Acta Physica Sinica

GENERALIZED FORMULA FOR SENSITIVITY OF REFLECTION SPECTRUM AND ITS APPLICATIONS

DAI SONG-TAO, ZHANG GUANG-YIN, ZHANG CUN-ZHOU — 1994-09-20

Author(s): DAI SONG-TAO, ZHANG GUANG-YIN, ZHANG CUN-ZHOU

We have deduced a formula for sensitivity of reflection spectrum from the general relation between dielectric constant and reflectivity. Using this unified formula, we have analyzed the sensitivity of reflection spectra of Lorentz oscillator and Drude free carrier, thus we have got a deeper understanding of the abnormal reflection-spectrum structures on the short-wave side of reststrahlen bands of some alkali-halide crystals and the feature of infrared reflection-spectrum of high-Tc superconductors.

Acta Physica Sinica. 1994 43(9): 1393-1403. Published 1994-09-20

RENORMALIZATION AND CRITICAL BEHAVIOR OF SINE-GORDON MODEL

DING GUO-HUI, XU BO-WEI, ZHANG YU-MEI — 1994-09-20

Author(s): DING GUO-HUI, XU BO-WEI, ZHANG YU-MEI

Using the Gaussian wave functional method, the ground state and the critical behavior of the continuum and discrte Sine-Gordon model are investigated, the results of the two different renormalization approach are compared.

Acta Physica Sinica. 1994 43(9): 1404-1412. Published 1994-09-20

OPACITY FUNCTION FOR ROTATIONALLY INELASTIC SCATTERING OF Ar+N2 SYSTEM IN IT'S LONG-RANGE POTENTIALS

REN TING-QI, LIU SHENG-DIAN, ZHANG QING-GANG, ZHANG YI-CI — 1994-09-20

Author(s): REN TING-QI, LIU SHENG-DIAN, ZHANG QING-GANG, ZHANG YI-CI

A new method is proposed to deal with the rotationally inelastic scattering of A+BC collision system. The matrix element 0,l/?)t|R′< is obtained analytically, the centrifugal potential takes the CS approximation, the rotationally term in the total Hamiltonian is treated by the Fourier transform and the time-dependent Schrodinger equation is approximated by the SOD method. Using this method the opacity function for Ar+N2 scattering system is calculated. The results show that the method introduced in the present paper is more suitable than the CCWP method in calculating the transition for long-range Ar+N2 potentials. And the calculational efficiency of our method is higher than the latter.

Acta Physica Sinica. 1994 43(9): 1413-1418. Published 1994-09-20

APPLICATIONS OF INVERSION SCATTERING THEORY TO e-H2O COLLISIONS

CHEN XUE-JUN, WANG YAN, LI BO, DENG XIN-YUAN — 1994-09-20

Author(s): CHEN XUE-JUN, WANG YAN, LI BO, DENG XIN-YUAN

The inversion scattering method was practically applied to e-H2O collisions. Based on the differential cross sections of e-H2O elastic scattering and using the inversion scattering mehtod, the spherical average potential of e-H2O interaction was derived. The obtained potential is complex and non-local. This potential can produce excellent results in agreement with experimental data.

Acta Physica Sinica. 1994 43(9): 1419-1426. Published 1994-09-20

INTERACTION POTENTIAL DRIVED BY INVERSION SCATTERING THEORY FOR EXTREMELY LOW-ENERGY e-He CO-LLISIONS

CHEN XUE-JUN, WANG YAN, CAO XIAO-PING — 1994-09-20

Author(s): CHEN XUE-JUN, WANG YAN, CAO XIAO-PING

Based on the experimental data of differential cross sections of e-He elastic collisions at 2 eV, the e-He interaction potential has been drived theoretically by the inversion scattering method. Using the obtained potential, the differential cross sections of e-He elastic collissions at 2,5eV were calculated theoretically. The results show that: 1)The e-He interaction potential at extremely low-enery is real and local one and has the characters of strong Van der Waals potential. 2) The WKB inversion is fail for the present case, but the quantum inversion is still successful. 3) The quantum inversion potential can produecd good reaults in agreement with experimental data.

