New Aspects of Extragalactic Globular Clusters     

Myung Gyoon Lee 《天文研究与技术》1999,(Z1)

1　ＩｎｔｒｏｄｕｃｔｉｏｎＧｌｏｂｕｌａｒｃｌｕｓｔｅｒｓａｒｅｃｏｎｓｉｄｅｒｅｄｔｏｂｅｔｈｅｏｌｄｅｓｔｓｔｅｌｌａｒｓｙｓｔｅｍｓｉｎｇａｌａｘｉｅｓｓｏｔｈａｔｔｈｅｙｋｅｅｐａｆｏｓｓｉｌｒｅｃｏｒｄｏｆｅａｒｌｙｈｉｓｔｏｒｙｏｆｇａｌａｘｉｅｓ .Ｔｈｅｙａｒｅｓｏｂｒｉｇｈｔｔｈａｔｔｈｅｙｃａｎｂｅｏｂｓｅｒｖｅｄｅｖｅｎｉｎｄｉｓ ｔａｎｔｇａｌａｘｉｅｓ,ａｎｄｔｈｅｙａｒｅａｂｕｎｄａｎｔｉｎｇａｌａｘｉｅｓ,ｅｓｐｅｃｉａｌｌｙｉｎｇｉａｎｔｇａｌａｘｉｅｓｗｈｉｃｈｈａ…  相似文献   

安大略州格林維尔区西港整合深成岩体的构造     

H.  R.  外尼-爱德华 《地质力学学报》1994,(1):275-282

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EXPERIMENTAL DESIGN IN CHEMOMETRICS     

STANLEY N.DEMING JOHN A.PALASOTA JOSEPHINE M.PALASOTA Department of Chemistry University of Houston  Calhoun Ro  Houston  TX -  U.S.A. 《地理学报(英文版)》1991,(3)

Chemometrics is defined as the application of mathematical and statistical methods to chemical systems.Systems theory is seen to be useful for organizing and categorizing the inputs to and outputs fromchemical systems.Advances in measurement science in the 1950s and 1960s,particularly in analyticalchemistry,created a need for a multivariate approach to data analysis.Early chemometrics emphasizedthe use of structure-finding methods for existing data sets.In many instances,data sets can be obtainedfrom designed experiments.Such data sets are more likely to contain the desired information and the datacan usually be acquired at less cost.Renewed interest in statistical process control will provide many new,more robust data sets in the future.  相似文献   

征订启事     

本刊年征订工作业已开始。本刊委托天津市全国非邮发报刊《联订服务部》办理订阅事宜。定价每册.元  全年订价.元。凡需订阅者请将订刊款通过邮局或银行汇款至下列地址即可：　　邮政编码：　　地址：天津市大寺泉集北里别墅号户头全称：天津市河西区联合征订服务部帐 号：-　　开户银行：工商行天津市尖山分理处电 话： 《天文学进展》2000,18(3):191

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RS AND GIS-BASED FOREST FIRE RISK ZONE MAPPING IN DA HINGGAN MOUNTAINS     

YIN Hai-wei  KONG Fan-hua    LI Xiu-zhen 《中国地理科学(英文版)》2004,14(3):251-257

1INTRODUCTIONForests are one of the major natural resources that per-form important environmental and recreational func-tions (COSTANZA and GROOT, 1997). It is well known that forests can absorb atmospheric carbon, maintain a certain degree of humidity in atmosphere, regulate rainfall, moderate temperature, and restrain soil erosion, etc. (AURELIA, 2003). So, the health of a forest in any given area is a very important indicator of the ecological conditions. But fire is the great…  相似文献   

The Effects of Land Uses on Purplish Soil Erosion in Hilly Area of Sichuan Province, China     

