检索结果-南通市图书馆

Electrophysiological research of synapse formation from beginning to maturity

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第1期43卷 55-59页

作者： XIE Zuoping and ZHENG Yufang State Key Laboratory of Biomembrane and Membrane Biotechnique department of Biological sciences and Biotechnology, tsinghua university, beijing {4. China State Key Laboratory of Biomembrane and Membrane Biotechnique Tsinghua University Beijing China department of Biological sciences and Biotechnology Tsinghua University Beijing China

The development of synapses is an important question in neurobiology. We employ patchclamp technique to record MEPCs and EPCs of myoballs in Xenopus cell culture. The rate of EPC/MEPC is related with synapses maturation. Accordingly, we define the mature synapses as those whose rate of presynaptic membrane’s EPC to MEPC is more than 8. The process of maturation needs about 2-5 h after neurites contact with myoballs. We divide the development of synapses into three stages: young, developing and mature. The neurotransmitters stack gradually and increase by hundreds of times along with young synapses growing into maturity. So the process of synapses maturation should include presynaptic membrane specialization, postsynaptic membrane specialization and neurotransmitters stack.

关键词： definition of mature synapse α latrotoxin (α LTX) neurotransmitter stack.

Multiparty quantum secret sharing of classical and quantum messages

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第1期17卷 26-31页

作者： CHEN Pan, DENG Fuguo and LONG Guilu ( Key Laboratory for Quantum Information and Measurements, and department of Physics, tsinghua university, beijing 100084. China Key Laboratory of Beam Technology and Material Modification, MOE, Institute of Low Energy Nuclear Physics, and department of Material Science and Engineering, beijing Normal university, beijing 100875, China beijing Radiation Center, beijing 100875, China Key Laboratory for Atomic and Molecular Nano-sciences, tsinghua university, beijing 100084. China) [a]Key Laboratory for Quantum Information and Measurements and Department of Physics Tsinghua University Beijing China [b]Key Laboratory of Beam Technology and Material Modification MOE Institute of Low Energy Nuclear Physics and Department of Material Science and Engineering Beijing Normal University Beijing China [c]beijing Radiation Center Beijing China [d]Key Laboratory for Atomic and Molecular Nano-sciences Tsinghua University Beijing China

A scheme for multiparty quantum secret sharing of classical and quantum messages is proposed by using entanglement swapping. This scheme can distribute not only the classical information but also the quantum informati... 详细信息

关键词： quantum secret sharing classical message quantum message EPR pair.

Closed and endoreversible chemical oscillation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1994年第3期12卷 199-205页

作者： LI, Ru-Shengdepartment of Chemistry, tsinghua university, beijing 100084. China department of Chemistry Tsinghua University Beijing 100084 China

Based on a simple nonideal chemical reaction model, the closed system with reversible nonideal reactions and illumination is shown to be able to exhibit sustained oscillation. The essential points in the occurrence of such oscillations are the nonideality of reacting media, which gives rise to multiple chemical equilibria, and the energy flow through illumination and heat conduction, which gives rise to spontaneous transitions repeatedly between the multiple equilibrium states. During the oscillation, reacting media undergo only reversible chemical transformation and all irreversibilities are restricted to the coupling of the system to external world. This oscillation provides an example of the so-called endoreversible machine and a possible way to convert radiation energy of the light directly into mechanical energy.

关键词： Chemical oscillation closed system nonideality endoreversible machine illumination.

Fractal Characteristics of Round Jets in Steady Crossflow

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 1998年第3期3卷 183-186页

作者： Yuhang LI Chaoquan CHEN and Chunbo JIANG(Hydraulic department, tsinghua university, beijing 100084. China) Hydraulic department Tsinghua University Beijing 100084 China

The fractal dimensions of turbulent round jets in steady crossflow has beenanalyzed by using planar laser-induced fluorescence (PLIF) method. The relation betweenthe fractal dimension and the momentum ratio, the variation of the fractal dimension withthe elevation of jet and the dilution have been investigated. The comparison of the fractalcharacteristics between the multiple jets and the signal jet has been carried out.

关键词： steady crossflow turbulent jet measurement of fractal dimension

Analysis of finite-element-based methods for reducing the ill-posedness in the reconstruction of fluorescence molecular tomography

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2009年第4期19卷 501-509页

作者： Zhun Xu, Jing Bai department of Biomedical Engineering, School of Medicine, tsinghua university, beijing 100084. China [a]department of Biomedical Engineering School of Medicine Tsinghua University Beijing 100084 China

The major issue in reconstruction of optical imaging might be the ill-posedness of the problem. In this paper, four different algorithms, including singular value decomposition (SVD), the truncated SVD, Tikhonov regularization and adaptive regularization, are analyzed and applied for solving the matrix equation generated from diffuse equation based on finite-element method in fluorescence molecular tomography. Results illustrate the need for either imposition of regularization term or elimination of too small singular values in reducing the illposedness. The results also suggest that the adaptive-regularization method offers superior performance in the reconstruction among the four methods in most cases even if the initially selected regularization parameter is not optimal, thus providing the convenience for the reconstruction.