Acta Physica Sinica. 1994 43(9): 1427-1432. Published 1994-09-20

THE kTH POWER SQUEEZING OF THE FIELD AMPLITUDE IN SQUEEZED NUMBER STATES

WU XING一LONG — 1994-09-20

Author(s): WU XING一LONG

We have studied the amplitude kth power squeezing in squeezed number states and derived the general formulas related to the squeezing effect. The squeezing propereies have been obtained for the cases of k=1,2,3 and 4 by means of numerical calculation, The results show that the AKPS has favourable applications in optical communication.

Acta Physica Sinica. 1994 43(9): 1433-1440. Published 1994-09-20

THE CONTROLLING PARAMETER IN A WIGGLER-PUMPED FREE-ELECTRON LASER WITH AN AXIAL-GUIDE MAGNETIC FIELD

GOU SAN-KUI — 1994-09-20

Author(s): GOU SAN-KUI

The basic equations are given for a wiggler-pumped free-electron laser with an axial-guide magnetic field. It is found that the evolution of the electron-field system is determined by a controlling parameter which contains the contributions of the electron beam, wiggler field, axial-guide magnetic field, and the initial state of the system. The collective instability is discussed and the threshold value of the controfling parameter is obtained. Farthermore, the radiation field is expressed in the cases of W＜WT and W＞WT.

Acta Physica Sinica. 1994 43(9): 1441-1446. Published 1994-09-20

INTERACTIONS BETWEEN ELECTRONS WITH WAVES IN THE FEL AND ITS GAIN ANALYSIS

ZHAO DONG-HUAN — 1994-09-20

Author(s): ZHAO DONG-HUAN

The interaction process between electrons with electromagnetic waves in the free electron laser (FEL) is analysed and the corresponding gain expression is-derived. The result shows that it not only reflects the coherent emittanee of FEL, but also expounds the property with output saturation of lasers. The result of analysis is close to the experiment condition of FEL.

Acta Physica Sinica. 1994 43(9): 1447-1454. Published 1994-09-20

THE EXTRAORDINARY TEMPERATURE CHARA-CTERISTICS OF TWO-BEAM COUPLING IN THE Ce: Eu: LiNbO3 CRYSTAL AND STRUCTURE PHASE TRANSFORMATION

1994-09-20

Author(s): LIU JIN-SONG, LIANG CHANG-HONG, AN YU-YING, LI MING-HUA, JIN CHAN, XU YU-HENG, WU ZHONG-KANG

In this paper, we report the extraordinary temperature phenomenon of two-beam coupling in the Ce: Eu: LiNbO3 crystal occuring at about 55, 70 and 110℃. The phenomenon was related to the phase transformation of the crystal structure at these temperatures. An internal electric field is induced by the phase transformation. Then, the structure of space electric charge field is varied, thereby the two-beam coupling is influenced. The formula of phase transformation electrical field (PTEF) changing with temperature is obtained by means of phenomenological method. The theoretical curve in accord with experimental one was given by using the formla and the one-carrier and one-level band-conduction model, which is in accordaace with the experimental curve. The order of the PTEF, 10５Ｖ·ｍ-1，was calculated, which is the value between the order of diffusion electric field and maximum space electric charge field and is the same as the one reported iv Ref. [7].

Acta Physica Sinica. 1994 43(9): 1455-1459. Published 1994-09-20

MEASUREMENT OF THERMALLY INDUCED NONLINEARITY BY TWO MODIFIED Z-SCAN METHODS

TIAN JIAN-GUO, ZANG WEI-PING, ZHANG GUANG-YIN — 1994-09-20

Author(s): TIAN JIAN-GUO, ZANG WEI-PING, ZHANG GUANG-YIN

In this paper we suggest two modified Z-scan methods with enhanced sensitivity compared with common Z-scan method. By using these methods we measure thermally induced nonlinearity of liquid. The experimental results agree essentially with the theories.

Acta Physica Sinica. 1994 43(9): 1460-1465. Published 1994-09-20

THE PROPERTIES OF THE MHD OSCILLATIONS IN TEXTOR TOKAMAK PLASMAS

KUANG GUANG-LI, G.WAIDMANN — 1994-09-20

Author(s): KUANG GUANG-LI, G.WAIDMANN

The properties of the N41-1D oscillations (Mirnov Oscillations) in ohmic TEXTOR tokamak plasmas are systematically described in this paper based on experimental data, including mainly the principal modes of the MHD oscillations and the correlaion among the oscillations, the propagating direction of the MHD oscillations, as well as the correlative properties among the oscillative temperature, density and density fluctuation of the m=2/n=1 mode.

