半导体单晶硅的离子束蚀刻实验研究

离子束蚀刻是一种有超精细加工能力的微细加工技术,广泛应用于微电子、光子技术、表面科学等领域。硅及其化合物常用来制作大规模集成电路,在其表面蚀刻出具有一定几何布图尺寸的沟槽。其深度、宽度、边壁倾角及槽底形状等直接影响器件的性能。     

MeV Pb离子在非晶Si中的射程离散──离子束混合和增强扩散的影响

１．０ＭｅＶ２０８Ｐｂ离子在非晶Ｓｉ中的投影射程ＲＰ和射程偏差ΔＲＰ作为注量和温度二者的函数用背散射法进行测定．注量的变化范围为５×１０１３～７×１０１４ｃｍ－２．注入是在室温和ｔ＝－１２０℃下完成的．由由实验所确定的投影射程，射程偏差与注量或温度无关，并且分别等于２９５和７２．２ｎｍ．与ＴＲＩＭ８６的计算结果相比较，发现ＲＰ的偏离为１８％，而ΔＲＰ的偏离为３６％．ＲＰ和ΔＲＰ二者与注量及温度的无关性，排除了所观察到的与ＴＲＩＭ的矛盾是由于注入期间辐射增强扩散或离子束混合效应而引起的解释。     

镁改型蛭石对铵离子的交换性能

对经人工改型所得的镁型蛭石进行了铵离子交换性能的研究．在不同pH值下测定了镁型蛭石对NHr的全交换容量，在不同温度下测定了样品的平衡等温线．结果表明，镁型蛭石对NH4^ 的交换总量随pH值的变化而波动，在pH值为7时其交换总量为59．32mmol／100g，其选择性随温度的降低而升高，这为蛭石作为一种新型填料提供了一定的理论依据。     

我国排球后备人才的培养与市场管理交流体制

分析了社会转型期我国排球后备人才的培养以及市场交流管理体制，认为我国排球后备人才培养体制由单一、封闭模式向多元、开放模式发展，建立多渠道、多形式的多元培养体制是大势所趋；传统的排球后备人才管理体制存在各种弊端，建立切实可行的排球后备人才流动市场体制，实现人才的最佳化流动，最大限度地合理使用排球后备人才，是提高后备人才使用率和成材率的关键。     

Parity Nonconservation in of Multiply Dielectronic Recombination Charged Ions

A parity nonconserving （PNC） asymmetry in the cross section for dielectronic recombination of polarized electrons on multiply charged ions with Z≥40 is discussed. This effect is strongly enhanced for close doubly-excited states of opposite parity in the intermediate compound ion. Such states are known for He-like ions. However, these levels have large energy and large radiative widths which hampers observation of the PNC asymmetry. We argue that accidentally degenerate states of more complex ions may be more suitable for the coresponding experiment.     

Ab initio study of the effects of Ag/Mn doping on the electronic structure of LiFePO_4

Based on density functional theory (DFT) of the first-principle for the cathode materials of lithium ion battery, the electronic structures of Li(Fe1-xMex)PO4 (Me = Ag/Mn, x = 0―0.40) are calculated by plane wave pseudo-potential method using Cambridge serial total energy package (CASTEP) program. The calculated results show that the Fermi level of mixed atoms Fe1-xAgx moves into its conduction bands (CBs) due to the Ag doping. The Li(Fe1-xAgx)PO4 system displays the periodic direct semiconductor characteristic with the increase of Ag-doped concentration. However, for Fe1-xMnx mixed atoms, the Fermi level is pined at the bottom of conduction bands (CBs), which is ascribed to the interaction be-tween Mn(3d) electrons and Fe(4s) electrons. The intensity of the partial density of states (PDOS) near the bottom of CBs becomes stronger with the increase of Mn-doped concentration. The Fermi energy of the Li(Fe1-xMnx)PO4 reaches maximum at x = 0.25, which is consistent with the experimental value of x = 0.20. The whole conduction property of Mn-doped LiFePO4 is superior to that of Ag-doped LiFePO4 cathode material, but the structural stability is reverse.     

我国城市贫困的权利理论探微

运用印度经济学家阿玛蒂亚·森的权利理论,分析了中国城市贫困群体的权利现状。除以生产为基础的权利无从谈起外,以贸易为基础的权利、自己劳动的权利、继承与转移的权利都在不同程度上恶化,这是城市贫困群体出现和扩大的根本原因。从权利理论的视角反贫困,政府的工作重点应当是采取多种手段和措施改善除以贸易为基础的权利以外的三种权利。     

The performance of non‐linear exchange rate models: a forecasting comparison

In recent years there has been a considerable development in modelling non‐linearities and asymmetries in economic and financial variables. The aim of the current paper is to compare the forecasting performance of different models for the returns of three of the most traded exchange rates in terms of the US dollar, namely the French franc (FF/$), the German mark (DM/$) and the Japanese yen (Y/$). The relative performance of non‐linear models of the SETAR, STAR and GARCH types is contrasted with their linear counterparts. The results show that if attention is restricted to mean square forecast errors, the performance of the models, when distinguishable, tends to favour the linear models. The forecast performance of the models is evaluated also conditional on the regime at the forecast origin and on density forecasts. This analysis produces more evidence of forecasting gains from non‐linear models. Copyright © 2002 John Wiley & Sons, Ltd.     

膜结构裁剪及展开的修正二次测地线法

对膜结构裁剪分析中目前应用较广的裁剪线的生成方法进行了比较研究，提出修正二次测地线法。确定了采用测地线作为裁剪线及展开图形的基准线。之后对已有图形展开方法——二次测地线法做了适当改进，提出修正二次测地线法。     

提高石油化工企业原料利用率的技术研究

坚持眼睛向内,挖潜增效,这是当前原油变重、供应量不足,生产资料涨价的客观形势下走出困境、提高企业效益的主要途径之一,本文从拓宽催化回炼油的利用途径,催化和加氢裂化互换循环油加工,优化重油原料的安排,提高轻油头的化肥效益,挤出烷基化原料,开发异丁烷的化工用途及油化结合等方面,分析通过厂际装置间的原料互供、生产优化来挖掘企业内涵,提高经济效益.