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1.
Based on the Weinberg-Salam theory,the pair neutrino energy loss rates for nuclei 56Fe are canvassed for the wide range of density and temperature.The results of ours (QLJ) are compared with those of Beaudet G,Petrosian V and Salpeter E.E's (QBPS),and it shows that the pair neutrino energy loss rates of QBPS are always larger than QLJ .The QBPS is 12.57%,12.86%,14.99%,19.80% times higher than QLJ corresponding to the temperature T9=0.385,1.0,5.0,10,respectively. 相似文献
2.
Based on the Weinberg-Salam theory, the pair neutrino energy loss rates for nuclei 56Fe are can- vassed for the wide range of density and temperature. The results of ours (QLJ) are compared with those of Beaudet G, Petrosian V and Salpeter E. E's (QBPS), and it shows that the pair neutrino energy loss rates of QBPS are always larger than QLJ .The QBPS is 12.57%, 12.86%, 14.99%, 19.80% times higher than QLJ corresponding to the temperature T9=0.385, 1.0, 5.0, 10, respectively. 相似文献
3.
LIU Jing-Jing 《中国物理C(英文版)》2009,33(10)
Based on the Weinberg-Salam theory, the plasma neutrino energy loss rates of vector and axialvector contributions are studied.A ratable factor of the rates from the axial-vector current relative to those of the total neutrino energy loss rates is accurately calculated.The results show that the ratable factor will reach a maximum of 0.95 or even more at relatively higher temperature and lower density (such as P/μe< 10~7 g/cm~3).Thus the rates of the axial-vector contribution cannot be neglected.On the other hand, the rates of the axialvector contribution are on the order of~0.01% of the total vector contribution, which is in good agreement with Itoh's at relatively high density (such as p/μe>10~7 g/cm~3) and a temperature of T≤10~(11) K. 相似文献
4.
Based on the Weinberg-Salam theory, the plasma neutrino energy loss rates of vector and axialvector contributions are studied. A ratable factor of the rates from the axial-vector current relative to those of the total neutrino energy loss rates is accurately calculated. The results show that the ratable factor will reach a maximum of 0.95 or even more at relatively higher temperature and lower density (such as p/μe 〈 10^7 g/cm^3). Thus the rates of the axial-vector contribution cannot be neglected. On the other hand, the rates of the axialvector contribution are on the order of ~0.01% of the total vector contribution, which is in good agreement with Itoh's at relatively high density (such as p/μe 〉 10^7 g/cm^3) and a temperature of T ≤ 10^11 K. 相似文献
5.
LIU Jing-Jing 《中国物理C(英文版)》2009,33(1):15-19
Based on the Weinberg-Salam theory,the competition of the Neutrino Energy Loss (NEL) rates due to the pair,photo- and plasma process are canvassed.The ratio factor C1,C2 and C3 which correspond the different contributions of the pair,photo- and plasma neutrino process to those of the total NEL rates are accurately taken into account.The ratio factors are very sensitive to the temperature and density.The ratio factor C2 always is lower than the ratio factor C1 and C3.The pair NEL process is the dominant contribution before the crossed point O(C1=C3=0.45) and the plasma NEL process will be the main dominant contribution after the crossed point O.With increasing temperature,the crossed point O will move to the direction of higher density. 相似文献
6.
Based on the Weinberg-Salam theory, the competition of the Neutrino Energy Loss (NEL) rates due to the pair, photo-and plasma process are canvassed. The ratio factor C1, C2 and C3 which correspond the different contributions of the pair, photo-and plasma neutrino process to those of the total NEL rates are accurately taken into account. The ratio factors are very sensitive to the temperature and density. The ratio factor C2 always is lower than the ratio factor C1 and C3. The pair NEL process is the dominant contribution before the crossed point 0(C1 = C3 = 0.45) and the plasma NEL process will be the main dominant contribution after the crossed point O. With increasing temperature, the crossed point O will move to the direction of higher density. 相似文献
7.
Neutrino Energy Loss by Electron Capture on Nucleus ^56Mn, ^56Fe, ^56Co and ^56Ni in Strong Electron Screening
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Based on the p-f shell model, the neutrino energy loss rates for nucleus ^56Mn, ^56Fe, ^56Co and ^56Ni in the electron capture process are canvassed in and not in a strong electron screening. The results show that the neutrino energy loss rates for ^56Mn, ^56Fe, ^56Co and ^56Ni decrease about 15%, 10%, 60% and i order of magnitude correspondingly at the temperature T9 = 15 and even debase 2 orders of magnitude at the temperature T9 = 1. 相似文献
8.
The interacting boson model with isospin (IBM-3) is applied to study the band structure and electromagnetic transition properties of the low-lying states in the cross-conjugate nuclei 44Ti and 52Fe. The isospin excitation states with T=0, 1 and 2 are identified and compared with available data. The E2 and M1 matrix elements for the low-lying states have been investigated. According to this study, the 23+ state is the lowest mixed symmetry state in the cross-conjugate nuclei 44Ti and 52Fe. The excitation energy of the second 02+ and 22+ states with T=0 in the nucleus 52Fe are identified. The agreement between the model calculations and data is reasonably good. 相似文献
9.
