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Structure and kinematic analysis of a novel 2.DOF translational parallel robot

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Progress in Natural science:Materials International 2007年第10期17卷 1213-1219页

作者： Chen Tao1, Wu Chao2.and Liu Xinjun2.1. School of Application science and Technology, Harbin university of science and Technology, Harbin 150080, china 2. department of Precision Instruments, Tsinghua university, Beijing 100084, china) School of Application science and Technology Harbin University of Science and Technology Harbin 150080 China department of Precision Instruments Tsinghua University Beijing 100084 China

This paper addresses the analysis of a novel parallel robot with 2.translational degrees of freedom (DOFs). The robot can position a rigid body in a plane with constant orientation. The kinematic structure of the robot is first described in detail. Some kinematic problems, such as the inverse and forward kinematics, velocity, and singularity are then analyzed. The working and assembly modes are discussed. Since it is the most important index to design a robot, the workspace of the robot is studied systematically in this paper. Based on the analysis of reachable workspace and singularity, a kind of workspace concept characterizing the region that the end-effector of the robot can reach in practice is defined. The results of this paper will be very useful for the design and application of the robot.

关键词： parallel robot degree of freedom kinematics workspace.

The localization of 1-cohomology of transitive Lie algebroids

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science china Mathematics 2006年第2期49卷 277-288页

作者： CHEN Zhuo & LIU Zhangju department of Mathematics, capital Normal {2., Beijing 100037, china School of Mathematical science, Peking {2., Beijing 100871, china department of Mathematics Capital Normal University Beijing China School of Mathematical science Peking University Beijing China

For a transitive Lie algebroid A on a connected manifold M and its representation on a vector bundle F, we define a morphism of cohomology groups rk: Hk(A, F) → Hk(Lx, Fx),called the localization map, where Lx is the adjoint algebra at x ∈ M. The main result in this paper is that if M is simply connected, or H0(Lx, Fx) is trivial, then r1 iS injective. This means that the Lie algebroid 1-cohomology is totally determined by the 1-cohomology of its adjoint Lie algebra in the above two cases.

关键词： transitive Lie algebroid representation cohomology localization.

Sonic hedgehog protein promotes bone marrow-derived endothelial pro-genitor cell proliferation,migration and VEGF production via PI 3-kinase/Akt signaling pathways

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Acta Pharmacologica Sinica 2006年第6期27卷 685-693页

作者： Jin-rong FU~2.Wen-li LIU~(2.4)Jian-feng ZHOU~2.Han-ying SUN~2.Hui-zhen XU~2.Li LUO~2.Heng ZHANG~2.Yu-feng ZHOU~3 2.department of Hematology.Tongji hospital,Tongji {2. College,Huazhong university of science and Technology,Wuhan 430030,china:3 department of Pediatrics,Tongji hospital,Tongji {2. College,Huazhong university of science and Technology,Wuhan 430030,china department of Hematology Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China department of Pediatrics Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Wuhan China

Aim:To investigate the effects of Sonic hedgehog(shh)protein on bone marrow-derived endothelial progenitor cells(BM-EPC)proliferation,migration and vascu-lar endothelial growth factor(VEGF)production,and the potential signaling path-ways involved in these ***:Bone marrow-derived Flk-1~+ cells wereenriched using the MACS system from adult Kunming mice and then BM-EPCwas cultured in gelatin-coated culture *** effects of shh N-terminal pep-tide on BM-EPC proliferation were evaluated using the MTT colorimetric *** migration was assayed using a modified Boyden chamber *** of VEGF was determined by ELISA and immunofluorescence *** potential involvement of PKC and PI3K signaling pathways was exploredusing selective inhibitor or Western ***:The proliferation,migrationand VEGF production in BM-EPC could be promoted by endogenous shh N-terminal peptide at concentrations of 0.1μg/mL to 10 μg/mL,and could be inhib-ited by anti-shh ***-mediated proliferation and migration in BM-EPCcould be partly attenuated by ***-PI3-kinase expression in newlyseparated BM-EPC was low,and it increased significantly when exogenous shhN-terminal peptide was added,but could be attenuated by anti-human/mouse shhN-terminal peptide ***,the inhibitor of the PI3-kinase,but notthe inhibitor of the PKC,significantly inhibited the shh-mediated proliferation,migration and VEGF ***:Shh protein can stimulate bonemarrow-derived BM-EPC proliferation,migration and VEGF production,whichmay promote neovascularization to ischemic *** results also suggeststhat the PI3-kinase/Akt signaling pathways are involved in the angiogenic effectsof shh.

关键词： mouse Sonic hedgehog protein endothelial cells stem cells protein kinase C 1-phosphatidylinositol 3-kinase vascular endothelial growth factor A cell proliferation emigration immigration

Internal noise stochastic resonance in CO oxidation on nm-sized palladium particles

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science china Chemistry 2005年第5期48卷 395-401页

作者： GONG Yubing1,2. HOU Zhonghuai1 & XIN Houwen1 1. department of Chemical Physics, university of {2. and Technology of china, Hefei 2.002., china 2. department of Physics, Yantai Teachers university, Yantai 2.402., china department of Chemical Physics University of Science and Technology of China Hefei China department of Physics Yantai Teachers University Yantai China

Based on a stochastic mesoscopic model, the influence of internal noise on the oscillatory kinetics of the catalytic oxidation of CO on nm-sized palladium particles is studied, using the chemical Langevin equations, Poisson approximation algorithm, and exact stochastic simulation algorithm. The reaction rate oscillations are of stochastic nature due to considerable internal noise in such mesoscopic systems. It is found that the performance of the stochastic oscillations undergoes a maximum with the variation of internal noise level for a given CO partial pressure, which demonstrates the occurrence of internal noise stochastic resonance. This phe-nomenon implies that optimal internal noise would favor the reaction rate oscillation of CO oxi-dation on nm particles. Such a phenomenon is robust to the change of external parameters, such as CO pressures.

