空间科学学报

1999 Vol. 19, No. 1

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SPECTRAL STUDY OF BE/X-RAY BINARY LSI+61°303

LIU Qingzhong, HANG Hengrong, ZHU Zhenxi

1999, 19(1): 1-6. doi: 10.11728/cjss1999.01.001

Abstract(1584) PDF 402KB(613)

Abstract:
New optical intermediate dispersion spectra of the periodic radio star LSI+61°303 are presented. The Her emission line shows a typical shell absorptionspectrum, which means that the primary of this Be/Xray binary may be a nearlyequator-on Be star. The Her emission line profile and its variation are analyzed,and some parameters such as the Ha Ed and V/Rpeak ratio change strongly nearthe radio maximum, and may exhibit periodic variability. Instead of having a widerminimum lasting for about half an orbital cycle as radio flux and Vmagnitude do,the Her EWshows a deep minimum at phase ～0.75. The accretion disk around theneutron star formed near its periastron passage is suggested to be responsible forthe change when it eclipses the primary and its envelope.

MULTI-SPECTRAL OBSERVATIONS OF A FLARE ON OCTOBER 27, 1992

QIU Jiong, XU Aoao, WANG Tongjiang

1999, 19(1): 7-14. doi: 10.11728/cjss1999.01.007

Abstract(2058) PDF 657KB(865)

Abstract:
In this paper, a IN/M1.1 flare is studied in Ho, soft X-ray and hard X-rayemissions. Both thermal and nonthermal emissions are found in this flare whichdemonstrate various tempo-spatial features. Through investigating the observationsfrom all available wavelengths, the thermal or nonthermal properties of the flare canbe determined, with respect to which, distinctively different types of Her line profilesin different flare regions can be explained.

ALFVEN SHOCK-LIKE STRVCTURE WITH A PARALLEL ELECTRIC FIELD──ACCELERATION MECHANISM OF AURORAL PARTICLE

SONG Liting, LU Xianhe, WANG Deyu

1999, 19(1): 15-21. doi: 10.11728/cjss1999.01.015

Abstract(2254) PDF 436KB(902)

Abstract:
As a result of dispersion and dissipation the kinetic Alfven wave nonlinearlyevolves into a shock-like structure. It carries a parallel electric field along the magnetic field, and offers a new mechanism for auroral particle acceleration. The wavemeasurement above the polar ionosphere by Freja satellite found a similar solitaryAlfven structure, which is comparable to the shock-like structure as predicted bythe theory.

HIGHER-ORDER STATISTICS AND IDENTIFICATION OF NON-LINEAR PROCESSES IN SPACE PLASMAS

ZHAO Zhengyu, XIE Shuguo, SHI Xianqing

1999, 19(1): 22-27. doi: 10.11728/cjss1999.01.022

Abstract(1781) PDF 393KB(710)

Abstract:
Using the higher-order statistical methods, the physical properties of certainsatallite data were described. The question addressed in this paper is the usefulness of higher-order statistics for identification of the wave-particles interaction inspace plasmas. The signals considered here are respectively ELFfrequency rangeelectrostatic turbulence and fluctuation in electron density measured on the low latitude satellite AUREOL-3 from the ARCAD-3 scientific experiment. The analysisshows that one can well identify the non-linear behaviour in the processes usingsuch method.

ION RING-BEAM INSTABILITY DRIVEN BY IONS WITH A PARTIAL SHELL DISTRIBUTION

CAO Jinbin, ZHOU Guocheng, WANG Xueyi, WU Chingshen

1999, 19(1): 28-33. doi: 10.11728/cjss1999.01.028

Abstract(2238) PDF 411KB(846)

Abstract:
In the interaction between ion ring-beam and waves, the ring-beam velocitydistribution of the ions will evolve into a partial shell velocity distribution. Thespread of pitch angle of this partial shell increases with time, the peak value ofgrowth rate spectrum of the right hand ion beam instability decreases in generaland shifts to the region of higher frequency and larger wave number. The peakvalue of growth rate spectrum of the left hand instability driven by ions with aninitial ring distribution decreases rapidly with the increase of the spread of the pitchangle of the partial shell and shifts to the region of lower frequency and longer wavenumber.