《Physics Reports》1987,156(3):111-146
Advances in the infrared and radio observational techniques in the last decade have led to a revolution in our understanding of the late stages of stellar evolution. Intermediate (1–8 M⊙) mass stars are found to be undergoing rapid mass loss in the form of a stellar wind during the asymptotic-giant-branch after the exhaustion of helium burning in the core. Significant fraction of the original stellar mass can be lost in short time scales of < 106 yr. The ejected mass constitutes the major component of matter returned by stars to the interstellar medium. Since such material has been heavily nuclear processed, they also represent the dominant mechanism of chemical enrichment of the Galaxy. The high rate of mass loss implies that the majority of Population I stars end their evolution as planetary nebulae and white dwarfs rather than superovae and neutron stars.In this review, we summarize recent observational methods in the determination of the mass loss rate and the associated physical parameters of the stellar wind. Since the observed mass loss rate greatly exceeds the nuclear burning rate, we also discuss the theoretical models on how such mass loss affects the asymptotic giant branch evolution. A scenario is presented on how red giants evolve into planetary nebulae, a process which has been very poorly understood until recently. Conjectures on how the current evolutionary “missing link” - the proto-planetary nebulae - could be identified are also considered. 相似文献
10.
LIU Jing-Jing 《中国物理C(英文版)》2013,37(8):085101-0851
Based on the theory of relativity in superstrong magnetic fields (SMFs), we have carried out an estimation on electron capture (EC) rates of nuclides 52,53,54,55,56Fe in the SMFs in magnetars. The rates of change of electronic fraction (RCEF) in the EC process are also discussed. The results show that the EC rates increase greatly and even exceeds by 4 orders of magnitude (e.g. 54Fe, 55Fe and 56Fe) in SMF. On the contrary, the RCEF decreases largely and even exceeds by 5 orders of magnitude in the SMF. 相似文献
11.
The yrast bands of 51,52,53Fe have been studied with a microscopical effective Hamiltonian derived from the charge-dependent Bonn NN potential. Calculations obtain satisfactory agreements with experimental data, reproducing the observed isomeric states. The possible origins of the isomers are discussed. 相似文献
12.
By means of using an isospin-dependent Boltzmann-Langevin equation which includes isospin-dependent symmetry energy, Coulomb energy, isospin-dependent nucleon-nucleon cross sections, Pauli blocking, and initialization, the radial expansion flow of reaction systems 40Ca+58Ni and 40Ca+58Fe at 53, 100, 150, and 200 MeV/u in the central collisions were studied. It has shown that the more neutron rich system exhibits smaller radial expansion flow. It was found that the neutron rich system had smaller threshold energy which may provide a new method to determine the isospin dependent nuclear equation of state from calculated result and linear fitting result. 相似文献
13.
Three-body exit channel in the reaction 12C+16O at 56MeV has been studied by using measurement of the coincidence between the two changed particles.The projected spectra of the coinsidence between the two α-particles shows that the channel α+24Mg is the main intermediate process of three-body exit channel α1+α2+20Ne in the reaction 12C+16O at 56MeV.The analysis of theoretical calculation showed that the sum of sequential decay and statistical break-up fit the experimental spectra satisfactorily. 相似文献
14.
LIU Jing-Jing KANG Xiao-Ping HE Zhong HUANG Huai-Ren SHI Huan-Yu HUANG Hong-Chao ZHONG Shan FENG Hao LI Chang-Wei 《中国物理C(英文版)》2011,35(3)
Gaussian modifications of the neutrino energy loss (NEL) by electron capture on the strongly screening nuclides 55Co and 56Ni are investigated. The results show that in strong electron screening (SES),the NEL rates decrease without modifying the Gamow-Teller (G-T) resonance transition. For instance, the NEL rates of 55Co and 56Ni decrease more than two and three orders of magnitude for ρ7 = 5.86, T9≤ 5,Ye = 0.47, △ = 6.3, respectively. In contrast, due to Gaussian modification, the NEL rates increase about two orders of magnitude in SES. Due to SES, the maximum values of the C-factor (in %) on NEL of 55Co, 56Ni are of the order of 99.80%, 99.56% at ρ7 = 5.86 Ye = 0.47 and 99.60%, 99.65% at ρ7 = 106 Ye = 0.43, respectively. 相似文献
15.
