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Characteristic atom arranging crystallogphy of alloy phases for Au-Cu system

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Science china(Technological Sciences) 2011年第6期54卷 1560-1567页

作者： XIE YouQing1,2,3,LIU XinBi1,2,3,PENG HongJian4,NIE YaoZhuang5,LI XiaoBo6 & LI YanFen1,2,3 1 school of Materials Science and Engineering,central south university,changsha 410083.china 2 Powder Metallurgy Research Institute,central south university,changsha 410083.china 3 State Key Laboratory of Powder Metallurgy,central south university,changsha 410083.china 4 school of Chemistry and Chemical Engineering,central south university,changsha 410083.china 5 school of Physical Science and Technique,central south university,changsha,410083.china 6 College of Mechanical Engineering,Xiangtan university,Xiangtan 411105,china school of Materials Science and Engineering Central South University Changsha China Powder Metallurgy Research Institute Central South University Changsha China State Key Laboratory of Powder Metallurgy Central South University Changsha China school of Chemistry and Chemical Engineering Central South University Changsha China school of Physical Science and Technique Central South University Changsha China College of Mechanical Engineering Xiangtan University Xiangtan China

In this paper,it is pointed out that the descriptions of alloy phase structures are dependent on structural unit *** the systematic science of alloys(SSA),the alloy phase structures are described by means of the symmetry element sequence combining with characteristic atom *** is named the characteristic atom arranging structure,which can display the characteristic atoms at the lattice sites and the micro-inhomogeneity,besides the *** characteristic atom has its own characters:neighboring configuration,potential energy,volume and electronic *** micro-inhomogeneity of alloy phases can be described by concentrations and short-range ordered parameters of characteristic *** differences between the electronic structures of alloy phases and electronic structures of characteristic atoms in the alloy phases are also discussed.

关键词： systematic science of alloys Au-Cu system alloy phase structure micro-inhomogeneity

Relaxed resource advance reservation policy in grid computing

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The Journal of china Universities of Posts and Telecommunications 2009年第2期16卷 108-113页

作者： XIAO Peng HU Zhi-gang school of Information Science and Engineering,central south university,changsha 410083.china school of Information Science and Engineering Central South University Changsha 410083 China

The advance reservation technique has been widely applied in many grid systems to provide end-to-end quality of service （QoS）. However, it will result in low resource utilization rate and high rejection rate when the reservation rate is high. To mitigate these negative effects brought about by advance reservation, a relaxed advance reservation policy is proposed, which allows accepting new reservation requests that overlap the existing reservations under certain conditions. Both the benefits and the risks of the proposed policy are presented theoretically. The experimental results show that the policy can achieve a higher resource utilization rate and lower rejection rate compared to the conventional reservation policy and backfilling technique. In addition, the policy shows better adaptation when the grid systems are in the presence of a high reservation rate.

关键词： grid computing advance reservation reservation violation computing economy

Upgrading graphite by flotation at Bogala Mines in Sri Lanka

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Journal of central south university 2001年第3期13卷 193-196页

作者： M.R.Salgado (central south university, changsha 410083. china) central south university Changsha China

Graphite is naturally floatable due to its hydrophobic pro pe rty and also soft and smears on other gangue particles, rendering the gangue mor e or less floatable too. Due to this reason it is important to concentrate on ar eas such as suitable flotation reagents, depression agents, pH modifiers, and pa rticle size to be fed during the process. The paper surveys and analyses the sui table particle size to be fed to achieve high-grade concentrate. According to t h e work carried out the author suggested the ideal cost effective flotation f low sheet for improved results at Bogala Mines in Sri Lanka.

关键词： graphite flotation process reagent carbon percentage

MASS TRANSFER TO LIQUID-LIQUID INTERFACE

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Acta Metallurgica Sinica(English Letters) 1996年第2期9卷 151-156页

作者： LI Xinhai YIN Zhoulan(central-south university of Technology,changsha 410083.china) central-south Univ of Technology Changsha China

Experiments have been done on mass transfer to a liquid-liquid interface on which inert gas bubbles are *** simulate the pyrometallurgy system of melten slag-metal(or matte),aqueous solution-mercury(or zinc amalgam) system was *** mass transfer coefficients of indicator ions as a function of bubble parameters have been *** experimental results show satisfactory agreement with the mass transfer model proposed Previously.

关键词： mass transfer gas bubble liquid-liquid interface

Heat transfer analysis for the roller shell under the condition of periodic thermal shock

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Journal of university of Science and Technology Beijing 2003年第6期10卷 44-47页

作者： Lihua Zhan and Xiaoqian LiCollege of Electro-mechanical Engineering, central south university, changsha 410083. china Coll. of Electro-Mech. Eng. Central South Univ. Changsha 410083 China

According to the actual working conditions of roller shell in the process ofcontinuous roll casting, the Fourier heat transfer law is used to conduct the simulating analysisfor the temperature distribution of the roller shell under the condition of periodic thermal *** temperature variation law inside the roller shell is studied during the process of continuousroll casting, and the steady temperature distributions of the roller shell at different castingvelocities have been obtained when the thermal contact conductance between the roller shell and thecasting strip is considered.

