中国水华蓝藻的新记录属——拟浮丝藻属(Planktothricoides)

在近年来对水华蓝藻的调查中,确定了我国一水华蓝藻新记录属——拟浮丝藻属Planktothricoides(WoIoszyńska) Suda et Watanabe 2002。文中对该属及该属一个新记录种的主要形态学特征进行了描述,并对其相近属浮丝藻属Planktothrix进行了形态学比较研究。

Pion Production in Heavy-ion Collisions in the 1 A GeV region

Within the framework of the improved isospin dependent quantum molecular dynamics (ImIQMD) model, the pion emission in heavy-ion collisions in the region 1AGeV is investigated systematically, in which the pion is considered to be mainly produced by the decay of resonances ∆(1232) and N∗(1440). The in-medium dependence and Coulomb effects of the pion production are included in the calculation. Total pion multiplicity and π−/π+ yields are calculated for the reaction 197Au+197Au in central collisions for selected Skyrme parameters SkP, SLy6,Ska, SIII and compared them with the measured data by the FOPI collaboration.

Pion Production in Heavy-Ion Collisions in the 1 A GeV Region

Within the framework of the improved isospin dependent quantum molecular dynamics (ImIQMD) model, pion emission in heavy-ion collisions in the region 1 A GeV is investigated systematically, in which the pion is considered to be mainly produced by the decay of resonances Delta(1232) and N*(1440). The in-medium dependence and Coulomb effects of pion production are included in the calculation. Total pion multiplicity and pi(-)/pi(+) yields are calculated for the reaction Au-197+(197) Au in central collisions for selected Skyrme parameters SkP, SLy6, Ska, SIII and compared with the measured data of the FOPI collaboration.

Probing high-density behavior of symmetry energy from pion emission in heavy-ion collisions

Within the framework of the improved isospin dependent quantum molecular dynamics (ImIQMD) model, the emission of pion in heavy-ion collisions in the region 1 A GeV as a probe of nuclear symmetry energy at supra-saturation densities is investigated systematically, in which the pion is considered to be mainly produced by the decay of resonances Delta(1232) and N*(1440). The total pion multiplicities and the pi(-)/pi(+) yields are calculated for selected Skyrme parameters SkP, SLy6. Ska and SIB, and also for the cases of different stiffness of symmetry energy with the parameter SLy6. Preliminary results compared with the measured data by the FOPI Collaboration favor a hard symmetry energy of the potential term proportional to (rho/rho(0))(gamma s) with gamma(s) = 2. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.

Dynamics of pion production in heavy-ion collisions around 1A GeV energies

Within the framework of the improved isospin-dependent quantum molecular dynamics model, the dynamics of pion emission in heavy-ion collisions in the region of 1A GeV energies as a probe of nuclear symmetry energy at suprasaturation densities is investigated systematically. The total pion multiplicities and the pi(-)/pi(+) yields are calculated for selected Skyrme parameters SkP, SLy6, Ska, and SIII and also for the cases of different stiffness of symmetry energy with the parameter SLy6. The influence of Coulomb potential, symmetry energy, and in-medium pion potential on the pion production is investigated and compared to each other by analyzing the distributions of transverse momentum and longitudinal rapidity and also the excitation functions of the total pion and the pi(-)/pi(+) ratio. The directed flow, elliptic flow, and polar-angle distributions are calculated for the cases of different collision centralities and also the various stiffnesses of the symmetry energies. A comparison of the calculations with the available experimental data is performed.

PROBING THE SYMMETRY ENERGY AT SUPRA-SATURATION DENSITIES FROM PION EMISSION IN HEAVY-ION COLLISIONS

Within the framework of the improved isospin dependent quantum molecular dynamics (ImIQMD) model, the emission of pion in heavy-ion collisions in the region 1 A GeV as a probe of nuclear symmetry energy at supra-saturation densities is investigated systematically, in which the pion is considered to be mainly produced by the decay of resonances Delta(1232) and N*(1440). The pi(-)/pi(+) yields are calculated for selected Skyrme parameters SkP, SLy6, Ska and SIII, and also for the cases of different stiffness of symmetry energy with the parameter SLy6. Preliminary results compared with the measured data by the FOPI collaboration favor a hard symmetry energy of the potential term proportional to (rho/rho(0))(gamma s) with gamma(s) = 2.

中能重离子碰撞中的能量储存

本文用非相对论的BUU理论模型，系统地讨论了能量储存同入射道效应（入射能量，碰撞参数，碰撞系统）之间的关系，即讨论了不同碰撞参数下激发能的变化情况，讨论了对称系统，极不对称系统对激发能量的依赖关系及不同能量下激发能的大小。从而得到动力学效应对能量的影响。用扩展的Skyrme相互作用得到的动量密度相关的平均场状态方程，讨论了由压缩系数，有效质量来标志的核物质性质对能量储存的影响。计算了压缩系数接近，有效质量差别较大的SKA，SKM对能量储存的关系。借此来讨论动量相关性对能量储存的敏感性；同时用有效质量一样压缩系数差别较大的SGOI，SGOII来讨论核物质的压缩对能量储存是否有影响。用此理论计算为实验上得到更高的热核温度提供信息