1998 Vol. 18, No. 4

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STUDY OF HIGH SOLAR ACTIVITY IN FEBRUARY 1986 Ⅳ. A PRELIMINARY ANALYSIS OF THE RELATIONSHIP BETWEEN SOLAR AND TERRESTRIAL EVENTS
WANG Jialong, XIAO Zuo, GAO Yufen
1998, 18(4): 289-295. doi: 10.11728/cjss1998.04.289
Abstract(2368) PDF 479KB(660)
Abstract:
Using observational data in optical, radio, soft and hard X-ray bands, the similarity and differences between the two top intense solar bursts of the solar activity sequence in early February 1986 are analysed, and the differences between the effects caused by these solar activities are interpreted. A relation identification of these solar-terrestrial events shows that a synthetic method for the event identification would be usable and a model study of solar corona with inhomogeneous structures and of interplanetary medium with inhomogeneous statures would be very necessary for a further investigation of coupling of solar-terrestrial disturbance events.
THE TEMPERATURE DISTRIBUTION BETWEEN PROTONS AND ELECTRONS AND THE DISSIPATION OF KINETIC ALFVEN WAVES IN THE SOLAR WIND
XIAO Chijie, SONG Liting
1998, 18(4): 296-300. doi: 10.11728/cjss1998.04.296
Abstract(2354) PDF 316KB(946)
Abstract:
The dissipation energy ratio of kinetic Alfven waves between proton and electrons is calculated in details based on the dissipation principle of kinetic Alfven waves. It provides a simple explanation of the fact of the higher proton temperature compared with electrons in high speed stream of the solar wind. The rapid cooling of electrons at r<10Rs is explained qualitatively.
FORMATION OF DISTRIBUTION OF α PARTICLES IN HIGH SPEED SOLAR WIND
WANG Xueyi, C S WU, ZHOU Guocheng, CAO Jinbin
1998, 18(4): 301-307. doi: 10.11728/cjss1998.04.301
Abstract(2616) PDF 503KB(995)
Abstract:
In this paper a multi-step model is suggested to explain the observed acceleration o f a particles in the solar wind. The entire process starts in reconnection region in the lower coronal hole and continues in the interplanetary space down to 0.3 AU. It is proposes that the observed acceleration is attributed to the interaction between the α particles with intrinsic and excited ultra-low-frequency waves in the solar wind.
EFFECTS OF NEUTRAL WINDS ON NIGHTTIME LOW-LATITUDE IONOSPHERE
LIU Libo, TU Jiannan, BAO Zongti
1998, 18(4): 308-312. doi: 10.11728/cjss1998.04.308
Abstract(2253) PDF 339KB(1032)
Abstract:
Dynamic effects of neutral winds on nighttime low-latitude F-layer are studied using an improved theoretical ionospheric model. The modeling results indicate that the distribution of neutral wind is essential in the evaluation of nighttime low-latitude F region. It is also shown that some features of dynamical processes induced by neutral wind are different from previous expected.
PARAMETRIC EXCITATION PROCESS OF GRAVITY WAVE PACKETS IN ITS PROPAGATION
YI Fan
1998, 18(4): 313-322. doi: 10.11728/cjss1998.04.313
Abstract(2104) PDF 678KB(1074)
Abstract:
Parametric excitation is a mechanism to influence the energy transport of internal gravity waves. It manifests itself as a decay of a primary wave and growth of two secondary waves through resonant intetaction. Current research status on this issue stays still at the parametric instability in plane monochromatic internal gravity waves. By using a numerical method the temporal and spatial evolution of parametric excitation in propagating gravity wave packets is studied. It is indicated that through resonant interaction two secondary waves can in sevenal hours reach significant intensities above the noise level and possess considerable space area. The energy amounts which two secondary waves extract from the primary wave are different, exhibiting a parameter dependence of the energy transfer in a triad. The primary wave packet provides only a part of its initial energy to excite secondary waves. The primary wave packet is apparently deformed as it decays. This is caused by the localization in the energy transfer characteristics. The energy transfer among the interacting waves is no longer reversible since the propagating wave packets own limited space area. Thus the characteristic bine for the interaction is of particular significance. It represents a stage in which principal energy transfer arises. Beyond the characteristic bine the net energy transfer among the interacting waves becomes rather weak. The decay process for a gravity wave packet propagating from the mesosphere to the lower thermosphere can cop out sufficiently. Resonant interaction is not only able to diffuse wave energy across spectral space but tends to spread wave energy in physical space.
