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Joint density of hitting time and point to an ellipse for Brownian motion

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Chinese Science Bulletin 1997年第24期42卷 2054-2058页

作者： YIN Chuancun ZHAO Xuelei department of Mathematics, Qufu normal University, Qufu 2.3165,{2. 2. Institute of Mathematics, Shantou University, Shantou 515063,{2. department of Mathematics Qufu Normal University Qufu China Institute of Mathematics Shantou University Shantou China

IT is well known that the distribution of hitting time, hitting point, last exiting time, and lastexiting point for Brownian motion to balls has been extensively studied. A similar investi-gation of rectangles or cubes has also been well done. However, analogous questions for Brow-nian motion to ellipsoid are rarely concerned. Bai and Cai obtained the distribution of

关键词： Brownian motion hitting time hitting point ellipse.

Free Volume Changes in γ-Irradiated Polyethylene and Polytetraflourethylene

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Journal of Materials Science & Technology 2000年第3期16卷 302-304页

作者： Xianyi ZHOU (Dept. of Modern physics, University of Science and Technology of china, Hefei 2.002., china) Linhua ZHAI (department of physics, Anhui normal University, Wuhu 2.1000, china) Jiangfeng DU and Rongdian HAN (department of Modern physics, Univers department of Modern physics University of Science and Technology of China Hefei 230027 China department of physics Anhui Normal University Wuhu 241000 China

Positron lifetime spectrum was measured and the change of the free volume was studied for commercial polyethylene (PE) and polytetrafluoroethylene (PTFE) during 7-irradiation processing up to 2.5 kGy. The free volume size increases but the crystallinity decreases as irradiation dose increases in PE. Both qualities (free volume size and crystallinity) in PTFE display an opposite behavior. The fractional free volume reduces monotonically with increasing irradiation dose in both PE and PTFE. The competition between the crosslinkmg and the splitting decomposition in polymers can be used to understand the free volume changes with irradiation dose.

关键词： PTFE Irradiated Polyethylene and Polytetraflourethylene

Engagement of PSGL-1 enhances β2.integrin-involved adhesion of neutrophils to recombinant ICAM-1

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Acta Pharmacologica Sinica 2006年第5期27卷 617-622页

作者： Xiao-guang WANG~(2.3) Yan-ping CHENG~4 Xue-qing BA~(2.5) ~2.nstitute of Genetics and Cytology Northeast normal University,Changchun 13002.,china:~3{2. of Biology,Changchun normal college,Changchun 130032.china ~4college of Life Science.Jilin normal University,Siping 136001,china Institute of Genetics and Cytology Northeast Normal University Changchun China department of Biology Changchun Normal College Changchun China college of Life Science Jilin Normal University Siping China

Aim:The interactions of selectins and their ligands initiate the process of leuko-cyte migrating into inflamed tissue.P-selectin glycoprotein ligand 1 （PSGL-1） isthe best characterized ligand of selectins,and has been demonstrated to mediatethe adhesion of leukocytes to all three selectins in ***-1 not only func-tions as an anchor molecule to capture the leukocytes to the activated endothelialcells by its interaction with selectins,but also transduces the signals to *** present work aimed to investigate the mechanism by whichPSGL-1-mediated signal activates neutrophils and enhances the adhesion to theendothelial ***:We detected the effects of the engagement of PSGL-1with monoclonal antibodies （mAb） or P-selectin on the adhesion of neutrophils tothe recombinant intercellular adhesion molecule-1 （ICAM-1）,and on the expres-sion of β***,the role of cytoskeleton in these process wasstudied by using inhibitor cytochalasin ***:The engagement of PSGL-Iincreased the expression of β2.integrin on the surface of neutrophils and en-hanced the adhesion of neutrophils to the recombinant *** againstCD18 impaired the adhesion of PSGL-1-engaged neutrophils to ***,the inhibitor cytochalasin B largely blocked the increase of CD 18 expression aswell as the adhesion of PSGL-1-engaged neutrophils to ***:The PSGL-1-transduced signals can enhance β2.integrin-involved adhesion ofneutrophils to the recombinant ICAM-1,and this process depends on the dynam-ics of cytoskeleton.

