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101.
Nazakat Ullah 《Pramana》1994,42(6):491-494
The distribution of quarks in light nuclei is given using the quark cluster wave function. An analytic expression for the
nucleus4He is obtained. The distribution so obtained is compared with the one obtained using a different theoretical formulation called
mapping. 相似文献
102.
We present a consistent theory of continua with defect distribution including the density of rotation nuclei. The elastic and self-fields of stresses and strains become asymmetric; the tensor of incompatibility also becomes asymmetric. We derive the dislocation–stress relations and the equations of motion related to the momentum and moment of momentum. Some applications important for earthquake engineering are presented. 相似文献
103.
60年前,里卡多·贾科尼团队用探空火箭首次探测到了来自太阳系以外的X射线辐射,从此打开了人类探索宇宙的一个全新的窗口。与我们所熟悉的可见光天空不同,在“看不见”的X射线宇宙,明亮的发光天体涵盖了黑洞、中子星、白矮星等致密天体,星系团和星系中弥漫的大量不可见的高温气体,以及各种剧烈的灾变事件。它们代表着宇宙中最为奇特的天体和极端的物理条件,如极强引力场、极强磁场和极高温。文章重点介绍最有代表性的X射线源,包括中子星和黑洞X射线双星、超大质量黑洞和活动星系核、星系团,以及伽马暴、超新星和潮汐瓦解恒星事件等爆发天体。 相似文献
104.
对于20Ne核,在相同的核壳和单粒子能级下,将在壳模型,Democracticmapping(DM)和微观IBM方案下的计算能谱与实验值作了直接比较通过DM揭示出壳模型理论与微观IBM理论间的关系:至少在sd壳上,后者源于前者,又是完成前者计算的一条好途径与一个好近似. 相似文献
105.
丰中子核以及重核熔合机制的研究以及中能重离子碰撞中多重碎裂的研究都迫切需要一个统一的、自洽的微观动力学模型.经过对量子分子动力学模型进行根本的改进,发展了一个新的、适用于低能以及中能重离子反应的统一描述的微观动力学模型.改进的量子分子动力学(ImQMD)模型能够将整个熔合反应过程中的动力学效应、同位旋效应以及弹靶质量不对称效应等比较全面地、自洽地考虑进来,从而给熔合反应的研究提供了一个新的途径.ImQMD模型能够很好地再现一系列核的基态性质以及10多个熔合反应的激发函数(包括丰中子核熔合体系以及实验最新测量的132Sn+64Ni熔合体系).此外还运用该模型初步探索了重核熔合过程中复合体系的寿命与体系的入射能量、体系大小以及体系的中子质子比的依赖关系. We have developed a new microscopic dynamical model called improved quantum molecular dynamical model (ImQMD). This model can describe the fusion process at energies near the Coulomb barrier as well as the multifragmentation process at intermediate energies in heavy-ion collision (HIC) uniformly. By using this model, fusion cross sections (including some of neutron-rich nuclei reactions and that of newly measured~(132)Sn+~(64)Ni fusion reaction) of tens reactions can be reproduced remarkably well. In fusi... 相似文献
106.
相对论自洽角动量投影壳模型是最近发展出来的一个自洽模型, 它对于不同核区具有稳定的参数, 能够很好地描述已知和未知具有稳定形变的各种原子核的性质。 计算了若干包括稳定核素、 极端核素和超重核素, 并把计算结果与现有的实验数据进行了比较。 相似文献
107.
T. Hirano 《The European Physical Journal A - Hadrons and Nuclei》2006,29(1):19-22
We can establish a new picture, the perfect fluid sQGP core and the dissipative hadronic corona, of the space-time evolution
of produced matter in relativistic heavy-ion collisions at RHIC. It is also shown that the picture works well also in the
forward rapidity region through an analysis based on a new class of the hydro-kinetic model and that this is a manifestation
of the rapid increase of the entropy density in the vicinity of QCD critical temperature, namely, deconfinement. 相似文献
108.
R. I. Petrova V. P. Perelygin A. B. Akopova M. M. Gogorjan 《Radiation measurements》1995,25(1-4):329-330
The investigation of the track etching velocity dependence for nuclei with Z50 on pH of the etching solution in the olivine crystals from Marjalahti and Eagle Station meteorites, containing galactic cosmic-ray nuclear tracks and also the crystals from Marjalahti meteorite, calibrated at the UNILAC (GSI, Darmstadt) with 14.17 MeV/N 208Pb nuclei, were performed.
The pH of the etching solution were changed from 7.8 to 9.4. It is shown that the optimal track etch condition were realised at pH of etching solution in the interval from 8.4 to 8.8.
The results of the Galactic cosmic-ray nuclei tracks with Z83 revealed in olivine crystals are presented. They were additionally irradiated at 90% to the surface with accelerated 14 MeV/N 132Xe nuclei. 相似文献
109.
The generation of pure quadrupolar stimulated-echo spectra is successfully demonstrated for the spin-
probe 9Be in a single crystal of triglycine fluoberyllate. This solid exhibits a paraelectric-to-ferroelectric phase transition. From experiments carried out for various mixing times no indications for a slow soft mode could be detected in this crystal. Then ion conducting lithium metal phosphates were studied using 7Li, another spin-
probe which allows for a non-selective excitation of the entire NMR spectrum. In the indium and the scandium phosphates ultra-slow Li hopping processes could be detected directly via the stimulated-echo technique in a time range of up to four orders of magnitude. Due to the relatively large gyromagnetic ratio and thus strong dipolar interactions of 7Li no pure quadrupolar echoes could be generated. However, from a variation of the evolution times the quadrupolar effects could be separated from the dipolar ones. Finally, the differences in the ion hopping times of lithium indium phosphate and of lithium scandium phosphate are briefly discussed. 相似文献
110.
用非线性相对论平均场对两对镜像核13N-13C 和15N-15O进行了研究. 发现无论在基态还是激发态, 用两套参数所得的结合能都跟实验值很接近. 计算结果显示13N的第一激发态(2s1/2)和第三激发态(1d5/2)各存在一个非束缚的质子晕, 而13C的第三激发态(1d5/2)存在一个弱束缚的中子皮. 另外研究表明, 在另一对镜像核15N-15O的第二激发态(2s1/2)和第一激发态(2s1/2)分别存在一个中子晕和质子皮. Properties of two pairs of mirror nuclei 13N-13C and15N-15O are investigated by using the nonlinear relativistic mean field theory. It is found that all the calculated binding energies with two different parameter sets are very close to the experimental ones for both the ground states and the excited states. The calculations show that the first excited state (2s1/2) and the third excited state (1d5/2) in 13N are both unbound resonances with proton halo structure, whereas the third excited state (1d5/2) in 13C is weakly bound with a neutron skin. It is also predicted that there has a proton halo in the second excited state (2s1/2) of 15N as well as a neutron skin in the first excited state (2s1/2) of 15O. 相似文献