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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 Science and Technology of China, Hefei 230026, China 2. Department of Physics, Yantai Teachers University, Yantai 264025, 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).

Synthesis of different-sized gold nanostars for Raman bioimaging and photothermal therapy in cancer nanotheranostics

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中国科学：化学英文版 2017年第9期60卷 1219-1229页

作者： Jie Gao Maria Sanchez-Purra Hao Huang ShunhaoWang Yunan Chen Xuefeng Yu Qian Luo Kimberly Hamad-Schifferli Sijin Liu State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences.Beijing 100049 China Department of Engineerfng University of Massachusetts BostonBostonMA 02125United States Institute of Biomedicine and Biotechnology Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMA 02139United States

Gold nanoparticles(AuNPs) have been attractive for nanomedicine because of their pronounced optical ***,we customerized the methods to synthesize two types of gold nanostars,Au nanostars-1 and Au nanostars-2,which have different spire lengths and optical properties,and also spherical *** to nanospheres,gold nanostars were less toxic to a variety of cells,including *** nanostars-1 and Au nanostars-2 also manifested a similar pattern of tissue distribution upon in vivo administration in mice to that of nanospheres,and but reveled less liver retention than *** to their strong absorption in the near-infrared(NIR),Au nanostars-2 induced a strong hyperthermia effect in vitro upon excitation at 808 nm,and elicited a robust photothermal therapy(PTT) efficacy in ablating tumors in a mouse model of orthotopic breast cancer using 4T1 breast cancer ***,Au nanostars-1 showed a great capability to enhance the Raman signal through surface-enhanced Raman spectroscopy(SERS) in 4T1 *** combined results opened a new avenue to develop Au nanostars for cancer imaging and therapy.

关键词： gold nanoparticle, nanostar, surface plasmon resonance, tissue distribution, toxicity profile

Negative Index Materials and Their Applications:Recent Mathematics Progress(Dedicated to Ham Brezis for his 70th birthday with esteem)

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Chinese Annals of Mathematics,Series B 2017年第2期38卷 601-628页

作者： Hoai-Minh NGUYEN EPFL SB MATHAA CAMA Station 8CH-1015 LausanneSwitzerland

Negative index materials are artificial structures whose refractive index has negative value over some frequency range. These materials were first investigated theoretically by Veselago in 1946 and were confirmed experimentally by Shelby, Smith, and Schultz in2001. Mathematically, the study of negative index materials faces two difficulties. Firstly,the equations describing the phenomenon have sign changing coefficients, hence the ellipticity and the compactness are lost in general. Secondly, the localized resonance, i.e.,the field explodes in some regions and remains bounded in some others as the loss goes to 0, might appear. In this survey, the author discusses recent mathematics progress in understanding properties of negative index materials and their applications. The topics are reflecting complementary media, superlensing and cloaking by using complementary media, cloaking a source via anomalous localized resonance, the limiting absorption principle and the well-posedness of the Helmholtz equation with sign changing coefficients.

关键词： Negative index materials, Localized resonance, Cloaking, Superlensing

Mechanism of proton anisotropic velocity distribution in the solar wind

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Science China(Physics,Mechanics & Astronomy) 2003年第1期46卷 78-83页

作者：敖先志沈迹涂传诒 Department of Geophysics Peking UniversityBeijing 100871China

Although it has been long that spacecraft observed the anisotropy of velocity protons in the solar wind, there is still not a reasonable explanation. In this paper we try to give an explanation from the diffusion plateau of protoncyclotron resonance predicted by the quasi-linear theory for the resonance between the protons and the parallel propagating waves. We consider the effect of dispersion relation on diffusion plateau and notice that the diffusion plateau we have got by using cold plasma dispersion relation accords with the density contours in the velocity phase space detected at 0.3 AU in fast solar wind. For explaining proton distributions obtained in the fast solar wind from 0.7 AU to 1 AU hot plasma dispersion relation should be considered. We also give a theoretical relation of proton thermal anisotropy A and plasma parameter β.

