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1992年, 第1卷, 第1期　刊出日期：1992-01-20    下一期

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THE INHOMOGENEOUS PERIODIC STATES IN A COUPLED MAP LATTICE 丁鄂江, 吕燕南 1992 (1):  3-10.  doi: 10.1088/1004-423X/1/1/001 摘要 ( 1228 )   PDF(156KB) ( 605 )   Numerical method is used to study the inhomogeneous periodic states in a coupled map lattice, and some scaling relations are obtained. The statistical language is proven to be suitable to describe the inhomogeneous periodic states because of its sensitive dependence on the initial conditions. 相关文章 | 计量指标

ATOMIC AND MOLECULAR PHYSICS

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NON-BOLTZMANN ENERGY LEVEL DISTRIBUTIONS OF ARGON ATOMS IN THE INDUCTIVELY COUPLED ARGON PLASMA 黄矛, 刘克玲 1992 (1):  11-18.  doi: 10.1088/1004-423X/1/1/002 摘要 ( 1128 )   PDF(221KB) ( 546 )   Based on collisional and radiative processes occurring in the inductively coupled plasma, non-Boltzmann energy level distributions of argon atoms are calculated under various conditions, by using ideal gas law and solving rate equations. 相关文章 | 计量指标

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STUDY OF HIGH-LYING EXCITED STATES OF RARE-EARTH ELEMENT Dy BY LASER RESONANCE IONIZATION SPECTROSCOPY 周海军, 许祥源, 黄雯, 李良权, 陈瓞延 1992 (1):  19-26.  doi: 10.1088/1004-423X/1/1/003 摘要 ( 1273 )   PDF(200KB) ( 550 )   This paper describes the investigation of high-excited states of Dy. which includes the measurement of high Rydberg states and autoionizing states, by means of laser resonance ionization spectroscopy (LRIS). Two high Rydberg series (n>40), 4f10(5I8) 6sns and 4f10(5I8) 6snd, have been obtained by exciting the state of 4f10(5I8) 6s6p (3P02) 5I08 using two-step laser excitation-electric field ionization method. With the data obtained, we determined the first ionization potential of Dy. It is 47901.7±0.6 cm-1, that is. about one order more accurate than the results given in the literature. Using the same technique, we found 97 autoionizing states by exciting the state of 4f95d6s(7H07). 相关文章 | 计量指标

CLASSICAL AREAS OF PHENOMENOLOGY

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ANALYSIS OF THE GENERAL EFFECTS IN DOUBLE-GRATING DIFFRACTION-INTERFERENCE SYSTEM 詹黎, 屠锦洪, 郭嘉荣 1992 (1):  27-44.  doi: 10.1088/1004-423X/1/1/004 摘要 ( 1156 )   PDF(439KB) ( 1151 )   Based on the ambiguity function, the optical phenomena of the double-gearing diffraction-interference system are analysed with partially coherent illumination. Different patterns are observed on the observation plane when the optical elements are placed in their proper positions. Detailed discussions on the two extremes of coherence are given. Conclusions could be obtained about the Lau effect, the generalized Lau effect, the incoherent grating-lens imaging, the Talbot effect, the joint-Talbot effect and the generalized joint-Talbot effect. Some special cases are also verified by experiments. 相关文章 | 计量指标

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FIRST-PRINCIPLE SELF-CONSISTENT PSEUDOPOTENTIAL CALCULATION OF THE ELECTRONIC STRUCTURES OF SHORT-PERIOD (GaAs)m(AlAs)n SUPERLATT1CES 范卫军, 顾宗权, 夏建白, 李国华 1992 (1):  45-50.  doi: 10.1088/1004-423X/1/1/005 摘要 ( 1386 )   PDF(172KB) ( 466 )   With the local density approximation, the band structares of the short-period (GaAs)1(AlAs)1 and (GaAs)2(AlAs)1 superlattices are calculated by using the first-principle self-consistent pseudopotential method. The results show that the (GaAs)1(AlAs)1 superlattice is an indirect semiconductor, and the lowest conduction band state is at point R in the Brillouin zone; the (GaAs)2(AlAs)1 superlattice is a direct semiconductor and the lowest conduction band state is at point Γ. The squared matrix elements of transition are calculated. The pressure coefficients of energy gaps of the (GaAs)1(AlAs)1 and (GaAs)2(AlAs)1 superlattices are calculated and compared with those obtained by hydrostatic pressure experiments. 相关文章 | 计量指标

