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Volume 5 Issue 9
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Original Articles
THE Bi-Sr-Ca-Cu-O BULK SUPERCONDUCTORS WITH RESISTANCE CLOSE TO ZERO ABOVE 110K
MAO Sining, LIU Menglin, WU Zhenyi, HUANG Hesheng, GUO Zeng, ZHAO Xin, LIN Yaozhong, HUANG Zhelin, YU Jiali, ZHANG Kongshi
Chin. Phys. Lett. 1988, 5 (9): 385-388 .  
Abstract   PDF(pc) (63KB) ( 436 )
The bulk superconductors of the Bi-Sr-Ca-Cu-O system with resistance close to zero at the temperature above 110K have been prepared by solidstate reaction techniques. The onset of, transition is 125K. and the resistance of the bulk samples has a sharp drop (~98%) near the Tc and is close to zero at 111K. Samples show a good stability. It has been implied that completely cutting off the "resistive tail" of this bulk superconductors should be possible.
HIGH POWER TUNABLE UV LASER RADIATION PRODUCED BY SECOND-HARMONIC GENERATION IN β-BaB2O4
XU Zuyan, DENG Daoqun, ZHAO Tienan, SHOU Hansen*
Chin. Phys. Lett. 1988, 5 (9): 389-392 .  
Abstract   PDF(pc) (62KB) ( 358 )
High power tunable UV laser radiation from 2750Å to 3200Å has been obtained by second-harmonic generation in a β-BaB2O4 crystal. A maximum frequency doubling efficiency of 41% and a UV output power of 3.7MW have been obtained.
DEEP TRAPS IN a-Si:H MEASURED BY INFRARED STIMULATED CURRENT
LI Wei, HAN Daxing
Chin. Phys. Lett. 1988, 5 (9): 393-396 .  
Abstract   PDF(pc) (51KB) ( 446 )
Silicon dangling bond(DB) is widely accepted as recombination center in a-Si:H. This is true at room temperature. We measured the Infrared Stimulated Current(IRSC) in the temperature range of 86-260K. and focused on the PC onset overshoot for both undoped and P-doped samples. The results show that DB also acts as electron trap, especially at low temperature.
ANOMALOUS ION THERMAL CONDUCTIVITY INDUCED BY ▽Ti INSTABILITY
GUO shichong+, CHEN Liu++, CAI Shidong(S .T.Tsai)+++
Chin. Phys. Lett. 1988, 5 (9): 397-400 .  
Abstract   PDF(pc) (46KB) ( 437 )
The stability properties of ion temperature gradient instability are studied analytically in both weak and strong ballooning limits for toroidal geometry. The local anomalous ion thermal conductivity Xi is obtained. The scaling of this conductivity under slab approximation is consistent with the results given by Connor et al. The toroidal effects contribute an additional Pfirsch-Schlüter factor ( l+2q2)3/4 to the conductivity.

PARAMETERS FOR ARRIVAL TIME DISTRIBUTION OF AIR SHOWER PARTICLES
DAI Hongyue, W. Hazen*, E. Hazen**
Chin. Phys. Lett. 1988, 5 (9): 401-404 .  
Abstract   PDF(pc) (54KB) ( 429 )
Several parameters which could be used to describe the arrival time distribution of extensive air shower (EAS) particles have been discussed according to their relations with core distance and the fluctuations. Among these parameters, τ is considered to be better than the others when applied to Linsley Effect.
STRUCTURE AND MAGNETIC PROPERTIES OF A18.8Fe3.7Ce1 ALLOY
J.G.Zhao, L.Y.Yang, Q.Fu, H.Q.Guo
Chin. Phys. Lett. 1988, 5 (9): 405-408 .  
Abstract   PDF(pc) (45KB) ( 361 )
Paramagnetic, ferromagnetic and antiferromagnetic properties are reported for as-quenched amorphous, annealed quasicrystal and crystal Al-Fe-Ce alloys. The first ferromagnetic quasicrystal was studied. Its Curie temperature is about 340K and μ(Fe)= 2.3μB.
EFFECTIVE CONDUCTIVITY IN A TWO-PHASE MATERIAL WITH GENERALIZED CHEQUER-BOARD GEOMETRY
BAO Keda
Chin. Phys. Lett. 1988, 5 (9): 409-412 .  
Abstract   PDF(pc) (54KB) ( 331 )
In this paper an exact analytical solution of effective conductivity in a two-phase material with the generalized chequer-board geometry is obtained. They are
In(σe2)=In(R+s2/R+1),
Where
R=s(1+ s2)[2+ε(ηs2 -1)]+ s2 (s2-1)T(ε,η)/s(1+ s)2 ε(1-η)-(s-1)T(ε,η)
And T(ε,η)=Σ H(n)sinh[√λna(1-η)tan([√λnbε)/h sinh([√λna ) tan ([√λnb)
Some calculated results for a=b, n=l and s=50, 7.14 are also shown.

RAPIDITY DISTRIBUTION IN DIFFERENT MULTIPLICITY INTERVALS
ZHAO Weiqin*, PAN Jicai
Chin. Phys. Lett. 1988, 5 (9): 413-416 .  
Abstract   PDF(pc) (58KB) ( 357 )
Based on the statistical model proposed by the Berliner group, including the assumption of cluster production and considering energy conservation for each fixed total multiplicity n, good fits to the data of the rapidity distributions for different mutiplicity intervals are obtained.

RELATION BETWEEN TWO KINDS OF MOMENT OF INERTIA AND NUCLEAR TRIAXIALITY
ZENG Jinyan, HUANG Haixin, LIN Xinwei*, MENG Jie*
Chin. Phys. Lett. 1988, 5 (9): 417-420 .  
Abstract   PDF(pc) (51KB) ( 355 )
The important fact that the second kind of moment of inertia J(2) is larger than the first kind of moment of inertia J(1) can be derived naturally from the 2-parameter expression for the rotational spectra, E(I)=a(√1+bI(I+1)-1), in its derivation the nuclear triaxiality has been taken into account.
FRACTAL DIMENSION OF NUCLEIC ACID SEQUENCES AND ITS RELATION TO EVOLUTIONARY LEVEL
LUO Liaofu. TSAI Lu
Chin. Phys. Lett. 1988, 5 (9): 421-424 .  
Abstract   PDF(pc) (40KB) ( 402 )
The fractal dimension (FD) in base space of nucleic acid sequences is introduced and calculated fog 14 categories of nucleic acids. It is discovered that there exists a possible statistical relation between FDs and evolutionary levels of these sequences.
HIGH-SENSITIVITY HOLOGRAPHIC STORAGE IN Ce-DOPED STRONTIUM-BARIUM NIOBATE AT 632.8nm
YUE Xuefeng, SHAO Zongshu, CHEN Huancho, WANG Yingsu
Chin. Phys. Lett. 1988, 5 (9): 425-428 .  
Abstract   PDF(pc) (51KB) ( 344 )
We report the high-sensitivity holographic storage in Ce-doped SBN with a low power CW He-Ne laser. A maximum index change Δnmax = 1.07x10-4 a photorefractive sensitivity S=7.9 x10-4 cm2/J, and a maximum diffraction efficiency η=78% were obtained. The optical readout characteristics of holograms recorded by the sample were also studied.
Comment and Reply COMMENT ON "THE MAGNETIC SINGLE-ION ANISOTROPY IN HEMATITE"
PEI Xiedi
Chin. Phys. Lett. 1988, 5 (9): 429-432 .  
Abstract   PDF(pc) (43KB) ( 625 )
12 articles