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891.
Production and properties of φ-meson under the extreme hot dense matter which is formed in Au + Au collisions at RHIC energy have been briefly reviewed.The issues are focused on transverse momentum (p T ) spectra of φ,elliptic flow of φ,nuclear modification factor of φ,the ratio of Ω(p T )/φ(p T ) versus p T,the ratio of Ω(p T /3)/φ(p T /2) versus p T /n q,spin alignment of φ and the enhancement of φ etc.These observables give the significant information of the strange quark dynamics in hot dense matter under the extreme condition. 相似文献
892.
The cross sections of the fragments produced in the projectile fragmentation reactions of the even calcium isotopes from A=36 to A=52 are calculated using the statistical abrasion ablation model.The neutron skin thickness are studied by investigating the fragments isotopic cross section distributions.The neutron-skin thicknesses of the calcium isotopes have a good linear correlation to the peak positions of their fragment isotopic cross section distributions.The correlation between the neutron skin thickness and the neutron density distributions of 48 Ca is investigated by introducing a parameter to adjust the diffuseness parameter in the fermi-type density distribution. 相似文献
893.
By using the rigorous spectral representation of relativistic random phase approximation, the low-lying excitation of finite nuclei and its longitudinal response function for quasielastic electron scattering are calculated in the σ-ω model of quantum hadrodynamics. It is shown that the reproduction of the correct order of the 1- and 3- excitation states of 16O is due to the contribution of the exchange vertex. There is no significant influence of the retardation effect on the low-lying excitation states. In contrast, the retardation effect plays an important role in the electron scattering process of nuclei. The theoretical longitudinal responses of 12C and 40Ca, including the contributions of the exchange vertex and the retardation effect, are suppressed and reproduce the experimental data better than the results excluding them. 相似文献
894.
Inhomogenous Dislocation Nucleation Based on Atom Potential in Hexagonal Noncentrosymmetric Crystal Sheet
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By introducing internal degree, the deformation of hexagonal noncentrosymmetric crystal sheet can be described by the revised Cauchy-Born rule based on atomic potential. The instability criterion is deduced to investigate the inhomogeneous dislocation nucleation behavior of the crystal sheet under simple loading. The anisotropic characters of dislocation nucleation under uniaxial tension are studied by using the continuum method associated with the instability criterion. The results show a strong relationship between yield stress and crystal sheet chirality. The results also indicate that the instability criterion has sufficient ability to capture the dislocation nucleation site and expansion. To observe the internal dislocation phenomenon, the prediction of the dislocation nucleation site and expansion domain is illustrated by MD simulations. The developed method is another way to explain the dislocation nucleation phenomenon. 相似文献
895.
Lifetimes of high spin states in 129Cs axe measured using the Doppler shift attenuation method. The high spin states of 129 Cs axe populated following the fusion evaporation reaction 124 Sn(UB, 6n)129 Cs at a beam energy of 65 MeV. The reduced transition probabilities B(E2) and the transition quadrupole moments Qt in the negativeand positive-paxity bands are deduced. The experimental results indicate that the Qt values of the negative parity band are smaller than those of the positive parity bands, probably due to different γ-deformation driving effects of different proton orbitals. The Qt values exhibit a considerable increase near the band crossing region in these bands. This behavior demonstrates that nuclear shape changing results from the neutron or proton alignments. The signature splitting of the πh11/2 and πg7/2 bands shows the opposite changing trend after backbending due to the h11~2 neutron and h11/2 proton alignments, respectively. 相似文献
896.
We reinvestigate the collective effects of the retardation as well as the bending on the Coulomb excitation cross sections and also on the B(E2) strengths of some neutron-rich isotopes using the intermediate energy Coulomb excitation theory. It is found that the B(E2) strengths extracted from the experimental Coulomb excitation cross section data get suppressed approximately by 6%. Furthermore, the obtained B(E2) strengths in the energy range 30-100 MeV/A are found to be in better agreement with the corresponding values known from other sources, than those obtained by using the recoil-corrected relativistic Coulomb excitation theory. 相似文献
897.
898.
899.
随着电路复杂性的增加,越来越多的设计者开始采用拥有知识产权的、设计良好的功能模块来加快系统开发.因此,需要相应的技术手段保护这些功能模块不被非法复制、篡改或窃取.针对FPGA开发中的知识产权保护问题,提出一种结合EDA软件和FPGA的IP(Intellectual Proterty)核保护方法,有效的防止IP核被窃取,以及防止最终在FPGA上实现设计的非法复制. 相似文献
900.
郑玉山 《微电子学与计算机》2009,26(3)
关联分析和分类分析是数据挖掘的关键技术,但传统算法对入侵检测数据进行处理时有很多的不足,使用加权关联分析和核机器分类算法构造混合型入侵检测系统,设计后的系统框架分为检测客户端和检测服务端,检测客户端主要是对数据的预处理和生成检测模型;检测服务端主要是判断检测模型,进行入侵数据的二次挖掘.结果说明,该系统具有良好的入侵数据分类效果. 相似文献