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371.
The South China Sea is the largest marginal sea of west Paicfic Ocean.Its valuable to the continental margin.The evolution of Tethyan structure is a very important part of the evolution of the South China Sea.Its formation is due to a sequence opening and closing of Tethys Ocean loke a horn,and made violent influence to the evolution history of the global geologic strcture.When Gondwana continent separated from Euro-Asian continent in the norh,there produced a series of small oceanic basins. The fromation of new oceanic basin was in company with the extinction of the older ones. This recyeling of new oceanic basin was in company with the extinction of the older ones. This reaycling function made the formation of a huge strucfor successive continental margin and oil-gas exploring. Furthermore, it is impirtant for discovering the relationship brtween Tethyan realm and Pacfic realm. In this paper,the authors have done 3 gravtational models basing on deep crustal research,and they want to discuss the reace of Tethyan structure in the northern slope of the South China Sea. 相似文献
372.
Fenneropenaeus chinensis distributed in the Yellow Sea and Bohai Sea of China and the west coast of the Korean Peninsula. Different geographical populations represent potentially different genetic resources. To learn further the characteristics of different geographical population, crosses among two wild and three farmed populations were produced. The two wild populations were from the Yellow Sea and Bohai Sea (WYP), and the west coast of the Korean Peninsula and coast (WKN). The three farmed populations included the offspring of first generation of wild shrimp from coast in Korea (FKN), the Huang Hai (the Yellow Sea in Chinese) No.1 (HH1), and JK98. The phenotypes growth and survival rates of these populations were compared to confirm the feasibility for crossbreeding. The body length (BL), carapace length (CL). carapace width (CW), height of the second and third abdominal segment (HST), width of the second and third abdominal segment (WST), length of the first abdominal segment (LF), length of the last abdominal segment (LL), live body weight (BW), and survival rate were measured, Different combinations were statistically performed with ANOVA and Duncan's Multiple Range Test. The results show that the survival rate of JK98(♀)×WKN(♂) was the highest, followed by WYP(♀)×WKN(♂), FKN(♀)×WYP(♂), FKN(♀)×HHI(♂) and WYP(♀)×FKN(♂); the body weight of FKN(♀)×HHI(♂) was the highest, followed by FKN(♀)×WYP(♂), WYP(♀)×WKN(♂), WYP(♀)×FKN(♂) and JK98(♀)×WKN(♂); the total length had the same ranking as the body weight. All growth traits in hybrids JK98(♀)×WKN(♂) were the lowest among all combinations. F1 hybrids had significant difference (P〈0.05) in BL, CL, HST, LL, and BW; and insignificant difference (P〉0.05) in other growth traits and survival rate. The results of Duncan's Multiple Range Test are that BL and CL of J 相似文献
373.
湖泊水资源持续损失已经成为影响半干旱地区经济社会发展的主要问题之一.然而,由于缺少长期连续的湖泊动态监测数据,该地区湖泊水资源损失过程及其与气候变化和经济社会发展之间的关系没有得到详细的评估.针对此问题,本文以位于半干旱地区的岱海为研究对象,利用改进型归一化差异水体指数从1986—2020年258景Landsat遥感影像中提取湖泊水体边界,结合湖泊水位数据,重建了近60a岱海水资源量动态变化过程.结果表明:1961—2019年期间,岱海急剧萎缩,湖泊水量共减少9.88×108m3.同时水量变化趋势分段函数拟合结果表明,岱海水量变化可分为3个阶段:1961—1978年,水量损失速率为0.726×107m3/a的缓慢损失阶段;1979—2004年,水量损失速率为2.10×107m3/a的快速损失阶段;2005—2019年,水量损失速率为3.39×107m3/a的加速损失阶段.相关分析表明:岱海水量损失与流域经济社会发... 相似文献