Acta Physica Sinica. 1994 43(9): 1466-1475. Published 1994-09-20

A THEORY OF MW-LATITUDE IONOSPHERIC IRREGULARITIES PRODUCED BY ATMO-SPHERIC GRAVITY WAVES

HUANG CHAO-SONG, LI JUN, M .C. KELLEY — 1994-09-20

Author(s): HUANG CHAO-SONG, LI JUN, M .C. KELLEY

Basic properties of large scale irregularities in the rnid-latitude ionospheric F region and their relationship with atmospheric gravity waves are studied. The temporal evolution of the plasma Perkins instability is analyzed. It is found that the instability saturates at a small amplitude. The coupling between the Perkins instability and gravity waves is discussed and it is shown that gravity waves can initiate the plasma instability in the mid-latitude F region. The plasma instability initiated by gravity waves can evolve into steady-state perturbations, large amplitude wave-like structures, and spatially and temporally modulated irregularities. The theory indicates the production mechanism of the large scale irregularities in the mid-latitude ionosphere.

Acta Physica Sinica. 1994 43(9): 1476-1485. Published 1994-09-20

IMPROVED CONFINEMENT PHASE IN RAMPING UP PLASMA CURRENT BY TOROIDAL FIELD

1994-09-20

Author(s): MENG YUE-DONG, GAO XIANG, FAN SHU-PING, LI JIAN-GANG, LUO JIA-RONG, TONG XING-DE, ZHANG WEI, HAN YU-QIN, GONG XIAN-ZU, JIANG JIA-GUANG, YIN FU-XIAN, ZENG LEI, LING BI-LI, YIN FEI, DING LIAN-CHENG, ZHA

Using a small pulse of toroidal vortex eletric field (4.4V/m, 0.45ms), plasma current is successfully ramped up from the plateau (55kA) to the second plateau (60kA) with a ramp rate dIp/dt<12MA/s on a time scale much fast than the classical skin time in the HT-6M Tokamak. The phenomena of improved confinement is observed in the present experiment. Particle confinement time is enhanced 2.1 times and energy confinement time, meanwhile, is enhanced 1.6 tines after ramping current up.

Acta Physica Sinica. 1994 43(9): 1486-1494. Published 1994-09-20

A STUDY OF THE PHYSICOCHEMICAL CHARACTER OF THE INTERACTION OF THE LIPOSOME CONTAINING OLEIC ACID OF THE LIQUID-CRYSTAL STATE AND BIOMEMBRANE

ZHANG JING, SUN RUN-GUANG — 1994-09-20

Author(s): ZHANG JING, SUN RUN-GUANG

The structure of the liquid crystal state of the new antiturner agent, polyphase liposome containing oleic acid, has been studied by small angle puiypnase scattering (SAXS) and 31P nuclear magnetism resomance (31P-NMR). Experimental results show that the presence of cholesterol, oleic acid, nonionic surfactant will highly affect the structure of the liquid crystal state of the PE liposome containing oleic acid. The liquid crystal state of liposome with oleic acid made from phosphoric buffer solution containing polyvinylpyrrolidone consists of both lamellar-hexagonal phase and lamellar-cubic phase. Electron-spin-resonance (ESR) experiment shows that the W/S value in the Ehrlich ascites tumor cell increases as the amount of liposome increases.

Acta Physica Sinica. 1994 43(9): 1495-1501. Published 1994-09-20

ENERGY SPECTRA AND LOCALIZED ELECTRON STATES OF SOLITON LATTICE IN Na-DOPED TRANS (CH)x

AN ZHONG, LI ZHAN-JIE, YAO KAI-LUN — 1994-09-20

Author(s): AN ZHONG, LI ZHAN-JIE, YAO KAI-LUN

Starting from the extensional discrete model SSH Hamiltonian containing an external Coulomb potential arising from interchain charged solitons and the counterions, the intrachain electron-electron interaction, the energy spectra and electron states of soliton lattice have been studied in trans-polyacetylene. The results show that: two bound states have been found at the bottom of valence band and several other states at the top of conduction band. With the increasing of the dopant concentration, the localization of bound states are weakened and the discrete soliton energy levels in the forbidden band move into the soliton band. When the dopant concentration is up to 16.67%，all the discrete electron states of soliton lattice disappear and become extended ones. It is found that the forbidden band width increases and the gap (between the top of the soliton band and the bottom of conduction band) namows with the doping level increasing. Furthermore, the gap (from the bottom of the soliton band to the top of valence band) has a maximum at the critical doping level. Finally, the effect of e-e interaction on the energy spectra of soliton lattice is discussed.

