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991.
M. Klingler  W. F. Chu  W. Weppner 《Ionics》1995,1(3):251-256
Electrochromic effects are observed by employing a single mixed ionic and electronic conducting layer in-between two transparent electronic leads. Besides the simplicity of the arrangement, the advantage is the displacement of ions only within one phase rather than across phase boundaries as required by conventional devices. The applied voltage controls the compositions at the two interfaces according to Nernst's law independent of ions being majority or minority charge carriers. Appropriate materials are intrinsic conductors in the unpolarized transparent state which become n-type and p-type conducting at the negative and positive electrode side, respectively. Several materials have been investigated, such as lithiated tungsten oxide and lithium/tantalum co-doped tungsten oxide. Paper presented at the 1st Euroconference on Solid State Ionics, Zakynthos, Greece, 11–18 September 1994.  相似文献   
992.
We report polarized photon correlation measurements of bulk poly(phenylmethyl siloxane) (PPMS) with a molecular weight of about 2500 at different pressures from 1 to 1750 bar and temperatures between 269 and 308 K. In the Frequency range accessible by present-day digital correlators, the time correlation function can measure a slow q2-dependent diffusional process due to local concentration fluctuations and a fast α-mode structural relaxation process. The mean characteristic times of the two processes approach each other at low temperatures and high pressures, in contrast to the behavior of the α- and β-relaxation times. We should be cautious in relating the mean characteristic times for the structural relaxation process obtained by different experimental techniques, such as Brillouin scattering and photon correlation spectroscopy, because of the differnces in the probe emphasis and the extremely broad frequency distribution of such relaxation processes.  相似文献   
993.
994.
推广了RVUU模型,计入了K介子的平均场势和K与核子的末态重散射.并用它模拟了每核子1GeV入射能量的两个Ca核碰撞的阈下K+产生.讨论了K+矢量势和K+末态重散射效应对K介子的末态性质的影响.计算结果表明,排斥的矢量势,与K+的末态重散射相似,明显地影响了末态K+动能谱,导致了实验室系中具有大动量的K+产额的增大.然而,排斥的K+矢量势的计入可观地减少了K+的末态重散射的影响.这说明,为了合理地评价K+能谱和角分布,K+同核子的这些末态作用都是不能忽略的.  相似文献   
995.
The X-ray crystal structure of 5-methyl-5,10-dihydrophenarsazine, C13H12NAs, has been determined. The crystals are orthorhombic, space group P212121, a = 8.511(4), b = 5.690(1), c = 23.535(9) Å, V = 1139.7(1.0)A3, and Z = 4. Least-squares refinement converged to R = 0.049 and Rw = 0.045. The central ring is in a boat conformation and the 5-methyl group is in the axial position with respect to the central ring. The folding angle between the planes of the two benzo rings is 154.1(4)°.  相似文献   
996.
It is shown that many of the existing index profiling methods for optical fibre and preform are related to one another through the deflection function from which the index profile is reconstructed. These methods are classified into direct deflection function measurement, integral (or phase) measurement, and differential (or intensity) measurement. The deflection function from the integral method is obtained by measuring the phase distribution of the exit rays followed by numerical differentiation. Thus the reconstructed index profile has Gaussian noise. The deflection function from the differential method is obtained by measuring the light intensity distribution followed by a numerical integration. This process enhances low frequency noise but suppresses high frequency noise. The noise from direct method behaves in the similar manner as in the differential method except that it is less pronounced. Studies of the choice of methods for profiling of preform, multimode fibre and single mode fibre are also given.  相似文献   
997.
998.
999.
本文提出了入射光面转动的新型工作模式TeO2声光偏转器,入射光面转动K波矢位在(11)平面,(110)平面是(110)-(001)面绕(11)轴转动一定角度而得,这种器件的特点是,比通常的偏转器具有最高的衍射效率和更宽的动态范围。  相似文献   
1000.
M. Klingler  W. F. Chu  W. Weppner 《Ionics》1997,3(5-6):412-419
The transport properties of ionic conductors such as α-AgI and Li0.23La0.69Fe0.3Ti0.7O3 and of electronically conducting semiconductors such as α-Ag2S and AgxWO3 as a result of the application of voltages smaller than the decomposition voltage by two ionically blocking electrodes were investigated. The mobile ionic as well as the mobile electronic species are shifted from one electrode side to the other one. The change in the stoichiometric composition within the sample as a result of this transport process causes the formation of local inhomogeneities leading to changes in the electrical and optical properties. The experimental results also show that Nernst's law is not only valid for ionic conductors but also for semiconductors as well when a steady state is reached for ionically blocking electrodes. Paper presented at the 4th Euroconference on Solid State Ionics, Renvyle, Galway, Ireland, Sept. 13–19, 1997  相似文献   
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