Vol. 39, No. 5 (1990)
1990-03-05
GENERAL
1990, 39 (5): 677-684.
doi: 10.7498/aps.39.677
Abstract +
The fundamental equations and results of different methods for solving soliton equations are deduced by using the projection matrix method. A simple and unified discription of the-relations between these methods is presented.
1990, 39 (5): 685-692.
doi: 10.7498/aps.39.685
Abstract +
Starting from calculating the directivity pattern of bar-shaped gravitational wave antenna, the relation of position between gravitational waves detectors and source is discussed in this paper. Further, the methods, which is used to determine the position of gravitational wave source, based on the data of coincident experiments, and the position of continuous gravitational wave source, based on the data of single gravitational wave antenna, are obtained. These results are also applicable for other types of one-dimentional gravitational wave detector. Once the sensitivity of the gravitational wave detector reaches the level, enough to determine the intensity of gravitational wave, the results presented in this paper will undoubtedly be useful for gravitational wave astronomy in the future.
1990, 39 (5): 693-698.
doi: 10.7498/aps.39.693
Abstract +
The compression experiments with neon-filled microballoons were performed using Shen-guang (1012 W) neodymium glass laser facility. The results showed that the laser-driven implosion compression ratio was about 70, the electron density reached 1023 cm-3, the averaged implosion velocity was about 3.3×107 cm/s.
THE PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
1990, 39 (5): 699-706.
doi: 10.7498/aps.39.699
Abstract +
The bound state wave functions and energy levels of the system of charged fe-rmion and abelian dyon are obtained for the dyon charge Zd dc and the totai angular momentum j≥│q│+1/2. The transition matrix elements of this system in an external electro-magnetic field, are calculated, and corresponding selection rules are obtained. In particular, it is found that the electric dipole transition △j=0 exists, which is different from hydrogen-like atom and violates the parity conservation.
NUCLEAR PHYSICS
1990, 39 (5): 707-713.
doi: 10.7498/aps.39.707
Abstract +
Based on a simple energy density and with the help of lowtemperature expansion of Fermi-Dirac integrals, an analytical nuclear equation of state (EOS) P(s, ρ) is obtained. Under the assumption of adiabatic approximation, the time evolution of several hot/compressed nuclei are studied within the hydrodynamical framework. The critical condition of multifragmenta-tion is Particularly analysed.
ATOMIC AND MOLECULAR PHYSICS
1990, 39 (5): 714-717.
doi: 10.7498/aps.39.714
Abstract +
The molten structure of Na2O·B2O3 glasses are investigated by the temperature-dependent 11B CW-NMR technique. The results show that, as R≤0.5 there are two stable configurations in the molten state. One configuration, occuring at 730-780℃, has two bridge-oxygen atoms between two boron atoms; and the other configuration, occuring at 880-920℃, has three bridge-atoms between two boron atoms. But only the first configuration exists as R>0.5.
1990, 39 (5): 718-725.
doi: 10.7498/aps.39.718
Abstract +
Collision-induced dissociation dynamic processes have been studied in this paper by using Time-dependnet quantum mechanical perturbation theory. The molecular systems are of the type of the Morse oscillator and the intermolecular exponential repulsive interaction potential. The analytical formula established can be conveniently applied to analyse a variety of physical and chemical problems relevent to CID processes. The numerical calculation for the (I2, He) system shows that vibrational energy is more effective than translational energy in enhancing the rate of the CID processes, as the total energy of the system is fixed. In addition, except the energy barrier, there are no extra dynamical restrictions for CID processes.
1990, 39 (5): 726-734.
doi: 10.7498/aps.39.726
Abstract +
This paper covers our recent study of the quenching processes of I2(B3Πo+u) at high vi-brational level v′= 62. In the experiments, quenching rate constants of I2* with itself and with other molecules (He, Ar, Kr, H2, CO, N2, O2, CH4, NH3, C2H6) were determined, and it was found that in the collision process of I2* and NH3, the formation of the metastable complex (I2*…NH3) might be one of the major processes for fluorescence quenching. The quenching efficiency of the polar molecule, CO, is larger than other molecules, such as the :isoelectronic molecule, N2, showing that intermolecular dipole-induced dipole interaction may play an important role in enhancing the molecular quenching. More important, the theory for collision-induced dissociation (CID) proposed in paper 1 can satisfactorily model the experimental results, indicating strongly that in such high vibrational level, collision-induced direct dissociation is the dominant path.
