空间科学学报

1996 Vol. 16, No. 4

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A STUDY ON THE PUMPING MECHANISM OF CLASS Ⅱ CH₃ OH MASERS

Zheng Xing-wu, Ling Zhao-fen, Liu Gin-xia

1996, 16(4): 251-259. doi: 10.11728/cjss1996.04.251

Abstract(2069) PDF 593KB(824)

Abstract:
The association of CH₃OH masers with far-infrared sources is inveshgated in this paper. A strong correlation between the maser and infrared luminosities appears to show an infrared excitation for the CH₃OH masers.

THE INFLUENCE OF DISPERSIVE AND DISSIPATIVE EFFECTS ON THE FORMATION OF ALFVEN SOLITON WAVES

Feng Xue-shang, Lu Jian-yong

1996, 16(4): 260-265. doi: 10.11728/cjss1996.04.260

Abstract(2302) PDF 257KB(1337)

Abstract:
Using some variable transformations and analytical integration, the analytical solitary wave solutions are obtained for the dispdrive DNLS equation and dissipative MKdV equation, which describe the propagation of Alfven waves in various plasma medium. Meanwhile, the ekistence conditions of soliton-like solutions are given.

KINETIC ALFVEN WAVE RE-EXCITATION AND TURBULENCE SPECTRUM IN THE SOLAR WIND(b)

Song Li-ting, Wei Feng-si

1996, 16(4): 266-273. doi: 10.11728/cjss1996.04.266

Abstract(2459) PDF 538KB(914)

Abstract:
When the velocity of the solar wind is accelerated to Alfven speed u_A, Landau damping of original kinetic Alfven waves subspends and the kinetic Alfven wave is excited second time. The velocity of propagation of newly excited Alfven waves with the wind is U+u_A,the velocity of propagation against the wind is U-_A, the former suffers Landau damping and the latter gives Z⁺ mode and has no damping. The interplanetary Alfvenic turbulence is divided into three regions: dissipative region of turbulence(R<0.2AU), re-exciting region (0.2AU0.4AU), and an explanation of the turbulence spectrum features in different region is given. Based on the re-exciting and damping of the kinetic Alfven wave, the fact of higher temperature of proton in high speed stream of the solar wind is explained in this paper.

A GLOBAL MODEL OF MAGNETIC RECONNECTION AT MAGNETOPAUSE FOR NORTHWARD IMF

Zhang Hong, Liu Zhen-xing

1996, 16(4): 274-281. doi: 10.11728/cjss1996.04.274

Abstract(2514) PDF 628KB(1005)

Abstract:
A 2D compressible model is used to simulate the local magnetic reconnection at the nightside magnetopause for northward IMF. Based on the simulation result, a globe magnetic reconnection model for northward IMF is proposed. As results of magnetic reconnection at magnetopause for northward IMF, the magnetic energy in tail lobe is transported to far magnetotail, dayside magnetopause become thicker, and the magnetosphere is disturbed.

POLYTROPIC INDICES IN INTERPLANETARY SHOCK

Liu Shao-liang, Tang De-shuang, Liu Si-qing

1996, 16(4): 282-286. doi: 10.11728/cjss1996.04.282

Abstract(2463) PDF 383KB(891)

Abstract:
From the data observed by Helios et al. during 1972 to 1987, 986 interplanetary fast shocks are picked out and the most appropriate polytropic index for every shock is determined by applying MHD Rankine-Hugoniot relations. The results demonstrate that the values of polytropic index scatter in a certain range, and the most probable value is approximately between 1.70 and 1.75.

A NUMERICAL EXPERIMENT OF INTERACTION BETWEEN SPACE PLASMA AND PERPENDICULAR COLLISIONLESS SHOCK

Lu Quan-ming, Li Yi, Wang Shui

1996, 16(4): 287-292. doi: 10.11728/cjss1996.04.287

Abstract(2292) PDF 358KB(1037)

Abstract:
The interaction between space plasma and a high Alfven-Mach number perpendicular collisionless shock using a hybird simulation is numerically studied. The results show that in the upstream the magnetic field is very stable, and the distribution of the proton is nearly a Maxwell distribution. In the downstream the magnetic field eaists the irregular turbulence. The distribution of protons has a high energy tail and few protons 4ie reflected. Following some protons with high velocity, it is found that at t=40Ω_i^-1 about 40% of protons are reflectal by shock, and 7% of protons are accekerated(maximum velvcity up to 20V_A). The electric field in shock region has gureat influence on the deceleration and acceleration of protons.

RECURRENT LAW OF THE ACTIVE REGIONS OF PROTON FLARES

Zhou Shu-rong, Wu Ming-chan, Ni Xiang-bin

1996, 16(4): 293-298. doi: 10.11728/cjss1996.04.293

Abstract(2469) PDF 475KB(1174)

Abstract:
Recurrent law of the active regions for proton flares are studied in this paper. The results indicate that on the sun there are "active volcanos" of the motion along longitude, that is active reviviscent bodies of the proton flares. In 22th solar activity cycle, there are two stronger active reviviscent edes of the proton flares on the sun, they are in two latitude bands of 26°- 35°N and 20°30°S. The proton flares with peak fluses≥100pfu and ≥1000pfu produced by these reviviscent bodies are about 70.7% and 83.3% of those on the solar disk. Long periods of the revivifications for active reviviscent bodies are about 8- 11.6 years, short periods are 1-2.6 years. Due to long and short periods of the revivification for the reviviscent bodies consist with 11 years periods of the solar activity cycle and time interval of the peak years, therefore, the periodic revivifications of the active reviviscent bodies can be important cause of the 11 years periodic variation of the solar activity cycle and intensive eruptions of the flares during solar active maximum.

