Table of Content

31 December 1994, Volume 12 Issue 4

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Articles

A NEW KIND OF DISK ARRAY-RAID7

LUO XINGUO, ZHANG JIANGLING

1994, 12(4):  315-319. 

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The disk array techniqne is an efficient way to break the I/0 bottleneck of the computer system,and is widely studied and developed recently in the world.In order to increase the reliability of the disk array, this paper proposes a new kind of disk array-RAID7 (Redundant Array of Inexpensive Disks level seve),in which the data store unit of the array is coded using the extended Hamming code.It gives high data availability and high system reliability.

AN ALGORITHM OF LINK PATH FOR SUPER-CUBE MULTISTAGE NETWORK

LONG WEI

1994, 12(4):  320-324. 

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In this paper,the super-cube network is defined as a net-array with k stages and r layers, and the relevant terms are scientifically defined. From the point of view of linking the dynamic paths,the algorithms about the net-node value, the net-layer value and the linking statements are studied. By using these algorithms,we can completely determine the dynamic linkage paths about a super-cube network.At the end of the paper,we give an example about the algorithms.

PARAMETRIC TYPE DYNAMIC TYPE CHECKING

MEI HOHG, SUN YONGQIANG

1994, 12(4):  325-332. 

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The data type is an important concept in the programming languages design.Based on the argument of Milner's polymorphic type system,this paper presents a parametric type system which treats types as first-class objects,and provides dynamic type checking for this system.

THE BEST APPROXIMATION OF DISCRETE RANDOM OBSERVATIONS

LIU YONGCAI, LIN GANG

1994, 12(4):  333-339. 

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A number of scientific experiments, engineering tests and expert systems involve a class of problems:how can the Boolean functions be identified from finite random observations,so that the Boolean functions can best represent the relationships in a set of observations? Some approaches to this problems are given in this paper.

THE FMR OF DOUBLE-LAYERED (BIAL)YIG FILM GROWN BY COBTINUAL LPE

ZHANG YING, OUYANG JIA, SU JUN, ZHOU SHICHANG, HE HUAHUI

1994, 12(4):  340-344. 

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The growth and lattice mismatch of the double-layered (BiAl) YIG film are described in this paper, The FM R spectra of the film are measured with the static magnetic field applied at various angles to the film normal.Peculiarities are revealed in the dependences of the FMR fields,intensities and linewidths on the angle, which are different from those of the single-layered film. The magnetic coupling between two layers is used to explain the nonuniform widening of the FMR linewidth of the double-layered film and the new phenomena in the FMR spectrum.The interlayer magnetic coupling parameters are calculated to be different at different angles.

THE QUANTUM FLUCTUATIONS OF THERMAL TRANSPORT COEFFICIENT

YANG XINE, XU XIANGTONG, LIN JIATIH

1994, 12(4):  345-348. 

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The qnantum interference effects on thermoelectric coefficients in the small size sample are discussed in this paper. Assuming that the electron-electron interactions and the inelastic scatterings are weak and using a corrected Wiedemann-Franz relation, we could obtain the function dependance of the relative thermal conductivity on the relative electric conductivity. The result shows that the thermal conductivity exhibits periodic fluctuation corresponding to the electric conductivity flnctuation, but that the amplitude is lower.

STUDY ON ENHANCED TREEING PROPERTY FOR POLYETHYLENE BY EFFECTIVE VOLTAGE STABILIZERS

GAO LIANGYU, LIU YUE, TU DEMIN, HUANG GENLONG

1994, 12(4):  349-354. 

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Two kinds of effective voltage statbilizers (ferrocene derivatives) have been systhesized by the authors. The mechanism of treeing inhibition by ferrocene derivatives is discussed through the relation of the conductivity and electric field and comparison of their ionization potentials.

A STUDY ON THE RELATIONSHIP BETWEEN THE CHANGE OF PERFORMANCE AND CRYSTALLINITY OF POLYTETRAF LUOROETHYLENE BY MEANS OF THE POSITRON ANNIHILATION LIFETIME SPECTROSCOPY

SHI ZIKANG

1994, 12(4):  355-360. 

