Vol. 41, No. 12 (1992)
1992, 41 (12): 1913-1918. doi: 10.7498/aps.41.1913
The Gaussian curverture, equatorial and polar circumferences are calculated for the event horizons of two Schwarzschild black holes. Their variations following the change of the distance of two black holes are also examined. The results show that the geometrical property of the horizon of one black hole is affected by the other.
INTERACTION BETWEEN NARROW WAVE BEAM-TYPE HIGH FREQUENCY GRAVITATIONAL RADIATION AND ELECTROMAGNETIC FIELDS
1992, 41 (12): 1919-1928. doi: 10.7498/aps.41.1919
Starting with the Einstein-Maxwell equations of weak gravitational field, we discussed the interaction between narrow wave beam-type high frequency gravitational radiation of crystal space array and electromagnetic fields. The perturbed solutions have been obtained. By our calculation, it is shown that this gravitational wave beam with optimal radiation direction is purely + type polarized in TT coordinate system, and it can make electromagnetic wave, which has the same frequency, to generate perturbed effects of frequency doubling, make static electromagnetic fields to generate cumulative effect linear in time. For the gravitational radiation wave beam with an arbitrary direction, it is also purely+type polarized in the plane perpendicular to the gravitational wave vector. Under the condition of high frequency radiation and laboratory's typical size, difference between TT coordinate and Fermi coordinate systems can be neglected.
1992, 41 (12): 1929-1937. doi: 10.7498/aps.41.1929
The analytical formula for deuteron-nucleus microscopic optical potentials is derived using the mass operator method of Green function, and the nucleon density distributions of target nuclei are determined with the semiclassical variation (SCV) approach. These formula and density distributions are utilized ro evaluate the real and imaginary parts of 2D+40Ca,2D+60Zr and 2D+208Pb optical potentials at different energies. The potentials obtained in this way are fully selfconsistent and microscopic, since the same Skyrme interaction is employed in determining the nucleon density distributions of target nuclei and in clacula-ting the potentials.
1992, 41 (12): 1938-1942. doi: 10.7498/aps.41.1938
In this paper, we report the systematic results of folded LA phonon modes in the a-Si: H/a-SiN:H and a-Si: H/a-SiC:H periodic superlattices. We use the elastic continuum model to obtain the theoretical results, which are in good agreement with the experimental values. Finally, the problem of the existence of frequency-gap at the center of the Brillouin zone is briefly discussed.
ATOMIC AND MOLECULAR PHYSICS
Pulsed OODR technique is applied to investigate ion-pair states in "E" region of iodine. The total excitation energy ranges between 43180 and 43600cm-1 Two ion-pair states, E1(13≤V′(E1)≤17) and E2(15≤V′(E2)≤19) unknown previously are found. T(e1)=41909.13±1.786cm-1,T(e2)=41843±0.033cm-1 (relative to VX= 0, J″x = 0,X1∑oe+). Analysis of the results leads to the conclusion that their energy curves (I+ 3P2+I- 1S0) are lower in "E" region as compared with others (e.g.fOg+) and both are of g symmetry.
CLASSICAL AREA OF PHENOMENOLOGY
1992, 41 (12): 1950-1954. doi: 10.7498/aps.41.1950
The Raman interaction of a pair of two-level atoms with the radiation field is studied. The emission spectra for two interacting processes are calculated in which either two atoms couple to the field with different constants or with the same constant but at the same time the dipole-dipole interaction between two atoms being included in the consideration. The effect of the relative value of two atom-field coupling constants and also that of atomic dipole-dipo-le interaction on the emission spectra are analyzed.
1992, 41 (12): 1955-1960. doi: 10.7498/aps.41.1955
The ratio of the power spectra of random array to whose unit is called the coherent factor. By analyzing the statistical data experiment of ours, we have studied the fine structures of the curves of coherent factor, introduced a new concept, namely the limited random walk; and found out the formula of the ordered aperture angle for which the values of coherent factor take from N2 to N. This formula has shown that the angle is inversely propertional to the dimension of random array, but is indeperdent of the total number of random points, and that the angle is several times as large as that of the power spectra of regular array in the same domain.
