作者机构：
[Yang, CB] Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.;KFKI, RMKI, Div Theory, H-1525 Budapest 114, Hungary.
通讯机构：
[Yang, CB] H;Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
It is suggested that the study of multiplicity difference correlators between two well-separated bins in high-energy heavy-ion collisions can be used as a means to detect evidence of a quark-hadron phase transition. Analytical expressions for the scaled factorial moments of multiplicity difference distribution are obtained for small bin size with mean multiplicity s¯<~0.3 within Ginzburg-Landau description. It is shown that the scaling behaviors between the moments are still valid, though the behaviors of the moments with respect to the bin size are completely different from the so-called intermittency patterns. A universal exponent γ is given to describe the dynamical fluctuations in the phase transition.
作者机构：
[Li, ZY] Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.;Huazhong Univ Sci & Technol, Dept Solid State Elect, Wuhan 430074, Peoples R China.
通讯机构：
[Li, ZY] C;Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
会议名称：
44th International Field Emission Symposium
会议时间：
JUL 07-11, 1997
会议地点：
NATL RES INST MET, TSUKUBA, JAPAN
会议主办单位：
Cent China Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.^Huazhong Univ Sci & Technol, Dept Solid State Elect, Wuhan 430074, Peoples R China.
摘要：
The paper introduced an effective binding energy Lambda'(eff) and emphasized the role it plays in the field evaporation in the configuration of a scanning tunneling microscope (STM). With this Lambda'(eff) an important modification has been made to Tsong's CE model formula for STM [Tien T. Tsong, Phys. Rev. B 44 (1991) 13 703]. As a consequence, for tip-sample distance 5 < d < 13 Angstrom, the high evaporation fields from Tsong's original formula were found greatly reduced. When d = 7.23 Angstrom, the recalculated evaporation field for Au-1 is 0.6 V/Angstrom, which is in good agreement with Chang's experiment [Phys. Rev. Lett. 72 (1994) 574]. Further the evaporation field was found highly localized. For d = 7.52 Angstrom, the evaporation field of Au-1 on top of a Au(1 1 1) surface atom was found several times lower than that at a hollow site. In the calculation we have proposed a universal binding function. In addition selected experimental results on nanostructure formation by positive or negative voltage pulses with Au, Ni, Cu, Pt(Ir) and W tips on Au(1 1 1) substrate with a STM working in atmosphere were presented. The processes were found to bear important feature of field evaporation. (C) 1998 Published by Elsevier Science B.V. All rights reserved.
作者机构：
[Huang, GM; Peng, JS; Li, GX] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Li, GX] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We have investigated the atomic coherent population trapping in a multilevel laser-induced continuum structure system including cascade two-photon processes, in which two sets of quasicontinua of excited levels to be modeled as the Bixon-Jortner quasicontinuum are laser-embedded into a previously structureless atomic continuum. The condition leading to the atomic coherent population trapping and the coherent population trapping state are given explicitly. And the effects of the Fano factors, the laser intensities and the detunings on the amount of population trapped in the atomic bound states and the populations distributed in the two sets of quasicontinua are also examined.
作者机构：
[Hu, Xiang-Ming; Peng, Jin-Sheng] Department of Physics, Central China Normal University, Wuhan 430079, China;Institute of Applied Physics, Central China Normal University, Wuhan 430079, China
通讯机构：
Department of Physics, Central China Normal University, China
摘要：
Photon noise squeezing and its physical mechanism of a driven V-type three-level laser are investigated via Scully-Lamb theory. It is shown that intracavity squeezing of 10% and extracavity squeezing of 20% can be achieved. Even if the amount of squeezing in V system is smaller than that in A system (intracavity squeezing and extracavity squeezing of up to 50 %), both systems have the same mechanism responsible for the squeezing of photon noise.
作者机构：
[Hu, XM; Peng, JS] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, XM] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We investigate the effect of some incoherent steps on the intensity fluctuations in the four-level Lambda quantum-beat laser. It is demonstrated that such a four-level system can produce a squeezed two-mode laser. For the light coming out of this device we may achieve up to 50% intensity noise reduction. A simple physical explanation of the squeezing mechanism for two-mode squeezing is given. (C) 1998 Elsevier Science B.V. All rights reserved.
摘要：
The derivative expansion method has been used to solve the semiclassical kinetic equations of quark-gluon plasma. The nonlinear spatial damping rate, the imaginary part of the wave vector, for the longitudinal secondary color waves in the long wavelength limit has been calculated numerically. (C) 1998 Elsevier Science B.V. All rights reserved.
摘要：
Using emulsion detectors a transverse-momentum analysis of projectile fragments has been performed in Au induced nuclear interactions at 11.6 A GeV/c. Evidence for collective flow of the projectile fragments has been obtained. Angular distributions of the principal vectors of projectile and target fragments have shown strong azimuthal correlation.
作者机构：
[Yang, LT] Huazhong Normal Univ, Inst Astrophys, Wuhan 430070, Peoples R China.;Chinese Acad Sci, Inst Theoret Phys, Beijing 100080, Peoples R China.
通讯机构：
[Yang, LT] H;Huazhong Normal Univ, Inst Astrophys, Wuhan 430070, Peoples R China.
关键词：
Accretion disk;Radial-azimuthal instability
摘要：
The radial-azimuthal instability of an isothermal magnetized accretion disk is examined in this paper. We find that the azimuthal perturbation enhances the instability of the magneto-acoustic and non-axisymmetric modes. The magnetic field induces and enhances the instability of magneto-acoustic modes, but stabilizes the non-axisymmetric modes in the outer disk. The viscous modes are always stable. The instability of magneto-acoustic modes are dominant in this disk.
期刊：
INTERNATIONAL JOURNAL OF MODERN PHYSICS A,1998年13(12):1969-1979 ISSN：0217-751X
通讯作者：
Feng, L
作者机构：
[Feng, L] Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Feng, L] H;Huazhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
According to the cone definition of the jet we propose a practical and effective algorithm to identify jets. Through comparison between the Monte Carlo samples with and without jet(s), the following observations are made. Contrary to what is expected, most of the jetty events do not have high multiplicity. The distributions of multiplicity and (p) over bar t have long tails for the whole event sample because of (mini)jet production, but no such tail for a no-jet event subsample. The average transverse momentum per event (p) over bar t and multiplicity n are positively correlated for the whole event sample, and negatively correlated for the jetty event subsample. Two ratios are introduced to describe the "degree of hardness" of each event and are found to be correlated positively with (p) over bar t, but negatively with multiplicity, indicating that (p) over bar t is a better characteristic parameter to describe the event hardness than multiplicity.
