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41.
The Degasperis‐Procesi equation can be derived as a member of a one‐parameter family of asymptotic shallow‐water approximations to the Euler equations with the same asymptotic accuracy as that of the Camassa‐Holm equation. In this paper, we study the orbital stability problem of the peaked solitons to the Degasperis‐Procesi equation on the line. By constructing a Lyapunov function, we prove that the shapes of these peakon solitons are stable under small perturbations. © 2007 Wiley Periodicals, Inc. 相似文献
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To determine the stability and instability of a given steady galaxy configuration is one of the fundamental problems in the
Vlasov theory for galaxy dynamics. In this article, we study the stability of isotropic spherical symmetric galaxy models
f
0(E), for which the distribution function f
0 depends on the particle energy E only. In the first part of the article, we derive the first sufficient criterion for linear instability of f
0(E) : f
0(E) is linearly unstable if the second-order operator
has a negative direction, where is the projection onto the function space {g(E, L)}, L being the angular momentum [see the explicit formulae (29) and (28)]. In the second part of the article, we prove that for
the important King model, the corresponding A
0 is positive definite. Such a positivity leads to the nonlinear stability of the King model under all spherically symmetric
perturbations.
An erratum to this article can be found at 相似文献
45.
Xiangang Lin Haiwei Du Daochuan Jiang Peng Zhang Zhiwu Yu Hong Bi Yupeng Yuan 《Journal of Energy Chemistry》2022,(2):541-547
The n-π* electronic transition in polymeric carbon nitride(PCN)can remarkably harvest visible light,which thus potentially promotes the photocatalytic hydrogen H2 generation.However,awaking the n-π* lectronic transition has proven to be a grand challenge.Herein,we reported on the awakening of n-π* electronic transition by microwave thermolysis of urea pellet,which yielded the PCN with absorption edge of 600 nm,near 140 nm red-shift from 460 nm of pristine PCN.The n-π* electronic transition endows PCN with an increased photocata lytic H2 generation,with a highest H2 rate of 61.7μmol h-1 under visible light exposure,which is near 6 times higher than that by using the PCN from the thermolysis of urea pellets in an electric furnace(10.6μmol h-1).Furthermore,the n-π* transition in PCN leads to the longest wavelength of 535 nm that can initiate H2 generation,remarkably longer than the absorption edge of pristine PCN(460 nm).This work manifests the advantages of microwave sintering route to awaken the n-π* electronic transition in PCN for an increased photocata lytic performance. 相似文献
46.
碳元素有多种同素异形体,其稳定性可根据能量判据进行判断。一般认为,石墨是标准状况下碳元素最稳定的同素异形体,其标准摩尔生成焓被定为参考值0k J/mol。近来亦有研究说明金刚石在0K下更稳定。一些文献认为富勒烯比石墨更稳定的说法是错误的,应予纠正。 相似文献
47.
GaAs/GaAlAs定向耦合器型行波调制器:1.设计 总被引:1,自引:0,他引:1
从理论上重点分析和研究了器件行波电极的微波特性,在半绝缘GaAs衬底上设计了具有n^+重掺杂外延层和共平面电极的GaAs/GaAlAs定向耦合器型行波调制器,针对实验中发现的行波电极上微波的高传输损耗问题。分析了起因并提出了器件的改进设计方案,从而设计出可达到35GHz带宽的高速调制效应的光波导调制器。 相似文献
48.
1.3μmDFB半导体激光超短脉冲的产生及其压缩 总被引:2,自引:1,他引:1
本文首次报道1.3μm单模超短脉冲产生及压缩实验。通过梳状波电脉冲直接调制DCPBH-DFB半导体激光器,获得22ps单模光滑脉冲;然后利用G-T干涉仪压缩得到近变换极限超短脉冲。脉宽为9.3ps,峰值功率超过200mW,重复频率1GHz,时间带宽乘积为0.39,脉冲压缩比为2.4。最后对实验结果进行了讨论。 相似文献
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Zhiwu Lin 《Communications in Mathematical Physics》2004,246(1):87-112
We investigate stability and instability of steady ideal plane flows for an arbitrary bounded domain. First, we obtain some general criteria for linear and nonlinear stability. Second, we find a sufficient condition for the existence of a growing mode to the linearized equation. Third, we construct a steady flow which is nonlinearly and linearly stable in the L2 norm of vorticity but linearly unstable in the L2 norm of velocity. 相似文献