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Chinese Physics Letters 2008年第2期25卷 597-600页

作者：杨焱吴冠豪余永亮童秉纲 The Laboratory for Biomechanics of Animal Locomotion Graduate University of Chinese Academy of Sciences Beijing 100049 Department of Modern Mechanics University of Science and Technology of China Hefei 230026 State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instruments Tsinghua University Beijing 100084

We present （1） the dynamical equations of deforming body and （2） an integrated method for deforming body dynamics and unsteady fluid dynamics, to investigate a modelled freely self-propelled fish. The theoretical model and practical method is applicable for studies on the general mechanics of animal locomotion such as flying in air and swimming in water, particularly of free self-propulsion. The present results behave more credibly than the previous numerical studies and are close to the experimental results, and the aligned vortices pattern is discovered in cruising swimming.

关键词： pulsars x-ray spectra relativity and gravitation redshift

Thermocapillary Convection in an Inhomogeneous Porous Layer

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Chinese Physics Letters 2008年第2期25卷 620-623页

作者：赵思诚刘荣刘秋生 Institute of Mechanics Chinese Academy of Sciences Beijing 100080

A new model consisting of an inhomogeneous porous medium saturated by incompressible fluid is investigated. We focus on the effects of inhomogeneity for the streamline patterns and instabilities of the system. Influences of the ＇mean porosity＇ and gradient of distributions of porosity are also emphasized. The results cannot be obtained by studying the media with constant porosity as carried out by other researchers, and have not been discussed before.

关键词： pulsars x-ray spectra relativity and gravitation redshift

Plasmon-Assisted Phase-Matched Second- and Third-Harmonic Generation in Single-Negative Heterostructures

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Chinese Physics Letters 2008年第1期25卷 274-277页

作者：喻小强周林朱永元祝世宁 National Laboratory of Solid State Microstructures Nanjing University Nanjing 210093 Department of Physics Nanjing Xiaozhuang College Nanjing 210017

Dispersion relations of surface plasmon polaritons （SPPs） in sandwiched optical systems are studied. The system is actually a kind of SPP waveguides, with two kinds of single negative material （SNG） as core and cladding layers, respectively. Since both TM and TE polarized SPPs can be excited in the structure, the dispersion of SPPs becomes more abundant and leads to colorful nonlinear opticM properties. The authors demonstrate the effective phase-matched second and third-harmonic generation （SHG, THG） assisted by the coupled SPPs. A cascaded second-order nonlinear process can Mso be achieved in the structure when the thickness of the core layer is properly selected, leading to the simultaneous SHG and THG. Further investigations show that much easier phase-matching can be fulfilled in the SNG waveguide array. Our results would be of potential use for surface-enhanced frequency conversion device such as light emitters or lasers.

关键词： pulsars x-ray spectra relativity and gravitation redshift

Eye-Safe Raman Laser at 1.5μm Based on BaWO4 Crystal

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Chinese Physics Letters 2008年第1期25卷 122-124页

作者：王正平胡大伟方新张怀金许心光王继扬邵宗书 State Key Lab of Crystal Materials Shandong University Jinan 250100 Jiangsu Shuguang Opto-electronics Co. Ltd. Yangzhou 225009

Using an external couple cavity and a pump beam compression system, efficient 1.5 μm eye-safe Raman laser is obtained based on BaWO4 crystal. The largest output energy is 8.5mJ, corresponding to an electric-optical c... 详细信息

关键词： pulsars x-ray spectra relativity and gravitation redshift

Efficient Laser-Diode End-Pumped Passively Q-Switched Mode-Locked Yb：LYSO Laser Based on SESAM

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Chinese Physics Letters 2008年第2期25卷 548-551页

作者：徐世祥李文雪郝强翟惠曾和平 State Key Laboratory of Precision Spectroscopy and Department of Physics East China Normal University Shanghai 200062

We report an efficient Q-switched laser action based on a semiconductor saturable absorber mirrors （SESAMs） as passively Q-switched laser starter and a Yb：LYSO alloyed crystal as gain material pumped directly by 974nm InGaAs laser diodes. The output pulse duration is measured to be about 7μs, while the average power and the repetition rate of the pulse chain are about 0.92 W and 6.2 kHz, respectively, under 12.5 W absorbed pumping power. The Q-switched mode-locked pulse train is also observed in this setup. The laser performance shows that Yb：LYSO is a promising laser gain medium for laser-diode pumped compact solid-state lasers.