1992, 41 (12): 1961-1967. doi: 10.7498/aps.41.1961
The general optical transformation theory is used for the design for converting Gaussian laser beam into a uniform profile. The transformation system can be achieved with two phase-only masks system. The phase-only mask may be fabricated with reactive ion-etching on a quartz plate. Experimenra) results indicate that the output beam profile is consistent with the theoretical calculation. The conversion efficiency is higher than 95%.
CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
By using electron diffraction method, three new vacancy ordered phases, τ23,τ27 and τ35, have been found in the conventionally solidified Al65Cu20Co15 alloy. They do not belong to the known Fibonacci series The computed kinematical intensities shown that the stacking sequences of τ23,τ27 and τ35 are respectively 332323232, 3323323323 and 3323323323323.
DEGENERACIES OF THE ELECTRONIC AND PHONON STATES OF THE TWO-DIMENSIONAL QUASICRYSTALS WITH N-FOLD ROTATIONAL SYMMETRY
1992, 41 (12): 1972-1979. doi: 10.7498/aps.41.1972
The similarity transformation is introduced which reduce the hamiltonian and the dynamical matrix of the two-dimensional quasicrystals with A/-fold rotational symmetry. For the degeneracy, when N is even number, N-2 out of N+2 of electronic and phonon states are doubly degenerate and 4 out of N+ 2 are non-degenerate, and as N is odd number, N-1 out of N+1 of electronic and phonon states are doubly degenerate and 2 out of N+1 are nondegene-rate. We use group theory +o study the degeneracies of twodimensional quasicrystals and obtain the same conclusion.
1992, 41 (12): 1980-1986. doi: 10.7498/aps.41.1980
A vector expression of the dilatotion field of a segment of dislocation line was obtained with isotropic elasticity. The interaction potential field between a geometric kink, made of straight segments or a smooth curve of dislocation, and a point defect was thus obtained. The distribution of the potential along the dislocation tube for different types and widths of kink was calculated numerically.The possibility of the dislocation relaxation associated with the interaction between a mobile vacancy and the geometric kink on screw and mixed dislocations was analysed.
DEFECT OF SYMMETRY OF THE TIME-MEAN-INTERACTION-FIELD BETWEEN AN OSCILLATING KINK AND POINT DEFECT AND SELF-ORGANIZATION PHENOMENON
1992, 41 (12): 1987-1992. doi: 10.7498/aps.41.1987
The elastic interaction force field and rigidity field between kinds on screw dislocation and a substitutional foreign atom were calculated with isotropic elastical approximation.The time-mean-interaction-potential of a harmonic oscillating kink along the tube of the screw dislocation was calculated. There appeared a defect of symmetry of the mean potential at the amplitude larger than a critical amplitude. Double peaks of potential instead of a single peak occured. The center of the kink turned the lowest energy position for the substitutional atom into an instable position.The range of parameters in favor of the transition of the diffusional self-organization along the tube of screw dislocation, to form an atmosphere with double maximums of concentration, aud of the harmonic oscillation to flip-flop of the kink was estimated.
1992, 41 (12): 1993-2002. doi: 10.7498/aps.41.1993
The effects of quasi-hydrostatic pressure treatments on the Bi-system superconductors were investigated The cold-pressing treatments seriously weakened the inter-granular weaklinks and induced a large number of intragranular defects, resulting in the deterioration of the suprcon-ducting properties. The targe increase in the bulk density and the orientation of the superconducting grains were also observed in the cold-pressed samples. These drastic changes of superconductivity were mainly due to the shear stress under quasi-hydrostatic pressure. The post annealing treatments greatly enhanced the weaklinks and caused the partial recovery and the agglomeration of some defects. By coldpressing-annealing method, Jc (77 K, zero field) was raised to about 1600A/cm2. The pressure dependence of Tc under hydrostatic pressure was also investigated and dTc/dp was found to be 1.4K/GPa.
1992, 41 (12): 2003-2007. doi: 10.7498/aps.41.2003
The formula of the Molien function in the case of corepresentation is derived by application of the symmetry theory for second order phase transition to magnetic systems, it is different from that of unitary groups. The analysis of the magnetic phase transition of FeRh alloy shows that eqivalent representation in the sense of corepresentation may lead to different symmetry breaking for the reason of none-quivalent characters. The result that a continuous magnetic phase transition Oh1⊕θOh1→C4v1⊕θ[D4h1-C4v1] exists theoretically is supported by experiments.
CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
1992, 41 (12): 2008-2015. doi: 10.7498/aps.41.2008
Under the condition of qc?ω, the generalized frequency dispersion relation of polar pho-nons is simplified- The generalized Kurosawa relation and LST relation are derived and verified by the Raman spectra of TGS singal crystal.
1992, 41 (12): 2016-2023. doi: 10.7498/aps.41.2016
The interaction between electrons and acoustic lattice vibrations is investigated by the method of coherent states, giving out the solutions of solitons which can travel with subsonic or supersonic velocities. The form and energy of the solitons is given.
GROWTH OF 2223 PHASE IN Bi1.92Pb0.32Sr2Ca1.7Mg0.3Cu3.07Ox SUPERCONDUCTOR IN THE PROCESS OF SOLID STATE REACTION
1992, 41 (12): 2024-2033. doi: 10.7498/aps.41.2024
Samples with nominal composition Bi1.92Pb0.32Sr2Ca1.7Mg0.3Cu3.07Ox were synthesized by solid state reaction. The results of XRD, SEM, EDAX and ac susceptibility measurement on the block and the power samples showed that in the samples there coexisted the 110K and 85K superconducting phases. The 2223 phase (110K) is considered to form at first at boundaries and in the outer region of the crystals of the 2212 phase (85K). We also believe that the origin of the structure of 2223 phase may initally exist in the 2212 phase grains and dact ad certain kind of stacking faults, and the 2223 phase finally forms and grows through the intercalation of the CaCuO2 layers in the crystal lattice of the 2212 phase together with climbing of dislocations. A calculation pased on experimental data supports this point of view.
HIDDEN LOCAL GAUGE INVARIANCE IN FATEEV-ZAMOLO-DCHIKOV QUANTUM SPIN CHAIN UNDER OPEN BOUNDARY CONDITIONS
1992, 41 (12): 2034-2042. doi: 10.7498/aps.41.2034
Hidden local gauge invariance in Fatteev-Zamolodchikov quantum spin chain under open bondary conditions is studied in the framework of quantum inverse scattering method (QISM). Our results show that the Hamiltonian and its eigenvectors are explicitly gauge-dependent while the energy eigenvalues and the Bethe equations are gauge-invariant.
1992, 41 (12): 2043-2048. doi: 10.7498/aps.41.2043
A microwave magnetic resonance experiment has been performed on the spinel system CoxZn1-x(FeyCr1-y)2O4 in the reentrant spin glass region (0.4≤x≤0.8, y = 0.5, 0.8). The temperatue dependence of the line shape, linewidth, resonant field, g-factor, and the relationship of the linewidth to the concentration of magnetic ions have been studied. The mechanism of the experimental phenomena has been discussed using the spin clustering effect and the local random field model. The microwave magnetic resonance properties in the system can be attributed to the formation of spin clusters, the establishment of the long-range ferrimagnetic order, the collapse of the ferrimagnetic order and random freezing of spin clusters.
1992, 41 (12): 2049-2054. doi: 10.7498/aps.41.2049
A simple method for the analysis of concentration ratios N/Si and O/Si in SiNx/Si and SiOx/Si is presented. 1.95 MeV H beam elastic backscattering was used to determine the composition and thickness. A comparison with 2.1 MeV He beam Rutherford backscsttering (RBS) is given. It provides a complementary analysis technique. A brief discussion on results is given.
INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY
INVESTIGATION ON THE PHYSICAL PROPERTIES AND DEFECTS OF Cd2SnO4 FILMS DEPOSITED BY RF REACTIVE SPUTTERING
1992, 41 (12): 2055-2060. doi: 10.7498/aps.41.2055
Transparent conductiong films of cadmium-tin oxide were prepared by rf reactive sputtering from a Cd-Sn alloy target in an Ar-O2 atmosphere. The structure of the films was examined by X-ray diffraction. The electrical and optical properties of the films were found to depend on the oxygen concentration in the gas mixture and the substrate temperature as well as the post-deposition heat treatment. The lowest resistivity obtained was 1.74×10-6Ω·cm and the highest optical transmission was 95% over the visible region. For the films deposited at substrate temperature of 400℃ in an Ar-O2 atmosphere of 6% O2, heat treatment increased the optical gap energy from 2.37eV to 2.64eV.