Ground-State Properties of Ca Isotopes and the Density Dependence of the Symmetry Energy

A relativistic mean field model is used to study the ground-state properties of neutron-rich nuclei in Ca isotopes. An additional isoscalar and isovector nonlinear coupling has been introduced in the relativistic mean field model, which could soften the symmetry energy, while keep the agreement with the experimental data. The sensitivity of proton and neutron density distributions and single particle states in Ca isotopes to the additional isoscalarisovector nonlinear coupling term is investigated. We found that the binding energies, the density distributions of single particle levels are strongly correlated with the density dependence of the symmetric energy in nuclear matter.     

Group Foliation Method and Functional Separation of Variables to Nonlinear Diffusion Equations

Generalized functional separation of variables to nonlinear diffusion equations is studied in terms of the extended group foliation method. A complete classification for the nonlinear diffusion equation with source term which admits functional separable solutions is presented.     

利用快分子离子与固体的相互作用对H2+,HD+和D+2结构的研究

利用快分子离子与固体的相互作用,依靠一套高分辨装置,测量了H2+,HD+和D2+的结构,得到其核间距分别为1.19±0.003 nm、1.25±0.003 nm和1.32±0.003 nm.通过对比,证实了分子离子结构中同位素效应的存在,分析了实验值和理论值存在差别的原因,讨论了实验结果中同位素效应产生的缘由.     

氢同位素球形靶丸在其相应高能离子轰击下的消融

本文采用跨音速中性气体屏蔽模型,得到了氢同位素球形靶丸在其相应高能离子轰击下的消融率G_(is)及其定标律,s可为氢或氘。计算表明,当离子与电子的未扰态能量E_(0s)/E_(0e)~2≥1.5时,G_(is)/G_(es)≥20％,G_(es)为靶丸在等离子体电子轰击下的消融率。因此,当聚变实验有中性粒子束注入加热时,需考虑高能离子轰击对靶丸消融的影响。这也为此情况下靶丸消融强化提供了一种解释。     

Lifetimes of Excited Levels in ^131Ce

The fusion-evaporation reaction ^116Sn (^19F, p3n)^131 Ce at projectile energy of 95 MeV is used to populate high spin states in ^131Ce. The de-exciting γ-rays are detected in γ-γ coincidence measurement with Compton-suppressed BGO-HPGe detectors. Level lifetimes of ^131 Ce were determined by using the Doppler shift attenuation method.The experimental results indicate that collectivity of ^131 Ce is reduced relative to that of ^130Ce and it follows that deformation decreases with increase of the neutron number on the basis of systematic comparison of transition quadrupole moments for the light cerium isotopes.     

加速器质谱技术及其在测定36Cl中的应用

 加速器质谱技术（AMS）又称超灵敏质谱技术,是在80年代发展起来的一种超微量核分析方法。它对有些同位素分析的丰度灵敏度达到10（-16）,或者说可探测到10⁴个原子,比普通质谱计的灵敏度高出8-9个数量级。     

Sn偶同位素准转动带的微观研究

在相互作用玻色子模型微观基础的研究方面,曾提出过以玻色子展开和修正的Jancovici-Schiff代换为基础的理论方案.本文反方案扩充到有中子、质子和质子空穴三种玻色子的情况,用它研究Sn偶同位素由质子2p-2h激发组态混入形成的准转动带.计算结果与实验能谱作了比较并讨论了组态混合的一些特性.     

探测地下水参数的同位素示踪仪及其应用

本文简述了同位素示踪技术测定地下水参数的基本原理和方法．应用碘－１３１作为示踪剂，在一口井中探测地下水的流向、流速、垂向流，监测坝基渗漏，以及研究地下水的补给等．介绍了一种探测地下水参数的同位素示踪仪，其测量深度大于３００ｍ，流向测定误差小于±３％，流速测定范围为０．０１－１００ｍ／ｄ．     

在线同位素分离器中空阴极靶离子源

本文描述兰州中国科学院近代物理研究所的在线同位素分离器中空气阴极靶离子源的设计原理、结构和特性。对Ar和Xe的调试结果。分离器的分辨本领达到700-1200。满足高分辨的要求。