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Vol. 39, No. 1 (1990)

1990-01-05
GENERAL
AN ANALYSIS OF THE CRITICAL PHASE TRANSITION PHENOMENA OF ONE-DIMENSION PROBABILITY CELLULAR AUTOMATA EVOLUTION
Lü XIAO-YANG, KONG LING-JIANG, CHEN GUANG-ZHI
1990, 39 (1): 1-9. doi: 10.7498/aps.39.1
Abstract +
The dynamic equation of one-dimension probability cellular automata evolution is studied by means of real space renormalization group method. The phase transition phenomena in the cellular automata evolution are observed. The probability parameters at the critical point take values P0= 0, and P1 = P2 = 0.5. The critical index z = 2. A large number of data are obtained with computer.
"CORE RING-RATIO" METHOD FOR SURFACE ROUGHNESS MEASUREMENT WITH INCOHERENT LIGHT SOURCE
CHENG LU, SIU GUEI-GU
1990, 39 (1): 10-17. doi: 10.7498/aps.39.10
Abstract +
This work extends the "Core-Ring-Ratio" method for surface roughness mea-surement[1-5] from the case using coherent light source to the case using incoherent source (i. e., extended non-monochromatic light source). The formulas of the principle of measurement and the schematic diagram of the measuring device are presented.
NUCLEAR PHYSICS
ISOVECTOR GIANT RESONANCES ON HOT NUCLEI
LI GUO-QIANG
1990, 39 (1): 18-23. doi: 10.7498/aps.39.18
Abstract +
The self-consistent semi-classical sum rale approach is utilized to study the properties of isovector giant resonances on hot nuclei. The temperature effect on the average excitation energies of isovector GMR, GDR and GQR are evaluated with extended Skyrme forces.
SELF-CONSISTENT SEMI-CLASSICAL APPROACH FOR ANALYSING THE TEMPERATURE EFFECT ON NUCLEON MEAN FREE PATH
SHI JIAN-QING, LI GUO-QIANG, GAO QIN
1990, 39 (1): 24-29. doi: 10.7498/aps.39.24
Abstract +
The effect of temperature on the nucleon mean free path is analysed by utilizing the nac-leon density ρq, determined by self-consistent semi-classical approach and the optical potential obtained in local density approximation
EXPERIMENTAL VERIFICATION OF THE 11.528MeV STATE IN 24Mg
SHI DE-TANG, GUO ZHEN-DI, YANG FU-JIA
1990, 39 (1): 158-162. doi: 10.7498/aps.39.158
Abstract +
This work gives the experimental verification about the existence of the 11.528 MeV state in 24Mg which was newly discovered with the recoil-coincident technique in HI reaction. Resonant γ-ray absorption method has been used. Several dips have been observed in the resonance absorption transmission curve and recognized to be the fine structure around the 11.528 MeV excited energy level. The excitation energy and level width were deduced for each sub-level and the total width of energy level 13.321 MeV in emitting nucleus 28Si was also obtained from data fitting procedures.
ATOMIC AND MOLECULAR PHYSICS
POWER BROADENING OF PHOTOEMISSION SPECTRA IN STRONG FIELD AUTOIONIZATION
XU ZHI-ZHAN, YAO GUAN-HUA, QU WEI-XING
1990, 39 (1): 30-34. doi: 10.7498/aps.39.30
Abstract +
Photoionizing decay of the autoionizing state is taken into account in the model of strong laser field induced autoionization. Photoemiss ion spectra are recalculated and significant power broadening of these spectra is found, which is in contrast with previous predictions using. simpler model.
ABOVE-THRESHOLD IONIZAT1ON BY A SMOOTH LASER PULSE
YU WEI, XU ZHI-ZHAN, YAO GUAN-HUA, CHENG RONG-QING
1990, 39 (1): 35-39. doi: 10.7498/aps.39.35
Abstract +
In this paper, using "essential states model" we present an non-perturbative analysis of above-threshold ionization by a Gaussian laser pulse, and discuss the time evolution of its characteristic electron spectra.
ANGULAR DISTRIBUTION OF ABOVE-THRESHOLD IONIZATION OF H ATOM
CHEN BAO-ZHEN
1990, 39 (1): 40-45. doi: 10.7498/aps.39.40
Abstract +
With a model theory we analyse the recenl experiment on the angular distribution of above-threshold ionization of H-atom, and show some rules of the angular distribution. We also discuss the shortcoming of the ordinary perturbation theory in brief.
