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Volume 3 Issue 8
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Original Articles
DEPTH PROFILES OF BROMINE IN 79Br+ ION IMPLANTED Pb1-xSnxTe OBTAINED BY SIMS MEASUREMENT AND THEORETICAL CALCULATION
XIA Yueyuan(Y.Y.HSIA), TAN Chunyu, WANG Yihua, HU Xierong*, XU qianwei**
Chin. Phys. Lett. 1986, 3 (8): 337-340 .  
Abstract   PDF(pc) (44KB) ( 346 )
The depth profile of Br in 79Br+ ion implanted lead-tin-telluride, Pb1-xSnxTe, was obtained by secondary ion mass spectrometry(SIMS). The SIMS profile has been compared with that obtained by our theoretical calculation, in which a more realistic interatomic potential and reasonable electronic stopping power were used. The SIMS result agrees well with the theoretical calculation.

PHASE CONTENT AND ATOMIC STRUCTURE DETERMINATION IN TWO-PHASES SYSTEMS BY EXAFS
LU Kunquan*, WAN Jun**, JIANG Wei*
Chin. Phys. Lett. 1986, 3 (8): 341-344 .  
Abstract   PDF(pc) (39KB) ( 361 )
A method of EXAFS analysis to determine phase content and local structure surrounding same type atoms in different phase of a mixed phases system is proposed. A general expression of (k) function for a two phases system is presented. To verify the method, the EXAFS of some specimens were measured and analyzed. The results agreed well with expected ones.
MEASUREMENT OF THE ANGULAR DISTRIBUTION OF GAMMA RAYS EMITTED IN THE THREE PHOTON ANNIHILATION OF POSITRONS AND ELECTRONS
YOU Ke, TANG Xiaowei, YANG Baozhong, LI Yaoqing
Chin. Phys. Lett. 1986, 3 (8): 345-348 .  
Abstract   PDF(pc) (50KB) ( 402 )
We have measured the angular distribution of gamma rays emitted in three photon annihilation of positrons and electrons by the triple fast coincidence method. The experimental data are in agreement with the quantum electrodynamics (QED) prediction within the error.


OBSERVATION OF CHAOTIC NOISE IN Nb-In POINT CONTACT
TAO Hongjie, LU Li, YANG Qiansheng
Chin. Phys. Lett. 1986, 3 (8): 349-352 .  
Abstract   PDF(pc) (54KB) ( 428 )
For the first time, the chaotic noise in point contact has been investigated in the presence of dc current and rf radiation. The I-V characteristics and the corresponding rms noise voltage are measured simultaneously. Two types of modes of chaotic noise can be identified. Interesting feature of the intermittent chaotic noise has been observed.
STRUCTURE MODEL WITH m35 SYMMETRY AND 12 COORDINATES
GAO Chen, DUAN Jianzhong, LIU Da, LIU Wenhan, WU Ziqin
Chin. Phys. Lett. 1986, 3 (8): 353-356 .  
Abstract   PDF(pc) (46KB) ( 410 )
Taking into consideration of the main results observed in Al-Mn quasicrystal, we suggest a structure model with m35 symmetry. The grain of quasicrystal can grow up with definite Al and Mn sites and Al:Mn ratio. All atoms in this model have 12 coordinates and all neighboring distances are suitable. Especially, the density deduced from it is in good agreement with experiment.
THE INVARIANT DISTRIBUTION OF NON-FULLY DEVELOPED CHAOS FOR THE TENT MAP
YU Jiang, HU Gang
Chin. Phys. Lett. 1986, 3 (8): 357-360 .  
Abstract   PDF(pc) (46KB) ( 348 )
The invariant distribution of non-fully developed chaos has been investigated for the tent map. A very sophisticated sequence set which corresponds to exact solutions of the invariant distribution has been found, as a special case, the MSS (Metropolis-Stein-Stein) sequence is also included in this sequence set.
AN ADVANCED CONCEPT FOR FUSION REACTOR DEVICE
TSAI Shihtung(CA Shidong), CHEN Yanping, GUO Shichong, KE Fujiu, SHEN Jiewu, XU Minjian, YU Xuehua, ZHOU Yumei, CHEN Yunming, WANG Shi jin, ZHANG Chunyuan
Chin. Phys. Lett. 1986, 3 (8): 361-364 .  
Abstract   PDF(pc) (50KB) ( 385 )
Combining the merits of linear and toroidal confiprations with the fast and slow process concepts, we consider a fusion reactor concept consisting of two axisymmetric tandem mirrorlike sections and two heliac stellarator U-bends. The D-D reactor parameters are presented. The radio frequency (RF), energetic components and the plugs are needed only at the startup phase. These greatly cut down the coat and relax the technical requirements of engineering.