关键词： P-selectin ligand protein intercellular signaling peptides and proteins intercellular adhesion molecule-1 CD 18 antigens

Molecular modeling and spectroscopic studies on the binding of guaiacol to human immunoglobulin

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Science china Chemistry 2006年第6期49卷 550-559页

作者： HE Wenying1,2. YAO Xiaojun1, LIU Pengjun2. GAO Zhenxia2.& HU Zhide1 1. department of Chemistry, Lanzhou University, Lanzhou 730000, china 2. department of Chemistry, Hainan normal University, Hainan 571158, china department of Chemistry Lanzhou University Lanzhou China department of Chemistry Hainan Normal University Hainan China

The fluorogenic property of guaiacol was exploited for the first time to analyze the interaction with target protein as a probe by molecular modeling, fluorescence, circular dichroism (CD) and Fourier transform infrared (FT-IR) spectroscopy. Molecular docking was performed to reveal the possible binding mode or mechanism and suggested that guaiacol can strongly bind to human immu- noglobulin (HIgG). It is considered that guaiacol binds to HIgG mainly by a hydrophobic interaction and there are two hydrogen bond interactions between the drug and the residues LEU 80 and ASP 65, which is in good agreement with the results from the experimental thermodynamic parameters (the enthalpy change △H0 and the entropy change △S0 were calculated to be 65.55 kJ·mol-1 and 132.95 J·mol-1·K-1 according to the Vant’ Hoff equation). Data obtained by the fluorescence spectroscopy indicated that binding of guaiacol with HIgG leads to dramatic enhancement in the fluorescence emission intensity along with significant occurrence of efficient Frster resonance energy transfer (FRET) from the residue of HIgG to the protein bound guaiacol. From the low value of fluorescence anisotropy (r = 0.06), it is argued that the probe molecule is located in the motionally unrestricted environment of the protein. The alterations of protein’s secondary structure in the presence of guaiacol in aqueous solution were quantitatively calculated by the evidences from FT-IR and CD spectroscopes.

关键词： guaiacol, human immunoglobulin, molecular modeling, fluorescence enhancement, Fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD).

The best quadrature based on given Hermite information for the Sobolev class KW^r[a,b]

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Science china Mathematics 2006年第8期49卷 1146-1152页

作者： WANG Xinghua & YANG Shijun department of Mathematics, Zhejiang University, Hangzhou 31002., china department of Mathematics, Hangzhou normal college, Hangzhou 310036, china department of Mathematics Zhejiang University Hangzhou China department of Mathematics Hangzhou Normal College Hangzhou China

As usual, denote by KWr[a,b] the Sobolev class consisting of every function whose (r-1)th derivative is absolutely continuous on the interval [a,b] and rth derivative is bounded by K a.e. In [a,b]. For a function f ∈ KWr[a,b], its values and derivatives up to r-1 order at a set of nodes x are known. These values are said to be the given Hermite *** work reports the results on the best quadrature based on the given Hermite information for the class KWr[a,b]. Existence and concrete construction issue of the best quadrature are settled down by a perfect spline interpolation. It turns out that the best quadrature depends on a system of algebraic equations satisfied by a set of free nodes of the interpolation perfect spline. From our another new result, it is shown that the system can be converted in a closed form to two single-variable polynomial equations, each being of degree approximately r/2. As a by-product,the best interpolation formula for the class KWr[a,b] is also obtained.

关键词： Sobolev class, Hermite information, perfect spline, optimal recovery, best quadrature.

Taxonomic circumscription of Sinojackia xylocarpa (Styracaceae)

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Journal of Systematics and Evolution 2011年第2期49卷 163-164页

作者： 1 Li-Qun LUO 2.Chi LUO 1 (department of Chemistry and Life Science, Leshan normal University, Leshan 614004,{2.) 2.(department of Mathematics, Leshan normal University, Leshan 614004,{2.) (department of Chemistry and Life Science Leshan Normal University Leshan 614004 China) (department of Mathematics Leshan Normal University Leshan 614004 China)

Sinojackia xylocarpa Hu in Journ. Arn. Arb. 9: 130. 192.. Type: china. Jiangsu: Nanjing, Y. L. Keng 1376 (PE!). Sinojackia rehderiana Hu in Journ. Arn. Arb. 11: 2.7. 1930, syn. nov. Type: china. Jiangxi: Nanchang, H. ... 详细信息

