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Journal of university of science and technology beijing 2004年第3期11卷 235-239页

作者： Yan Huang Hong Qiu Liqing Pan Yue Tian Fengping Wang ping wu department of physics, applied science school, university of science and technology beijing, beijing 100083, china Dept. of Phys. Appl. Sci. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

110 nm-thick Au layers were sputter-deposited on unheated glasses coatedabout a 10 nm-thick and a 50 nm-thick Cr layer respectively. The Au/Cr bilayer films were annealedin a vacuum of 1 mPa at 300℃ for 2, 5 and 30 min, respectively. Auger electron spectroscopy, X-raydiffraction and Field emission scanning electron microscopy were used to analyze the composition andstructure of the Au layers. The resistivity of the bilayer films was measured by using four-pointprobe technique. The adhesion of the bilayer films to the substrate was tested using tape tests. Theamount of Cr atoms diffusing into the Au layer increases with increasing the annealing time,resulting in a decrease in lattice constant and an increase in resistivity of the Au layer. Thecontent of Cr inside the Au layer grown on the thinner Cr layer is less than that grown on thethicker Cr layer. For the Au/Cr bilayer films, the lower resistivity and the good adhesion to theglass substrate can be obtained at a shorter annealing time for a thinner Cr layer.

关键词： Au/Cr bilayer film Cr layer thickness annealing characteristic

An atomistic simulation of site preference and vibrational properties of UMxAl12-x (M = Fe, Co, Ni, Cr and Mn) and UMxAl12-xHx

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Progress in Natural science:Materials International 2009年第8期19卷 983-989页

作者： Huijun Tian a,b, ping Qian a, Jiang Shen a, Nanxian Chen a,c a Institute of applied physics, beijing university of science and technology, beijing 100083, china b school of physics, beijing university of Chemical technology, beijing 100029, china c department of physics, Tsinghua university, beijing 100084, china [a]Institute of applied physics Beijing University of Science and Technology Beijing 100083 China [b]School of Physics Beijing University of Chemical Technology Beijing 100029 China [c]Department of Physics Tsinghua University Beijing 100084 China

A series of lattice inversion pair potentials are used to evaluate the phase stability and site preference for uranium intermetallics UMxAl12 x (M = Fe, Co, Ni, Cr and Mn) and their related hydrides. Calculated results show that Fe, Co, Ni, Cr or Mn atoms preferentially substitute Al at the 8f site. Interstitial H atoms only occupy 2b interstitial sites in UMxAl12 x. Calculated lattice constants are found to agree with a report in the literature. Elastic constants and bulk modulus of UMxAl12 x and UMxAl12 xH were also investigated. In particular, the phonon densities of states (DOS) of these actinide compounds were evaluated for the first time.

关键词： Interatomic potentials Site preference Lattice vibration

NON-EQUILIBRIUM SOLUTE SEGREGATION TO AUSTENITIC GRAIN BOUNDARY IN FERRUM-NICKLE ALLOY

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Acta Metallurgica Sinica(English Letters) 2001年第6期14卷 525-531页

作者： P. wu, D.Y. Yu and X.L. He (department of Material physics, university of science & technology beijing, beijing 100083, china) Dept. of Mat. Phys. Univ. of Sci. and Technol. Beijing Beijing 100083 China

The development of non-equilibrium segregation of boron at grain boundaries in Fe-4 0%Ni alloy during continuous cooling process was experimentally observed with boron Particle Tracking Autoradiography (PTA) and Transmission Electron Microscopy (TEM,). The samples with 10ppm boron were cooled at 2℃/s to 1040, 980, 920, 860, 780 and 640℃ respectively after pre-heat treatment of 1150℃ for 15mm with a Gleeble-1500 heat simulating machine, then water quenched to room temperature. The width of segregation layer and boron depletion zone, rich factor and other parameters were measured by a special image analysis system. The experimental results of PTA show that the grain boundary segregation of boron during cooling process is a dynamic process and the development of the non-equilibrium segregation experiences three stages: first increases rapidly from 1150 to 1040℃, then gently from 1040 to 860℃, and rapidly again from 860℃ to 640℃. The width of boron depletion zone increases from about 11μm at 1040℃ to 26μm at 640℃. TEM observation shows that boron precipitates exist at grain boundaries when the samples are cooled to below 860℃. The experimental phenomena are briefly discussed.

