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51.
Yunsheng Ding Haiou Tang Xiaomin Zhang Shuying Wu Renyan Xiong 《European Polymer Journal》2008,44(4):1247-1251
In this study, 1-n-tetradecyl-3-methylimidazolium bromide ([C14mim]Br), one kind of imidazolium ionic liquid (imi-IL), was incorporated into polypropylene (PP) via melt blending. The measurement of surface resistance (Rs) and volume resistance (Rv) of neat PP and PP/[C14mim]Br blends indicated that [C14mim]Br had excellent antistatic properties. The PP/[C14mim]Br blend had the best antistatic ability, when the weight ratio of [C14mim]Br to PP reached 3/100. The surface resistance of PP/[C14mim]Br decreased from the 7.67 × 1013 to 1.40 × 107 Ω whereas the volume resistance of PP decreased from 2.67 × 1014 to 2.60 × 107 Ω. Semicrystalline morphology and crystal structure were investigated by polarized optical microscopy (POM) and X-ray diffraction (XRD). The spherulites of PP became smaller with the addition of [C14mim]Br, implying that [C14mim]Br had a nucleating effect in the PP matrix. The XRD study indicates the crystallization process of PP was affected by [C14mim]Br, and the crystallinity of PP was thus decreased. Scanning electron microscopy (SEM) studies reveal that [C14mim]Br had good dispersion in PP; thermogravimetric analysis (TGA) shows the addition of [C14mim]Br remarkably increased the thermal stability of PP even though it is a small molecule. 相似文献
52.
Summary A molecular dynamics/energy-minimisation protocol has been used to analyse the structural and energetic effects of functional group substitution on the binding of a series of C4-modified 2-deoxy-2,3-didehydro-N-acetylneuraminic acid inhibitors to influenza virus sialidase. Based on the crystal structure of sialidase, a conformational searching protocol, incorporating multiple randomisation steps in a molecular dynamics simulation was used to generate a range of minimum-energy structures. The calculations were useful for predicting the number, location, and orientation of structural water molecules within protein-ligand complexes. Relative binding energies were calculated for the series of complexes using several empirical molecular modelling approaches. Energies were computed using molecular-mechanics-derived interactions as the sum of pairwise atomic nonbonded energies, and in a more rigorous manner including solvation effects as the change in total electrostatic energy of complexation, using a continuum-electrostatics (CE) approach. The CE approach exhibited the superior correlation with observed affinities. Both methods showed definite trends in observed and calculated binding affinities; in both cases inhibitors with a positively charged C4 substituent formed the tightest binding to the enzyme, as observed experimentally.This paper is based on a presentation given at the 14th Molecular Graphics and Modelling Society Conference, held in Cairns, Australia, August 27–September 1, 1995.Presently on a visiting postdoctoral fellowship in the Department of Biomolecular Structure, Glaxo Research & Development Ltd, Greenford, Middlesex UB6 OHE, U.K. 相似文献
53.
Masahiro Manabe Toshihiro Ochi Hideo Kawamura Hajime Katsu-ura Masaki Shiomi Mandeep Singh Bakshi 《Colloid and polymer science》2005,283(7):738-746
The partial molar volumes (Va) of 1-alkanols (carbon number, m=5, 6, 7) in - and -cyclodextrin (CD) solutions at 5.00 mmol kg–1 have been determined as a function of alkanol concentration (Ca) between 293.2 and 308.2 K by using a dilatometer. It has been observed that with an increase in Ca, Va increased in -CD solution but decreased in -CD solution, asymptotically to a value of Va in CD-free water. The dependence of Va on Ca provided the binding constant (K) of 1:1 complex, the volume change in complex formation, and the partial molar volume of complex itself. The complex formation mechanism has been discussed on the basis of these values and their carbon number dependences in the respect of geometric behavior, hydrophobic interaction, and van der Waals interaction. It is concluded that the CD cavity in water is not rigid but flexible for fitting in nicely with guest molecule. 相似文献
54.
晶体学研究曾认为分子式是NaNiQ2HQCLO4的结构并不含有钠而应为H3ONiQCLO4.相似地,稀土-Ni络合物YQHQ2NiQ3CLO4也不含有钇而应为H3ONi2Q3CLO4.晶体结构描述的修正系根据文献报导的原子坐标计算结构因子所导出的结果. 相似文献
55.
Xinzheng Zhang Jingjun Xu Qian Sun Simin Liu Guoquan Zhang Haijun Qiao Feifei Li Guangyin Zhang 《Optics Communications》2000,180(4-6):211-215
A simple, convenient and effective way is demonstrated to reduce the field losses of the reconstructed image in the dual-wavelength nonvolatile holographic storage by adding a cylindrical lens in the holographic recording configuration. The experimental results show that this technique makes the dual-wavelength nonvolatile holographic storage compact and practical. 相似文献
56.
We first prove a quantitative estimate of the volume of the sublevel sets of a plurisubharmonic function in a hyperconvex domain with boundary values 0 (in a quite general sense) in terms of its Monge–Ampère mass in the domain. Then we deduce a sharp sufficient condition on the Monge–Ampère mass of such a plurisubharmonic function φ for exp(−2φ) to be globally integrable as well as locally integrable. 相似文献
57.
O. Briant C. Lemaréchal Ph. Meurdesoif S. Michel N. Perrot F. Vanderbeck 《Mathematical Programming》2008,113(2):299-344
When a column generation approach is applied to decomposable mixed integer programming problems, it is standard to formulate
and solve the master problem as a linear program. Seen in the dual space, this results in the algorithm known in the nonlinear
programming community as the cutting-plane algorithm of Kelley and Cheney-Goldstein. However, more stable methods with better
theoretical convergence rates are known and have been used as alternatives to this standard. One of them is the bundle method;
our aim is to illustrate its differences with Kelley’s method. In the process we review alternative stabilization techniques
used in column generation, comparing them from both primal and dual points of view. Numerical comparisons are presented for
five applications: cutting stock (which includes bin packing), vertex coloring, capacitated vehicle routing, multi-item lot
sizing, and traveling salesman. We also give a sketchy comparison with the volume algorithm.
This research has been supported by Inria New Investigation Grant “Convex Optimization and Dantzig-Wolfe Decomposition”. 相似文献
58.
J.D. Schwarzkopf C.T. Crowe J.J. Riley S. Wetchagarun P. Dutta 《International Journal of Multiphase Flow》2009
This study focuses on understanding how the presence of particles, in homogeneous turbulence decay, affects the dissipation of dissipation coefficient within the volume averaged dissipation transport equation. In developing this equation, the coefficient for dissipation of dissipation was assumed to be the sum of the single phase coefficient and an additional coefficient that is related to the effects of the dispersed phase. Direct numerical simulation was used to isolate the effect of stationary particles in homogeneous turbulent decay at low Reynolds numbers (ReL = 3.3 and 12.5). The particles were positioned at each grid point and modeled as point forces and a comparison was made between a 643 and 1283 domain. The results show that the dissipation of dissipation coefficient correlates well with a dimensionless parameter called the momentum coupling factor. 相似文献
59.
郑俊博 《西安联合大学学报》2000,3(2):58-61
用普通物理学的方法推导了不同惯性系之间产场量的变换式,在此基础上,给出了一咱简便、快捷并且物理意义清晰的建立麦克斯韦方程组的新途径。 相似文献
60.
介绍了当前交国刨花板生产中测定胶液流量的三种主要方法,分析比较了这三种方法的工作原理和工作特点,最后进行了总结并提出了建议。 相似文献