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951.
YONG Wen-Mei WEI Xiu-Fang ZHOU Xiao-Yan XUE Ju-Kui 《理论物理通讯》2009,51(3):433-440
The stability and collective excitation of Bose-Einstein condensates with both two- and three-body interactions in a two-dimensional anhaxmonic trap (i.e., harmonic plus quartic trap) are investigated. By using the variational method, the influence of the three-body interaction and the anharmonicity on the stability axe discussed in detail. It is found that the anhaxmonicity of the trap and the three-body interaction have significant effect on the stability and collective excitations of the system. 相似文献
952.
The viscoelasticity of lipid shell and the hysteresis of subharmonic in liquid containing microbubbles
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The viscoelasticity and subharmonic generation of a kind of lipid ultrasound contrast agent are investigated. Based on the measurement of the sound attenuation spectrum, the viscoelasticity of the lipid shell is estimated by use of an optimization method. Shear modulus GS=10MPa and shear viscosity \mu S=1.49N\cdotS/m2 are obtained. The nonlinear oscillation of the encapsulated microbubble is studied with Church's model theoretically and experimentally.
Especially, the dependence of subharmonic on the incident acoustic pressure is studied. The results reveal that the development of the subharmonic undergoes three stages, i.e. occurrence, growth and saturation, and that hysteresis appears in descending ramp insonation. 相似文献
953.
Application of α——β——γ filtering to real-time atmosphere methane concentration measurement
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A real time $\alpha$--$\beta$--$\gamma$ filtering technique is applied to
the monitoring of atmosphere CH可调二极管激光吸收光谱 谐波检测 物理光学 激光技术 tunable diode laser
absorption spectroscopy, multi-pass cell, harmonic detection Project supported by the National Natural Science Foundation of China (Grant No 10274080) and the
National High Technology Research and Development Program of China (Grant No 2003AA641010). 8/5/2005 12:00:00 AM 2005-08-052006-01-19 A real time α-β-γ filtering technique is applied to the monitoring of atmosphere CH4 based on a tunable diode laser spectrum system operating at 1.654μm. This technique is developed for improving the sensitivity and precision of CH4 concentration measurement with slow concentration change. The effectiveness of this technique is evaluated by performing CH4 concentration measurement and using it to monitor the varying methane level in the atmosphere. It was proved that signal noise ratio enhancement factor is 4.25. The comparison between this filter and moving average is also included in this article. It indicates the advantage of the α-β-γ real time filter. 相似文献
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955.
MIAOYuan-Xiu YANGHong-Yu ZHAIHui CHANGLee 《理论物理通讯》2003,40(1):48-52
We study particles in a vortex state driven to a core state with lower energy and zero angular momentum by the trap potential asymmetries. We find that at T=0 when the role of the thermal gas can be ignored, there will be coexisting condensates. We also calculate the fluctuation of the number difference and argue that in certa/n range of the parameters the state of the whole system is the macroscopic quantum serf-trapping in the Josephson tunnelling regime. 相似文献
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957.
XIAQing-Lin JIANGDong-Chu 《理论物理通讯》2004,42(2):295-298
We introduce a purely anharmonic lattice model with specific double-well on-site potential, which admits traveling compacton-like solitary wave solutions by the inverse method with the help of Mathematica. By properly choosing the shape of the solitary wave solution of the system, we can calculate the parameters of the specific on-site potential. We also found that the localization of the compacton is related to the nonlinear coupling parameter Cn1 and the potential parameter Vo of the on-site potential, and the velocity of the propagation of the compacton is determined by the localization parameter q and the potential parameter Vo. Numerical calculation results demonstrate that the narrow compacton is unstable while the wide compacton is stable when they move along the lattice chain. 相似文献
958.
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960.
非对称量子阱中的二阶非线性光学极化率 总被引:4,自引:1,他引:3
本文主要研究了一个特殊非对称量子阱中的二阶非线性光学极化率,并且利用量子力学中的密度矩阵算符理论和迭代方法导出了二次谐波极化率的解析表达式.最后,以典型的GaAs/AlGaAs非对称量子阱为例作了数值计算.数值结果表明,较大的二次谐波极化率与系统的非对称性有关,系统的非对称性越大,二次谐波极化率越大. 相似文献