关键词： roller shell thermal contact conductance (TCC) periodic thermal shock

Ti/Al_2O_3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

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Journal of Materials Science & Technology 1999年第3期15卷 271-275页

作者： Yimin LI(Powder Metallurgy Research Institute, central-south university of Technology, changsha 410083. china)Ziqiao ZHENG(Department of Materials Science and Engineering, central-south university of Technology, changsha 410083. china) Powder Metallurgy Research Institute Central-South University of Technology Changsha 410083 China Department of Materials Science and Engineering Central-South University of Technology Changsha 410083 China

Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one

关键词： Al SHS Ti/Al2O3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process

Effect of aluminum-containing additives on the reactivity in air and CO_2 of carbon anode for aluminum electrolysis

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Rare Metals 2004年第2期23卷 109-114页

作者： LAI Yanqing LI Jie LI Qingyu DING Fengqi school of Metalling Science and Engineering, central south university, changsha 410083. china school of Metallurgy Science and Engineering Central South University Changsha 410083

Airburn reaction and carboxy reaction result in the excess consumption ofcarbon anode in aluminum electrolysis. To reduce the excess carbon consumption, carbon anode wasdoped with aluminum-containing additives, such as Al, Al_4C_3, AlF_3 and Al_2O_3. Their reactivityin air and CO_2 was determined with an isothermal-gravimetric method to study the effect ofaluminum-containing additives on the reactivity in air and CO_2 of carbon anode. Results shown thatthe airburn reactivity at 450℃ and carboxy reactivity at 970℃ of carbon anode both decreased withAl-containing additives adding, while shown a minimum with the amount of Al_4C_3, AlF_3 and Al_2O_3increasing. However, all Al-containing additives increase the airburn reactivity at 550℃ of carbonanodes. Coke yield measurement and XRD examination with aluminum containing additives doped pitchcokes revealed that the effect of Al-containing additives on the airburn reactivity and carboxyreactivity of carbon anode would result from chemical factors and structural factors.

关键词： aluminum electrolysis aluminum-containing additives reactivity carbonanode

Controllable synthesis of Ni-catalyzed tetragonal tungsten nanowires via chemical vapor deposition

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Progress in Natural Science:Materials International 2012年第5期22卷 514-519页

作者： Chao Wang a,Yuehui He a,Chaoqun Peng b,Shiliang Wang a,c,Xinli Liu a a State Key Laboratory of Powder Metallurgy,central south university,changsha 410083.china b school of Material Science and Engineering,central south university,changsha 410083.china c school of Physics Science and Technology,central south university,changsha 410083.china State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China school of Material Science and Engineering Central South University Changsha 410083 China school of Physics Science and Technology Central South University Changsha 410083 China

Tetragonal single-crystal tungsten nanowires were successfully synthesized by chemical vapor deposition(CVD) catalyzed by Ni *** influences of the catalysts,temperature and growth time on the formation of the nanowires were *** was found that the tetragonal tungsten nanowires(WNWs) arrays were obtained by deterministic growth from the ordered Ni catalyst particles with one-to-one relation in size and position between the catalysts and *** large-scale tungsten nanowire arrays were synthesized at the low temperature of 950℃.Samples were characterized by X-ray diffraction(XRD),field-emission scanning electron microscopy(FE-SEM),transmission electron microscopy(TEM) and high-resolution transmission electron microscopy(HRTEM).Increasing growth time at 950℃,the tip of the WNWs changed from four(211) planes to four(110) *** controls of the orientation and structure of WNWs arrays were important for adjusting their properties to satisfy different requirements of potential nanodevices.

关键词： Tungsten nanowires Ni catalysts Chemical vapor deposition Nanostructures

Mass Concentration of Particles (PM10) in Urban Environment of changsha,china

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湖南大学学报（自然科学版） 2009年第S1期36卷 5-9页

作者： TANG Meng,DENG Qi-hong,WANG Qi(school of Energy Science & Engineering,central south university,changsha,Hunan 410083.china) school of Energy Science and Engineering Central South University Changsha 410083 China

Continuous measurement of ambient PM10 was performed by TEOM at a university campus for about one year from 20 November 2007 to 29 October 2008 in changsha city of Hunan *** PM10 and PM2.5 concentration were measured by DustTrak simultaneously in order to describe the difference in concentration level and daily variations of particle mass concentration between different seasons,and to survey the influence of ambient particle on indoor air *** the survey period,the annual average PM10 concentration was found to be 117.63 μg/m3,with a mean value 121.88 μg/m3 in winter and 111.50 μg/m3 in *** temporal trend changed quickly from time to time,and the peak values were found in rush hours and in the *** PM10 showed a good correlation with indoor PM10 and outdoor PM2.5 but not with indoor *** results showed that PM10 was influenced by local source(such as traffic or fuel burning)and regional *** correlation analysis has shown that ambient PM10 contributes substantial fraction to indoor PM10 but not to indoor PM2.5,which indicates other source may exist in the indoor environment.

关键词： particle mass concentration human activity relationship