排序方式: 共有13条查询结果,搜索用时 62 毫秒
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叠层连续开口圆柱壳的精确解 总被引:2,自引:0,他引:2
抛弃任何有关位移和应力模式的假设,引入δ-函数,对正变异性连续开口圆柱壳建立状态方程.给出薄的、中厚的和强厚的叠层连续开口圆柱壳静力问题的统一的精确解.数值结果和SAPS解进行了对比. 相似文献
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给出了在动应力、动位移和动稳定约束下离散变量结构布局优化设计问题的数学模型,用“拟静力”算法,将具有动应力约束、动位移约束和动稳定约束的离散变量结构布局优化设计问题化为静应力、静位移和静稳定约束的优化问题,然后利用两级优化算法求解该模型.优化过程由两级组成,拓扑级优化和形状级优化.在每一级,都使用了综合算法,并且在搜索过程中都根据两类设计变量的相对差商值进行搜索.对包含稳定约束和不包含稳定约束的优化结果做了比较,结果显示稳定性约束对优化结果产生较大的影响. 相似文献
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集值映射多目标规划问题的解集的连通性 总被引:6,自引:2,他引:4
傅万涛 《高校应用数学学报(A辑)》1994,(3):321-328
本文研究了无限维空间里集值映射的多目标规划问题。主要结果是:当目标函数为类凸的集值映射时,其目标空间里的有效点集是连通的;若目标函数为C-凸的集值映射时,其有效解集也连通。 相似文献
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Blow-UpandMassConcentrationofSolutionsto theCauchyProblemforNonlinearSchrodingerEquations秦玉明Blow-UpandMassConcentrationofSolu... 相似文献
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Ying Li Guang-ping Zhang Zhen Xie Zhao Zhang Jun-feng Ren Chuan-kui Wang Gui-chao Hu 《化学物理学报(中文版)》2016,29(3):344-348
Based on ab initio theory, the interfacial spin polarization of a benzene-dithiolate molecule vertically adsorbed on a nickel surface is investigated by adopting di erent microscopic con-tact con gurations. The results demonstrate a strong dependence of the interfacial spin polarization on the contact con guration, where the sign of spin polarization may vary from positive to negative with the change of contact con guration. By analyzing the projected density of states, an interfacial orbital hybridization between the 3d orbital of the nickel atom and the sp3 hybridized orbital of the sulfur atom is observed. We also simulated the interfacial adsorption in mechanically controllable break junction experiments. The magne-toresistance obtained from Julliere model is about 27% based on the calculated interfacial spin polarization, which is consistent with experimental measurement. 相似文献
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本文在低温条件(∽7 K})下对吸附在Ag(100)表面上的单个空心卟啉分子进行了针尖增强拉曼光谱(TERS)研究. TERS光谱的位置依赖特性表明,单个分子内部不同化学组分的局域振动信息是可以区分的;而且进一步的TERS空间成像也表明不同的拉曼谱峰可以具有不同的空间分布特征,它们与相应的振动模式密切相关,甚至能够在亚纳米层次上识别与卟啉芯N-H键有关的振动模式. 这项研究将为深入理解单分子吸附构型的对称性以及单个分子内部的局域振动信息提供有效的手段. 相似文献
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Atif Ghafoor Ben Yang Yun-jie Yu Yu-fan Zhang Xian-biao Zhang Gong Chen Yao Zhang Yang Zhang Zhen-chao Dong 《化学物理学报(中文版)》2019,32(3):287-291
Single-molecule tip-enhanced Raman spectroscopy (TERS) has emerged as an important technique for structural analysis at sub-molecular scale. Here in this work, we report aTERS study of an isolated free-base porphyrin molecule adsorbed on the Ag(100) surface at cryogenic temperature (∽7 K). Site-dependent TERS spectra reveal distinct local vibrational information for the chemical constituents within a single molecule. Moreover, distinct spatial features among di erent Raman peaks can be resolved from the TERS mapping images. These images are found to associate with related vibrational modes, enabling to resolve the mode associated with N-H bonds at the sub-nanometer level. This study will provide deep insights into the symmetry of adsorption con gurations and local vibrational information within a single molecule. 相似文献