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1995年, 第4卷, 第12期　刊出日期：1995-12-20 上一期    下一期

ATOMIC AND MOLECULAR PHYSICS

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PHOTOIONIZATION IN AN INTENSE LASER FIELD 刘杰, 陈式刚, 鲍德海 1995 (12):  881-888.  doi: 10.1088/1004-423X/4/12/001 摘要 ( 1462 )   PDF(200KB) ( 523 )   In this paper classical approaches are used to study the detailed processes of photoion-ization in an intense laser field. The analytic expression of the ionization rate is derived. Finally, the results obtained are compared with existing theories such as Landau's tunnel theory and Keldysh-Faisal-Reiss theory. 相关文章 | 计量指标

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FREQUENCY-MODULATION OPTICAL-OPTICAL TRIPLE-RESONANCE OPTICAL HETERODYNE SPECTROSCOPY 江红杰, 丁良恩, 夏慧荣, 王祖庚 1995 (12):  889-898.  doi: 10.1088/1004-423X/4/12/002 摘要 ( 950 )   PDF(253KB) ( 347 )   We propose new frequency-modulation optical-optical triple-resonance (FM-OOTR) op-tical heterodyne spectroscopy, which can eliminate the Doppler-background in the recently developed optical-optical triple-resonance (OOTR) spectroscopy and provide improved reso-lution and sensitivity. Theoretical considerations and line shape calculations are presented. The potential applications of FM-OOTR technique to laser frequency stabilization with sig-nificant advantages can be expected. 相关文章 | 计量指标

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CHARGE STATES OF SPUTTERED ATOMS/IONS 潘立民, 王炎森, 黄发泱, 汤家镛, 杨富家 1995 (12):  899-905.  doi: 10.1088/1004-423X/4/12/003 摘要 ( 1394 )   PDF(170KB) ( 418 )   The charge states of sputtered cesium and oxygen ions/atoms from metal surfaces have been discussed with the time-dependent Newns-Anderson model. The final charge state distribution has been calculated as a function of work function of the surfaces. The calculated results fit the experimental data well. Besides, the dependence of the final charge states of the sputtered oxygen particles on the surface temperature is also predicted. 相关文章 | 计量指标

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PRESSURE DEPENDENCE OF ELECTRON DENSITY DISTRIBUTION IN GLOW DISCHARGE 郭小明, 周庭东, 白秀庭 1995 (12):  906-911.  doi: 10.1088/1004-423X/4/12/004 摘要 ( 1192 )   PDF(151KB) ( 653 )   Based on a glow discharge model of analytic form developed recently and by using the available data for the diffusion coefficients and mobilities of electrons and positive ions, the pressure effects on the spatial distribution of the electron density n have been systematically calculated and analyzed, The gas employed in the study was pure argon and the pressure range was from 0.1 to 1Torr. Theoretical results were found to be consistent with the experimental observations. 相关文章 | 计量指标

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NEUTRON-POWDER-DIFFRACTION STUDY OF ErFe11.35Nb0.65 AND ErFe11.35Nb0.65Ny 孙向东, 严启伟, 张泮霖, 胡伯平, 王开鹰, 王亦忠 1995 (12):  912-916.  doi: 10.1088/1004-423X/4/12/005 摘要 ( 1353 )   PDF(149KB) ( 341 )   ErFe11.35Nb0.65 AND ErFe11.35Nb0.65Ny have been synthesized and neutron-powder-diffraction experiments at room temperature performed. The ErFe11.35Nb0.65Ny nitride, obtained by gas-solid reaction, retains the ThMn12-type structure of its parent compound. The Nb atoms occupy 8i sites and the nitrogen atoms are located at 2b sites. The atomic magnetic moments of the Er ions are antiparallel to those of the Fe atoms. Upon nitrogenation, the lattice cell expands mainly along the a-axis and the atomic magnetic moments of Fe are enhanced. 相关文章 | 计量指标

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STUDIES ON THE NEXT-NEAREST NEIGHBOR HOPPING INTERACTIONS OF π-ELECTRONS IN QUASI-ONE-DIMENSIONAL ORGANIC FERROMAGNETIC MODEL 方忠, 刘祖黎, 姚凯伦, 李再光 1995 (12):  917-922.  doi: 10.1088/1004-423X/4/12/006 摘要 ( 1024 )   PDF(172KB) ( 420 )   Based on a theoretical model proposed for quasi-one-dimensional organic polymer fer-romagnets, the next-nearest neighbor hopping interactions of sr-electrons are considered. Allowing for full lattice relaxation, a set of self-consistent equations is established to study the system. The spin-density-wave (SDW) and the possible ferromagnetic ground state of the system are investigated in detail. It is found that the next-nearest neighbor hopping in-teractions will make the SDW stronger and consequently make the ferromagnetic state more stable as compared with the nonmagnetic reference state. 相关文章 | 计量指标

CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES

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THEORETICAL AND EXPERIMENTAL INVESTIGATION ON ANOMALOUS HALL EFFECT OF HETEROGENOUS SEMICONDUCTOR SAMPLES 姜伟, 鲁刚, 宋录武 1995 (12):  923-932.  doi: 10.1088/1004-423X/4/12/007 摘要 ( 1109 )   PDF(239KB) ( 361 )   Based on the theoretical results of inversion layers model and interpenetrating network model, we studied the anomalous Hall effect of heterogenous semiconductor samples, and obtained the following results: (1) the wider the sample energy gap, the higher the temper-ature at which anomalous Hall effect begins to appear; (2) the lower the sample resistivity, the higher the temperature at which anomalous Hall effect begins to appear, which is further verified in our experiment; (3) mobility is the main factor which determines what role p-n junction plays in sample Hall voltage; (4) for n-Ge sample with inversion layers structure, with the increase of p-type region, the Hall effect changes from normal n-type Hall effect to anomalous Hall effect of the single dip type, then to anomalous Hall effect of the second reversal type. 相关文章 | 计量指标