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811.
激光高度计卫星ICESAT在地学研究中的应用 总被引:11,自引:1,他引:10
介绍了世界首颗激光高度计卫星ICESat及其惟一有效的载荷——地学激光测高系统(GLAS)以及它的科学研究目的和工作原理,论述了ICESat在地学研究中的应用。 相似文献
812.
Impacts of an improved low-level cloud scheme on the eastern Pacific ITCZ-cold tongue complex 总被引:1,自引:0,他引:1
A statistically-based low-level cloud parameterization scheme is introduced, modified, and applied in the Flexible coupled General Circulation Model (FGCM-0). It is found that the low-level cloud scheme makes improved simulations of low-level cloud fractions and net surface shortwave radiation fluxes in the subtropical eastern oceans off western coasts in the model. Accompanying the improvement in the net surface shortwave radiation fluxes, the simulated distribution of SSTs is more reasonably asymmetrical about the equator in the tropical eastern Pacific, which suppresses, to some extent, the development of the double ITCZ in the model. Warm SST biases in the ITCZ north of the equator are more realistically reduced, too. But the equatorial cold tongue is strengthened and extends further westward, which reduces the precipitation rate in the western equatorial Pacific but increases it in the ITCZ north of the equator in the far eastern Pacific. It is demonstrated that the low-level cloud-radiation feedback would enhance the cooperative feedback between the equatorial cold tongue and the ITCZ. Based on surface layer heat budget analyses, it is demonstrated that the reduction of SSTs is attributed to both the thermodynamic cooling process modified by the increase of cloud fractions and the oceanic dynamical cooling processes associated with the strengthened surface wind in the eastern equatorial Pacific, but it is mainly attributed to oceanic dynamical cooling processes associated with the strengthening of surface wind in the central and western equatorial Pacific. 相似文献
813.
Eco-geographic regional system is formed by division or combination of natural features based on geographic relativity and
comparison of major ecosystem factors (including biological and non-biological) and geographic zonality. In previous studies,
soil types were often taken as a basis for soil regionalization. However, the quantitative characteristics of soil indicators
are fitter than the qualitative ones of soil types for modern regionalization researches. Based on the second China’s national
soil survey data and the provincial soil resource information, by principal analysis and discriminant analysis, this paper
discusses the appropriate soil indicators as the complement of eco-geographic region indicator systems and the relationships
between these soil indicators and soil types in regionalization. The results show that five indicators are used in eco-geographic
zonality in mid-temperate zone of eastern China which are organic matter content, cation exchange capacity, pH, clay content
and bulk density in topsoils. With a regression-kriging approach, the maps of soil indicators in mid-temperate zone of eastern
China are compiled with a resolution of 1 km in every grid and the indicative meanings of these soil indicators are discussed.
By cluster analysis it is proved that these soil indicators are better than the soil types and soil regionalization in delineating
eco-geographic regions.
Foundation: National Natural Science Foundation of China, No.40771016
Author: Liu Ye (1980–), Ph.D, specialized in integrated physical geography. 相似文献
814.
35 surface soil samples and 28 profile soil samples were collected in Longitudinal Range-Gorge Region, Southwest China. The
distribution of pollen and spores and their relationship with the environment are analyzed. The results show that there are
significant differences in pollen and spores taxa, amounts, dominant taxa and florae between the eastern and western flanks
of the Ailao Mountain. There are more pollen and spores taxa, a greater amount and complexity on the western flank of the
mountain than those on the eastern flank, while the dominant taxa are more centralized and prominent on the eastern flank
of the Ailao Mountain. As for the plant florae distribution, there are significant differences in the number of taxa and composition
between the eastern and the western flanks. The analysis of profile pollen and spores assemblage shows that its trends of
variation are basically in accordance with the surface pollen and spores, which are also indicators of the environmental differences
between the two flanks of the mountain. These significant spatial differences of pollen and spores are very close to the regional
topography and climate difference. The mountain running perpendicular to the moisture-laden air flow serves as a barrier and
the monsoon circulations the east and the west of the mountain result in different energy-moisture characteristics. We conclude
that the main patterns of the pollen and spores can be attributed to the environmental differences. 相似文献
815.
Yaqiong Dai Jinwei Ren Xuhui Shen Jingfa Zhang Shunying Hong Institute of Earthquake Science China Earthquake Administration Beijing China Institute of Crustal Dynamics Beijing China 《地震学报(英文版)》2009,(3):263-269
Digital elevation model (DEM) can be generated by interferometric synthetic aperture radar (InSAR). In this paper, the interferometric processing and analyses are carried out for Damxung-Yangbajain area in Tibet, using a pair of Europe remote-sensing satellite (ERS)-1/2 tandem SAR images acquired on 6 and 7 April 1996. A portion of the In- SAR-derived DEM is selected and compared with the 1:50 000 DEM to determine the precision of the InSAR-derived DEM. The comparison indicates that the root mean squared er... 相似文献
816.
817.
为了更好满足地震计的振动测试需求,对振动台的波形失真度、横向运动比、台面不均匀度及稳定性等主要性能指标进行了测试分析.测试结果表明:该振动台具有较好的低频振动特性.利用低频标准套组对该振动台和中国计量科学研究院标准振动台进行比对分析,测试结果存在较小偏差. 相似文献
818.
为了深入认识四川前陆盆地须家河组沉积物源方向及物源区构造背景,对该盆地次级构造单元内须家河组砂岩碎屑组分、岩屑类型、重矿物组合特征、稀土元素和微量元素进行了分析。结果表明,盆地中的碎屑物源主要来自再旋回造山带,部分可能来自造山之前的混合区,不同的构造单元和层位存在不同物源区的特点:川西坳陷物源主要受龙门山逆冲推覆带控制;川东北坳陷物源主要受米仓山-大巴山逆冲推覆带控制;川东南坳陷物源受雪峰古陆控制,而川中古隆起物源则主要来自南部峨眉瓦山古陆。物源区具有大陆边缘向大陆岛弧转化的构造演化特点,须四期龙门山的逆冲推覆活动明显强于须二期。 相似文献
819.
北京市县域都市农业可持续发展水平动态分异与提升路径 总被引:3,自引:0,他引:3
促进都市农业可持续发展是当前加快新型城镇化进程,统筹城乡一体化发展的重要举措。本文以北京都市农业为研究对象,综合都市农业可持续发展能力时间变化轨迹刻画和空间分异格局归纳两个视角,解析都市农业影响因素的共栖关系和互动效应,结合地区特点提出合理的提升路径,以期为北京都市农业的科学发展提供科学支撑。研究表明:资源环境本底仍是制约北京都市农业发展的关键瓶颈,城镇化和工业化对北京都市农业发展影响具有两面性,宏观经济环境变化中北京都市农业显现出异常的敏感。基于研究结果,提出了促进北京都市农业可持续发展的对策建议:依托资源环境优势,拓展都市农业发展空间;瞄准城市发展需求,提升都市农业产品层次;顺应经济发展趋势,创新都市农业服务体系;创新经营管理体制,培育新型农业经营主体;发掘政策调控潜力,强化都市农业示范作用。 相似文献
820.