作者机构：
[Zhou, DC; Wu, T] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Wu, T] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
Multiplicity distributions of negative binomial distribution (NBD) and modified NBD are obtained from it birth process model with an immigration. The ratio of factorial cumulant moment to factorial moment, i.e., H moment is calculated from different multiplicity distributions of NBD, modified NBD and the three fireball model, which shows an oscillatory behavior when there is a truncation of multiplicity. The oscillation of H moment is related to the common character of the truncated multiplicity distributions.
期刊：
Monthly Notices of the Royal Astronomical Society,2000年314(3):453-458 ISSN：0035-8711
通讯作者：
Lu, Y
作者机构：
[Lu, Y] Chinese Acad Sci, Beijing Astron Observ, Beijing 100012, Peoples R China.;Univ Hong Kong, Dept Phys, Hong Kong, Hong Kong, Peoples R China.;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We investigate the runaway instability of configurations consisting of a massive dense but non-self-gravitating thick disc/torus surrounding a massive black hole (MBH). We limit our model parameters to values that result in a self-consistent thick disc around an MBH. We identify, analytically, the index of the angular momentum distribution that will form a thick disc as an initial equilibrium state, and obtain the mass ratio of the disc to the central black hole for which the disc is dominated by the radiation pressure. In our theoretical framework we find that a self-consistent thick disc with constant angular momentum leads to a runaway instability on a dynamical time-scale. However, even a slight increase of the specific angular momentum outwards has a strong stabilizing effect on the accretion process. Finally, we discuss our results and present possible applications to high-energy emission.
期刊：
Astrophysics and Space Science,2000年272(4):383-394 ISSN：0004-640X
通讯作者：
Ding, SX
作者机构：
[Ding, SX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Huazhong Normal Univ, Inst Astrophys, Wuhan 430079, Peoples R China.;Xiang Yang Teachers Coll, Dept Phys, Xiang Fan 441053, Peoples R China.;Chinese Acad Sci, Beijing Astron Observ, Beijing 100080, Peoples R China.
通讯机构：
[Ding, SX] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
The radial-azimuthal instability of gas-pressure-dominated accretion disk with advection is examined in this paper. We find that the including of very little advection has significant effects on two acoustic modes, which are no longer complex conjugates of each other. They increase the instability of the O-mode and damp that of the I-mode. We also find that when the azimuthal perturbations are considered, the stability properties of disk are different from that in pure radial perturbation case. The increase of azimuthal wavenumber will stabilize the acoustic modes but make the viscous mode more unstable and does not change the thermal mode very much for optically thin disk. The I-mode is more stable. The O-mode, viscous mode and thermal mode tend to become more unstable with the increase of azimuthal perturbation wavenumber for optically thick disk. For a geometrically slim, advection-dominated disk, the increasing of azimuthal perturbations make thermal mode more unstable and acoustic mode more stable.
作者机构：
[Liu, ZX; Liu, LS; Fu, JH] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Liu, ZX] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
关键词：
erraticity
摘要：
The influence of multiplicity distribution (fluctuation of multiplicity in the event space) on the erraticity behaviour in high energy collisions is investigated via Monte Carlo simulation and compared with the experimental results from NA27 data. It is shown that, the erraticity phenomenon is insensitive to the multiplicity fluctuation. When the average multiplicity is low this phenomenon is dominated by the statistical fluctuations, also in the case of multiplicities fluctuating from event to event.
作者机构：
[Zhang, BW; Li, JR; Hou, DF] Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Zhang, BW] H;Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
关键词：
meson mass;vacuum effects;ρNN interaction;scaling law
摘要：
We studied the medium effects on rho meson mass by taking account of the vacuum effects with the effective Lagrangian approach. We show that the rho meson mass decreases with both temperature and chemical potential. Then we checked the validity of Brown-Rho scaling law in different conditions.
