Acta Physica Sinica -

AN ASYMPTOTIC ANALYSIS OF THE TRAVELLING WAVE SOLUTION OF THE KdV BURGERS EQUATION

Lü XIAN-QING — 1992-01-05

Author(s): Lü XIAN-QING

By applying the theory and method of singular perturbations, we investigate the travelling wave solution of the KdVB equation under the assumption v2?4μ. We get the explicit expression of the travelling wave solution up to the third order atfirst. Then, we obtain the general asymptotic expansion: u=u(0)+εu(1)+ε1u(2)+…+εnu(n)+… and prove that u(j)(j=1,2,…,n,…) are bounded functions.

Acta Physica Sinica. 1992 41(2): 177-181. Published 1992-01-05

CONSERVATION LAWS OF THE VARIABLE COEFFICIENT KdV AND MKdV EQUATIONS

LOU SEN-YUE, RUAN HANG-YU — 1992-01-05

Author(s): LOU SEN-YUE, RUAN HANG-YU

In this paper, by using the Miura's method, we study the infinite conservation laws of the variable coefficient KdV and MKdV equations with three arbitrary functions of t. The result points out that the conserved densities which have the structures completely similar to the con-stat coefficient KdV and MKdV equations depend only on one arbitrary function. The other two arbitrary functions are contained only in the corresponding fluxes.

Acta Physica Sinica. 1992 41(2): 182-187. Published 1992-01-05

BACK REACTION IN VAIDYA-SCHWARZSCHILD-DE SITTER SPACE-TIME

DAI XIAN-XIN, ZHAO ZHENG — 1992-01-05

Author(s): DAI XIAN-XIN, ZHAO ZHENG

The back reaction in Vaidya-Schwarzschild-deSitter spacetime is discussed. It influences location and temperature of both the black-hole event horizon and the cosmological one.

Acta Physica Sinica. 1992 41(2): 188-192. Published 1992-01-05

DYNAMIC BEHAVIOR OF A TWO-TERMINAL ACTIVE NETWORK SYSTEM WITH NONLINEAR NEGATIVE RESISTANCE

PENG JIAN-HUA, XI YING, TIAN XIAO-JIAN — 1992-01-05

Author(s): PENG JIAN-HUA, XI YING, TIAN XIAO-JIAN

A numerical investigation has been carried out on a RLC series connection which is a two-terminal active network system with nonlinear negative resistance. It is found that within various parameter regions, a sequence of period doubling bifurcations, an inverse sequence of chaotic bands and an intermittant chaos phenomena appeared respectively. These results agree with our experimental ones very well.

Acta Physica Sinica. 1992 41(2): 193-200. Published 1992-01-05

INTEGRABLE QUANTUM CHAIN AND THE REPRESENTATION OF QUANTUM GROUP SUq(2)

HOU BO-YU, SHI KANG-JIE, YANG ZHONG-XIA, YUE RUI-HONG — 1992-01-05

Author(s): HOU BO-YU, SHI KANG-JIE, YANG ZHONG-XIA, YUE RUI-HONG

We discuss the XXZ spin chain with certain boundary term and the representation of quantum group SUq(2). It is shown that Bethe Ansatz states are highest weight states of SUq(2), with q arbitrary We construct the irreducible representation of the quantum group. For q a rational root of unity, we show that there are new solutions to the BA equations, We derived the state vectors | b′< by taking certain limit, from which we construct the type I and type Ⅱ representations of SUq(2).

Acta Physica Sinica. 1992 41(2): 201-212. Published 1992-01-05

PEIERLS MECHANISM OF HYDROGEN CHAIN (Ⅰ)——THE DIMERIZATION OF THE HARTREE-FOCK SOLUTIONS

FU RONG-TANG, SUN XIN — 1992-01-05

Author(s): FU RONG-TANG, SUN XIN

Ab initio study has been used to explore the problem if the Peierls instability in hydrogen chain presents or not. With a Gaussian-type-orbital basis set and periodicity of hydrogen chain, we construct a complete set of orthogonal and normalized wave functions in view of the second-neighbor approximation. Starting from the restricted Hartree-Fock scheme, we diagnoalize the Fock matrix analytically and calculate the LCAO-MO-SCF solutions. The dependence of the total energy on dimerization is analyzed, it is shown that the ground state of metal hydrogen chain is unstable, and that obvious dimerization may occur in infinite hydrogen chain. The Per erls instability presents in this system nevertheless.

