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Table of Content

    24 December 1999, Volume 19 Issue 4 Previous Issue    Next Issue
    论文
    CHROMOSPHERIC MAGNETIC FIELDS OBSERVATION FOR QUIET-SUN REGIONS
    ZHANG Mei;ZHANG Hongqi
    1999, 19 (4):  289-294.  doi: 10.11728/cjss1999.04.289
    Abstract ( 1889 )   PDF (495KB) ( 1199 )   Save
    Using the solar magnetic field telescope in Huairou Station of Beijing Astronomical Observatory, the solar photospheric and chromospheric magnetic fields forquiet-Sun regions have been observed for the first time. By a study of deep magnetograms of solar photosphere, chromosphere and different levels of chromosphere,it is found that the network magnetic tubes do not diverge a lot from the solarphotosphere to the chromosphere, which is contrary to the popular canopy model'spredication. It is also found that the intranetwork magnetic tubes have reached thesolar chromosphere, which is also contrary to the dynamo model's Predication thatthe intranetwork magnetic tubes will not reach high atmosphere. This observationof solar chromospheric magnetic fields for quiet-Sun regions have challenged twopopular models of solar atmosphere.
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    THE EVOLUTION OF HARD X-RAY ENERGY SPECTRUM IN SOLAR FLARES
    LIN Huaan
    1999, 19 (4):  295-300.  doi: 10.11728/cjss1999.04.295
    Abstract ( 2244 )   PDF (531KB) ( 1338 )   Save
    The hard X-rays of solar flares are produced by Bremsstrahlung interaction ofhigh energy electron beam impinging on solar atmosphere. Based on a simple physical model of flare loop, and under the assumption that the high energy electronswith synchronous variation between the beam flux and spectrum index are injectedfrom the top of the loop, some calculated results about hard X-ray spectrum evolution with different atmosphere density are obtained in this paper. These resultsshow: in low density area, such as in the top of loop, the hard X-ray spectrum hassoft-hard--hard evolution property, in high density area, such as in the foot points ofloop, the spectrum possesses soft-hard-soft variation. The time duration of injectingelectrons will influence the height of region in the loop where the one type of hardX-ray spectrum evolution will transform into the other one.
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    A LARGE MICROWAVE TYPE IV RADIO BURST ASSOCIATED CME ON DECEMBER 16, 1988
    JI Shuchen;WEI Fensi
    1999, 19 (4):  301-307.  doi: 10.11728/cjss1999.04.301
    Abstract ( 1957 )   PDF (437KB) ( 963 )   Save
    A large microwave Type Ⅳ radio burst associated with CMEwas observed withPhoenix I Corona Radio Spectrometer of Yunnan Observatory on December 16,1988 as an accompanying event. atom 0826 to 0941 UT, a long period oscillation of 12.1 minutes occurred among five main peaks on three wave bands. Ashort periodoscillation of 1.2 minutes appeared among six subpeaks on first main peak. Onthe basis of Beijing Huairou magnetogram, the concerned physical parameters ofburst source region are calculated, e.g. brightness temperature, electron power-lawdistribution, etc. The short period oscillation calculated with the slow wave modelconforms to the observational period. This large Type IVμ burst, CME and otheraccompanying phenomena are all interpreted preliminarily.
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    NUMERICAL SIMULATION OF CORONAL MASS EJECTIONS BETWEEN TWO CORONAL STREAMERS
    LI Fenglin;JIANG Xinying;XIONG Donghui
    1999, 19 (4):  308-314.  doi: 10.11728/cjss1999.04.308
    Abstract ( 1556 )   PDF (442KB) ( 1061 )   Save
    In this paper, simulations of coronal mass ejections between two coronal streamers are conducted based on a two-dimensional MHD equation set. In order tore-appear the general characteristics of the CME, the simulation adds the closemagnetic field caused by a cycle current and the disturbing-pressure. The resultsshow: The disturbance can lead to an obvious plasma loop structure with highdensity and a low-density region behind the outer loop. They produce both radialand transverse expansion in different degree. The results apporoximately conformto the main characteristics of No.80127 CME event.
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    THE CALCULATION OF LOWER IONOSPHERIC TEC ENHANCEMENT DURING INITIAL FLARE BURST USING HF DOPPLER RECORDS
    ZHANG Donghe;XIAO Zuo;GAO Yufen;WANG Jialong
    1999, 19 (4):  315-320.  doi: 10.11728/cjss1999.04.315
    Abstract ( 1683 )   PDF (420KB) ( 1173 )   Save
    By analyzing the change of electron density in different ionospheric regionsduring flare bursts, a new method is introduced, by which the TEC enhancement inthe lower ionosphere during the initial phase of a flare burst can be calculated using HF Doppler records. Some TEC enhancements caused by flare bursts from Marchto June in 1990 are calculated using this method. The results of TECenhancementare compared with the maximum fluxes of the soft X--ray of the corresponding flares.The correlation between the calculated TEC enhancement and maximum fluxes ofthe soft X-ray radiation of solar flares are fairly good in general, except very intenseflares.
