排序方式: 共有39条查询结果,搜索用时 11 毫秒
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报道在带阻尼参数激励下的一维非线性点阵中所观察到的非传播孤子现象。并在理论上采用多重尺度展开法把同相和错相的孤子与扭结实验结果归入立方非线性Schr?dinger方程的理论框架。根据非线性Schr?dinger方程,我们预言在这种实验点阵中,自局域结构的波型只取决于点阵的固有参量,而与激励参数无关。
关键词: 相似文献
22.
Wei-Zhong Chen 《中国物理 B》2022,31(2):28503-028503
A novel 4H-SiC merged P-I-N Schottky (MPS) with floating back-to-back diode (FBD), named FBD-MPS, is proposed and investigated by the Sentaurus technology computer-aided design (TCAD) and analytical model. The FBD features a trench oxide and floating P-shield, which is inserted between the P+/N-(PN) junction and Schottky junction to eliminate the shorted anode effect. The FBD is formed by the N-drift/P-shield/N-drift and it separates the PN and Schottky active region independently. The FBD reduces not only the Vturn to suppress the snapback effect but also the Von at bipolar operation. The results show that the snapback can be completely eliminated, and the maximum electric field (Emax) is shifted from the Schottky junction to the FBD in the breakdown state. 相似文献
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该文介绍了声空化液体中声波被反常吸收的现象,即驱动声压越大,吸收越强,远场声压越低。研究给出其物理机理是高声压导致强空化,空化泡吸收驱动能量辐射高次谐波,高频声波更易被液体吸收,最终形成更低的远场声压。为了克服空化屏蔽,改善声空化的均匀性,提出了改变工作液体的空化阈值的思路。并就简单的双层液体系统进行了计算和实验,结果证实这种思路的正确性。 相似文献
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A non-adiabatic model of single bubble sonoluminescence has been advanced through considering the energy dissipation caused by light emission. The bubble dynamical equations with a black-body radiation have been solved numerically. The results show that without introduciag any model parameter, this model not only can well reproduce the experimental phenomena in the time scale of microsecond of the adiabatic model can do, but also can obtain a 40-100 ps of flash duration and a 104 K effective temperature of the black-body radiation. These agree with the experiment quite well. 相似文献
26.
Lingling Zhang 《中国物理 B》2022,31(4):44303-044303
The pulsations and translations of cavitation bubbles obey combined ordinary differential equations, and their nonlinearities are studied by the bifurcation diagram and the phase diagram in a strong ultrasonic field. Bubble pulsation can change regularly or irregularly with changing driving pressure in the time domain. The bifurcation diagrams of the pulsation versus driving pressure show that the pulsations and translations of bubbles have nonlinear characteristics, and the nonlinear translations of bubbles can disorder the pulsations for certain parameters. Disorder of the pulsation can also be caused by nonlinear pulsation itself. In addition, the phase diagrams also show that the nonlinear translations make a large contribution to the pulsations. The same result can also be obtained when the ambient radii of two bubbles are different. 相似文献
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运用长距离显微成像系统与锁相积分拍摄技术相结合的方法, 拍到了单个造影剂微泡在两种不同频率和不同声压下的周期性振动图像. 根据这些图像得到了微泡直径的实验数据, 并分别用Hoff模型和Rayleigh-Plesset模型对数据进行拟合, 并对数据进行了频谱分析. 结果表明:Hoff模型对实验数据的拟合结果优于Rayleigh-Plesset模型的拟合结果; 二次谐波的相对强度随着声压幅度的升高而增大.
关键词:
包膜微泡
锁相积分拍摄方法
频谱 相似文献
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Dynamics of a single cavitation bubble in sodium dodecyl sulfate(SDS) aqueous solutions is investigated experimentally and theoretically. The bubble pulsation is measured by a phase-locked integrated imaging technique,and the ambient radius is obtained by fitting the numerical calculation based on the Rayleigh–Plesset bubble dynamics model to the experimental data. The results show that, under the same driving condition, the ambient radius of the cavitation bubble decreases correspondingly with the increase of SDS concentration within the critical micelle concentration, while the compression ratio of the radius increases, which indicates that the addition of SDS decreases the internal molecular number of the cavitation bubble and increases the power capability of the cavitation bubble. In addition, bubble oscillation increases the concentration of the surfactant molecules on the bubble wall, so that the effect of SDS on a single cavitation bubble is reduced when the SDS concentration is greater than 0.8 m M. 相似文献
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A novel shorted anode lateral-insulated gate bipolar transistor(SA LIGBT)with snapback-free characteristic is proposed and investigated.The device features a controlled barrier Vbarrierand resistance RSAin anode,named CBR LIGBT.The electron barrier is formed by the P-float/N-buffer junction,while the anode resistance includes the polysilicon layer and N-float.At forward conduction stage,the Vbarrierand RSAcan be increased by adjusting the doping of the P-float and polysilicon layer,respectively,which can suppress the unipolar mode to eliminate the snapback.At turn-off stage,the low-resistance extraction path(N-buffer/P-float/polysilicon layer/N-float)can quickly extract the electrons in the N-drift,which can effectively accelerate the turn-off speed of the device.The simulation results show that at the same Von of 1.3 V,the Eoffof the CBR LIGBT is reduced by 85%,73%,and 59.6%compared with the SSA LIGBT,conventional LIGBT,and TSA LIGBT,respectively.Additionally,at the same Eoffof 1.5 m J/cm2,the CBR LIGBT achieves the lowest Von of 1.1 V compared with the other LIGBTs. 相似文献