Volume 3 Issue 4

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Original Articles
FISSION-LIKE ESTIMATE FOR THE EMISSION OF HEAVY CLUSTERS
PAN Zhengying, YUAN Zhushu, YANG Fuchia
Chin. Phys. Lett. 1986, 3 (4): 145-148 .  
Abstract   PDF(pc) (49KB) ( 416 )
The exotic radioactive decay mode, in which a heavy cluster is emitted, is considered as a fission-like process. The potential barrier associated with an axially symmetric shape distortion is calculated in terms of the interplay between the surface and the coulomb energies. The experimental branch ratios of 14 C and 24Ne emissions to α-decays have been reproduced within about one power of ten, and some new kinds of radioactivities may be expected.


BLOCKING EFFECT ON THE NUCLEAR SPIN-ALIGNMENT
WU Chongshi, ZENG Jinyan
Chin. Phys. Lett. 1986, 3 (4): 149-152 .  
Abstract   PDF(pc) (55KB) ( 497 )
The even-odd difference in the spin-alignment is investigated. The results show, that the blocking effect, which is very hard to treat in the usual CSM, is very important.
ON THE CRITERION OF ADIABATICITY IN THE COUPLED MODE THEORY
SHANG Erchang, WANG Yunyu
Chin. Phys. Lett. 1986, 3 (4): 153-156 .  
Abstract   PDF(pc) (46KB) ( 453 )
In the present paper, it is pointed out that there are two catagories of adiabatic approximation. within the propagation distance the range-dependent variation of the waveguide may be accummulative (1) or nonaccummula-tive (2). The well-known criterion given by Milder is applicable for the first catagory. The criterion for the second catagory has been derived by the present authors. Two example are discussed, (1) a shallow water waveguide with slight surface roughness and (2) a shallow water waveguide with range-dependent sediment properties.
ELECTRONIC STRUCTURE OF (B3O6) -3 CLUSTER AND ULTRAVIOLET ABSORPTION OF β-BaB2O4 CRYSTALS
HUANG Jin, WANG Dingsheng
Chin. Phys. Lett. 1986, 3 (4): 157-160 .  
Abstract   PDF(pc) (52KB) ( 464 )
The electronic structure and the electric dipole matrix elements of (B3O6) -3 cluster are calculated by multiple scattering Xα(MSXα) method. The ultraviolet absorption of β-BaB2O4 crystal is determined from the above calculation, and the absorption edge (about 2000Å) thus estimated is in good agreement with the experimental measurement.
AMALGAMATION OF PERIODIC AND CHAOTIC SOLUTIONS IN A DOUBLE PARALLELCONNECTED LORENZ SYSTEM
ZOU Chengzhi
Chin. Phys. Lett. 1986, 3 (4): 161-164 .  
Abstract   PDF(pc) (44KB) ( 671 )
With increasing Rayleigh number in a double parallel-connected Lorenz system, it is found numerically that the coexisting periodic and chaotic solutions approach each other gradually and collide at last. In fact, the periodic solution is swallowed by the chaotic one without undergoing any bifurcation.
OPTICAL SUM-FREQUENCY GENERATION IN TRANSMISSION WITH TWO COUNTERPROPAGATING SPWs
CHEN Zhan, LIU Yajun, WANG Wencheng, ZHENG Jiabiao, ZHANG Zhiming
Chin. Phys. Lett. 1986, 3 (4): 165-168 .  
Abstract   PDF(pc) (48KB) ( 557 )
The enhancement of optical sum-frequency generation (SFG) is calculated in Kretschmann's ATR configuration with the excitation of two counter-propagating SPWs. The experimental result is in good agreement with the theoretical calculation.
GROWTH AND OPTICAL PROPERTIES OF Li2NH4 ( IO3)3 SINGLE CRYSTAL
LÜ, Mengkai, YIN Xin, ZHANG Jianguo
Chin. Phys. Lett. 1986, 3 (4): 169-172 .  
Abstract   PDF(pc) (54KB) ( 513 )
Li2NH4 ( IO3)3 single crystal with dimension of 14x14x27mm3 has been grown by cooling method. The cell parameters measured by four-cycle diffractometer are: a=11.317Å , b=ll.066Å , c=8.330Å, β=111. 25°. The infrared absorption spectrum, transmission curve and refractive index have also been measured for the first time.

FRACTAL STRUCTURES OF INTERFACE OF ZINC AND CADMIUM METAL LEAVES FORMED BY ELECTRODEPOSITION
WANG Liangyu, ZHAO Huimin, OUYANG Zhongcan*
Chin. Phys. Lett. 1986, 3 (4): 173-176 .  
Abstract   PDF(pc) (55KB) ( 511 )
Two-dimensional zinc metal leaves and cadmium metal leaves have been grown by electrodeposition. The experiment shows that the metal leaves have a characteristic scaling property of interface dimension C besides their Hausdorff dimension D. Analysing these two leaves, we find that both the number of sites N of the leaves and the number of sites adjacent Na, which is not belonging to the interfaces of the leaves, i.e., the number of nearest-neighbors follow a power-law with the radius of gyration Rg as the variable ,i.e., N=RDg and Na = RCg where D~1.60, C~1 .55.
SURFACE RECONSTRUCTION OF Si(001) STGDIED BY SLAB DYNAMICAL CALCULATION
HU Genyou, ZHANG Kaiming
Chin. Phys. Lett. 1986, 3 (4): 177-180 .  
Abstract   PDF(pc) (49KB) ( 557 )
The Si(001) surface is studied by the stab dynamical calculation using Keating model with the inclusion of an anisotropic pair interaction between surface atoms. T=0 phase diagram is obtained by diagonalizing the slab matrix numerically. Detailed information of the S(001) surface reconstructive structure is afforded and to be compared with experiments.

SECOND HARMONIC GENERATION IN LiTaO3 CRYSTALS WITH MODULATED STRUCTURE
FENG Duan, WANG Wenshan, ZOU Qun, GENG Zhaohua
Chin. Phys. Lett. 1986, 3 (4): 181-184 .  
Abstract   PDF(pc) (71KB) ( 454 )
A radio-frequency heating Czochralski technique to obtain LiTaO3 crystals with modulated structure (periodic lamina of ferroelectric domains) is first presented. The alternation of the ferroelectric domains whose half-period nearly corresponds to the coherence length LC has been achieved. Quasi-phase-matching for the nonlinear coefficient d33 has been first realized using 1.06μm Nd:YAG laser in crystals LiTnO3.
SOURCE DEPTH ESTIMATION IN WAVEGUIDE BY USING THE ORTHOGONAL DECOMPOSITION METHOD
SHANG Erchang, WANG Yunyu
Chin. Phys. Lett. 1986, 3 (4): 185-188 .  
Abstract   PDF(pc) (42KB) ( 482 )
A high-resolution method of source depth estimation in waveguide is proposed. The method is based on the mode filtering to get a data set consisting of eigenfunctions, and then the orthogonal decomposition technique is used to process this data set. Highresolution depth estimation is obtained even for the shortest data length-only two mode eigenfunctions.
PULSAR SUPERNOVA REMNANT CORRELATION
A. Qadir, M. Rafique
Chin. Phys. Lett. 1986, 3 (4): 189-192 .  
Abstract   PDF(pc) (40KB) ( 388 )
A formula is provided to check the correlation of pulsars and supernova remnants, using only observable pulsar parameters. The validity of this formula depends on the assumption that the value of the initial pulsar frequency is much greater than the present value. A test for this assumption is suggested.
12 articles