea

In the cell nucleus,DNA is wound around histone proteins,which are then packed together to form *** can be chemically tagged by methyl and acetyl *** group (PcG) proteins attach methyl groups to genes,which block their *** is similar to the attachment of methyl groups to gene promoters by DNA methyltransferases (DNMTs).This action is directly linked with tumor initiation and metastasis via the promotion of anti-senescence and anti-apoptosis pathways,and by facilitating epithelial mesenchymal transition (EMT).Cell fate transcriptional factors (CFTFs) and long non-coding RNAs (long ncRNAs) recruit PcG proteins to the promoters of tumor suppressor genes,resulting in epigenetic gene silencing by influencing chromatin structure and DNA ***,PcG proteins are potential diagnostic markers and targets for new chemoprevention and therapeutic strategies.

关键词：组蛋白 DNA甲基转移酶基因启动子癌变非编码RNA PEG 凋亡途径抑癌基因

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Synthesis and magnetic properties of CdS/α-Fe_2._3 hierarchical nanostructures

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science china(Physics,Mechanics & Astronomy) 2009年第7期52卷 997-1002页

作者： CHEN YuJin1,2.3, SHI XiaoLing1, CAO MaoSheng1 & ZHU ChunLing4 1 school of materials {2. and engineering, Beijing Institute of Technology, Beijing 100081, china 2.Micro-Nano Technologies Research Center, Hunan university, changsha 410082. china 3 College of {2., Harbin engineering university, Harbin 150001, china 4 College of material {2. and Chemical engineering, Harbin engineering university, Harbin 150001, china 1. school of materials {2. and engineering Beijing Institute of Technology Beijing 100081 China 2. Micro-Nano Technologies Research Center Hunan University Changsha 410082 China 3. College of science Harbin Engineering University Harbin 150001 China 4. College of material science and Chemical {2. Harbin Engineering University Harbin 150001 China

CdS/α-Fe2.3 hierarchical nanostructures, where the CdS nanorods grow irregularly on the side surface of α-Fe2.3 nanorods, were synthesized via a three-step process. The diameters and lengths of CdS nanorods can be tuned by changing the ethylenediamine (EDA) and Cd ion concentrations. The magnetic investigations by superconducting quantum interference device indicate that the hierarchical nanostructures have an Morin transition at lower temperature (2.0 K) than that of the single bulk α-Fe2.3 materials (2.3 K). Importantly, the hierarchical nanostructures exhibit weakly ferromagnetic characteristics at 300 K. A sharp peak assigned to the surface trap induced emission are observed in room temperature PL spectra. Combining with the optoelectronic properties of CdS, the CdS/ α-Fe2.3 hierarchical nanostructures may be used as multi-functional materials for optoelectronic and magnetic devices.

关键词： α-Fe2.3 CdS hierarchical nanostructures magnetic properties

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Microstructural evolution of Au-Sn solder prepared by laminate rolling during annealing process

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Rare Metals 2011年第6期30卷 627-632页

作者： WEI Xiaofeng WANG Richu FENG Yan ZHU Xuewei PENG Chaoqun school of materials {2. and engineering Central South University Changsha 410083 China

The microstructural evolution and inteffacial reaction of the Au/Sn/Au/Sn/Au/Sn/Au couples were investigated during annealing at 453, 52., and 543 K for up to 2.0 h. The Au/Sn combination formed a rapid diffusion system. Even in rolled Au-Sn solder, three phases, such as AuSn, AuSn2. and AuSn4, were formed. After initial annealing at 453 K, the diffusion layers of AuSn, AuSn2. and AuSn4, which were formed after rolling, expanded gradually and then fully transformed into phase （containing Sn from 10% to 18.5%, mole fraction） and 6 （AuSn） phase. As a whole, the microstmcture of the couple was stable during annealing at 453 K. The solid-state interracial reaction was much faster at 52. K than at 453 K. After annealing at 52. K for 6 h, the AuSn, AuSn2. and AuSn4 were fully transformed into the phase and phase （AuSn）. In spite of the prolonged annealing time for up to 2.0 h, no significant change of the interfacial microstructure occurred, and the microstructure of the couple was stable during annealing at 52. K. When annealing at 543 K, however, the interfacial of Au/Sn was transformed into solid-liquid state, and the whole couple formed a eutecfic structure rapidly, causing the solder to be brittle. The study results clearly demonstrate that the service temperature of the Au-Sn solder should be lower than 543 K.

关键词： Au-Sn solders intermetallic compounds (IMCs) rolling-annealing method interfacial reaction microstructural evolution

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Hot compression deformation behavior of the Mg-Al-Y-Zn magnesium alloy

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Rare Metals 2008年第2期27卷 121-126页

作者： FANG Xiya YI Danqing WANG Bin WU Chunping ZHANG Hong school of materials {2. and engineering Central South University Changsha 410083 China

The hot deformation behavior of a Mg-Al-Y-Zn magnesium alloy was investigated by hot compressive testing on a Gleeble-1500 thermal simulator at the temperature ranging from 52. to 673 K with the strain rate varying from 0.001 to 1 s^-1. The relationships among flow stress, strain rate, and deformation temperature were analyzed, and the deformation activation energy and stress exponent were calculated. Microstructure evolution of the alloy under different conditions was examined. The results indicated that the maximum value of the flow stress increased with the decrease of deformation temperature or the increase of strain rate. Under the present deformation conditions, dynamic recrystallization （DRX） occurred in the alloy, which was the main softening mechanism during deformation at elevated temperature. The deformation temperature and strain had significant effects on the microstructure of the alloy.

关键词： Mg-Al-Y-Zn magnesium alloy thermal deformation simulation deformation activation energy dynamic recrystallization

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