Acta Physica Sinica -

MAGNETIC COUPLING BETWEEN THE RESONANT JOSEPHSON TUNNEL JUNCTION AND THE APLLIED MICROWAVE (Ⅰ)

CUI GUANG-JI, MENG XIAO-FAN, SHAO KAI — 1982-06-05

Author(s): CUI GUANG-JI, MENG XIAO-FAN, SHAO KAI

The resonant Josephson tunnel junction is used generally in the Josephson voltage-standard works. This paper starting from the forced vibration model, taking account of the magnetic coupling boundary condition, treats a junction in the waveguide system, and result which agrees with those of the experiments is obtained. In the experiment we improved the short circuit unit of the waveguide, system, thus the microwave leakage was reduced and the short circuit condition has been improved. The result of our experiment at low temperature shows that the improving is effective.

Acta Physica Sinica. 1982 31(12): 1-7. Published 1982-06-05

MAGNETIC COUPLING BETWEEN THE RESONANT JOSEPHSON TUNNEL JUNCTION AND THE APLLIED MICROWAVE (Ⅱ)

CUI GUANG-JI, MENG XIAO-FAN, SHAO KAI — 1982-06-05

Author(s): CUI GUANG-JI, MENG XIAO-FAN, SHAO KAI

This paper reports a series of controlled experiments carried out on the micro-stripline. The result of the experiments showed, when the resonant Josephson tunnel junction was placed there, where the magnetic field on the stripline was stronger, the coupling would be better. Thus the point of view of the magnetic coupling is further comfirmed.

Acta Physica Sinica. 1982 31(12): 8-12. Published 1982-06-05

THEORETICAL ANALYSIS OF THE TWO-MAGNON RAMAN SPECTRA OF RbNiF3

ZHENG HANG — 1982-06-05

Author(s): ZHENG HANG

Two-magnon Raman spectra of RbNiF3 are calculated for the temperature range between 0 K to Néel point TN(= 133 K). From considerations of the general symmetry principle and the experimental results, we have derived the Hamiltonian of interaction between the magnetic system and the radiation field. The method of the equation of motion of retarded Green's function is used to obtain the analytic expression of the two-magnon Raman scattering intensity. In the two-magnon propagator, both the effects of energy renormalization and the life time have been taken into account. Finally, quantitative calculations are performed with proper approximations using computer. Although there are no adjustable parameters, the results account very well for the observed temperature dependence of both the. peak position and the line width in the range from 0 K up to TN.

Acta Physica Sinica. 1982 31(12): 13-27. Published 1982-06-05

THE 2D ABSORTION SPECTRUM OF Al I: A MQDT ANALYSIS

ZHAO JUN — 1982-06-05

Author(s): ZHAO JUN

The Multichannel Quantum Defect Theory (MQDT) has been applied to the analysis of the 2D absorption spectrum of atomic aluminium. The model consists of the mixing of three dissociation channels with different ionization thresholds. By suitably taking the values of the eigen-parameters μα,Dα which depend on electron energy and on the transformation matrix elements Uiα, the 2D autoionization spectrum between the first and second ionization limits is calculated and the result is compared with Roig's measurements. Extending the se parameters to the region of discrete spectrum, we obtained the Rydberg series of 2D energy levels as well as their oscillator strengths which also coincide with the analyses of Lin and Weiss and related experiments.

Acta Physica Sinica. 1982 31(12): 28-36. Published 1982-06-05

DYNAMIC ABERRATION CORRECTION IN A COMBINED SCANNING ELECTRON BEAM SYSTEM

XIMEN JI-YE, LI YU — 1982-06-05

Author(s): XIMEN JI-YE, LI YU

Based on the results of the previous paper [1], the dynamic aberration correetion in a combined scanning electron beam system is studied. The possibility of dynamic aberration correction by using electro-magnetic multipole fields is discussed. The formulas for calculating aberrations, caused by round and multipole correctors, are derived.Thus we show that in a combined scanning electron beam system most of the third order deflection aberrations may be eliminated by properly using a dynamic aberration correction system, consisting of round lens, deflector and quadrupole devices.

Acta Physica Sinica. 1982 31(12): 37-43. Published 1982-06-05

STUDYING THE LAWS OF DEPENDENCE OF REFRACTIVE INDICES OF AMORPHOUS As2S3 ON HYDROSTATIC PRESSURE USING HIGH-PRESSURE MICROSPECTROSCOPIC SYSTEM

