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831.
Phuong-Thanh Dang 《Molecular physics》2013,111(12):1581-1592
Recent work has shown that a certain surface hopping form of the wave function is capable of obtaining highly accurate transition probabilities for nonadiabatic problems. It has also been found that it is necessary to include hops in classically forbidden regions in order to obtain this level of accuracy at low energies. The amplitude for the hops in this surface hopping expansion of the wave function has the typical p?1/2 semiclassical divergence at the turning points in the classical motion. While this singularity is an integrable divergence, the divergent behavior complicates the numerical evaluation of the integrals over hopping points that is present in the surface hopping expressions. Numerical evidence has shown that only small errors are incurred at most energies if these singular hopping amplitudes are replaced with a nonsingular approximation. This agreement is surprising, since the exact and approximate amplitudes differ greatly in the turning point region, and this region is expected to make important contributions to the transition probability at low energies. A numerical analysis is presented in this work that provides a justification as to why this numerically useful approximation works as well as it does. 相似文献
832.
833.
Experimental Verification of Left-Handed Metamaterials Composed of Coplanar Electric and Magnetic Resonators
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We verified experimentally left-handed metamaterials (LHM) composed of coplanar electric and magnetic resonators. A typical LHM sample composed of coplanar resonator unit cells was fabricated, investigated and tested. The experimental results show that the tested sample has a left-handed band of width 1.4 GHz in the X band. The experimental results agree quite well with the simulation ones. Moreover, both the simulation and experimental results show that the LHM under study can automatically achieve good impedance-matching in the left-handed band. 相似文献
834.
采用循环伏安法对合成的硝基吖啶酮(NACR)的电化学行为进行研究,建立硝基吖啶酮差示脉冲伏安法测定核酸的新方法。在pH 4.8的PBS缓冲液中,硝基吖啶酮与ctDNA能够相互作用形成超分子复合物,使硝基吖啶酮在0.043 V处的氧化峰电流下降,峰电流的下降值同ctDNA的浓度在5.0×10-5mg/L~6.5×10-6mg/L范围内呈良好的线性关系,检出限为2.0×10-7mg/L,相关系数为0.9974,已用于实际样品DNA的测定,故硝基吖啶酮有望成为一种新型的生物小分子电化学探针。 相似文献
835.
836.
837.
In this paper,we show that for a locally LEW-embedded 3-connected graph G in orientable surface,the following results hold:1) Each of such embeddings is minimum genus embedding;2) The facial cycles are precisely the induced nonseparating cycles which implies the uniqueness of such embeddings;3) Every overlap graph O(G,C) is a bipartite graph and G has only one C-bridge H such that CUH is nonplanar provided C is a contractible cycle shorter than every noncontractible cycle containing an edge of C.This ext... 相似文献
838.
Qianying Sheng Wenqing Zhang Yan Wang Yi Zhao Haiyan Liu Junhong Qian Bo Zhang Qing Wang Ping Hu 《大学化学》1986,36(1):2002027-0
In order to solve the issues of traditional teaching methods in the undergraduate basic theory course, the blended learning mode was put forward by taking analytical chemistry as an example. With concept of student-centered, personalized teaching, together with assistant means, was introduced to achieve the breakthrough in solving the problems. We hope to reinforce the adaptability and targeting of the course teaching. 相似文献
839.
Jian Ping LI* Qian Fu LUO Yi Yang SHEN Yu Lu WANG Hong WANG College of Chemistry Environmental Science Henan Normal University Xinxiang Department of Chemistry Luoyang Teacher''''s College Luoyang 《中国化学快报》2001,(2)
The subject of organic solid-state synthesis is a fascinating one. It has many advantages such as high efficiency and selectivity, easy separation and purification, mild reaction conditions, and environmental acceptability1. In recent years, this method has been widely used in a variety of organic reactions including substitution2, condensation3, oxidation-reduction4, rearrangement5 and elimination6. However, the solid state reaction using K3Fe(CN)6/KOH to oxidize substituted semicarbazides… 相似文献
840.