空间科学学报

1982 Vol. 2, No. 4

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THE GENERATION MECHANISM OF SOLAR METRE-WAVE MOVING TYPE IV BURSTS

Li Hong-wei

1982, 2(4): 261-268. doi: 10.11728/cjss1982.04.261

Abstract(1808) PDF 609KB(942)

Abstract:
In this paper a new model and radiation mechanism of type IVmAbursts are presented.Plasma clouds ejected during the exposive phase of flare move upward inside a large magnetic arch,trapped nonthermal electrons (E≈100 KeV) with forward-cone gap distribution excite Langmuir wave.Under the condition T_e>>T_i there should be ion-sound wave in the source.The electromagnetic transverse wave is produced through the nonlinear interaction between the two waves and the type IVmAburst takes place.The spectra of brightness temperature and their evolution for eight announced events are calculated and the results coincide with observations rather well.The other main characteristics of the bursts,such as polarization,life-time,the relation between the size and position of sources and frequencies etc.,are all explained more reasonably.The radiation processes under conditions T_e=T_i and T_e>>T_i are compared with one another.It is shown that the condition T_e>>T_i is more probably true,so the main contribution to the radiation doesn't come from iou scattering,but from the nonlinear process l±s(这里有图片19820101-261-1.GIF)t.This conclusion is not only true for the type IVmAbursts,but also probably for some other types of solar radio bursts.

THE RADIO BURST RADIATION OF HALE 17590 ACTIVE REGION

Zhou Ai-hua

1982, 2(4): 269-274. doi: 10.11728/cjss1982.04.269

Abstract(2013) PDF 517KB(603)

Abstract:
Basing upon the observations of HALE 17590 active region,we investigated the radiation characteristics of radio bursts of this active region and found that: 1) In the rising period of development of the active region,there is also a corresponding change in intensity from weak to strong for each series of radio bursts,while the spectrum changes from monotonic to irregular or U type.2) For large flare bursts,the occurrences of the precursor phase are earlier in radio bursts than in X-ray bursts.The precursor radiation in radio bursts often companys with activation of filaments and enhancement of brightness of plage and so on.3) For large flare bursts,the time of impulsive maximum comes firstly in 8 mm wavelengh.

REDUCTION OF SOLAR IRRADIANCE BY THE PRESENCE OF EFFECTIVE SUNSPOTS AND VARIABILITY OF SOLAR IRRADIANCE BY THE PRESENCE OF EFFECTIVE PHOTOSPHERIC ACTIVE FEATURES

Li Zai-kun

1982, 2(4): 275-280. doi: 10.11728/cjss1982.04.275

Abstract(2134) PDF 595KB(1189)

Abstract:
This paper presents a new idea by modelling the reduction of solar irradiance by the presence of effective sunspots.Based on the author's personal conservative measurement of the sunspot pictures of April 1 through July 16,1980,a comparison between the theoretical solar irradiance and the total solar irradiance measured by SMMspacecraft has been made,which shows a reasonably good agreement and high correlation (r=0.78).Moreover,the author presents further an improved model of solar irradiance variability by the presence of effective active features on the photospherie disk,which is as follows.here Au,Apu,Af and A,denote the areas of umbrae,penumbrae,faculae and the visible solar disk,respectively;θu,θpu,θf are the umbral,penumbral and facular contrast values;θfh represents the limb darkening that depends on the helioeentric-angle θ.The author also sets forth several problems that need further investigations.

A DISCUSSION ON THE PROPERTIES OF MHD SHOCKS IN TERMS OF THE CHARCTERISTIC VELOCITY

Zhang Gong-liong, Jiang He-rong

1982, 2(4): 281-293. doi: 10.11728/cjss1982.04.281

Abstract(2678) PDF 946KB(853)

Abstract:
This paper discusses analytically the categories and properties of the MHDshock in terms of the characteristic velocity U_* as its fundamental strength parameter,which was presented by the author (See Reference [1]).A detailed discussion is given on the variation of the jump ratio of magnetic field intensity h as a function of the square of the characteristic Mach number M_*²=U_*¹/C₁². The results are also given of the jump ratio of the fluid density p, pressure P, normal and tangential velocities [u_x]/C₁ and [u_y]/C₁. Finally, the limit cases of MHD shock, i.e. the perpen-dicular and parallel shocks including the switch-on and switch-off ones (Fig. 6) are discussed.

