The effect of angular-momentum dissipation on fluctuations of excitation functions in heavy-ion collisions

We discuss here the effect of dissipation of relative angular momentum on fluctuations of excitation functions in dissipative heavy-ion collisions. Dissipation and fluctuation of relative angular momentum modify and smooth the time-angle localization of the rotating dinuclear system. The secondary maxima in the energy correlation function of the cross-section shift to smaller values of the energy difference, the shift depending on the relaxation time and the diffusion coefficient for angular-momentum dissipation. The results are illustrated for the collision²⁸Si(E _lab=130 MeV)+⁴⁸Ti.Partly supported by the Alexander von Humboldt Foundation     

铜到钼的类钠离子能级结构及软X射线光谱理论计算

本文采用Hartree-Fock自洽场方法,从理论上计算了铜到钼的类钠离子1s~22s~22p~6nl(n=3～6,l=O～5)各能级能量。给出了有可能实现软X射线激光的跃迁(5g—4f,5f—4d,6g—4f,6f—4d)的光谱性质:跃迁波长、振子强度,并和实验值进行了比较,跃迁波长的相对误差不超过千分之二。从计算结果可知,Se的6f—4d跃迁,Br的6g—4f跃迁,Zr的5f—4l跃迁,Nb的5g—4f跃迁都已进入水窗波段。     

空间展布体系中由化学反应-扩散-热传导耦合导致的温度场对称破缺

分析了由于化学反应-扩散-热传导耦合而导致的非等温非均匀体系中温度场对称破缺.研究结果表明,在一定的边界条件下,甚至是单组分化学反应-扩散-热传导体系,温度场的这种自组织进程也不可避免.作为温度场结构的一个范例,进一步从解析解及计算机模拟两个方面研究了小展布非等温的Lindeman模型;结果表明,温度场出现时空自组织的阈值不仅与本征参数有关,而且与体系的边界条件及外控约束相关,揭示出了诱发或避免这种温度场时空自组织之途径.     

ORGANIC GEOCHEMISTRY OF ARTIFICIALLY HEATED SPHAGNUM COAL CONSIDERED AS POSSIBLE SOURCE ROCK FOR OIL AND GAS

A preliminary study of simulated thermal maturity has been conducted to evaluate the oil, gas and hydrocarbon generation potential of sphagnum coal in the Jinsuo brown coal basin, Yunnan Province and to understand the characteristics of the element composition and biomarkers in the course of thermal alteration. The experimental result was compared with that of xylitic coal, a kind of lithotype of soft brown coal. It is considered that sphagnum coal possesses the potential of forming economic accumulation of oil and gas. Its highest proportion of oil and hydrocarbon generation is 510 mg/g Corg. and 232.1 mg/g Corg. respectively. At an R_(ran)~° value of 2.51%, the ratio of gas generation from sphagnum coal attains to 620.5 ml/g Corg. In view of sphagnum coal being different from the conventional soft brown coal in various respects such as coal forming raw materials and enviroments as well as physico-chemical properties, it is Suggested as a special kind of source rock for coal-generated oil and gas.     

气相色谱-质谱联用法检测保健品中的违禁药物

近年来,随着社会消费水平的不断提高,保健品市场日益兴旺,但暴露出来的问题也十分严重。假冒配方、虚假广告、任意夸大其功效作用的宣传已为社会与公众所关注,而添加违禁合成药物、假化学成分达到或增加其功效作用的行为更具隐蔽性、欺骗性和危害性,为一般消费者所难以识别。因     

溶胶-凝胶法制备(Ca1-xMgx)SiO3陶瓷及其微波介电性能

以硝酸钙、硝酸镁、正硅酸乙酯为先驱体, 利用溶胶-凝胶法合成(Ca1-xMgx)SiO3(x=0.1、0.2、0.3、0.4、0.5)陶瓷粉体, 研究了Mg2+取代Ca2+对陶瓷物相组成、烧结特性以及微波介电性能的影响规律. 结果表明, Mg2+在CaSiO3中的最大固溶度不超过0.2；随着Mg2+对Ca2+取代量的增加, 陶瓷在烧结后的主晶相出现从CaSiO3相向CaMgSi2O6相的转变,陶瓷的烧结特性及介电性能出现先增加后下降的趋势；当x=0.3 时, 陶瓷体中CaSiO3相与CaMgSi2O6相共存, 克服了单相CaSiO3或CaMgSi2O6易成片长大的缺点,有效减少了陶瓷中残留的气孔, 提高烧结体致密性. (Ca0.7Mg0.3)SiO3在1320 益烧结后介电常数为6.62, 品质因数为36962 GHz.     

Synthesis, Structure and Conductivity of the New Charge-transfer Salt (ET)_2(CH_2=CH-CH_2-SO_3)·H_2O

ET is one of the most famous electron-donor molecules, which forms charge-transfer complexes (abbr. CT-complexes) with various types of counterions. These complexes have received intense attention because a wide range of physical properties such as conductivity and superconductivity1, ferromagnetism2-4 and nonlinear optical properties5 was found in these materials. Although the majority of the ET-based CT-complexes were prepared by combining with inorganic counterions, CT-complexes with o…     

聚己内酯和聚氧化乙烯共混体系中的两类片晶相间堆砌

对聚(ε-己内酯)(PCL)/聚氧化乙烯(PEO)共混物的相差显微镜、广角X-射线衍射(WAXD)、小角X-射线散射(SAXS)及示差扫描量热计(DSC)等的研究表明,只有当共混物中PCL(或PEO)的含量低于20％时,两组份是相容的.当PCL含量低于20％时,在共混物中形成了PEO片晶和PCL片晶相间堆砌的结晶形态,当PEO含量不超过20％时,PEO则完全以非晶形式混入PCL的非晶区,同时阻碍了PCL的结晶.可见在结晶过程中,相容的两组份对共混体系形态结构的影响却不尽相同.     

A Novel Catalyst for Liquid Phase Hydrogenation of m-Dinitrobenzene to m-Phenylenediamine

A novel lanthana-promoted nickel catalyst supported on silica for the liquid phase hydrogenation of m-dinitrobenzene to m-phenylenediamine was prepared by an incipient wetness sequential impregnation method. It was found that Ni-La/SiO2 catalyst exhibited high activity and stability for m-dinitrobenzene hydrogenation. Over this catalyst, the conversion of m-dinitrobenzene and the yield of m-phenylenediamine were up to 97.1% and 93.5%, respectively,at 373 K and 2.6 MPa hydrogen pressure after reaction for 1 h.     

Furostanol saponins with inhibitory action against COX-2 production from Tupistra chinensis rhizomes

Two furostanol saponins were obtained from the n-butanol fraction of methanol extract from Tupistra chinensis rhizomes,a folk medicine of Shennongjia Forest District of Hubei Province.Their structures were determined as (25S)-26-O-(β-D-glucopyranosyl)- furost-1β,3β,22α,26-tetrol-3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glucopyranoside (1) and (25R)- 26-O-(β-D-glucopyranosyl)-furost-1β,3β22α,26-tetrol 3-O-β-D-glucopyranosyl-(1→4)-β-D-glucopyranosyl-(1→2)-β-D-glu- copyranoside (2),on basis of chemical and spectroscopic evidences.1 and 2 displayed marked inhibitory action towards COX-2 production in macrophages of the rat abdomen induced by LPS at 20μg/mL.