Past Experience and the Present in the History of the Man and Nature Relationship in the Great Steppe

The considerable part of the Northern Asia is occupied with the steppe and forest-steppe landscapes stretched by a wide strip from Caspian Sea to mountains of Big Khingan.Archeologists claim, that from here on the Bering Bridge after a glacial age ancestors of American Indian tribes have left to the North America. In the Baikal Lake basin we find settlements of ancient Huns, subdued the Eastern and Western Europe in the beginning of last millennium.     

Magnetic activity of the spotted dwarf AP149 in the α Persei open cluster

The simultaneous photometric and spectroscopic observations of the spotted G dwarf AP149 in the young open cluster α Persei are analyzed here.We reconstruct the observed light curves with a two-starspot model by means of a light curve modeling technique,and find that the active regions shift oppositely along longitude on a time scale of one day.Combining with the observational data obtained by other groups,we discuss the evolution of spotted regions in the photosphere,and find that its starspots evolve not ...     

Investigation of forest-resources potential of Selenge River Basin on transboundary territory of the Republic of Buryatia and Mongolia

The author studied the issues of the present-day status of forest resources and forest management of the Selenge River Basin on the transboundary territory of the Buryat Republic and Mongolia. It is necessary to establish a good policy for wood cutting of the main and secondary use and reforestation.     

NECT样带1984～1996土地利用变化分析

在分区选择典型样点的基础上,从土地利用结构类型和土地利用强度等方面对中国东北带（ＮＥＣＴ）近年来的土地利用变化进行分析,揭示出样带上土地利用发生变化较剧烈的区域为农牧交错带,变化的原因主要是人类活动强度的增加。此结论对样带上的生态敏感区域制定土地利用开发与管理下策应具有意义。     

Densification and grain coarsening of melting snow

1　IntroductionSnowdensificationiscriticalforcalculationsinengineering glaciology,snowavalancheforecasting ,springflooding,andotherpracticalaspects.Itisalsoimportantforinterpretingicecoredataincludingthosetakenfromratherwarmsiteswheresurfacelay ersexperiencemelting ,sinceitwouldaffectthechangeofannuallayerthicknesswithtime.Whileextensivestudies(e.g .AndersonandBenson 1 963 ;Bader1 960 ,1 962 ;Koji ma 1 95 4,1 95 5 ,1 95 6,1 95 7,1 95 8,1 95 9,1 964;Keeler 1 967;Gow 1 975 ;MaenoandE binuma 1…     

中纬度地区混合云中稳定同位素分馏的数学模拟—以乌鲁木齐降水为例(英)

介绍的数学模型考虑了混合云中液、固态共存时以及冰面过饱和环境下稳定同位素的动力分馏效应。利用该数学模型,模拟了不同冷却条件下稳定同位素的温度效应。在相同的湿度条件下,湿绝热冷却过程中δ18O随温度的变化率小于等压冷却过程。冰面过饱和比Si的增大意味着动力分馏效应的增大。与平衡态相比,它的作用使得稳定同位素的综合分馏系数减小,从而使得降水中δ18O随温度的变化趋缓。模拟显示,湿绝热冷却过程中大气水线(MWL:=bδ18o+d)的斜率b和常数d均大于等压冷却过程。全球大气水线位于湿绝热冷却过程和等压冷却过程条件下分别模拟的两条大气水线之间。b和d的大小与Si呈正比。Si愈大,动力分馏效应愈强,b和d也愈大。反之亦然。然而,b和d的大小对云中含水量的变化具有低的敏感性。利用动力分馏模式模拟了乌鲁木齐降水中稳定同位素的变化。模拟的稳定同位素比率-温度以及δD-δ18O曲线分别与乌鲁木齐实测的稳定同位素比率-温度同归线以及大气水线有非常好的一致性。     

Chemical Characteristics of Snow-Firn Pack in Altai Mountains and Its Environmental Significance

In order to study the chemical characteristics of snow-firn pack in Altai Mountains and its environmental significance, a 1.5-m deep snow-firn pack was dug in the accumulation zone (3 300 m a.s.l.) of the Kanas Glacier in August 2009. A total of 15 samples were analyzed for major ions. Results show that the concentrations of major ions in the snow-firn pack are NH4+>SO42->Ca2+>NO3-> Na+>Cl->K+>Mg2+. NH4+ is the dominant cation with a medium value of 4.7 ueq·L-1, accounting for 39.8% of the total cations, an...     

Speleogenesis of Selected Caves beneath the Lunan Shilin and Caves of Fenglin Karst in Qiubei, Yunnan

Yunnan is famous for its attractive karst landscapes especially shilins, fengcong and fenglin. The development of caves beneath the shilins in the vicinity of Lunan is closely connected with the formation of shilins. Most of the waters percolating through shilins run through the caves beneath them and are responsible for their formation. The study of cave speleogenesis deepens knowledge about both the development of shilins and karst structure. In the vicinity of the Lunan Shilin, speleological, morphological and structural geological studies of four karst caves have been accomplished. At Puzhehei, Qiubei, which is characterised by numerous fenglin, fengcong and caves, speleological and morphological studies have been performed. Cave sediments for paleomagnetic analyses have been taken from all studied areas (samples CH 1-9). Karst caves in SE Yunnan are probably much older than the age of the cave sediments (<780,000 years B.P.). The studied areas are located in the vicinity of the Xiaojiang fault (N-S