非对称核物质中同位旋对称势的动量和密度依赖性

在Brueckner-Hartree-Fock理论框架内, 研究了同位旋非对称核物质中质子和中子单粒子势的动量相关性及其随同位旋非对称度的变化, 在此基础上计算了同位旋对称势, 并讨论了三体核力的影响. 结果表明同位旋对称势对于同位旋非对称度的依赖性很弱, 但对于动量和密度均有较强的依赖性. 当密度固定时, 同位旋对称势随动量增加而减小. 尽管三体核力对于质子和中子单粒子势的动量相关性有较大影响, 但对同位旋对称势的影响很小. 还与目前重离子碰撞输运理论模型中所使用的各种参数化的唯象对称势进行了比较.     

Pt（IV）修饰的非晶态TiO2对2，4-二氯苯氧基乙酸的可见光降解

用溶胶-凝胶法制备了在可见光照射下具有光催化活性的掺杂P（t Ⅳ）离子的非晶态微孔TiO2，表面积为160～200 m2/g；含3.0%Pt（Ⅳ）的AMM-Ti具有最大的光催化活性. X射线精细结构分析（EXAFS）表明，单个的PtCl4分子均匀地分布在非晶态二氧化钛表面；用这种光催化剂降解2，4-二氯苯氧基乙酸时，2，4-二氯苯酚是主要的中间物，通过Langmuir-Hinshelwood 方程的线性形式估算了反应速率常数k 和吸附平衡常数K，研究了光催化起始反应速率和反应物起始浓度之间的关系，同时，提     

软x射线近贴显微技术

软x射线近贴显微技术不但可使活的生物样品成象,分辨率高于光学显微镜,而且人为的样品准备程序在该技术中都可避免。本文描述了用高功率激光打靶产生的等离子体作为软x射线源而进行的近贴显微研究,并得到了分辨率好于1μm的结果。     

北京同步辐射装置3B1B生物光谱实验站

本文介绍北京同步辐射装置（ＢＳＲＦ）３Ｂ１Ｂ光束线、生物光谱实验站和圆二色谱仪的基本情况。报道北京正负电子对撞机（ＢＥＰＣ）同步辐射专用光期间，我们在站测量了１１种手征性生物和药物样品的圆二色（ＣＤ）谱，首次在国内利用同步辐射光获取了Ｄ－苯丙氨酸等样品的ＣＤ谱和Ｄ－及Ｌ－亮氨酸对称的ＣＤ曲线。     

高效蛋白质浓缩剂的制备及浓缩作用的研究

采用自由基水溶液聚合方法合成了超高分子量的丙烯酸（钠）聚合物。该聚合物具有高达几十倍至上千倍的吸水能力，通过适当控制聚合物的交联度使其成为具有一定孔径的网状物，可用于生物大分子，如：蛋白质溶液或其它生物提取液的浓缩。试验了用反透析法浓缩胰蛋白酶的方法，与直接加入浓缩法相比，能够更好地保持酶的活性。与传统的浓缩方法相比，用该方法浓缩蛋白质具有效率高，浓缩剂用量少的优点。     

CexGdyTb1-x-yP5O14晶体生长及其光谱

采用蒸发溶液法从磷酸溶液中生长出一系列CexGdyTb1-x-yP5O14晶体.测定了它们的结构.它们属于单斜晶系,空间群P21/c.测定了Ce0.9Gd0.1P5O14、Ce0.9Tb0.1P5O14和La0.8Gd0.1Tb0.1P5O14等晶体的光谱.首次观察到,将Gd加入CexTb1-xP5O14晶体中形成.CexGdyTb1-x-yP5O14时阻碍了Ce3+→Tb3+的能量传递,导致Ce3+的发射峰增强,Tb3+的5D4-FJ发射峰减弱、而5D3-7FJ发射峰增强.     

HBTMPTP与伯胺N1923对稀土元素(Ⅲ)的协同萃取

研究了二（2，4，4-三甲基戊基）单硫代膦酸（HBTMPTP，HL）和伯胺N1923的正己烷溶液从硫酸介质中对稀土元素（Ⅲ）的协同萃取．并以La（Ⅲ）为例，用斜率法、恒摩尔法和饱和法确定了协萃配合物的组成为（RNH3）3L2La（SO4）2，计算了协萃配合物的生成常数及热力学函数，观测了协萃配合物的IR谱．     

Electronic Structure and Magnetic Properties of SmCo7-xZrx

The electronic structure and magnetism of SmCo_7-xZr_x alloy are investigated using the spin-polarized MS-X. method. The results show that a few of electrons are transferred to the Sm(5d⁰) orbital due to orbital hybridization between Sm and Co atoms. The exchange interactions between 3d and 5d electrons are more important than the polarization effects of the conductive electrons, thus it is the main reason resulting in the long-range ferromagnetic order in SmCo_7-xZr_x. The Curie temperature of SmCo_7-xZr_x is generally lower than that of corresponding pure Co, which may be explained by the weaker average coupling strength between Co lattices due to some negative couplings mainly occurring of 2e site. The calculated results for the Sm₅Co₃₂Zr₂ cluster may lead to a better understanding of why SmCo_7-xZr_x is stable phase. Since the spin-up DOS peak of d electrons at E_F arises and the bonding of electrons at E_F strengthens with increasing Zr concentration, which results in the internal energy of the system decrease, the stable ferromagnetic order forms in SmCo_7-xZr_x.     

Cyclic BSEC of block size 3

Balanced sampling plans excluding contiguous units (or BSEC) were first introduced by Hedayat, Rao and Stufken in 1988. In this note, we discuss constructions of these designs having cyclic automorphisms. We use Langford sequences to construct all possible cyclic BSEC (or CBSEC) with block size 3 and λ = 1,2, which establishes the necessary and sufficient conditions for such designs. Some constructions of the balanced sampling plan avoiding adjacent units, a generalization of BSEC, are also given for fixed λ.     

Behaviors of the positive temperature coefficient of resistance of poly(styrene‐co‐n‐butylacrylate) filled with Ni‐plated core‐shell polymeric particles

Conductive composite films of poly(styrene‐co‐n‐butylacrylate) copolymers filled with low‐density, Ni‐plated core‐shell polymeric particles were prepared and their behaviors of positive temperature coefficient of resistance (PTCR) were investigated. When the conductive fillers in the composite film were loaded beyond the critical volume, 10 up to 25 vol %, composite films exhibited a unique electrical resistant transition behavior, which the electrical resistance rapidly increased by several orders of magnitude at the critical temperature. The PTCR transition temperature, in general, occurred before the glass transition temperature of polymer matrix. Further increased the conductive filler loading to 30 vol %, the overpacked conduction paths were formed in the entire composite and the PTCR effects became blurred. While the composite film treated with thermal cycle several times from room temperature up to 120 °C, the electrical resistivity increased accompanied with the shift of the PTCR transition to lower temperature. The reason might have been caused by the formed interfacial cracks within the composite film. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 322–329, 2007