WARNING OF SOLAR PROTON EVENTS
HU Xiong, HUANG Zerong, ZHANG Xunxie, GONG Jiancun, XUE Bingsen, YE Zonghai
1998, 18(4): 323-328. doi: 10.11728/cjss1998.04.323
Abstract(2871) PDF 364KB(1204)
Abstract:
A new warning scheme of solar proton events was proposed in this paper. In this scheme, five parameters including the solar flare position in the sun, the peak flux of X ray radiations and its rise bine, the half integrated fluxes of microwave fadiations of 2695MHz and 8800MHz, were used to give a warning of the occurences of solar proton events and their peak flux and time with an ANN (Artificial Neural Network) method. A simple discription of ANN was given. Some historical data of solar flares and solar proton events were provided for ANN's training and test repectively. Results showed that the presented scheme has a prediction accuracy of 93.75%.
PREDICTION OF GEOMAGNETIC DISTURBANCES FOLLOWING SOLAR PROTON EVENTS (SPEs) WITH A NEURAL NETWORK
FAN Quanfu, TIAN Jianhua
1998, 18(4): 329-335. doi: 10.11728/cjss1998.04.329
Abstract(2161) PDF 514KB(1022)
Abstract:
By analyzing some typical SPEs, it has been found that geomagnetic disturbances are closely associated with SPEs. A SPE with the following features is most likely to be followed by a geomagnetic disturbance:1) There exists an intense proton flare. 2) The proton flux rises rapidly from background to peak and then declines in a relatively quick way. The same applies to the electron flux. 3) The electron flux is much greater than the proton flux. On the above basis, the neural network is designed tO predict the geomagnetic activity in the successive 3 days after the occurrence of a SPE.
ISOTOPIC ABUNDANCES OF NOBLE GASES IN SOME CHONDRITES AND MESOSIDERITES FELL IN CHINA
WANG Daode, Otto Eugster
1998, 18(4): 336-341. doi: 10.11728/cjss1998.04.336
Abstract(2201) PDF 418KB(916)
Abstract:
Noble gas isotopic abundance of Jiange, Yanzhuang, Bo Xian ordinary chondrites, Weiyuang and recently recovered Deng Ujimqin mesosiderites are measured by the standard procedure and mass spectrometer and results reported in this paper. Based on 3He, 21Ne and 38Ar, cosmic-ray exposure ages are calculated. Gas retention ages are determined based on radiogenic 4He and 40Ar for three chondrites. Cosmic-ray exposure ages of Jiange, Yanzhuang and Bo Xian are 5.8Ma, 2.5Ma and 38.0Ma, respectively. The average ages are 172Ma for Deng Ujimqin and 17Ma for Weiyuang mesosiderites. These ages represent the duration of exposure to cosmic-rays after break-up and ejection from their parent bodies.
STUDY ON SPACECRAFT ANOMALY CAUSED BY SPACE ENVIRONMENT
ZANG Zhenqun, GU Shifeng, SHI Liqin, WU Zhonghua
1998, 18(4): 342-347. doi: 10.11728/cjss1998.04.342
Abstract(2334) PDF 370KB(1415)
Abstract:
In this paper, about 10 years' dare of the spacecraft anomaly caused by space environment for the satellites (including SCATHA, TDRS-1, GPS and GOES) running near or on geosynchronic orbits are analyzed. For these anomaly, their yearly, monthly, hourly in local bine as well as different anomaly type distribution characters are studied respectively. The result shows that diversified space environment causes various types of spacecraft anomaly due to its different effects on spacecraft. (1) No general character exists for effects of long-term and/or short-term solar activities on spacecraft anomaly. (2) From a view of long-term, SEUs are mainly caused by heavy ions from galactic cosmic ray and solar proton event is not important to SEUs. (3) The study and prediction about space environment are very important and necessary to analysis, recognition, prediction and shielding for spacecraft anomaly.
