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Vol. 25, No. 3 (1976)

1976-02-05
CONTENT
TENTATIVE OBSERVATIONS ON GRAVITATIONAL RADIATION FROM NP 0532
Lü DA-JIONG, GAO JIAN-GUO
1976, 149 (3): 181-187. doi: 10.7498/aps.25.181
Abstract +
A synchronised accumulation technique is used to achieve a resolution of up to 10-13 cm for the oscillating amplitude of a laser interferometer. Such a technique is applied to observe the 60.4 Hz gravitational radiation which is possibly emitted from the pulsar NP 0532 of the Crab Nebula. Present experiments show that no such signal is received.
THE ASYMPOTOTIC BEHAVIOR OF ELECTROMAGNETIC FORM-FACTORS OF THE NUCLEON AND CALLAN-SYMANZIK EQUATION
AN YING, WU YONG-SHI, DAI YUAN-BEN
1976, 149 (3): 188-196. doi: 10.7498/aps.25.188
Abstract +
It is shown that for the model in which nucleons couple with pseudo-scalar mesons, the homogeneous Callan-Symanzik equation can be used to investigate the asym-pototic behavior of electromagnetic form-factors of the nucleons. In this way, the leading-logarithm terms in the perturbation theory of electromagnetic form-factors of the nucleon in this model are calculated, and some more general cases are discussed.
DEEP INELASTIC ELECTRON-PROTON SCATTERING (Ⅰ)
CAO CHANG-QI, QIN DAN-HUA
1976, 149 (3): 197-214. doi: 10.7498/aps.25.197
Abstract +
The straton knocked-out diagram is investigated more strictly using the Dyson representation, to clarify: whether the scaling property can indeed be derived from this mechanism and, if so, whether the straton mass is required to be small, and what are the definite criterions for the largeness of v and q2. It is shown that, for large values of v, the straton knocked-out diagram does lead to a scaling property, but the primary result is W1 = vf1(x) and w2 = f2(x), which differs from that of Bjorken. Only by assuming the knocked-out diagram dominance (for deep inelastic scattering) and using the gauge condition, can W1 and W2 be suppressed, thus obtaining the Bjorken scaling. Furthermore, the derivation of scaling merely requires v to be large (according to some definite criterions), but places no restriction on q2. The straton mass M is also not required to be smaller than the nucleon mass. Theoretically, for an arbitrary M, the scaling property can always be derived, provided v is sufficiently large.
ON THE PERTURBATION EXPANSION OF THE QUANTIZED COMPOSITE FIELD THEORY
HE ZUO-XIU, ZHANG ZHAO-XI, HUANG TAO
1976, 149 (3): 215-225. doi: 10.7498/aps.25.215
Abstract +
A perturbation series of a quantized composite field theory which is based upon the asymptotic condition defined by the Bethe-Salpeter wave function is derived from the interaction representation. The problem of choosing graphs describing various processes in the straton model is discussed.
THE GENERATOR COORDINATE METHOD AND NUCLEAR COLLECTIVE MOTIONS (Ⅱ)——MULTIPOLE AND PAIRING EXCITATIONS IN EVEN-EVEN NUCLEI
XU GONG-OU, WANG SHUN-JIN, LIU DUN-HUAN, YANG YA-TIAN, MAO MING-DE
1976, 149 (3): 226-234. doi: 10.7498/aps.25.226
Abstract +
Nuclear collective motions are further studied using the generator coordinate-method. Multipole excitations of both spherical and deformed nuclei as well as pairing excitations of both normal and superconducting nuclei are investigated in a unified way.
A THEORETICAL ANALYSIS OF A COMPRESSED-TIME CORRELATOR FOR SIGNAL DETECTION
ZHANG SHU-YING
1976, 149 (3): 235-245. doi: 10.7498/aps.25.235
Abstract +
The theoretical problems of a compressed-time correlator are investigated from the viewpoint of signal detection. Through discussion of the LMF arid PR signals, some useful conclusions and basic formulas concerning the output signal, spectrum structure, Doppler filter set-up, noise background, SNE gain and signal envelope smoothing are obtained. As a consequence, it has been possible to design an improved sound pulse-compression receiver.
SPACE-TIME CORRELATION FUNCTION OF A NOISE FIELD IN RANDOM MULTIPATH DISPERSION CHANNELS
XU ZHEN-YONG
1976, 149 (3): 246-253. doi: 10.7498/aps.25.246
Abstract +
In this paper a model for underwater acoustic channels is established. By means of this model a general expression is derived for the space-time correlation function produced by a noise source in random multipath dispersion channels.It is shown that the spread and reduction of the correlation function are caused by the multipath propagation of sound waves and the random properties of the underwater acoustic channels. The effect of the dispersion properties of the channels on the correlation function is also discussed.
ON THE OPTIMUM COMPENSATION OF THE TEMPERATURE INSTABILITIES CAUSED BY THE MAGNETOCRYSTALLINE ANISOTROPY FIELD IN YIG MICROWAVE DEVICES
JIA WEI-YI, ZHANG PENG-XIANG
1976, 149 (3): 254-264. doi: 10.7498/aps.25.254
Abstract +
More precise analytic expressions for ferromagnetic resonance of single crystals are calculated, the approximation being carried to terms quadratic in the magneto-crystalline anisotropy field. On the basis of these, the problem of the compensation of the temperature instabilities of single crystal YIG microwave devices, caused by the variations of the anisotropy field, is discussed. Significant corrections to the temperature compensation directions that have been in use are introduced. Formulae for the calculation of the temperature characteristics of YIG devices with the applied magnetic field in the corrected compensation directions are given.
BRIEF REPORT
COMMUNICATIONS
A SIMPLE AND RELIABLE HELIUM LEVEL INDICATOR
RAN QI-ZE
1976, 149 (3): 270-270. doi: 10.7498/aps.25.270
Abstract +
A SIMPLE TYPE OF PNEUMATIC VACUUM VALVE
XIE XIN-NENG
1976, 149 (3): 271-272. doi: 10.7498/aps.25.271
Abstract +