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991.
Based on the twice-daily marine atmospheric variables which were derived mostly from the weather maps for 18 years period
from 1978 to 1995, the surface heat flux over the East Asian marginal seas was calculated at 0.5°×0.5° grid points twice a
day. The annual mean distribution of the net heat flux shows that the maximum heat loss occurs in the central part of the
Yellow Sea, along the Kuroshio axis and along the west coast of the northern Japanese islands. The area off Vladivostok turned
out to be a heat-losing region, however, on the average, the amount of heat loss is minimum over the study area and the estuary
of the Yangtze River also appears as a region of the minimum heat loss. The seasonal variations of heat flux show that the
period of heat gain is longest in the Yellow Sea, and the maximum heat gain occurs in June. The maximum heat loss occurs in
January over the study area, except the Yellow Sea where the heat loss is maximum in December. The annual mean value of the
net heat flux in the East/Japan Sea is −108 W/m2 which is about twice the value of Hirose et al. (1996) or about 30% higher than Kato and Asai (1983). For the Yellow Sea, it is about −89 W/m2 and it becomes −75 W/m2 in the East China Sea. This increase in values of the net heat flux comes mostly from the turbulent fluxes which are strongly
dependent on the wind speed, which fluctuates largely during the winter season.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
992.
993.
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995.
sitively.He thoroughly analyzed and criticized the subjectivism in the party by the Marxism standpoint,the viewpoint and the method.He explained and expounded "seek truth from facts" that it is the soul of Marxism tradition thought to the entire party scientifically,and developed the Marxism scientific spirit.So he has contributed 相似文献
996.
Sloshing in a two-dimensional rectangular tank in horizontal motion is analysed based on the velocity potential theory. It is found that even when the first-order excitation is away from all the natural frequencies of the tank, second-order resonance can still occur when the sum-frequency or the difference-frequency is equal to one of the natural frequencies corresponding to the even mode. However, such resonance is not excited when the sum or difference frequency is equal to the natural frequency of an odd mode. 相似文献
997.
An overview of the Oyashio ecosystem 总被引:3,自引:0,他引:3
The Oyashio shelf region and the seasonally ice-covered areas north of Hokkaido are highly productive, supporting a wide range of species including marine mammals, seabirds and commercially important species in the western subarctic Pacific. The fishes include gadids, such as walleye pollock and Pacific cod, and subarctic migratory pelagic fishes such as chum salmon and pink salmon. It is also an important summer feeding ground for subtropical migrants such as the Japanese sardine, Japanese anchovy, Pacific saury, mackerels, Japanese common squid, whales and seabirds. In recent decades, some components of the Oyashio ecosystem (i.e., phytoplankton, mesozooplankton, gadid fish, and subtropical migrants) have shown changes in species abundance or distribution that are correlated with environmental changes such as the 1976/1977 and 1988/1989 regime shifts. The First Oyashio Intrusion moved northward from the mid-1960s until the late 1970s, when it moved southward until the 1980s, after which it returned to the north again after the mid-1990s. The sea-surface temperature in spring decreased after the late 1970s, increased after the late 1980s, and remained high during the 1990s. The extent of ice cover in the Sea of Okhostk also decreased during the latest warming in the 1980–1990s but has increased again since the late 1990s. This and other variabilities affect the Oyashio ecosystem and the surrounding region. 相似文献
998.
The expansion of offshore activities and the increasing need to meet international and national commitments to biodiversity conservation have led to an enhanced interest in marine spatial planning (MSP) as a tool for sea use management. Several European countries, on their own initiative or driven by European legislation and policy, have taken global leadership in implementing MSP. This article will discuss the Belgian experiences with MSP. It will give a short historical overview based on legal developments and review the implementation process of a ‘Master Plan’ as a spatial management policy for the Belgian Part of the North Sea. Additionally, this article will reflect on the research that has been done in Belgium to apply a land-use planning approach to the marine environment. The MSP process in Belgium shows that a spatial approach to sea use management is possible despite the lack of a legal zoning framework. However, it concludes that a legal basis for MSP, in addition to the current permit system, would provide a more strategic and integrated framework for ecosystem-based, sea use management. 相似文献
999.
东海表层水体中的多环芳烃及其沉积通量估算 总被引:2,自引:0,他引:2
以东海陆架水体中溶解态多环芳烃(PAHs)含量为基础,引入颗粒相-水相间的物质吸附系数(Koc)计算悬浮颗粒物中PAHs有机碳归一化含量,结合陆架沉积物有机碳的年埋藏通量,估算东海陆架沉积物中PAHs沉积通量。结果显示:水体中溶解态的15种PAHs总含量为(701±392)ng/L,变化范围为412~1 032ng/L,PAHs组成以3环为主。计算得到的悬浮颗粒物中15种PAHs有机碳归一化含量为20~28μg/g,对应的PAHs沉积通量为150~210t/a。估算结果与实测沉积物中PAHs含量和沉积通量结果基本吻合,表明实验室模拟实验获取的化合物Koc值适用于东海颗粒相-水相间的分配模型,证实悬浮颗粒物有机碳含量在控制PAHs两相分布过程中起着重要作用。同时,该方法为海洋沉积物中PAHs沉积通量的估算提供一种新途径。 相似文献
1000.
东海深井高温高压低孔渗储层钻井技术研究与应用 总被引:1,自引:0,他引:1
随着近年东海勘探工作量的迅速增加,钻井深度越来越深,面临着深层高温高压低孔渗地层钻井的一些重大技术难题.针对遇到的难题,分析研究了钻井技术和工艺,主要包括深部复杂压力体系井身结构优化、构建储层保护和井壁稳定性能良好的低自由水钻井液体系、高压低孔渗储层防气窜固井工艺技术、分井段钻井提速配套技术.研究成果应用表明,该套技术较好地解决了钻井过程中出现的问题,保护了储层,提高了时效,满足了产能测试的要求. 相似文献