Vol. 43, No. 5 (1994)
1994-03-05
GENERAL
1994, 43 (5): 689-693.
doi: 10.7498/aps.43.689
Abstract +
The SOq(4) quantum algebra is used for the description of a q-deformed 3-dimensional hydrogen atom. The energy spectrum and degenercy of the q-deformed 3-dimension and 2-dimensional hydrogen atom are obtained respectively.
1994, 43 (5): 694-698.
doi: 10.7498/aps.43.694
Abstract +
The effect of gravitational radiation damping on the variation of the orbital elements of binary system is studied further base on our previous work[1].The result and correction for the previous paper are presented. The effect of gravitational damping on the time of passing perigee of binary star is given. The result shows clearly that the gravitational damping results in both the periodic and secular variation of the time of passing perigee, that is, the time of passing perigee moves up in every revolution. The numerical estimation for the effect on the variation of the time of passing perigee of binary stars, Y Cyg, PSR 1913+16 and PSR 2303+24 been made.
1994, 43 (5): 699-706.
doi: 10.7498/aps.43.699
Abstract +
The differential equation with delayed feedback of the optical bistable system is discretized into a two-dimensional mapping. It is shown that the four-fold oscil-lation mode presents instead of single-mode oscillation upon the loss of stability of the system and that the four modes enter chaos with period-doubling cascade independently with the change of parameter A. In addition, a coexisting attractor is found in the window of period-three. The basin of the coexisting attractor is a fractal structure similar to the two-dimensional Mandeblort set.
1994, 43 (5): 707-716.
doi: 10.7498/aps.43.707
Abstract +
It is demonstrated that the mean field (Landau) theory of critical phenomena (including the two kinds of critical point) and transitions can also be applied to the increasing absorption optical bistubility (IAOB), far from equilibrium. On the basis of analysing the dynamical fea Lures of the IAOB model proposed recently[９］, the socalled quasi-thermodynamic potential is introduced. This potential, near the critical point (of the second kind), reflects not only the general properties of phase transitions in bistable systems, but also the specific characteristics of the IAOB.
THE PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
1994, 43 (5): 717-724.
doi: 10.7498/aps.43.717
Abstract +
In this paper, we assume there exist no three-body forces in a baryon. So that the constraint equations for two particles Pi2+U(x2)+mi2=0 (i=1，2 )can be applied to the SU3 model of the baryon. Next, we take U(x2) as a+bx2. By use of a proper coordinate transformation, the internal motion of the baryon can be reduced to double covariant harmonic oscillators. From the Kustannheimo-Stiefel transformation, the problem of a covariant harmonic oscillator can be transformed to that of a threedimensional hydrogen atom with constranits. On that basis, the difficulty of the excitation of the time degree of freedom can be avoided naturally and the mass-squared formula for baryons can be obtained.
NUCLEAR PHYSICS
1994, 43 (5): 725-733.
doi: 10.7498/aps.43.725
Abstract +
The Hill-Wheeler formula is applied to deriving the equation of state for finite nuclei with the Gogny effective interaction in the framework of the Hartree-Fock theory. The reasonable zero-temperature saturation properties is obtained, and the critical temperature for liquid-gas phase transition of finite nuclei is found to be around 12MeV. It is found that the phenomenological formula for surface energy which is used widely is not available when the density is far away from the normal nuclear density, and a new formula is proposed.
CLASSICAL AREA OF PHENOMENOLOGY
1994, 43 (5): 734-741.
doi: 10.7498/aps.43.734
Abstract +
The nonlinear Schr?dinger equation (NLS) including gain effect is derived from quasi-NLS equation which describes the behavior of soliton pulses in the fiber with slowly decreasing dispersion. The solution of this equation and pulse-width evolution expression are given. For step-index profile single-mode fiber, ordinary relationship between fiber structure parameters and gain coefficient are obtained. Numerical simulation shows that the fiber with slowly decreasing dispersion not only can compensate for soliton broadening caused by fiber loss, but also can compress soliton pulses.