关键词： boron grain boundary non-equilibrium segregation

FRACTAL RESEARCH ON CRACKS PROPAGATION OF GAS PIPELINE X52 STEEL WELDING LINE UNDER HYDROGEN ENVIRONMENT

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Acta Metallurgica Sinica(English Letters) 2001年第3期14卷 219-226页

作者： S.H. Dong , Y.M. Lu, Y. Zhang and Q. wu (Mechanics Electronic department, university of Petroleum, beijing 102200, china) (department of Material physics, university of science and technology beijing, beijing 100083, china) (Yan Shan university, Qinhuangd Dept. of Mech. Electron. Univ. of Pet. Beijing 102200 China

Based on the theory of hydrogen enhanced localized plasticity of the hydrogen induced cracking and the consideration of the effect of the residual stress produced by eliminated stress heat-treatment, a fractal model of hydrogen induced cracking was presented, and the relationships among the effective surface energy (H), fractal dimension D and stress intensity factor of hydrogen induced cracking, KIH, for welding pipeline under hydrogen environment was set up, from which the relationship of D and KISCC was obtained. The model has been verified experimentally to be correct.

关键词： Crack initiation Electric arc welding Environmental impact Fractals Hydrogen

The phase transition and classification of critical points in the multistability chemical reactions

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Communications in Nonlinear science and Numerical Simulation 2000年第1期5卷 36-43页

作者： Chunhua ZHANG Fugen wu Chunyan wu and Fa OU department of physics, Guangdong university of technology, Guangzhou510090, china department of applied physics, South china university of technology, Guangzhou 510641, china department of physics Guangdong University of Technology Guangzhou 510090 China department of applied physics South China University of Technology Guangzhou 510641 China

In this paper, we study the phase transition and classification of critical points in multistability chemical reaction systems. Referring to the spirit of Landau's theory of phase transitions, this paper deals with the varied transitions and critical phenomena in multistable chemical systems. It is demonstrated that the higher the order of the multistability, the wider the variety of phase transitions will be. A classification scheme of critical points according to the stability criterion and the thermodynamic potential continuity is suggested. It is useful for us to study critical phenomena especially in the non-equilibrium systems including the multi-Stable chemical ones.

关键词： nonlinear chemistry non-equilibrium phase transition critical points

THE CHARACTERISTICS OF LASER GENERATED ULTRASOUND IN SOLIDS

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Acta Mechanica Solida Sinica 1997年第3期10卷 189-197页

作者： wu Yaping He Yulong Shi Dufang, department of physics, Huazhong university of science and technology, wuhan 430074, china HUAZHONG UNIV SCI & TECHNOL DEPT PHYSWUHAN 430074PEOPLES R CHINA

The laser generated ultrasound in solids in a thermoelastic regime is studied by solving thermoelastic wave equations. Analytic expressions of two-dimensional far-field ultrasonic displacements including the effects of thermal diffusion and optical penetration were obtained by means of the integral transform method. The meaning of the expressions is discussed. The effects of optical absorption coefficient on the directivity of laser generated ultrasound in non-metallic solids are also discussed. The directivity patterns of both longitudinal waves and shear waves are presented.

关键词： laser generated ultrasound the effect of thermal diffusion the effect of optical penetration directivity relative depth of optical penetration

Quantum Theory of Femtosecond Soliton Propagation in Single-Mode Optical Fibers

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Communications in Theoretical physics 2004年第6期41卷 943-948页

作者： CHEN Shi-Hua ZHANG Shao-wu SHI Du-Fang department of physics,Huazhong university of science and technology,wuhan 430074,china department of physics Huazhong University of Science and Technology Wuhan 430074 China

In this paper we have derived the generalized QNLS equation with considering the third-order dispersion andKerr dispersion,which can be applicable to the femtosecond regime and is suitable for discussing the quantum propertiesof femtosecond solitons in single-mode optical fibers,as compared with its classical *** quantum operatorequation can be solved by many methods such as the linearized perturbations and phase-space ***,owingto the fact that this quantum equation is rather similar to its classical counterpart,all these methods can be facilitatedto a great extent by citing correctly the classical results obtained before.

