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31.
The properties of salinity in the South China Sea (SCS), a significant marginal sea connecting the Pacific andIndian Oceans, are greatly influenced by the transport of fresh water flux between the two oceans. However, the long-termchanges in the intermediate water in the SCS have not been thoroughly studied due to limited data, particularly in relationto its thermodynamic variations. This study utilized reanalysis data products to identify a 60-year trend of freshening in theintermediate waters of the northern South China Sea (NSCS), accompanied by an expansion of low-salinity water. Thestudy also constructed salinity budget terms, including advection and entrainment processes, and conducted an analysis ofthe salinity budget to understand the impacts of external and internal dynamic processes on the freshening trend of theintermediate water in the NSCS. The analysis revealed that the freshening in the northwest Pacific Ocean and theintensification of intrusion through the Luzon Strait at intermediate levels are the primary drivers of the salinity changes inthe NSCS. Additionally, a weakened trend in the intensity of vertical entrainment also contributes to the freshening in theNSCS. This study offers new insights into the understanding of regional deep sea changes in response to variations in boththermodynamics and oceanic dynamic processes. 相似文献
32.
山西能源重化工基地建设关系到全国四个现代化的实现,被列为国家重点建设工程,制定了《山西能源重化工基地综合规划》。本文分析了80年代山西省经济建设的成就与问题。提出了“整体创新,综合开发”,把山西能源重化工基地建设成内陆经济开放区的战略大思路,为此,90年代应完成11项大型经济战略工程,同时展望了经济发展改革前景。 相似文献
33.
视电阻率定义在电法勘探中得到广泛的应用。目前在频率域电磁法中常常采用远区视电阻率定义。由于在频率域中收发距并非足够大,以致在低频段远区定义视电阻率往往不能反映地下电阻率值。我们定义全区电阻率及引入校正系数K,经二层三层模型及野外实测资料的计算,证明了方法的有效性。 相似文献
34.
35.
基于GIS的区域经济统计分析系统的设计与实现 总被引:1,自引:0,他引:1
随着经济的发展,区域间经济相互作用和影响的关系越来越密切,忽略空间相互作用的传统区域经济分析手段和方法开始显现出一些明显的不足。而GIS在处理和分析区域地理数据上具有强大的空间分析能力,为此我们引入GIS工具对区域经济进行分析,相较于传统的分析手法有了很大改善。本文以江西省区域经济数据为例,设计了一个基于GIS的区域经济统计分析系统,并利用Arcob-jects二次开发控件结合VB可视化编程语言,实现了大部分区域经济统计分析功能,最后并将结果进行网络发布。研究结果表明将GIS引入到区域经济统计分析中,更能正确、有效的揭示区域经济发展在空间上的联系,为区域经济研究决策提供服务。 相似文献
36.
37.
Two elongatoolithid dinosaur eggs from the Upper Cretaceous of Ganzhou, Jiangxi Province and the embryonic skeletons they bear are described. They represent the first oviraptorosaurian eggs with embryonic skeletons in China and provide the first example that an oospecies can be correlated to certain dinosaur taxon/taxa. The two eggs are the same as the pair of the eggs inside a female oviraptorosaurian pelvis from the same horizon of the same area in both macro- and micro-structures of the egg shells, and can he referred to the oospecies, Macroolithus yaotunensis Zhao, 1975. The morphology of the preserved part of the embryonic skeletons indicates that they may have been laid by an oviraptorid, Heyuannia huangi from Guangdong Province or a closely related oviraptorosaurian, which may have been lived in the Ganzhou area too in the Late Cretaceous. The embryonic skeletons of the two eggs are not in the same developing stage. In one of the eggs, the postzygapophysis of the preserved vertebrae are well ossified, indicating that it was just hatched. 相似文献
38.
39.
At present, researches on climate change of the Heihe River basin mainly focus on the relationship between basin climate change
and regional water resources, regional desertification and dynamic climatic seasons of sandstorm, but less on climate change
of oasis region, where there are more intense and frequent human activities. Based on data of precipitation, temperature,
strong wind and dust events frequencies obtained from the six meteorological stations of Zhangye region in Heihe River basin,
the features of climate change during 1968–2005 were carefully studied. Results show that the regional temperature rise rate
exceeded the average level of China. The annual precipitation changed a little, but the precipitation had a slowly increasing
trend in spring and winter. Frequencies of strong wind and sandstorm days show obviously descending trends, which had a close
correlation with the regional temperature rise and the precipitation increase in spring and winter. Meanwhile, further human
economic activities and exploitations to the oasis in the inland valley of arid regions also affected the climate change of
this region, which has a sensitive and fragile eco-environment.
__________
Translated from Journal of Desert Research, 2007, 27(6): 1048–1054 [译自: 中国沙漠] 相似文献
40.
随着地形高差增大、地貌单元多变、近地表模型复杂,目前被广泛应用的初至折射静校正的精度已无法满足精细勘探的要求。初至层析静校正技术,由给定的初始模型进行正演,用射线追踪方法得到初始模型的初至波,利用该初至波和实际拾取的初至波进行比较,计算地表模型的修正量,反复迭代求得准确的地表模型。山西省国阳新能股份有限公司二矿390水平九采扩区地表标高940~1100m,地貌单元复杂,在对该区资料处理时,利用初至层析折射静校正,经9次迭代计算后,真实地刻划出近地表模型。在二种静校正技术对比中,初至折射静校正不但近地表模型精度低于层析折射静校正,而且其叠加剖面精细程度也远低于层析静校正,如在初至折射静校正叠加剖面同相轴上呈现的凹凸形态,在层析静校正叠加剖面并无显示,且后者剖面的信噪比也比前者明显提高。 相似文献