A NONLINEAR CONTINUOUS MEDIUM MODEL OF DISLOCATION AND ITS STRESS, STRAIN AND DISPLACEMENT FIELDS
FAN Tianyou
Chin. Phys. Lett. 1986, 3 (8): 365-368 .  
Abstract   PDF(pc) (40KB) ( 439 )
This study offers a model of dislocation in power law hardening medium and gives the mathematical expressions of its stress, strain and displacement fields, whose structure is governed by hardening exponent N. The well-known classical solution of Volterra and Burgers is a special case of this model when N=I.
THE E2 EFFECTIVE CHARGE IN LOW-ENERGY NEUTRON RADIATIVE CAPTURE
HO Yukun
Chin. Phys. Lett. 1986, 3 (8): 369-372 .  
Abstract   PDF(pc) (45KB) ( 380 )
It is shown that the concept of effective charge can be used to explain low-energy neutron E2 radiative capture. The quantitative analyses of the 13C(n, γ) at 0.1529MeV resonance and 20Ne(n, γ), 25Mg(n, γ) at thermal energy illustrate that an effective charge equal to 0.5e is required to explain the measured data. This value is consistent with that used for bound state to bound state E2 transition in the same mass region.


STUDY OF ANOMALIES NEAR 75°C IN LiNbO3 BY X-RAY DIFFRACTION
ZHOU Hengnan, SHEN Huimin, YUAN Fang, QIU Dirong, WANG Yening
Chin. Phys. Lett. 1986, 3 (8): 373-376 .  
Abstract   PDF(pc) (59KB) ( 454 )
The anomaly of LiNbO3 in the vicinity of 75°C has been studied by various X-ray diffraction methods. An abrupt change of axial ratio (c/a) was measured, which may be ascribed to alternate rotation of NbO6 octahedron about c axis. No change of structure symmetry was observed.
THEORY OF “CLUMPS” IN DRIFT-WAVE TURBULENCE IN TOKAMAK PLASMA
WANG Xiaogang, QIU Xiaoming *
Chin. Phys. Lett. 1986, 3 (8): 377-380 .  
Abstract   PDF(pc) (31KB) ( 369 )
Basing on the new method of trajectory stochastic treatment advanced by one of the authors of this paper, the theory of “clumps” in drift -wave turbulence in tokamak plasmas has been developed. It is shown that, as a longer time behaviour, plasmas in tokamaks will have the same “clumps” effects as those in uniform magnetic fields, although the diffusion crossing magnetic field Lines in tokmaks will be enhanced. The influence of the non-uniformity of the magnetic field, such as curvature, shear, etc., on the transverse diffusion and the “clump” life-time is discussed.


BACKSCATTERING AND CHANNELING STUDY OF ZINC IMPLANTED SILICON
YIN Shiduan, GU Quan, ZHANG Jingping, ZHANG Qichu, LIU Jiarui
Chin. Phys. Lett. 1986, 3 (8): 381-384 .  
Abstract   PDF(pc) (36KB) ( 414 )
The depth of the amorphous-crystalline interface for 1 x 1015 to 1x1017Zn/cm2 ions in silicon has been measured by high resolution backscattering technique. The variation of this interface depth with fluency is found to agree well with the creation and overlap model of the simple direct amorphous zone.

12 articles