摘要：
In this paper, unified colored noise approximation is extended to treat the systems driven by Poisson colored noise cursive Greek chi = υ(cursive Greek chi) + gξcp(t). We arrive the evolution equation of the probability distribution Pi(cursive Greek chi, τ) and the stationary probability distribution ps(cursive Greek chi, τ). These equations are valid only if r(cursive Greek chi, τ) ≡ τ-1/2[1 - τG(cursive Greek chi)/g(cursive Greek chi)] (G(cursive Greek chi) ≡ υ′(cursive Greek chi)g(cursive Greek chi) - υ(g)g′(cursive Greek chi)) is large enough (positive) and t ≫ τ/τ(cursive Greek chi, τ), but r is not restricted. As an application, we derive the nonlinear relaxation time (NLRT) for the processes driven by Poisson colored noise and evaluate the NLRT for the approximative Ginzburg-Landon model under small τ.
摘要：
The dimensional regularization is applied to three-loop vacuum graphs in massless QED to evaluate temperature-dependent ultraviolet divergences and infrared divergences in arbitrary covariant gauge. They both are shown to be absent due to cancellations among themselves, and the cancellations are gauge-independent although the individual divergences are gauge-dependent.
关键词：
finite-size effects;phi(4) theory;upper critical dimension;five-dimensional Ising model
摘要：
We present a perturbative calculation of finite-size effects near $T_c$ of the $\phi^4$ lattice model in a $d$-dimensional cubic geometry of size $L$ with periodic boundary conditions for $d > 4$. The structural differences between the $\phi^4$ lattice theory and the $\phi^4$ field theory found previously in the spherical limit are shown to exist also for a finite number of components of the order parameter. The two-variable finite-size scaling functions of the field theory are nonuniversal whereas those of the lattice theory are independent of the nonuniversal model parameters.One-loop results for finite-size scaling functions are derived. Their structure disagrees with the single-variable scaling form of the lowest-mode approximation for any finite $\xi/L$ where $\xi$ is the bulk correlation length. At $T_c$, the large-$L$ behavior becomes lowest-mode like for the lattice model but not for the field-theoretic model. Characteristic temperatures close to $T_c$ of the lattice model, such as $T_{max}(L)$ of the maximum of the susceptibility $\chi$, are found to scale asymptotically as $T_c - T_{max}(L) \sim L^{-d/2}$, in agreement with previous Monte Carlo (MC) data for the five-dimensional Ising model. We also predict $\chi_{max} \sim L^{d/2}$ asymptotically. On a quantitative level, the asymptotic amplitudes of this large -$L$ behavior close to $T_c$ have not been observed in previous MC simulations at $d = 5$ because of nonnegligible finite-size terms $\sim L^{(4-d)/2}$ caused by the inhomogeneous modes. These terms identify the possible origin of a significant discrepancy between the lowest-mode approximation and previous MC data. MC data of larger systems would be desirable for testing the magnitude of the $L^{(4-d)/2}$ and $L^{4-d}$ terms predicted by our theory.
作者机构：
[Adamovich, MI] Inst High Energy Phys, Alma Ata, Kazakhstan.;Acad Sinica, Inst High Energy Phys, Beijing, Peoples R China.;Inst Gravitat & Space Res, Bucharest, Romania.;Panjab Univ, Dept Phys, Chandigarh 160014, India.;Hunan Educ Inst, Dept Phys, Changsha, Hunan, Peoples R China.
通讯机构：
[Adamovich, MI] I;Inst High Energy Phys, Alma Ata, Kazakhstan.
摘要：
We analyse the multifractal structure of moments G(q) in terms of a new variable X on data of (197)AU, S-32, and O-16 induced interactions with emulsion nuclei and Monte Carlo generated samples. The dynamical properties of the produced particles are mapped onto multifractal spectra. We compare In(G) in experimental data of Au-197, S-32, and O-16 with pure statistical fluctuations. It is shown that the stochasticity plays an important role for the G-moments.
作者机构：
[Ding, Zirong; Peng, Chen; Zhang, Lun] College of Chemistry, Wuhan University, Wuhan, China;[Zhao, Qingbo; Chen, Sunian] Center of Instrumental Analysis, Wuhan University, Wuhan, China;[Qi, Shoure] Department of Physics, Huazhong Normal University, Wuhan, China
摘要：
The title organometallic compounds were synthesized by the condensation of formyl and acetyl ferrocene with cyanoacetyl, propionyl, butyryl, o-furoyl, o-thiofuroyl and m-pyridinecarboxy hydrazine in anhydrous ethanol under reflux. The IR, <sup>1</sup>H NMR, MS, and Mossbauer spectra for these compounds were recorded and are discussed.
