Charged Multiplicity Density and Number of Participant Nucleons in Relativistic Nuclear Collisions

The energy and centrality dependencies of charged particle pseudorapidity density in relativistic nuclearcollisions were studied using a hadron and string cascade model, JPCIAE. Both the relativistic p+p experimental dataand the PHOBOS and PHENIX Au+Au data at RHIC energy could be fairly reproduced within the framework ofJPCIAE model and without retuning the model parameters. The predictions for Pb + Pb collisions at the LHC energywere also given. We computed the participant nucleon distributions using different methods. It was found that thenumber of participant nucleons is not a well defined variable both experimentally and theoretically. Thus it may beinappropriate to use the charged particle pseudorapidity density per participant pair .as a function of the number ofparticipant nucleons for distinguishing various theoretical models.     

相对论重离子碰撞中Λ粒子产生和Λ/p比率

利用强子输运–弦碎裂模型研究了200A GeV重离子碰撞中Λ多重产生和Λ/p比率.研究了它们随反应系统大小和碰撞中心度的变化.研究表明Λ和p多重数都随反应系统增大和随碰撞中心度提高而增大,但它们的比率基本保持不变.Λ的湮没截面大小变化对Λ的多重数产生有一定影响,但对Λ/p比率影响不大.结果很好地再现了pp反应中Λ/p比率.并获得这一比率在AA反应中是pp反应中的3—5倍.     

ALADIN热曲线的微正则系综分析

用微正则瞬时多碎裂统计模型分析了ALADIN热曲线.结果表明落在ALADIN热曲线温度平台(温度扭曲)附近的弹剩余核(热核)的理论代表点,并不落在相应弹剩余核热曲线的温度平台(扭曲)范围内,从而对ALADIN热曲线是否可作为核液气相变的证据提出质疑.     

Measuring deuteron beam parameters with solid-state track detectors in experiments with the QUINTA target assembly

The results of measurements of the beam parameters on the target upon irradiation of the QUINTA subcritical uranium assembly with deuterons with energies of 1, 4, and 8 GeV are presented. Data on the position of the incident particle beam relative to the assembly axis and on the actual geometric parameters of the beam make it possible to analyze information on the spatial distributions of reaction rates within the target assembly correctly, comparing such distributions obtained at different irradiation sessions and modeling the experiments with the use of MCNPX, GEANT4, FLUKA, and other similar software tools.     

A Global Method for Relaxation in W1,p and in SBVp

 An integral representation formula for a class of functionals defined on and in (the space of special functions of bounded variation) is obtained without requiring the regularity conditions usually imposed in the literature. The approach is based on the general results of [10] and on a Poincaré-Wirtinger type inequality introduced by DE GIORGI, CARRIERO & LEACI [25]. Applications to relaxation problems and dimension-reduction problems in brittle thin films are presented. (Accepted May 8, 2002) Published online October 18, 2002 Communicated by L. Ambrosio     

酶促聚合和原子转移自由基聚合“一锅法”合成嵌段聚合物及其性能表征

用酶促聚合和原子转移自由基聚合相结合的"一锅法"合成了聚甲基丙烯酸正丁酯嵌段聚10-羟基癸酸[PBMA-b-P(10-HD)],通过核磁共振(1H NMR)、傅里叶红外光谱(FTIR)和凝胶渗透色谱(GPC)对其结构以及分子量与其分子量分布进行了表征,并通过动态光散射仪(DLS)和原子力显微镜(AFM)对聚合物在水溶液中的性质进行了研究.所得嵌段聚合物纳米粒子呈球形结构,平均直径为135 nm左右.     

Application of Alkali Metal Hydroxides for the Preparation of gem‐Chlorophenylcyclopropanes

gem‐Chlorophenylcyclopropanes 3 are conveniently prepared by reaction of benzal chloride (1) with alkenes 2, carried out either in the presence of solid potassium hydroxide and 18‐crown‐6 as a catalyst or cesium hydroxide monohydrate, without solvent.     

Arsen, Antimon

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