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    EFFECTS OF NONLINEARITY ON THE CHARACTERISTICS OF GRAVITY WAVES
    ZHANG Shaodong;YI Fan;WANG Jingfang
    1999, 19 (4):  321-326.  doi: 10.11728/cjss1999.04.321
    Abstract ( 2115 )   PDF (398KB) ( 1289 )   Save
    By analyzing the numerical results of nonlinear propagation of a Gaussiangravity-wave-packet in isothermal atmosphere, the effects of nonlinearity on thecharacteristics of gravity waves are studied quantitatively. The analyses show that:during the nonlinear propagation of gravity-wave--packet, affected by nonlinearity,the vertical wavelength show a decrease and the mean flow show clear enhancement.On the other hand, though there exists nonlinear effects, the linear dispersion relation and polarization are still feasible, which indicates that the dispersion relationand polarization based on linear gravity wave theory can be applied extensively innonlinear cases.
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    MEDIUM-SCALE GUIDED GRAVITY WAVESSUPPORTED BY THE BACKGROUND WINDS
    LIANG Jun;YUAN Hong;WAN Weixing
    1999, 19 (4):  327-333.  doi: 10.11728/cjss1999.04.327
    Abstract ( 1920 )   PDF (320KB) ( 969 )   Save
    A new propagation mechanism of guided gravity waves supported by the upper atmospheric wind is suggested in this paper. The numerical results show that,the existence of strong upper atmospheric winds make possible the long-distancemedium-scale guided gravity waves. The observed superior distributions of horizontal phase velocity at Millstone Hill are just correspond to those modes with longerattenuation distances. When the period of wave is smaller, the attenuation distanceof the guided wave strongly depends on the magnitude of wind speed along the antipropagation direction. The stronger the wind on the anti--propagation direction,the longer the attenuation distance, hence the more easily to be observed. Whenthe period becomes larger or the wind speed along the anti--propagation direction issmall, the ducting mechanism vanishes indeed. The above studies are in good accordance with the observation result at Millstone Hill, and give another interpretablepropagation mechanism of observed medium-scale gravity waves at mid--latitude.
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    THE CHARACTERISTICS OF WINDS AT HEIGHT OF 20-80km IN THE CHINESE AREA
    MA Ruiping;LIAO Huaizhe
    1999, 19 (4):  334-341.  doi: 10.11728/cjss1999.04.334
    Abstract ( 2314 )   PDF (556KB) ( 1641 )   Save
    Some characteristics of winds at height of 20-80 km in the Chinese area areobtained using the Nimbus-7 SAMS temperature data from 1979 to 1981 by thegeostrophic balance thermal wind equations. It is shown that the winds from satellite are coincident roughly with the winds from Chinese rocket measurements andthe derivation of winds with the satellite temperature data is effective in obtainingclimate characteristics of winds at height of 20--80 km in Chinese area. These results show the difference between the zonal mean winds above China with the zonalmean wind of CIRA-1986 is obvious. The longitudinal difference of the winds atheight 20--80km over China is also evident. The effect on the middle atmospherewinds by topography of this area can not be disregarded. The meridional wind andvariations of winds over China is discussed.
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    A SOLAR MICROWAVE BURST SPECTROMETER
    LIU Yuying;FU Qijun
    1999, 19 (4):  342-348.  doi: 10.11728/cjss1999.04.342
    Abstract ( 1861 )   PDF (526KB) ( 658 )   Save
    In the paper the solar radio specrtometer in 1.0—2.0GHz and 2.6—3.8GHz which are working and the 5.2—7.6 GHz spectrometer which will come into operation in 1999, are introduced. They are the key observation facilities of solar physicscommunity in China for the coming 23rd solar active maximum years. 171 and 146 bursts of different types in 1.0—2.0 GHz and 2.6—3.8 GHz, respectively, with awealth of fine structure in time and frequency has been registered. The solar radiobursts at different frequencies reflect the evolving processes of solar flares in timeand heigh, and provide useful data for the study of solar flares.
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    ATTITUDE STABILITY OF SOLAR WINGS ON SPACECRAFT WITH A FLEXIBLE SHAFT IN GRAVITATIONAL FIELD
    GE Xinsheng;LIU Yanzhu
    1999, 19 (4):  349-353.  doi: 10.11728/cjss1999.04.349
    Abstract ( 1963 )   PDF (317KB) ( 963 )   Save
    The attitude motion of solar wings on spacecraft with a flexible shaft in gravitational field is discussed in this paper. The generalized potential energy of spacecraftsystem is derived. The stability of relative equilibrium of solar wings on spacecraftwith a flexible shaft in the orbital plane is determined by use Liapunov's directmethod. Asufficient condition of stability on spacecraft is obtained, and the influence of the torsion stiffness of a flexible shaft and the mass geometry of solar wingson the attitude stability is analysed.
