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21.
The first China-US joint dust field experiment was carried out by Lanzhou University, Chinese Academy of Sciences, China Meteorological
Administration, and University of Maryland, the Department of Energy (DOE), USA, from April to June, 2008. The
observation sites are located at Zhangye National Climatological Observatory, Semi-Arid Climate and Environment Observatory
of Lanzhou University (SACOL), and Jingtai with the Mobile Facilities of SACOL. The measurements of Particle Soot Absorption
Photometer and TSI Integrating Nephelometer are used to analyze the aerosol absorption and scattering characteristics over
Zhangye. The results are: the aerosol absorption, total scattering, and backscattering coefficients present similar diurnal variation
trends with their bi-peaks at 08:00 and 22:00, and they are generally higher in nighttime than in daytime. Their monthly average
coefficient is the highest in April, and then drops in succession in May and June. Frequency analysis of aerosol single scattering
albedo (SSA) shows that the magnitudes of SSA at 450, 550, and 700 nm are mainly within 0.7–0.9. The maximum frequency of
SSA at 450 and 700 nm distribute at 0.8, and at 0.85 for 550 nm. The averages of SSA at 450, 550, and 700 nm are 0.72, 0.75, and
0.68, respectively. 相似文献
22.
Zhi-E Liu Shao-Lan Bi Wu-Ming Yang Tan-Da Li Kang Liu Zhi-Jia Tian Zhi-Shuai Ge Jie Yu 《天文和天体物理学研究(英文版)》2014,(6):683-692
Oscillations of the solar-like star HD 49933 have been thoroughly observed by CoRot. Two dozen frequency shifts, which are closely related to the change in magnetic activity, have been measured. To explore the effects of magnetic activity on frequency shifts, we calculate frequency shifts for the radial and l = 1 p-modes of HD 49933 with the general variational method, which evaluates the shifts using a spatial integral of the product of a kernel and some sources. The theoretical frequency shifts reproduce the observation well. The magnitudes and positions of the sources are determined according to a χ2criterion. We predict the source that contributes to both the l = 0 and l = 1 modes is located 0.48- 0.62 Mm below the surface of the star. In addition, based on the assumption that A0is proportional to the change in the MgII activity index ?iMgII, we obtain that the change in MgII index between the minimum and maximum of the cycle during the period of HD 49933 is about 0.665.The magnitude of the frequency shifts compared to the Sun already demonstrates that HD 49933 is much more active than the Sun, which is further confirmed in this paper. Furthermore, our calculation of the frequency shifts for l = 1 modes indicates the variation of turbulent velocity in the stellar convective zone may be an important source for the l = 1 shifts. 相似文献
23.
The observational results of the Nobeyama 45-m SiO maser survey and the Arecibo 305-m OH maser survey are assembled for an analysis of the distribution and kinematics of late-type stars in the Galactic plane.It is found that neither SiO maser stars nor OH maser stars show any concentration to the spiral arms,which imply that they do not belong to the arm population and quite possibly they are low-mass stars in late stage of evolution.A rotational curve is also derived for these objects and a few features which may be real are discussed and compared with those derived from planetary nebulae and AGB stars. 相似文献
24.
浙江晚泥盆世五通组中的楔叶类（Sphenophyllales）化石 总被引：2，自引：0，他引：2
本描述了产自浙江长兴泗安五通组中的几种楔叶类化石：Eviostachya hoegii(Stockmans)、Arch-aeocalamites sp.、Hamatophyton verticillatum Gu et Zhi、Sphenophyllum pseudotenerrimum(Sze)和Sphenophyllostachys sp.等。特别是Eviostachya hoegii的发现，为浙江晚泥盆世地层进行国际性对比，提供了新的依据。 相似文献
25.
Bi Xunqiang 《大气科学进展》1997,14(4):569-572
ＰａｒａｌｅｌＣｏｍｐｕｔｉｎｇｏｆａＣｌｉｍａｔｅＭｏｄｅｌｏｎｔｈｅＤａｗｎ１０００ｂｙＤｏｍａｉｎＤｅｃｏｍｐｏｓｉｔｉｏｎＭｅｔｈｏｄ①ＢｉＸｕｎｑｉａｎｇ（毕训强）ＩｎｓｔｉｔｕｔｅｏｆＡｔｍｏｓｐｈｅｒｉｃＰｈｙｓｉｃｓ，ＣｈｉｎｅｓｅＡ... 相似文献
26.
Volcanic eruption is an important external forcing factor of climate change on time scale frommonth to hundred years.In this paper,the climatic effect of the last large historical eruption ofTianchi volcano,which happened in 1229 AD,has been investigated with a two-dimensionalenergy balance model.Taking Mt.Pinatubo volcano and Changbai Mountain-Tianchi volcano forexample,the numerical simulation on time scale from months to years indicates that such largeeruptions may have significant impacts on global climate.Based on the simulation results,it issuggested that the last large eruption of Tianchi volcano should be responsible for the abruptclimate change event,which began in the period from 1230 to 1260 AD. 相似文献
27.
A numerical experiment has been carried out with IAP (Institute of Atmospheric Physics) 9-layer general circulation model
to investigate the influence of the Antarctic Ozone Hole on the global climate. The results show that the changes of total
amount of ozone over higher latitude and polar region of the Southern Hemisphere affect not only the climate in the Southern
Hemisphere, but also that in the Northern Hemisphere significantly. In the next spring, although the total amount of ozone
over Antarctica has returned to the normal value, the influences of Ozone Hole still exist.
Suppported by LASG and the National Key Project of Fundamental Research “Climate Dynamics and Climate Prediction Theory.≓ 相似文献
28.
The Spanish Mackerel Scomberomorus niphonius (C. et V.), a fish of the upper layer lukewarm water quick in movement, migrates over long distances in shoals. With the development of the nylon drift net the annual catch of such fish has increased rapidly. Since 相似文献
29.
THE TEMPORAL AND SPATIAL PATTERNS OF ENVIRONMENTAL RISK EVENTS IN THE PAST 30 YEARS IN SHENYANG CITY
1.IntroductionEnvironmentalrisk'isamajorenvirotunedlthreattothesustainabilityoftheropon.ItsanalysishasbecomeafOcusofenvironmentalstudyinthepastl0years.0win8torapideconothecdeveloPmentinChina,manykindsOfpotatialriskshavegreatlyhamPeredtheroponalsustainable… 相似文献
30.