通讯机构：
[Chen, XS] H;Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
关键词：
05.70.Jk Critical point phenomena;64.60.-i General studies of phase transitions
摘要：
Using φ field theory and Monte Carlo (MC) simulation we investigate the finite-size effects of the magnetization M for the three-dimensional Ising model in a finite cubic geometry with periodic boundary conditions. The field theory with infinite cutoff gives a scaling form of the equation of state h/Mδ = f(hLβδ/v,t/h1/βδ) where t = (T - TC)/Tc is the reduced temperature, h is the external field and L is the size of system. Below Tc and at Tc the theory predicts a nonmonotonic dependence of f(x,y) with respect to x ≡ hLβδ/v at fixed y ≡ t/h1/βδ and a crossover from nonmonotonic to monotonic behaviour when y is further increased. These results are confirmed by MC simulation. The scaling function f(x,y) obtained from the field theory is in good quantitative agreement with the finite-size MC data. Good agreement is also found for the bulk value f(∞,0) at Tc.
摘要：
A FitzHugh Nagumo(FHN) neural model,which is double singular stochastic system, is studied.The effects of parameter β,which marks the singular degree of stochastic force at singular point, on the phase transition of the FHN model are discussed when β is non integer.It is shown that the parameter β plays an important role in phase transition of the system, and there is a locking phenomenon in the FHN model.
期刊：
Wuhan University Journal of Natural Sciences,2000年5(3):307-311 ISSN：1007-1202
通讯作者：
Shen, Guo-jin
作者机构：
Department of Physics, Wuhan University of Automobile Industry, Wuhan, 430079, China;Department of Physics, Xiaogan Teachers' College, Xiaogan, Hubei, 432100, China;Department of Physics, Central China Normal University, Wuhan, 430079, China;The State Key Lab of Laser Technology, Huazhong University of Science and Technology, Wuhan, 430074, China;[Shen, Guo-jin] Department of Physics, Wuhan University of Automobile Industry, Wuhan, China
摘要：
The energies and the magnetization of an electron in a piece of metal in the structure of Metal/Insulator/Metal/Insulator… (M/I/M/I…), in a magnetic field, at high temperature, and in range of quantum size thickness of the piece of metal layer have been obtained. The results show that when the thickness of the metal layer becomes smaller, the orbital magnetism of the charged particles which collide with the wall of the metal layer is to vary from diamagnetism to paramagnetism. The smaller the thickness of the metal layer becomes, the more particles will collide with the boundary of the metal layer, and then the paramagnetism becomes stronger. Finally, when the thickness of the metal layer becomes very small (<100 nm), all of the orbital diamagnetism will reverse to paramagnetism, and then the paramagnetization will be almost a maximum constant.
作者机构：
[Li J.-R.; Wang X.] Institute of Particle Physics, Huazhong Normal University, Wuhan 430079, China
通讯机构：
[Wang, X.] I;Institute of Particle Physics, , Wuhan 430079, China
摘要：
By considering the Dcbyc screening and the finite width of soft gluons, the effective two-loop thermodynamic potential in quark-gluon plasma was evaluated via real-time temperature quantum chromodynamics. The result that depends on damping rate of soft transverse gluons as a physical parameter is obtained, and extension of the case including the longitudinal gluon and fermion will be straightforward.
作者机构：
[Hu, XM] Chinese Acad Sci, Shanghai Inst Opt & Fine Mech, Lab High Intens Opt, Shanghai 201800, Peoples R China.;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, XM] C;Chinese Acad Sci, Shanghai Inst Opt & Fine Mech, Lab High Intens Opt, Shanghai 201800, Peoples R China.
摘要：
We present a theory of light amplification in a cavity based on irreversibility of coherent excitation. It is predicted that the irreversibility of coherent excitation leads to a new way of lasing which is different from lasing with and without inversion in the conventional sense. Lasing with dynamically induced inversion is possible in coherently driven systems in which there is no conventional source of irreversible population pumping. This laser displays two interesting and important features: the maximum gain with inversion is substantially greater than gain without inversion, and in spite of the presence of the inversion, the noise intensity is reduced below the shot-noise limit.
作者机构：
[Liu, LS; Fu, JH] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Fu, JH] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
A new signal is proposed for the colour reconnection in the hadronic decay of W+ W- in c(+)c(-) collisions. Using Pythia Monte Carlo it is shown that factorial correlators for W+ and W- without colour reconnection are almost identical to unity, while those for the cases with colour reconnection fall down approximately linearly in the log-log plot. This signal, being based on the factorial correlator, is more sensitive than the ones using only averaged quantities.
