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Vol. 23, No. 3 (1974)

1974-02-05
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CONTENT
1974, 137 (3): 1-2. doi: 10.7498/aps.23.1
Abstract +
MEASUREMENT OF THE DETECTION IMPEDANCE AND A DESIGN FOR INCREASING THE SENSITIVITY OF THE DETECTOR IN THE ACOUSTIC IMPEDANCE METHOD
LI MING-XIAN
1974, 137 (3): 3-12. doi: 10.7498/aps.23.3
Abstract +
A simple method is devised for measuring the detection impedance in the acoustic impedance method of detection of unbonds and is based on an equivalent circuit of the detector. On the basis of the measured detection impedance, theoretical exploration is directed toward increasing the detection sensitivity for an unbond by properly choosing some of the detector parameters. The theoretical analysis is found to agree fairly well with the experimental results. In the case of unbond detection the sensitivity is increased by 5 times or more.
CLASSIFICATION OF WAVE FUNCTIONS IN A MANY NUCLEON SYSTEM BY A ROTATION GROUP METHOD
REN GENG-WEI
1974, 137 (3): 13-25. doi: 10.7498/aps.23.13
Abstract +
In this paper we have given a projection operator method, which is used to classify wave functions in a many nucleon system. We have also given the results of the classification coefficients for A = 1 to 3.
AGING STRUCTURE OF MARAGING STEEL
CAI QI-KONG, ZHU JING, HE CONG-ZHI
1974, 137 (3): 26-41. doi: 10.7498/aps.23.26
Abstract +
Transmission electron microscopy and electron diffraction studies were carried out in order to clarify the crystallographic properties of strengthening precipitates and aged structure in an 18Ni maraging steel.By using various zonal diffraction patterns, the co-existence of the precipitates Ni3Mo, Ni3Ti and the dispersed reverted austenite was identified, and their orientation relation-ships with respect to the martensite matrix determined.It was shown that the close-packed plane and direction of the precipitates and the reverted austenite are parallel to those in the matrix. The Widmanst?ttentype morphology in the transmission electron micrographs of the aged structure is in fact a three-dimensional skeleton structure in which the length direction of the rod-like precipitates is parallel to one of the four directions of the matrix. The true existence of the observed extended and piled-up dislocations needs further experimental verifications.The process of precipitation along dislocation lines is discussed and a possible mechanism of the cobalt-molybdenum interaction is proposed from the structural point of veiw.
THE ELECTRONIC STRUCTURE AND ABSORPTION SPECTRA OF THE TETRAHEDRAL HALIDE COMPLEXES OF Cu(II)
DU YOU-MING, LIANG JIA-CHANG
1974, 137 (3): 42-51. doi: 10.7498/aps.23.42
Abstract +
Crystalline field energy levels of central ion and lingands for complex ions CuX4--(X = Cl, Br) were given. By considering the crystalline field effect, and by using the modified Wolfsberg-Helmholz 's molecular orbital approximation, the energies for the ground state and some of the excited states of these complex ions were calculated. The calculation results are in agreement with the features of the observed lingand field transition bands and electron-transfer spectra.
CALCULATION OF NEUTRON CAPTURE CROSS SECTIONS OF Th232 AND U238
FU DE-JI, CAI YAN-HUANG, XIA KE-DING
1974, 137 (3): 52-60. doi: 10.7498/aps.23.52
Abstract +
Neutron Capture cross sections of Th232 and U238 before the opening of fission channels are calculated by Statistical theory. The influences of Optical potential parameters, Gamma radiation widths, Nuclear temperature and the Statistical width fluctuation correction factor are illustrated and discussed.
MEASUREMENT OF THE DIELECTRIC CONSTANTS AND THE PERMEABILITIES OF MICROWAVE FERRITES
SHI LONG-PEI, LIAO SHAO-BIN
1974, 137 (3): 61-72. doi: 10.7498/aps.23.61
Abstract +
The imaginary part of the dielectric constant ε" and of the permeability μ" of the sample were determined by measuring the change of reflection coefficient of a resonance cavity of the reflection type with and without the sample in it. The effects of the shape of the sample and its location in the cavity on the measurement were investigated. The sensitivity of the measuring system was high. By raising the quality factor of the cavity, adjusting it to approach critical coupling, and appropriately choosing a cavity of smaller volume, it should not be difficult to measure the loss factor with this set of measuring devices to an accuracy of the order of 10-5.