共查询到20条相似文献，搜索用时 62 毫秒
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影响自旋霍尔效应的因素有很多,通过对由平面电场诱导的自旋-轨道耦合对Rashba二维电子气中的本征自旋霍尔效应的影响的研究,表明:当这个由平面电场诱导的自旋-轨道耦合考虑进去之后,在无序的Rash-ba二维电子气中会存在稳定的静态本征自旋霍尔效应.所得到的静态本征自旋霍尔电导呈现出与原先理论设想相符的一些有趣的特征. 相似文献
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在三维柱坐标系下给出了麦克斯韦方程在完全匹配层(PML)吸收边界条件中的时域有限差分(PDTD)表达式，从而把FDTD推广到三维复柱坐标系中并加以实现．为了模拟柱面波在空间的传播，给出了在柱坐标系下完整的总场和散射场的连接边界条件．最后，模拟了柱面波在自由空间中的传播及空心圆柱体在柱面波入射下的近场和远场散射特性． 相似文献
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以自旋为任意整数的粒子的Bargmann-Wigner方程的解为基础。在运动系中直接导出自旋为任意整数的投影算符的表达式，将低自旋投影算符理论推广到了自旋为任意整数的高自旋情形，验证了Behrends和Fronsdal所构造的投影算符的正确性。 相似文献
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在自给平均场理论的框架下，探讨了ＡＦＨｅｉｓｅｎｂｅｒｇ梯子的基态能量和能隙。文中所取的反铁磁体自旋梯子是一个低维系统，该系统由二条Ｓ＝１／２的半整数自旋链相互耦合而成，链与链之间的自旋相互作用为λＪ，链上自旋的相应作用为Ｊ。发现当λｊ＝０时能隙为零，当链间耦合λＪ〉０时有明显的能隙，当λＪ＝１时，能隙△ｈ＝０．５０１，这些结论同许多其它似方法，以及最近的中子散射实验结果相符得很好。 相似文献
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李瑾 《咸阳师范学院学报》2014,29(4)
电磁波束中目标散射场的解析解和数值解是十分重要的,利用Gram-Schmidt方法,从电磁波束传播与极化的角度构建了三维正交归一化的矢量基,得到了任意矢量在Cartesian坐标系中的表达式与新坐标系中的表达式之间的变换,并对该变换的有效性进行了验证,给出了目标位于任意横向电磁波束中散射场的解析式和相应的数值结果;结果在目标电磁相互作用、粒子散射等领域有应用价值. 相似文献
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装箱问题作为一种常见的运筹问题,在很多领域有着重要的应用,装箱问题可以分为一维、二维和三维装箱.主要讨论了二维装箱中条形装箱问题的遗传算法的求解,其中采用后缀表达式的形式对装箱方案进行编码,并详细提出了解码的算法和有关的证明,最后通过实例证明了该算法是可行的. 相似文献
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李国锋 《赣南师范学院学报》2009,30(3):52-54
研究一束自旋极化电子在准一维系统中的榆运,输运电子经过一个势阱和SOI共同作用的散射区．研究发现经过散射后电子自旋翻转的概率与费米能廓、势阱的深度Vo、自旋轨道耦合的强度λR以及各通道的能级Ej,并且翻转概率具有周期振荡特性,即随散射区的长度呈周期性变化． 相似文献
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以二维弹性力学问题为研究对象，采用常单元和线性非连续元离散边界积分方程，给出系数矩阵计算的精确表达式。数值实施证实此方法的准确性。和有限元相比，边界元的目的非常明确。它还使数值计算的维数降低一阶，所以计算效率也更高。 相似文献
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朱云生 《广东民族学院学报》1993,(4):5-17
本文在Biot理论的基础上系统讨论了固液二相介质中的动力学关系，对介质系统涉及到的质量耦合系数，弹性常数、粘耦合系数及波动方程都作了必要的数学推导，进而针对被孔隙地层包围且充满液体的柱状井眼，建立起声测井理论模型，具体给出了由井轴上一点声源激发的井内声场波函数解和场点的声压表达式。最后应用离散波函数技术在计算机上实现了声测井全波合成，并就地层渗透率对低频斯通利波衰减影响作了初步分析。 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 相似文献
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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 相似文献