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FAR-INFRARED AND INFRARED REFLECTIONS OF Tl2Ba2Ca2Cu3O10 FILM 叶红娟, 胡灿明, 黄叶肖, 陆晓峰, 王志涛, 曾文生, 张光寅, 阎少林 1992 (1):  51-56.  doi: 10.1088/1004-423X/1/1/006 摘要 ( 1420 )   PDF(170KB) ( 470 )   The far-infrared and infrared reflection spectra of Tl2Ba2Ca2Cu3O10 superconducting film are reported in this paper. It is found there are three sharp reflection edges in both the superconducting and normal states, their positions being near ≈ 150, ≈ 350 and ≈600 cm-1. We attribute these reflection spectra to the Drude free carriers and a wide mid-infrared absorption band. When the incident angle increases from 7° to 30°, some additional stractures appear in the refiection spectra, which are the A2u phonon modes vibrating along c-axis. 相关文章 | 计量指标

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MAGNETIC PROPERTIES AND CRYSTALLIZATION OF THE RAPIDLY QUENCHED (Fe1-xNdx) 81.5B18.5 ALLOYS 沈保根, 杨林原, 郭慧群 1992 (1):  57-62.  doi: 10.1088/1004-423X/1/1/007 摘要 ( 1205 )   PDF(186KB) ( 468 )   Magnetic properties and crystallization behaviors of amorphous (Fe1-xNdx) 81.5B18.5 alloys were studied. The crystallization temperature is found to rise at first and then drop monotonically with x, having a maximum value of 976K at x=0.11 (9at% Nd). The (Fe1-xNdx) 81.5B18.5 alloys prepared at a quenching rate of vs = 6.6m /s are amorphous, and exhibit good glass formability. Both the coercive field Hc and energy product (BH)max depend strongly on Nd concentration. Amorphous (Fe1-xNdx) 81.5B18.5 alloys with higher Nd concentration have a high coercive field at low temperature, due to the large random uniaxial anisotropy of Nd. The room-temperature Hc and (BH)max obtained on optimal annealing con-ditions show two maxima as a function of Nd concentration x. The highest room-temperature coercive field Hc =22 kOe within the Nd concentrations around x=0.368 and the maximum energy product(RH)max= 13.3 MG·Oe at x =0.055 are observed. The hard magnetic properties of these crystallized samples are related to the presence of the bard magnetic Nd2Fe14B phase. 相关文章 | 计量指标

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DYNAMICS OF CARRIER CAPTURE IN AlGaAs/GaAs MULTIPLE QUANTUM WELLS 林位株, 彭文基, 丘志仁, 周学聪, 莫党 1992 (1):  63-68.  doi: 10.1088/1004-423X/1/1/008 摘要 ( 1196 )   PDF(187KB) ( 470 )   Dynamics of carrier relaxation and capture in AlGaAs/GaAs multiple quantum wells (MQW) at 80 K is studied using picosecond luminescence and femtosecond absorption saturation measurements. Carriers generated in the wells and in the barriers scatter initially out of the excited states to a quasi-equilibrium state in 35 and 400 femtoseconds, respectively, before they are captured into the bound states of the quantum wells. Carrier capture occurs during carrier cooling and recombination. A carrier capture time of 25 ps has been deduced from time-resolved luminescence. 相关文章 | 计量指标