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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 {2., Hangzhou 310036, China 2. department of Applied mathematics, School of Mathematical Sciences, South China {2. 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.

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,{2., China 2. department of Physics, Shaoguan university, Shaoguan 512.05, China 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.

Synergistic injection of the thermosensitive hydrogel and Bi-based alloy bone cement for orthopaedic repair

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Science China(Technological Sciences) 2024年第7期67卷 2153-2163页

作者： LIU SiCong LI Lei JIANG ChanYuan WANG QianYu DENG zhongshan Key Laboratory of Cryogenic Science and Technology Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China department of Cleft Lip and Palate Plastic Surgery HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100144China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China

Low-melting-point alloys have the advantages of good biocompatibility, plasticity, and near-bone mechanical strength, making them suitable as bone defect-filling materials for direct injection into defective bone sites. However, using low-melting-point alloys for orthopedic implants poses the challenge of causing thermal damage to the surrounding bone tissue during injection. In this study, a thermosensitive hydrogel is prepared and synergistically injected into the bone defect site with BiInSn. BiInSn solidifies and releases heat during injection, while the thermosensitive hydrogel absorbs heat and transforms into a gel state,encapsulating BiInSn. Therefore, the surrounding bone tissue is effectively protected from thermal damage. When BiInSn and the thermosensitive hydrogel were injected synergistically, in vitro thermal experiments revealed that the maximum temperature of the surrounding bone tissue reached 42.. This temperature is below the 47℃ threshold, which causes permanent damage to bone tissues. In vivo experiments demonstrated that rats in the BiInSn-thermosensitive hydrogel group exhibited better recovery at the bone defect sites. These results suggest that the synergistic injection of Bi-based alloy and thermosensitive hydrogel is beneficial in reducing thermal damage to bone tissue, guiding bone tissue growth, and effectively facilitating the repair of bone defects.

关键词： bone defects thermosensitive hydrogel thermal damage to tissue bismuth-based alloy bone cement

ON THE MODULI NUMBER OF PLANE CURVE SINGULARITIES WITHONE CHARACTERISTIC PAIR

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Chinese Annals of mathematics,Series B 1999年第4期20卷 407-412页

作者： CHEN HAO(department of mathematics,{2., guangzhou 51.2.5, China) zhongshan Univ Dept Math Guangzhou 510275 Peoples R China

The author gives another linear-algebraic proof of the famous result of Zariski, Delorme,Briancon- Granger- Maisonobe about the moduli number of plane curve singularities with the same topological type as Xa + Yb = 0 (i.e.,with one characteristic pair). Since the original proof depends very much on the division theorem of Briancon, it cannot be generalized to higher dimensions. It is hopeful that the proof here will be applied to the higher dimensional cases.

关键词： Moduli number Plane curve Singularity Characteristic pair

SIMPLE OCKHAM ALGEBRAS

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Chinese Annals of mathematics,Series B 1996年第2期17卷 213-218页

作者： FANG JIE department of mathematics,{2., guangzhou 5102.1, China. zhongshan UNIV DEPT MATHGUANGZHOU 510271PEOPLES R CHINA

An algeber L is said to be simple, if its congruence lattice Con L reduces to the 2.elementchain {ω,v}. This paper describes the structure of finite simple Ockham algebras.

关键词： Ockham algebra Simple algebra Congruence lattic 2.element chain

Some properties on multivariate filter banks with a matrix factorization

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Progress in Natural Science:Materials International 2005年第2期15卷 20-30页

作者： LIAN Qiaofang1, XIAO Hongying2. and CHEN Qiuhui3(1. department of mathematics, Beijing Jiaotong {2., Beijing 100044, China 2. Institute of mathematics, Academy of mathematics and System Sciences, Chinese Academy of Sciences, Beijing 100080, China 3. department of Scientific Computing and Computer Applications, zhongshan university, guangzhou 51.2.5, China) department of mathematics Beijing Jiaotong University Beijing 100044 China. Institute of mathematics Academy of Mathematics and System Sciences Chinese Academy of Sciences Beijing 100080 China. department of Scientific Computing and Computer Applications Zhongshan University Guangzhou 510275 China

A class of multivariate filter banks with a matrix factorization has been developed by Chen et al. The main purpose of this paper is to discuss some further properties of this kind of filter bank, such as the completeness, accuracy of the corresponding scaling functions and the relationships with Daubechies' wavelets and the multi-wavelets provided by Chui and Lian. Moreover, some examples are given to show that this kind of filter bank has a higher accuracy for the scaling functions.

关键词： filter banks completeness accuracy matrix factorization

Dimension and measure theoretic entropy of a subshift in symbolic space

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Chinese Science Bulletin 1997年第14期42卷 1193-1196页

作者： CHEN Ercai and XIONG Jincheng1. department of Astronomy, Nanjing university, Nangjing 2.0093, China {2., South China Normal university, guangzhou 510631, China department of Astronomy Nanjing University Nangjing China department of mathematics South China Normal University Guangzhou China

1 Definitions and resultsWITH the development of the theory of dynamical systems and fractal geometry, one provedthat symbolic dynamics is a powerful tool to study chaos and fractals. It is useful to study thefractal characteristics of symbolic dynamics. In the present note we shall point out the relationbetween the dimension and measure theoretic entropy of any subshift in symbolic space. Weprove here that the Bowen’s formula for Hausdorff dimension holds without Markov struc-ture. A variational principle for dimension is obtained.

关键词： symbolic space subshift measure theoretic entropy dimension.

ID-WAVELETS METHOD FOR HAMMERSTEIN INTEGRAL EQUATIONS

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Journal of Computational mathematics 1998年第6期16卷 499-508页

作者： Xian-biao Wang Wei Lin (department of mathematics,{2., guangzhou 51.2.5, China) zhongshan Univ Dept Math Canton 510275 Peoples R China

The numerical solutions to the nonlinear integral equations of Hammerstein-type y(t) = f(t) + integral(0)(1)k(t, s)g(s, y(s))ds, t is an element of [0,1] are investigated. A degenerate kernel scheme basing on ID-wavelets combined with a new collocation-type method is presented. The Daubechies interval wavelets and their main properties are briefly mentioned. The rate of approximation solution converging to the exact solution is given. Finally we also give two numerical examples.

关键词： nonlinear integral equation interval wavelets degenerate kernel

T1 theorem for Besov and Triebel-Lizorkin spaces

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Science China mathematics 2005年第5期48卷 657-665页

作者： DENG Donggao & HAN Yongsheng department of mathematics,{2., guangzhou 51.2.5, China department of mathematics, Auburn university, Alabama, 36849, USA Dept. of Math. Zhongshan Univ. Guangzhou 510275 China Dept. of Math. Auburn Univ. Alabama 36849 United States

Using the discrete Calderon type reproducing formula and the PlancherelPolya characterization for the Besov and Triebel-Lizorkin spaces, the T1 theorem for the Besov and Triebel-Lizorkin spaces was proved.

关键词： T1 theorem Besov and Triebel-Lizorkin spaces Calderon reproducing formula Plancherel-Polya inequalities.