GUO CHANG-XIN, ZHA CHANG-SHENG — 1982-06-05

Author(s): GUO CHANG-XIN, ZHA CHANG-SHENG

The pressure and wavelength dependence of refractive indices of amorphous As2S3 have been studied by means of observing transmission light interference spectrum under room temperature with the high-pressure microspectroscopic system in conjunction with the gasketed diamond anvil cell, in which methanol-ethanol mixture was used as pressure liquid with hydrostatic pressure up to 66kbar and wavelength between 400-900 nm. The pressure was monitored by ruby R-line shift. Amorphous As2S3 thin film samples a few micrometers in thickness were prepared by vacuum evaporation. Under our experimental conditions, neither the light of 441.6 nm He-Cd laser used for excitation of the ruby gauge, nor that of the Br-W lamp for measurement of light transmission, showed any detectable influence on the optical properties of the sample.By observing the interference maxima at energies below the absorption threshold and using the results of. Gerlich et al. of the pressure dependence of volume of a-As2S3, the pressure dependence of refractive index between 500-850 nm have been determined. The refractive index of amorphous As2S3 is significantly pressure-sensitive, increasing by 35% at 650 nm with pressure change of 66 kbar. Analysis of experimental data by least-square method on the computer gives the coefficients of the nonlinear formula n(p)=n(0)+Ap+Bp2, where n(p) and n(0) are refractive indices at pressure p and 1 bar, respectivelly; coefficients A and B are relative to wavelength, for example {A=9.62×10-3 kbar-1,B=2.07×10-3 kbar-2, for wavelength) λ = 800nm and other values were given in the paper. This relationship is different from the results of Weinstein et al. and Galkiewicz et al., where linear relationship between n and p at fixed wavelength in infra-red regime was reported. The difference, however, may be attributed to the different method of sample preparation etc.

Acta Physica Sinica. 1982 31(12): 44-54. Published 1982-06-05

La-Ga BINARY SYSTEM PHASE DIAGRAM

LU XUE-SHAN, XIE SI-SHEN, LIANG JING-KUI — 1982-06-05

Author(s): LU XUE-SHAN, XIE SI-SHEN, LIANG JING-KUI

The Ga-rich side of La-Ga binary system phase diagram has been investigated by means of X-ray diffraction and differential thermal analysis.In this portion of the phase diagram there is a peritectic reaction. A new interme-tallic compound LaGa6 is found, its homogeneous range is extremly narrow and it is formed peritectically at 700℃. It belongs to the tetragonal system with space group D4h3 -P4/nbm. Bach unit cell contains two formula units LaGa6. Its lattice parameters are: α =6.1041?, c =7.7052?.In addition, it is established that the in termatallic compound LaGa2 has a homogeneous range from 66.7 A/0 to 71.6 A/0 Ga. In this region, with the addition of gallium, the lattice parameters a increses, but c reduces. The result shows that this solid solution is formed due to one lanthanum atom substituted randomly by a pair of gallium atoms in x-y plane.

Acta Physica Sinica. 1982 31(12): 55-61. Published 1982-06-05

THE INFLUENCE OF THICKNESS, APPLIED ELECTRIC FIELD AND MEDIUM TEMPERATURE ANNEALING ON THE ACTIVATION ENERGIES FOR CONDUCTIVITY OF a-Si:H

YAN CHENG — 1982-06-05

Author(s): YAN CHENG

Measuring the temperature dependence of conductivity of a series doped samples of different thickness, we find three activation energies in the range of 300-500 K. After prolonged annealing in 180-250℃, the positions of two kinks formed by these activation energies shift to high temperature side. In thinner samples the shifting rate is larger than that in thicker samples. In a very thin sample the positions of the kinks even shift spontaneously after being kept at room temperature for a long-period.Changing the voltage, drop across the sample during measuring significantly influences the values of high and medium temperature activation energies. In thicker samples this kind of influence is stronger than that in thinner ones.Most of these results are interpreted by a tentative model which has been checked by computer graphics rather successfully.

Acta Physica Sinica. 1982 31(12): 62-74. Published 1982-06-05

DIFFRACTION INTEGRAL FORMULA FOR MISALIGNED OPTICAL SYSTEMS

HONG XI-CHUN, HUANG WEI-GANG, WANG SHAO-MIN — 1982-06-05

Author(s): HONG XI-CHUN, HUANG WEI-GANG, WANG SHAO-MIN

On the basis of Collins' diffraction in tegral theory, a diffraction integral formula for misaligned optical systems has been devived employing a kernel expressed in terms of augmented 4×4 transfer matrix elements.

Acta Physica Sinica. 1982 31(12): 75-83. Published 1982-06-05

DIRECT MEASUREMENT OF RECOVERY TIME OF BDN DYE WITH THE PULSE TRAIN FROM MODE-LOCKED LASER

HUO CHONG-RU, LAI RUI-SHENG, ZHU ZHEN-HE, DING ZHI-GAO — 1982-06-05

Author(s): HUO CHONG-RU, LAI RUI-SHENG, ZHU ZHEN-HE, DING ZHI-GAO

Ground state recovery time of organic dye BDN in the solvents dichlorethane and lodoethane was measured by means of the pump-probe technique. In this experiment, the integrated transmisson of a whole pulse train was measured as a function of time delay between pumping and probing pulses. The pulse train used in the experiment is generated by a passively mode-locked Nd : YAG laser. The results obtained agree with solutions of the rate equations for the three level model of bleachable dye.