关键词： Fluorescence molecular tomography Reconstruction Ill-posedness The truncated SVD Adaptive regularization

A normalized thoracic coordinate system for atlas mapping in 3D CT images

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2008年第1期18卷 111-117页

作者： Hongkai Wang,Jing Bai*,Yonghong Zhang department of Biomedical Engineering,tsinghua university,beijing {4.China department of Biomedical Engineering Tsinghua University Beijing 100084 China

In this paper,a normalized thoracic coordinate system(NTCS)is defined for rapidly mapping the 4. thoracic organ atlas into indi- vidual CT volume *** coordinate system is defined based on the thoracic *** coordinate values are normalized by the size of the individual thorax so that this coordinate system is universal to different *** compensating the respiratory motion of the organs,a 4. dynamic torso atlas is introduced.A method for mapping this dynamic atlas into the individual image using the NTCS is also *** this method,the dynamic atlas was mapped into the clinical thoracic CT images and rough positions of the organs were found *** NTCS-based 4. atlas mapping method may provide a novel way for estimating the thoracic organ positions in low-resolution molecular imaging modalities,as well as in modern 4. medical images.

关键词： Atlas mapping Registration Segmentation Molecular imaging

Stability of core-annular flow of power-law fluids in the presence of interfacial surfactant

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2010年第5期53卷 933-943页

作者： SUN XueWei,PENG Jie & ZHU KeQin department of Engineering Mechanics,tsinghua university,beijing {4.China 1. department of Engineering Mechanics Tsinghua University Beijing 100084 China

The shear-thinning influence on the core-annular flow stability of two immiscible power-law fluids is considered by making a linear stability *** flow is driven by an axial pressure gradient in a straight pipe with the interface between the two fluids occupied by an insoluble *** the basic flow for this core-annular arrangement,the analytical solution is obtained with respect to the power-law fluid *** linearized equations for the evolution of infinitesimal disturbances are derived and the stability problem is formulated as a generalized matrix eigenvalue problem,which is solved by using the software package Matlab based on the QZ *** shear-thinning property is found to have marked influence on the power-law fluid core-annular flow stability,which is reflected in various ***,the capillary instability is magnified by the shear-thinning property,which may lead to an essential difference between power-law and Newtonian fluid *** when the interface is close to the pipe wall,the power-law fluid flow may be unstable while the Newtonian fluid flow is ***,under disturbances to the interface a velocity discontinuity at the interface appears which is destabilizing to the *** magnitude of this velocity discontinuity is affected by the power-law index and the flow stability is influenced ***,the shear-thinning property may induce new stability modes which do not appear in the Newtonian fluid *** flow stability shows much dependence on the interface location,the role of which was neglected in most previous *** shear-thinning fluid flow is more unstable to long wave disturbances when the interface is close to the pipe wall,while the Newtonian fluid flow is more unstable when the interface is close to the pipe *** this trend is changed by the addition of interfacial surfactant,for which the power-law fluid flow is more stable no matter where the interface is loca

关键词： core-annular flow power-law fluid interfacial surfactant linear stability analysis

Entropy product measure for multipartite pure states

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2006年第5期49卷 606-615页

作者： CAO Wancang1,2, LIU Dan2, PAN Feng3 & LONG Guilu2,4.1. department of Physics, Chifeng College, Chifeng 024.01, China 2. Key Laboratory for Quantum Information and Measurements, department of Physics, tsinghua university, beijing {4. China 3. department of Physics, Liaoning Normal university, Dalian 116029, China 4. Key Laboratory for Atomic and Molecular Nano-sciences, tsinghua university, beijing {4. China Correspondence should be addressed to Long Guilu department of Physics Chifeng College Chifeng 024001 China Key Laboratory for Quantum Information Measurements Department of Physics Tsinghua University Beijing 100084 China department of Physics Liaoning Normal University Dalian 116029 China Key Laboratory for Atomic Molecular Nano-sciences Tsinghua University Beijing 100084 China

An entanglement measure for multipartite pure states is formulated using the product of the von Neumann entropy of the reduced density matrices of the constituents. Based on this new measure, all possible ways of the maximal entanglement of the triqubit pure states are studied in detail and all types of the maximal entanglement have been compared with the result of ‘the average entropy’. The new measure can be used to calculate the degree of entanglement, and an improvement is given in the area near the zero entropy.

关键词： multipartite pure state von Neumann entropy entanglement measure

A Remark on the Symplectic Blow-up in Dimension 4

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 1996年第4期12卷 379-384页

作者： Ma Renyi department of Applied Mathematics tsinghua university beijing, 100084.China department of Applied Mathematics Tsinghua University Beijing China

In this note, we prove that the symplectic blow-up or blow-down in the dimension 4.is rigid, i.e. the symplectic area of the divisor does not exceed the symplectic radius of the neighbourhood on which we do the blow-u... 详细信息

关键词： J-Holomorphic disc Contact manifold Symplectic blow-up