高压热处理对氧沉淀低温形核的影响

研究了外加高压(1GPa)下对450℃热处理硅片中氧沉淀行为的影响.透射电镜观察表明相对于大气压下热处理的样品,高压处理的样品会产生密度更高、尺寸更小的氧沉淀,表明高压有利于小直径氧沉淀的生成.电学性能测试表明,高压下处理的样品其热施主生成浓度和生成速率远远高于常压下处理的样品,这表明热施主与低温热处理过程中生成的高浓度氧沉淀核心有密切的关系.     

基于OTA的多功能电压模滤波器及其仿真

本文采用信号流图法设计了一种基于ＯＴＡ的三输入一输出多功能电压模滤波器新电路，该电路由五个ＯＴＡ和两个接地电容构成，合理选择输入电压可实现低通、高通、带通、带阻及全通滤波功能。文章还对电路进行了ＭＯＳ管级的计算机仿真，其结果表明所提出的电路方案正确有效。     

双电荷交换反应与双重子共振态

提出了核双电荷交换反应的双重子共振态的反应机制,成功地解释了长期以来一直困惑着人们的共振区反应的角分布的实验结果.说明了共振区核双电荷交换反应是寻找双重子共振态的一个可能的途径.     

Generalized indices of operators inB(H)

A generalized dimension is further developed. Here subtraction and addition of two generalized dimensions are defined, so that the operations: ∞ ± n = ∞, ∞ + ∞ = ∞, which used to play an inflexible role, are refined and moreover, ∞ - ∞, which used to be meaningless, is done in sense. Then generalized index for semi-Fred-holm operators is developed to wholeB(H), i.e. all of bounded linear operators in Hilbert spaceH. Theorem 2.2 is proved with an example, which is in contradiction to a known proposition for semi-Fredholm operators in form, practically a refined result of the known proposition. Then, it is proved thatB(H) is the union of countably many disjoint arewise connected sets over all the generalized dimensions ofB(H). Project supported by the National Natural Science Foundation of China     

QUENCHING PROBLEMS OF DEGENERATE FUNCTIONAL REACTION-DIFFUSION EQUATION

This paper is concerned with the quenching problem of a degenerate functional reaction-diffusion equation. The quenching problem and global existence of solution for the reaction-diffusion equation are derived and, some results of the positive steady state solutions for functional elliptic boundary value are also presented.     

Validation of an optimization procedure to improve low frequency characteristics of rooms

A set of experiments was carried out to validate an optimization procedure based on finite element method (FEM). The idea of the procedure, fully presented in previous edition of this journal [Zhu X, Zhu Z, Cheng J. Using optimized surface modifications to improve low frequency response in a room. Appl Acoust 2004;65:841-60], is to produce an optimal geometry modification on the wall for improving low frequency sound uniformity in small rooms. Four experimental models were set up with a scale of 1:5. One was modified according to the optimized result and the others were treated with no optimization consideration. Measured frequency responses of four rooms were compared with numerical results calculated by FEM models. The transient responses in these rooms were also measured and analyzed. The agreements between calculation and measurement are satisfactory though the discrepancies due to the uncertainty of acoustic behavior of the room boundaries remain. The optimization procedure has been supported by the results that the optimized room produces the flattest frequency response and also the most smooth energy decay within the frequency range studied. The reductions of response fluctuation have reached 4.3 dB for prediction and 2.6 dB for measurement, respectively.     

薄相屏闪烁的数值分析

本文在弱闪烁条件下，利用广泛适用于星际闪烁、行星际闪烁和电离层闪烁的薄相屏理论，以行星际闪烁为算例，对薄相屏闪烁进行了数值分析。结果表明：垂直于介质运动方向上的不规则结构的大小对闪烁有着重要的影响，直接表现在频谱的变化趋势和振荡幅度的不同。尤其是当小于Ｆｒｅｓｎｅｌ尺度时，数值计算表明此时没有闪烁发生。     

高质量的一级光栅1．55μmDFB激光器

本文详细叙述了ＤＦＢ激光器的设计要点和新的工艺。采用一级全息光栅和二步液相外延法批量研制出高稳定单纵模工作的１．５５μｍ分布反馈激光器（ＤＦＢ—ＬＤ）。外延片成品率＞４０％。器件特性：２５℃时阈值电流２０ｍＡ，单面光功率＞１０ｍｗ，主边模抑制比ＳＭＳＲ达４３ｄＢ（λ／４相移光栅），谱线宽度△ν－２０ｄＢ＝０．３ｎｍ，调制速率＞１．８ＧＨｚ。可靠性测试显示：高温监测光谱稳定，２５°Ｃ时阈值退化率△Ｉｔｈ／ｔ＜０．３ｍＡ／ｋｈ，对应器件预估寿命将超过１０万ｈ。     

Suppression of boron penetration in p+ polysilicon gateP-MOSFETs using low-temperature gate-oxide N2O anneal

It has been reported that high-temperature (~1100°C) N₂ O-annealed oxide can block boron penetration from poly-Si gates to the silicon substrate. However, this high-temperature step may be inappropriate for the low thermal budgets required of deep-submicron ULSI MOSFETs. Low-temperature (900~950°C) N₂O-annealed gate oxide is also a good barrier to boron penetration. For the first time, the change in channel doping profile due to compensation of arsenic and boron ionized impurities was resolved using MOS C-V measurement techniques. It was found that the higher the nitrogen concentration incorporated at Si/SiO₂ interface, the more effective is the suppression of boron penetration. The experimental results also suggest that, for 60~110 Å gate oxides, a certain amount of nitrogen (~2.2%) incorporated near the Si/SiO₂ interface is essential to effectively prevent boron diffusing into the underlying silicon substrate     

浅析数据挖掘与企业市场营销战略

数据挖掘是客户关系管理的重要组成部分,而客户关系管理的核心是营销管理。在高度信息化的社会的今天,数据挖掘在市场营销决策中起到越来越重要的作用,通过它可以实现对客户深度的把握,研究老客户,发现新客户,让企业实时把握住市场动态,及时地调整企业的营销策略,以在激烈的市场竞争中立于不败之地。