Table of Content

20 September 1995, Volume 31 Issue 5

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Central Limit Theorem for Sums of Order Statistics

YANG Jingping

1995, 31(5):  527-537. 

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Let {X, X_i, i≥1} be i.i.d. random variables with non-degenerate d.f.F, and |X⁽¹⁾_n|≥|X⁽²⁾_n|≥...≥|X⁽ⁿ⁾_n| be the order statistics of |X₁|, |X₂|,...，|X_n|. For r_n→+∞，and r_n/n→0 as n→+∞, write ^(r_n)S_n=∑ⁿ_i=rn+1X⁽ⁱ⁾_n. This article gets the sufficient and necessary condition for ^(r_n)S_n convcrgcs to normal in distribution.

Continuation Method for Periodic Solution after Hopf Bifurcation

BAO Yangang,WU Jike

1995, 31(5):  538-541. 

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In this article Various kinds of methods about the solution of nonlinear system dx/dt＝F(x, λ) after the Hopf Bifurcation are discussed. We improve the method metioned in reference [2] and give the numerical solution of the van der Pol equations.

Initial-Mixed Boundary Value Problems for Nonlinear Parabolic Complex Equations of Second Order with Measurable Coefficients

WEN Guochun

1995, 31(5):  511-519. 

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This paper deals with the initial-mixed boundary value problem for nonlinear parabolic equations of second order with measurable coefficients in a multiply connected domain. Firstly, we give a priori estimates of solutions for the above initial-boundary value problem with some conditions, afterwards by using the above estimates of solutions and the compactness principle of solutions, the existence of solutions for the above problem is proved. Here the condition (1.4) is weaker than the corresponding condition in [1] and [4], i.e. the constant 4/3 in [1] and [4] is replaced by 3/2 in (1.4).

Primitive Permutation Groups with a Solvable Subconstituent of Degree 5

WANG Jie

1995, 31(5):  520-526. 

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In this paper we complete the classification of all primitive permutation groups which have a solvable subconstituent of degree 5.

A model for the Gathering of Particles in the Artificial Thrombus Machine

SUN Keli,WEN Gongbi

1995, 31(5):  542-551. 

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In the artificial thrombus machines such as Chandler loop, the thrombus is always formed at the frontal meniscus. This Phenomenon is amazing and puzzling for many years. Although people have known well about the fluid field in artificial thrombus machines, the reason why thrombus always forms at the specific position is still not clear. To study the mechanism of this phenomenon, we established a new model in which we consider the blood as the mixture of plasma and blood cells. The plasma is Newtonion and the cells are simulated by particles. For the existance of the tube wall, the particle will not always move with the liquid particle, but a little slower than the fluid, and more importantly, the fluid and the tube wall will produce a lift force which causes the particle to keep away from the walls. We assumes that the density of particles is low so that we can neglect the effects of the particles while calculating the fluid field. From the dynamic equations of the particle involving the lift force, we computed the motion of the particles. The results show that no matter where the particle sets off, it will tend to a stationary position near the fronter meniscus, this indicates that the lift force is oneof the main reason to cause the gathering of blood cells at the fronter meniscus of the artificial thrombus machine. Since the gathering of blood cells is a necessary event to form the thrombus, the lift force is very important to the thrombus formation in the machine, and it might be the working theory of the machines. This model are also applied for studying the effects of several factors, including the Reynolds number, the viscosity of liquid, and the size of the particles, on the gathering of blood cells and thrombus formation.

On the Matrices in the Stroh Formalism of Anisotropic Elasticity

WANG Wei

1995, 31(5):  552-555. 

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In this paper, we derive the six-dimensional Stroh formalism of the two-dimensional anisotropic elasticity with a direct way, and point out the structure of the matrices N_~i.

The Approximability of NP Optimization Problems

HUANG Xiong

1995, 31(5):  556-562. 

