1997 Vol. 17, No. 3

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A MODEL FOR THE SOLAR WIND AND CORONA WITH ENMRGY SUPPLIED BY HIGH FREQUENCY ALFVEN WAVES
ZHU Xiaomei, TU Chuanyi, HU Youqiu
1997, 17(3): 193-199. doi: 10.11728/cjss1997.03.193
Abstract(1914) PDF 421KB(1020)
Abstract:
A set of converging soluhons of a time dependent two-fluid model of the solarwind and the corona is presented. This model is based on the heating and accelerationeffects of high-frequency waves in the frequency range between lth and 400Hz. Thishigh frequency waves are assumed to be generated by the small-scale magnehc activityin the chromospheric network. The converging property of the solution and theconservation of the mass, momentUm and energy fluxes are also described. The modelresults can explain major properies observed in top transition region, corona and thehigh speed streams in the solar wind.
INTERACTION BETWEEN INTERPLANETARY STRUCTURE AND PERPENDICULAR COLLISIONLESS SHOCK
LU Quanming, LI Yi, WANG Shui
1997, 17(3): 200-205. doi: 10.11728/cjss1997.03.200
Abstract(1891) PDF 387KB(775)
Abstract:
By using an one-dimension hybrid code, the intenation between two kinds ofinterpanemp structure-the reverse magnehc field and the plasmoid with highdensity, and perpendicular collisionless shock is studed numerically The results showthat as the magnetic field on upstream of a shock reverses the magnetic field indownstream changes its sign gradually and the stronger turbulence is formed in thedistributions of plasma density and velocity. The parameter in upstream anddownstream of the shock still satisfy the Rankine-Hugoniot relation. When theplasmoid with high plasma density passes through perpendicular collisioniess shock, apart of protons is reflected, the others are accelerated by shock and enter thedownstream. Since that the distribution of proton velocity in the downstream is innon-Maxwell distribution, the stronger turbulence is also excited.
CHARGE FLUCTUATION AND ELECTROSTATIC WAVES OF DUST PLASMA IN COMETARY ENVIRONMENT
SHI Zhidong, LI Zhongyuan, WANG Xuyu
1997, 17(3): 206-211. doi: 10.11728/cjss1997.03.206
Abstract(2132) PDF 411KB(912)
Abstract:
In this paper, charging processes of dust grains immersed in plasma are analysed.A set of self-consistent three-fluids equations are given for dust plasma. From theseequations, fluctuation of charge on dust gtaln is studied and dispersion relations arederived for electrostatic waves in a unmagnihzed dust plasma. The influence of chargefluctuation on electrostatic waves is discussed for space dust plasma
A THEORETICAL LOW LATITUDE IONOSPHRIC MODEL
TU Jiannan, LIU Libo, BAO Zongti
1997, 17(3): 212-219. doi: 10.11728/cjss1997.03.212
Abstract(1946) PDF 742KB(1730)
Abstract:
A theoretical low-latitud ionospheric model is presented. The continuity andmomentum equations of O+, H+ are solved, using operator splitting difference schemeon the fixed grid points distributed along the magnehc fields. Molecular ion densitiesof N2+, O2+, NO+ are calculated under the assumption of photochemical equilibrium.The modeling results fairly reproduced the gross features of daily development ofequatorial anomaly observed in East Asia under equinochal, solar maximum conditions.It is also shown that HWM90 model estimates much too large nighttime windvelocities at low latituds in East Asia, and the vertical drift velocity in East Asiamay be smaller than that in American region.
A STUDY OF THE SECULAR VARIATION OF THE RATE OF THE EARTH'S ROTATION BY MEANS OF A HAMILTONIAN METHOD
XIA Yifei, XIAO Naiyuan, CHENG Zhuo
1997, 17(3): 220-226. doi: 10.11728/cjss1997.03.220
Abstract(1841) PDF 411KB(845)
Abstract:
In this article, the secular rotational varitation of the Earth whose elastic mantle isdeformed by gravitational attraction of the Moon and the Sun is studied by means ofa Hamiltonian method. The expression of the tidal potential with phase lag is given.The value of the secular deceleration of the Earth's rotation is obtained for the Earthmodel PREM. It theoretically is -5.7×10-22 rad / s2, which agrees perfectly with thelatost observational results. The results also show that the principle contribution to thisdeceleration is the sectorial tide corresponding to the term m = 2, and that thedeformation produced by the Moon is much more importan than that due to the Sun.
