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Factorizability of the Two-Component Bose-Einstein Condensate Ground State

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Chinese Physics Letters 1999年第1期16卷 9-11页

作者： HUANG Hu li shi-qun Department of Modern Applied Physics Tsinghua UniversityBeijing 100084 Rochester Theory Center for Optical Science and Engineering University of RochesterRochesterNY 14627USA

In this report the two-component Bose-Einstein condensate ground state is shown to be in factorized form following energy minimization *** argument can also be applied to excited *** implies that for stationary states... 详细信息

关键词： states. argument Einstein

Generation of Squeezed States in Forward Three-Wave Mixing

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Chinese Physics Letters 1998年第2期15卷 109-111页

作者： LÜYa-jun WU ling-an WU Mei-juan li shi-qun Department of Modern Applied Physics Tsinghua UniversityBeijing 100084 Institute of Physics Chinese Academy of SciencesBeijing 100080

We present a study of the generation of squeezed states through nonlinear three-wave mixing in media with an intensity-dependent index of *** the semiclassical model,perfect squeezing for combination modes can be *** the Fokker-Planck equation approach,the effects of pump(including squeezed pump)and loss are *** is shown that the fluctuations of the pump place no fundamental limit to the degree of squeezing obtainable but losses do give an absolute limit.

关键词： absolute squeezed mixing

Control of Cold Atoms by Slow Waves in a Hollow Fibre

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Chinese Physics Letters 2001年第2期18卷 169-171页

作者： li Dai-Jun liU Xia-Ji HUANG Hu li shi-qun WANG Yu-Zhu Department of Physics Tsinghua UniversityBeijing 100084 Laboratory for Laser Energetics University of RochesterRochesterNY 14623-1299 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800

We propose that a slowly-moving standing wave can be used to manipulate the motion of an atomic wave packet in a hollow optical fibre.A cloud of cold atoms can follow the motion of such a slow *** evolution of an initial Gaussian atomic wave packet in the moving standing wave is calculated by numerically solving the Schrödinger *** calculation shows that by using a sufficiently strong field and by adjusting the velocity of the standing wave pattern,the motion of the atomic cloud can be controlled in a hollow fibre.

关键词： equation wave wave

Incoherently Coupled Bright-Dark Soliton Pairs in Biased Centrosymmetric Photorefractive Media

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Chinese Physics Letters 2001年第12期18卷 1607-1609页

作者： HOU Chun-Feng DU Chun-Guang Abdurusul li shi-qun Department of Physics Tsinghua UniversityBeijing 100084 Department of Physics Xinjiang UniversityUrumuqi 830046

It is shown theoretically that incoherently coupled bright-dark soliton pairs can exist in biased centrosymmetric photorefractive media under steady-state conditions. These soliton pairs can be established provided th... 详细信息

关键词： conditions polarization Photorefractive

Nonlinear Theory of light Speed Reduction in a Three-Level Λ System

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Chinese Physics Letters 2001年第8期18卷 1067-1068页

作者： WANG De-Zhong li Dai-Jun liU Xia-J li shi-qun WANG Yu-Zhu Department of Physics Tsinghua UniversityBeijing 100084 Key Laboratory for Quantum Information and Measurements MOEP.R.China Center for Atomic and Molecular Nanosciences Tsinghua UniversityBeijing 100084 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800

We present a nonlinear theory of light velocity reduction in a three-levelΛsystem based on electromagnetically induced *** shows that probe field propagates with a velocity that is quite strongly dependent on its intensity instead of being merely approximately dependent on the coupling ***,the minimum group velocity of the probe field is analytically given for a given input power.

关键词： Nonlinear transparency approximate

Quantum Motion of Atoms in a Magnetic Waveguide

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Chinese Physics Letters 2001年第6期18卷 724-726页

作者： liU Xia-Ji li Dai-Jun WANG De-Zhong HUANG Hu li shi-qun WANG Yu-Zhu Key Laboratory for Quantum Information and Measurements of Education Ministry Department of Physics and Center for Atomic and Molecular NanosciencesTsinghua UniversityBeijing 100084 Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800

Based on the magnetic atomic guidance model proposed in our previous paper[***.160(1999)72],the quantum motion of atoms in a magnetic tube is discussed in *** non-adiabatic loss of atoms as result of spin-flip transition and the adiabatic condition for keeping atoms in the guidable state are also *** result shows that the atoms can be guided in the magnetic waveguide with a higher guiding efficiency by choosing suitable parameters of the magnetic tube.

关键词： waveguide Waveguide adiabatic

Influence of Polluted SY River on Child Growth and Sex Hormones

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Biomedical and Environmental Sciences 2012年第3期25卷 291-296页

作者： TANG Chun Yu li An Qi GUAN Yong Bo li Yan CHENG Xue Min li Ping li shi qun LUO Yi Xin HUANG Qi CHEN Hong Yang CUI liu Xin Department of Environmental Health School of Public Health Zhengzhou University Zhengzhou 450001Henan China School of Basic Medicine Zhengzhou University Zhengzhou 450001 Henan China.