关键词： solar wind, cyclotron resonance, quasi-linear theory, diffusion plateau.

Mechanical model of vulnerable atherosclerotic plaque rupture

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Science China(Physics,Mechanics & Astronomy) 2004年第4期47卷 452-462页

作者： SU Haijun1, ZHANG Mei2 & ZHANG Yun2 1. School of Mathematics and System Science, Shandong University, Jinan 250100, China 2. Qilu Hospital, Shandong University, Jinan 250012, China School of Mathematics and System Science Shandong University Jinan China Qilu Hospital Shandong University Jinan China

Rupture of atherosclerotic plaque is the main trigger of acute cardiovascular events, but the mechanism of plaque rupture is still unknown. We have constructed a model describing the motion of the fibrous cap of the plaque using the theory of elastic mechanics and studied the stability of the plaque theoretically. It has shown that plaque rupture is the result of a dynamic interplay between factors intrinsic to the plaque itself and extrinsic factors. We have proposed a new mechanism of plaque rupture, given a new explanation about the nonlinear dynamic progress of atherosclerosis and suggested a method to identify the vulnerable plaques to manage atherosclerosis.

关键词： fibrous cap, parametric resonance, stability, mechanism, identification.

Calculations of the Spin-Lattice Coupling Coefficients Fij and Zij for MgO:Co2+Crystal

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Communications in Theoretical Physics 2001年第10期36卷 487-490页

作者： ZHENG Wen-Chen WU Shao-Yi Department of Materials Science Sichuan University Chengdu 610064 China International Centre for Materials Physics The Chinese Academy of Sciences Shenyang 110015 China Department of Materials Science Sichuan University Chengdu 610064 China International Centre for Materials Physics The Chinese Academy of Sciences Shenyang 110015 China

According to a uniform and simple method of calculating spin-lattice coupling coefficients and the pert1rbation formulas of gi factors and hyperfine structure constants Ai based on the cluster approach for 3d7 ions in cubic,tetragonal and trigonal octahedral crystal fields, the spin-lattice coupling coefficients Fij (F11, Fl2, F44), Zij (Z11, Z12,Z44) and also g factor and hyperfine constant A for MgO:Co2+ are calculated by using the parameters obtained from the optical spectra without adjustable parameters. The calculated results show good agreement with the observed *** difiiculty in explaining the coeficients Fij and Zij is therefore removed.

关键词： spin-lattice coupling coefficients, electronic paramagnetic resonance, crystal- and ligand-field theory, Co2+, MgO crystal

风力机组整机多体动力学建模与动态特性研究（英文）

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机床与液压 2015年第24期43卷 7-14页

作者：海几哲孙文磊周玉俊新疆大学机械工程学院乌鲁木齐830047

选取某MW级风力发电机组为研究对象,设计了机组运动拓扑结构图,构建了风机整机的刚柔耦合多体动力学分析模型,并与气动力计算软件Aero Dyn和控制求解器通过接口力元实现联合仿真。模态分析计算得到了整机前6阶固有频率和模态振型,分析...

选取某MW级风力发电机组为研究对象,设计了机组运动拓扑结构图,构建了风机整机的刚柔耦合多体动力学分析模型,并与气动力计算软件Aero Dyn和控制求解器通过接口力元实现联合仿真。模态分析计算得到了整机前6阶固有频率和模态振型,分析可知机组与关键转速区间激振频率不发生共振。动态仿真计算得到了3种不同工况下风机塔架迎风方向的位移、加速度动响应以及叶片三坐标方向的叶尖挠度,分析发现阵风期间塔架位移突然增大且瞬时波动剧烈;叶片的x方向叶尖挠度值最大,可能使叶片和塔架发生碰撞。

关键词： Wind turbine, Multi-body dynamics, Coupled rigid and flexible multi-body, resonance, Dynamicresponse