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Optimization of Single or Range of Harmonics by Using Two Gas Jets

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Chinese Physics Letters 2014年第6期31卷 106-108页

作者：李小勇王国利周效信 college of Physics and Electronic Engineering Northwest Normal University Lanzhou 730070 Experimental Center Northwest University for Nationalities Lanzhou 730030

The interference of high-order harmonics generated by two successive gas jets within a single laser pulse is discussed by a modeling with the inclusion of macroscopic propagation of the fundamental and harmonic fields in an ionizing medium. Based on the interference, we show that one can extract the laser Rayleigh range from the interference of harmonics and the accuracy of retrieve is independent of carrier-envelope phase while dependent on the pulse duration. Moreover~ we demonstrate that it is possible to optimize the single or range of harmonics with a high ratio relative to the adjacent orders by changing the separation of two gas jets, which is unavailable by using a single gas jet and linear polarized laser pulse.

关键词： MATHEMATICAL optimization LINEAR polarization OPTICAL polarization RAYLEIGH model POLARIZATION (Nuclear physics) POLARIZATION microscopy

Synthesis and Crystal Structure of a Nickel(Ⅱ) Complex [Ni(H_2btc)_2(hmta)_2(H_2O)] with 1,3,5- Benzenetricarboxylate and Hexamethylenetetramine

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Chinese Journal of Structural Chemistry 2005年第5期24卷 573-575,492页

作者：林鸿冯云龙 Jinhua Professional-technical college Jinhua 321017 China Institute of Physical Chemistry Zhejiang Normal University Jinhua 321004 China

The title compound, Ni(H2btc)2(hmta)2(H2O) (C30H35N8NiO13), has been syn- thesized by the reaction of Ni(CH3COO)2?H2O, 1,3,5-benzenetricarboxylate and hexame-thylene- tetramine in DMF and characterized by X-ray single-crystal diffraction. It crystallizes in the orthor- hombic system, space group Pccn with a = 20.610(4), b = 12.246(2), c = 12.907(3) ?, V = 3257(1) ?3, Z = 4, Mr = 774.37, F(000) = 1612, Dc = 1.579 g/cm3 and μ(MoKα) = 0.677 mm?1. The structure was refined to the final R = 0.0476 and wR = 0.1115 for 3221 observed reflections (I > 2σ(I)). Ni(II) ion is penta-coordinated with two oxygen atoms of monodentate carboxylate groups from two 1,3,5- benzenetricarboxylates, two nitrogen atoms from two hexamethylenetetramines in the equatorial plane, and one water molecule in the axial position. The coordination geometry of Ni(II) can be described as a nearly ideal square-pyramid. Hydrogen bonds exist between the complex molecules, leading to a two-dimensional structure.

关键词： 1,3,5-benzenetricarboxylate hexamethylenetetramine Ni(II) complex crystal structure

5.1-ps passively mode-locked Nd:Gd_(0.42)Y_(0.58)VO_4 laser with a LT-GaAs absorber

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Chinese Optics Letters 2008年第5期6卷 361-363页

作者：刘辉兰孙尧张帅一李涛李健 Department of Physics Dezhou University Qingdao 53rd middle school college of Physics and Electronics Shandong Normal University

We propose a diode end-pumped passively mode-locked Nd：Gd0.42Y0.58VO4 （Nd：GdYVO4） laser at 1064 nm using a GaAs absorber grown at low temperature as the output coupler. Stable continuous-wave （CW） mode locking with a 5.1-ps pulse duration at a repetition rate of 113 MHz is obtained. The maximum average output power is 2.29 W at the incident pump power of 12 W with the slope efficiency of about 24.8%.

关键词： mode CW GaAs ps passively mode-locked Nd Nd LT

Subdiffusion of Dipolar Gas in One-Dimensional Quasiperiodic Potentials

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Chinese Physics Letters 2015年第1期32卷 5-9页

作者：柏小东薛具奎 Key Laboratory of Atomic & Molecular Physics and Functional Materials of Gansu Province College of Physics and Electronics EngineeringNorthwest Normal University

Considering the discrete nonlinear Schrodinger model with dipole-dipole interactions （DDIs）, we comparatively and numerically study the effects of contact interaction, DDI and disorder on the properties of diffusion of dipolar condensate in one-dimensional quasi-periodic potentials. Due to the coupled effects of the contact interaction and the DDI, some new and interesting mechanisms are found： both the DDI and the contact interaction can destroy localization and lead to a subdiffusive growth of the second moment of the wave packet. However, compared with the contact interaction, the effect of DDI on the subdiffusion is stronger. Furthermore and interestingly, we find that when the contact interaction （λ1） and DDI （A2） satisfy λ1 ≥ 2λ2, the property of the subdiffusion depends only on contact interaction; when λ1 ≤ 2λ2, the property of the subdiffusion is completely determined by DDI. Remarkably, we numerically give the critical value of disorder strength v＊ for different values of contact interaction and DDI. When the disorder strength v ≥ v＊, the wave packet is localized. On the contrary, when the disorder strength v ≤ v＊, the wave packet is subdiffusive.