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In this paper, the positron annihilation lifetime spectroscopy parameters are used to calculate the crystallinity of PTFE for the first time.The mechanisms of influence of annealing and a low dose of ⁶⁰Co-irradiation on the crystallinity are studied.Itis brought to light that the secondary long composition of the positron annihilation lifetime spectrum is the transition state to the captured positron e⁺ or positronium O-P.In this state there exists no positronium P-PS captured or annihilated.

INVERSION FOR LAMEE'S PARAMETERS λ、μ AND DISSIPATIVE FACTOR γ IN LAYERED EARTH MODEL

ZHENG JIAMAO, WANG YUANMING, WEI YU, LI YOUMING

1994, 12(4):  361-367. 

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The in version method for Lame's parameters λ、μ and dissipative factor γ in the layered earth model is set up by means of the 2-D one order dissipative elastic wave equation in the vector form. Through transformation and decomposition,the inverse problem for λ、μ、γ in the 2-D one order dissipative elastic wave equation in the vector form is changed into the inverse problem for λ、μ、γ in the 1-D one order partial differential system with a free boundary. It is proved the inverse problem is well-posed. So we know that Lame's parameters λ、μ and dissipative factor γ in the layered earth model can be uniquely determined from the particle velocity fields on the line in its surface at all times due to the transverse and longitudinal pulse plane waves simultaneously emitted at normal incidence.

A NEW METHOD OF CONSTRUCTING THE CORRELATION-IMMUNITY FUNCTIONS

FENG DENGGUO, XIAO GUOZHEN

1994, 12(4):  368-370. 

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In this paper,we present a method of constructing some second -order correlation-immunity functions with the Hadamard array.

SOLUTION OF BOUNDARY-VALUE PROBLEMS IN NONLINEAR VISCOELASTICITY BY SUCCESSIVE APPROXIMATIONS

ZUO JINPING

1994, 12(4):  371-378. 

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Starting from the basic equations of the nonlinear theory of viscoelasticity,we deduce the successive boundary-value problems by the method of successive approximations. As a concrete example, we find the first-and second-order solutions for a thick-walled cylinder. On the inner surface of the cylinder, the displacement is prescribed, and on the outer surface, the traction is null. We thus obtain the formula in the second approximation for the stress field in the cylinder, Finally,we compare numerically the linear solution with the nonlinear one.

PHOTOELECTREC IMAGING OF SEMICONDUCTOR P-N JUNCTIONS

GUO LIANG, ZHANG ZHONGNING, ZHANG SHUYI, XIE YUN

1994, 12(4):  379-386. 

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The results of the photovoltaic detection of P-N junctions with different bias voltages under the illumination of periodically modulated laser are presented in experiment and theory. The static and dynamic photovoltaic images of semiconductor P-N junction devices are obtained by photoelectric microscopy.The studies of the phybsical mechanism of the photovoltaic detection of semicon-ductor P-N junctions provide effectively the analytical foundations of the static and dynamic photovoltaic images of integrated circuits.

OPTICAL WAVEGUIDE HAVING THE FUNCTIONS OF WAVELENGTH DIVISION MULTIPLEXER AND OPTICAL SWITCH

LIN ZHIYUAN, XU YI

1994, 12(4):  387-394. 

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In this paper,a new type of optical waveguide having the functions of the wavelength division multiplexer and optical switch is presented. The characteristics of this device are analyzed and calculated numerically by employing the beam propagation method (BPM).The results of preliminary experiments indicate that this device has the good performance of the wavelength division multiplexer and the optical switch.

EFFECT OF S-GaAs SURFACE BONDS ON GaAs ELECTRONIC PROPERTY

ZHANG GUIQIANG, CAI SONGYI, ZHU YONQIANG, CAO YONGMING

1994, 12(4):  395-400. 

