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Volume 4 Issue 7
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Original Articles
A MECHANISM FOR PULSAR DRIFT
Asghar Qadir
Chin. Phys. Lett. 1987, 4 (7): 289-292 .  
Abstract   PDF(pc) (40KB) ( 398 )
An electromagnetic mechanism for pulsar drift is suggested, which is to consider the collapsed core as Kerr-Newmann sources with strong magnetic field of the nascent pulsar. The magnetic field would drive both positive and negative charges to move along a helix but in opposite directions. The net effect will be to add angular momentum along the axis of rotating sources, which produces an asymmetric force to cause the pulsar drift.
THE STUDY ON GETTERING MECHANISM OF DOUBLE-GETTERING TECHNIQUE
MA Zhenhong*, DAI Daoyang*, ZHOU Shiren, YE Yizheng, YE Shuichi
Chin. Phys. Lett. 1987, 4 (7): 293-296 .  
Abstract   PDF(pc) (43KB) ( 339 )
The applications of double-gettering technique (DGT) for silicon single crystal indicate its strong gettering effectiveness. By using E-center model, the minimum concentration of phosphorus, gettering process and the continuous gettering ability were investigated. It was pointed out that the gettering functions of phosphorus and dislocation loops result in extremely strong gettering effectiveness of DGT.
SOME ELECTRONIC FACTORS INFLUENCING SUPERCONDUCTIVITY IN SOME RARE-EARTHLIKE ELEMENTS AND THE BEGINNING OF THE RARE-EARTH SERIES
ZHANG Liyuan
Chin. Phys. Lett. 1987, 4 (7): 297-300 .  
Abstract   PDF(pc) (43KB) ( 394 )
There exist general trends which are favorable to superconductivity in the electronic structures of the rare-earth-like elements and the beginning of the rare-earth series. The principal factors are the f partial wave components in their electronic structures and the strongly induced high η mainly due to the d-f scattering. Applying pressure or some equivalent effect by alloying can be used to increase Tc.
LOWER HYBRID CURRENT DRIVE EXPERIMENTS IN THE HT-6M TOKAMAK
JIANG Tongwen, LIU Yuexiu, GUO Wenkang ZHANG Xuelei, LUO Jiarong
Chin. Phys. Lett. 1987, 4 (7): 301-304 .  
Abstract   PDF(pc) (53KB) ( 417 )
Lower hybrid current drive (LHCD) experiments with a multijunction grill have been performed in the HT-6M tokamak. When the RF power pulse with 15ms risetime is injected into the plasma. the toroidal current amplitude is raised, but the temporal variation of the loop voltage does not have measurable change. The efficiency of current drive is Irf/ Prf=0.57kA/kW at ne =3x1012cm-3 and Bt=8KG. It seems that the multijunction grill has the same efficiency as the ordinary grill on the LHCD experiments.
TUNNELING EFFECT IN HEAVY-FERMION SUPERCONDUCTORS
XU Jihai
Chin. Phys. Lett. 1987, 4 (7): 305-308 .  
Abstract   PDF(pc) (47KB) ( 331 )
The tunneling effects between normal metal and heavy-fermion superconductor(HFS), between HFS and BCS superconductor, and between two identical HFSs are theoretically studied by using the two-gap model. The results exhibit many deviations from BCS single-gap theory.
CORRELATIONS OF LATTICE VIBRATIONS
FU Ying
Chin. Phys. Lett. 1987, 4 (7): 309-312 .  
Abstract   PDF(pc) (43KB) ( 376 )
A simple new way is developed to analyze the correlations of lattice vibrations based on the.fundamenta1 recursion method. The applications are significant to the cases of perfect crystalline silicon and the crystals of silicon with dilute impurities, such as substitutional boron and interstitial lithium.
THE ISOTHERMAL DISCHARGE OF POLYDICHLORO-P-XYLYLENE ELECTRETS
XU Fudong, OUYAMG Yi
Chin. Phys. Lett. 1987, 4 (7): 313-316 .  
Abstract   PDF(pc) (44KB) ( 362 )
A formula for isothermal decay of the surface potential of polydichloro-p-xylylene (PDCPX) electrets has been obtained experimentally. A model has been put forward to describe the discharge process in the electrets, and the experimental formula could also be derived from the model.
SOME NEW SOLUTIONS DERIVED FROM THE 5-DIMENSIONAL THEORY
LU Huiqing*, FENG Chengtian
Chin. Phys. Lett. 1987, 4 (7): 317-320 .  
Abstract   PDF(pc) (38KB) ( 408 )
The applications of the 5-dimensional coordinate transformations in the 5-dimensional theory lead us to some new solutions for the 4-dimensional Einstein-Maxwell equations and the relevant scalar equation. From the Kerr solution we derive the corresponding solution. And we propose a new method to solve the usual 4-dimensional Einstein-Maxwell equations, illustrating by an example.
INITIAL STATE EFFECT OF CORE-LEVEL NORMAL PHOTOELECTRON DIFFRACTION
TANG Jingchang
Chin. Phys. Lett. 1987, 4 (7): 321-324 .  
Abstract   PDF(pc) (56KB) ( 350 )
The photoelectron modulation functions of system C(2x2)S-Ni(001),1s ( E ) and 2p(E), which correspond to 1s and 2p initial states respectively, have been calculated., It is shown that 1s (E) and 2p(E) are out of phase. This initial state effect of core-level normal photoelectron diffraction (NPD) has been proved in multiple-scattering scheme and confirmed by a comparison between theoretical and experi-mental results.

PEAK ASYMMETRY OF AC STARK SPLITTING IN RESONANT EXCITATION OF MULTILEVEL SYSTEMS DUE TO THE EXISTENCE OF NEAR-DEGENERATE STATES
HOU Meiying, ZHANG Jian, ZHU Qingshi*
Chin. Phys. Lett. 1987, 4 (7): 325-328 .  
Abstract   PDF(pc) (50KB) ( 394 )
Calculation on resonant excitation of a four-level system with a pair of near-degenerate intermediate states is presented. It is shown that due to the presence of these near-degenerate states, reversed peak asymmetry and asymmetric absorption(ionization) profile is obtained.
WEAK LOCALIZATION, TIME REVERSAL SYMMETRY AND PHONON INTERFERENCES
CAI Jianghua(Chien-Hua Tsai)
Chin. Phys. Lett. 1987, 4 (7): 329-332 .  
Abstract   PDF(pc) (31KB) ( 426 )
Being a direct result of the wave nature of elementary excitations, the full effect of weak localization is certainly not limited to electrons uniquely. In order to display the phenomenon, the key is in each case to find a time-reversal symmetry-breaking mechanism. A possible way to realize the full effect of weak localization in the case of phonons is here proposed.
THE EXPLORATION OF HABIT CHANGE OF 57Fe3+ : KDP BASED ON MöSSBAUER STUDIES
WANG Wenshan CHAO Yigun, ZHANG Yuchang, WANG Zhiying
Chin. Phys. Lett. 1987, 4 (7): 333-335 .  
Abstract   PDF(pc) (38KB) ( 449 )
The Mössbauer study on mechanism of habit change has been made on KH2PO4(KDP) crystals grown in the presence of 57Fe3+ iron impurities. Mössbauer spectra of the 57Fe3+: KDP exhibit a typical quadrupole split Fe3+ pattern at room temperature. The quadrupole splitting ΔE(Q)=0.5lmm/s, and the isomer shift IS=0.40mm/s are obtained from computer fitting. Based on experimental results and theoretical calculation, the Fe3+ can occupy the interstitial positions in the lattice.
12 articles