时间相关穆斯堡尔谱与GaAs的119mTe离子注入

本文提出并实现了一种新的穆斯堡尔谱——时间相关穆斯堡尔谱。这是利用两步衰变^119mTe→¹¹⁹Sb→¹¹⁹Sn而获得的。测量了110keV ^119mTe加10¹⁵稳定Te/cm²注入并经600℃退火的样品在不同测量时间内的穆斯堡尔谱,分析了各谱线随ξ的变化。这里ξ是我们定义的参量,它等于Φ_Te/Φ_总,由退火时刻t_{a关键词：}     

ELECTRON TRANSFER IN PHOTOSENSITIZATION OF BIOMOLECULES BY ACRIDINE DYES

Abstract— The photosensitization of some biomolecules by proflavine was studied using the technique of electron paramagnetic resonance. It was shown that this process is directly influenced by the relative molar concentration of dye and substrate. For some values of these concentrations, a singlet associated with a radical form of proflavine is observed. The appearance of this signal is discussed in terms of electron transfer from an ionized proflavine molecule directly to another neutral dye molecule or via a molecule of substrate as an intermediate. It is shown that this transfer is facilitated by stacking. These results were compared with radiolysis of the same kind of complexes in frozen aqueous solution.     

A Note on Sampling from Combinations of Distributions

A rejection technique is described for sampling from a combinationof distributions with negative weights for some of the components.     

Application of a Direct Stiffness Method to Wave Propagation in Multiphase Poroelastic Media

In this paper, it is demonstrated how a direct stiffness method for wavepropagation in multilayered saturated poroelastic media, based on integraltransform techniques, can be modified to account for a small amount of gasin the pores. Unsaturated media with small gas fractions can be treatedusing Smeulders extension of Biots poroelastic theory. The effect of thepresence of gas bubbles on the fluid bulk modulus and the dispersioncharacteristics of a water-saturated sand of Mol is demonstrated. Thedirect stiffness method is illustrated with a numerical example wheretransient wave propagation in a dry, saturated and unsaturated halfspaceis considered.     

EFFICIENT COMPUTATIONS USING UPWIND BIASED SCHEMES

A new multiblock unfactored implicit upwind scheme for inviscid two-dimensional flow calculations is presented. Spatial discretization is carried out by means of an upwind first-order method; an original extension to higher accuracy is also presented. The integration algorithm is constructed in a ‘δ’ form that provides a direct derivation of the scheme and leads to an efficient computational method. Fast solutions of the linear systems arising at each time step are obtained by means of the bi-conjugate gradient stabilized technique. The computational results for super/hypersonic steady state flows illustrate the efficiency and accuracy of the algorithm.     

UH和UH_2分子的结构与势能函数

用相对论有效原子实势 (RECP)和密度泛函 (B3LYP SDD)方法研究了UH ,UH2 基态和低激发态的结构和势能函数 ,导出了分子的光谱数据 .结果表明 ,UH和UH2 的基电子状态分别为X4 Π和X3A2 ,离解能分别为 2 .886eV和5 .2 4 9eV ,UH2 具有C2v对称性 ,得到了UH和UH2 的几个不同的低激发态的结构与光谱数据 .应用多体项展式理论以及数字拟合方法 ,计算得到了UH分子和基态UH2 三原子分子的分析势能函数 ,该函数正确反映了UH和UH2分子的结构特征 ,可用于研究UHH的微观反应动力学 .     

BC_2N薄膜的柱状生长及生长机理

应用热丝辅助等离子体化学气相沉积法 (CVD)合成了表面呈柱状的BC2 N薄膜 ,X射线、红外及X射线电子能谱分析表明 ,薄膜的化学组分主要为BC2 N ,B ,C和N原子间互相结合成键 .扫描电镜观察到 ,薄膜表面形貌呈排列整齐、取向一致的柱体 ,并且发现这种生长方式与沉积参数密切相关 .最后从结合能方面讨论了柱状BC2 N的生长机理 .     

S.I.S.向量随机测度在弱拓扑及相容拓扑下的收敛性

本文主要研究ｓ．ｉ．ｓ．向量随机测度在弱拓扑及相容拓扑下的收敛性,给出了ｓ．ｉ．ｓ．向量随机测度在弱拓扑 容拓扑下的Ｖｉｔａｌｉ－Ｈａｌｍ－Ｓａｋｓ定理,作为应用,我们建立了Ｒ＾１－值有界可测函数关于Ｂａｎａｃｈ空间值ｓ．ｉ．ｓ．向量随机测度的随机积分的收敛定理,并得到了具ｔｙｐｅｐ的Ｂａｎａｃｈ空间中ｓ．ｉ．ｓ．向量随机测度的大数定律及中心极限定理。