Acta Physica Sinica. 1982 31(12): 84-89. Published 1982-06-05

THE EFFECTS OF STOCHASTIC MAGNETIC FIELD ON THE WAVE-DRIVEN CURRENT

XIA MENG-FEN, QIU YUN-QING — 1982-06-05

Author(s): XIA MENG-FEN, QIU YUN-QING

The effects of stochastic magnetic field on the wave-driven current are studied. It is shown that in the central region of the plasma the current density and the dissi-pative power density of the waves will decrease, and the efficiency will increase. In the gradient region (outer region), however, the current density and the power density will increase, and the efficiency will decrease. These effects may be important for the tokamaks driven by the waves with high phase velocity and wide resonance width.

Acta Physica Sinica. 1982 31(12): 90-95. Published 1982-06-05

TRACE ANOMALY AND THE TIME SYMMETRIC BOUNCING COSMOLOGICAL MODEL

LIU LIAO, LI JIAN-ZHEN — 1982-06-05

Author(s): LIU LIAO, LI JIAN-ZHEN

For conformal flat space-time of k = 0, we calculate the one-loop contribution to the effective action from the conformal trace anomaly and obtain a time symmetric bouncing cosmological solution, which avoids the cosmological singularity.

Acta Physica Sinica. 1982 31(12): 96-99. Published 1982-06-05

M?SSBAUER SPECTROSCOPY FOR Bi-YIG MONOCRYSTALS

LING QI-FEN, XU XIAO-ZHEN, LIU CHAO-XIN — 1982-06-05

Author(s): LING QI-FEN, XU XIAO-ZHEN, LIU CHAO-XIN

M?ssbauer spectroscopy for Y3-xBixFe5O12 monocrystals have been studied and a preliminary consideration on increase of the Curie temperature of the materials along with its bismuth content x is presented.

Acta Physica Sinica. 1982 31(12): 100-103. Published 1982-06-05

DRIFT MOBILITIES OF CARRIERS IN AMORPHOUS FILMS OF PVCz-TNF CHARGE-TRANSFER COMPLEXES

YANG DA-LIN, WAN MEI-XIANG, ZHANG JING-WEN, QIAN REN-YUAN — 1982-06-05

Author(s): YANG DA-LIN, WAN MEI-XIANG, ZHANG JING-WEN, QIAN REN-YUAN

The drift mobilities of carriers in amorphous charge-transfer complexes of PVCz-TNF were obtained by Time-of-Flight. Differences in the transport characteristics between electrons and holes were observed. The transient current trace of electrons has a knee by which the transit time can be determined, but. the current trace of holes is featureless indicating that tT is dispersive. The transient current of holes can be analysed by Scher-Montroll theory. At low electrical field μh is independent of the field. Combining the results of dark conductivity measurements, we conclude that the non-ohmic conductivity at high field is contributed by the field-dependent mobilities and carrier concentrations that are both increasing with the field strength.

Acta Physica Sinica. 1982 31(12): 104-109. Published 1982-06-05

THE ROLE OF SPECIAL REFLEXIONS IN A SET OF STARTING PHASES

GU YUAN-XIN — 1982-06-05

Author(s): GU YUAN-XIN

Phase development in the MULTAN procedure is based on the permutation of the starting phase set. When a new phase of a gereral reflection is derived from the combination of two special reflections of the starting set, it may result in large error. If this occurs in the early stage of the phase development, the error is difficult to be eliminated afterwards. The wrong phase should then strongly affect the process of the phase development and leads sometimes to the failure of the structure determination. One way of dealing with this problem is to check the convergence mapping carefully and change some of the reflections in the starting set. Tests have been made on modifying a starting set that led to the MULTAN failure. It turns out that just a slight but proper modification of the starting set can greatly improve the process of phase development and leads to the correct solution of the structure.

Acta Physica Sinica. 1982 31(12): 110-115. Published 1982-06-05

THE CRYSTAL STRUCTURE OF P-CHLORO BENZOYL PIPERIDINE

SONG SHI-YING, ZHENG QI-TAI, HE CUN-HENG — 1982-06-05

Author(s): SONG SHI-YING, ZHENG QI-TAI, HE CUN-HENG

The p-chloro benzoyl piperidine. C12H14 ONCL crystal belongs to the orthorhombic system. The space group is P21 21 21 with α=11.490(6)?, b = 10.462(5)?, c=9.928(5)?, z = 4 and calculated density Dc= 1.2410 gcm-3. The intensity data were collected on a Philips PW-1100 diffractometer. With the chlorineatom position found from Patterson method, the structure was determined by Fourier synthesis and refined by full-matrix least square method to a final R value of 0.093 for 697 reflexions. The hydrogen atom coordinate parameters were obtained from difference Fourier synthesis. The absolute configuration of molecule was determined by anomalous scattering method.

Acta Physica Sinica. 1982 31(12): 116-120. Published 1982-06-05