Acta Physica Sinica. 1994 43(9): 1502-1506. Published 1994-09-20

A NEW METHOD OF CALCULATING ATOMIC RADIUS AND WORK FUNCTION OF METALS

YANG DE-QING — 1994-09-20

Author(s): YANG DE-QING

In this paper, a new quasi-atomic model of metal, new concepts of effective valence electron number and equaivalent orbital radius of atom are put forward. Problems related to metal are studied and analysed by using the model and the concepts. Characteristic parameters concerned with metal can be effectively calculated with under standing the electron distribution of metallic atom, namely the principal quantum number and total number of valence electron of atom. Parameters which can be calculated are effective nuclear charge number of atom, density of free electron, atomic radius, Fermi energy and work function of the metal concerned. Atomic radius and work function of 68 metals and density of free electron of 17 metals are calculated and compared with experimental values, results show that the former two are both quite in accordance with the experimental results and the latter one is better than the results calculated by free-electron model. Thus it can be seen that the model and methods are in conformity with the actual situation of metals, and its applications are proved to be reliable.

Acta Physica Sinica. 1994 43(9): 1507-1516. Published 1994-09-20

STUDIES OF FLUX CREEP IN Y0.9Eu0.1Ba2Cu3O7-δ

1994-09-20

Author(s): CAI MENG, FANG MING-HU, ZHANG XUAN-JIA, JIAO ZHENG-KUAN, ZHANG QI-RUI, RONG XI-SHEN, ZHAO BAI-RU

The magnetic hysteresis and relaxation behaviors in ＹＢａ2Ｃｕ3Ｏ7-δ and Ｙ0.9Ｅｕ0.1Ｂａ2Ｃｕ3Ｏ7-δ samples were measured in the wide ranges of temperature (4.2-80K) and field (0-8 T). The M(t), Jc(T) and Ueff(J) relationships in these samples were studied and several theoretical models were tested. The results show:(1)Both the effective pinning energy and critical current density in the absence of flux creep are obviously higher in Ｙ0.9Ｅｕ0.1Ｂａ2Ｃｕ3Ｏ7-δ than in ＹＢａ2Ｃｕ3Ｏ7-δ sample, which indicates the introductions of new pinning centers with larger pinning energy by the partial substitution of Eu for Y. (2) Compared with other models, the collective flux creep theory gives the best description on our experimental results and thus this work provides a new experimental evidence for this theory.

Acta Physica Sinica. 1994 43(9): 1517-1522. Published 1994-09-20

NEW SYMMETRY THEORY OF THE HIGH-Tc SUPERCO-NDUCTIVITY FOR ELECTRON-PHONON SYSTEMS

YI LIN — 1994-09-20

Author(s): YI LIN

By means of a new Cooper pair mean field approximation, an effective phonon-Cooper pair interaction is derived for electron-phonon systems. It is demonstrated that through exchange of virtual Cooper pairs, phonons with opposite wave vectors can feel an effective attractive force and bound into phonon pairs, which leads to a new superconducting phonon state. It is found that the electron Cooper state and the superconducting phonon state consist of the stable and symmetric superconducting ground state with high critical temperature. In the weak coupling limit of phonon-Cooper pair interactions, the ground state symmetry breaks down and becomes the traditional BCS state.

Acta Physica Sinica. 1994 43(9): 1523-1530. Published 1994-09-20

NEW FERMI-SUPERCONDUCTING STATE FOR ELECTRON-PHONON SYSTEMS

YI LIN — 1994-09-20

Author(s): YI LIN

Based on an extended effective electron-phonon model, considering the strong correlation interaction between electrons, the Bogoluibov approximation of electron operators is presented and an effective phonon-electron interaction is derived. It is shown that through exchange of virtual electrons, longitudinal phonons with oppo-site wave vectors can feel an effective attractive force and form phonon pairs with an electron. For an approprate phonon density, a new superconducting phonon state with the high critical temperature appears.