1994, 43 (5): 742-747.
doi: 10.7498/aps.43.742
Abstract +
This paper presents a closed-form analysis method of nonlinear mirror mode locking of a homogeneously broadened Laser. The pulse envelope we obtained is a hyperbolic secant function of time. We obtain the simple analytic expression for the pulse length and discuss the results.
PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
1994, 43 (5): 748-755.
doi: 10.7498/aps.43.748
Abstract +
We present the studies of physical mechanisms of wall and volume emissions of X-ray for different type cavity targets on "Shen-guang" facility. The wavelength 1.053 μm, pulse shape-Gauss type, energy ～500-700J/beam, pulse width ～600-1000ps laser are used to irradiate cylindrical Hohlraum from two ends. The typical target consists of three cylindrical sections of which two ends are absorption-conver-sion regions of laser energy (source region), and the median is imploding region, which is heated by radiation energy from source region. The experiment results of X-ray wall and volume emission and some analyses are presented.
1994, 43 (5): 756-765.
doi: 10.7498/aps.43.756
Abstract +
In this paper, the universal set of degenerate and nearly degenerate four-wave mixing nonlinear coupling equations in plasma is presented in the transmission grating configuration and its exact solution appropriate for arbitrary nonlinear complex coupling parameters is given. This solution is not only suitable for photorafractive materials it can also be helpful for further theoretical study of FWM's phase conju-gation and development of new model nonlinear optical devices.
1994, 43 (5): 766-771.
doi: 10.7498/aps.43.766
Abstract +
Nonlinear behavior of stimulated Raman scattering (SRS) in inhomogeneous plasma is investigated numerically with aperiodic boundary conditions. The effects that modify SRS behavior with stimulated Brillouin scattering (SBS) and Langmuir driven ion fluctuation are 1) nonlinear coupling of Langmuir/ion acoustic wave and 2) energy competition between SRS and SBS. The various processes of the nonlinear coupling which may inhibit SRS are discussed and the SRS evolution features are illustrated in inhomogeneous 1D plasma. Langmuir wave conversion to more strongly damped waves appear to be important to suppress SRS. The γeff,R/γeff,B, the ratio of growth rates of SRS and SBS, and lR/lB, the ratio of growth lengths are presented as two important parameters to define the different paths of simutaneous SRS/SBS evolution. When γeff,Reff,B or lR/lB, SBS is potent to saturate even terminate SRS.
CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
1994, 43 (5): 772-778.
doi: 10.7498/aps.43.772
Abstract +
An expression of relation of X-ray diffraction integrated width and the different coherent domain sizes associated with sublattices is obtained. We conclude that the structural defect has no influence on the X-ray diffraction integrated intensity. A method for studying defect is suggested.
1994, 43 (5): 779-784.
doi: 10.7498/aps.43.779
Abstract +
The deep levels of Ga０．４７Ｉｎ０．５３As/InP lasers with broad, proton-bombarded stripe contacts and SQW (Single Quantum Well) grown by LP一MOVPE have been studied using DLTS (Deep Level Transient Spectroscopy) technique. DLTS Spectra of samples show that hole traps H1(Eｖ+0.09eV) and H2(Eｖ+O.11eV) and electron traps El (Eｖ-0.35eV) and E2 (Eｖ-0.42eV) present in Ga０．４７Ｉｎ０．５３As layer of lasers with broad and proton-bombarded stripe contacts, respectively. These traps may be related to Zn introduction in Ga０．４７Ｉｎ０．５３ As layer, native defect and interactions between H1 and damage induced by proton-bombardment, respectively. They may spatially localize in Ga０．４７Ｉｎ０．５３As layer and interface regions of discontinous variation In mole fraction of Ga1-xInx As layer with XIn=0.53.
1994, 43 (5): 785-789.
doi: 10.7498/aps.43.785
Abstract +
The deep levels of n-Si/n+一Si interface and near the interface in the n-Si have been studies using spread resistance probe (SRP) and deep level transient spectroscopy (DLTS) techniques in silicon direct bonding. The experimental results show that a dominant electron trap, having energy level position of Eｃ－0.39eV and concentration in the range of l013－１０14ｃｍ-3, was observed. This trap is strongly related to vacancies of n-Si/n+-Si interface and near the interface in the n-Si induced by high temperature(1000一11000C) treatment in SDB processing.