关键词：
finite-size scaling;phi(4) field theory;upper critical dimension;five-dimensional Ising model
摘要：
We demonstrate that the standard O(n) symmetric phi(4) field theory does not correctly describe the leading finite-size effects near the critical point of spin systems with periodic boundary conditions on a d-dimensional lattice with d > 4. We show that these finite-size effects require a description in terms of a lattice Hamiltonian. For n --> infinity and n = 1, explicit results are given for the susceptibility and for the Binder cumulant. They imply that these quantities do not have the universal properties predicted previously and that recent analyses of Monte Carlo results for the five-dimensional Ising model are not conclusive.
期刊：
Chinese Astronomy and Astrophysics,1998年22(4):386-394 ISSN：0275-1062
通讯作者：
Yang, PB
作者机构：
[Yang, PB] Cent China Normal Univ, Inst Astrophys, Wuhan 430079, Peoples R China.;Wuhan Coll Text Sci & Technol, Wuhan 430073, Peoples R China.
通讯机构：
[Yang, PB] C;Cent China Normal Univ, Inst Astrophys, Wuhan 430079, Peoples R China.
关键词：
hot accretion flow;advection;e(+/-) pair process
摘要：
By means of the self-similar relations of the hot flow with advection and nonthermal e± pair production, we examine the radial structure of such a flow. Some typical features have been confirmed, and several new results obtained: there exists a critical radius rcr; the local cooling rate is inversely proportional to the square of the mass of the central object; the pair density in the accretion flow with advection is higher than in the SLE disk.
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, Hungary.;Hubei Univ, Dept Phys, Wuhan 430062, Peoples R China.
通讯机构：
[Yang, CB] H;Hua Zhong Normal Univ, Inst Particle Phys, Wuhan 430079, Peoples R China.
摘要：
Deviation of the multiplicity distribution Pq in a small bin from its Poisson counterpart pq is studied within the Ginzburg-Landau description for a second-order quark-hadron phase transition. The dynamical factor dq≡Pq/pq for the distribution and the ratio Dq≡dq/d1 are defined, and novel scaling behaviors between Dq are found which can be used to detect the formation of quark-gluon plasma. The study of dq and Dq is also very interesting for other multiparticle production processes without a phase transition.
作者机构：
Department of Physics, Huazhong Normal University, Wuhan 430079, China;[Jin-Sheng P.; Peng Z.] Department of Applied Mathematics and Theoretical Physics, Queen's University of Belfast, Belfast BT 7 INN, United Kingdom;[Gao-Xiang L.] Department of Physics, Huazhong Normal University, Wuhan 430079, China, Department of Applied Mathematics and Theoretical Physics, Queen's University of Belfast, Belfast BT 7 INN, United Kingdom
通讯机构：
[Li, G.-X.] D;Department of Physics, , Wuhan 430079, China
摘要：
We have studied the steady-state behavior of a cascade three-level atom in a two-mode bad cavity which is parametrically driven by a classical field. In the weak field limit, it has been found that the atomic population trapping in the upper-level depends on the cavity photon number not only linearly but also quadratically, and the atomic dipole squeezing can occur.
作者机构：
[Yan, Wenbiao; Wang, Xiaorong; Cai, Xu; Liu, Lianshou; Yang, Chunbin; Qian, Wanyan; Zhou, Daicui] Huazhong Normal Univ, Wuhan, China
通讯机构：
Institute of Particle Physics, Hua-Zhong Normal University, China
关键词：
Ultrarelativistic heavy ion collision;Two particle correlation;Fluctuation
摘要：
Using an aspect of rapidity bins with finite sizes the short-range and long- range behaviors of two-particle correlation, the connection of two particle correlation function with factorial moment and factorial correlator are investigated; and experimental data for 16O+Em interactions at 14.6, 60 and 200 A GeV and 32S+197 Au interactions at 200.A GeV are analyzed. It is shown that the bin-average of two-particle correlation function can naturally give a coordinate description of dynamical fluctuation such as the second order factorial moment (F2) and 1+1 order factorial correlator (F1, 1).
