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1.
The Langevin equation is used to simulate the fission process of ^112Sn ^112Sn and ^116Sn ^116Sn. The mass distribution of the fission fragments are given by assuming the process of symmetric fission or asymmetric fission with the Gaussian probability sampling. The isoscaling behaviour has been observed from the analysis of fission fragments of both the reactions, and the isoscaling parameter α seems to be sensitive to the width of fission probability and the beam energy. 相似文献
2.
方德清 Yamaguchi T. 郑涛 Ozawa A. Chiba M. Kanungo R. Kato T. Morimoto K. Ohnishi T. Suda T. Yamaguchi Y. Yoshida A. Yoshida K. Tanihata I.< 《中国物理 C》2004,28(Z1)
实验测量了83A MeV 14,15C的核反应总截面(σR)及15C产生14,15C和14C产生13C的动量分布(P//). 分析得到了15C产生14C和13C的动量分布半高宽(FWHM)分别为71±9MeV/c和223±28MeV/c, 而14C产生13C的FWHM为195±21MeV/c. 从15C和14C产生13C的FWHM与Goldhaber模型的预言基本一致. 而15C产生14C的FWHM却要比该模型计算小得多. 同时观测到15C的σR比相邻核有反常增加. 在Glauber模型框架中, 对实验测得的P//和σR进行了探讨. P//和σR的分析结果同时显示15C的最后一个中主要处于s1/2态, 具有中子晕结构. 相似文献
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用脉冲吸附和程序升温脱附(TPD)对α-Fe_2O_3,ZnFe_2O_4和ZnCrFeO_4进行了正丁烯异构体的吸附和反应性能的考察。结果表明,在室温下,三种正丁烯在α-Fe_2O_3上几乎不发生表面反应,而在ZnFe_2O_4,ZnCrFeO_4上则有不同程度的双键位移和选择氧化。多次脉冲吸附表明,第二次脉冲尾气中的丁二烯含量远大于第一次脉冲。各丁烯在三种氧化物上吸附后的TPD谱可分为以丁烯和丁二烯为脱附物的低温区(<200℃)与脱附物全部为CO_2的高温区(200~600℃)。丁烯-1在α-Fe_2O_3上较易热脱附,在其余两种氧化物表面上则强烈滞留,需经多次TPD才能脱净。还讨论了选择氧化部位和全氧化部位在这类氧化物表面上的可能形态。 相似文献
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A sequential decay model is used to study isoscaling, i.e. the factorization of the isotope ratios from sources of different isospins and sizes over a broad range of excitation energies, into fugacity terms of proton and neutron number, R21(N, Z) = Y2( N, Z)/Y1( N, Z) = Cexp(αN -βZ). It is found that the isoscaling parameters α and β have a strong dependence on the isospin difference of equilibrated source and excitation energy, no significant influence of the source size on α andβ has been observed. It is found that α and β decrease with the excitation energy and are linear functions of 1/T and △(Z/A)2 or△(N/A)2 of the sources. Symmetry energy coefticient Gsym is constrained from the relationship of a and source △(Z/A)2, /3 and source △(N/A)2. 相似文献
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This paper studies the Nevanlinna second fundamental theorem,and the extra term εT(r,f) in the n-small-functions theorem of Steinmetz is removed. 相似文献
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<正> Su has recently established the projective theory of space curvesby a purely geometrical method and has shown among other thingsthat the projective invariants of a curve can simply be expressed by cer-tain double ratios.In my former paper I have interpreted the curvatureform by the Von Staudt's double ratios of the tangent of the space curveC at a point infinitely near an ordinary point P with respect to unda-mental tetrahedron of Sannia at P. 相似文献
10.
The correlation between neutron-to-proton yield ratio (Rnp) and neutron skin thickness (δnp) in neutron-rich projectile induced reactions is investigated within the framework of the Isospin-Dependent Quantum Molecular Dynamics (IQMD) model. The density distribution of the Droplet model is embedded in the initialization of the neutron and proton densities in the present IQMD model. By adjusting the diffuseness parameter of neutron density in the Droplet model for the projectile, the relationship between the neutron skin thickness and the corresponding Rnp is obtained. The results show strong linear correlation between Rnp and δnp for neutron-rich Ca and Ni isotopes. It is suggested that Rnp may be used as an experimental observable to extract δnp for neutron-rich nuclei, which is very interesting in the study of the nuclear structure of exotic nuclei, the equation of state (EOS) of asymmetric nuclear matter and neutron-rich matter in astrophysics, etc. 相似文献