Acta Physica Sinica. 1992 41(2): 213-220. Published 1992-01-05

PEIERLS MECHANISM OF HYDROGEN CHAIN (Ⅱ)——THE DEPENDENCE OF THE PEIERLS INSTABILITY ON THE ELECTRON CORRELATION

FU RONG-TANG, SUN XIN — 1992-01-05

Author(s): FU RONG-TANG, SUN XIN

We use the correlated basis functions method to explore the problem of the Pe-ierls instability due to the electron correlation in hydrogen chain. Our thory shows that the bond alternation is reduced from 0.37 (au) to 0.32 (au) by the electron correlation, but the Peierls instability survives under the electron-electron interaction.

Acta Physica Sinica. 1992 41(2): 221-227. Published 1992-01-05

HIGHLY CHARGED ION N6+ COLLISIONS WITH ATOM He INTO EXCITED STATES

1992-01-05

Author(s): PAN GUANG-YAN, YANG FENG, LI DA-WAN, LU ZHAN-WEN, ZHANG WEN, XU QIAN, LIU HUI-PING, ZHAO MENG-CHUN

The excitation processes in collisions between N6+ and He have been investigated by using the ECR ion source and the LHT-30 VUV Monochromator. The emission spectra shows that there are three channels of excitation in the N6+ and He collision system: (1) Single-electron capture into excited states. (2) Double-electron capture into excited states. (3) Direct excitation of indicident ions.

Acta Physica Sinica. 1992 41(2): 228-232. Published 1992-01-05

THEORY OF (e, 2e) COLLISIONS IN COMPLEX ATOMS

Qian Qing, Liu Qiang, Xu Xiang-dong, Tian Jia-he, Chen Xue-jun — 1992-01-05

Author(s): Qian Qing, Liu Qiang, Xu Xiang-dong, Tian Jia-he, Chen Xue-jun

The multiple-scattering expansion for (e, 2e) collisions in H-atoms is extended to the case of complex atoms.

Acta Physica Sinica. 1992 41(2): 233-237. Published 1992-01-05

DYNAMIC LASER SPECKLES PRODUCED BY DOUBLE LIGHT BEAMS

YAO KUN, XU GUANG-YU, GUO GUANG-CAN, PENG HU, ZHOU PEI-LING — 1992-01-05

Author(s): YAO KUN, XU GUANG-YU, GUO GUANG-CAN, PENG HU, ZHOU PEI-LING

In this paper we derive the time-space correlation funotion of dynamic speckles produced by double light beams. An experiment using photon correlation method is performed, the result accords well with the expectation of the present theory.

Acta Physica Sinica. 1992 41(2): 238-243. Published 1992-01-05

REFLECTION AND TRANSMISSION OF PICOSECOND SOLI-TON AT INTERFACE SEPARATING TWO MEDIA IN OPTICAL FIBER

CHEN LU-JUN, LIANG CHANG-HONG, WU HONG-SHI — 1992-01-05

Author(s): CHEN LU-JUN, LIANG CHANG-HONG, WU HONG-SHI

The governing equations and boundary conditions for reflection and transmission of picosecond soliton at the interface between two media in optical fiber is developed by radial mode averaging method with slowly varing envelope and quasi-monochromatic approximations. The proccess of reflection and transmission is numerically simulated by using beam-propagating method and some numerical examples are given.

Acta Physica Sinica. 1992 41(2): 244-252. Published 1992-01-05

EFFECT OF RELATIVISTIC HYSTERESIS ON RESONANCE ABSORPTION

MA JIN-XIU, SHENG ZHENG-MING, XU ZHI-ZHAN — 1992-01-05

Author(s): MA JIN-XIU, SHENG ZHENG-MING, XU ZHI-ZHAN

Using a simple model, it is shown that because of the relativistic electron-mass variation, the mode-converted electrostatic electric field exhibits hysteresis in the vicinity of critical layer. This hysteretic effect is to increase the resonance absorption of obliquely incident p-pola-rized light in a way by increasing the large amplitude region of the electrostatic field. When the threshold light intensity for the occurance of hysteresis is exceeded, the fractional absorption increases drastically above the linear results.

Acta Physica Sinica. 1992 41(2): 253-259. Published 1992-01-05

THEORY OF DEGENERATE AND NEARLY DEGENERATE FOUR-WAVE MIXING IN PLASMAS——IN THE CASE OF REFLECTION GRATING CONFIGURATION

WU YING, YANG XIAO-XUE — 1992-01-05

Author(s): WU YING, YANG XIAO-XUE

In this paper, the theory of degenerate and nearly degenerate four wave mixing in plasmas in reflection geometry is investigate. The universal set of four wave nonlinear coupled equations is obtained and its exact solution appropriate for arbitrary nonlinear coupling parameter is found.

