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771.
由于经验和技术缺失,我国冰区滨海核电站的冷源取水安全受到海冰的威胁。数值模拟预警是建立和完善核电冷源取水安全保障系的关键部分。本文以辽东湾东岸的红沿河核电站为例,介绍了 3 种主要的核电冷源安全海冰致险模式,给出了
不同致险模式的数值模拟预警流程,并对数值模拟范围的选取进行重点阐述。结果表明,满足 24 h 预警需求的海冰数值模拟范围面积在数百甚至数千平方公里以上,较大的模拟范围与高网格分辨率对运算能力提出了较高的要求,是目前该数值模拟预警需要解决的突出问题。 相似文献
772.
Seasonal fishing closures are often used in fisheries management to conserve overfished stocks.As one of the unintended consequences,fishermen often contend for maximizing catches immediately after reopening fisheries.The resultant large catch landings in a short time period(i.e.,pulse fishing)may undermine the benefit of closure.We implemented an end-to-end model OSMOSE-JZB(Object-oriented Simulator of Marine ec OSystem Exploitation OSMOSE)modelling ecosystem in the Jiaozhou Bay located in China to evaluate the impact of pulse fishing on the effectiveness of seasonal closure at levels of fish community,population,and individual.Our study demonstrated that the three-month closure was successful in conserving fish stocks.There were small variations on ecological indicators(i.e.,total biomass of the community,mean trophic level of the community,mean trophic level of the catch,and Shannon-Wiener biodiversity index)when pulse fishing occurred.Pulse fishing seemed not to result in a great shift in community structure.Compared to other species,the biomass of two large predatory fishes were more susceptible to pulse fishing.Pulse fishing could change the pressure of predators to fish stocks via food webs,especially for young individuals.Our simulations indicate that we can improve the effectiveness of seasonal closure by managing pulse fishing.Although the results derived in this study may be specific to the target ecosystem,the general approach is applicable to other ecosystems when evaluating fishing impacts. 相似文献
773.
The Tasmanian rock lobster industry has been managed by Individually Transferable Quotas (ITQs) and several input control measures since 1998. In this study, nine years of rock lobster fishing business data were used to categorise the catch and quota ownership traits and examine the response to the introduction of ITQ management. More specifically the study investigates how profit drivers moderated industry structure change. 相似文献
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通过对上海市全市两万多千米的电缆实施数据整合、处理与入库,建立并完善了不同类别电力管线数据整合、技术处理、作业细则、质量控制等一套数据建库的技术文件和实现方案. 相似文献
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The use of trade measures to combat illegal, unreported and unregulated (IUU) fishing in the Northeast Atlantic has evolved from unilateral denial of the landing of fish taken outside international quota arrangements to a multilateral Scheme of Control and Enforcement under the North-East Atlantic Fisheries Commission (NEAFC). International trade rules have not constrained this development, mostly due to successful management of the interplay between international resource management and trade regimes. States protect resource management objectives from such constraint by inserting clauses that establish a normative hierarchy, or they employ various means for adapting IUU measures to the ‘environmental window’ of the global trade regime. The fact that regional states have introduced trade restrictions only when non-restrictive or less restrictive measures have failed enhances such compatibility, as do the gradual shift from unilateral to multilateral measures and the rise in transparency, openness and target-state involvement. None of those features reduces the effectiveness of regional trade measures; they minimize tension with trade commitments and largely strengthen their clout in the struggle to combat IUU fishing in the Northeast Atlantic. 相似文献
779.
智利外海竹筴鱼中心渔场时空变动的初步研究 总被引:9,自引:0,他引:9
根据2005年3~12月14艘中国渔船在智利外海的竹筴鱼生产统计数据和卫星遥感反演的海表温度、叶绿素浓度,分析智利外海竹筴鱼中心渔场的时空变动以及渔场与环境因子的关系.结果表明,随着南半球秋季转入冬季,竹筴鱼中心渔场相应地由南向北、由东向西推移,10月份渔场达到最北端,春末夏初开始南撤;智利外海竹筴鱼渔场的表层水温大致为12~16℃,中心渔场为14~15℃,月间略有差异;渔场的叶绿素质量浓度大致为0.06~0.12 mg/m~3,当渔场的叶绿素质量浓度处于0.08~0.10 mg/m~3时,渔船作业频次和竹筴鱼产量最高. 相似文献
780.
主电站作为海洋石油开采平台最重要的核心组成,为整个平台提供动力来源,是保证平台能够正常运转的心脏器官。从机组类型、特点,以及相应的工作原理等几个方面对海洋石油开采平台上的主电站作了简要的描述;依据相关基础数据,结合锦州25—1南油气田的特点,对油气田进行了电负荷分析,得出油气田设计所需要的典型电负荷量以及相关的数据;通过对机组容量、负荷率、备用率、机组占用平台面积、机组重量等几个参数的比对,从往复式发动机电站机组和燃气透平机电站机组中优选出了主电站机组方案。通过对锦州25—1南油气田主电站方案优选的详细阐述,为海洋石油开采平台主电站的选型设计提供参考和借鉴。 相似文献