An analysis of the electrical conductivity in BaSO4-added Ag2SO4 solid electrolyte system

The compositions (1 −x)Ag₂SO₄−(x)BaSO₄, wherex=0·01 to 0·6, were prepared by slow cooling of the melt. The extent of the solid solubility of Ba²⁺ in Ag₂SO₄ was determined by X-ray powder diffraction and scanning electron microscopy. The bulk conductivity of each sample was obtained using a detailed impedance analysis. The partial substitution of Ba²⁺ results in the enhancement of conductivity in compliance with the classical aliovalent doping theory. A simplistic model based on lattice distortion (expansion) due to partial substitution of Ag⁺ by the bigger Ba²⁺ has been considered to explain enhanced conductivity. Beyond solid-solubility limit (5·27 mole%) the BaSO₄-dispersed Ag₂SO₄ conductivity follows the usual trend seen in binary systems. An increase in conductivity in this case is discussed in the light of interfacial reactions and surface defect chemistry. The maximum conductivity in 20 mole% BaSO₄ dispersed Ag₂SO₄ is due to percolation threshold.     

四维空间直线绕平面的旋转

本文对四维空间直线绕平面旋转的轨迹进行一投详尽的讨论，按照直线与“轴平面”的相对位置不同，该旋转轨迹分别为圆柱面、圆锥面和单叶回转双曲面，并认为这些回转曲面的轴线是过该直线的与“轴平面”垂直的超平面与“轴平面”的交线。     

Gloss Properties and Surface Morphology Relationships of Fruits

Eggplants exhibited a higher average gloss reading (15.3 Gloss Units (GU)) than mature green tomatoes (12.0 GU) and apples (8.2 GU) using a flat surface glossmeter. The same trend was observed using a novel curved surface glossmeter. Scanning electron micrographs revealed that epicuticular wax covering eggplants had a smoother structure than that of tomatoes and apples, providing a more effective light scattering surface. Wax removal resulted in decreases in gloss, with average readings of 9.5, 7.4 and 6.3 GU for eggplants, tomatoes and apples, respectively. These results indicate the extent to which wax may influence shininess, although roughness measurements of flattened peel after wax removal suggest that surface topography also influences gloss.     

新型蓝绿发光材料ZnSe／BeTe超晶格的能带剪裁

由于器件的快速退化，101.5小时似乎成了Znse基蓝绿色半导体激光器难于逾越的寿命极限。分析退化机制，发现在强电流注入的半导体激光器中，热退化具有重要影响。研究表明，用作载流子限制层的宽带Ⅱ-Ⅵ族四元合金（如ZnMgSSe）只能对ZnSe中的电子有效地限制，无法对空穴很好地限制;而对BeTe，却只能对空穴进行有效的限制，无法对电子很好地限制。这导致ZnSe（或BeTe）活性层空穴（或电子）漏电发热，引起退化。本文提出以ZnSe／BeTe超晶格为蓝绿发光层，并用包络函数理论具体计算了阱宽、垒宽对载流子能级的不同影响，考察了ZnSe、BeTe厚度比和超晶格周期对带隙、载流子限制能力的调节。为研制新型长寿命蓝绿色半导体激光器提供了一条新的途径。     

Effect of Forming Pressure on the Internal Structure of Alumina Green Bodies Examined with Immersion Liquid Technique

Green bodies prepared by compaction of alumina granules were made transparent by an immersion liquid technique, and the internal structure was characterized with an optical microscope to study the effect of forming pressure on the internal structure. Clear images obtained by the technique provide more detailed information than other existing methods for structures ranging from one to tens of micrometers. Intergranular pores were present between unfractured granules. Their sizes and concentration tended to decrease with increasing forming pressure. However, pores were clearly present even in the green body prepared at 600 MPa. A rod- and needlelike feature was also found and was concluded to correspond to a high-density region. The significance of large pores and high-density regions on processing as well as the details of the technique is discussed.     

认真创建服务型企业拓展老水电厂发展空间——湖北省白莲河水力发电厂发展问题的思考

根据对白莲河电厂历史的与现状的分析,提出该厂应当由生产型向服务型转变,在服务中提高职工素质,拓展老水电厂的发展空间.     

鄂尔多斯西缘前陆盆地巨厚黄土地区地震采集技术

鄂尔多斯西缘前陆盆地表层地质地貌极其复杂，有巨厚黄土区、黄土-沙漠区及山前砾石-黄土区，独特的黄土地貌使得地震采集面临着诸多技术难题。根据以往巨厚黄土地区地震采集经验，采用多种方法系统地开展黄土表层结构精细调查，深入研究黄土地球物理特征及激发因素与表层黄土结构之间的关系，优选激发井位和井深，确保了激发效果；采用小道距、三线小线距、高密度空间采样技术，获得了高信噪比、高分辨率地震资料。研究表明，巨厚黄土地区地震采集时应优选激发井位和岩性，合理选择激发井深；坚持多深井组合激发、单井药量不宜过大总药量要大两项基本原则；采用高密度采样技术，提高采集资料的覆盖次数和信噪比。图10表1参15     

Lateral space-charge effects on ballistic electron transport across graded heterojunctions

Hot electron transport across graded compound semiconductor heterojunctions has been explored using a two-dimensional formulation of the self-consistent ensemble Monte Carlo method. The Al_xGa_1-xAs/GaAs heterojunction imbedded into a vertical field effect transistor with two ohmic contacts (source, drain) and two lateral Schottky gates has been used as an example. Lateral space charges modulated by the gates are shown to control ballistic injection of electrons over the heterojunction under steady state conditions. The transient response to a gate pulse is found to be determined by carrier transit from the heavily doped source contact region into the channel. A conceptual one-dimensional section model is used to explain the Monte Carlo results.     

自干扰抵消盲空时DS-CDMA信号检测技术

针对传统单用户检测器存在远近效应和性能下界问题,近年来提出的一系列最大SINR准则盲空时RAKE接收机,可以较好地合并期望用户的多径分量,同时抑制多址干扰用户能量.本文对这类接收机进行了进一步的研究,提出了一种自干扰抵消方法,更有效地克服了单用户检测器存在的性能下界以及远近效应问题.仿真结果验证了本文方法的有效性.     

Design Methodology of the Structure of Postal Express Mail Networks of Aviation Channels in China

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