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91.
92.
Masaharu Asano Jinhua Chen Yasunari Maekawa Takahiro Sakamura Hitoshi Kubota Masaru Yoshida 《Journal of polymer science. Part A, Polymer chemistry》2007,45(13):2624-2637
A novel process comprising the UV‐induced photografting of styrene into poly(tetrafluoroethylene) (PTFE) films and subsequent sulfonation has been developed for preparing proton‐conducting membranes. Although under UV irradiation the initial radicals were mainly generated on the surface of the PTFE films by the action of photosensitizers such as xanthone and benzoyl peroxide, the graft chains were readily propagated into the PTFE films. The sulfonation of the grafted films was performed in a chlorosulfonic acid solution. Fourier transform infrared and scanning electron microscopy were used to characterize the grafted and sulfonated membranes. With a view to use in fuel cells, the proton conductivity, water uptake, and mechanical properties of the prepared membranes were measured. Even through the degree of grafting was lower than 10%, the proton conductivity in the thickness direction of the newly prepared membranes could reach a value similar to that of a Nafion membrane. In comparison with γ‐ray radiation grafting, UV‐induced photografting is very simple and safe and is less damaging to the membranes because significant degradation of the PTFE main chains can be avoided. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2624–2637, 2007 相似文献
93.
We compare the efficiency of two Faddeev-type approaches for the nuclear three-body Coulomb problem. The first one is a modification
of Noble’s approach, the second one is due to Sasakawa and Sawada. In an integral-equation formulation both of these methods
rely on the same Green’s operators and driving terms. The differences lie in the treatment of the long-range Coulomb potentials.
Numerical examples show that the modified Faddeev-Noble approach provides for faster convergence. 相似文献
94.
J. MALINEN O. NEVANLINNA V. TURUNEN Z. YUAN 《数学学报(英文版)》2007,23(4):745-748
Let T be a bounded linear operator in a Banach space, with σ(T)={1}. In 1983, Esterle-Berkani' s conjecture was proposed for the decay of differences (I - T) T^n as follows: Eitheror lim inf (n→∞(n+1)||(I-T)T^n||≥1/e or T = I. We prove this claim and discuss some of its consequences. 相似文献
95.
Differentiation of functions w.r.t. finite atomless measures with compact support on the real line is introduced. The related harmonic calculus is similar to that of the classical Lebesgue case. As an application we obtain the Weyl exponent for the spectral asymptotics of the Laplacians w.r.t. linear Cantor-type measures with arbitrary weights. 相似文献
96.
本文对近20年来多复变函数的一个发展迅速的数学热门分支-逆紧映照作了一个回顾和整理。这是作者继续从事此方向研究的先声,也希望本文能为有志于此的研究者提供一些便利。本文从经典的结果开始,通过对逆紧映照在边界上的开拓及分支点的分布的讨论,详细地阐述了这些年来关于逆紧映照何时成为双全纯映照的若干结果。最后,对近年来关于逆紧映照另外的一些工作进行了简单的介绍。 相似文献
97.
Dr. Z. Livne 《International Journal of Game Theory》1987,16(3):223-242
The Bargaining Problem paradigm is extended to time-consuming conflict situations. Such a situation can be represented by a chain of bargaining domains, each representing the conflict at a different point in time. The solution function selects a point in the union of all these domains. We characterize a solution function which satisfies several requirements and explore its properties. One of the results is that an extension of the Adding requirement (Thomson-Myerson 1980) is enough, under some conditions, to yield a solution point, so there is no need to extend the stronger requirements of Independence of Irrelevant Alternatives (Nash 1950) or Monotonicity (Kalai-Smorodinsky 1975). 相似文献
98.
The universal condition for the formation of omnidirectional band gaps (OBG) in photonic crystal (PC) was derived with consideration
of permeability of the materials. And it was found that there are four kinds of PCs: one of them has no OBG, and one always
possesses OBG. For the other two kinds of PCs, there are OBG for only TM or TE waves respectively. Moreover, in all PCs, the
OBG can be broadened by decreasing the refractive index of the ambient medium or/and increasing the contrast between the wave
impedances of the component materials of the PC.
PACS 42.70.Qs; 71.20.Tx 相似文献
99.
100.
Perovskite-type lithium fast ion conductors of Li3xLa0.67−xScyTi1−2yNbyO3 system were prepared by solid state reaction. X-Ray powder diffraction shows that perovskite solid solution form in the ranges
of x=0.10, y≤0.10. AC impedance measurements indicate that the bulk conductivities and the total conductivities are of the
order of 10−4 S·cm−1 and 10−5 S·cm−1 at 25 °C respectively. The compositions have low bulk activation energies of about 17 kJ/mol in the temperature ranges of
298 – 523 K and total activation energies of about 37 kJ/mol in the temperature ranges of 298 – 523 K. 相似文献