Letter to the Editor: The collisional broadening of carbon radio recombination lines     

N.I. Rovenskaya 《Astrophysics and Space Science》2004,293(3):355-362

The density matrix equations of highly excited carbon are analytically solved as functions of line number and temperature. Allowing for the series of the impact approximation theory and quadrupole interaction potential, the line widths are found with the theoretical error less than 0.06 in the range of temperatures T _e = 25 − 100 K. To determine the medium temperature and density by using the experimental values of line widths, the Doppler, radiational and impact broadening are calculated for the lines with the principal quantum numbers n > 300. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Modelling of aspherical nebulae – I. A quick pseudo-3D photoionization code     

C. Morisset  G. Stasi&#;ska  M. Peña 《Monthly notices of the Royal Astronomical Society》2005,360(2):499-508

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Movements of the Western Pacific Warm Pool Centroid and Their Relationship to Sea Surface Temperature Changes in Nino Regions     

FANG Mingqiang Ocean Remote Sensing Institute  Ocean University of China  Qingdao  P.R.China 《中国海洋大学学报(英文版)》2005,4(2)

By using monthly historical sea surface temperature (SST) data for the years from 1950 to 2000, the Western Pacific Warm Pool (WPWP) climatology and anomalies are studied in this paper. The analysis of WPWP centroid (WPWPC) movement anomalies and the Nino-3 region SST anomalies( SSTA) seems to reveal a close, linear relation between the zonal WPWPC and Nino-3 region SSTA, which suggests that a 9' anomaly of the zonal displacement from the climatological position of the WPWPC corresponds to about a 1 ℃ anomaly in the Nino-3 region area-mean SST. This study connects the WPWPC zonal displacement with the Nino-3 SSTA, and it may be helpful in better understanding the fact that the WPWP eastward extension is conducive to the Nino-3 region SST increase during an El Nino-Southern Oscillation (ENSO) event.  相似文献   

河南省电子政务空间信息服务系统建设与典型应用   总被引：2，自引：0，他引：2  

邓跃明 《地理信息世界》2005,3(3):18-20,25

介绍了河南省电子政务空间信息服务系统的项目背景、系统总体设计，论述了数据处理与集成建库所涉及的一些关键技术，并以中原城市群空间信息服务系统为典型应用，作了进一步的探讨。  相似文献   

Stability Regions and Quasi-Periodic Motion in the Vicinity of Triangular Equilibrium Points     

O. Ragos  K. E. Papadakis  C. G. Zagouras 《Celestial Mechanics and Dynamical Astronomy》1997,67(4):251-274

The regions of quasi-periodic motion around non-symmetric periodic orbits in the vicinity of the triangular equilibrium points are studied numerically. First, for a value of the mass parameter less than Routh's critical value, the stability regions determined by quasi-periodic motion are examined around the existing families of short (L^s ₄) and long (L^l ₄) period solutions. Then, for two values of μ greater than the Routh value, the unified family L^sl ₄, to which, in these cases, L^s ₄ and L^l ₄ merge, is considered. It is found that such regions surround in general the linearly stable segments of the corresponding families and become smaller as the mass ratio increases. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Self-similar shocks in polytropic gas flows around star-forming regions     

Yu-Qing Lou  Yang Gao 《Monthly notices of the Royal Astronomical Society》2006,373(4):1610-1618

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The generation of ionization-shock front oscillations by a variable radiation flux     

K. V. Krasnobaev 《Astronomy Letters》2002,28(9):594-600

The effect of a time-varying radiation flux incident on an ionization front on the generation of ionization-shock front oscillations in the interstellar medium is analyzed analytically and numerically. We take into account both variations in the flux of ionizing radiation directly from the source that produces the ionization front and the absorption of energetic photons by the post-front plasma. Based on our calculations, we show that the time dependence of the radiation flux can be an additional factor (apart from small inhomogeneities in the interstellar medium) that contributes to the amplification of oscillations and to the kinetic energy input to the observed turbulent motions in H II regions.  相似文献   

The electron temperature and density in interstellar medium by using carbon radio recombination line observations     

N.I. Rovenskaya 《Astrophysics and Space Science》2004,291(2):113-122

The intensities of carbon radio recombination lines (RRL’s) are definedallowing for the effect of dielectronic-like recombination. The rate ofdielectronic-like recombination is calculated as functions of line number,electron density and temperature accurate to 0.05. Following from the balanceequation solutions for populations, the RRL intensities are analytically foundby the method of successive approximations to an accuracy of 0.15. Theobservations of carbon RRL’s are analyzed toward Cassiopeia A. The averageelectron temperature, density, expanded CII region lengths and inaccuraciesare found with the experimental values of RRL widths and intensities.  相似文献   

Extreme vacuum ultraviolet solar spectra obtained during the SPIRIT experiment aboard CORONAS-F: A catalog of lines in the range 280–330 Å     

I. A. Zhitnik  S. V. Kuzin  A. M. Urnov  I. L. Beigman  S. A. Bozhenkov  I. Yu. Tolstikhina 《Astronomy Letters》2005,31(1):37-56

We present a catalog of 100 lines in the wavelength range 280–330 Å detected by the RES-C spectroheliograph in solar active regions and flares during the SPIRIT experiment aboard the CORONAS-F orbital station. We identified 54 lines. The line intensities recorded during the X3.4 (GOES) solar flare of December 28, 2001, are given. The data reduction procedure is discussed.  相似文献   

对太阳第21周最强烈活动区的分析     

李维宝  王洪照 《天文研究与技术》1997,(1)

太阳第２１周实测到３９８６个活动区，以黑子面积、Ｘ射线耀斑指数、１０．７ｃｍ射电爆发及质子事件等四项指数，从中综合评估出ＡＲ３８０４、ＡＲ４４７４等１６个最强烈活动区。与２２周比较，两周都有在时空分布的相对集中性特征。但２１周集中在４个时段，不如２２周在２个时段集中；２１周出现的５个热点，只有南半球在经度８５°前后的热点，与２２周３个热点之一相似；２１周的整体活动水平略低，在Ｘ射线和质子事件两方面尤为显著低于２２周  相似文献