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Vol. 26, No. 5 (1977)

1977-03-05
CONTENT
EXPERIMENTAL INVESTIGATION OF THE MECHANISM OF CAVITATION EMULSIFICATION EMPLOYING HIGH-SPEED PHOTOGRAPHY
WANG CHENG-HAO, ZHANG DE-JUN, ZONG JIAN
1977, 26 (5): 381-388. doi: 10.7498/aps.26.381
Abstract +
In this work results are given for the experimental investigation of the me-chanism of cavitation emulsification by means of high-speed photography. The results show that: 1) Two fundamental types of cavitation emulsification occur simultaneously at the moment of a single cavitation bubble collapse. It thus appears that: emulsifica-tion is induced by the shock waves generated in liquids at the moment of cavitation bubble collapse; 2) In contrast with the "suction" model suggested by Nedouzhii, the process of cavitation emulsification would be better described by a "crushing" model.
ON-LINE AUTOMATIC RECOGNITION OF SPOKEN SOUNDS BY A PATTERN MATCHING METHOD
YU TIE-CHENG
1977, 26 (5): 389-396. doi: 10.7498/aps.26.389
Abstract +
A model for speech recognition by computer is suggested. In which a new method of pattern normalization in the time domain is presented. A program for recognizing spoken sounds has been developed on a Varian 620/L computer. Finally, a set of ex-perimental results is given, the correct recognition rate being grater then 99%. It is shown that this new method can be used in certain automatic control systems.
SEMI-LEPTONIC DECAYS OF THE BARYONS AND HIGH-ENERGY NEUTRINO REACTIONS IN THE STRATON MODEL
RUAN TONG-ZE, LI BING-AN
1977, 26 (5): 397-410. doi: 10.7498/aps.26.397
Abstract +
On the basis of the structural model of stratons, we discuss semi-leptonic decays of (1/2)+ baryons and elastic and quasi-elastic neutrino reactions, using the effective Ha-miltonian of weak interaction for stratons and leptons in [1] and the (1/2)+ baryon wave functions in [2] and the parameters determined by electromagnetic processes in [3]. The theoretical results of the semi-leptonic decays are in good agreement with the experimental results. The axial-vector form factor of △S = 0 processes and the total cross-sections of νμ+n→p+μ- agree with experiments within reasonable error. The axial-vector form factor of △S = 1 processes and the total cross-sections of νμ+p→Λ+μ+ also agree with the rough experimental data available.In particular, it is of interest to point out that, in our discussion, all the parame-ters involved were determined in [3], no new parameter has been introduced.
A MICROSCOPIC THEORY OF THE JOSEPHSON EFFECT IN SUPERCONDUCTING BRIDGES
LIU FU-SUI
1977, 26 (5): 411-416. doi: 10.7498/aps.26.411
Abstract +
The empirical formula j=Σn jnsin nφ for a superconducting Dayem bridge is proved using Green's function and the two-gap model of the bridge. A quantitative explanation for the observed height of the microwave induced step is presented. This paper also gives the sufficient condition for the empirical formula of a superconduc-ting bridge, and the dependence of Josephson current density on bridge length is discussed.
ON A GENERALIZED OHM'S LAW IN PARTIALLY IONIZED PLASMA
LU QUAN-KANG
1977, 26 (5): 417-426. doi: 10.7498/aps.26.417
Abstract +
In this paper, a generalized Ohm's Law of unsteady state in partially ionized plasma is derived. Various appropriate expressions under concrete physical conditions are analysed. When plasma approaches fully ionization, the generalized Ohm's Law reduces to the form given by Spitzer; and when partially ionized plasma reaches steady state, the generalized Ohm's Law reduces to the form given by Cowling and Любимов. Finally, this Ohm's Law is applied to certain problems on plasma a. c.resistivities, dispersion relations and diffusions, etc.
PHYSICAL METHOD OF GROUP REPRESENTATION THEORY (Ⅱ)——THE QUASI-STANDARD BASES OF PERMUTATION GROUP AND THE GELFAND BASES OF UNITARY GROUP
CHEN JIN-CHUAN, WANG FAN, GAO MEI-JUAN
1977, 26 (5): 427-432. doi: 10.7498/aps.26.427
Abstract +
This paper analyses the contradictions which would appear when one applies the traditional theory of group repesentation to gf-the permutation group on state indicies. It is pointed out that when repeated state indicies occur, the permutation operator of gf will become undefined. According to [1], we generalise naturally the concepts of the irreducible bases for such case and give a unambiguous definition of the so called quasi-standard bases of group gf. Futhermore we have proved that the quasi-standard bases of group gf are just the Gelfand bases of group SUn. Hence the eigenfunction methodcan also be used to calculate the Gelfand bases of group SUn.
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