Acta Physica Sinica. 1992 41(2): 260-266. Published 1992-01-05

BEHAVIOUR OF X-RAY DIFFRACTION FROM UNIFORMLY BENT Si CRYSTAL

YANG PING — 1992-01-05

Author(s): YANG PING

X-ray diffraction from uniformly bent Si crystal has been studied. The experimental integrated diffraction intensity rises monotonically with the strain in the crystal, this coincides with the theory. The visibility of Pendell?sung fringes becomes poorer as the strain goes up, this reflects the increse of intensity difference between the wave fields and variation of the trace of the wave fields in the crystal.

Acta Physica Sinica. 1992 41(2): 267-271. Published 1992-01-05

STUDY ON DISLOCATIONS IN LITHIUM BORIC OXIDE (LBO) CRYSTAL

ZHAO QING-LAN, HUANG YI-SEN, TANG DING-YUAN — 1992-01-05

Author(s): ZHAO QING-LAN, HUANG YI-SEN, TANG DING-YUAN

Dislocations in a new non-linear crystal, Lithium Boric Oxide(LBO), have been observed and identified by X-ray diffraction topography. The structural factor which plays important role on dislocations formation, the lattice expansion and twinned growth is given.

Acta Physica Sinica. 1992 41(2): 272-275. Published 1992-01-05

PRIMARY STUDY ON THE IRRADIATION EFFECT OF HYDROGEN IONS ON DIAMOND-LIKE CARBON FILMS

WANG TIAN-MIN, WANG WEI-JIE, HAN PEI-GANG, HUANG LIANG-FU, LUO CHONG-TAI — 1992-01-05

Author(s): WANG TIAN-MIN, WANG WEI-JIE, HAN PEI-GANG, HUANG LIANG-FU, LUO CHONG-TAI

Diamond-like carbon (DLC) films, prepared by dual-ion beam sputtering method on glass substrate, were irradiated by high energy hydrogen ions(H+) under different combinations of ion energy and irradiation dose. Raman spectroscopy, infra-red transmittance spectroscopy, electrical resistivity measurement and adhesive force determination were used to characterize the as-deposited and the irradiated films. The results showed that, comparing with that of as-deposited ones, the properties and structures of irradiated films were changed obviously: the infra-red transmittance in the range of 1450 to 6000 cm-1 was increased; the electrical resistivity had nearly no large change. The relative ratios of sp2 C-H bond to sp3 C-H bond and sp3 C-C bond to sp2 C-C bond were also increased, while the component of sp3 C-C bond and sp2 C-C bond was decreased because of H+ irradiation. On the basis of the above results., the relations between properties and structures for irradiation On the basis of the above results, the relations between properties and structures for irradiated films were discussed in detail between properties and structures for irradiated films were discussed in detail. It is concluded It is concluded that the H+ irradiation effect on DLC films is different from that of Cc or other heavier ions. The main role of H+ on the films is the teching effect on weaker bonds. We believe that it is possible to improve the properties of DLC films by means of high energy H+ irradiation.

Acta Physica Sinica. 1992 41(2): 276-281. Published 1992-01-05

FORMATION OF HOLOGRAPHIC DIFFRACTION GRATINGS ON THE SURFACE OF A n-TYPE Ga As AND MEASURING OF LIGHT EMISSION BY SURFACE PLASMON POLARITON

WU DlNG-XIANG — 1992-01-05

Author(s): WU DlNG-XIANG

The method to produce diffraction gratings by H2O2-H2SO4 photo-accelerated etching on the surface of n-GaAs and measuring of light emission by surface pla smon polariton from an Ag/n-GaAs Schottky barrier diode are discussed in this paper.

Acta Physica Sinica. 1992 41(2): 282-287. Published 1992-01-05

A STUDY ON THE 2% PdO/Al2O3 BY MEANS OF FREE POSITRON ANNIHILATION TECHNIQUE IN THE SOLID SURFACE LAYER

SHI ZHI-KANG, HUANG CUN-PING — 1992-01-05

Author(s): SHI ZHI-KANG, HUANG CUN-PING

In this work, we studied the relationship between heat treatment and space structure of the PdO layer in 2% PdO/AL2O3 by the positrons from 22Na radiative source, and calculated its grain size by the positron annihilation parameters, demonstrating that the free positron annihilation technique for the solid surface layer can be applied to catalyst research.

