Imaging source with Gaussian proper time distribution

Making use of the maximum entropy method, we study the most probable source function in heavy ion collisions. An anisotropic Gaussian source is deduced by simply assuming that the particles are emitted within a finite proper-time. The general relations between the most probable source function and the minimal assumptions are discussed, which are instructive in constructing a self-consistent source function from observed Hanbury-Brown/Twiss（HBT） correlations.     

Application of the Onsager-Machlup function to nonlinear diffusion processes

The Onsager-Machlup function for a process with nonlinear drift and constant diffusion is considered. The equation of motion for the most probable path is given and its solutions are discussed in the case of the anharmonic oscillator. It is shown that in the case of the laser equation the autocorrelation times are qualitatively reproduced by means of the most probable path.     

Cosmological Wave Function and Wormhole Wave Function with a Conformal Complex Scalar Field

Quantum cosmology and the quantum wormhole witha conformal complex scalar field are discussed, thecorresponding Wheeler-DeWitt equations are obtained, andthe cosmological wave functions and wormhole wave functions are calculated, respectively,with different boundary conditions. From thecosmological wave function it is found that theprobability density of the universe is zero at a = 0,while at the ground state the most probable radius is aboutthe Planck scale. It is also shown that there exist twodifferent types of universes, which can be connected bythe quantum tunneling effect, transiting from one region to another. It follows from thewormhole wave function that the most probable radius ofthe wormholes is about the Planck scale, which impliesthat the wormhole is steady due to the quantumeffect.     

Morphological studies of nanostructures from directed cluster beam deposition

Tin clusters with a most probable size of 2.2 nm are formed from a magnetron plasma aggregation cluster source and deposited on the amorphous carbon and silicon surface. The morphologies of the cluster-based nanostructures formed by directed cluster beam deposition with different cluster energies and incident angles are analyzed based on the transmission electron microscope (TEM) and atomic force microscope (AFM) observation.     

On the causes of negative source impedance in the measurement of intake and exhaust noise sources

In order to evaluate the acoustic field within a duct system some knowledge is required about the acoustic source, which is characterized by frequency-dependent values of both strength and impedance. However, in using various experimental techniques for various types of source to obtain these values, negative real parts of the source impedance have been measured. Negative source resistance is physically implausible. In some instances, one measurement method gives positive values of source resistance where another gives negative values. This paper reviews the possible causes of the problem, with reference to experimental and theoretical results, in an attempt to clarify the issue. Various possible origins of a negative source resistance have been investigated. It is noted that, for the time being, the violation of the assumption of a time-invariant source and the defect in the inherent algorithm of the load method are the most probable origins of the negative source resistance.     

Neutron emission from KSTAR Ohmically heated plasmas

An un-calibrated sensitive ³He detector was used to monitor the KSTAR neutron rate during Ohmically heated discharges. Neutrons were detected for every shot. If the neutrons were from D-D reactions then there should be a dependence on the ion temperature. We obtained ion temperature, electron density, Ohmic heating input power measurements, etc. from standard diagnostics. The study shows no observable dependence on the Ohmic power, ion temperature, or calculated source strength. It appears that the neutrons are from sources other than D-D reactions. The most probable source is high-energy runaway electrons.     

Ground state rotational parameters and fundamental vibration frequencies for isotopically substituted diboranes

The present spectroscopic structural information on diborane derives from infrared studies of B₂H₆ and B₂D₆ species only. Due to the impossibility of selective isotopic substitution in diborane, and the consequent coexistence of a number of isotopic species in any partially deuterated sample, the most probable source of further structural information of quality will be from microwave studies of asymmetrically deuterated species. To assist in the assignment of the overlapping spectra that will occur, accurate rotation and quartic distortion constants are presented for the ground states of all isotopic diboranes in terms of existing zero-point average structural parameters and isotopic changes in these calculated through the harmonic potential function. Sets of fundamental anharmonic vibration frequencies are calculated in order that interference from low-lying vibrations with significant populations at ambient temperatures may be anticipated.     

End-to-end distribution functions for polymers having a most probable molecular weight distribution

End-to-end chain distribution functions for a polymer with a most probable molecular weight distribution are obtained by assuming the end-to-end distribution for each molecular weight species is Gaussian and the degree of polymerization is large. The resulting radial distribution functions using the most probable number and weight species distributions are:

W_n (r,p) = k²re-^kr and W_w (r,p) = k³r²/2 e^?kr

respectively, where k is a function of the short-range effects and the extent of the reaction is p. The first and second moments of these functions are identical with those obtained by taking the number and weight averages of the moments for the monodisperse case. The most probable values of r, which cannot be obtained by the latter method, are found to be 1/k and 2/k, respectively, using the above distributions.     

Evolution of a randomly modulated breather in a nonlinear medium

The evolution of a randomly modulated sine-Gordon breather in a nonlinear medium is studied theoretically. The initial wave field is affected by multiplicative noise. For breather amplitude and velocity, the probability distribution function is determined by means of the inverse scattering transform and the method of cumulants. The distributions are shown to be non-Gaussian. The mean and the most probable values of the breather amplitude and velocity are calculated.     