TEM INVESTIGATION ON SILVER SOLS AFTER ADDITION OF KCl
WANG WEI-NING, NI DONG-HAI, FANG YAN, FU SHI-YOU, ZHANG PENG-XIANG
1990, 39 (1): 46-50. doi: 10.7498/aps.39.46
Abstract +
The influence of adding KCI on the silver sols was studied by transmission electron microscopy (TEM). It was found that the Ag atoms on the surfaces of the colloidal silver particles were transported to other positions of the silver surfaces after adding KCI, and the sur-feccs of colloidal silver particles were covered with an atomic group layer which had some kind of structure. At the same time, a chain-like colloidal aggregation in Ag sols was induced by KCI. This was compared with the case of adding pyridine. Also we discussed the effect of adding KCI on the SERS signals of molecules adsorbed on colloidal silver particles.
STRONG RADIAL-RADIAL CORRELATION REGION IN DOUBLY EXCITED 1Se STATES OF HELIUM ATOM
BAO CHENG-GUANG
1990, 39 (1): 163-166. doi: 10.7498/aps.39.163
Abstract +
The electron-electron correlation in the N=3 series of the 1Se helium states has been investigated in detail. The geometric implication of the K-classification scheme has been recognized. The strong radial-radial correlation region where the radial motions of the two electrons are, coupled strongly in inverse phase has been discovered.
CLASSICAL AREA OF PHENOMENOLOGY
ORTHONORMALIZED EIGENSTATES OF OPERATOR αN AND THEIR PROPERTIES
PENG SHI-AN, GUO GUANG-CAN
1990, 39 (1): 51-60. doi: 10.7498/aps.39.51
Abstract +
In this paper, a general method for constructing orthonormalized eigenstates of operator αN is presented. The emphasis is put on study of mathematical structure and quantum statistical properties in the case N=3. It is found that all the orthonorma-lizetl eigenstates have nonclassical effects and they form a nonclassical complete representation.
A STIMULATED TRANSITION RADIATION OPTICAL KLYSTRON
JIANG HUA-BEI
1990, 39 (1): 61-66. doi: 10.7498/aps.39.61
Abstract +
A new scheme of an optical klystron based on stimulated transition radiation is proposed.Calculations on spontaneous and stimulated emission are made for such a device using Madey's theorem in free electron lasers (FEL). The analysis in this paper shows that Madey's theoremcan really simplify the calculations and give clear physical concepts. The case of N mediumsections cascaded through magnetic field dispersive sections is also discussed.
OPTICAL PHASE CONJUGATION BY STIMULATED BRILLOU-IN SCATTERING IN THE PRESENCE OF SELF-FOCUSING
HUANG YONG, GONG QI-HUANG, YANG JIA-SUN
1990, 39 (1): 67-75. doi: 10.7498/aps.39.67
Abstract +
Phase conjugation with high quality can be obtained by stimulated Brillouin scattering in the focused beams' scheme, even when the in homogeneous pump light contains a self-focusing strong component. The scattered light originates from the selftrapped filament regions. The conjugation fraction η depends on the intensi ty ratio a of the strong component and the total incident light, attaining a maximum ηmax (=80%) at a certain value of σ. By taking in-tc account the effect of self-focusing on η(σ), a fair agreement with experiments is obtained.
TWO-PHOTON PUMPEL SIX-AND FOUR-WAVE MIXING AND STIMULATED RADIATION IN LITHIUM VAPOR
WANG ZU-GENG
1990, 39 (1): 76-81. doi: 10.7498/aps.39.76
Abstract +
This paper reports the generation of the coherent and stimulated radiation in UV, visible and infrared regions by two-photon pumping. It includes the tunable coherent radiation around 1.03 μm generated by a special six-wave mixing process, the stimulated radiation at 812.6 nm generated by molecular two-photon dissociation or atomic cascade transition, coherent radiation at 323.3 nm and 670.8 nm generated by the four-wave mixings.
EFFECTS OF HYDROGEN ATMOSPHERE ON LOSS CHARAC-TERISTICS OF OPTICAL FIBER
NING DING, HU KAI-SHENG, FU HUAI-JIE
1990, 39 (1): 82-88. doi: 10.7498/aps.39.82
Abstract +
Spectrum attenuation changes for MCVD optical fiber exposed to a hydrogen atmosphere at 100, 130, 150 and 180℃ are measured. The loss increases at 1.24 μm and 1.41μm due to molecular hydrogen and hydroxyl respectively are investigated. The empirical formula for time and temperature dependence of the loss increase are obtained from the experimental results. The loss increase at 1.3 μm and 1.55μm, at room temperature are estimated.
