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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

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.

Formation of bulk ferromagnetic nanostructured Fe_(40)Ni_(40)P_(14)B_6 alloys by metastable liquid spinodal decomposition

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Science china(Technological Sciences) 2009年第7期52卷 1919-1922页

作者： lI Qiang1,2 1 School of physics Science and Technology, Xinjiang university, Urumqi 830046, china 2 department of physics, The Chinese university of hongKong, Shatin N.T., hongKong, china School of physics Science and Technology Xinjiang University Urumqi 830046 China department of physics The Chinese University of HongKong Shatin N.T. HongKong China

Nanostructured Fe40Ni40P14B6 alloy ingots of 3―5 mm in diameter could be synthesized by a metastable liquid state spinodal decomposition method. For undercooling T> 260 K, the microstructure of the undercooled specimen had exhibited liquid state spinodal decomposition in the undercooled liquid state. The microstructure could be described as two intertwining networks with small grains dispersed in them. For undercooling T>290 K, the overall microstructure of the specimen changed into a granular morphology. The average grain sizes of the small and large grains are 30 nm and 80 nm, respectively. These prepared samples are soft magnets with saturation magnetization Bs 0.744 T.

关键词： nanomaterials magnetic materials solidification bulk nanostructured alloy Fe40Ni40P14B6 metastable liquid spinodal decomposition

Density-functional formula for strongly correlated systems

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Progress in Natural Science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1*, HAN Rushan2 and CHEN Nanxian1(1. department of physics, Tsinghua university, Beijing 100084, china 2. department of physics, Peking university, Beijing 100871, china) department of physics Tsinghua University Beijing 100084 China department of physics Peking University Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.

X-ray spectra induced by ^(129)Xe^(q+) impacting the metal surface

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Science china(physics,Mechanics & Astronomy) 2008年第1期51卷 82-89页

作者： ZHANG XiaoAn 1,2 ,XIAO GuoQing 1 ,YANG ZhiHu 1 ,CHEN XiMeng 3 ,ZHAO YongTao 1 , lI Fuli 4 ,WANG li 1,2 ,CUI Ying 3 ,ZHANG hongQiang 3 &ZHAN Wenlong 1 1Institute of Modern physics,Chinese Academy of Sciences,lanzhou 730000,china 2department of physics,Xianyang Normal university,Xianyang 712000,china 3department of Modern physics,lanzhou university,lanzhou 730000,china 4department of Applied physics,Xi’an Jiaotong university,Xi’an 710049,china 1. Institute of Modern physics Chinese Academy of Sciences Lanzhou 730000 China 2. department of physics Xianyang Normal University Xianyang 712000 China 3. department of Modern physics Lanzhou University Lanzhou 730000 China 4. department of Applied physics Xi’an Jiaotong University Xi’an 710049 China

Using the slow highly charged ions 129 Xe q+ (q=25,26,27;initial kinetic T0≤4.65 keV/a.u.)to impact Au surface,the Au atomic Mαcharacteristic X-ray spectrum is *** result shows that as long as the charge state of projectile is high enough,the heavy atomic characteristic X-ray can be effectively excited even though the incident beam is very weak(nA magnitude),and the X-ray yield per ion is in the order of 10-8and increases with the kinetic energy and potential energy of *** measuring the Au Mα-X-ray spectra,Au atomic N-level lifetime is estimated at about 1.33.10-18s based on Heisenberg uncertainty relation.

关键词： slow highly charged ions characteristic X-ray level lifetime

A New Multisoliton Solution to (2+1)-Dimensional KdV Equation

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Communications in Theoretical physics 2004年第5期41卷 669-670页

作者： PENG Yan-Ze~(1,2) 1 department of Mathematics,Huazhong university of Science and Technology,Wuhan 430074,china2 department of Mathematics and physics,Henan university of Science and Technology,luoyang 471003,china department of Mathematics and physics Henan University of Science and Technology Luoyang 471003 China

A new multisoliton solution to the(2+1)-dimensional KdV equation is obtained by means of the truncatedPainleve expansion method and a direct ansatz *** new exact solution is periodic in the propagating directionx and exponentially decaying in y and thus it is called periodic solitons.A typical spatial structure of it is illustrated bythe figures.

关键词： (2+1)-dimensional KdV equation periodic solitons truncated Painleve expansion method

Adsorption behavior and mechanism of D113 resin for lanthanum

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Rare Metals 2007年第6期26卷 601-606页

作者： SHU Zengnian XIONG Chunhua SHEN Qiuxian YAO Caiping GU Zhenyu department of Chemistry Lishui University Lishui 323000 China College of Food Science Biotechnology and Environmental Engineering Zhejiang Gongshang University Hangzhou 310035 China

The sorption properties of macroporous weak acid resin （D113） for la^3＋ ion were studied by chemical analysis and IR spectra. Experimental results indicate that the D113 resin has a good adsorption ability for la^3＋ at pH = 6.0 in the HAc-NaAc medium. The statically saturated adsorption capacity is 273.3 mg/g. Separation coefficients of βla^3＋/Ce^3＋, βla^3＋/Gd^3＋, βla^3＋/Er^3＋, and βla^3＋/Y^3＋ are 2.29, 3.64, 4.27, and 0.627, respectively. The apparent activation energy of adsorption, Ea is 18.4 kJ/mol, the thermodynamics parameters AH, AS, and AG of sorption are 4.53 kJ/mol, 61.8 J/（mol·K）, -13.9 kJ/mol, respectively. The adsorption behavior of D113 for la^3＋ obeys the Freundlich isotherm. la^3＋adsorbed on resin can be eluted by 2.0 mol/l HCl quantitatively.

