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定向电场下W_(6)C_(6)团簇的超卤素调制及非线性光学特性

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原子与分子物理学报 2025年第3期42卷 72-76页

作者：蔡璧钧段宇静魏强重庆理工大学理学院重庆400050

本文采用密度泛函(DFT)方法研究了定向外电场(OEEF)对W_(6)C_(6)团簇几何结构、电子性质以及非线性光学响应(NLO)的影响.计算结果表明W_(6)C_(6)的结构在一定OEEF强度下可以保持稳定.OEEF可以增大W_(6)C_(6)团簇的电子亲和能(EA值),且... 详细信息

本文采用密度泛函(DFT)方法研究了定向外电场(OEEF)对W_(6)C_(6)团簇几何结构、电子性质以及非线性光学响应(NLO)的影响.计算结果表明W_(6)C_(6)的结构在一定OEEF强度下可以保持稳定.OEEF可以增大W_(6)C_(6)团簇的电子亲和能(EA值),且在特定强度下,OEEF可以将W_(6)C_(6)团簇转变为超卤素.通过对EA值的非线性拟合可以实现对W_(6)C_(6)团簇的连续调制.进一步对不同外电场下W_(6)C_(6)团簇的最高占据分子轨道(HOMO)和最低未占据分子轨道(LUMO)能级进行分析,发现OEEF降低了W_(6)C_(6)团簇LUMO能级是其EA值增大的主因.此外,OEEF可以显著增大W_(6)C_(6)团簇的平均极化率和第一超极化率,尤其是第一超极化率,改变其非线性光学性质.

关键词：定向外电场超原子密度泛函理论 NLO W_(6)C_(6)团簇

维普期刊数据库博看期刊

Oxidation behavior of a kind of carbon black

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Science China(Technological Sciences) 2009年第6期52卷 1535-1542页

作者： JunShi Tang qiang Song BaiLei He qiang Yao Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Thermal Engineering Tsinghua University Beijing 100084 China

The DTG curves of a kind of carbon black during TPO tests were found to have multiple peaks with an unusual sharp peak after the main *** tests with different sample loads,oxygen fractions and heating rates were carried out to study the influence of the experimental parameters on the sharp *** results show that the sharp peak is not caused by heat and mass transfer limitations,but by the intrinsic oxidation kinetics of the carbon *** evolution of the specific surface area during the intrinsic kinetic controlled oxidation process was then analyzed using isothermal oxidation at low temperatures which showed that the sharp peak is caused by the increase of the specific surface *** pore structure changes greatly influence the oxidation process when the reaction is controlled by the intrinsic *** there were no heat and mass transfer limitations,the different oxidation processes result in the same specific surface area evolution.

关键词： thermal analysis carbon black multiple peaks specific surface area

Theoretical dispersion curves for borehole real-valued wave modes in vertically transverse isotropic formations

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Petroleum Science 2022年第6期19卷 2649-2662页

作者： Fu-qiang Zeng Chao Li Hubei Subsurface Multi-scale Imaging Key Laboratory Institute of Geophysics and GeomaticsChina University of GeosciencesWuhan430074HubeiChina State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing100190China Beijing Engineering and Technology Research Center for Deep Drilling Exploration and Measurement Beijing100190China

The dispersion curves of real-valued modes in a fluid-filled borehole are widely used in acoustic well *** accurate dispersion curves are the precondition of theoretical analysis and inversion ***,these curves can be obtained by solving the conventional dispersion equation for isotropic formations and most vertically transverse isotropy(VTI)***,if the real-valued solutions exist when the radial wavenumbers for the formation quasi-P and quasi-S equals to each other,the existed methods based on the conventional dispersion equation could lead to incorrect results for some VTI *** studies have focused on the influence of these real-valued solutions on dispersion curve *** remove these real-valued solutions,we have proposed a modified dispersion equation and its corresponding solving *** solving the dispersion equation,the Scholte wave velocity of VTI formation at high frequency is used as the initial *** two synthetic examples including fast and slow VTI formations validate that these real-valued solutions do not contribute to the wavefield,and the new dispersion curve extraction method is suitable for all kinds of VTI ***,the method can provide reliable dispersion curves for both theoretical analysis and anisotropic parameters inversion in VTI formations.