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The approximability of NP optimization problems is investigated in this paper. We classify the problems according to their approximability and prove that these classes are different (under the hypothesis P≠NP). In addition, we define a reduction which preserves the approximation ratio among the problems, and find complete problems under this reduction for every class.

Single Layer Chiral Plate Microwave Absorber

YIN Guangjun,ZHAO Liang,LIAO Shaobin,XIONG Keming

1995, 31(5):  563-570. 

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The paper presents the study of a single layer of chiral plate microwave absorber. The dependence of the microwave reflectance on the frequency for a single layer of the chiral plate microwave absorber is reported. The results indicate that the chiral microwave absorber gets a good performance. It means that the chiral material is a good microwave absorbing material. In addition, the phenomenon of the polarization plane rotation is observed as the electromagnetic wave passes through the chiral sample.

Giant Faraday Rotation in Diluted Magnetic Semiconductors Cd_1-xMn_xTe and Cd_1-xFe_xTe

WANG Rongming,WANG Xuezhong,CHEN Chenjia

1995, 31(5):  571-579. 

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Giant Faraday rotation as a function of photon energy andcomposition for Cd_1-xMn_xTe and Cd_1-xFe_xTe in temperature range 70K to 300K has been measured by using extinction, alternating magnetic field and magneto-optical modulation methods. Faraday rotation angles are negative and a single-oscillator model fit the data very well for Cd_1-xMn_xTe with relatively high compositions (x ≥0.1). It is shown that Cd_1-xFe_xTe crystals exhibit the same order giant Faraday rotation cha-racteristic as Cd_1-xMn_xTe. With relatively low composition x, Faraday rotation angles vary from positive to negative when photon energy closeto the band gap edge, a multioscillator model has been successfully usedto explain the data. Alternating magnetic field method is found to be the best one in this region, however, magneto-optical modulation methodtakes advantages of its high accurate for thin samples or under low magnetic field.

Experimental Study on Remote Sensing of Atmospheric Water Vapour Content and Liouid Water Content

HU Chengda,ZHU Yuanjing,DU Jinlin,ZHAO Bolin

1995, 31(5):  614-620. 

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The atmosphere is known as a source of heat noise in microwave bands. By means of ground-based reception of atmospheric emission cons-tituted mainly by oxygen, water vapour, cloud and rain, we could get the atmospheric temperature profile, humidity and the parameters of cloud and rain. By using atmospheric noise reception of 1.35cm water vapour absorptionband and 8mm window band, we could obtain the atmospheric total water vapourcontent and liquid water content of cloud. We have constructed a dual channelmicrowave radiometer and conducted observation experiments in Hebei and Shanxi provinces. In this paper the calibration of the radiometer output datais discussed in detail. It can be used in the experimental research of the cloud-radiation characters and making use of natural water resources in the sky.

Experimental Study of Spectra in New Diluted Magnetic Semiconductor Zn_1-xCo_xS

WANG Xuezhong,CHEN Chenjia,LIU Guobin,W Giriat

1995, 31(5):  580-585. 

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Absorption and Magnetic Circular Dichroism(MCD) spectra have been measured in a new diluted magnetic semiconductor Zn_1-xCo_xS(with x=0.001, 0.01, 0.03, 0.048, 0.053 and 0.063) at temperature 73K to300K in visible and near infrared region respectively for the first time. A series of absorption and MCD spectra have been observed. Both of the spectra are in good agreement and the peaks are independent on the composition of sample and corresponding to the transitions between the different energy levels of Co²⁺ ion in a crystal field of T_d symmetry.

Spectra of the New Type Diluted Magnetic Semiconductors Zn_1-xCo_xSe and Zn_1-xCo_xS

CHEN Chenjia,WANG Xuezhong,LIU Guobin

1995, 31(5):  586-590. 

