相对论重离子碰撞的温度涨落与热容

使用LUCIAE3.0模型模拟了SPS能区Pb+Pb和C+C在不同能量(E_lab=20—200A GeV)和不同中心度下的重离子碰撞.并通过逐个事件的粒子温度涨落提取出了相应粒子的热容,发现对于同一碰撞系统,单位发射粒子的热容随碰撞能量的升高而下降直至饱和,随着碰撞参数b的增大而减小,而且发现单位发射粒子的热容具有随粒子质量的变大而变大的关系.同时还发现不同碰撞系统中同一种粒子具有相同的单位发射粒子热容,并给出了相应的解释.     

Molecular Structure and Affinity to 5-HT1A Receptor of Chlorophenyl(Piperazinylalkyl)Phthalimides

Abstract

X-ray crystallography, quantum-chemical calculations and conformational analysis have been employed to study chlorophenyl(piperazinylalkyl)phthalimides, potential ligands of 5-HT_1A receptor. The molecular recognition of investigated compounds by 5-HT_1Aserotonin receptor has been estimated according to their ability to inhibit the [³H8]-DPAT binding. The model for 5-HT_1A pharmacophore has been proposed based on crystal structures of N-(aryl)piperazinyl — alkylphthalimides.     

158A GeV的相对论重离子碰撞的强子快度分布及温度拟合

针对最近NA49在158A GeV的实验(C+C,Si+Si,Pb+Pb)数据,应用LUCIAE3.0模型进行模拟,得到了强子的快度分布和横向动量分布,并与实验数据进行比较,发现基本与实验数据相吻合。并对横向动量分布进行温度拟合,给出了和实验数据吻合很好的结果,但是对于重系统或重强子LUCIAE3.0给出的结果与实验符合相对较差.     

高能重离子碰撞中正负荷电粒子比单事例起伏研究

用强子和弦级联模型,JPCIAE及相应的Monte Carlo事例产生器,研究相对论性核–核碰撞中有限快度区间内正负荷电粒子比单事例起伏与能量、中心度、共振态衰变及快度间隔的关系.JPCIAE模型能够较好地符合CERN/SPS能区Pb+Pb碰撞的实验结果.本文还用此模型预言了RHIC能区Au+Au碰撞和ALICE能区Pb+Pb碰撞中的正负荷电粒子比单事例起伏.可以看出碰撞能量、中心度、共振态衰变及快度间隔对正负荷电粒子比单事例起伏的影响都不大.     

Theoretical Study of Hydrated Cd~（2＋） Interactions with Guanine

Theoretical study was performed to investigate how the hydration of cadmium ca-tion influences the structure and properties of guanine.The aqueous environment was simulated by both explicit solvent(1-5 water molecules) model and implicit solvent model.For complexes in which Cd2+ attached to the N(7) and O(6) sites of guanine,energy analysis together with the Natural Bonding Orbital(NBO) analysis were performed to elucidate the bonding characteristics in detail.The most stable structures are penta-coordinate complexes without aqua ligand located at the guanine site.Higher number of water ligands corresponds to higher stabilization energies.Average bonding energies of G-Cd increase with the number of water molecules.Bonding energies of water ligands depend on its position in the complexes.The charge distribution of guanine changed with increasing the number of water ligands,which may also influence the base-pairing pattern of guanine.There is positive charge transfer from guanine to aqua ligand as the number of the hydration waters increases.IEFPCM optimization has results comparable to the [CdG(H2O)5]2+ structure 5a.     

Preparation and Storage of Silver Nanoparticles in Aqueons Polymers

以水溶性聚合物为保护剂,采用化学还原法制备了银纳米粒子,分别利用透射电子显微镜、紫外可见光谱、同步光散射光谱等手段对其进行了表征,并探索了制备银纳米粒子的最佳实验条件。通过将银纳米粒子-聚合物溶液进行脱水,得到含有银纳米粒子的固态聚合物膜。将固态聚合物膜重新溶解于水,其水溶液的紫外可见光谱与脱水前的溶液进行了比较,发现两者性质并无明显差异。因此,将银纳米粒子分散固定在聚合物膜中是一种崭新而有效的银纳米粒子制备和存储方法。     

Special features of the alkylation of 7-bromo-5-(2-chlorophenyl)- 3-hydroxy-1,2-dihydro-3h-1,4-benzo- diazepin-2-one with alkyl tosylates

On interacting 7-bromo-5-(2-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin-2-one with methyl, hexyl, dodecyl, and cetyl tosylates, 1-alkyl-7-bromo-5-(2-chlorophenyl)-1,2,4,5-tetrahydro-3H-1,4-benzodiazepin-2,3-diones, and 1-alkyl-7-bromo-5-(2-chlorophenyl)-3-hydroxy-1,2-dihydro-3H-1,4-benzodiazepin- 2-ones were obtained. Only the dione was formed in the case of hexyl tosylate. On alkylating with methyl tosylate only the 3-hydroxy derivative was formed. It was shown that at pH 14 the 1-cetyl and 1-dodecyl-3-hydroxy derivatives were completely converted into the corresponding diones. The molecular and crystal structures of the compounds were established by X-ray structural analysis.     

Mass spectra of 1H-2,3-dihydro-1,4-benzodiazepine-2-thiones

The mass-spectrometric fragmentation of 1H-2,3-dihydro-1,4-benzodiazepine-2-thiones differs substantially from the fragmentation of the corresponding oxo derivatives with respect to the presence of [M - HCN]⁺ and [M - SH]⁺ ions. This is due to the tautomeric transformation of the molecular ions of the thiones to enethiol and eniminothiol tautomeric forms. The approximate percentages of each of the tautomeric forms were estimated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1412–1417, October, 1976.     

2-Aminqbenzophenone p-nitrophenylhydrazone structures

A series of 5-R-2-aminobenzophenone p-nitrophenylhydrazones has been made by condensing equimolecular amounts of p-nitrophenylhydrazine with 5-R-2-aminobenzophenones in the presence of HCl. These have been fractionated into syn and anti isomers by crystallization. The isomers have been assigned from IR and UV spectra, mass spectrometry, and x-ray structural analysis.Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 24, No. 5, pp. 553–562, September–October, 1988.