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Further results on ultraconvergence derivative recovery for odd-order rectangular finite elements 总被引:1,自引:0,他引:1
For rectangular finite element, we give a superconvergence method by SPR technique based on the generalization of a new ultraconvergence
record and the sharp Green function estimates, by which we prove that the derivative has ultra-convergence of order O(h
k+3) (k ⩾ 3 being odd) and displacement has order of O(h
k+4) (k ⩾ 4 being even) at the locally symmetry points.
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An effective Hamiltonian of the two-dimensional antiferromagnetic Heisenberg model is derived by using the Holstein-Primakoff transformation. Three nonlinear coupled partial equations of motion are obtained. In the long-wavelength approximation, these equations, are reduced to the envelope function equations by the method of multiple scales. The amplitude functions satisfy the nonlinear Schrodinger equation. Introducing an inverse scatteriag transformation, the single-, two- and multi-soliton solutions in the two-dimensional antiferromagnetic Heisenberg model are investigated. 相似文献
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QIN DaShan LI GuiFang QUAN Wei CHEN Lei LIU JinSuo ZHANG JiDong YAN DongHang 《中国科学:物理学 力学 天文学(英文版)》2013,(3):530-534
The ternary blend films have been fabricated via adding 4,4’-N,N’-dicarbazole-biphenyl(CBP,a hole transport material widely used in organic light emitting diodes) into the poly(3-hexylthiophene):[6,6]-phenyl C 61-butyric acid methyl ester(P3HT:PCBM).Despite the wide bandgap(3.1 eV) of the CBP,the solar cell utilizing the optimized P3HT:PCBM:CBP blend film showed an increase of 16% in power conversion efficiency and 25% in short-circuit current than the compared standard P3HT:PCBM blend film.This is attributed to the fact that the addition of the CBP could enhance the aggregation of the P3HT chains and thereby reduce the hole-electron recombination at the interface of P3HT and PCBM.We provide a simple,effective way to improve the performance of P3HT based bulk heterojunction solar cells. 相似文献
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Bai JingSong Tang Mi Luo GuoQiang Yu JiDong Yuan Shuai Dai ChengDa Wu Qiang Tan Hua 《中国科学:物理学 力学 天文学(英文版)》2011,54(9):1710-1716
Two types of Mg-Cu composition system graded density impactors used for complex loading (shock loading and quasi-isentropic compression) are designed by the elastic-plastic hydrodynamic method in this paper. Mixtures of metal powders in the Mg-Cu system are cast into a series of 17 and 25 uniform compositions ranging from 100% Mg to 100% Cu. The graded density impactors are launched to the stationary 10 m aluminum film and 12 mm LiF window targets by a two-stage light-gas gun in the National Key Laboratory ... 相似文献
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本文研究对角占优矩阵奇异-非奇异的充分必要条件.基于Taussky定理,本文得出,可约对角占优矩阵的奇异性由其独立Frobenius块的奇异性决定,从而将这一问题化为不可约对角占优矩阵的奇异-非奇异性问题;运用Taussky定理研究奇异不可约对角占优矩阵的相似性和酉相似性,获得这类矩阵元素辐角间的关系;并与Taussky定理给出的这类矩阵元素模之间的关系结合在一起,研究不可约对角占优矩阵奇异的充分必要条件;最后给出不可约对角占优矩阵奇异-非奇异性的判定方法. 相似文献
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