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Volume 2 Issue 7
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Original Articles
COMPUTER SIMULATION OF THE CONDENSATION PROCESS ON TOP OF A GROWING WHISKER
WANG Jing-han, LI De-xiou
Chin. Phys. Lett. 1985, 2 (7): 289-292 .  
Abstract   PDF(pc) (39KB) ( 418 )
The condensation process of a growing whisker is simulated by a computer. Two whisker models which have fcc and hcp structure respectively are obtained and some details of formation about the hcp structure are discussed.

SYMBOLIC DESCRIPTION OF PERIODIC WINDOWS IN THE ANTISYMMETRIC CUBIC MAP
ZENG Wan-zhen, DING Ming-zhou, LI Jia-nan
Chin. Phys. Lett. 1985, 2 (7): 293-296 .  
Abstract   PDF(pc) (36KB) ( 410 )
A sequence of three-letter words was constructed for the antisymmetric map Xn+1 = F(Xn, A) = A*Xn+ ( 1 - A ) *Xn, Which contains all the information about the occurrence of periodic windows on the parameter axis.

ABSORPTION AND EMISSION SPECTRA OF RARE-GASES IN VACUUM ULTRAVIOLET REGION
YANG Li-sheng, GE Ji*
Chin. Phys. Lett. 1985, 2 (7): 297-300 .  
Abstract   PDF(pc) (93KB) ( 384 )
The vacuum ultraviolet absorption and emission spectra of rare-gas vander Waals molecules were observed. A large broadening of at least 240Å of Xe first resonance absorption line was obtained at cell presgure 4 atm. Strong continuous emission of heavier rare gases at 1300-3000Å was obtained using self-triggered condensed discharge in a π-shaped quartz discharge tube.
THE EFFECT OF HEAT TREATMENT ON HARD MAGNETIC PROPERTIES OF AMORPHOUS Fe78Nd16B6 ALLOY
SHEN Bao-gen, ZHAO Jian-gao, ZHAN Wen-shan
Chin. Phys. Lett. 1985, 2 (7): 301-304 .  
Abstract   PDF(pc) (56KB) ( 348 )
High field magnetization and thermomagnetic effects in the as-quenched and heat treated Fe78Nd16B6 alloys at different annealing temperatures and time are reported. There are two Curie temperatures to the as-quenched sample. The temperature dependence of coercivity shows a maximum at around 180K for the as-quenched and heat treated samples. A coercive field of 14.8kOe and an energy product of 10MGOe are obtained at romm temperature by annealing at 600°C for 5min. Studies of magnetic anomaly at lower temperature have also been carried out.

OBSERVATIONS OF PHONON FOCUSING IN X-CUT QUARTZ CRYSTAL
BAI Yu-hai
Chin. Phys. Lett. 1985, 2 (7): 305-308 .  
Abstract   PDF(pc) (36KB) ( 306 )
In the time-of-flight experiment with X-cut quartz crystal, in addition to the normal phonon pulses of L, TI and T2 mode, a pulse of oblique mode was observed, which can be explained according to the phonon focusing effect.

THE EFFECTS OF TRANSVERSE RELAXATION AND OPTICAL PUMPING ON THE RESONANCE FLUORESCENCE
TAN Wei-han, ZHANG Wei-ping*
Chin. Phys. Lett. 1985, 2 (7): 309-312 .  
Abstract   PDF(pc) (58KB) ( 442 )
Although the resonance fluorescence spectrum of coherent light scattering from a two-level atom has been discussed in many papers, the effects of longitudinal, transverse relaxation and optical pumping have not yet been considered simultaneously in the motion equations. By solving the optical Bloch equations including the longitudinal relaxation time T1, transverse relaxation time T2 and optical pumping parameter Δ0, in the case T2/T1«1, we obtain the spectrum with dip in the central peak besides the familiar spectrum of three peaks. In addition, we find that the parameter Δ0 and detuning Δω have influence on the symmetry, height and width of the spectrum of the three peaks.