THE INFLUENCE OF THE MAGNETOPAUSE ON MAGNETIC FIELD WITHIN THE MAGNETOSPHERE

Wu Hong-zhong, Du Heng

1982, 2(4): 294-303. doi: 10.11728/cjss1982.04.294

Abstract(2246) PDF 727KB(736)

Abstract:
The magnetopause exerts a tremendous influence on magnetic field within the magnetosphere.In this paper we have calculated the magnetic field of the magneto-pause on following assumptions: (1) the earth's magnetic field is a dipole field;(2) the magnetopause is an ideal conductor so that the perpendicular component of the total magnetic field at the magnetopause is zero;(3) the magnetopause is regular and is composed of three parts: a hemisphere,a cylinder and a cap.At first we evolute the spherical harmonic coefficients by the method of least square,then trace the magnetic field lines by means of numerical integral.The results are that on sunward side the magnetic field,especially the position of the neutral point and the shape of the polar cusp are close to the observational results.But on anti-sunward side,in the vicinity of the equator the calculated magnetic field lines are not parallel to the equator,this result indicates that the effects of the current sheet in the magnetotail can not be neglected in this region.We have made this calculation for three angles between the magnetic dipole and the direction of the solar wind: 90°,the average situation of the earth's magnetosphere;60°,the extreme situation of the earth's magnetosphere;and 0?the situation of the Uranus' magnetosphere.

INFLUENCES OF THE ION TEMPERATURE ON THE NONLINEAR ELECTROSTATIC WAVES IN MAGNETIZED PLASMA

Zhou Guo-cheng, Shi Jian-kui

1982, 2(4): 304-311. doi: 10.11728/cjss1982.04.304

Abstract(1841) PDF 600KB(869)

Abstract:
In this paper the influences of the ion temperature on the nonlinear lowfre-quency electrostatic waves in a magnetized low-β plasma are discussed.It is found that there exist three types of nonlinear waves under the parameter a T_i/T_e≠0 (where T_i and T_e are the ion and electron thermal energies respectively) : (i) nonlinear ion-cyclotron periodic waves with a wave speed ν_p>(1+α)^{(1/2).c_s (where c_s,is the ion acoustic velocity) (ii) ion-acoustic solitons with (1+α)^{(1/2)c_s.cosθp<(1+α)^{(1/2).c_s and (iii) nonlinear ion-acoustic periodic waves with v_p<(1+α)^{(1/2).c_s.cosθ (where θ is the angle between the wave vector and the magnetic field).Moreover,the maximum electric potential θ_m of the soliton decreases and the amplitudes of the electric potential for both nonlinear periodic waves are almost constant when the parameter a4 increases.}}}}

USING THE DRESSED TEST PARTICLE APPROACH TO DEDUCE THE SCATTERING POWER SPECTRUM OF RADIO WAVES BY A QUASI-EQUILIBRIUM IONIZED GAS IN THE PRESENCE OF AN EXTERNAL MAGNETIC FIELD

Chen Zhi-yu

1982, 2(4): 312-318. doi: 10.11728/cjss1982.04.312

Abstract(2016) PDF 535KB(918)

Abstract:
The expression of scattering power spectrum of radio waves by a quasi-equilibrium plasma in the presence of a magnetic field had been previously obtained by a number of authors with respective methods in investigating the incoherent scatter theory.Their results,based on the Boltzmann equation,are identical.In this paper,using the dressed test particle approach given by Rosenbluth and Rostoker (1962),but employing a diffrent mathematical thechnique from theirs,the same result is obtained.We still start from the Vlasov equation and the Poisson equation,but adopt the way of solving differential equation and repeatly taking Fourier transform.The key lies in applying the convolution theorem to relate the time autocorrelation of electron density fluctuations with the function (这里有图片19820407-312-1.GIF) which can be directly calculated from the unperturbed orbits of charged particles.Hence the procedure is comparatively concise and straightforward.