关键词： Dispersion equation Scholte wave velocity Acoustic properties Transverse isotropy Thomsen anisotropic parameters inversion

Effect of Fe2O3 on the size and components of spinel crystals in the CaO–SiO2–MgO–Al2O3–Cr2O3 system

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1113-1119页

作者： Qi-qiang Mou Jian-li Li qiang Zeng Hang-yu Zhu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China

size of spinel crystals in the CaO–SiO2–MgO –Al2O3–Cr2O3 system was investigated using lab experiments carried out in a carbon tube furnace. Scanning electron microscopy with energy-dispersive X-ray spectroscopy（SEM–EDS） and X-ray diffraction（XRD） were used to analyze the microstructure, components, and the mineral phases of synthetic slags. FactS age 7.1 was used to calculate the crystallization process of the molten slag. The results showed that the addition of Fe2O3 promoted the precipitation of spinel crystals and inhibited the formation of dicalcium silicate. The size of spinel crystals increased from 2.74 to 8.10 μm and the contents of chromium and iron in the spinel varied as the Fe2O3 addition was increased from 0 to 20 wt%. Fe2O3 thermodynamically provided the spinel-forming components to enhance the formation of FeCr2O4, MgFe2O4, and Fe3O4. The addition of Fe2O3 increased the fraction of liquid phase in a certain temperature range and promoted diffusion by decreasing the slag’s viscosity. Therefore, Fe2O3 is beneficial to the growth of spinel crystals in stainless steel slag.

关键词： ferric oxide stainless steel slag spinel crystal size chromic oxide

Mean-square Stability of Stochastic Age-dependent Delay Population Systems with Jumps

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Acta Mathematicae Applicatae Sinica 2018年第1期34卷 145-154页

作者： qiang LI Qi-min ZHANG Bo-qiang CAO School of Mathematics and Statistics Ningxia University Yinchuan 750021 China School of Mathematics and Information Sciences Beifang University of Nationalities Yinchuan 750021 China

In this paper, we present the compensated stochastic θ method for stochastic age-dependent delay population systems（SADDPSs） with Poisson jumps. The definition of mean-square stability of the numerical solution is given and a sufficient condition for mean-square stability of the numerical solution is derived. It is shown that the compensated stochastic θ method inherits stability property of the numerical solutions. Finally,the theoretical results are also confirmed by a numerical experiment.

关键词： stochastic age-dependent delay population systems compensated stochastic θ method poisson jumps mean-square stability

Rees-Shishikura's Theorem for Geometrically Finite Rational Maps

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Acta Mathematica Sinica,English Series 2017年第12期33卷 1587-1596页

作者： Wen qiang SHEN Department of Mathematical Sciences Tsinghua University Beijing 100084 P. R. China

In this paper, we generalize Rees-Shishikura＇s theorem to the class of geometrically finite rational maps.

关键词： Geometrically finite rational map Rees-Shishikura's theorem homeomorphism

The Semiclassical Limit in the Quantum Drift-Diffusion Model

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Acta Mathematica Sinica,English Series 2009年第2期25卷 253-264页

作者： qiang Chang JU Institute of Applied Physics and Computational Mathematics P. O. Box 8009-28 Beijing 100088 P. R. China

Semiclassical limit to the solution of isentropic quantum drift-diffusion model in semicon- ductor simulation is discussed. It is proved that the semiclassical limit of this solution satisfies the classical drift-diff... 详细信息

关键词： quantum drift-diffusion weak solution semiclassical limit isentropic

Exact Values of Some Geometric Constants of Orlicz Spaces

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Acta Mathematica Sinica,English Series 2007年第5期23卷 827-846页

作者： Ya qiang YAN Department of Mathematics Suzhou University Suzhou 215006 P. R. China

We present the exact values of nonsquare constants, von Neumann-Jordan constants, Jung constants, packing constants, weakly convergent sequence coefficients and normal structure coefficients in a class of reflexive Or... 详细信息

关键词： Banach space Orlicz space geometric constant

The Compressibility of Checkerboard Surfaces of Link Diagrams

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Acta Mathematica Sinica,English Series 2007年第10期23卷 1845-1858页

作者： Zhi qiang BAO LMAM School of Mathematical Sciences Peking University Beijing 100871 P. R. China

Consider the checkerboard surfaces defined by some link diagrams. When they are not orientable, one considers the boundary surfaces of small regular neighborhoods of them. This article studies the compressibility problem of these kinds of surfaces in the link complements. The problem is solved by devising a normalization theory for the compressing discs, which brings up an algorithm to read out compressibility directly from the link diagrams. As an application of the algorithm, the compressibility changes under Reidermeister moves are studied. Diagrams from the knot tables are also studied, and surprisingly, some of them are shown to define completely compressible surfaces of this kind. Infinitely many examples of non-alternating knot diagrams with incompressible surfaces of this kind are also constructed.

关键词： compressibility checkerboard surface knot diagram