离子束引起的在Al／Cr双层薄膜界面处的原子混合

用600keV的Kr~ 离子轰击Al/Cr双层薄膜样品进行界面原子反应及相互混合的研究。实验样品是在单晶硅上蒸镀约500nm厚的铝膜,相继再蒸上所需厚度的铬膜而制成的。轰击剂量为2.0×10~(15)-2.5×10~(16)Kr~ /cm~2。用2.0MeVa粒子对轰击前后的样品进行了卢瑟福背散射(RBS)分析,发现界面处有明显的原子混合存在;当轰击剂量≥1.0×10~(16)Kr~ /cm~2时,RBS谱出现有明显的坪台,经拟合计算和x射线衍射(XRD)测量证实确有化合物Al_(13)Cr_2存在;还分别得到了原子混合量及混合效率与轰击剂量的关系;最后对界面处的原子混合机制进行了讨论。     

高压下氢化锂晶体中的离子间力与结合能公式的原子分子设计

本文提出一种利用材料Hugoniot数据研究高压下离子晶体中微观离子状态及其离子间排斥作用势的新方法。对氢化锂晶体进行研究时,我们得到Li~+和H~-离子之间排斥作用势函数,结果表明文献〔1〕中提出的离子压缩效应具有客观性。     

Fixed Point Theorems on Product Topological Spaces and Applications

A new collectively fixed point theorem for a family of set-valued mappings defined on product spaces of non-compact topological spaces without linear structure is proved and some special cases are also discussed. As applications, some non-empty intersection theorems of sets with convex sections and equilibrium existence theorem of abstract economies are obtained under much weaker assumptions. Our results includes a number of known results as many special cases.     

Recognizing the P4-structure of a tree

The P₄-structure of a graphG =(V,E) is a hypergraphH = (V,F) such that, for every hyperedgeA inF, the cardinality ofA is four and the subgraph of G induced byA is a path. It is proved in this paper that the P₄-structure of a tree can be recognized in polynomial time.     

一个在水稻胚胎中差异表达基因的分离鉴定

通过筛选水稻开花后48～50h的原胚和120～122h的分化胚的cDNA文库,得到一个在胚胎发育过程中表达有差异的克隆,命名为OsEES,测序结果显示OsEES含有一个预测的亚精氨合成酶结构域,编码一个大小约38×103(pI6.5)的蛋白.同时RNA原位杂交的结果显示开花48～50h的原胚中的信号强度明显大于开花120～122h的分化胚,表明OsEES可能在水稻胚胎发生过程中起到一定的调控作用.     

基于cDNA宏阵列的系统聚类分析猪发育阶段的基因表达谱

取杜洛克猪胚胎第33,45,55，65．75天的背最长肌样本．用cDNA Macroarray分析方法和聚类分析技术分析了327个EST在骨骼肌内不同发育阶段的基因表达谱．结果表明有98条EST在不同发育时期显著差异表达．第33天和第45天两阶段基因表达状态相似．第55天和第65天基因表达状态相似．而第75天的基因表达与第55天和第65天两个阶段的基因表达具有相近的聚类关系．表达状态相近，基因功能相似的基因大都被聚类在一起．     

Low-threshold, high-efficiency, high-repetition-rate optical parametric generator based on periodically poled LiNbO3

We report a high-repetition-rate optical parametric generator (OPG) with a periodically poled lithium niobate (PPLN) crystal pumped by an acousto-optically Q-switched CW-diode-end-pumped Nd:YVO_4 laser. For the maximum 1064nm pump power of 970mW, the maximum conversion efficiency is 32.9% under the conditions of 250℃, 1064nm pulse repetition rate of 22.6kHz and pulse width of 12ns, and the PPLN OPG threshold in the collinear case is less than 23.7μJ. The output power increases with the increase of the crystal temperature. The 1485－1553nm signal wave and 3383－3754nm idler wave are obtained by changing the temperature and the angle of the PPLN crystal.     

Decentered twisted Gaussian Schell-model beams and their propagation through a misaligned first-order optical system

The propagation properties of decentered twisted Gaussian Schell-model (DTGSM) beams passing through a misaligned first-order optical system are studied. The explicit expressions for the cross-spectral density function and Wigner distribution function of the output beam are derived, which retain their form unchanged. It is shown that the DTGSM beams preserve their closed property. The second-order moments matrix and the Wigner distribution function evolve with the usual laws, whereas the first-order moments matrix varies, as if a ray passes through such system. The propagation of DTGSM beams through an aligned first-order optical system is treated as the limiting case that corresponds to the vanishing misalignment parameters.     

<Emphasis FontCategory="NonProportional">L</Emphasis>-Matrices and solvability of linear complementarity problems by a linear program-Matrices and solvability of linear complementarity problems by a linear program

The classes ofL ₁-matrices,L ₂-matrices,L ₃-matrices andW-matrices are introduced to study solvability of a linear complementarity problem via solving a linear program. Three sufficient conditions are presented to guarantee that a linear complementarity problem is solvable via a linear program. The new sufficient conditions are weaker than the ones introduced by Mangasarian. This fact is also illustrated by an example. Partially supported by NSFC. This author is also with College of Business Administration of Human University as a Lotus chair professor.