检索结果-南通市图书馆

Probing of the Isospin—Dependent Mean Field and Nucleon—Nucleon Cross Section in a Medium by Nucleon Emissions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2003年第5期20卷 643-646页

作者： liujian-Ye XINGYong-Zhong GUOWen-jun InstituteofTheoryofModernPhysics TianshuiNormalUniversityTianshui741000 InstituteofModernPhysics ChineseAcademyofSciencesPOBox31Lanzhou730000

We study the isospin effects of the mean field and two-body collision on the nucleon emissions at the intermediate energy heavy-ion collisions by using an isospin-dependent transport theory. The calculated results show that the nucleon emission number Nn depends sensitively on the isospin effect of nucleon-nucleon cross section and weakly on the isospin-dependent mean field for neutron-poor system in higher beam energy region. In particular, the correlation between the medium correction of two-body collision and the momentum-dependent interaction enhances the dependence of nucleon emission number Nn on the isospin effect of nucleon-nucleon cross section. On the contrary, the ratio of the neutron-proton ratio of the gas phase to the neutron-proton ratio of the liquid phase, i.e., the degree of isospin fractionation (N/Z)gasb/(N/Z)liqb depends sensitively on the isospin-dependent mean field and weakly on the isospin effect of two-body collision for neutron-rich system in the lower beam energy region. In this case, Nn and (N/Z)gasb/(N/Z)liqb are the probes for extracting the information about the isospin-dependent nucleon-nucleon cross section in the medium and the isospin-dependent mean field, respectively.

关键词： Neutrons

Effects of R-parity Violation on the Charged Higgs Boson Decays

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第5期43卷 873-878页

作者： SONGYi-Ping LIChong-Sheng LIQiang liujian-jun DepartmentofPhysics PekingUniversityBeijing100871China

We calculate one-loop R-parity-violating coupling corrections to theprocesses H~- → τv_τ and H~- → bt. We find that the corrections to the H~- → τv_τ decay modeare generally about 0.1%, and can be negligible. B... 详细信息

关键词： radiative correction charged Higgs decay R-parity violating supersymmetry

Studies on Nematic Liquid Crystal Using Spin Wave Theory

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2004年第3X期42卷 453-458页

作者： liujian-jun LIUXiao-Jing SHENMan YANGGuo-Chen CollegeofPhysics HebeiNormalUniversityShijiazhuang050016China InstituteofPhysics HebeiUniversityofTechnologyTianjin300130China

A spin wave theory is proposed to study nematic liquid crystals. Since the orientation of the molecularlong axis and the angular momentum of the molecule rotating around its long axis have the same direction, operatorscan be introduced to research the nematic liquid crystal. By transforming the intermolecular interaction potential,the Hamiltonian of the system has the same form as that of the ferromagnetic substance. The relation of the orderparameters to the reduced temperature can be obtained. It is in good agreement with the experimental results in thelow temperature region. In the high temperature region close to the transition point, by using the Hamiltonian, thetransition point can be obtained, which is near to the Maier-Saupe's result.

关键词：向列相液晶自旋波角动量哈密顿量临界点顺序参数

Targeting cholesterol trafficking to mitigate axonal degeneration in hereditary spastic paraplegia

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第5期20卷 1397-1398页

作者： Zhenyu Chen Xue-jun Li Department of Biomedical Sciences University of Illinois College of Medicine RockfordRockfordILUSA Department of Bioengineering University of Illinois at ChicagoChicagoILUSA

Axonal degeneration underlies many debilitating diseases including hereditary spastic paraplegia(HSP),a genetically and clinically diverse group of disorders characterized by spasticity and weakness of the lower *** is one significant cause of chronic neurodisability due to the lack of effective treatments and a wide range of onset ages from early childhood to 70 years.

关键词： degeneration diseases hereditary

Influence of Rare Earth on Property of Low Chromium Semi-Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2003年第3期10卷 50-53页

作者： liujian-hua XIEDan-yang LIChang-sheng SHAOLi ZHANGRui-jun YanshanUniversity Qinhuangdao066004China JiangsuUniversity Zhenjiang212013China HebeiNormalCollege Shijiazhuang050012China

The influence of rare earth( RE) content on mechanical properties and abrasion resistance of low chromium semi-steel was studied by means of metallographic examination,scanning electron microscopic examination and mechanical property test. The experiment results show that RE can improve the comprehensive properties,especially in combination with proper heat treatment. The optimum properties of low chromium semi-steel modified by RE of 0. 25 % could be obtained by normalization at 950 ℃ for 3 h. The main reason is the change in morphology and distribution of eutectic carbide and the precipitation of granular carbides.

