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Journal of Rare Earths 2019年第1期37卷 24-31,M0003页

作者： Mohamed Zikriya Y.F.Nadaf P.Vijai Bharathy C.G.Renuka Department of physics Bangalore University Department of physics and Research Center Maharani's Science College for Women Department of physics CBM College

Pure and rare-earth ion (Dy^(3+)) doped TiO_2 nanomaterials were prepared through a chemical coprecipitation method. The chemical composition, micro structure and optical properties were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-visible spectroscopy and photo luminescence (PL). XPS analysis reveals that Dy^(3+)ions are preferentially occupied in the TiO_2 crystallite lattices. Both the XRD and TEM analyses confirm that both the pure and Dy doped TiO_2 are in pure anatase phase and in nano size range, respectively. Also it is found that the maximum solubility limit for Dy^(3+) ions is found to be 0.4%in TiO_2 matrix, above which it occupies interstitials and/or crystallite surface of TiO_2 nanocrystals. From the UV-Vis spectroscopy studies it is found that Dy doping induces blue shift in TiO_2. From the PL analysis it is found that doping Dy^(3+) improves the luminescence behavior in comparison with the pure TiO_2 ***, doping very low concentrations of Dy^(3+) greatly alters the structural morphology and directly increases the luminescence behavior of TiO_2 suitable for advanced optoelectronic applications.

关键词： Rare earth ions TiO2 Dy^3+ion Microstructure Photoluminescence

Effect of residual Doppler averaging on the probe absorption in cascade type system: A comparative study

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Chinese physics B 2018年第9期27卷 287-295页

作者： Suman Mondal Arindam Ghosh Khairul Islam Dipankar Bhattacharyya Amitava Bandyopadhyay Department of physics Visva-Bharati Department of physics Santipur College

Effect of residual Doppler averaging on the probe absorption in an alkali vapor medium in the presence of a coherent pump beam is studied analytically for the Ξ type system. A coherent probe field is assumed to connect the ground level with the intermediate level whereas a coherent control beam is supposed to act between the intermediate energy level and the uppermost level. Optical Bloch equations（OBE） for a three-level Ξ type system and a four-level Ξ type system are derived by using density matrix formalism. These equations are solved by an analytic method to determine the probe response, which not only depends on the wavelength difference between the control（pump） field and the probe field but shows substantially different features depending on whether the wavelength of the control field is greater than that of the probe field or the reverse. The effect of temperature on probe response is also shown. Enhancement in probe absorption and additional features are noticed under a strong probe limit at room temperature. The four-level Ξ type system has two ground levels and this leads to substantial modification in the simulated probe absorption as compared to the three-level system.

关键词： cascade type system density matrix method residual Doppler averaging electromagnetically induced transparency(EIT)

Influence of the ordered structure of short-chain polymer molecule all-trans-β-carotene on Raman scattering cross section in liquid

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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

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

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

Practical approach for detecting k-nonseparability of multipartite quantum states

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Science China(physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 32-48页

作者： Jie Guo Jinchuan Hou Xiaofei Qi Kan He college of Mathematics Taiyuan University of Technology School of Mathematics and Statistics Shanxi University Key Laboratory of Complex Systems and Data Science of Ministry of Education Shanxi University

The instantaneous detection of entanglement in quantum states poses a significant challenge in the fields of quantum computation and quantum information, and there are no practical methods or tools to complete this task satisfactorily so far. We propose a sufficient and necessary criterion of k-nonseparability for any n-partite finite or infinite dimensional systems, 2 ≤ k ≤ n. This criterion serves as the foundation for a practical scheme designed to detect entanglement and k-nonseparability across multipartite finite-dimensional systems. To exemplify the application of our scheme, we have developed a software tool that facilitates swift and precise identification of entanglement, k-nonseparability, and genuine entanglement within n-qubit systems, specifically tailored for systems with 2 ≤ n ≤ 4.

关键词： multipartite systems entanglement states entanglement witnesses ${\bm~k}$-nonseparability

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

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

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