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The Juancheng chondrite──A new meteorite falling recently in china

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Chinese Science Bulletin 1998年第21期43卷 1834-1837页

作者： CHEN Yongheng 1,2. WANG Daode+2.and WANG Ruitian+31. department of chemistry, {2. Normal University, {2. 510400, china 2. {2. Institute of Geochemistry, Chinese Academy of Sciences, {2. 510640, china 3. Heze Bureau of Seismolo department of chemistry Guangzhou Normal University Guangzhou China guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou China Heze Bureau of Seismology Shandong Province Heze China

The Juancheng chondrite, a new meteorite falling recently in Juancheng County, Shandong Province, china, is classified as an H5 (S2. chondrite based on the compositions of olivine (Fa= 19.2. σ Fa=0.46) and low-Ca pyroxene (Fs=16.9, σ Fa=0.4). The plagioclase in the Juancheng chondrite is rich in CaO, indicating a relatively high metamorphic temperature the parent body underwent.

关键词： Juancheng ordinary chondrite new meteorite.

Population-size-dependent branching processes in Markovian random environments

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Chinese Science Bulletin 1998年第8期43卷 635-638页

作者： WANG Hanxing 1 and DAI Yonglong 2.1. department of Mathematics, Shanghai University, Shanghai 2.1800, china 2. department of Mathematics, Zhongshan University, guangzhou 5102.5, china department of Mathematics Shanghai University Shanghai China department of Mathematics Zhongshan University Gunngzhou China

A branching model {Z n} n≥0is considered where the offspring distribution of the population’s evolution is not only dependent on the population size, but also controlled by a Markovian environmental process {ξ n} n≥0. For this model, asymptotic behaviour is studied such as limn→∞Z n and limn→∞Z n/m n in the case that the mean m k, θof the offspring distribution converges to m>1 as the population size k grows to ∞. In the case that {ξ n} n≥0is an irreducible positive recurrent Markov chain, certain extinction (i.e. P(Z n=0 for some n)=1) and noncertain extinction (i.e. P(Z n=0 for some n)<1) are studied.

关键词： Markov chains in random environments stochastic population models branching processes.

Controlled Deposition of HAp Mimicking Tooth Enamel

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Journal of Wuhan University of Technology(Materials Science) 2005年第B12期20卷 153-155页

作者：黄微雅张渊明 department of chemistry Jinan University Guangzhou 510632 China

Chemical compositions and mierosturcture of mature human tooth enamel were investigated by XRD , FTIR and SEM to further understand the characteristics of tooth enamel. In order to obtain apatite crystals chemically and structurally similar to those in tooth enamel, biomimetic way was employed. Self-assembled monolyers terminated with-SO3 H groups were used as deposition substrates and 1.5 SBF （ the concentrations of Ca^2. and PO4^3- ions 1.5 times ttum those in simulated body fluid ） with and without 5 ppm F^- were used as soaking medium. The XRD and FTIR results showed that both the deposited fluoride-substituted hydroxyapatite （ F-HAp ） crystals in 1.5 SBF with F^- and hydroxyapatite （ HAp ） crystals in 1.5 SBF were carbonate-contain ing, mimicking human tooth enamel in chemical compositions. The SEM photos showed that needle-like F-HAp crystals had large aspect ratios and grew in bundles, which were similar to the crystals in human tooth enomel. The results provide available information on dental restoration.

关键词： tooth enamel biomimetic self assembled monolyers simulated body fluid hydroxyapatite

Microwave peak absorption frequency of liquid

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Science china(Physics,Mechanics & Astronomy) 2008年第9期51卷 1254-1263页

作者： HAN GuangZe1 & CHEN MingDong2.1 department of Physics,South china University of Technology,{2. 510640,china 2.{2. Auto College,South china University of Technology,{2. 510800,china 1. department of Physics South China University of Technology Guangzhou 510640 China 2. guangzhou Auto College South China University of Technology Guangzhou 510800 China

Microwave-assisted extraction is a new effective method which has practical ap-plications in many fields. Microwave heating is one of its physical mechanisms,and it also has the characteristic of selectivity. When the applied microwave fre-quency equals a certain absorption frequency of the material (or specific compo-nent),the material will intensively absorb microwave energy. This is also known as resonant absorption,and the frequency is called the peak absorption frequency which depends on the physical structure of the material. In this work,dynamic hy-drogen bond energy was included in molecular activation energy; with the liquid cell model,the expression of interaction energy between dipolar molecules was derived. The rotational relaxation time was gotten from the Eyring viscosity formula. Then based on the relationship between dielectric dissipation coefficient and re-laxation time,the expression of microwave peak absorption frequency as a func-tion of the material physical structure,rotational inertia and electrical dipole mo-ment of molecules was established. These theoretical formulas were applied to water and benzene,and the calculated results agree fairly well with the experi-mental data. This work can not only deepen the study of the interaction between microwave and material,but also provide a possible guide for the experiment of microwave-assisted extraction.

