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Chinese physics B 2011年第3期20卷 444-449页

作者：曲冠男欧阳顺利王微微里佐威孙成林门志伟 State Key Laboratory of Superhard Materials College of PhysicsJilin University college of physics Jilin University

We measured the resonant Raman spectra of all-trans-β-carotene in solvents with different densities and concentrations at different temperatures. The results demonstrated that the Raman scattering cross section （RSCS） of short-chain polymer all-trans-β-carotene is extremely high in liquid. Resonance and strong coherent weakly damped CC bond vibrating properties play important roles under these conditions. Coherent weakly damped CC bond vibration strength is associated with molecular ordered structure. All-trans-β-carotene has highly ordered structure and strong coherent weakly damped CC bond vibrating properties, which lead to large RSCS in the solvent with large density and low concentration at low temperature.

关键词： Raman scattering cross-section polymer molecule ordered structure

First-principles study of He trapping in η-Fe_2C

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Chinese physics B 2016年第11期25卷 412-417页

作者：赫丙玲王金龙田之雪蒋利娟宋薇王斌 college of physics and Electronic Engineering Xinxiang University college of physics and Information Engineering Hebei Normal University

The distribution of He in η-Fe2C has been studied by first-principles *** formation energies of interstitial He and substitutional He（replacing Fe） are 3.76 eV and 3.49 eV,respectively,which are remarkably smaller than those in bcc Fe,indicating that He is more soluble in η-Fe2C than in bcc *** binding potencies of both a substitutionalinterstitial He pair（1.28 eV） and a substitutional-substitutional He pair（0.76 eV） are significantly weaker than those in bcc *** binding energy between the two He atoms in an interstitial-interstitial He pair（0.31 eV） is the same as that in bcc Fe,but the diffusion barrier of interstitial He（0.35 eV） is much larger than that in bcc Fe,suggesting that it is more difficult for the interstitial He atom to agglomerate in η-Fe2C than in bcc ***,self-trapping of He in η-Fe2C is less powerful than that in bcc *** a consequence,small and dense η-Fe2C particles in ferritic steels might serve as scattered trapping centers for He,slow down He bubble growth at the initial stage,and make the steel more swelling resistant.

关键词： interstitial trapping Fe_2C powerful dense steels scattered octahedral swelling consequence

Origin of diffraction fringes in two-dimensional photoelectron momentum distributions for single ionization of atoms in few-cycle intense laser pulses

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Chinese physics B 2014年第4期23卷 223-229页

作者：郭志坚陈长进周效信 college of physics and Electronic Engineering Northwest Normal University Department of physics College of Science Shantou University

We use the strong field approximation with a time window function controlling the release time of electrons to study the intra-cycle and inter-cycle interferences in few-cycle intense laser pulses impinging on He. The diffraction fringes, i.e., the vertical stripe-like structure, observed in the experimental two-dimensional photoelectron momentum distributions of Gopal et al. （2009 Phys. Rev. Lett. 103 053001） have been attributed to the interplay of the intra- and inter-cycle interferences. The pure numerical calculations by solving the time-dependent Schrrdinger equation are also performed and the results are compared with the experimental measurements directly. It has been found that the position of the stripe-like structure can be used to determine the duration of the laser pulses used in experiments.

关键词： intra-cycle and inter-cycle interferences stripe-like structure two-dimensional momentum distri- butions

Structural and photoluminescence properties of terbium-doped zinc oxide nanoparticles

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Chinese physics B 2014年第5期23卷 607-611页

作者： Ningthoujam Surajkumar Singh Shougaijam Dorendrajit Singh Sanoujam Dhiren Meetei Department of physics Manipur UniversityCanchipur Department of physics Pachhunga University CollegeCollege Veng

We present in this paper a study of the structural and photoluminescence （PL） properties of terbium （Tb） doped zinc oxide （ZnO） nanoparticles synthesized by a simple low temperature chemical precipitation method, using zinc acetate and terbium nitrate in an isopropanol medium with diethanolamine （DEA） as the capping agent at 60 ℃. The as-prepared samples were heat treated and the PL of the annealed samples were studied. The prepared nanoparticles were characterized with X-ray diffraction （XRD）. The XRD patterns show the pattern of typical ZnO nanoparticles and correspond with the standard XRD pattern given by JCPDS card No. 36-1451, showing the hexagonal phase structure. The PL intensity was enhanced due to Tb^3＋ doping, and it decreased at higher concentrations of Tb^3＋ doping after reaching a certain optimum concentration. The PL spectra of Tb^3＋ doped samples exhibited blue, bluish green, and green emissions at 460 nm （5^D3 - 7^F3）, 484 nm （5^D4 - 7^F6）, and 530 nm （5^D4 - 7^F5）, respectively, which were more intense than the emissions for the undoped ZnO sample. Based on the results, an energy level schematic diagram was proposed to explain the possible electron transition processes.

关键词： zinc oxide nanoparticles photoluminescence chemical precipitation

The Efect of the Earthed Electrode Size on the Ignition Voltage of Low-Pressure RF Capacitive Discharge in Argon

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Plasma Science and Technology 2013年第9期15卷 881-884页

作者： A. A. AZOOZ M. A. AHMAD Department of physics College of ScienceMosul University Department of physics College of EducationMosul University

The effect of the grounded electrode diameter on the ignition voltage using 13.56 MHz in argon gas is studied experimentMly. The results indicate a systematic decrease of the breakdown voltage with increasing electrode area for the same pd value. No multi-valued breakdown voltages are observed. The Paschen minimum is not affected by the electrode diameter as long as the parallel plane approximation is valid. A modified Paschen equation which takes into account indirect discharge via the chamber walls at high pd values gives reasonable fits to the experimental data.