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Spectra of the new type diluted magnetic semiconductors Zn_1-xCo_xSe and Zn_1-xCo_xS related to transitions between the dif-ferent energy level of Co²⁺ ions for states of d⁷ configuration have been calculated by crystal field theory. The comparison of calculated and observed spectra of Co²⁺ ions have been given. Bothare in good agreement in the low energy level part. Crystal field D_q, Racah B, C and spin-orbit coupling λ parameters have been obtained and observed spectra of Co²⁺in Zn_1-xCo_xSe and Zn_1-xCo_xS have been designeted, respectively.

Design of the Control Module for the TFT AMLCD Monitor of Microcomputer

GUAN Xudong,LIU Xiaoyan,ZHANG Rongtian,ZHAI Xiayun,HAN Ruqi

1995, 31(5):  591-598. 

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Based upon the display standards of IBM-PC CGA and the principle of thin film transistor (TFT) active matrix (AM) liquid crystal display (LCD), a control module including the circuits of LCD controller (LCDC) and encoding circuit et.al. are designed, which operats as CGA model and is able to replace CRT monitor in personal computer.

Theoretical Analysis of Erbium-Doped Fluoride Fiber Amplifier

GU Jinxing,XU Chenghe

1995, 31(5):  599-608. 

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A theoretical analysis of erbium-doped fluoride fiber amplifiers(EDFFAs) is presented in this paper. By using this theoretical modelling its gain, noise and saturated output power performance have been calculated numerically, and compared with erbium-doped silica fiber amplifier(EDSFA).

The Equatorial Counter Electrojet and the Electrostatic Potential Across the Polar Cap

SHEN Changshou,ZI Minyun

1995, 31(5):  609-613. 

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Up to now, the equatorial counter electrojet (CEJ) is considered as an unusual phenomenon, which is caused by a special combina-tion of tidal modes, or by a local vertical wind shear or a gravity-wave at ionospheric height above the equator. This paper shows, however, under an average state given by the empirical models of IRI-90, MSIS-90 and HWM-90 for middle-and low-latitude ionospheres on geomagneticallyquiet days, the CEJ occurs frequently. On the other hand, the CEJ disappears under the effect of the electrostatic potentialacross the polar cap (the dawn-dusk electic field) driven by the magnetosphere-ionos-phere coupling.

The Anomaly of the Isothermal Remanent Magnetization of the
Heated Siderite and the Reverse Magnetization

LIU Huangfeng,ZHOU Yaoxiu,DONG Jinming,QIN Shan

1995, 31(5):  621-630. 

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All the shapes of the isothermal remanent magnetization(IRM) curves of the samples, which were derived from the heat-treated sideriteand sand siderite samples within a certain temperature range, can be divided into three types, each corresponding one essamble of the initial states of remanent magnetization. According to the existence of segmentswith minus slope for theanomalous IRM curves, a reverse magnetic phase is suggested to have occurred during the heat treatment before and the anomalous behavior of IRM curve is tentatively explained with the coupling between a normal magnetic phase and a reverse magnetic phase. Thiskind of revere remanent magnetization were obtained by magnetizing at the room temperature and no any thermal and chemical processes participate in the magnetizing. Therefore, it differs, in essence, from the thermal and chemical reverse remanent magnetization which have been observed before.

Application of Cathodoluminescence to Mineralization and Lithogenesis Studying

LAI Yong

1995, 31(5):  631-638. 

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The cathodoluminescence is a crystal luminescence caused by that the streams of electrons from cathode are directed onto the crystal surface.Usually, the trace elements in crystal are the activator that influnce the formation of luminescence center. The composition ofore-bearing fluid has been changing during the growthing of crystal. So the same minerals which have different generations or the growth zones of a mineral crystal have different luminescence under the cathodoluminescence microscope. It is helpful to distinguish the different generation minerals and a crystal microstrctural marakers in which the fluid inclusions can be finded. The sample which come from Guangtoushanaklali granite ,Wendeng gold deposit and Shuikoushan silicalite are studied under the cathodoluminescence microscope. In this background, detail P-T-V-X properties of fluid are determined from the further studying the fluid inclusions.