Objective To investigate the influence of the polluted SY River on children＇s growth and sex hormones, and provide scientific data for assessment of the polluted status of the SY River. Methods The study areas were selected randomly from the SY River Basin. Lead （Pb）, mercury （Hg）, arsenic （As）, phthalates （DEP, DBP, DMP, DEHP）, and bisphenol A （BPA） were measured both in the river water and in the drinking water. School children were selected by cluster sampling （n=254）. Physical development indexes （height, weight, bust-circumference, and skinfold thickness） and sex hormones [testosterone （T） and estradiol （E2）] were measured for all the children. Results The contents of Pb and Hg exceeded Class V standards of surface water quality in each section of the river and other indicators exceeded Class Ill. Compared to the control area, the concentrations of Pb, Hg, As, BPA, DEP, and DBP in the drinking water were significantly higher than in the polluted area （P〈0.05）. Children from the control area had significantly lower E2 and T than children from the polluted area （P〈O.05）. Among anthropometric results, only skinfold thickness had statistically significant difference between the two groups （P〈0.05）, while the other indexes showed no significant differences between the two groups （P〉0.05）. Conclusion The drinking water has been polluted by the SY River and affected serum sex hormone levels of children living in the polluted area.

关键词： Water pollution Children Growth and development Estradiol Testosterone

Catalytic asymmetric(3+3)cycloaddition between different 2-indolylmethanols

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Science China Chemistry 2024年第8期67卷 2629-2636页

作者： Tianzhen li Sijia liu Shufang Wu Qi Cheng qun Chen Yinchun Jiao Yuchen Zhang Feng shi School of Petrochemical Engineering School of Materials ScienceEngineeringChangzhou UniversityChangzhou 213164China Research Center of Chiral Functional Heterocycles School of Chemistry and Materials ScienceJiangsu Normal UniversityXuzhou 221116China School of Chemistry and Chemical Engineering Hunan University of Science and TechnologyXiangtan 411201China School of Chemistry and Chemical Engineering Henan Normal UniversityXinxiang 453007China

The catalytic asymmetric(3+3)cycloaddition between different 2-indolylmethanols has been established,in which a series of chiral indole-fused six-membered heterocycles were constructed in high yields with excellent *** work not only has established the first catalytic asymmetric cycloaddition between different 2-indolylmethanols but also provided a powerful strategy for constructing enantioenriched indole-fused six-membered ***,biological evaluation discovered some products with promising antitumor ***,theoretical calculations performed on the reaction pathway and activation mode provide an in-depth understanding of this catalytic asymmetric(3+3)cycloaddition among different 2-indolylmethanols,which will advance the understanding of the chemistry of indolylmethanols.

关键词： asymmetric organocatalysis chiral phosphoric acid cycloaddition enantioselectivity 2-indolylmethanol

The Mixed-Mode Fatigue Crack Propagation Model of Piezoelectric Materials Under Electric Fatigue Loading by the Jk-Integral

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Acta Mechanica Solida Sinica 2024年第4期37卷 634-641页

作者： Xianghua Chen Chunguang Wang qun li The Institute of Xi’an Aerospace Solid Propulsion Technology Xi’an710025China State Key Laboratory for Strength and Vibration of Mechanical Structures School of Aerospace EngineeringXi’an Jiaotong UniversityXi’an710049China

The electric fatigue load has a significant effect on the crack propagation behavior and failure life of piezoelectric materials and devices. In this paper, an electrical mixed-mode fatigue crack propagation model for piezoelectric materials is proposed based on the piezoelectric Jk-integral theory. The crack initiation, propagation, and life prediction criteria of piezoelectric materials under electric fatigue loading are given by this model, and the finite element simulation model is established to study the electrical mixed-mode crack propagation behavior of piezoelectric structures. Meanwhile, the electrical mixed-mode fatigue crack propagation model is applied to the fatigue crack propagation behavior of a piezoelectric typical defective structure, the crack–hole interference model. The mixed-mode crack propagation, fatigue life, and the interference behavior between the crack and hole at various hole locations of the crack–hole interference model are well recognized by this model. The crack propagation behavior under different electrical load intensities is also considered. The results show that the hole in front of the crack tip inhibits crack propagation to a certain extent, and the strength of electrical load affects the fatigue life of piezoelectric materials and structures. Therefore, the proposed electrical mixed-mode fatigue crack propagation model provides a reference for predicting the mixed-mode fatigue crack propagation behavior and fatigue life of piezoelectric structures under electric fatigue loading.

关键词： Configurational force J k-integral Piezoelectric Mixed-mode crack propagation life prediction