Acta Physica Sinica. 1992 41(2): 288-294. Published 1992-01-05

STRONG CHEMISORPTION AND DISSOCIATION OF N2 ON Cr(110) SURFACES

ZHOU RU-HONG, CAO PEI-LIN — 1992-01-05

Author(s): ZHOU RU-HONG, CAO PEI-LIN

An ASED-MO method has been applied to investigate the N2 chemisorption on Cr(110) surface. The results show that N2 chemisorbs parallelly on the 4-fold site with N-N axis parallel to [110] direction. Different from the tranditional σ-donation and π weak backbonding concepts, the N2 chemisorption on Cr(110) has both the 3 σg and 1 πμ donations of 0.97 and 0.54 electrons. At the same time, the backbonding to the 1 πg orbital increases to 1.83 electrons. Both these factors make the lying-down orientation being favored over the upright orientation. Furthermore, the N-N bond length strenches 17%, the N-N bond order decreases to below 1, and the dissociation barrier is only about 0.15 eV. All the above calculation results are in good agreement with relevant experiments.

Acta Physica Sinica. 1992 41(2): 295-301. Published 1992-01-05

INVESTIGATION ON THERMAL STABILITY OF REACTIVE- SPUTTERING a-Si:H/a-Ge:H SUPERLATTICES

WANG YIN-YUE, XU HUAI-ZHE, CHEN GUANG-HUA — 1992-01-05

Author(s): WANG YIN-YUE, XU HUAI-ZHE, CHEN GUANG-HUA

The thermal stability of a-Si:H/a-Ge:H superlattices was studied using LR and XRD spec tra. It was found that the crystallization temperature of superlattices with small layer thickness is higher than that of bulk a-Ge:H. Results are discussed preliminarily.

Acta Physica Sinica. 1992 41(2): 302-305. Published 1992-01-05

EFFECT OF ROUGHNESS OF MULTILAYER INTERFACE ON THE DOUBLE-CRYSTAL X-RAY DIFFRACTION ROCKING CURVES

OUYANG JI-TING, MAI ZHEN-HONG, CUI SHU-FAN — 1992-01-05

Author(s): OUYANG JI-TING, MAI ZHEN-HONG, CUI SHU-FAN

Based on X-ray dynamical theory, the double-crystal diffraction rocking curves for In-GaAs/InP single layer and InGaAs/AlInAs/InP superlattice were calculated for both perfect and rough interfaces. It is shown that the effect of roughness of multilayer interface on the zero-order diffraction peak was not obvious but severe on both the satellite peaks for superlattice and the interference fringes for single layer structure. With the increasing of the interface roughness, the intensities of interference fringes were reduced and disappeared. And for the satellite peaks, their intensities were reduced and the full width at half maximum broadened. Comparing the experimental result with the calculated one, we believe that there still exists an average roughness of about one monoatomic layer at the interface of high quality InGaAs/Al-InAs/InP lattice-match superlattice sample.

Acta Physica Sinica. 1992 41(2): 306-310. Published 1992-01-05

ALTERNATING CURRENT SUSCEPTIBILITY STUDIES OF Y-Ba-Cu-O (123) BULK MATERIAL PREPARED BY MELT-TEXTURED GROWTH METHOD

1992-01-05

Author(s): WANG SHUN-XI, WANG YU-GUI, CHEN XIANG-AI, YUAN SONG-LIU, ZHOU XIAN-YI, CAO LIE-ZHAO, ZHANG QI-RUI

The a.c. susceptibility of Y-Ba-Cu-O(123) bulk material prepared by melt-textured growth (MTG) method was studied and compared with that of sintered sample in this paper. The results show that there are two peaks in the imaginary part corresponding to the grains and grain boundaries in the sintered sample, but only one peak is observed in that of MTG sample of high quality. As for that of MTG sample of worse quality, also two peaks are observed, but they correspond to grains with different growth direction. No frequency effect is observed in both the sintered sample and the MTG sample, showing that the loss is related to flux motion.