关键词： CCRF electrode size Paschen law RF plasma

Calculation of scattering parameters for ultracold ~6 Li-~7 Li elastic collisions

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Chinese physics B 2011年第2期20卷 216-219页

作者：张计才孙金锋刘玉芳 college of physics and Information Engineering Henan Normal University Department of physics Luoyang Normal College

This paper theoretically studies the elastic scattering properties in a mixture of 6Li and 7Li atoms at cold and ultracold temperatures. Based on the constructed accurate interatomic potential of the triplet state for 6Li7Li mixture by the mass scaling method, it calculates the interspecies s-wave scattering lengths and the p-wave scattering lengths by the variable phase method and the semiclassical method, respectively. The scattering length is in good agreement with the experiment. The partial-wave and total cross sections are also calculated and a rich resonance structure is found.

关键词： scattering length elastic cross section variable phase method

Spin transport properties in double quantum rings connected in series

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Journal of Semiconductors 2011年第2期32卷 1-5页

作者：杜坚王素新潘江洪 Department of physics Hebei Normal college for Nationalities college of physics and Technology Guangxi Normal University

A new model of metal/semiconductor/metal double-quantum-ring connected in series is proposed and the transport properties in this model are theoretically studied. The results imply that the transmission coefficient shows periodic variations with increasing semiconductor ring size. The effects of the magnetic field and Rashba spin-orbit interaction on the transmission coefficient for two kinds of spin state electrons are different. The number of the transmission coefficient peaks is related to the length ratio between the upper arm and the half circumference of the ring. In addition, the transmission coefficient shows oscillation behavior with enhanced external magnetic field, and the corresponding average value is related to the two leads＇ relative position.

关键词： transmission coefficient double quantum rings Rashba spin-orbit interaction

Elastic scattering of sodium and cesium atoms at ultracold temperatures

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Chinese physics B 2011年第9期20卷 171-174页

作者：张计才王克栋刘玉芳孙金锋 college of physics and Information Engineering Henan Normal University Department of physics Luoyang Normal College

The elastic scattering properties in a mixture of sodium and cesium atoms are investigated at cold and ultracold temperatures. Based on the accurate interatomic potential for the NaCs mixture, the interspecies s-wave scattering lengths, the effective ranges and the p-wave scattering lengths are calculated by the quantal method and the semiclassical method, respectively. The s-wave scattering lengths are 512.7a0 for the singlet state and 33.4a0 for the triplet state. In addition, the spin-change and elastic cross sections are also calculated, and the g-wave shape resonance is found in the total elastic cross sections.

关键词： elastic scattering s-wave scattering length spin-change cross section

Calculation of the elastic collision properties of Na and Li atoms at ultracold temperature

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Chinese physics B 2009年第4期18卷 1486-1490页

作者：张计才张莹杜丙阁孙金锋 college of physics and Information Engineering Henan Normal University Department of physics Luoyang Normal College

This paper firstly reports a theoretical study of elastic scattering properties in a mixture of 23Na and 7Li atoms at cold and ultracold temperatures in detail. Based on the new constructed accurate singlet X1∑g＋ and the triplet a3∑u＋ states interatomic potentials for 23Na7Li mixture, it calculates the scattering lengths and the effective ranges by three computational methods, and obtains good agreements. Using the mass scaling method, it also calculates 23Na6Li scattering lengths and s-wave and total elastic cross sections, whose rich resonance structures were found and interpreted in terms of quasibound diatomic levels trapped behind a centrifugal barrier.

关键词： scattering length elastic cross section variable phase method

Differences in the adsorption of FePc on coinage metal surfaces

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Chinese physics B 2013年第6期22卷 306-313页

作者： R.A.Rehman 蔡亦良张寒洁吴珂窦卫东李海洋何丕模鲍世宁 physics Department Zhejiang University physics Department Forman Christian College UniversityLahore-Pakistan physics Department Forman Christian College University

A study of the electronic and structural properties of iron phthalocyanine （FePc） molecules adsorbed on coinage metal surfaces Cu （100） and Cu （110） has been conducted by means of density functional theory calculations. The strength of the molecule-substrate interactions is interpreted in terms of the lateral adsorption geometry and the site specific electronic structure of the molecule. In the case of FePc on a （100）-oriented copper surface, the benzopyrrole leg is found to be oriented at an angle of 9°or 3°from the [01-1] substrate direction. Further, an upward bend in the molecular plane ranging from 7° to 10°is also observed; giving an almost buckled shape to the molecule. However, in the case of FePc on Cu （110）, neither a bend nor a sizable rotation is observed. From the knowledge of the principle structural and electronic properties, it is concluded that FePc-Cu （100） interaction is relatively stronger than FePc-Cu （110） interaction, which is further evidenced by the charge transfer, work function changes, changes in the shape of the adsorbed molecular orbitals, and the orbital shifts. Furthermore, density of states analysis shows that the valence band level shift is surface- and site-dependent.

关键词： iron phthalocyanine copper electronic and structural properties density functional theory