In this paper a method of direct derivation for the universal R matrix of quantum group Uq(SU(1,1)) is given. It is simple and efficient for quantum groups of low rank at least. By the application of the R matrix obtained, the explicit expression for Casimir invariant of the above guantum group is given. As an application, the second order Casimir operator is rederived as well.
By imposing conformally broken constraints on SL(2,R) WZNW model, we obtain a new classical completely integrable system which contains the famous sinh-Gordon system as a special case. The integrability of this extended sink-Gordon system is exhibited by the existence of the Lax pair with spectral parameters. And its funda-mental .Poisson-Lie brackets can be ultralocalized, corresponding classical...
On the basis of the study in Ref [4],we construct the dressing transformations of the fundamental variables and show the dressing symmetry of the constrained system (extended sinh -Gordon equations). Finally, we discuss the ultralocalizable-criterion of an arbitrary 2D integrable model.
The one-dimensional biquadratic map is studied by means of symbolic dynamics in two parameter plane. The skeleton of superstable orbits and the joints in the kne-ading plane have been constructed. A criterion of the existence of topological chaos has been given according to the topological entropy.
Since the equilibrium composition of strange matter is crucial to the accurate calculation of its neutrino energy loss rates, we determine the composition by using the thermodynamic potentials (per unit volume) of the strange matter, and find that the electron abundance decreases with the strong interaction coupling constant or ba-ryon density. After deriving the formula of neutrino energy loss r...
By using the theory of configuration-interaction, we ireade a analysis of the effect of configuration interaction on the autoionization rates and branch ratios of the configurations 2p53s3l(l=0,1,2) for the Nalike Cu ion. It is shown that the autoionization rates in all the three configurations are changed substantially when the configuration-interaction are included in comparing with the calculat...
The theoretical analysis of two-photon photoacoustic effect is presented. The wave equation of two-photon photoacoustic efffct is derived. And the general expre-ssion of two-photon photoacoustic effect is given.
The solution for the equations of atomic density matrix is obtained, without resorting to any approximation, in the Ξ-type of three-level system with lower-level coherence. The conditions on pumping are analyzed in the strong-coherence case for lasing without inversion and the saturation term is derived.
Nonlinear simulation of the entropy-like quantity is given to the equilibrium electrons in a free-electron laser with reversed guide field. Results indicate that the quality of the electron beam may be better than the oae in the case of positive guide field. However, the quality of the beam is spoiled at the antiresonance. The concl-usions from the entropy-like quantity principally coincide with t...
Dynamic processes of the modelocked laser based on a auxiliary coupled cavity containing a nonlinear frequency-doubling crystal has been systematically studied in this paper. And, the specific formulas of the output pulse width of this modelocked laser in instantaneously dynamic equilibrium are given. Moreover, the results of nu-merical analysis and calculation show that its modelocking output pro...
PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
Coupling between atmospheric gravity waves and plasma interchange instability in the equatorial ionosphere is studied. The interchange instability is saturated at a small amplitude by nonlinear effects if there are not any external geophysical distu-rbances to influence it. It is shown that the gravity waves can initiate the interchange instability under some conditions. The initiated instability ...
CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
The C60 single crystals up to mm-size were grown. X-ray diffraction result shows that C60 single crystal is of fcc structure, with lattice parameter of 1.413 nm. An abrupt change of conductivity (at 251K) related to the phase transition shows that C60 single crystal is of high purity and homogeneity. A drop of activation energy around 274K was observed. This activation energy drop may be an indica...
We study a tight binding model Hamiltonian of the one-dimensional Bravais lat-tice. This Hamiltonian contains one impurity energy site and two hopping constants between this site and its two nearest neighbours. The formation and properties of the localized states of this model is analysed by virtue of the Green function method.
Hanis theory of precipitate growth controlled by diffusion is demonstrated by studying the growth of the oxygen precipitates at high temperature with two-step heat treatment. And the nucleation of the oxygen precipitates is disussed according to Ham's theory tantatively.
CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
By using a modified self-consistent variation method, we have calculated the subband structures of n-type inversion layer in p-type HgCdTe NIS (metal-insulator-semiconductor) devices, obtained the ground subband energy E0 and its dependence on both the doping concentration in bulk HgCdTe and the surface electron concent-ration in the inversion layer. In the treament, the influence of non-parabolic...
By using STS, combined with STM imaging, the STS spectra d(lnI)/d(lnV) -eV were measured point by point along a line on the surface of a single crystal graphite. The local density of states (LDOS) around the Fermi level EF obtained from the spectra showed basically an agreement with that of theoretical calculation. By plotting the energy positions of the LDOS peaks around EF with respect to the me...
A new type of AlxGa1-xAs/GaAs beterojunction based on Si δ-doping has been fabricated by MBE method. We measured the magnetoresistances, mobility and Hall resistance of the 2-D electron gas at the junction in a transvers magnetic field from 0.3 to 30K. Using Fourier-transform analysis, the distribution of electrons and their effective masses for each subband are determined. whichare m0*/m0=0.073,m...
A single frequency admittance spectroscopy technique is introduced for determining the band discontinuity on Si/GexSi1-x/Si single quantum well (SQW). By using this method, the more accurate experimental results can be obtaind from a single frequency admittance spectrum. For an alloy with composition x=0.33,we get the activation energy Ea=0.20eV. In order to obtain the value of the band offset,it ...
The temperature coefficient of resistivity (TCR) of Pd thin film with different thicknesses and annealled at different tempertures has been investigated. The experi-mental results indicated that the TCR value of thin films is much smaller than that of bulk material and it also depcnds on grain size of the thin films. It was found that the TCR is higher for larger grain size. The result is explaine...
The phonon vibration characteristics of the Bi2Sr2-xBaxCuOy (x=0, 0.2,0.4) single crystal samples was studied by using Raman scattering measurement. The exp-erimental results show that in the Raman spectra of the Bi2Sr2-xBaxCuOy system the typical phonon vibrational modes mainly appear in the frequency range of 196, 282-310, 460, 625 and 660cm-1, and the intensities of the 196, 282-310, 625, and 6...
Ba-doping effects on the superconducting properties in the Bi2Sr2-xBaxCaCu2Oy single crystals (0≤x≤0.15) and polycrystalline samples (0≤x≤0.3) have been studied. The results show that Ba2+ enters the superconducting phase with a solubi-lity limit. For 2212 phase single crystals, the length of c-axis and the supercondu-cting transition temperature Tc both increase with increasing Ba content. For sl...
In this article, it is revealed that the Ba substitution intensifies the incommens-urate modulation of the Bi-2201 phase, namely the wavelengths of the modulation along b and c directions show obvious decrease. The study of superconductivity of the Ba-doped 2201 shows that the appropriate substitution of Ba for Sr (x≤0.2) can raise the Tc of 2201 phase, but as x exceeds 0.3, Tc decreases sharply, ...
The magnetocaloric effect of several ferrite specimens, with magnetoplumbite structure, spinel structure, garnet structure and perovskite structure respectirely, have been studied experimentally. The effect of substitution of non-magnetic ions on Cu-rie temperature and magnetic entropy are also reported.
Several samples of Cu1-xSnx series were obtained by mechanical alloying, including η-Cu6Sn5 alloy which are difficult to prepare by melting method. XRD results show that the solid solution with nanometer size is formed which including definite alloy phase in each ball milling sample. M?ssbauer spectra indicate that the Sn-rich-phase and the Cu-rich phase exist besides the alloy phase. We suggest t...
The infrared divergence response theory is applied to reorientational relaxation process of Al3+-hole in α-quartz containing Al impurity to study the behaviour of low temperature dielectric relaxation loss properties in this system. Our calculation results showed that the single phononassisted tunneling process makes the main contribution to the dielectric loss for T10 K, the thermally activated r...
In this paper, a technique of proton elastic backscattering (EBS) in the energy range of 1.5-2.5MeV is proposed for the measurement of the total contents of oxy-gen in the films. The accuracy is better than 5% for the film thickness between less than hundreds nm to a few microns.