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361.
362.
四万年来青藏高原的气候变迁 总被引:83,自引:10,他引:83
内陆湖泊,特别是那些大型的淡水湖和盐湖,在漫长的演变历史长河中,对气候环境的反映是相当敏感的。巨厚的沉积物,记录了古气候变迁的丰富信息。盐湖的研究表明,40000年来的重大气候事件,在世界屋脊——青藏高原内部同样有明显的反映。 相似文献
363.
BOUNDARY LAYER GROWTH AND LAPSE RATE CHANGES DETERMINED BY LIDAR AND SURFACE HEAT FLUX IN SOFIA* 下载免费PDF全文
In this study the results from a boundary layer experiment,conducted in autumn 1991 over a flat,build-up urban area in Southeast Sofia,together with some models for mixed layer growth rates are used to investigate the layered structure of the vertical atmospheric stability distribution in the Sofia Valley.Lidar measurements of aerosol layer heights and morning boundary layer development are combined with surface eddy correlation measurements of kinematic heat and moisture fluxes,profiles of temperature and humidity,wind speed and wind direction.A diagnostic method is presented for determining vertical lapse rates using surface meteorological measurements and lidar returns observed during the transition from nighttime stable stratification to daytime convective boundary layer after the sunrise. 相似文献
364.
Tobler W Deichmann U Gottsegen J Maloy K 《International journal of population geography : IJPG》1997,3(3):203-225
"We report on a project that converted subnational population data to a raster of cells on the earth. We note that studies using satellites as collection devices yield results indexed by latitude and longitude. Thus it makes sense to assemble the terrestrial arrangement of people in a compatible manner. This alternative is explored here, using latitude/longitude quadrilaterals as bins for population information.... The results to date of putting world boundary coordinates together with estimates of the number of people are described. The estimated 1994 population of 219 countries, subdivided into 19,032 polygons, has been assigned to over six million five minute by five minute quadrilaterals covering the world." 相似文献
365.
The geography of highly skilled international migration 总被引:1,自引:0,他引:1
"The present paper provides a research review of recent literature on international migration by the highly skilled. Its principal aim is to identify the themes which are being discussed, and suggest where research into the subject might best proceed.... [The authors outline] the two most important perspectives in extant research, economic and socio-cultural, [and review] what is known about the geography of migration by the highly skilled.... The paper proposes...a reconceptualisation of migration by the highly skilled as one element in the international movement of expertise." 相似文献
366.
Sanjaya Gurung Bikas C. Bhattarai Rijan B. Kayasth Dorothea Stumm Sharad P. Joshi Pradeep K. Mool 《寒旱区科学》2016,8(4):311-318
Although Himalayan glaciers are of particular interest in terms of future water supplies, regional climate changes, and sea-level rises, little is known about them due to lack of reliable and consistent data. There is a need for monitoring these glaciers to bridge this knowledge gap and to provide field measurements necessary to calibrate and validate the results from different remote sensing operations. Therefore, glaciological observations have been carried out by the Cryosphere Monitoring Project(CMP) since September 2011 on Rikha Samba Glacier in Hidden valley, Mustang district in western Nepal in order to study its annual mass balance. This paper presents the first results of that study. There are 10 glaciers in Hidden Valley, named G1, G2, G3, up to G10. Of these, G5 is the Rikha Samba Glacier, which has the largest area(5.37 km2) in this valley and the highest and lowest altitudes(6,476 and 5,392 m a.s.l., respectively). The glacier mass balance discussed in this paper was calculated using the glaciological method and the equilibrium line altitude(ELA). The glacier showed a negative annual point mass balance along the longitudinal profile of its lower part from September 10, 2011 to October 3, 2012. Stake measurements from October 4, 2012 to September 30, 2013 indicated a negative areal average of annual mass balance-0.088±0.019 m w.e. for the whole glacier. Based on these observations, the ELA of the Rikha Samba Glacier is estimated at 5,800 m a.s.l. in 2013. This negative balance may be due to rising air temperatures in the region, which have been incrementally rising since 1980 accompanied by little or no significant increase in precipitation in that period. The negative mass balance confirms the general shrinking trend of the glacier. 相似文献
367.
Rajesh K. Srivastav Ulf S?derlun Richard E. Ernst Sisir K. Mondal Amiya K. Samal 《《地质学报》英文版》2016,90(Z1):17-18
正The Singhbhum craton of the eastern India consists of the Singhbhum Granite Complex(SGC)and the Chotanagpur Gneissic Complex(CGC)separated by the Singhbhum Mobile Belt(SMB).The CGC is intruded by Mesoproterozoic as well as Cretaceous mafic dykes;in 相似文献
368.
正The Moyar-Bhavani Shear Zone(MBSZ)of the South Indian Granulite Terrain(SIGT),a complex continental block formed by the accretion of various crustal units during the Archaean to Neoproterozoic,bear evidences of 相似文献
369.
正Occurrence of mafic dykes in Himalaya has been intriguing and debated since long because of its difficulty to ascent and emplacement through a thickened crust.Mafic dykes in Kumaun Lesser Himalaya(KLH)of central Indian 相似文献
370.