关键词： nanometer-sized palladium particles, surface catalytic CO oxidation, internal noise, stochastic resonance, chemical Langevin equation.

Stochastic resonance in surface catalytic oxidation of carbon monoxide induced by colored noise

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science china Chemistry 2004年第2期47卷 106-112页

The dynamical behavior of surface catalytic oxidation reaction of Pt(110)/CO+O2.modulated by colored noise, under the condition of specific temperature, has been investigated when the partial pressure of CO gas is near the supercritical Hopf bifurcation point. By computer simulation the oscillation and stochastic resonance induced by colored noise are observed. The influences of the intensity and correlation time of colored noise on stochastic resonance are discussed. The range of sensitivity of the system to the environmental fluctuation is analyzed.

关键词： colored noise, stochastic resonance, surface catalytic reaction of Pt(110)/CO+O2. supercritical Hopf bifurcation, signal-to-noise ratio (SNR).

Anisotropic effect on the vibronic reduction factors

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Chinese science Bulletin 2006年第21期51卷 2553-2558页

作者： QIU Qing-chun1,2.& QIAO Fen1,2.1. department of Physics and IT, medical College, Shantou {2.,Shantou 515041, china 2. department of Physics, Shantou {2., Shantou 515063, china department of Physics and IT Medical College Shantou University Shantou China department of Physics Shantou University Shantou China

The reduction factors p and q defined by Ham in the Ee JT system and their relation 2.-p=1 have been well accepted and the concept of reduction factors is widely used in the studies of vibronic coupling. However, when the system is under the anisotropic conditions, the reduction factors and their relation will change accordingly. The first-order reduction factors p and q of Ee system were further studied using the method of unitary transformation here. The relation between p and q proposed by Ham was investigated under both conditions of the linear coupling and the anisotropic effects. The result demonstrated that the relation of 2.-p=1 was only correct for the linear vibronic coupling, but not correct when the anisotropic effect was considered. This result suggested that the anisotropic effect influence considerably the reduction factors, and hence the physical properties of materials. Our method could be also applied to other JT systems, especially the highly symmetric JT systems involving C60 molecules.

关键词：电子振动耦合声子交迭 Jahn-Teller效应各向异性

An equality on Hochschild homology groups

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Chinese science Bulletin 1997年第8期42卷 624-627页

作者： ZHANG Pu and LIU Shaoxue1. department of Mathematics, university of {2. and Technology of china, Hefei 2.002., china 2. department of Mathematics, Beijing Normal university, Beijing 100875, china department of Mathematics University of Science and Technology of China Hefei China department of Mathematics Beijing Normal University Beijing China

LET A be finite-dimensional algebra over field k,and Ae the enveloping algebra of A,i.e.Ae=A kAop,where Aop is the opposite algebra of *** A-bimodule has a natural left Ae-module structure as follows:

关键词： finite-dimensional algebra Hochschild homology groups dimensions.

Overexpression of cyclin Y in non-small cell lung cancer is associated with cancer cell proliferation

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science china(Life sciences) 2010年第4期53卷 511-516页

作者： YUE WenTao1, ZHAO XiaoTing1, ZHANG LiNa1, LIU ZhiDong2. MA Li1, JIA WenYun1, QIAN Zhe1, ZHANG ChunYan1, WANG Yue1, YANG XueHui1 & XU ShaoFa2.1 department of Cellular Biology, Beijing Chest hospital, {2. medical university, Beijing, 101149, china 2.department of Thoracic Surgery, Beijing Chest hospital, {2. medical university, Beijing, 101149, china department of Cellular Biology Beijing Chest Hospital Capital Medical University Beijing China department of Thoracic Surgery Beijing Chest Hospital Capital Medical University Beijing China

Cyclin Y (CCNY) is a key cell cycle regulator that acts as a growth factor sensor to integrate extracellular signals with the cell cycle machinery. The expression status of CCNY in lung cancer and its clinical significance remain unknown. The data indicates that CCNY may be deregulated in non-small cell lung cancer, where it may act to promote cell proliferation. These studies suggest that CCNY may be a candidate biomarker of NSCLC and a possible therapeutic target for lung cancer treatment.

关键词： CCNY NSCLC lentivirus RNAi H12.9

Topological chirality and achirality of the closed circular DNAs

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Chinese science Bulletin 1997年第20期42卷 1705-1708页

作者： QIU Wenyuan and XIN Houwen1. department of Chemical Physics, university of {2. and Technology of china, Hefei 2.002., china 2. department of Chemistry, Lanzhou university, Lanzhou 730000, china department of Chemical Physics University of Science and Technology of China Hefei China department of Chemistry Lanzhou University I anzhou China

THE study of the relations between the topological structure and its function is one of the focus-es in modern chemistry and life science. In this note we set up a topological model to de-scribe the ccDNAs on the basis of Seifert construction in knot theory. Our model for theccDNAs helps to determine whether a structure is topologically chiral or achiral. This is one ofthe fundamental biological problems.

关键词： DNA topology knot theory topologiesl chirality topological achirality.