Vol. 36, No. 2 (1987)
THE APPLICATION OF ∑ RELATIONSHIP LINEAR THEORY (Ⅰ)——THE USE OF ∑4, RELATIONSHIP IN CRYSTAL STRUCTURE DETERMINATION
1987, 36 (2): 131-139. doi: 10.7498/aps.36.131
We describe systematically the procedure to realize calculation of ∑4 relationship and its practical value for crystal structure determination. The computations for five differet crystal structures indicate that a number of O, π type semi-invarant phases with high reliability can be obtaind using ∑4 relationship. The possible applications of the procedure in crystal structure determination are discussed.
THE APPLICATION OF ∑ RELATIONSHIP LINEAR THEORY (Ⅱ)—— THE PROBLEM OF APPLICATION OF ∑7, RELATIONSHIP
1987, 36 (2): 140-148. doi: 10.7498/aps.36.140
A feasible calculation procedure of ∑7 relationship is proposed based on the ∑ relationship linear theory and tested with five known crystal structures. A comparison is made between ∑7 and ∑3 relationships and their practical value in crystal structure analysis are discussed.
1987, 36 (2): 149-156. doi: 10.7498/aps.36.149
In this paper, we analyse the chaos, steps and hysterisis in the I-V characteristics of Joseph-son junction theoretically, and obtain corresponding analytic expressions. These results are in agreement with experimental results.
1987, 36 (2): 157-164. doi: 10.7498/aps.36.157
The problem of coexistence of superconductivity and ferromagnetism in the triplet bipolaro-nic system has been studied by using the symmetry-broken Hartree approximation. It is found that the ground stare of the system is the mixed state of both orders, which is different from the case of usual BCS systems. It is seen from the phase diagram obtained that in the high bipolaro-nic concentration region the system may exhibit a transition from the ferromagnetic to the mixed state on cooling, while in the low concentration region only the transition from the normal to the mixed state is possible.
1987, 36 (2): 165-171. doi: 10.7498/aps.36.165
The results of photolumenescence measurements of modulation doped GaAs/N-AlGaAs 2DEG at 4.2 K are reported. They show that the photolumenescence method can be used as a diagnostic means for determing the quality of 2DEG materials. The features of the spectra have some correlation with electronic properties of 2DEG and provide some possibilities for improving MBE technology.
THE LOCALIZATION AND CORRELATION EFFECT OF THE POTENTIAL FOR STRUCTURAL MODELLING OF BINARY AMORPHOUS ALLOY
1987, 36 (2): 172-182. doi: 10.7498/aps.36.172
The primary DRPHS configuration are relaxed with Lenard-Jones and Morse potential respectively for Co81P19 and Ni64B36 amorphous alloys. Two displacement fraction f=0.005 and f=1 are considered in the case of Ni64B36. Total energy, reduced partial distribution function and angular distribution function are obtained from the calculated data. Effect of localization and correlation of potential function on chemical short range order in binary amorphous alloys are discussed.
LIGHT ABSORPTION AND SCATTERING OF SMALL COLLOIDAL PARTICLES IN METALLIC COLLOIDAL PARTICLES-SEMICONDUCTOR THIN FILMS
1987, 36 (2): 183-190. doi: 10.7498/aps.36.183
Metallic colloidal particles- semiconductor thin films show special electrical, optical and photoelectric properties. The formulas for light absorption coefficient and scattering coefficient of small colloidal particles dispersed in semiconductor thin film are given in this paper. The colloidal particles may be spheroids, prolate spheroids or oblate spheroids. As an example, the effects of sizes and shapes of Ag colloidal particcles in Ag-Cs2O semiconductor thin films on light absorption and scattering are discussed. The calculated curves for relative absorption coefficient and scattering coefficient vs. wavelength λ are also presented.
1987, 36 (2): 191-198. doi: 10.7498/aps.36.191
In this paper, an improved and simple self-consistent effective-medium theory is developed. The effect of dispersed second phase particle on the ionic conduction of ionic conductors is discussed by the theory. It is found that the theoretical result is consistent with experiments. The theory can perdict the effect of microscopic feature of the material on the macroscopic ionic conduction.
1987, 36 (2): 199-207. doi: 10.7498/aps.36.199
Starting from Vlasov-Doisson equations, the coupled dynamics equations for slowly varying electron distribution function δFe, slowly varying field Es and fast varying field E are derived and the system of above equations is analytically solved. Thus, the interactions of the particles distribution functions with solitons are revealed. Furthermore, the collapse motions of δFe Es. E for higher dimensions and their many cavitons behavior are discussed.