THE ORBITAL PERFORMANCE ANALYSIS FOR SPACE EXPLORING SATELLITE WITH HIGH ECCENTRICITY
SHE Mingsheng
1998, 18(4): 348-355. doi: 10.11728/cjss1998.04.348
Abstract(2359) PDF 474KB(2092)
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The exploring satellite which operates on the high eccentricity orbit has many orbital characteristics. In this paper, SJ-4 satellite is taken as an example to discuss some features in satellite designed general operation, and the emphasis is put on the main characteristics of orbit design, and shows the data and figures which stand for orbital calculation, window, satellite's launching illumination and tracking conditions. It is pointed out that the accuracy of orbit design and initial attitude selection of the SJ-4 satellite has verified by the telemetric data in two months operation.
THE EFFECTS OF 7-DAY BED REST ON CARDIOVASCULAR AUTONOMIC REGULATION
XIANG Qiulu, MENG Jingrui, SHEN Xianyun, WANG Desheng, DONG Qi
1998, 18(4): 356-362. doi: 10.11728/cjss1998.04.356
Abstract(2180) PDF 450KB(932)
Abstract:
To examine the alterations in cardiovascular autonomic function and orthostatic tolerance induced by Simulated Weightlessness (SWL), the changes in Heart Rate Variability (HRV) spectra are studied in the way that 20min, + 75℃ Head UP Tilt (HUT) tests were conducted before and after a 7-day, -6° head-down bed teat for six healthy young male subjects. After bed rest, two of the six subjects could not complete the 20min HUT test that all have completed before. During bed test, the Low Frequency (LF) and High Frequency (HF) powers of HRV spectra were all significantly decreased, the ratio of low-to high-frequency power of HRV spectrum [(LF:HF)HRV] appeared to be increased at the end of bed rest. During the first 6min period of HUT after bed rest the heart rate was faster, but the (LF:HF) HRV, were similar to the data during HUT before bed rest in all subjects. The results suggest that the peripheral vascular sympathetic activity and the cardiac parasympathetic activity are decreased with a gradual increase in the cardiac sympathetic activity during bed rest but the cardiovascular autonomic responsiveness during HUT after bed rest seems to be unimpaired.
LIGHTNING CHANNELS AND FRACTALS
REN Shunping, CHI Jianping, ZHUANG Hongchun
1998, 18(4): 363-369. doi: 10.11728/cjss1998.04.363
Abstract(2338) PDF 418KB(1053)
Abstract:
The paper introduces the relationship between fractal and lightning in some detail and a new idea about fractal dymatic lightning model is put forward.
INVESTIGATION OF THE VERTICAL COMPONENT OF THE FILAMENT CURRENT CIRCUIT IN FILAMENT MODELS
LI Kejun, GU Xiaoma
1998, 18(4): 370-374. doi: 10.11728/cjss1998.04.370
Abstract(1765) PDF 312KB(840)
Abstract:
Based on some filament current models, which are usually used nowadays, the equation of force-balance of a current filament in the vertical direction has been deduced. The effects of the two kinds of cuurent, namely the current from the solar photosphere to a filament and that from the filament to the solar photosphere on the current filament are taken into account while deducing the equation. Then relation between the current filament in the active region NOAA 131 and its balance altitude is investigated according to the equation. The result obtained shows that when a filament rises, it may be bent into a "U" shape, which is clearly in contrast with observations. It is concluded that an elliptic circuit should be closer to the real filament than the rectangular circint.
FURTHER STUDY OF A TURBULENCE SPECTRUM
WU Yongfu
1998, 18(4): 375-380. doi: 10.11728/cjss1998.04.375
Abstract(1832) PDF 474KB(619)
Abstract:
A wind shear profile as high as 330s-1 at 87.4km was measured by a Chaff rocket. TIs wind shear is believed to be the largest value ever measured in the mesosphere. Spectrum of the vertical velocity fluctuations in the extremely large shear layer has spectral slopes of -3.10, -1.65 and -7.11 in the buoyancy subrange, the inertial subrange, and the viscous subrange respectively. ms observation is in good agreement with the neutral density fluctuations. While the calculated inner scale and buoyancy scale do not agree with the breakpoints in the spectrum of the vertical velocity fluctuations. ms result is not consistent with the neutral density fluctuations. The relationship between turbulence and gravity wave is studied. This result suggests that enhanced turbulence is linked well with wave field saturation.