SOME CHARACTERISTICS OF SOLAR PROTON EVENTS AND MICROWAVE BURSTS
GAO Zhengmin, FU Qijun
1997, 17(3): 227-233. doi: 10.11728/cjss1997.03.227
Abstract(2001) PDF 405KB(884)
Abstract:
The proton eventS data provided by NOAA and the radio mulh-band 0bservationsprovided by SGD are analyzed stahshcally. The pumose is t0 search somecharacterishcs in the correlatons among CM-wave bursts, MM-wave bursts and protonevents. Some new results on this relation are presented in this paper.
THE OBSERVATION ANALYSIS FOR THE SUBTYPES OF FAST FINE STRUCTURES OF SOLAR MICROWAVE RADIO RADIATION
XIE Rinxiang, WANG Mn
1997, 17(3): 234-242. doi: 10.11728/cjss1997.03.234
Abstract(2265) PDF 593KB(648)
Abstract:
29 fast fine strUCtUres (FFS) were found after analizing lO3 edo bUrStS observedfr0m Janump l990 t0 January l994 with the 4-frequency (l.42, 2'l3, 2.84 and 4.26Gth) solar rado high temPoral resolution synchron0us system at Yunnan Observatory.SPecially, 2 rare subtyPes of the FFS, i.e. narrow-band Period vmping Pulsation andwideband slowly drifting long-periodic Pulsahon were found. 0ne occuered ddring theimPulsive Phase 0f flare and the other during the decaying Phase- Ths shows thatcoronal nonthermal electr0n anceleration / injechon process may go through the wholedevelopment process of flares. ndo FFS may be regardd as the evidence ofndcarenergy release of flares, and resulhng from the nonthermal electron acceleration /injechon. The many information abollt the ndcmtwta of the hme and sPaCe inflares asceleration mechhosm may be extheted from FFS. Genetally, the basic processof energy release is the illtomehon betWeen different magnehc stfUCbes, and hencethere may exist the magnehc reconnechon in the POst Phase of flare and the refondngof loop-like strUctures (Postflare loops) by the existence of FFS of the post Phase offlares.The unusual subtypes of FFS introduced here may reflect the specific environmntal conditions existing in corona even though their radation mechanism is the same as the basic types of FFS. Some complex and multi-type magnetic structures in coronamay be suggested by the various subtypes of FFS.
STRENGTH INDEX FOR X-RAY FLARE
LIU Shaoliang, HU Xiaolong, WANG Jialong
1997, 17(3): 243-247. doi: 10.11728/cjss1997.03.243
Abstract(2145) PDF 330KB(896)
Abstract:
Using the data averaged 0ver one minute 0bserved by G0ES-7, the relation ofsoft X-ray burst character with source strength for six large Xray flares in Marehand June l99l has been studied. The result shows tha for the flares with intense softXray burst the fastor the flux increases with hme at beginning, the larger the flare-as-sociated shock velocity in corona is. The numerical simulation result reveals that therelease speed of energy may be the main index for a burst source.
USE TWO-FREQUENCY CO-SPECTRUM OF INTERPLANETARY SCINILLATION TO COMPUTE THE VELOCITY OF SOLAR WIND
YE Pinzhong, SONG Xisheng
1997, 17(3): 248-254. doi: 10.11728/cjss1997.03.248
Abstract(2100) PDF 463KB(902)
Abstract:
The possibility of computing the velocity of solar wind by means of co-spectrumtechnique at two frequency 232 WHz and 327MHz is discussed in thes paper. Whenthe effect of integrahon is considered at the elongations 17°-50° with some possiblevelocity distribution, the derived results from co-spectrm tochnique indicate adeviation less than 15% from the velocity of solar wind.