STORM-TIME JOULE HEATING OF AURORAL THERMOSPHERE AND IONIZATION DEPLETION IN THE F-REGION ──EISCAT RADAR OBSERVATION

MA Shuying, LIU Huixin, XU Jisheng

1999, 19(1): 34-41. doi: 10.11728/cjss1999.01.034

Abstract(1966) PDF 516KB(1644)

Abstract:
With the help of EISCAT radar data, auroral ionospheric electromagnetic parameters, such as convection electric field, conductivity tensor, and Joule heating rates etc. are calculated and analyzed for an intense magnetic storm (min.D_st<=-150nT) occurring in summer of a high solar activity year. An investigationis emphatically made on the relationship between the thermospheric Joule heatingin the E-region and frictional heating of ions in the F-region with the ionizationdepletion in the F-region. It is found that at the sector of eastward auroral electrojet in the afternoon, a maximum depletion of 70% in electron density occurs ataltitudes of 300-325 km, its occurrence lags just 5-10 minutes after the integatedJoule heating reaches to its mamximun of about 92 mW/m² in the E-region and ionfrictional heating in the F-region, to its maximum, too.

ON THE ATTENUATION OF THE VLF RADIO WAVES IN THE EARTH'S IONOSPHERE

LI Kai, PAN Weiyan

1999, 19(1): 42-46. doi: 10.11728/cjss1999.01.042

Abstract(1804) PDF 320KB(1419)

Abstract:
The attenuation of the VLFradio waves in the Earth's ionosphere is analyzedand computed. Using the Fourier Tansformation, one may obtain the formulation which indicates the attenuation changing with ionospheric collision frequenciesand the geo-magnetic orientations. Numerical results of the relations between theattenuation and the ionospheric collision frequencies under several geo-magneticorientations are given.

EFFECT OF VISCOUS DISSIPATION ON RESONANT INTERACTIONS AMONG GRAVITY WAVE PACKETS

Yi Fan

1999, 19(1): 47-53. doi: 10.11728/cjss1999.01.047

Abstract(1827) PDF 420KB(888)

Abstract:
By using a numerical method the effect of viscous dissipation on the resonantinteractions among gravity ware packets is studied. It is shown that the viscous dissipation not only decays the wave energy but also strongly changes the local energytransfer between wave packets. Thus the energy distribution of each wave packet isfurther altered. The viscous dissipation slows down the development of interactionprocess and impedes a portion of secondary waves with high wavenumber to interactwith the primany wave.At the altitudes of the thermosphere the dissipation processdominates over the interaction the evolution characteristics of resonant interactionbecome remarkbly different. Through interacting with small-scale secondary wavesa propagating gravity wave packet can heat the atmosphere more rapidly.

THE OBSERVATION AND THEORETICAL MODELING OF SODIUM DISTRIBUTION OVER WUHAN, CHINA

LI Hongjun, ZHENG Wengang, YANG Guotao, GONG Shunsheng

1999, 19(1): 54-60. doi: 10.11728/cjss1999.01.054

Abstract(1875) PDF 455KB(1192)

Abstract:
The WIPM sodium resonance lidar and the inversion method of observationdata are introduced, the modeling calculation of the sodium density profile overWuhan, China and the comparative research between calculation and observationresult are reported, and some factors that may influence the density distribution ofsodium layer are discussed.

NUMERICAL SIMULATION OF A CYLINDRICAL ELECTROSTATIC ANALYZER

YU Dejiang

1999, 19(1): 61-68. doi: 10.11728/cjss1999.01.061

Abstract(1637) PDF 478KB(1153)

Abstract:
Numerical simulation is made to SSJ/460°cylindrical electron detector boardedon DMSPsatellites. The potential distribution in the analyzer is found from solvingLaplace equation by means of SORiteration procedure. Based on the numericalsolutions of path equation, the responses of the detector are computed by using MontCarlo method. The appropriate choice of time and energy scale in the simulationleads to simple scaling laws of the response functions and the geometrical factor.