关键词： adsorption macroporous weak acid resin lanthanum mechanism kinetics

An investigation of hadronization mechanism at a Z^0 factory

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Science china(physics,Mechanics & Astronomy) 2010年第11期53卷 1998-2004页

作者： JIN Yi 1,SI ZongGuo 2,XIE QuBing 2 & YAO Tao 2 1 department of physics,university of Jinan,Jinan 250022,china 2 School of physics,Shandong university,Jinan 250100,china 1. department of physics University of Jinan Jinan 250022 China2. School of Physics Shandong University Jinan 250100 China

We briefly review the hadronization pictures adopted in the lUND String Fragmentation Model (lSFM),Webber Cluster Fragmentation Model (WCFM) and Quark Combination Model (QCM),*** of hadron multiplicity,baryon to meson ratios and baryon-antibaryon flavor correlations,especially those related to heavy hadrons at a Z 0 factory obtained by lSFM and QCM,are reported.

关键词： Z0 factory hadronization model baryon to meson ratio B correlation

Pairwise entanglement and local polarization of Heisenberg model

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Science china(physics,Mechanics & Astronomy) 2008年第10期51卷 1515-1522页

作者： XI XiaoQiang1,2, ZHANG Tao3, YUE Ruihong3,4 & lIU WuMing2 1 department of Applied Mathematics and physics, Xi’an Institute of Post and Telecommunications, Xi’an 710061, china 2 Beijing National laboratory for Condensed Matter physics, Institute of physics, Chinese Academy of Sciences, Beijing 100080, china 3 Institute of Modern physics, Northwest university, Xi’an 710069, china 4 department of physics, Ningbo university, Ningbo 315211, china department of Applied Mathematics and physics Xi’an Institute of Post and Telecommunications Xi’an 710061 China Beijing National laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China Institute of Modern physics Northwest University Xi’an 710069 China department of physics Ningbo University Ningbo 315211 China

The characteristics of pairwise entanglement and local polarization (lP) are dis-cussed by studying the ground state (states) of the Heisenberg XX model. The re-sults show that: the ground state (states) is (are) composed of the micro states with the minimal polarization (0 for even qubit and 1/2 for odd qubit); lP and the prob-ability of the micro state have an intimate relation, i.e. the stronger the lP, the smaller the probability, and the same lP corresponds to the same probability; the pairwise entanglement of the ground state is the biggest in all eigenvectors. It is found that the pairwise entanglement is decreased by the state degeneracy and the system size. The concurrence approaches a fixed value of about 0.3.12 (for odd-qubit chain) or 0.3491 (for even-qubit chain) if the qubit number is large enough.

关键词： Heisenberg XX model local polarization pairwise entanglement

Microstructure evolution of single crystal copper wires in cold drawing

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Science china(Technological Sciences) 2007年第6期50卷 736-748页

作者： CHEN Jian1,2, YAN Wen1,2, WANG XueYan2 & FAN XinHui2 1 department of Applied physics, Northwestern Polytechnical university, Xi’an 710072, china 2 School of Material Science and Chemical Engineering, Xi’an Technological university, Xi’an 710032, china 1. department of Applied physics Northwestern Polytechnical University Xi’an 710072 China 2. School of Material Science and Chemical Engineering Xi’an Technological University Xi’an 710032 China

The deformation microstructure evolution of single crystal copper wires produced by OCC method has been studied with the help of TEM, EBSD; OM. The results show that there are a small number of dendrites; twins in the undeformed single crystal copper wires. However, it is difficult to observe these dendrites in deformed single crystal copper wires. The structure evolution of deformed single crystal copper wires during drawing process can be divided into three stages. When the true strain is lower than 0.94, macroscopic subdivision of grains is not evident,; the microscopic evolution of deformed structure is that the cells are formed; elongated in drawn direction. When the true strain is between 0.94; 1.96, macroscopic subdivision of grains takes place,; the number of microbands located on {111}; cell blocks is much more than that with the true strain lower than 0.94. When the true strain is larger than 1.96, the macroscopic subdivision of grains becomes more evident than that with the true strain between 0.94; 1.96,; S-bands structure; lamellar boundaries will be formed. From EBSD analysis, it is found that part of 100 texture resulting from solidifying is transformed into 111; 112 due to shear deformation, but 100 texture component is still kept in majority. When the true strain is 0.94, the misorientation angle of dislocation boundaries resulting from deformation is lower than 14°. However, when the true strain arrives at 1.96, the misorientation angle of some boundaries will be greater than 50°,; the peak of misorientation angle distribution produced by texture evolution is located in the range between 25°; 30°.

关键词： single crystal copper wires, deformation structure, electron backscattering diffraction, transmission electron microscopy