THE FINE STRUCTURE AT 11.52MeV LEVEL IN 24Mg OBTAINED BY γ RESONANT ABSORPTION METHOD
GUO Zhen-di, GU Xi-liang, HU Yiu-de, QIAN Jin-hua, CHEN Zen-quo, GU Mu, YANG Fu-jia
Chin. Phys. Lett. 1985, 2 (7): 313-316 .  
Abstract   PDF(pc) (40KB) ( 342 )
The γ resonant absorption method has been used to determine the parameters of the 11.5MeV level in 24Mg. Two dips were observed beyond our expectations. They are identified as the resonant absorptions caused by the splitting energy levels at 11.52MeV. The energies of the corresponding states are 11519.8±0.4keV and 11520.7±0.4keV with 22.6±3.4eV and 10.0±2.9eV total level widths respectively. The fine structure and the relevant parameters of 11.52MeV state in 24Mg are given for the first time. The potential of the high resolution in the resonant absorption methodic clearly demonstrated in present paper.

EFFECT OF HEAVY DOPING ON THE OPTICAL SPECTRA OF SILICON
CHEN Chen-jia*, A. Borghesi, G. Guizzetti, L. Nosenzo, E. Reguzzoni, A .Stella
Chin. Phys. Lett. 1985, 2 (7): 317-320 .  
Abstract   PDF(pc) (57KB) ( 460 )
In this paper reflectance (R) and thermoreflectance (TR) spectra in heavily doped silicon concerning both interband and intraband transitions are reported and discussed. The heavily doped sample shows a red-shift and lifetime broadening in the two singularrities E1 (~3.4eV) and E2(~4.5eV). The values of the scattering time τ extracted from the reflectivity fit are obtained and compared with those obtained from Hall mobility measurements.

THE PHASE STRUCTURE FOR TWO PARAMETER ACTIONS IN SU(2) LATTICE GAUGE THEORY
CHEN Tian-lun, HUANG Wu-qun
Chin. Phys. Lett. 1985, 2 (7): 321-324 .  
Abstract   PDF(pc) (48KB) ( 337 )
The variational method has been applied to investigating the phase diagrams of the two parameter actions containing TrU (P)3 term in SU(2) lattice gauge theory. The result is in agreement with that obtained by Monte Carlo simulations. This can be helpful to understand the mechanism of the phase transitions.

DETERMINATION OF THE SPIN COUPLING CONSTANTS IN THE 87Rb 129Xe VAN der WAALS MOLECULE
ZENG Xi-zhi
Chin. Phys. Lett. 1985, 2 (7): 325-328 .  
Abstract   PDF(pc) (55KB) ( 508 )
The measurement of the ratio of the repolarization signal to the optical pumping signal of the Rb atoms has been used to determine the ratio  of the spin rotation coupling constant to the spin exchange coupling constant of the 87Rb 129Xe Van der Waals molecule. The value  = 3.4±0.1 is inferred from these studies. The author has also given the magnitudes of the spin rotation and spin exchange interactions.
A QUANTUM MECHANICAL DESCRIPTION FOR QUASI-LANDAU RESONANCES
ZHANG Yu, ZHANG Cheng-xiu (C.H. Chang)
Chin. Phys. Lett. 1985, 2 (7): 329-332 .  
Abstract   PDF(pc) (54KB) ( 388 )
We succeed in solving quantum-mechanically the problem of a hydrogen atom in a strong magnetic field in the (r, ρ, Ф ) coordinate system in which the main part of the Hamiltonian can be solved by separation of variables. The theoretical energy spectrum agrees to a certain extent with the experimental one.

CALCULATION OF RELATIVE SENSITIVITY FACTOR IN AUGER ELECTRON SPECTROSCOPY
ZHANG Ren-ji, CHU Sheng-lin, WU Zi-qin*
Chin. Phys. Lett. 1985, 2 (7): 333-336 .  
Abstract   PDF(pc) (65KB) ( 373 )
In this paper, the formula for calculating elemental relative sensitivity factor (S factor) has been deduced using the revised “full diffusion” model of electron scattering1. The calculated curves of S factors lie between the experimental curves obtained from the differential spectra2 and the integral spectra3.


12 articles