CLASSICAL AREA OF PHENOMENOLOGY
1990, 39 (5): 735-740.
doi: 10.7498/aps.39.735
Abstract +
Starting from the joint statistics of the orthogonal components of the broadband thermal light viberation, which are normal to the propagation direction of light wave, we derive the concept of polarization degree and the joint probability density functions of those two orthogonal components in various polarization states, so that an overall description of polarization of the broadband thermal light is obtained.
1990, 39 (5): 741-748.
doi: 10.7498/aps.39.741
Abstract +
The amplitude film-grain noises are the important noises in white-light optical processing system. Their appearance gives a low output SNR. This is mainly influenced by the filtering process in Fourier plane and the low diffraction efficiency of the encoding grating.
1990, 39 (5): 749-753.
doi: 10.7498/aps.39.749
Abstract +
In this paper, we analyze optical realization of the 2-D Mellin transform, and propose a new method to perform the transform. The 2-D Mellin transform experiment is carried out, and the experimental results are given.
1990, 39 (5): 754-763.
doi: 10.7498/aps.39.754
Abstract +
A large number of Ti atoms populated mainly on the ground state (a3F2) and metastable states (a3F3,4) were produced by UV-laser (259-300 nm) photodissociation of TiCl4. Many stimulated Raman scattering lines and stimulated radiations of Ti atoms were observed by pumping Ti atoms on the a3F2,3,4 states via nearly resonant transitions. All the lines observed were assigned. The pulse duration and timeresolved spectrum of SRS of Ti atoms shows the photolysis of TiCl4 to Ti atom was very fast, and the time estimated for it was less than Ins.
PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
1990, 39 (5): 764-769.
doi: 10.7498/aps.39.764
Abstract +
The spectral and spatial characteristics of X-ray emission (5-200?) along or off the axis of the plasma column, produced by 1.06 μm laser beam irradiating luminum flat target in line focused configurations with an average power density 2×1012W/cm2, are studied by using a pinhole transmission grating spectrograph (PTGS). Problems for the plasma as an X-ray-laser gain medium are also discussed.
CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
1990, 39 (5): 770-777.
doi: 10.7498/aps.39.770
Abstract +
A lamellar X-ray dynamic diffraction theory of the surface distorted crystals and the simulation method for obtaining information in distorted layers are presented. Influence of different double crystals' arrangement upon rocking curves(RCs) and simulation procedure are, disscussed. The relation between RCs and the depth distributions of strain and damage in distorted crystals is analysed. As an example, the simulation results of the B+ implanted Si(l00) wafers are given.
1990, 39 (5): 778-781.
doi: 10.7498/aps.39.778
Abstract +
The transformation between Taupin's and Takagi's equations of X-ray dynamical theory in the case of distorted crystal is investigated. The physical implication of this transformation is presented. It is considered that the difference between these two quations is due to the different choice of the wave vector k0 but the function of these two equations is equivalent.
1990, 39 (5): 782-787.
doi: 10.7498/aps.39.782
Abstract +
Using the X-ray dynamical theory, the reflection coefficients of X-ray double crystal diffraction in Bragg case were derived. The results of the rocking curves calculated for different kind of crystals and different diffractions show that the peak value and the integral intensity of rocking curve for σ polarization are higher than those for π polarization. And the full width at half maximum (FWHM) of σ polarization is wider than that of π polarization. It is pointed out that when the incident X-ray beam is a circle polarized one or/and the crystals A and B are different kind of crystals or/and the diffraction vector of A is different from that of B, the approximative expression of the FWHM of rocking curve for double crystal diffraction, 21/2∞, which was used by many authors, is invalid.
