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51.
52.
A new cadmium complex [Cd(C5H5N)CH2C(OH)(PO3)(PO3H)·3H2O]n((C5H4N)CH2C(OH)(PO3H2)2=1-hydroxy-2-(2-pyridyl)ethylidene-1,1-diphosphonate acid) has been synthesized under hydrothermal conditions. Single crystal structure determination reveals that the compound has a ladder-like chain structure in which the edge-shared {CdO6} octahedra are linked by {CPO3} tetrahedra through corner-sharing. The chains of {Cd(C5H5N)CH2C(OH)(PO3)(PO3H)}n are linked by inter-chain hydrogen bonds, forming a supramolecular layer. CCDC: 722396. 相似文献
53.
We investigate theoretically the electronic transport through a parallel-coupled double quantum dot (DQD) molecule attached to metallic electrodes, in which the spin-flip scattering on each quantum dot is considered. Special attention is paid to the effects of the intradot spin-flip processes on the linear conductance by using the equation of motion approach for Green’s functions. When a weak spin-flip scattering on each quantum dot is present, the single Fano peak splits into two Fano peaks, and the Breit–Wigner resonance may be suppressed slightly. When the spin-flip scattering strength on each quantum dot becomes strong, the linear conductance spectrum consists of two Breit–Wigner peaks and two Fano peaks due to the quantum interference effects. The positions and shapes of these resonant peaks can be controlled by using the magnetic flux through the quantum device. 相似文献
54.
特征标次数的重数与可解群结构 总被引:1,自引:1,他引:1
非线性不可约特征标次数的重数全部为1的有限群的分类是熟知的.对可解群,本文讨论更一般的,即非线性不可约特征标次数的重数都与群阶互素的有限群的纯群论性质.特别地,得到了非线性不可约特征标次数的重数均小于2p的奇阶群G的分类结果.这里p为群阶|G|的最小素因子. 相似文献
55.
Kernel density estimators (KDE) used for many medical image applications only consider the intensity information of each pixel or its neighbors without the ability of expressing the structure and shape of tissues and organs, and they suffer from boundary bias problem. In this paper, we propose a new first-order kernel density estimation (FOKDE) method for 1D intensity information and 2D spatial information of medical image in two steps. First, the FOKDE of intensity information is estimated and applied to medical image segmentation with the multi-thresholding algorithm. Second, we estimate the FOKDE of spatial information on the initial segmentation, which can express the structure and shape of organs and tissues. In order to evaluate the FOKDE and KDE of the 2D spatial information, we apply them to medical image segmentation with the hill-climbing strategy. Density estimation experiments and segmentation application results on the simulated dataset and real abdomen CT images show us that the FOKDE has smaller boundary bias than the KDE, and that it can estimate the structure and shape of tissues and organs with spatial information effectively. 相似文献
56.
Liu Longfei Ni Lei Yang Jie Jiang Juncheng Yang Gaowen 《Journal of Thermal Analysis and Calorimetry》2018,132(3):1763-1770
Journal of Thermal Analysis and Calorimetry - A novel multicyclo-tetrazoles energetic material, 1,3,3,5-tetra(1H-tetrazol-5-yl)-pentane (TTZP), was prepared by 1,3,3,5-tetra(cyano)-pentane and... 相似文献
57.
用分子动力学模拟方法,计算了氟代硼酸锂玻璃的电导率.研究的温度范围高于和近于玻璃转变温度,共模拟了七个体系,研究的成分大致覆盖了能形成玻璃的区域.所得极限电导率、活化能以及电导率随温度的变化与实验数据符合得相当好.以往的研究认为快离子传导的典型特征是仅有一种离子发生迁移,我们的模拟表明氟离子对电导也有较大贡献.用活化能数据可顺利解释这个三元系各体系的电导率相对高低问题. 相似文献
58.
用量子化学半经验方法和从头算对二苯并四氮杂[14]轮烯(Tmtaa)离子及其金属配合物的电子结构进行了详细的研究.讨论了轮烯金属配合物合成的模板效应及金属离子半径大小对模板效应的影响作用,对其亲电取代反应的活性位置作了相应理论解释.依据理论计算结果指导了轮烯配合物的定向亲电取代反应及新金属配合物的合成尝试,理论计算与实验事实基本一致.Tmtaa-Ni等配合物及其亲电取代反应产物的1HNMR谱、19FNMR谱表明金属配合物中金属离子对位C7、C16上的H原子被取代,与理论计算结果十分一致. 相似文献
59.
In this paper, the concept of equimodular is introduced. It contains several generalizations of Mazur-Ulam's isometric theorem in modular spaces. Let X and Y be two real modular spaces and X with δ1-midpoint shrinking whose modular ρX satisfies the Δ2-condition. Assume that an operator T maps X onto Y in an δ2-{ti}-equimodular manner for all , where {ti} is a null-sequence of nonnegative reals with the property that t0=1, t1?1/2, and ti?ti−1?2ti for i?2. Then T is affine. 相似文献
60.
On automorphism groups of some finite groups 总被引:1,自引:0,他引:1
钱国华 《中国科学A辑(英文版)》2003,46(4):450-458
We show that if n > 1 is odd and has no divisor p4 for any prime p, then there is no finite group G such that│Aut(G)│ = n. 相似文献