REFLECTION OF AND REFRACTION OF FINITE AMPLITUDE SOUND WAVE ON PLANE BOUNDARY OF HALF SPACE
ZHENG XIAO-YU, QIAN ZU-WEN
1990, 39 (1): 89-93. doi: 10.7498/aps.39.89
Abstract +
Based on the theory of reference [1] , a further investigation of the reflection and refraction of finite amplitute sound waves on a plane boundary between two media is made, and a solution of the refracted sound field in the second medium is obtained. Some problems about boundary condition and refraction law are analysed.
PHYSICS OF GASES, PLASMAS, AND ELECTRIC DISCHARGES
TEST PARTICLE DIFFUSION ACROSS A SINGLE ISLAND IN A TOKAMAK
A. J. WOOTTON, ZHENG SHAO-BAI
1990, 39 (1): 94-100. doi: 10.7498/aps.39.94
Abstract +
In this paper, the phenomena of a test particle diffusion near a single magnetic island in a Tokamak is investigated by the method of Monte Carlo and an effective diffusion time is used to describe the effect of diffusion by the island quantitatively. The results show that there is a uniform function between effective diffusion time and a value called collision raie. The relationsipe between the effective diffusion time and the collision rate and the particle density distribution inside and near the islnad are calculated.
CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES
THE APPLICATION OF ∑ RELATIONSHIP LINEAR THEORY (Ⅲ)——ON ESTIMATING ±π/2 TYPE OF PHASE
LIU YONG-SHENG, HU NING-HAI, JIN ZHONG-SHENG
1990, 39 (1): 101-110. doi: 10.7498/aps.39.101
Abstract +
We discuss the fundamental principle and application of estimating ±π/2 type of phase using ∑ relationship in noncentrosymmetrical crystal structures. We obtain an optimum coincident principle between specifying the origin of unit cell, enantiom-orph and estimating ±π/2 type of phase. A group of phases of this type is estimated by ∑7,∑3 relationships for two known crystal structures in terms of the above mentioned principle. The results are satisfactory.
SUBSTITUTION EFFECTS AND NEUTRON DIFFRACTION STUDY OF YBa2(Cu0.95M0.05)3O7-δ
YANG YING-CHANG, ZHA YUAN-BO, YUAN WEI-CHUN, YANG JI-LIAN, ZHANG BAI-SHENG, ZHOU HUI-MING, DING YONG-FAN, JIN LAN, YE CHUN-TANG
1990, 39 (1): 111-118. doi: 10.7498/aps.39.111
Abstract +
YBa2(Cu0.95M0.05)3O7-δ were identified as single phase with M = Ti, V, Cr, Mn, Fe, Co, N1, Cu and Zn. Substitution of Fe, Co, Ni and Zn for Cu makes Tc, decrease significantly, while at the same content, no distructuve effect on Tc was observed in the replacement of Cu with Ti, V, Cr and Mn. The site occupation of Ti, Mn, Fe and Co ions has been investigated by using neutron diffraction technique, and strong site preference for these ions were observed. Based on these results, the two diffrent Cu sites and their relationship to the superconductivity in YBa2Cu3O7-δ are discussed. The substitution effect for copper on magnetic properties in YBa2(Cu0.95M0.05)3O7-δ and the correlation between magnetic and superconduc-tiviting properties are reported.
EXPERIMENTAL STUDIES ON O2- IN KCl:OH-
CHEN LUAN, YANG BAI-RUI, ZHANG LIN
1990, 39 (1): 119-123. doi: 10.7498/aps.39.119
Abstract +
It is identified by the modulated optical absorption spectra and ESR spectra that the main form of the oxygen components in KC1:OH- is O2-. The density of O2- in the sample increases with the increasing of the irradiation time until the(OH)- ions are completely destroyed by irradiation. O2- is a very stable radical,but no direct effects on the stability of F2+ centers are detected. The energy configuration of O2- is also discussed according to the ESR data.
