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用一维自洽场晶体轨道法探讨了过渡金属夹心高聚物[(C~4BH~5)M]~n(M=Cr,Mn,Fe,Co,Ni)的一维链结构和电子结构.计算表明,堆积单元(C~4BH~5)M中价电子数为奇数的高聚物结构会发生Peierls畸变,而价电子数为偶数的将取规则结构,由能带结构得到, [(C~4BH~5)Mn]~n的前线能带出现交叉,可能会发生进一步的结构畸变,但也有可能保持非满状态,成为异体.[(C~4BH~5)Ni]~n可能是不稳定的.其余三个高聚物为半导体或绝缘体,这系列高聚物电荷载流子通路主要依赖于金属d轨道重叠. 相似文献
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本文采用引入外场微扰的CNDO/S-CI方法, 计算了一系列取代共轭多烯分子的二阶非线性光学系数β~vec, 探讨了 取代基及共轭链长与分子微观非线性光学效应的关系和规律。结构表明:吸电子或供电子基团的引入, 有利于增强分子的微观非线性光学效应, 但该效应随取代基数目增多有减缓的趋势, "饱和"取代时由于"饱和效应"而使β~vec值降低; 取代基间的距离增大, 分子的β~vec值提高, 端基代时β~vec值最大; 取代共轭多烯的lnβ~vec与分子中所含双键数n之间具有线性关系。本文还对上述结论给出了理论解释。 相似文献
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《Quaestiones Mathematicae》2013,36(4):527-530
In this paper, we prove that there exists an infinite dimensional closed vector space M of harmonic functions in R n such that each v ? M \{0} is a universal harmonic function. 相似文献
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Peichu Hu Chungchun Yang 《分析论及其应用》2005,21(2):101-117
In this paper, we will introduce some problems and results between Diophantine approximation and value distribution theory. 相似文献
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《Quaestiones Mathematicae》2013,36(4):539-545
The Padé table of 2 F 1(a, 1; c; z) is normal for c > a > 0 (cf. [4]). For m ≥ n - 1 and c ? Z-, the denominator polynomial Q mn (z) in the [m/n] Padé approximant P mn (z)/Q mn (z) for 2 F 1(a, 1; c; z) and the remainder term Q mn (z)2 F 1(a, 1; c; z)-Pmn (z) were explicitly evaluated by Padé (cf. [2], [6] or [9]). We show that for c > a > 0 and m ≥ n - 1, the poles of Pmn (z)/Qmn (z) lie on the cut (1,∞). We deduce that the sequence of approximants Pmn (z)/Qmn (z) converges to 2 F 1(a, 1; c; z) as m → ∞, n/m → ρ with 0 < ρ ≤ 1, uniformly on compact subsets of the unit disc |z| < 1 for c > a > 0. 相似文献
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On best simultaneous approximation in quotient spaces 总被引:1,自引:1,他引:0
M. Iranmanesh H. Mohebi 《分析论及其应用》2007,23(1):35-49
We assume that X is a normed linear space, W and M are subspaces of X. We develop a theory of best simultaneous approximation in quotient spaces and introduce equivalent assertions between the subspaces W and W + M and the quotient space W/M. 相似文献