Acta Physica Sinica. 1992 41(2): 311-316. Published 1992-01-05

MAGNETIZATION MEASUREMENT OF ANISOTROPIC CRITICAL CURRENT DENSITIES IN MELT TEXTURED YBa2Cu3O7-y

FAN HONG-CHANG, JIN XIN, LU MU, ZHANG YI-TONG, XU XIAO-NONG, YAO XI-XIAN — 1992-01-05

Author(s): FAN HONG-CHANG, JIN XIN, LU MU, ZHANG YI-TONG, XU XIAO-NONG, YAO XI-XIAN

Anisotropic critical current densities of melt textured YBa2Cu3O7-y superconductor were measured using d.c. magnetization measurements. Effcet of demagnetizing field was taken into account. A model appropriate to finite anisorropic samples was adopted and the method proposed recently by Gyorgy et al. was modified. We measured magnetization curves of a rectangular parallelepiped sample in magnetic fields parallel to different edges of the sample and obtained values of three different critical current densities.

Acta Physica Sinica. 1992 41(2): 317-322. Published 1992-01-05

INVESTIGATION ON FERROMAGNETIC PHASE IN THE 2-DIMENSION LARGE-U HUBBARD MODEL

LI DING-GUO, ZHENG RUI-LIN, HU LIAN — 1992-01-05

Author(s): LI DING-GUO, ZHENG RUI-LIN, HU LIAN

From Zou and Anderson's spinon-bolon effective Hamiltonian, for very large Coulomb repulsion U, we consider the problem of ferromagnetism on the square lattice by studying the fluctuation effect of bosons (holons).

Acta Physica Sinica. 1992 41(2): 323-328. Published 1992-01-05

ELECTRON SPIN RESONANCE STUDY ON RADIOLYTIC DAMAGE IN BaCl2 CRYSTALLITE

HOU BI-HUI, YANG BING-XIN, SHI CHAO-SHU, LIANG REN-YOU, LU XIAO-PU — 1992-01-05

Author(s): HOU BI-HUI, YANG BING-XIN, SHI CHAO-SHU, LIANG REN-YOU, LU XIAO-PU

The x-ray and γ-ray radiolytic damage in luminous host material BaCl2 and its recovery have been studied by the electron spin resonance method. It is found that the x-ray radiolytic damage in the sample can be recovered completely under sunlight for only two minutes, but the complete recovery of γ-ray damage is not easy.

Acta Physica Sinica. 1992 41(2): 329-332. Published 1992-01-05

A NEW THEORY AND EXPERIMENT ON ELECTRICAL AGING AND BREAKDOWN OF SOLID DIELECTRICS

LIU FU-DE, YANG BAI-TUN, TU DE-MIN, LIU YAO-NAN — 1992-01-05

Author(s): LIU FU-DE, YANG BAI-TUN, TU DE-MIN, LIU YAO-NAN

According to first-order capture equation, a kinetic theory for trap creation in solid dielectrics is proposed in this paper. Taking a certain trap density as critical condition of electrical breakdown, it is found that the dielectrical lifetime is proportional to the exponent of electrical strength. Such a theory is consistent with the widely used emperical formula and agrees with experimental results.

Acta Physica Sinica. 1992 41(2): 333-341. Published 1992-01-05

OPTICAL DIODE EFFECT INDUCED BY USING TWO LASER BEAMS IN Mn DOPED KNSBN CRYSTAL

1992-01-05

Author(s): SHE WEI-LONG, LI QING-XING, YU ZHEN-XIN, GAO ZHAO-LAN, ZHANG QING-LUN, CHEN HUAN-CHU

Two laser beams of wave length 632.8nm encouter in Mn doped KNSBN crystal and induce a optical diode. A maximum ratio of 202 for equivalent transmissivity in two directions of the optical diode is obtained at the input powers of 0.876mW and 0.0914mW respectivly and the ratio shows a tendency to increase further.

Acta Physica Sinica. 1992 41(2): 342-346. Published 1992-01-05

STUDIES ON MAGNETIC PROPERTIES OF FILM OF POLYANILINE

WAN MEI-XIANG, ZHOU WEI-XIA — 1992-01-05

Author(s): WAN MEI-XIANG, ZHOU WEI-XIA

The ESR single and magnetic properties of free standing film of polyaniline (PANI) have been measured as a function of elongation treatment and the protonation state. The results obtained are compared with its powder. The magnetic properties of free standing film of PANI is similar to its powder, and it varies with transition of insulator to metal after protonation. For elongated free standing film of PANI, on the other hand,both Pauli and Curie spin are higher than that of its powder and the free standing film this may be due to increasing of interaction between uncoupled electrons on quinoid ring at PANI chain.

Acta Physica Sinica. 1992 41(2): 347-352. Published 1992-01-05