SIMULATION STUDY OF DIVERGENT BEAM X-RAY DIFFRACTION BY CRYSTALS
ZHANG JIAN-ZHONG, CAO YAN-NI
1990, 39 (1): 124-128. doi: 10.7498/aps.39.124
Abstract +
Acoording to the crystal symmetry, diffraction geometry and the diffraction laws, the complicated divergent beam X-ray diffraction has been studied. A method for simulating such diffraction is described. The computer generated pseudo-Kossel line patterns are exactly consistent with those recorded in experiment and the indices of all diffraction lines in the patterns can be identified. A set of standard divergent diffraction diagrams related to 〈100〉, 〈110〉 and 〈111〉oriented Si single crystals are completed successfully by computer.
FORMATION AND CRYSTALLIZATION MECHANISM OF GLASSES IN NaBO2-B2O3 SYSTEM
FANG CHANG-MING, HUANG QING-ZHEN, LIANG JING-KUI
1990, 39 (1): 129-137. doi: 10.7498/aps.39.129
Abstract +
The formation, thermal stability and crystallization mechanism of glasses in NaBO2-B2O3 system have been studied by means of thermal analysis, X-ray powder diffraction at high and room temperatures, and IR absorption spectra. The stable glasses are formed easily in this system. The crystallization processes are related to macroscopic state of samples. The crystallization temperature of bulk glasses is higher than that of amorphous powders. A part of components crystallizes as different phases. They melt directly at different temperatures. The crystal structure of crystallization products is close to glass structure.The ionic conductivity in NaBO2-B2O3 system was determined by ac impedance method. The conductivity of glasses are 2-3 orders higher than that of crystals with the same composition, while the activation energy of glasses lower than that of crystalline state for the same composition.
SYNTHESIS AND PHYSICAL PROPERTIES OF INTERCALA-TION COMPOUND LiVO2
LIU ZAI-HAI, GAO JING-ZHI, ZHANG WEN-BIN, WANG GANG
1990, 39 (1): 138-142. doi: 10.7498/aps.39.138
Abstract +
The intercalation compound LiVO2 is synthesized successfully by use of solid reaction method. The experiments for composition proponion, X-ray powder diffraction and quantitative element analysis are made. Finally, the experimental results are discussed.
CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES
MAGNETIC AND ELECTRICAL PROPERTIES OF AMORPHOUS Fe86M4Zr10 ALLOYS
CHEN JIN-CHANG, LI DE-XIU, LI ZHI-QIANG, ZHAO JIAN-GAO, SHEN BAO-GEN
1990, 39 (1): 143-148. doi: 10.7498/aps.39.143
Abstract +
The magnetic and electrical properties of amorphous Fe86M4Zr10 (M = V, Cr, Mn, Fe, Co, Ni, Cu, B, Si) alloys are studied. Effects of M on the average magnetic moment and Curie temperature of these alloys are discussed. Electrical resistivity minimum in the vicinity of Tc is attributed to the coherent exchange scattering.
STRIPE DOMAIN LATTICE FMR IN GARNET THIN FILMS
BI SI-YUN
1990, 39 (1): 149-153. doi: 10.7498/aps.39.149
Abstract +
Dependence of the stripe domain lattice FMR on the orientation of the microwave exciting magnetic field is reported in detail. The present experimental results show that the Smit-Beljers' theory on domain lattice FMR is not perfect and needs to be improved further
THE SUPERCONDUCTIVITY, LATTICE PARAMETER AND THERMAL CHARACTERISTICS OF THE Yb-Ba-Cu(O, F) SYSTEM
ZHANG YU-LING, LIANG JING-KUI, RAO GUANG-HUI, CHENG XIANG-RONG, LI KE-SHENG, LEI LING, ZHENG DONG-NING, XIE SI-SHEN
1990, 39 (1): 154-157. doi: 10.7498/aps.39.154
Abstract +
Superconductive samples with compositions of YbBa2Cu3F2xO7-x-δ (0≤x≤1) have been prepared. The variations of Tc, lattice constants and cell volume with the fluorine dose have been described. We report an experimental observation of an increase of Tc with a decrease of the oxygen content in the YbBa2Cu3F2xO7-x-δ (0 ≤x≤1). Therefore with the content of oxygen increasing, the lattice constants and cell volume of the superconducter become larger. The higher Tc, the larger is the velue of lattice constants (b-a) of the orthorhombic structure. It has been shown that the M-Cu-O or Cu-O part of the systems may have an essential role or the superconductivity.