郑永男 周冬梅 袁大庆 M. Mihara K. Matsuta M. Fukuda T. Minamisono T. Suzuki 张锡珍 左翼 徐勇军 朱佳政 王志强 骆海龙 范平 朱升云 《中国物理 C》2008,32(Z2):174-176
The spin polarized β-emitting mirror nuclei 12B(Iπ=1+,T1/2=20.18 ms) and 12N(Iπ=1+,T1/2=11 ms) are produced by the low nuclear reactions 11B(d, p) 12B and 10B(3He,n) 12N and by selecting the projectile energy and the recoil angle. Their magnetic moments are measured by the β-NMR technique. The magnetic moments obtained after Knight shift correction are μ(12B)=1.001(17) μN and μ(12N)=0.4571(1) μN. The calculation using the existing shell model could not reproduce the measured magnetic moments for 12B and 12N simultaneously. 相似文献
16.
LI Er-Tao LI Zhi-Hong LI Yun-Ju YAN Sheng-Quan BAI Xi-Xiang GUOBing SU Jun WANG You-Bao WANG Bao-Xiang LIAN Gang ZENGSheng FANG Xiao ZHAO Wei-Juan LIU Wei-Ping 《中国物理快报》2009,26(7)
Angular distribution of the 12C(6He,7Li)11B transfer reaction is measured with a secondary 6He beam of 36.4MeV for the first time. The experimental angular distribution is well reproduced by the distorted-wave Born approximation (DWBA) calculation. The success of the present experiment shows that it is feasible to measure one-nucleon transfer reaction on a light nucleus target with the secondary beam facility of the HI-13 tandem accelerator at China Institute of Atomic Energy (CIAE), Beijing. 相似文献
17.
范凤英 郑涛 叶沿林 江栋兴 华辉 李智焕 葛愉成 李湘庆 楼建玲 史帆 吕林辉 曹中鑫 聂鹏煊 李奇特 宋玉收 卢飞 徐瑚珊 胡正国 王猛 张雪荧 李琛 陈若富 唐彬 徐治国 岳珂 张亚鹏 臧永东 章学恒 姚向武 陈金达 涂小林 张洁 武大鹏 白真 《中国物理快报》2009,26(8):74-77
Differential cross sections for the quasi-elastic scattering of^16 C at 47.5 MeV/nucleon from ^12 C target are measured.Coupled-channels calculations are carried out and the optical potential parameters are obtained by fitting the experimental angular distribution. 相似文献
18.
Gaussian modifications of the neutrino energy loss (NEL) by electron capture on the strongly screening nuclides 55Co and 56Ni are investigated. The results show that in strong electron screening (SES), the NEL rates decrease without modifying the Gamow-Teller (G-T) resonance transition. For instance, the NEL rates of 55Co and 56Ni decrease more than two and three orders of magnitude for ρ7=5.86, T9≤5, Ye=0.47, Δ=6.3, respectively. In contrast, due to Gaussian modification, the NEL rates increase about two orders of magnitude in SES. Due to SES, the maximum values of the C-factor (in %) on NEL of 55Co, 56Ni are of the order of 99.80%, 99.56% at ρ7=5.86 Ye=0.47 and 99.60%, 99.65% at ρ7=106 Ye=0.43, respectively. 相似文献
19.
Measurement of Angular Distributions for Elastic Scattering of 16O+94Zr and 16O+116Sn Reactions
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HU GuiQing ZHAO Kui JIANG Hua GUO JiYu FU ChangBo LU XiuQin LIANG Gang LI ZhiChang LI ShuYuan LIU JianCheng 《中国物理C(英文版)》2000,24(8):725-731
The angular distributions for elatic scattering of the two systems,16O+94Zr at energies 52,57,59,62,72,82 and 92 MeV and 16O+116Sn at energies 57,59,62,67,72,82 and 92 MeV have been measured.The scattered ions were datected by the Beijing Q3D magnetic spectrometer and its heavy ion focal plane detector.The optical model analysis of the data was made with the Coupled Channels code ECIS, and the optical potential parameters have been obtained by fitting the data.Within the limited data,the phenomenon of the ‘threshold anomaly’is observed. 相似文献
20.
Angular and Z Distributions of the Fragments at Forward and Intermediate Angles in the Reaction of 25MeV/u 40Ar+115In,58Ni,27Al
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WANG JinChuan ZHAN WenLong GUO ZhongYan XI HongFei LIU Hang ZHOU JianQun ZHAO YouXiong 《中国物理C(英文版)》2000,24(1):41-48
The angular & Z distributions of foe fragments emitted in the forward and intermediary angles are measured at the reaction of 25 MeV/u 40Ar+115In,58Ni,27Al. Their characteristics are investigated based on the model of Modified Qantum Molecular Dynamics (MQMD). Generally, the theoretical calculations are in good agreement with the experiment data. But in the forward angles the yield of the fragments is underestimated by MQMD model while in the case of the intermediate angle region, the calculation is higher than the experiment data in some degree for the fragments whose charge numbers are in the vicinity of the proiectile. The angular & charge distributions of the fragments are also compared with the statistical model of GEMINI. The results turn out to be that a small proportion of the statistical evaporation component exists in the forward angles while in the intermediate angle region, this component increases to some extent. However, its ratio is still small. It is found that the equilibrium evaporation component decreases gradually when the Z of the fragments becomes smaller. 相似文献