激光等离子体非平衡X射线发射谱理论研究

在平均离子模型的基础上,发展了一个计算离子组态概率分布的有效方法,称为统计方法.根据激光靶耦合程序模拟给出腔靶等离子体状态条件,研究1.06μm激光金等离子体的非平衡离子组态分布和X射线发射谱特性.得到与实验谱相同的能带范围,并得出在激光等离子体中多电子同时处于激发态的离子组态对X射线发射的贡献不能忽略的结论. 关键词：     

INFLUENCE OF DETUNING ON THE BUTTERFLY EFFECT OF LASER OSCILLATION

In this paper the butterfly effects of single mode laser oscillation are studied. It is shown that the detuning between laser oscillation and atomic transition frequency leads to a decrease in second threshold, which makes the demonstration of chaos theory in experiment easy.     

掺杂C60的SiO2气凝胶的制备及荧光特性研究

利用“化学掺杂”方法，制备掺杂C₆₀-SiO₂气凝胶，对掺杂C₆₀-SiO₂气凝胶的红外吸收光谱、飞行时间质谱的测试表明C₆₀分子被成功地掺入SiO₂气凝胶中．室温条件下，在Ar⁺激光（488nm）激发下，观察到掺杂C₆₀-SiO₂气凝胶有很强的可见发光现象，发光峰位较纯C₆₀发光明显蓝移 关键词：     

掺铒SiOx的光致发光特性

利用分子束外延设备生长了掺铒SiO_x,观察到铒掺入的同时O的掺入效率也得到提高.铒可以促进氧的掺入的原因是铒与氧在硅衬底表面反应，以络合物形式掺入硅中，从而提高了硅中氧的浓度.测量了铒在SiO_x中的光致发光特性，结果表明掺铒的SiO_x的发光强度从18K到300K仅下降了约1/2，这说明Er掺在SiO_x中是一种降低发光强度的温度淬灭效应的途径，最后讨论了温度淬灭的机制. 关键词：     

CEMS和慢正电子束研究ZrO2(Y)中Fe的热动力学行为

用内转换电子穆斯堡尔谱（ＣＥＭＳ）和慢正电子束研究了含３％Ｙ₂Ｏ₃的ＺｒＯ₂中⁵⁷Ｆｅ离子（１００ｋｅＶ，３×１０¹⁶ａｔ．／ｃｍ²）注入态及其在氢气氛中退火的热力学行为．注入态以Ｆｅ³⁺，Ｆｅ²⁺和Ｆｅ⁰存在，它们分别是Ｆｅ³⁺-Ｖ（空位）复合体、二聚体和超顺磁颗粒．经４００，５００℃退火后，Ｆｅ³⁺-Ｖ分解，分别出现了α-Ｆｅ的前期相和α-Ｆｅ纳米颗粒．含Ｆｅ的ＺｒＯ₂（Ｙ）混合导电的出现可能是和Ｆｅ的不同价态及其相对含量有关 关键词：     

软X射线多层膜单色器能量分辨研究

从理论上分析了影响软X射线多层膜单色器能量分辨率的机制，给出了一种既能提高多层膜能量分辨率又不影响其反射率的膜材选择规则．并给出近年来在北京同步辐射装置上开展多层膜单色器应用研究的结果 关键词：     

分子束外延及溅射法制备Co/Cu多层膜结构与磁电阻的比较研究

对用分子束外延（MBE）和溅射方法制备的Co/Cu多层膜样品分别进行了结构及磁性研究．X射线分析表明两者均有良好的调制周期性，并且前者形成外延单晶结构，铁磁共振研究表明了面内六次各向异性对称的存在，说明此超晶格具有完整的面内二维结构．磁电阻测量发现，溅射制备的多层膜具有较高的磁电阻值并明显地随Cu层厚度而振荡，相应的室温磁电阻峰值分别为27%，24%，14%；而MBE制备的超晶格的磁电阻较小，其第二峰的数值只有7%．MBE超晶格界面处可能具有超顺磁性，对磁电阻和磁化强度的不同的外场依赖关系有一定的影响． 关键词：     

Ni,Pd和Pt的表面应力

半经验的修正嵌入原子方法用于Ni，Pd和Pt的低指数面的表面应力计算，得到了与第一原理计算相符合的结果．给出了（110）表面［110］方向的应力是［001］方向应力的两倍左右；阐明了应力各向异性是所有fc金属（110）面的一般特性．预言了Pd和Pt（100）的表面应力的大小． 关键词：     

Parallel solution of variational inequality problems with nonlinear source terms

Current address: Department of Mathematics, University of California at Los Angeles, CA 90095-1555 and Computing Centre, Academia Sinica, People's Republic of China. The work of this author was supported by the Alexander von Humboldt Foundation. Using the finite-element method to discretize the variationalinequality problems related to some free boundary problems withnonlinear source terms, we then solve the resulting algebraicsystems by the combination of the quasi-Newton method and thedomain decomposition techniques. The numerical solution processesare completely parallelizable. Both the convergence of the finite-elementapproximation and of the parallel iterative processes are proved.     

Molecular and genomic characterization of pathogenic traits of group A Streptococcus pyogenes

Group A streptococcus (GAS) or Streptococcus pyogenes causes various diseases ranging from self-limiting sore throat to deadly invasive diseases. The genome size of GAS is 1.85–1.9 Mb, and genomic rearrangement has been demonstrated. GAS possesses various surface-associated substances such as hyaluronic capsule, M proteins, and fibronectin/laminin/immunoglobulin-binding proteins. These are related to the virulence and play multifaceted and mutually reflected roles in the pathogenesis of GAS infections. Invasion of GAS into epithelial cells and deeper tissues provokes immune and non-immune defense or inflammatory responses including the recruitment of neutrophils, macrophages, and dendritic cells in hosts. GAS frequently evades host defense mechanisms by using its virulence factors. Extracellular products of GAS may perturb cellular and subcellular functions and degrade tissues enzymatically, which leads to the aggravation of local and/or systemic disorders in the host. In this review, we summarize some important cellular and extracellular substances that may affect pathogenic processes during GAS infections, and the host responses to these.