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    FAST LOCATING ONBOARD FAULT OF SMALL SATELLITES USING FUZZY CLUSTERING ALGORITHMS
    YANG Jiajun;CAO Xibin;MA Xingrui
    1999, 19 (4):  354-361.  doi: 10.11728/cjss1999.04.354
    Abstract ( 2176 )   PDF (498KB) ( 978 )   Save
    Considering the complexity of small satellites, large number of monitoringpoints and the inherent fuzziness and uncertainty of measuring information, a simplified FCM algorithm is presented in this paper to fast locate on-board fault. As on of the applications, this paper also describes the onboard fault fast locating systemof SMMS, which is a small satellite of Research institute of Satellite Engineeringand Technology of Harbin institute of Technology and will be launched in 2000.
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    A COMPENSATION OBSERVER METHOD FOR THE IMPROVEMENT OF PERFORMANCE OF LOW- SPEED REACTION WHEEL
    WANG Bingquan;LI Ying;YANG Di
    1999, 19 (4):  362-367.  doi: 10.11728/cjss1999.04.362
    Abstract ( 1869 )   PDF (382KB) ( 1388 )   Save
    The dynamic equation of the low-speed reaction wheel used to stabilize a satellite's three-axis attitude is put forward on the base of Dahl friction model, andaccording to this the phenomenon that the reaction wheel's speed crossing zero disturbs satellites attitude is analyzed. Anonlinear observer is used to estimate thefriction torque in order to compensate it. Simulation results prove that this methodcan compensate the reaction wheel low-speed friction, and improve attitude pointingaccuracy and stability.
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    HUGONIOT PARAMETERS OF SEVERAL MAIN TYPES OF METEORITES
    DAI Chengda;TAN Hua;WANG Daode;MAO Yanhua
    1999, 19 (4):  368-374.  doi: 10.11728/cjss1999.04.368
    Abstract ( 2030 )   PDF (481KB) ( 951 )   Save
    Hugoniot parameters of iron meteorite, EHand ELenstatite chondrites, H-,L-, LL-group ordinary chondrites are determined by using the volume additivitymethod based on their model chemical or mineral compositions. The Hugoniotparameters of several main types of meteorites are evaluated as following: iron meteorite, ρ0 = 7.78 g/cm3, c0 = 4.342 km/s, s = 0.489 (P <30GPa); c0 = 3.610km/s,s = 1.623 (30 GPa ≤ P ≤ 270 GPa); EH-group enstatite chondrite, P0 = 3.8g/cm3,c0 = 3.978km/s, s = 1.422 (P ≤50GPa); c0 = 3.377km/s, s = l.552 (60GPa ≤ P ≤120 GPa); EL-group enstatite chondrite, ρ0 = 3.6g/cm3, c0 = 4.821 km/s, s = l.115(P ≤ 50GPa); c0 = 3.644km/s, s = 1.552 (60GPa ≤ P ≤ 120GPa); H-group ordinary chondrite, ρ0= 3.5 g/cm3, c0 = 4.459km/s, s = 1.143 (P ≤ 120GPa); L-groupordinary chondrite, p0 = 3.2g/cm3, c0 = 4.418 km/s, s = 1.145 (P ≤ 120GPa); LL group ordinary chondrite, ρ0 = 3.0 g/cm3, c0 = 4.012 km/s, s = 1.194 (P ≤ 120 GPa).The above calculated Hugoniot parameters are in agreement with experimentallymeasured data reported for the same types of meteorites. In addition, the residual temperature (corresponding to shock metamorphism temperature) of ordinarychondrites (H-, L-, LL-group) are estimated, and the temperature ranges of shockstages (S1-S6(7)) of ordinary chondrites are scaled. They are: S1 (0-5 GPa):<300 K; S2 (5-10 GPa): <300 K; S3 (10-20GPa): 300We400K; S4 (20-40 GPa):350 (±50)-700 (±100)K; S5 (40-70GPa): 700 (±100)-1400 (±250)K; S6 (70-100 GPa): 1400 (±300)-2100 (±300)K; S7 (>100 GPa): >2100 (±300)K. This temperature calibration are based on the assumption that the initial temperature ofordinary chondrites suffered shock loading is around 173 K.
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    PERFORMANCE STUDY OF THIN FILMS FOR ATOMIC OXYGEN AND RADIATION ENVIRONMENT PROTECTION IN SPACE
    LU Yusun;FENG Yudong;ZHAI Houming;WANG Yi
    1999, 19 (4):  375-380.  doi: 10.11728/cjss1999.04.375
    Abstract ( 2042 )   PDF (448KB) ( 963 )   Save
    The metal oxide films are widely use as thermal control materials on satellitesurface against static electricity accumulation. It is further found in the experimentthat these films have also the excellent ability for plasma oxygen and radiationprotection in the space environment. The ability depends on the deposition methodsand process parameters. The test results indicate that the mass loss of the sampleswith sputtered TOfilm is much less than that of the samples of evaporated ITO film, and the mass loss of the samples with evaporated ITO film is less than thatof the samples uncoated too. After plasma oxygen action, electron radiation andultraviolet radiation, the variation of the sheet resistance and the solar absorptanceof To film is also much less than that of ITOfilm. The AFM analysis proves thatthere is a large difference of the film's stability and compactness by the differentpreparing method and processes.
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