THE DIFFUSION MODEL USED IN PPT AND THE SOLUTION OF THE REDUCED MHD EQUATION SYSTEM

Wei Eong-hua

1982, 2(4): 319-326. doi: 10.11728/cjss1982.04.319

Abstract(1898) PDF 628KB(927)

Abstract:
Based on the early theoretical models describing the discharge process of thePulsed Plasma Thruster,a new model----diffusion model----is presented in thispaper The model considers both the real g eometry of the discharge channel of the PPTand the behavior of the plasma in it.The plasma is pinched into a narrow region at the begining because the current is very high (the peak value varies from 10³ A to 10⁴ A),and then it expands along the channel as a result of the diffusion under the density and the temperature gradient as the discharge is going on.It is postulated that the plasma volume is not constant as described in the earlier papers,but small at first,and then increases with time.Moreover,it changes with the position of plasmoid.As a result,the inductance of the discharge circuit can be written as a function of channel geometry and plasma situation.It's expression is seen in this paper.Suppose the resistance is constant as usual,the reduced MHD equation system can be solved by means of computer.Two different channels of each of the three models including this one have been calculated under the same conditions.Two test thrusters have been constructed for comparison.The main values obtained from measurement and calculation by means of the three models are listed together,and some of the curves given by the diffusion model are plotted.It has been established that most results we are interested in,such as the specific impulse,the peak values and the periods of discharge current,calculated by the diffusion model are much near to the tested values.Therefore,it is proper to describe the PPT's operation with the new model.

THE OBSERVATION OF INFLUENCE ON THE CHARACTERISTICS OF CARDIOVASCULAR RESPONSE DURING BED REST

Zhuang Xiang-chong, Fan Ya-ming, Xiang Qiu-lu, Sun Ya-shi, Li Shu-chun

1982, 2(4): 327-334. doi: 10.11728/cjss1982.04.327

Abstract(2241) PDF 732KB(1048)

Abstract:
During the stress of head up tilt plus lower body negative pressure,the subjects' cardiovascular responses might be divided into four characteristics: vascular type,mixed type,cardiac type and less regulating (lower efficient) type.The regulating characteristics of vascular type mainly showed an increase of total peripheral resistance during stress.The mixed type had an obvious increase of both heart rate and total peripheral resistence.The cardiac type appeared obvious in the increase of heart rate.The less regulating type couldn't be sufficiently regulated in both heart rate and total peripheral resistance.The subjects of vascular type was showed the best tolerance of the stress,then those of the mixed,and then those of the cardiac.The subject of less regulating type showed the worst tolerance.During bed rest,the subjects' feeling and the objective examinations also showed the vascular and the mixed types were better than the other two types.Before and after bed rest,the characteristics of reaction to this stress were similar intraindivi-dually.Data might be treated with the concept of fuzzy sets.The difference among different characteristics of cardiovascular reactions might be quantitatively compared.

THE CORRELATIONS BETWEEN THE TYPHOON AND THE f₀ F₂ OF IONOSPHERE

Shen Chang-shou

1982, 2(4): 335-340. doi: 10.11728/cjss1982.04.335

Abstract(2262) PDF 502KB(1231)

Abstract:
The effect of typhoon on the critical frequency of the F₂ region has been studied by using the observations made in 1969,1970,1972,1973.There are 21 observations of typhoon crossing or passing by Hainan chosen to compare with the simultaneous ionospheric data of the same area.It is found that there are evident correlations between the passage of the typhoon and the f₀ F₂.It is indicated that the f₀ F₂ decreases in the area right above the centre of the typhoon,but increases in the surrounding area.We suggest that the strong vertical convection in the troposphere caused by typhoon can change the local circulation system in the stratosphere and mesosphere,and this would influence the f₀ F₂ (e.g.number density of electrons in F₂ region) through the change of the height of the turbopause and the change of the ratio of atmospheric composition in the F₂ region.The result of this work shows that the study of the effect of the typhoon on the upper atmosphere is an applicable method for the research of the coupling between the upper and lower atmospheres.

DETERMINATIONS OF TRACE ELEMENTS IN SOME STONY METEORITES BY INSTRUMENTAL NEUTRON ACTIVATION ANALYTICAL METHOD

Zhao Yun-long, Xing Lian-shan, Zhong Pu-he, Zhou Xiao-xia, Wang Zi-xiang, Ouyang Zi-yan

1982, 2(4): 341-344. doi: 10.11728/cjss1982.04.341

Abstract(1968) PDF 375KB(926)

Abstract:
12 trace elements in six pieces of stony meteorites of Anlong,Dongtai,Yangjiang,Jilantai,Jilin,Qingzhen have been determined with Instrumental Neutron Activation Comparing method in which USGS's standard rock G-l is used as direct multielement standard.These stony meteorites is ground into powder and devided into two parts of magnet and nonmagnet.Some of the monoelement liquid standard and the standard rock G-l have simultaneously been tested with the comparing check analysis method of which the results are coincidence each other,so as to check the accuracy of the method discussed.