INFLUENCE OF DIMENSION OF THE STEPPED HORNS WITH PIEZOELECTRIC TRANSDUCER ON THE PERFORMANCE OF THE VIBRATORS
1987, 36 (2): 208-216. doi: 10.7498/aps.36.208
In this paper, we discuss two types of vibrators, that connected by a single screw and that by a strain shell, respectively. The thick-end lengths of stepped horns are varied to find out their influence on the thin-end length, the gain of displacement amplitude, and the variation of displacement amplitude at the thin end. Optimized thick-end length are then selected out. For the vibrator connected by strain shell, the displacement amplitude of the thin end and the relationships among resonant frequencies and diameter of both the thick end and the thin end are determined. The relation between the thin-end length and resonant frequencies is also studied. The method for designing improved vibrators is given.
1987, 36 (2): 217-223. doi: 10.7498/aps.36.217
In this paper, an optimal iteration procedure, the projection-iteration method, is developed to solve the Cauchy problems of the flux function equation. This method exhibits higher convergent speed and is suitable for calculating the plasma configurations with divertors. Several important plasma configurations have been calculated. The numerical solutions are found to be in good agreement with the analytical solutions.
1987, 36 (2): 224-229. doi: 10.7498/aps.36.224
In this paper, we extend our previous work and calculate the field structure and the conversion efficiency of the higher order harmonics emission. In calculation, the effect of density profile steepening in the vicinity of the critical density has been taken into account by assuming a bilinear density profile. The analytical results obtained can give a reasonable explanation to the physical phenomena observed in CO2-laser experiments.
1987, 36 (2): 230-236. doi: 10.7498/aps.36.230
The downshift of lower velocity limit of resonant electrons in Landau damping due to the trapping of electrons in the potential barrier formed by the large-amplitude electrostatic waves is considered. By means of the ray-tracing method, the energy deposition of LHW on its trajectory in tokamks is computed. Considering the balance between the energy deposition and the Joule heating effect of the LHW driven current, the profile of LHW driven current in tokamaks has been obtained. The calculated results about PLT and JFT-2 are in agreement with the experimental results. For HL-1 device the computed results is also optimistic.
The problems of pseudo-symmetry are often appeared in the crystal structure. This paper discusses some possible kinds of pseudo-symmetry in molecule and between molecules. The unknown polypeptide crystal ctructure (M. W. =1111.4) have been solved success fully by using the pseudo-symmetry idea.
1987, 36 (2): 243-247. doi: 10.7498/aps.36.243
By using the point canonical transformation in path integral method, we obtained the exact wave functions of one dimensional Morse oscillator.
1987, 36 (2): 248-253. doi: 10.7498/aps.36.248
Measurements have been made on the electrical resistance of the metallic glasses Fe100-xBx (12≤x≤24) as a function of hydrostatic pressure in the range 0-8 kbar at room temperature. In all of the samples, the pressure coefficient of resistance aF( = d'ln R/dP) are negative This resistance-pressure behavior are discussed in cerms of the generalized Ziman theory.
We studied the phase transition of mordenite at high temperature by using the property of sorption of water, and by X-ray diffraction and differential thermal analysis. An anomalous phase transition to non-crystalline material had been found. The properties and formation of this phase transition had been studied and discussed.
V-V ENERGY TRANSFER IN DISSOCIATION PROCESS OF FREON 113 MOLECULES IN MULTIFREQUENCY INTENSE IR LASER FIELDS
1987, 36 (2): 259-263. doi: 10.7498/aps.36.259
Freon 113 molecules are superexited in multifrequency intense IR laser fields composed of 9P(24), 9P(22), 9P(20), 9P(18) lines of TEA CO2 laser, reaching very high exited states. It can be seen from the decomposition curve that a "siphonage effect" exists obviously in the V-V energy transfer between CF2C1·CFC12 and CF3·CCl3 molecules. From the main products C2F6, C2Cl6, C2F4 and C2F2C12, it is shown that the C-C bonds having higher energy in CF2Cl·CFCl2 and CF3·CCl3 were mostly broken, but only a few C-Cl bands having lowest energy ruptured. We propose a dissociation mechanism of Freon 113 molecule in multifrequency intense IR fields, and indicate that intramolecular V-V energy transfer is not randomized.
1987, 36 (2): 264-269. doi: 10.7498/aps.36.264
The variations of glass refletance or front reflectance Rf, vacuum reflectance Rv and tran-smittance T of well activated cesium oxide thin films with Ag addition were measured within the visible and infrared range. Rv increases as the amount of Ag increases, but Rf decreases at first, then increases. Optical absorptions of the thin film and silver particles increase as the amount of Ag increases, and its photoemission increases at first, and then decreases. A model with inhomogeneous distribution of silver particles is proposed.
1987, 36 (2): 270-274. doi: 10.7498/aps.36.270
Under UHV condition, the C-O stretching mode properties of diacetate cellulous (C2H8O3-(COOCH3)2) adsorbed on polycrystalline Ag surface were studied by using PAS. The peakpo-sitions, and the peak shifts and FWHM's, of the vibrational mode at different adsorbate coverages and different temperatures were demonstrated. Some features of adsorption of macromolecules on metal are discussed. The results also show that our facilities has the satisfactory sentivities for surface submonolayer detection.