Computing Orbits of the Automorphism Group of the Subsequence Poset B m,n

Let B _m,n denote the set of all words obtained from the cyclic word of length n on an alphabet of m letters in by deleting on all possible ways and their natural order. In [Order, 16: 179–194, 1999] Burosch et al. computed the automorphism group of the poset B _m,n . In this paper, we apply this result to obtain all of orbits of the natural action of Aut(B _m,n ) on B _m,n .     

Determination of the g-factor of n-type HgTe/Hg1−xCdxTe single quantum wells

The effective g-factor of modulation doped n-type HgTe single quantum wells, SQWs, has been determined by the coincidence method in tilted magnetic fields to lie between 15 and 35. For symmetrically doped samples the effective g-factor has been found to be constant for different filling factors; however, for asymmetric SQWs, a large increase with increasing filling factor has been observed. This can be ascribed to a combination of Zeeman spin splitting and Rashba spin–orbit splitting. Reasonable agreement has been achieved between theoretical calculations based on the 8×8 k · p method and experimental results.     

模糊子群的阶的注记

讨论一个群G的模糊子群μ的阶与μ所对应的子群链之间的关系和具有有限生成元的阿贝尔群的阶与其模糊子群的阶的关系，并得到了一些相关结果。     

ON CLOSED ORBIT FOR A CLASS OF PLANAR SYSTEMS OF HIGH DEGREE

1.IntroductionThepolynomialdifferentialequationofdegreep qwherep2l,q21areintegersandx20,y20,a>0arerealnumber,asknownin[12],describesthedynamicalbehaviorsofmulti-molecularbiochemicalreactionHerex,yandp,qdenoterespectivelytheconcentrationsofsubstancesandnumbersofmolecules.UsuallyEq.(1.1)iscalled"TI-moleculesmodel"withn~p q.LikePrigogine'sB.....l.t.rI4],Higgins'm.del[5]andTyson-Lighe'smodel[6],itisofsignificanceinourunderstandingofthephenomenaofnonequilibriumstates[3].Thecaseofn=3isdiscussedp…     

BEPCⅡ-Linac束流光学和轨道校正的优化研究

为实现BEPCⅡ的总体要求,对直线注入器的强流电子束和正电子束进行了系统的束流光学模拟和优化研究.提出了束流光学的自动校正环路.系统地研究了束流初始偏轴和加速器部件的安装误差对束流归一化发射度和轨道偏移的影响.提出了采用“一对一”的束流轨道校正机制,以有效抑制这些影响,确保直线注入器的束流性能.     

同宿流形中的奇异轨道

研究较一般的高维退化系统的同宿、异宿轨道分支问题．利用推广的Melnikov函数、横截性理论及奇摄动理论，对具有鞍—中心型奇点的带有角变量的奇摄动系统，在角变量频率产生共振的情况下，讨论其同宿、异缩轨道的扰动下保存和横截的条件．推广和改进了一些文献的结果。     

Absorption and Recurrence Spectra of Sodium Rydberg Atom in a Strong External Magnetic Field

Using core-scattered closed-orbit theory, we calculate the photoabsorption and the scaled recurrence spectra of sodium Rydberg atom in strong magnetic field below ionization threshold. The non-Coulombic nature of the ionic core have been modified by a model potential, which includes an attractive Coulomb potential and a short-ranged core potential. A family of core-scattered nonhydrogenic closed orbits have also been discovered. The Fourier transformed spectra of sodium atom have allowed direct comparison between peaks in such plot and the scaled action values of closed orbits. The new peaks in the recurrence spectra of sodium atom have been considered as effects caused by the core scattering of returning waves at the ionic core. The results are compared with those of hydrogen case, which show that the core-scattered effects play an important role in alkali-metal atoms.     

关于奇阶群的大轨道

设H和G是有限群。G忠实作用在H上且(|G|，|H|)=1，I．M．lsaacs曾经提出一个问题：G在H上是否有大轨道?本文证明了：这一问题完全可以简化成H是不可约忠实G模的情形，进一步，利用这一结论和已知的结果我们证明了：当|G|和|H|是奇数时，lsaacs问题是肯定的。     

Possible polaron formation of zigzag graphene nano-ribbon in the presence of Rashba spin–orbit coupling

In this article we study the role of Rashba spin–orbit coupling and electron–phonon interaction on the electronic structure of zigzag graphene nanoribbon with different width. The total Hamiltonian of nanoribbon is written in the tight binding form and the electron–electron interaction is modeled in the Hubbard term. We used a unitary transformation to reach an effective Hamiltonian for nano ribbon in the presence of electron–phonon interaction. Our results show that small Rashba spin orbit coupling annihilates the anti-ferromagnetic phase in the zigzag edges of ribbon and the electron–phonon interaction yields small polaron formation in graphene nano ribbon. Furthermore, Rashba type spin–orbit coupling increases (decreases) the polaron formation energy for up (down) spin state.     

Angular dependent study on spin transport in magnetic semiconductor heterostructures with Dresselhaus spin–orbit interaction

We investigate theoretically the effects of Dresselhaus spin–orbit coupling (DSOC) on the spin-dependent current and shot noise through II–VI diluted magnetic semiconductor/nonmagnetic semiconductor (DMS/NMS) barrier structures. The calculation of transmission probability is based on an effective mass quantum-mechanical approach in the presence of an external magnetic field applied along the growth direction of the junction and also applied voltage. We also study the dependence of spin-dependent properties on external magnetic field and relative angle between the magnetizations of two DMS layers in CdTe/CdMnTe heterostructures by including the DSOC effect. The results show that the DSOC has great different influence on transport properties of electrons with spin up and spin down in the considered system and this aspect may be utilized in designing new spintronics devices.