LIU Gangcai    ZHANG Jianhui  TIAN Guanglong  WEI Chaofu College of Resources  Environment  Southwest Agriculture University  Chongqing  China Institute of Mountain Hazard  Environment  Chinese Academy of Science & Water Resources Ministry  P. O. Box  Chengdu  Sichuan  China Research  Development Department  Metropolitan Water Reclamation District of Greater Chicago  W. Pershing Road  Cicero  IL -  USA 《山地科学学报》2005,2(1):68-75

1 Introduction Food grain productivity of dry land per capitahas declined significantly during the past fewdecades (Parr et al. 1990). Bowman et al. (1990)and Blaikie (1985) indicated that the greatest lossin productivity comes from soil loss, withsecondary effects from loss of nutrients due toreduced organic matter and increased soil bulkdensity. Soil erosion has major ecological andeconomic consequences in densely populatedChina, particularly, in a large agriculture province,Sichuan…  相似文献   

The Effect of Tide on the Global Climate Change   总被引：1，自引：0，他引：1  

YANG Xuexiang  CHEN Zhen  CHEN Dianyou 《东北亚地学研究》2002,(1)

The differential rotation between the solid and fluid spheres caused by tidal force could explain the 1500 to 1800 - year cycle of the worlds temperature. Strong tide increases the vertical and horizontal mixing of water in the oceans,dra-wing the cold Pacific water from the depths to the surface and the warm water from the west to the east, where it cools or warms the atmosphere above, absorbs or releases CO2 to decrease or increase greenhouse effect and to make La Nina or El Nino occur in the global. The moons declination and obliquity of the ecliptic affect the tidal intensity. The exchange of tidal energy and tide -generating force caused by the sun, moon and major planets makes the earths layers rotate in different speeds. The differenti-al rotation between solid and fluid of the earth is the basic reason for El Nino and global climate change.  相似文献   

LUCC and Accompanied Soil Degradation in China from 1960''''s to 1990''''s   总被引：1，自引：0，他引：1  

JIANG Qigang 《东北亚地学研究》2002,(1)

This paper tries to qualitatively analyze land use and cover changes (LUCC) and accompanied soil degradation in China, the data of World Atlas of Agriculture in 1969, Land Cover Data of Asia in 1992 and Global Assessment of Human Induced Soil Degradation in 1992, etc. have been used. From 1960' s to 1990's, the area of forestland had increased, ara-ble land and paddy as well as grassland had significantly decreased in China. The major type of soil degradation is due to wa-ter erosion, which is widely distributed especially in Loess Plateau and in Southeast and Southwest China, this happened in forestland, grassland and arable land and mainly resulted from deforestation. The secondary type is wind erosion, which is mainly distributed in Northwest China, it happened in arable land and grassland and was caused by overgrazing. Chemical deterioration is distributed in North and Northwest China, which happened in paddy, arable land and grassland. Physical de-terioration only concentrated in local area in North  相似文献   

ABSTRACTS OF THE FIRST JOINT SCIENTIFIC MEETING OF GEOLOGICAL SOCIETY OF CHINA AND GEOLOGICAL SOCIETY OF AMERICA (ROOF OF THE WORLD)     

Chendu  Chin  June - 《《地质学报》英文版》2013,87(Z1)

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1982—2000年中国区域地表反照率时空分布特征   总被引：2，自引：1，他引：1       下载免费PDF全文

王鸽- 《高原气象》2010,29(1):146-151

利用1982—2000年NOAA-AVHRR数据资料,研究了中国区域地表反照率的空间分布及其随时间的变化规律。结果表明,中国区域年均地表反照率在空间分布上有很大的差异,胡焕庸线以西地区地表反照率明显大于以东地区;年平均地表反照率呈现缓慢下降趋势,但是不同地区的变化趋势有所不同,年均地表反照率显著降低的区域主要集中在华北平原,显著增加的区域主要集中在长白山和大兴安岭北部;不同季节地表反照率存在很大的差异,冬季最大,春、夏季次之,秋季最小,且冬季平均地表反照率波动幅度比较大;不同地表覆盖的地表反照率的年际变化也存在比较显著的差异。  相似文献