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The electronic properties of GaAa are dramatically improved in samples treated with aqueous solntion of sodinm sulfide nonahydrate (Na₂S·9H₂O).Experimental results show that the characteristic curves of capacitance-voltage (C-V) vary shape for the Na₂S·9H₂O treated samples, and that its potential barrier capacitance is higher than that of the untreated sample. The X-ray phtoelectron spectroscopy (XPS) reveals that the oxygen on the GaAs surface treated with Na₂S·9H₂O is remarkably removed, and that the peak of the binding energy of As varies from the background peak 1321.00 eV to 1321.47 eV, a shift of 0.47 ey. The sulfur depth profile on the GaAs surface is determined by the secondary ion masss pectroscopy (SIMS). New S-As bonds and compound of arsenic sulfide are formed on the GaAs surface, making the "pinned" Fermi level improved. The surface state density and surface recombination center on the sodium salfide treatment sample have been greatly reduced, which is favorable for controlling the charge in GaAs.

ION IMPLANTATlON THROUGH CoSi₂/Si AND SELF-ALIGNED SILICIDED MOS DEVICE TECHNOLOGY

LIU PING, LI BINGZONG, HUANG WEINING, JIANG GUOBAO, GU ZHIGUANG

1994, 12(4):  401-408. 

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A new technology for the fabrication of self-aligned silicided MOS transistors was investigated. Self-aligned highly conductive CoSi₂ films were formed on the areas of the source/drain and gate electrode by solid state reaction of Co/Si.Dopants were implanted through CoSi₂/Si. The dopant and damage depth profiles were calculated by the eomputer program TRIM. The ion energy was properly selected to make the peak of dopant concentration locate at the interface of CoSi₂/Si. By a rapid thermal annealing after implantation, high-performance enhanced and depletion MOS transistors were fabricated with high carrier concentrations at the interface of CoSi₂/Si. The redistribution of the implanted dopants in the structure of CoSi₂/Si during different thermal processes was also studied. The results show that phosphorous has the tendency of diffusing into Si substrate, but boron prefers to stay in CoSi₂.

A DEMODULATION ALGORITHM FOR QPSK oF ALL DIGITAL RECEIVERS

LIU HONG, CHEN JINGXIN

1994, 12(4):  409-415. 

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In this paper, a new algorithm of digital signal processing for QPSK demodulation is proposed,This algorithm directly processes the phase of the received signal, thus realizing the demodulation of the QPSK。In contrast to other known methods it allows it allows free-running carrier oscillators. The analysis of the noise property of the algorithm is also presented. The computer simulation results indicate that the algorithm is a new method with a bright future for application.

RESEARCH ON INJECTION HEAT TRANSFER

LIU JIANMIN

1994, 12(4):  416-422. 

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According to the analysis by regression,the data management on measurement results of injection heat transfer was carried out, and the criterion equation was obtained. Its relative calculation error is about 0.5%, So it can be applied to engineering designing.

ADAPTIVE SAMPLING METHOD:A NEW SAMPLING METHOD FOR THE MEASUREMENT OF GEOMETRIC FORMS

FEI BIN, FAN YUJIAN, XU WENXIONG

1994, 12(4):  423-430. 

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A new sampling method called the adaptive sampling method for the measurement of geometric forms has been developed and conducted in this paper, Unlike the method generally used at present which accepts a fixed sampling interval determined premeditatedly, the new one determines an optimum sampling interval automatically according to the features of the measured profile in-process. By means of it,not only can any special or extreme point on a profile be sampled if need be, but also measured information can be selected by holding the useful data and deleting the useless data according the profile features and assessment criteria, The principle and applications of this new method are investigated. And practical experiments as well as simulant examples on the roundness measurement of a shaft in turning process are introduced in this paper, Our research and practical experiments show that the efficiency accuracy and reliability of measurement for geometric forms can be improved greatly by accepting the new adaptive sampling method, especially in manufacturing automation and in-process measurement.

THE STUDY OF INOCULATION MECHANISM OF CAST IRON

WANG CHUNSHENG, JAN MI, TIAN LI

1994, 12(4):  431-434. 

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In this paper,the thermodynamic theory of nucleation in a cone hole is analysed.On the basis of the calculation of the thermodynamic theory, a crackle inoculation mechanism of cast iron is Put forward. This inoculation mechanism can be used to explain the various phenomona of many experiments.