Generalized thermal radiation from arbitrary fractional dimension

Properties of the thermal radiation from arbitrary fractional dimension are investigated. Generalized blackbody radiation for arbitrary dimension can be obtained and the energy density is shown as a function of arbitrary dimension as well as temperature. Maximum frequency factor representing the relation between most probable photon energy and thermal energy is shown as a function of arbitrary fractional dimension. It is also shown how to measure the arbitrary fractional dimension of the body with thermal radiation.     

Noncommutative quantum cosmology

We propose a model for noncommutative quantum cosmology by means of a deformation of minisuperspace. For the Kantowski-Sachs metric we are able to find the exact wave function. We construct wave packets and show that new quantum states that "compete" to be the most probable state appear, in clear contrast with the commutative case. A tunneling process could be possible among these states.     

BL Lacertae are probable sources of the observed ultrahigh energy cosmic rays

We calculate an angular correlation function between ultrahigh energy cosmic rays (UHECR), observed by Yakutsk and AGASA experiments, and the most powerful BL Lacertae objects. We find significant correlations with the probability of statistical fluctuation less than 10^?4, including penalty for selecting the subset of the brightest BL Lacs. We conclude that some of the BL Lacs are sources of the observed UHECR and present a list of the most probable candidates.     

Origin of the growth induced anisotropy in (YBi)3Fe5O12 films

The single-ion anisotropy model together with the superposition model of the zero field splitting are used to analyse the growth-induced anisotropy of YIG films containing Bi³⁺ ions. Three different mechanisms are discussed. It is shown that the most probable source of anisotropy is the modification of the electron structure of Fe³⁺ ions by interactions in Fe³⁺O²;Bi³⁺ triads.     

Most probable transition paths in eutrophicated lake ecosystem under Gaussian white noise and periodic force

The effects of stochastic perturbations and periodic excitations on the eutrophicated lake ecosystem are explored. Unlike the existing work in detecting early warning signals, this paper presents the most probable transition paths to characterize the regime shifts. The most probable transition paths are obtained by minimizing the Freidlin-Wentzell (FW) action functional and Onsager-Machlup (OM) action functional, respectively. The most probable path shows the movement trend of the lake eutrophication system under noise excitation, and describes the global transition behavior of the system. Under the excitation of Gaussian noise, the results show that the stability of the eutrophic state and the oligotrophic state has different results from two perspectives of potential well and the most probable transition paths. Under the excitation of Gaussian white noise and periodic force, we find that the transition occurs near the nearest distance between the stable periodic solution and the unstable periodic solution.     

Correlation between fractional independent yields and neutron-to-proton ratio of fission products in low energy fission

Fractional independent yields of fission products in the thermal neutron-induced fission of²³³U,²³⁵U,²³⁹Pu,²⁴¹Pu and in the spontaneous fission of²⁵²Cf have been correlated with the neutron-to-proton ratio of the fission products. The yields of the products from a fissioning system, when plotted as a function of neutron-to-proton (N/Z) ratio of fission preducts, fall on two Gaussian distribution corresponding to light and heavy fission products. The centroids of the distribution or the most probable value of neutron-to-proton ratio is found to be very close to theN/Z of the fissioning nucleus. From the most probable value ofN/Z the various parameters of charge distribution e.g. most probable massA _p, most probable chargeZ _p, the mass dispersionσ _Aand the charge dispersionσ _Zhave been obtained and are in good agreement with the experimental values ofA _pandZ _p.     

Observation of the quasar 3C47 with the interferometer URAN at decametric wavelengths

Preliminary results of the observation of the angular structure of the quasar 3C47 at 20 and 25 MHz using the URAN-1 interferometer are presented. The most probable model of the brightness distribution of this source at decameter wavelengths has been determined. This model consists of two extended components having angular dimensions about 22 arcsec and separated by about 50 arcsec.Radioastronomical Institute, Ukrainian Academy of Sciences, Khar'kov. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 38, No. 6, pp. 511–521, June, 1995.     

DLA模型的最可几方法研究

用最可几方法对DLA模型进行了研究，求出了DLA集团粒子的最可几分布、分维数和屏蔽指数，所得结果与计算机模拟结果相符合 关键词：     

Shape of the geometrically active atomic states of carbon

We have developed a computer code for {\em ab initio} the variational configuration interaction calculation of the electronic structure of atoms via variationally optimized Lagurre type orbitals, treating the orbital effective charges as variational parameters. Excited states of the same symmetry, in order to avoid the inherent restrictions of the standard method of Hylleraas--Unheim and MacDonald, are computed variationally by minimizing the recently developed minimization functionals for excited states. By computing, at the minimum, the one-electron density and the probability distribution of the two-electron angle, and the most probable two-electron angle, we investigate the atomic states of the carbon atom. We show that, without resorting to the (admittedly unproven) concept of hybridization, as an intrinsic property of the atomic wave function, the most probable value of the two-electron angle is around the known angles of carbon bonding, i.e. either 109^\circ or 120^\circ or 180^\circ, depending on each low-lying state of the bare carbon atom.     

Transport properties under the influence of finite friction

Using the Langevin Monte Carlo method,the influence of friction on the directed motion of a Brownian particle driven by an external noise source is investigated.The results show that the exitence and change of the environment friction influence the establishment and development of the steady motion of a Brownian particle derived by nonequilibrium fluctuation.The most probable correlation time,which corresponds to the maximum current,is inversely proportional to the friction coefficient.The abnormal transition of the current with different friction appears because of the coupling between the effective ratchet potential and coloured noise intensity.