Acta Physica Sinica. 1994 43(9): 1531-1536. Published 1994-09-20

SPLITTING OF LO, TO MODE RAMAN SPCETRA OF SINGLE CRYSTAL KTiOPO4

1994-09-20

Author(s): LIANG WEI, JIANG SHAO-LIN, HUA BAO-YING, JIANG YI-JIAN, CHEN GANG, ZHANG KE-CONG, WEI MING

The vibration spectra of single crystal KTiOPO4 was analysed using group method tnd measured in the frequency shift range of 50-1600cm-1 at room temperature. The Raman peaks of all LO, TO modes were obtained. Upon the result of LO-TO splitting, the effective charge, mode strength and static dielectric constant of polar modes of KTP single crystal were calculated.

Acta Physica Sinica. 1994 43(9): 1537-1543. Published 1994-09-20

WAVEFUNCTION MIXTURE AND COMPOSITION FOR HYBRIDIZED ZEEMAN STATES OF P IN Si

SHEN XUE-CHU, ZHU JING-BING, MU YAO-MING, LIU PU-LIN — 1994-09-20

Author(s): SHEN XUE-CHU, ZHU JING-BING, MU YAO-MING, LIU PU-LIN

We report direct experimental determination of the wavefunction mixture and composition for hybridized Zeeman states of P in Si. The intensity evolution of the Zeeman transitions nearby anti-crossing region for the isolated P donors in high pure Si bas been measured quantitatively by use of high sensitive and high resolution photothermal ionization spectroscopy (PTIS); The wavefunction compositions and their evolutions upon magnetic field for the hybridized Zeeman states of bounded electrons of impurities have been deduced from the measurement. A variational calculation under the frame of effective mass approach has been performed to estimate theoretically the wavefunction composition. The results are campare with experimental ones.

Acta Physica Sinica. 1994 43(9): 1544-1552. Published 1994-09-20

NEW PHOTOEMISSIVE THIN FILM FOR ULTRASHORT DURATION LASER PULSE DETECTION

WU JIN-LEI, LIU WEI-MIN, DONG YIN-WU, WU QUAN-DE — 1994-09-20

Author(s): WU JIN-LEI, LIU WEI-MIN, DONG YIN-WU, WU QUAN-DE

A kind of photoemissive thin films which can be exposed to or stored in the atmosphere and can be used again in a vacuum system without any activation process for laser pulse detection is presented. They are different from usual photoemissive materials, since they do not contain alkali elements. They consist of metallic oxide thin film or other material thin film embedded with metallic ultrafine particles. A main interesting material is barium oxide thin film embedded with Ag ultrafine particles. The phenomenon that photoemissive sensitivity of this kind of ultrafine particle thin film rose up under the action of laser pulses was discovered.

Acta Physica Sinica. 1994 43(9): 1553-1558. Published 1994-09-20

FRACTURE STRENGTH STUDIES OF POLYCRYSTALLINE DIAMOND FILMS PRODUCED BY DC PLASMA CVD

LIAO KE-JUN, WANG WAN-LU — 1994-09-20

Author(s): LIAO KE-JUN, WANG WAN-LU

The fracture strength of Polycrystalline diamond films produced by DC plasma CVD is investigated. The fracture strength of circular diamond film was measuned by a burst pressune technique. Experimental results have shown that the fracture strength is considerably dependent on grain size, sample thickness, apertune radius, methane concentration and substrate temperature. The results have also been discussed.

Acta Physica Sinica. 1994 43(9): 1559-1563. Published 1994-09-20

A STUDY OF THE NONLINEAR POLARIZATION CONDITIONS OF SILICA

BAI YING-XIN, ZHANG ZHU-HONG, FAN DIAN-YUAN, WANG ZHI-JIANG, ZHANG GUO-QING — 1994-09-20

Author(s): BAI YING-XIN, ZHANG ZHU-HONG, FAN DIAN-YUAN, WANG ZHI-JIANG, ZHANG GUO-QING

It is experimentally shown that temperature and static electrical field (or direct current field) play important roles in the nonlinear polarization of silica and there is a temperature threshold. For an optical fiber, the nonlinear polarization depends on the average power density in the preparing optical fiber and there is an average power density threshold. Finally, some theoretical analyses are made about them.

Acta Physica Sinica. 1994 43(9): 1564-1567. Published 1994-09-20