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Volume 6 Issue 9
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Original Articles
EXTRA Z BOSONS, FAMILIES AND HEAVY FERMIONS
LI Tiezhong
Chin. Phys. Lett. 1989, 6 (9): 385-388 .  
Abstract   PDF(pc) (52KB) ( 371 )
The minimal grand unified theories with three-family should include two extra Z bosons which belong to the different broken scales. Georgi's argument on heavy Dirac fermions has been realized. These fermions should be not bizarre.

IS THE THERMAL DILEPTON SPECTRUM A SIGNATURE FOR DIAGNOSING FIRST-ORDER DETONATION QCD PHASE TRANSITION?
SHEN Jianguo, QIU Xijun
Chin. Phys. Lett. 1989, 6 (9): 389-392 .  
Abstract   PDF(pc) (58KB) ( 367 )
Detonation has two different scenarios: the Gyulassy's scenario and the Kapusta's one. The dilepton production rate in the Kapusta's scenario is calculated. Associated with the Gyulassy's scenario, the peculiar property of the spectrum and its dynamical origin in the detonation phase transition are discussed and analyzed. Its spectrum is not a signature for diagnosing the detonation phase transition.
A MODEL EQUATION AND ITS EXACT TWO DIMENSIONAL SOLITARY WAVE SOLUTIONS FOR WATER WAVE DYNAMICS
HUANG Guoxiang, LOU Senyue, DAI Xianxi, YAN Jiaren*
Chin. Phys. Lett. 1989, 6 (9): 393-396 .  
Abstract   PDF(pc) (51KB) ( 436 )
Using the method of multiple scales and considering the nearly two-dimensional modulation of the waves when the dimensionless surface-tension coefficient τ of fluid is close to 1/3, we proposed a new model equation which we call the higher-order KP equation for water wave dgnamics. The exact and explicit two dimensional solitary wave solutions are also given.
WHAT CAUSE THE NONPROPAGATING SOLITONS TO MOVE
WANG Benren, WEI Rongjue
Chin. Phys. Lett. 1989, 6 (9): 397-400 .  
Abstract   PDF(pc) (48KB) ( 320 )
Two spherical solitons are vibrating along the direction perpendicular to a line joining the cores of them. The interactive forces that will be attractive or repelling depending on their phase are given.
ELECTRIC HEXADECAPOLE OF 3d ELECTRON CLOUD OF Ti3+ ION
MAO Xian
Chin. Phys. Lett. 1989, 6 (9): 401-404 .  
Abstract   PDF(pc) (56KB) ( 299 )
The concept of electric hexadecapole is adopted to d electron clouds of transition metal. By analogous treattment of nuclear electric hexadecapole interaction with the surrounding electric field, the ligand field splittings of d orbitals is the electric hexadecapole splittings. The electric hexadecapole moment of 3d electron cloud of Ti3+ ion has been evaluated as 2.5x10-50C.m4.
THE TEMPERATURE DEPENDENCE OF THE PHOTOCONDUCTIVITY IN a-Si:H/a-SiNx:H SUPERLATTICES
ZHU Meifang, SONGJun, LI Chenxi*
Chin. Phys. Lett. 1989, 6 (9): 405-408 .  
Abstract   PDF(pc) (61KB) ( 281 )
The temperature dependence of the photoconductivity σp(T) in a-Si:H/a-SiNx:H superlattices does not decrease with temperature decreasing in the range of 120-250K, but it is temperature independent showing a wide plateau of photoconductivity σp in the superlattices with thickness of a-Si:H layer dsi=12 and 57nm. The plateau of σp(T) depends on the light intensity. One type of interface state as sensitizing centre was proposed. The parameters of the sensitizing centre were determined by using computer fitting of σp(T). The computed results are the same with the experimental data.