1990, 39 (5): 788-792.
doi: 10.7498/aps.39.788
Abstract +
The permanent magnetic alloy Ce1+εFe4B4(ε= 0.1, B-rich phase) is studied by means of electron diffraction and high resolution electron microscopy. It has been determined that the Ce1+εFe4B4 alloy has a one-dimensional incommensurate modulated structure of Chimney-Ladder type consisting of two overlapped substructures fomed by Ce atoms and Fe-B clusters respectively. The unit cell parameters of Ce substructure are a = 7.08?, cCe= 3.51-3.60?, and the possible space groups are I4,I4,I4mm, I4/m, I4/mmm. The unit cell parameters of Fe-B substructure are a = 7.08?, cFe= 3.91?, and the space group is P/42/mcm. All of the major and satellite diffraction spots are indexed by using of four indexes method. The high resolution electron microscopic image shows contrast modulation bands corresponding to the modulated structure. The fluctuation of the period of Ce substructure has been observed and discussed. The orientational anormaly caused by the possible deviation of Ce atomic planes from the (a, b) plane is also discused.
1990, 39 (5): 793-801.
doi: 10.7498/aps.39.793
Abstract +
The glass forming-region of the Cul-Cu2O-WO3-P2O3 system with Cul content being 30 mol% is given. The ac conductivity of the specimens is measured. The relation between conductivity and WO3 content is determined. The structure of this system is studied by IR spectra, complex impedance diagrams, RDF and SEM. The relation between the electrial properties and the structure is discussed.
1990, 39 (5): 802-808.
doi: 10.7498/aps.39.802
Abstract +
For the vibrational spectra of trans-(CH)x and Cis-(CH)x, in the region of weak electron-lattice coupling λ, the λ-dependences of optical phonons ω0(k = O) of these two isomers obey different rules. This is due to the existence of 3 confined potential barrier in the cis-(CH)x and thus causes the ground state to be non-degenerate.
1990, 39 (5): 809-813.
doi: 10.7498/aps.39.809
Abstract +
A series of studies were conducted for surface valency in blue tungsten oxides by using pho-toemission technique. Rusults show that, the blue tungsten oxide contains not only one kind of valency, but conbination of two valences, namely the conbination of W+5 and W+6, and also the process of argon ion eching and high temperature treatment all induce the loss of oxygen in W-chemical reduction process, which causes W transfer from high valence to low valence. Meanwhile, the density of state near Fermi level increases with the change from high valence to low valence.
CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
1990, 39 (5): 814-822.
doi: 10.7498/aps.39.814
Abstract +
The method of the harmonic oscillator operator algebra has been used to study the two-dimensional polaron in a magnetic field. Both the surface optical phonon and the surface acoustic phonon, and their interaction with the magnetic field are included. Ground-state energy corrections up to fourth-order perturbation for limiting cases of strdng field and that in second-order perturbation for field of arbitrary strength are derived. It is found that the surface acoustic phonon makes a significant contribution to ground-state energy of a two-dimensional polaron in magnetic field.
1990, 39 (5): 823-829.
doi: 10.7498/aps.39.823
Abstract +
On the basis of Ref. [1] , we analyse the sub-steps of I-V characteristics in Josephson junction theoretically. Firstly, a mathematical method is developed, then the conditions of existence of sub-steps are obtained by that method. Our results make the discussion for I-V characteristics in Josephson junction perfect.
1990, 39 (5): 830-835.
doi: 10.7498/aps.39.830
Abstract +
Flux creep in high Tc oxide YBa2Cu3Oy superconductor in critical state has been studied by observing variation of magnetization with time. Experimental results show that for the zero field cooling sample, the magnetization decays with time following the law M∝lnt over the observation time period, and this process accompanies by the occurrence of flux jumps. The rate of the magnetization decay dM/dlnt, as a function of the field, exhibits a maximum near H=3HP. It is believed to be related to weak link superconductivity. dM/dlnt decreases monoto-neously with the rising temperature in the temperature range above 77K. Finally, a discussion is made about the activation energy of the flux lines U0.
INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY
1990, 39 (5): 836-842.
doi: 10.7498/aps.39.836
Abstract +
Undercooling experiments of Pd43.5Ni43.5P13 and Pd40Ni40P20 alloys were performed in a 1.2 m drop tube. The effect of cooling rates on the glass formation, nucleation and crystal growth of the Pd40Ni40P20, alloy was studied by filling the various inert gas in the tube. The critical cooling rate for the glass formation in the tube was determined. In addition, it is indicated that the initial temperature of the drop before it droped down is related closely to the nucleation and crystal growth of the alloy.