关键词： generalized QNLS equation single-mode-optical fibers third-order dispersion

THE EFFECTS OF SPUTTERING POWER ON STRUCTURE AND ELECTRICAL PROPERTIES OF Cu FILMS

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Acta Metallurgica Sinica(English Letters) 2002年第2期15卷 215-220页

作者： F.P. Wang. P. wu, L.Q. Pan, Y. Tian and H. Qiu department of physics, school of applied sciences, university of science and technology beijing, beijing 100083, china beijing Keda-Tianyu Microelectronic Material technology Development Co. Ltd., beijing 100 department of physics School of Applied Sciences University of Science and Technology Beijing

Cu films with thickness of about 500nm were deposited on glass substrateswithout heating by DC magnetron sputtering in pure Ar gas of 1.0Pa. The sputtering powers weremaintained at 390V X 0.27A, 430V X 0.70A and 450V X l.04A, and the corresponding deposition rates ofCu film reached 35nm/min, l04nm/min and 167nm/min. X-ray diffraction, scanning electron microscopyand atomic force microscopy were used to observe the structural characteristics of the films. Theresistance of the films was measured using four-point probe technique. The amount of larger grainsincreases and the resistivity of the films decreases evidently with an increase in sputtering *** is considered that the increase in deposition rate with sputtering power mainly weakens theinfluence of residual gas atoms on the growing film, and increases substrate and gas temperatures,resulting in the increase in grain size and the decrease in resistivity of the Cu film.

关键词： Cu film DC magnetron sputtering sputtering power structure resistivity

Ethanol-assisted synthesis of a Ni single-atom catalyst with poriferous 3D framework for efficient cascade CO_(2)electroreduction

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Rare Metals 2024年第9期43卷 4612-4619页

作者： Feng wu Shi-Qi Wang Sebastian Kunze Xiao-ping Gao Pei-Qun Yin Yu-En wu Division of Life sciences and Medicine Department of EndocrinologySchool of Chemistry and Materials ScienceThe First Affiliated Hospital of USTCUniversity of Science and Technology of ChinaHefei 230026China department of Chemistry Seoul National UniversitySeoul 08826South Korea school of Biomedical Engineering Anhui Medical UniversityHefei 230032China

The electroreduction of carbon dioxide to generate multicarbon products is significant for achieving a carbon-neutral ***,the selectivity for multi-carbon products faces several challenges,such as the intricate nature of the multistep hydrogenation processes,slow reaction kinetics and the bicarbonate precipitate issue caused by alkaline *** factors hinder the extensive utilization of this ***,we successfully developed and implemented a tandem electrolyzer cascade to separate and optimize the complex elementary reactions involved in the process of multi-carbon production.

关键词： reaction. synthesis catalyst

The Second Law of Thermodynamics in a Quantum Heat Engine Model

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Communications in Theoretical physics 2006年第3期45卷 417-420页

作者： ZHANG Ting CAI Li-Feng CHEN ping-Xing LI Cheng-Zu department of applied physics,National university of Defence technology,Changsha 410073,chinaCHEN ping-Xing Key Laboratory of Quantum Information,university of science and technology of china,Hefei 230026,china department of applied physics National University of Defence Technology Key Laboratory of Quantum Information University of Science and Technology of China

The second law of thermodynamics has been proven by many facts in classical *** there any newproperty of it in quantum world?In this paper,we calculate the change of entropy in ***’s model for quantumheat engine(QHE)and prove the broad validity of the second law of *** is shown that the entropy ofthe quantum heat engine neither decreases in a whole cycle,nor decreases in either stage of the *** second lawof thermodynamics still holds in this QHE ***,although the modified quantum heat engine is capable ofextracting more work,its efficiency does not improve at *** is neither beyond the efficiency of ***’s initialmodel,nor greater than the reversible Carnot efficiency.

关键词： second law of thermodynamics entropy quantum heat engine