关键词： PE Styracaceae Taxonomic circumscription of Sinojackia xylocarpa

Short cycle structures for graphs on surfaces and an open problem of Mohar and Thomassen

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Science china Mathematics 2006年第2期49卷 212-224页

作者： REN Han & DENG Mo department of Mathematics, East china {2. University, Shanghai 2.0062. china college of Mathematics & Information Science, Northwest {2. University, Lanzhou 730070, china department of Mathematics East China Normal University Shanghai China college of Mathematics & Information Science Northwest Normal University Lanzhou China

In this paper we investigate cycle base structures of a (weighted) graph and show that much information of short cycles is contained in an MCB (i.e., minimum cycle base). After setting up a Hall type theorem for base-transformation, we give a sufficient and necessary condition for a cycle base to be an MCB. Furthermore, we show that the structure of MCB in a (weighted)graph is unique. The property is also true for those having a longest length (although much work has been down in evaluating MCB, little is known for those having a longest length). We use those methods to find out some unknown properties for short cycles sharing particular properties in (unweighted) graphs. As applications, we determine the structures of short cycles in an embedded graph and show that there exist polynomially bounded algorithms in finding a shortest contractible cycle and a shortest two-sided cycle provided such cycles exist. Those answer an open problem of B. Mohar and C. Thomassen.

关键词： cycle base facial cycle graph embedding.

Travelling wave solutions of a generalized Camassa-Holm-Degasperis-Procesi equation

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Science china Mathematics 2011年第3期54卷 555-572页

作者： DENG ShengFu1, GUO BoLing2.& WANG TingChun2.3 1department of Mathematics, Zhanjiang normal University, Zhanjiang 52.048,{2. 2.nstitute of Applied physics and Computational Mathematics, Beijing 100088,{2. 3 college of Math and physics, Nanjing University of Information Science and Technology, Nanjing 2.0044,{2. department of Mathematics Zhanjiang Normal University Zhanjiang China Institute of Applied physics and Computational Mathematics Beijing China college of Math and physics Nanjing University of Information Science and Technology Nanjing China

The travelling wave solutions of a generalized Camassa-Holm-Degasperis-Procesi equation ut-uxxt + (1 + b)umux = buxuxx + uuxxx are considered where b > 1 and m are positive integers. The qualitative analysis methods of planar autonomous systems yield its phase portraits. Its soliton wave solutions, kink or antikink wave solutions, peakon wave solutions, compacton wave solutions, periodic wave solutions and periodic cusp wave solutions are obtained. Some numerical simulations of these solutions are also given.

关键词： homoclinic orbits heteroclinic orbits peakon wave solutions compacton wave solutions periodic cusp wave solutions

Kinetics and mechanism of the reaction between thiourea and iodate in unbuffered medium

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Science china Chemistry 2004年第6期47卷 480-487页

作者： WANG Shun1,2. LIN Juanjuan1, CHEN Fan1, HU Maolin1, HU Xingen1, HAN Yiping1 & GAO Qingyu2.1.department of Chemistry and Material Science, Wenzhou normal {2., Wenzhou 32.02., china 2. {2. of Chemical Engineering, china University of Mining and Technology, Xuzhou 2.1008, china department of Chemistry and Material Science Wenzhou Normal College Wenzhou China college of Chemical Engineering China University of Mining and Technology Xuzhou China

The reaction between iodate and thiourea has been studied in an unbuffered acidic medium. In excess iodate the reaction shows not only oligooscillations in pH, Pt potential and the concentration of iodide ion, [I?], but also an initial induction period which has the linear relation with initial pH. At the end of the induction period, [I?] decreases sharply and a yellow coloration (due to iodine) appears transiently. While in excess thiourea iodine is produced and finally con- sumed, leaving milky deposits (due to sulfur) at the end of the reaction. The induction period from the start of the reaction to the maximum of [I2. is also directly proportional to initial pH. A 14-step mechanism, including a H+-mediated preequalibrium, Dusman reaction, iodine-sulfur reactions and sulfur-sulfur reactions, is proposed. Computer simulations using this mechanism give good agreement with experiments.

关键词： oligooscillations, pH dynamics, thiourea, iodate, complex reaction mechanism, dynamic simulation.