关键词： pulsars x-ray spectra relativity and gravitation redshift

Dynamical Attractor of Modified Chaplygin Gas

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Chinese Physics Letters 2008年第1期25卷 347-350页

作者：贺敬吴亚波付明慧 Department of Physics Liaoning Normal University Dalian 116029

The dynamical attractor of the modified Chaplygin gas （MCG） model is studied. The dynamical analysis indicates that the phase ωMCG = -1 is a dynamical attractor and the equation of state of the MCG approaches it from either ωMCG 〉 -1 or ωMCG 〈 -1, independent of the choice of its initial density parameter and the ratio of pressure to critical energy density. Therefore our universe will not end up with Big Rip in the future. Moreover, the evolutions of the density parameters Ωγ and ΩMCG are quite different. For different initial values of x and y, Ωγ decreases and ΩMCG increases as time increases, and they will eventually approach Ωe = 0 and ΩMCG = 1, i.e., de Sitter phase. This implies that when there is not the interaction （i.e., the energy transfer） between the barotropic background fluid and modified Chaplygin gas （MCG）, the behaviour of the MCG will be similar to ACDM in the future.

关键词： pulsars x-ray spectra relativity and gravitation redshift

PIV Measurements and Mechanisms of Adjacent Synthetic Jets Interactions

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Chinese Physics Letters 2008年第2期25卷 612-615页

作者：罗振兵夏智勋 College of Aerospace and Material Engineering National University of Defense Technology Changsha 410073

Interactions of adjacent synthetic jet actuators with varying relative amplitude and the relative phase of driving voltage are measured using a particle image velocimetry （PIV）. Varying relative amplitude or relative phase of driving voltage of the adjacent actuators vectors the direction of the ensuing merged jet of the adjacent synthetic jets. The vectoring mechanism of the adjacent vortex pairs, attract-impact causing deflection （AICD）, is provided to explain why the merged jet is generally vectored to the side of the phase-leading synthetic jet or the synthetic jet with higher driving voltage.

关键词： pulsars x-ray spectra relativity and gravitation redshift

Quantum Fluids of Self-Assembled Chains of Polar Molecules at Finite Temperature

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Chinese Physics Letters 2008年第1期25卷 48-51页

作者：朱坤雁谭磊高翔王道维 Department of Physics Lanzhou University Lanzhou 730000 Department of Physics National Tsing-Hua University Hsinchu Taiwan

The finite temperature properties of self-assembled dipole chains of polar molecules in strongly confined pancake traps are investigated. The single-chain vibrations at finite temperature, which become important for long chains in a strongly interacting regime, are found to lower the transition temperature and to shift the chain distribution by less than 10%. We also propose experimental parameters to observe such quantum phase transition.

关键词： pulsars x-ray spectra relativity and gravitation redshift

An All-Thin-Film Electrochromic Device Composed of MoO3-LiBSO-NiOx Multilayer Structure

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Chinese Physics Letters 2008年第2期25卷 740-742页

作者：杨海刚王聪朱开贵刁训刚王怀义崔毅王天民 Center for Condensed Matter and Materials Physics School of Science Beihang University Beijing 100083

An all-thin-tilm （ATF） electrochromic device for modulating the optical transmittance is manufactured using magnetron sputtering. The devices consists of MoO3 as the main electrochromic layer, LiBO2 ＋Li2SO4 （LiBSO） as the ion conductor layer, and NiOx as the complementary electrochromic layer. Glass covered with indium tin oxide （ITO） is used as the substrate and the ITO film is used as the bottom electrode. The ITO film deposited on the top of the devices is used as the other electrode. The structure and morphology of the films are characterized by x-ray diffraction （XRD） and scanning electron microscopy （SEM）. The devices exhibit good optical properties with low transmittance values in the coloured state, and the optical modulation is measured by spectrophotometer in the wavelength range from 400 to 800nm. The average visible light transmittance reaches 50.2% and 3.7% in bleached and coloured state, respectively. The results indicate that such a monolithic system has great potential to be applied in smart windows.

关键词： pulsars x-ray spectra relativity and gravitation redshift

Partial Transposition on Bipartite System

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Chinese Physics Letters 2008年第1期25卷 35-38页

作者：任喜军韩永建吴玉椿郭光灿 Key Laboratory of Quantum Information University of Science and Technology of China Hefei 230026

Many properties of partial transposition are unclear as yet. Here we carefully consider the number of the negative eigenvalues of ρ^T （ρ＇s partial transposition） when p is a two-partite state. There is strong evidence to show that the number of negative eigenvalues of ρ^T is N（N - 1）/2 at most when ρ is a state in Hilbert space C^N × C^N. For the special case, the 2 × 2 system, we use this result to give a partial proof of the conjecture ｜ρ^T｜^T ≥0. We lind that this conjecture is strongly connected with the entanglement of the state corresponding to the negative eigenvalue of ρ^T or the negative entropy of ρ.

关键词： pulsars x-ray spectra relativity and gravitation redshift