1994, 43 (5): 790-798.
doi: 10.7498/aps.43.790
Abstract +
We have used the dielectric-continuum model to study the surface and interface optical-phonon modes in a four-layer heterostructure with finite thickness. The eige-nvectors, the dispersion relation and the interface charge densities are obtained. All the previous results for a dielectric slab, bilayer, trilayer and infinite four-layer he-terostructures can be reded-iced from our general relation for a finite four-layer he-terostructure. The dispersion relations and their numerical illustration for some inte-resting and practical structures such as a finite step-quantum-well are also given. This work can be regarded as a generalization of the formalism in reference [8].
1994, 43 (5): 799-802.
doi: 10.7498/aps.43.799
Abstract +
Thermal expansion properties of Fe-based nanocrystalline Fe１３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９ and Ｆｅ９１Ｚｒ７Ｂ２ alloys are studied, and are compared with that of the amorphous alloys with the same composition. The experimental results indicated that, below Curie temperature, the thermal expansion coefficients of the nanocrystalline alloys are much greater than that of the amorphous alloys, and above Curie temperature, the thermal expansion coefficients of the nanocrystalline alloys exceed that of the amorphous alloys a little. We believe that the difference of the thermal expansion between Fe-based nanocrystalline and amorphous alloys is related to the Invar effect.
CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
1994, 43 (5): 803-808.
doi: 10.7498/aps.43.803
Abstract +
The electronic stucture of three kinds of MoSi2(001)surface with C11b crystal structure were studied by using LMTO一ASA method, their surface total electronic densities of states and local densities of states of surface layer as well as partial densities of states, were provided and compared with the correlated atomic bulk densities of states. As to the stability of the surfaces, the densities of states on Fermi level's were discussed, the Si monolayer surface is the most stable one among them, which support the experimental results obtained by Kemoda et al.
1994, 43 (5): 809-815.
doi: 10.7498/aps.43.809
Abstract +
The characteristics of current density-voltage (J一V) and capacitance-voltage of CuPc/InP rectifying heterojunction energy barrier is measured, and that the effects of density of states at CuPc/InP interface on Raman scattering of CuPc LB film are studied.
1994, 43 (5): 816-822.
doi: 10.7498/aps.43.816
Abstract +
In this paper, we study the states of electron in one-dimensional potential Ｖn＝λｃｏｓ（Ｑn＋ａｎｖ）（０＜ｖ＜１），calculate the eigenvalues and localized exponents. For Ｑ＝２π／３, the energy band is constructed by three subbands. There are two mobility edges in every subband provided that λ<2. We study the nature of the localized and extended eigenstates and mobility edge of this system as a function of λ，ν and α.
1994, 43 (5): 823-828.
doi: 10.7498/aps.43.823
Abstract +
Tungsten silicide films have been sputtered onto silicon substrate and annealed at temperature ranging from 400 to 1000℃ in vacuum. The structure and defect of each film is detected by X-ray diffraction (XRD) and positron annihilation technology (PAT), respectively. The sheet resistance has been measured and the result in-dicates that the sheet resistance of films decrease steeply as a result of annealing in the range of 600-700℃. This phenomenon corresponds to the crystallization of W5Ｓｉ3 tetragonal phase in films which has been certified by XRD. Electrical properties of films are sensitive to structure and defects in films and electrical measurement can be used as a good probe for the study on the characteristics of films.
1994, 43 (5): 829-833.
doi: 10.7498/aps.43.829
Abstract +
We have prepared Na-doped Bi2Sr2CaCu2O8+y(x=0，0.4，0.5, 0.6, 0.7，0.8，1) samples by melting process. The transition temperature of the samples increased up to 90K, and maximum Tc0 achieved was 92.5K. During annealing in flowing oxygen at-mosphere, the Tc of the undoped sample degrade but in the Na-doped sample there is no dramatic Tc change, that indicates their Tc increase have different mechanism. So we believe Na substitution of Bi may destroy the charge balance of BiO layers, the electrons in CuO planes transfer to BiO layers thus create holes in Cu0 planes, the attraction between holes and electrons may be responsible for the superconductivity.