APPLICATIONS OF BP NEURAL NETWORKS IN FORECASTING SUNSPOT NUMBERS FOR SOLAR CYCLE 23
TIAN Jianhua
1997, 17(3): 255-260. doi: 10.11728/cjss1997.03.255
Abstract(2053) PDF 412KB(1331)
Abstract:
BP neuraI networks were designed, thened and used t0 caregorize the data set andrecognize pattems in sunspot number vallation during the ascent and descent of solarcycles- A hist0rical data set of smo0thed monthly mean sunsPOt numbers for l75O ADtO the first half of l995 AD and the predicted values f0r the latter half of l995 tol996 were used. We 0btained good simulation results of the ascending Periods and smoothed monthly mean sunspot numbers for each ascent Period of Solar Cycle l-22and fairly good forecasting results of the ascending Period and the maximum ofsmoothed monthiy mean sunspot number for Solar Cycle 22- Flnally, the paper givesthe following eshmared values for Sol4f Cycle 23: The maximum of smoothedmonthly mean sunspot number is l96 and the ascending Period is 38 months-
A CASE STUDY OF TURBULENT ENERGY DISSIPATION RATES IN THE RANGE FROM 82 TO 92 km
WU Yongfu
1997, 17(3): 261-267. doi: 10.11728/cjss1997.03.261
Abstract(1863) PDF 457KB(915)
Abstract:
Vertical velocity and temPerature data observed from Chaf and Faling SPhererocket S are used to study the str Ucture and generah0n 0f tUrbulence. ResultS indicatethat a mulh - layered turbulent statllre is observed. G0od cormlation is foundbetween the strong turbulent layer, dyndrical instability and radar echo power,suggeshng that the str0ng tuthulent lnyer and echo power are relared to the dynamicalinstability.Vertical wavenumber sPectrUm of h0rizonta wind indicares tha there is anexcellent agreement with the saturated spectral model, suggeshng that the strongturbulent layer and radar echo power are linked directly to the saturation of gravitywave motions via dynamical instability.
THE CRITERION OF SIMULATION FOR THE PARACHUTE MODULE DECK IN GROUND TEST OF EJECTION
LI Dayao
1997, 17(3): 268-273. doi: 10.11728/cjss1997.03.268
Abstract(1815) PDF 279KB(1093)
Abstract:
Based on the principle of dynamics, the equations of motion of parachute moduledeck relative to the main bod of ballistic-lifting recoverable vehicle in the ejectionfor flight and ground tost are obtained, Then, the criterions of simulatioll for thepaxachute module. deck in ground test of ejection are given. The need for additionalforce in ground simulation test is discussed in this paper.
FINITE ELEMENT SOLUTION OF THE HYDRO-ELASTIC VIBRATION IN THE COMPLICATE STORAGE TANK
YUE Baozeng, WANG Zhaolin, KUANG Jinlu, LI junfeng
1997, 17(3): 274-281. doi: 10.11728/cjss1997.03.274
Abstract(1803) PDF 420KB(1159)
Abstract:
Semi-analytical finite element method is applied to reduce the hydroclashc problemof the fluid filled spherical tank with damping spherical shell to two dimensionalproblem, the Gaerkin method and Hamilton principle is used respectively to productthe system equation of flind and dampng spherical shell. Annular triangular element isused in fluld domain, the conical frustum element is used in damping spherical shell.
ON THE INFLUENCE OF ATTITUDE MOTION ON THE LEVELS OF MICROGRAVITY IN A DROPCAPSULE
LOU Yue, WANG Linhua, SUN Xianfan, NING Wenru, FAN Yuezu
1997, 17(3): 282-288. doi: 10.11728/cjss1997.03.282
Abstract(1756) PDF 348KB(1077)
Abstract:
The method of experimental uniform design, theoretical computations and computersimuations were used in the research on the influence of attitude motion on the levelsof microgravity in the dropcapsule. It is shown that an attitude control system must be set up on the dropcapsule if one wants to keep 60s of microgravity time withmicrogravity levels less than l0-3g.