关键词： Subdiffusion of Dipolar Gas in One-Dimensional Quasiperiodic Potentials

Energy Transfer Dynamics between Carbon Quantum Dots and Molybdenum Disulfide Revealed by Transient Absorption Spectroscopy

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化学物理学报(英文) 2023年第5期36卷 503-508,I0001页

作者： Ruixiang Wu Xin Liu Xiaoshuai Wang Jingjing Luo Bin Li Shengzhi Wang Xiangyang Miao Key Laboratory of Spectral Measurement and Analysis of Shanxi Province College of Physics and Information EngineeringShanxi Normal UniversityTaiyuan 030031China

Zero-dimensional environmentally friendly carbon quantum dots(CQDs)combined with two-di-mensional materials have a wide range of applications in optoelec-tronic *** combined steady-state and transient absorp-tion spectroscopies to study the energy transfer dynamics between CQDs and molybdenum disulfide(MoS_(2)).Transient absorption plots showed photoinduced absorption and stimulated emission features,which involved the intrinsic and defect states of *** MoS_(2)to CQDs solution,the lowest unoccupied molecular orbital of CQDs transferred energy to MoS_(2),which quenched the intrinsic emission at 390 *** addition of MoS_(2),CQD-MoS_(2)composites quenched defect emission at 490 nm and upward absorption,which originated from another energy transfer from the defect *** energy transfer paths between CQDs and MoS_(2)were efficiently manipulated by changing the concentration of MoS_(2),which laid a foundation for improving device performance.

关键词： Energy transfer Transient absorption spectroscopy Carbon quantum dot Molybdenum disulfide

Synthesis and Crystal Structure of 4-Azido-2,2,6,6-Tetramethylpiperidine-1-oxyl Free Radical

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Chinese Journal of Structural Chemistry 2006年第2期25卷 127-130页

作者： ZHOU Bao-Han CHEN Yun-Feng YIN Guo-Dong WU An-Xin Key Laboratory of Pesticide and Chemical Biology Ministry of Education College of Chemistry Central China Normal University Wuhan 430079 China

The title compound 4-azido-2,2,6,6-tetramethylpiperidine-l-oxyl （C9H17N4O, Mr = 197.27） has been synthesized and its structure was determined by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P1^- with a = 5.8464（12）, b = 8.2476（17）, c = 11.954（2） A°, a = 101.973（4）, β = 97.186（3）, γ, = 100.232（3）°, V = 546.98（19） ,A°^3, Z = 2, Dc= 1.198 g/cm^3, μ（MoKa） = 0.082 mm^-1, F（000） = 214, R = 0.0495 and wR = 0.1355 for 1677 observed reflections with I 〉 2σ（I）. X-ray analysis reveals that the six-membered ring adopts a chair conformation and the bond length of N（1）-O（1） is 1.2838（19）A°.

关键词： crystal structure nitroxide radical synthesis

Partially Coherent cosh-Gaussian Beams in Atmospheric Turbulence with the Same Directionality as a Laser

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Chinese Physics Letters 2007年第10期24卷 2855-2858页

作者：吕素叶季小玲吕百达 Institute of Laser Physics and Chemistry Sichuan University Chengdu 610064 college of Electronic Engineering Sichuan Normal University Chengdu 610066

Directionality of a class of partially coherent cosh-Gaussian beams propagating in atmospheric turbulence is studied. It is shown that two partially coherent cosh-Gaussian beams may generate the same angular spread, and there exist equivalent partially coherent cosh-Gaussian beams which may have the same directionality as a fully coherent Gaussian laser beam in free space and also in atmospheric turbulence. The theoretical results are interpreted physically and illustrated numerically.

关键词： coated conductor buffer layer self-epitaxy CeO2

Dynamics of An Almost Periodic Solutions for A Non-Autonomous Discrete Competitive System with Feedback Controls

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Journal of Mathematical Research with Applications 2018年第3期38卷 259-275页

作者： Zhouhong LI Li WU Department of Mathematics Yuxi Normal University college of Resource and Environment Yuxi Normal University

This paper investigates the persistence and existence of almost periodic solutions for a discrete competitive system with feedback controls based on the comparison theorem of the difference equation and constructing appropriate Lyapunov function, and several sufficient conditions for the existence of positive almost periodic solutions for the model are ***, a numerical example is given to illustrate effectiveness of our main results.

关键词： persistence almost periodic solution discrete competitive system feedback controls

A Study of Oxalate-Induced Systemic Resistance of Muskmelon to Squash Mosaic Virus

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Advances in Manufacturing 2000年第2期4卷 171-174页

作者： ZHAO Rong le college of Life Sciences, Beijing normal University, Beijing 100875, China college of Life Sciences Beijing Normal University Beijing 100875 China

By treatment with oxalate muskmelon cultivar “Wangwenxiang”, which is sensitive to squash mosaic virus (SqMV), develops systemic resistance to SqMV significantly. The challenge inoculation experiments indicate that the symptom of oxalate treated plants gets much slighter, the virus content is only 4% reduced to. The peroxidase activity increases by five times, three new isoperoxidases are induced, and lignin content increases by 82.9%. These results indicate that oxalate induces systemic resistance of muskmelon to SqMV while it induces increase of peroxidase activity, new isoperoxidases and content of lignin in the plants treated with oxalate.

关键词： oxalate muskmelon squash mosaic virus inductive resistance