1994, 43 (5): 834-838.
doi: 10.7498/aps.43.834
Abstract +
The microwave joining of Y-123 superconductors was studied. It was discovered that after joining the joined region became denser and some impurities such as Ｙ2ＢａＣｕＯx,Ｂａ2-yＣｕyＯx and CuO were easyly detected. After post-annealing in air at 960℃ for 15h and cooled to room temperature, Ｙ2ＢａＣｕＯx was obviously diminished, Ｂａ2-yＣｕyＯx almost disappeared completely. And Tc of the joined specimen was 89.7, 1.6K lower than that of the original sample. But during the post-treatment, the superconductor in the joined region was recrystallized, the joined region was widened and the holes were enlarged.
1994, 43 (5): 839-845.
doi: 10.7498/aps.43.839
Abstract +
Based on the Peierls-Hubbard Hamiltonian, the influence of electron-phonon inte-raction on the spin excitation of itinerant electron system has been analysed. It is shown that the interaction not only changes the dynamic property of －＋（ｑ，ω），but also causes the gap between two spin subbands to become narrow, which makes the electron-hole pairs easy to be excited singly. It should be emphasized that the spin excitation spectrum has an energy gap duo to the presence of above-mentioned electron-phonon interaction.
1994, 43 (5): 846-850.
doi: 10.7498/aps.43.846
Abstract +
Formation, structure and magnetic properties of Ｓｍ2Ｆｅ17-xＭxＣ1.5（Ｍ＝Ｇａ，Ｓｉ） compounds prepared by arc-melting were studied. The Ｓｍ2Ｆｅ17-xGaxＣ1.5(3≤x≤6) carbides crystallize in the rhombohedral Ｔｈ2Ｚｎ17-type structure and the single-phase compund of Ｓｍ2Ｆｅ17-xSixＣ1.5 can only be obtained as x is 2. It is found that the Curie temperature of Ｓｍ2Ｆｅ17-xGaxＣ1.5 compounds decreases monotonically with increasing Ga concentration x from 633K for x=2 to 351K for x=6，and the Tc of Ｓｍ2Ｆｅ15Si2Ｃ1.5 compound is 578K. All compounds studied in this work exhibit an easy c-axis anisotropy at room temperature. The anisotropy field of Ｓｍ2Ｆｅ14Ga3Ｃ1.5 and Ｓｍ2Ｆｅ15Si2Ｃ1.5 compounds is found td be 90 and 115 kOe, respectively. A room-temperature coercivity of 16 kOe is obtained in rapidly quenched Ｓｍ2Ｆｅ15Si2Ｃ1.5 alloy prepared at。speed of 25 m/s.
1994, 43 (5): 851-857.
doi: 10.7498/aps.43.851
Abstract +
We investigate the photoluminescence properties of Cr3+:ZnWO4 single crystals which channels all the fluorescence into the broadband 4T2(t22e) to 4A2(t32) transition at about 990nm wavelength. Experiment results of the absorption spectra and the excitation spectrum, temperature dependence of the emission spectra, decay curves of Cr3+ ions are presented and discussed. The most efficient excitation wavelength is in the red region. Radiative decay from the luminescence level to the ground level is characterized by broad emission bands as a consequence of a strong electron-phonon interaction ——Hua-Rhys factor S(300K)=4.22, S(12.7K) = 7.09, the average pho-non energy hv(300K)=405cm-1, hv(12.7K)=213cm-1. The zero-phonon transition line probably is at wavelength of 856.7nm. If there are two kinds of Cr3+ center, one is compensated by the adjacent vacancy(1.8μs), and the other is compersated nonl-ocally (5.45μs).
GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS
1994, 43 (5): 858-864.
doi: 10.7498/aps.43.858
Abstract +
Hawking radiation of charged Dirac particles near the event horizons of the general spherically symmetric and non-static black holes is studied. We obtain the equation determining the location of event horizon, the radiation temperature function and the Hawking thermal spectrum formula.