PREPARATION OF THE Bi-Sr-Ca-Cu-O SUPERCONDUCTING FIBERS
MAO Sining, HUO Yujing*, HUANG Hesheng, LIU Menglin, ZHOU Heping**, WANG Ying, HUANG Zhelin, BO Naibing, LIN Song, ZHANG Kongshi
Chin. Phys. Lett. 1989, 6 (9): 409-412 .  
Abstract   PDF(pc) (100KB) ( 408 )
Bi-Sr-Ca-Cu-O superconducting fibers have been successfully prepared by means of the laser-heated pedestal growth method. The superconductivity of the fiber sample is closely related to the composition of source material, the power of focused laser beams, the pull rate of growing fiber, and the condition of post-annealing. The typical size of samples is 150μm x30mm. The onset of transition was 118K, and zero resistance was 85K. The majority phase in the fibers is the 85K (2-2-1-2) phase of the Bi-Sr-Ca-Cu-O materials. Samples are stable and reproduceable.




PRECIPITATION AND DEFECTS IN Nb-CONTAINING NdDyFeCoB MAGNETS
LIU Jinfang, RAO Xiaolei, ZHANG Nanning, LUO Helie
Chin. Phys. Lett. 1989, 6 (9): 413-416 .  
Abstract   PDF(pc) (95KB) ( 349 )
The microstructure of Nb-containing NdDyFeCoB magnets has been investigated using transmission electron microscope. Very small particles whose diameters are about several to 40Å have been found in as-sintered magnets. It may be formed by self-tempering. Dislocations and stacking faults have been found inside grains. It seems that the increase of coercive field in Nb-containing magnets is closely related with defects and precipitations.
RELAXATION PROCESS IN COBALT-FERRITE EPITAXIAL IRON OXIDES
SUN Ke, XU Junhao, LIN Mingxi, CHEN Guanmian, LUO Helie
Chin. Phys. Lett. 1989, 6 (9): 417-420 .  
Abstract   PDF(pc) (62KB) ( 344 )
The migration process of Co ions in the cobalt-ferrite epitaxial layer on γ-Fe2O3 powder has been studied by magnetic thermal annealing method. The activation energy E and coefficient A of Co ions have been measured. An abnormal increase of coercivity of sample annealed in a transverse magnetic field was found. On the basis of Mössbauer and XPS results the reason of this phenomenon is discussed.
THEORY OF RESONANT MICROWAVE ABSORPTION OF DNA IN AQUEOUS SOLUTION
ZHANG Chunting, ZHOU Genfa
Chin. Phys. Lett. 1989, 6 (9): 421-424 .  
Abstract   PDF(pc) (50KB) ( 685 )
The Ostrovskii-Sutin equation of the longitudinal displacement of an elastic rod has been derived for a DNA chain by taking its structure into account. The perturbation solution of this equation shows that the resonant microwave absorption by DNA in solution is possible. In addition to the primary resonance at ωn, our theory predicts also a subharmonic resonance at ωn / 2 . The strength of the latter is proportional to l-3, where l is the length of DNA chain.

THE LOOP COSMOLOGICAL CONSTANT IN COMPACT SPACE S1 AND MODULI SPACE F=C+/SL(2,Z)
YAN Jun, LI Jiangnan, HU Shike
Chin. Phys. Lett. 1989, 6 (9): 425-428 .  
Abstract   PDF(pc) (54KB) ( 518 )
The one-loop string cosmological constant has been calculated by ξ functicn regularizing method. For Wess-Zumino a model, we find the bosonization temperature being less than the critical temperature in compact space S1. The similar properties in moduli space C+/SL(2, Z) are also discussed.
QUANTUM INFLATIONARY MODEL AND THE UNCERTAINTY OF THE HUBBLE SIZE
ZHANG Shiwei
Chin. Phys. Lett. 1989, 6 (9): 429-432 .  
Abstract   PDF(pc) (56KB) ( 518 )
A quantum inflationary universe model is proposed, in which the expansion factor S(t) is treated as a q-number, and the cosmological constant A is identified with the energy density of Higgs field. Moreover, the initial quantum state is assumed to be a Gauss wave pocket. In such framework, < S 3/2> follows the classical de-Sitter expansive law. The relative quantum uncertainty of Hubble size lH(t) = (S/S)-1 was computed: ΔlH(t) / < l H(t)>~Z-6, where Z is the inflationary factor of universe. This result is basically different from that of Padmanabhan; the discrepency was explained. We conclude that the quantum Hubble size is practically a classical quantity.




12 articles