排序方式: 共有39条查询结果,搜索用时 0 毫秒
11.
采用矢量分析方法,我们建立了电磁介质极化和磁化的一般理论,恰当地定义了可以描述任意束缚电荷和束缚电流分布的极化强度矢量和磁化强度矢量.无需借助电偶极子模型和分子环流模型,仍然可以推导束缚电荷和束缚电流分布与极化强度矢量和磁化强度矢量的定量关系.在宏观电磁理论中,分子环流模型和磁偶极子模型具有同等的地位,它们都可以诠释自旋磁矩的磁效应. 相似文献
12.
13.
14.
16.
Based on the scattering matrix approach.we systematically investigate the anharmonic effect of the pumped current in double-barrier strructures with adiabatic time-modulation of two sinusoidal AC driven potential heights. The pumped currem as a functionof the pha.se difference bet ween the two driven potentials looks like to be sinusoidal, but actually it contains sine functions of double and more phase difference, it is found that this kind of anharmonic effect of the pumped current is determined combinedly by the Berry curvature and parameter va.riation loop trajectory. Therefore small ratio of the driving amplitude and the static amplitude is not necessary for harmonic pattern in the pmnped era'rent, to dominate for smooth Berry curvatureon the surface within the parameter variation loop. 相似文献
17.
18.
电磁感应的通量法则是一条在电路近似下成立的经验规律。结合电磁场的观念,可以得到麦克斯韦方程组中法拉第电磁感应定律的积分和微分形式;它是比通量法则更为基本的电磁规律。考虑电磁规律的相对论不变性,本文修正了电动势的定义和计算公式,并得到通量法则的“低速小尺寸”极限。 相似文献
19.
20.
We investigate the period halving of persistent currents (PCs) of non-interacting electrons in isolated mesoscopic Mobius ladders without disorder,pierced by Aharonov-Bohm flux.The mechanisms of the period halving effect depend on the parity of the number of electrons as well as on the interchain hopping.Although the data of PCs in mesoscopic systems are sample specific,some simple rules are found in the canonical ensemble average,for example,all the odd harmonics of the PCs disappear and the signals of even harmonics are non-negative. 相似文献