DYNAMICS OF FLEXIBLE MULTIBODY SYSTEMS USING NONLINEAR EXPRESSION OF DEFORMATION FIELDS

YAN Shaoze, WU Delong, HUANG Tieqiu, LIU Youwu

1999, 19(1): 69-75. doi: 10.11728/cjss1999.01.069

Abstract(1679) PDF 413KB(931)

Abstract:
Convention.al modeling methods for dynamics of flexible multibody systemshave been widely believed that dynamic equations by using methods are unavoidably linearized prematurely in deformation coordinates, which results in loss of dynamic stiffening terms in the equations. This paper presents a multi-flexible-bodydynamics formulation incorporating a recently developed theory based on nonlinearexpression of deformation fields over a flexible body undergoing large motion accompanied by small vibrations. The deformation fields are described by second ordernon-linear form of deformation coordinates, and equations of motion including dynamic stiffening terms are derived by means of Kane's method. Simulation resultsof a rotating flexible body, involving stiffening during spinnup motion, demonstratethe validity and generality of the theory presented in this paper.

THE EXPLOITATION OF SATELLITE FAULT DIAGNOSIS SYSTEM ON AGENT-BASED TECHNOLOGY

ZHU Ping, HUANG Wenhu, JIANG Xingwei, WANG Rixin

1999, 19(1): 76-81. doi: 10.11728/cjss1999.01.076

Abstract(1705) PDF 436KB(1022)

Abstract:
An intelligent Agent-based, distributive fault diagnosis model is presented inthis paper and a prototype system for satellite fault diagnosis developed. Thesystem uses Client/Server integrated structure. It could satisfy the engineeringneed for fault diagnosis. And a new analytic method and measuresg which make theparallel and synchronal multi-fault diagnosis possible is also provided.

A NOVEL UNIVERSAL DEMODULATOR FOR REMOTE SENSING SATELLITE

PAN Changyong, GUO Xingbo, YANG Zhixing

1999, 19(1): 82-87. doi: 10.11728/cjss1999.01.082

Abstract(1592) PDF 270KB(1334)

Abstract:
Anovel universal demodulator for remote sensing satellite is proposed and realized in this paper. Compared with traditional multiple-function demodulator, thisdemodulator is much simpler mainly due to a new kind of filter and programmablebit synchronizer. This device has already been field tested with satisfactory result.

THE INNER HELICITY OF PROMINENCE WITH HELICAL STRUCTURE

WU Guiping, XU Aoao

1999, 19(1): 88-91. doi: 10.11728/cjss1999.01.088

Abstract(1683) PDF 262KB(947)

Abstract:
The magnetic inner helicity of the prominence with belieal structure is inferredin this paper. Using the observational data, the value of inner helicity is calculated.It is shown that. (1) the scale of the inner helicity is related to the stability of thebelieal prominence; (2) the quiescent prominence has smaller inner helicity, whilethe eruptive prominence has larger helicity; (3) in the whole evolutional processof the prominence (e.g. quiescent-eruptive- stable ), t he helicity increase s firstly andthen it is transferred to the high corona.

EFFECTS OF THE SOLAR ECLIPSE ON f₀F₂ AND ICF FOR LOW LATITUDE REGION

ZHANG Tianyi

1999, 19(1): 92-96. doi: 10.11728/cjss1999.01.092

Abstract(1559) PDF 411KB(855)

Abstract:
The variations of the critical frequency of F₂ layer (f₀F₂) and the HFinterference centroid frequency (ICF) at Guangzhou and Haikou during the solar eclipseoccurring on Oct. 24, 1995, are presented. The morphology of f₀F₂ for two differentstations is not completely same for the same solar eclipse; the mophology of thesame station is not completely same duing the different solar eclipse; and ICF isnot as lower as Predicted. So, it is thought that dynamics may play a more important role in low latitude region than photochemistry related directly to the solarradiation.