关键词： rare earth low chromium semi-steel eutectic carbide precipitation granular carbide

Microstructure and Property of High Carbonic-Chromium Cast Steel with Different Hot Deformation Ratio

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2004年第1期11卷 37-41页

作者： XUTao WANGJiu-liang ZHANGRun-jun CHAOGuo-hua liujian-hua DaqingPetroleumInstitute Daqing163318China YanshanUniversity Qinhuangdao066004China KeyLaboratoryofMetastableMaterialsScienceandTechnology Qinhuangdao066004China

The microstructure and properties of high carbonic-chromium cast steel subjected to different hot deformation ratios were *** experimental results show that the microstructure and properties of high carbonic-chromium cast steel are obviously improved after hot deformation,and the best mechanical properties of the cast steel can be obtained under hot deformation ratio of 40 %-50 %,which leads to the morphology change of eutectic carbide and the precipitation of granular carbides.

关键词： high carbonic-chromium cast steel hot deformation ratio microstructure mechan-ical property

Study of Ratio of Proton Momentum Distributions with a Chiral Quark Model

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2005年第5期43卷 867-872页

作者： liujian DONGYu-Bing InstituteofHighEnergyPhysics theChineseAcademyofSciencesP.O.Box918（4）Beijing100049China

The ratio between the anomalous magnetic moments of proton and neutron has recently been suggested to be connected to the ratio of proton momentum fractions carried by the valence quarks inside it. This moment fraction ratio is respectively evaluated by using constituent quark model and chiral quark model in order to check meson cloud effect. Our results show that the meson cloud effect is remarkable to the ratio of the proton momentum fractions, and therefore, this ratiois a sensitive test for the meson cloud effect as well as for the SU(6) symmetry breaking effect.

关键词： ratio of proton momentum distribution anomalous magnetic moments constituent quark model chiral quark model

Total Nuclear Reaction Cross Section Induced by Halo Nuclei and Stable Nuclei

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2003年第5X期40卷 577-584页

作者： GUOWen-jun JIANGHuan-Qing liujian-Ye ZUOWei RENZhong-Zhou LEEXi-Guo CenterofTheoreticalNuclearPhysics NationalLaboratoryofHeavyIonAcceleratorLanzhou730000China InstituteofHighEnergyPhysics theChineseAcademyofSciencesBeijing100039China InstituteofModernPhysics theChineseAcademyofSciencesLanzhou730000China PhysicsDepartment NanjingUniversityNanjing210008China

We develop a method for calculation of the total reaction cross sections induced by the halo nuclei and stable nuclei. This approach is based on the Glauber theory, which is valid for nuclear reactions at high energies. It is extended for nuclear reactions at low energies and intermediate energies by including both the quantum correction and Coulomb correction under the assumption of the effective nuclear density distribution. The calculated results of the total reaction cross section induced by stable nuclei agree well with 30 experimental data within 10 percent *** comparison between the numerical results and 20 experimental data for the total nuclear reaction cross section induced by the neutron halo nuclei and the proton halo nuclei indicates a satisfactory agreement after considering the halo structure of these nuclei, which implies quite digerent mean fields for the nuclear reactions induced by halo nuclei and stable nuclei. The halo nucleon distributions and the root-mean-square radii of these nuclei can be extracted from the above comparison based on the improved Glauber model, which indicates clearly the halo structures of these nuclei. Especially,it is clear to see that the medium correction of the nucleon-nucleon collision has little effect on the total reaction cross sections, induced by the halo nuclei due to the very weak binding and the very extended density distribution.

关键词：原子核反应截面原子晕核原子核物理学量子修正稳定原子核

Improvement of Renormalization Group for Barenblatt Equation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2004年第2X期42卷 290-294页

作者： TUTao CHENGGeng liujian-Wei CenterforAdvancedStudy TsinghuaUniversityBeijing100084China CCAST(WorldLaboratory) P.O.Box8730Beijing100080China DepartmentofModernPhysics UniversityofScienceandTechnologyofChinaHefei230026China

We construct a Hartree-Fock (self-consistent)-like algorithm with renormalization group (RG) approach to calculate the anomalous dimension in a nonlinear diffusion equation. We find that our result improves the origin... 详细信息

关键词：重正化群非线性散射迭代近似相位转变散射系数海维赛德函数