共查询到17条相似文献,搜索用时 46 毫秒
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介绍了近年来有关外电场对高分子中极化子激子影响的研究工作。它们包括:研究方法,外电场注入的或光激发引起的电子和穴穴会在高分子中形成极化子激子,弱或中等强度电场使极化子激子极化,强电场解离极化子激子,发现高分子中极化子双激子具有反向极化新性质,探讨反向极化这个新的物理现象的物理起因、意义及可能的应用。 相似文献
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高分子的一维特性使电子激发产生显著的自陷(self-trapping)效应,两个单激子(exciton)会复合形成双激子(biexciton),这是形成双激子的重要通道,其效率高于双光子过程.这种复合过程伴随着晶格畸变,需要了解其演变过程并确定其弛豫时间.本文利用动力学方程研究了激子-激子复合的弛豫过程,确定了它的弛豫时间为160fs,同时还研究了外电场E对复合过程的影响,结果表明,当E大于0.5MV/cm时,两个单激子不能复合成双激子,而是解离成正负双极化子.
关键词: 相似文献
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本文引进双激子压缩态,在单激子“非玻色近似”和玻色近似两种情形下,讨论了量子关联和空间关联的双激子的压缩特性、二阶相关特性及其复合辐射光的压缩特性,说明两种情形下双激子玻色近似分别相当于SU(2)群和SU(1,1)群到谐振子群的收缩,并给出这种收缩所带来的结果。
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基于SSH(Su-Schrieffer-Heeger)模型,采用静态及动力学自洽算法模拟了有机高分子链内激子在光激发及外电场作用下的形成与解离过程。结果表明,受光激发后,有机高分子链内激子的生成与解离密切依赖于施加外电场的时机,当外电场与光激发同时发生时,激子能否生成完全取决于电场强度的大小;而当外电场在光激发后的一段时间(通常为皮秒量级)之后被引入,则在有机高分子链内能够形成稳定的激子,且该激子只有在强外电场(超过1MV/cm)的作用下,才会发生解离,临界场强量级与实验结果相符合。 相似文献
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利用Ernst方法,在Harrison变换为线性变换的条件下,得到Kasuya荷电荷磁的外部引力场解,解中所含常量B0表示一均匀弱磁场,该解不要求q=-2B0J.当r趋于∞时,度规接近Melvin’s磁宇宙的渐进行为.该度规是非渐近平直的,在均匀外磁场下这是合理的结果.
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Ernst方法
Kasuya双荷
磁场
引力场 相似文献
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LINEAR ELASTIC RESPONSE OF TUBES TO INTERNAL DETONATION LOADING 总被引:2,自引:0,他引:2
W.M. BELTMANJ.E. SHEPHERD 《Journal of sound and vibration》2002,252(4):617-655
This paper deals with the structural response of a tube to an internal gaseous detonation. An internal detonation produces a pressure load that propagates down the tube. Because the speed of the gaseous detonation can be comparable to the flexural wave group speed, excitation of flexural waves in the tube wall must be considered. Flexural waves can result in much higher strains and stresses than static loading with the same loading pressures. Experiments and numerical simulations were used to determine the structural response. In the experiments, a detonation tube was instrumented with a number of strain gages. A series of experiments was carried out under different conditions. Strains were measured that exceeded the equivalent static strain by up to a factor of 3·9. Special attention was paid to the influence of the detonation speed, reflection and interference of structural waves at flanges and also at the tube end, the linearity of the response, the transient development of the deflection profile, and the influence of detonation cell size. Analytical models and finite element models were used to interpret the observations and to make quantitative predictions of the peak strain. 相似文献