CSR外靶实验终端中子流测量的模拟

随着兰州重离子加速器冷却储存环(HIRFL-CSR)外靶实验终端中子墙的建立, 为实验测量高能中子提供了机遇. 为确定CSR外靶实验终端对中子流测量的可行性, 基于BUU理论模型分别对对称系统(Ni+Ni, Pb+Pb)和非对称系统(Pb+Ni)进行了模拟计算, 发现当系统能量达到几百MeV/u时, 中子流信号相当明显, 并与碰撞参数有明显的依赖关系. 模拟结果表明, 在前角20°的覆盖范围内, 可以较好地实现中子流测量所需要的反应平面确定及碰撞参数选择. 对双击事件及其对中子流的影响进行了简单的讨论.     

On the topological representation of catalytic cycles with nonlinear steps

Reaction route analysis is applied to visualize reaction networks in several heterogeneous catalytic reactions. Combination of the theory of complex reactions with the notion of catalytic cycles results in a topological representation of complex mechanisms with the nodes comprising all possible surface species including free sites and branches indicating interconnections between reactions.     

Regiochemistry of the addition of mercury salts to bornylene

The dependence of the regiochemistry of the mercuration of bornylene on the nature of the mercurating reagent and on the solvent has been found. The structures of the intermediate and transition state in these reactions have been proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 501–505, March, 1994.     

Synthesis of vinyl-substituted oxiranes and their transformation to dihydrofurans

The reaction of dimethylsulfonium methylide with the carbonyl function of 2-arylidene-cyclohexanones obtained from 2-methylcyclohexanone affords the corresponding spirooxiranes. The application of this reaction to 2,2-dimethyl-6-(5-methylfurfurylidene)cyclohexanone and 2,2-dimethyl-6-(5-chlorofurfurylidene)cyclohexanone leads to substituted 4,4-dimethyl-1-furyl-1,-3,4,5,6,7-hexahydroisobenzofurans.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1439–1443, August, 1994.     

Thermal reaction of clCH2CONH2 in molten acetamide

Mixtures composed of amides and electrolytes exhibit interesting properties such as viscoelastic behaviour and a megavalue of the dielectric constant. In order to improve the dielectric properties, the authors are investigating a large number of molten mixtures of CF₃COONa with different types of amides, including the ternary system sodium trifluoroacetate-chloroacetamide-acetamide. The experimental measurements showed that the ternary mixtures are thermally unstable. A yellow oily product is formed; this was purified and tested by means of IR and NMR techniques. The formula and the kinetic mechanism are proposed.     

基于偶联反应新极谱法测定痕量亚硝酸根的研究——Ⅱ.以苯酚为偶联试剂

本文研究了苯酚在氨性缓冲溶液中与NO_2~--磺胺重氮盐偶联反应的实验条件,建立了一个灵敏快速测定痕量NO_2~-的新方法。NO_2~-离子浓度在1.0×10~(-10)～4.8×10~(-7)g/ml范围内,与峰高呈良好的线性关系.4000倍量NO_3~-存在不干扰.     

An analysis of the radiation reaction in a charged dumbbell

We make a thorough non-covariant analysis of the derivation of the equation of motion for a charged particle, including radiation reaction, by means of a simple model for the charge: a dumbbell. This model and our method to expand retarded quantities, based on complex-variable theory, allow us to avoid some of the usual approximations, so we can show several features of the radiation reaction problem.     

Michael-Addition Reaction of Malononitrile with a,β-Unsaturated Cycloketones Catalyzed by KF/Al_2O_3

The utility of fluoride salts as potential base in a va-riety of synthetic reactions has been recognized in re-cent years.1 However, low solubility of fluoride salts in ordinary solvents hampers their wide applications in organic synthesis. On the other hand, there has been increasing use of inorganic solid supports as catalysts for many years2 resulting in higher selectivity, milder reaction conditions and easier work-up. Especially po-tassium fluoride-coated alumina (KF-alumina) has been a …