关键词： microwave-assisted extraction microwave heating relaxation time liquid viscosity peak absorption fre-quency

The Stamping Formability of AZ31 Magnesium Alloy Sheet Improved by Equal-channel Angular Pressing

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Journal of Wuhan University of Technology(Materials Science) 2010年第2期25卷 234-237页

作者：刘英 department of Material Science and Engineering Jinan University

Equal channel angular pressing （ECAP） processing and annealing were applied to the AZ31 magnesium alloy sheets to evaluate the potential improvement in the mechanical properties and formability. The ECAP experiment was conducted at 300 ℃ in a die having an included angle of 90o between two channels by the BCZ route with the sheets rotated by 90°about the normal axis of plate plane. The tensile tests and conical cup tests were conducted at various temperatures from 2. to 2.0 ℃. The experimental results indicated that improving the working temperatures could lead to the soft in the material and the enhancement of ductility. Comparatively, the ECAPed AZ31 alloy sheets showed the lower yield strength and smaller conical cup value （CCV） than the unECAPed counterpart in the room temperature. The difference in yield strength between them became small in the elevated temperature, but the ECAPed samples still had the smaller CCV value, implying the improved formability. The texture of the AZ31 alloy sheets could be modified by ECAP and the decrease in the yield strength and more uniform deformation realized in the material, so the formability of AZ31 alloy sheets was improved.

关键词： AZ31 magnesium alloy sheets equal-channel angular pressing mechanical properties conical cup value (CCV)

Effect of an impurity on 3-electron quantum dots in magnetic fields

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Science china(Physics,Mechanics & Astronomy) 2004年第5期47卷 521-530页

作者： LIU Yimin1,2. HUANG Gangming1 & BAO Chengguang1 1. department of Physics, Zhongshan University, guangzhou 5102.5, {2. 2. department of Physics, Shaoguan University, Shaoguan 512.05, {2. 1. department of Physics Zhongshan University 510275 Guangzhou China 2. department of Physics Shaoguan University 512005 Shaoguan China

The ground-state property of a 2.dimensional 3-electron quantum dot (QD) subjected to an external magnetic fieldB and affected by an impurity is studied. The impurity is located at thez-axis by a distanced from the plane of the dot. The evolution of the angular momentumL o and the spinS o of the ground state in accordance withB andd has been calculated, and the results are summarized and plotted in a (L o,S o) diagram. The spatial distribution of the electrons (the size and the geometric features) and the optical absorption have also been investigated. The (L o S o) diagram indicates thatL o andS o may jump whend and/orB vary. It was found that, due to the constraints arising from symmetry, each symmetric geometry is accessible only to a specific group of states having specificL o andS o.

关键词： quantum dot, ground state, charged impurity, magnetic field.

Transitional function of DG to CA3 in the hippocampus

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Progress in Natural Science:Materials International 2007年第12期17卷 1436-1444页

作者： Yan Chuankui1 and Liu Shenquan2.1. department of Mathematics, Hangzhou Normal University, Hangzhou 310036, china 2. department of Applied Mathematics, School of Mathematical Sciences, South china University of Technology, guangzhou 510640, china) department of Mathematics Hangzhou Normal University Hangzhou 310036 China department of Applied Mathematics School of Mathematical Sciences South China University of Technology Guangzhou 510640 China

Using single cell channel model, the transmission features of CA3-DG network in the hippocampus are investigated. The influence of the stimulation on discharge pattern of pyramidal neurons is analyzed, which shows that it starts with period spiking discharges, followed by period-doubling bifurcation to chaos, and period 3 discharge evolving into chaos, and ultimately a period of bursting discharges. By the synaptic model, the CA3-DG network model is constructed, which analyzes the summation of postsynaptic currents in the network, the influence of postsynaptic current on discharge rhythm as well as the mechanism of bursting discharges. The strong capacity of spatiotemporal encoding in the network indicates the features of CA3 network during the information transmission process in the hippocampus. The modeling result with time delay of the synaptic transmission is in accordance with the experimental phenomena of action potential in the hippocampus.

关键词： hippocampus CA3-DG period-doubling bifurcation chaos.

Research on Negotiating Agent Development

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Wuhan University Journal of Natural Sciences 2004年第5期9卷 633-637页

作者： WEI Ding-guo 1,2., PENG Hong 1 1.department of Computer Science, South china University of Technology, {2., Guangdong, china 2.Guangdong Commercial College, guangzhou 51032.,Guangdong, china department of Computer Science South China University of "technology Guangzhou 510630 Guangdong. China

The paper presents a flexible and effective method of development of negotiating agents. A strategy specification, which is specified by a state chart and defeasible rules, can be dynamically inserted into an agent shell incorporating a state chart interpreter and a defeasible logic inference engine, in order to yield a desirable agent. The set of desirable criteria and rules is required to be justified with different context of the application. Key words automatic negotiation - intelligence agent - defeasible logic - state chart CLC number TP 391 Foundation item: Supported by the National Natural Science Foundation of china (60173051)Biography: WEI Ding-guo (1964-), male, Associate professor, research direction: computer network protocal etc.

关键词： automatic negotiation intelligence agent defeasible logic state chart

Langmuir-Blodgett Films and Calcium Ion Coordination of Biliverdin and Its Amphiphilic Derivatives

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Chinese Chemical Letters 2001年第5期12卷 457-460页

作者： Jian Ming OUYANG department of chemistry, {2. University, guangzhou 510632 jinan Univ Dept Chem Guangzhou 510632 Peoples R China

Monolayer formation and LB film fabrication of amphiphilic derivative of biliverdin 1, diododecyl biliverdinamide [B(CONHC12.2.)(2., 2. at an air-water interface on pure water subphase and subphase containing calcium ion were investigated and compared with 1. The coordination in ordered molecular films is much different from that in bulk solution. The formation of ligand-calcium complex was confirmed by X-ray photoelectron spectroscopy.

关键词： monolayer Langmuir-Blodgett films biliverdin calcium ion