TYPE Ⅲ BURST SOURCES IN THE CORONA AND COMPARISONS WITH THE INTERPLANETARY MAGNETIC FIELD LINES

Ji Shu-chen, Cao Wen-da, Wei Feng-si

1996, 16(4): 299-304. doi: 10.11728/cjss1996.04.299

Abstract(2105) PDF 380KB(1251)

Abstract:
In thes paper, some high spacial and temperal resulation data observed with the Nancay Mark Ⅲ Radio heliograph in the period of 1980 March-1981 September are processed. It is found that a great number of Type Ⅲ burst sources in the corona are centralized near the ecliptic. Type Ⅲ burst sonrces located in the north of the ecliptic are larger in number than those in the south; the west are larger in number than the east. For 92.0% Type Ⅲ burst sonrces are located within 40°of the ecliptic. After a comparison with the interplanetary magnetic field lines obtained with the radio spectrograph on board ISEE-3 in the same period, it is discovered that there are clear corresponding relations on latitude distribution between Type Ⅲ burst sonrces in the corona and the interplanetary magnetic field lines. It is evidene that the interplanetary Type Ⅲ burst sources originate from Type Ⅲ burst sources in the corona.

METEORIC PHYSICAL PROBLEM IN THE COLLISION OF SHOEMAKER-LEVY 9 ON JUPITER

Hu Zhong-wei, Chu Yi, Wu Yin-gen, Huang Ke-liang

1996, 16(4): 305-309. doi: 10.11728/cjss1996.04.305

Abstract(3242) PDF 326KB(628)

Abstract:
The collision of comet Shoemaker-Levy 9 with Jupiter is essentially a particular meteoric physical problem during the cometary fragments into Jupiter's atmosphere. In this paper, profile formula of their velocity, mass loss, luminosity, electron line density and energy release rate on height are derived from fundamental equations of meteoric physics. Using reasonable parameters, a series of results are calculated. The results are compared with observations and discussed. It is shown that initial mass of the largest fragment of SL9 is of order 10¹⁶ g and do not penetrate into H₂O cloud layer of Jupiter due to its airburst.

MAGNETIC DISTURBANCE DURING 1978-1988 AND THE SOLAR-TERRESTRIAL COUPLING

Shen Chang-shou, Zi Min-yun

1996, 16(4): 310-316. doi: 10.11728/cjss1996.04.310

Abstract(2472) PDF 482KB(862)

Abstract:
The data of IMF-B_z, auroral electrojet indices AL and ΔZ(the deviation of Z-component from geomagnetic quiet condition) near the equator during 1978-1988 are analyzed to discuss the solar-terrestrial coupling process. The results show that the 11-yearly variation of B_z is roughly corresponding to that of solar cycle activity. The variation of AL and ΔZ, however, are different. They are mainly controlled by physical processes in the magnetosphere and ionosphere. The international magnetic disturbed day(IMDD), chosen according to the A_p or K_p index, can represent the average level of the geomagnetic disturbance. The physical meaning of these indices, however, is nuclear. The disturbance level, the global feature presented and the physical process involved of IMDD from each month are different greatly. So, a new reasonable classification according to physical process is needed in futher study.

STANDING WAVE STRUCTURE IN THE ATMOSPHERIC TEMPERATURE DUE TO THE UPWARD PROPAGATING PLANETARY WAVES

Chen Pei-ren, Tian Jian-hua, Luo Yi

1996, 16(4): 317-321. doi: 10.11728/cjss1996.04.317

Abstract(2538) PDF 339KB(920)

Abstract:
The drily average temperature data from Stratospheric and Mesospheric Sounder(SAMS) on satelite Nimbus-7 are used to analyze the standing waye structure in temperature caused by the atmospheric planetary waves. Its distribution of wavelength and amplitude with height, and variation with latitude as well as longitude are shown respectively. A possible mechenism to explain this phenomenon is suggested.

PATH PLANNING FOR SPACE MANIPULATOR WITHOUT DISTURBANCE ON VEHICLE'S ATTITUDE

Gu Xiao-qin, Liu Yan-zhu

1996, 16(4): 322-325. doi: 10.11728/cjss1996.04.322

Abstract(2159) PDF 257KB(1289)

Abstract:
The problem on path planning of a space manipulator is discussed in this paper. The path planning methods avoiding or decreasing the disturbance on vehicle's attitude for a predetermined trajectory or initial and final positions of the payload of manipulator are suggested.

DYNAMIC PROPERTY ANALYSIS FOR SPACECRAFT WITH BEAM-LIKE DEPLOYING APPENDAGES

Zhu Gui-dong, Wang Beng-li, Shao Cheng-xun

1996, 16(4): 326-330. doi: 10.11728/cjss1996.04.326

Abstract(2196) PDF 455KB(1273)

Abstract:
This paper studies the attitude dynamics and vibration of appendages of spacecraft with deploying appendages. A spacecraft model of a center rigid body with some deployable beams are considered. The governing equations are derived based on characteristic function of bending beam, and the effects of deploying rate and disturbance on system behavior are investigated to find the criteria of the selection of deploying rate. The numerical simulation results are also presented.