Hydrographic conditions during the 2002 SBI process experiments   总被引：3，自引：0，他引：3  

L.A. Codispoti  C. Flagg  V. Kelly  James H. Swift 《Deep Sea Research Part II: Topical Studies in Oceanography》2005,52(24-26):3199

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公用微机硬盘信息保护的一种有效方法   总被引：1，自引：0，他引：1  

张玉彪 《中国海洋大学学报(自然科学版)》1994,(Z2)

介绍一种保护公用微机硬盘信息的有效方法．不仅可以预防各种计算机病毒，更重要的是可以防止人为操作对硬盘信息的破坏。适用于学校等开放性微机实验室的信息安全与保护．  相似文献   

Simulations of Annual Cycle of Phytoplankton Production and the Utilization of Nitrogen in the Yellow Sea     

Tian?TianEmail author  Hao?Wei  Jian?Su  Changsoo?Chung 《Journal of Oceanography》2005,61(2):343-357

A nutrient dynamic model coupled with a 3D physical model has been developed to study the annual cycle of phytoplankton production in the Yellow Sea. The biological model involves interactions between inorganic nitrogen (nitrate and ammonium), phosphate and phytoplankton biomass. The model successfully reproduces the main features of phytoplankton-nutrient variation and dynamics of production. 1. The well-mixed coastal water is characterized by high primary production, as well as high new production. 2. In summer, the convergence of tidal front is an important hydrodynamic process, which contributes to high biomass at frontal areas. 3. The evolution of phytoplankton blooms and thermocline in the central region demonstrate that mixing is a dominant factor to the production in the Yellow Sea. In this simulation, nitrate- and ammonium-based productions are estimated regionally and temporally. The northern Yellow Sea is one of the highly ranked regions in the Yellow Sea for the capability of fixing carbon and nitrogen. The annual averaged f-ratio of 0.37 indicates that regenerated production prevails over the Yellow Sea. The result also shows that phosphate is the major nutrient, limiting phytoplankton growth throughout the year and it can be an indicator to predict the bloom magnitude. Finally, the relative roles of external nutrient sources have been evaluated, and benthic fluxes might play a significant role in compensating 54.6% of new nitrogen for new production consumption.  相似文献   

海洋遥感文献库系统设计     

冷秀华  刘宝银  张杰 《海洋科学进展》2002,20(1):60-65

以中国国家海洋信息中心出版的《海洋文摘》为主要信息源 ,兼顾其它国内外渠道的相关信息 ,设计了电子版的海洋遥感文献库。该库为适合于海洋遥感的专用文献库 ,在查询内容和种类上多于普通的文献库存。文摘与全文混合编排 ,一般文献只录入摘要 ,重点文章全文录入。文献录入前先经过海洋遥感专家的信息评估和质量控制  相似文献   

Ecology of the Symbiotic Coral Cladocora caespitosa (L.) (Faviidae, Scleractinia) in the Bay of Piran (Adriatic Sea): II. Energy Budget     

Christian  Schiller 《Marine Ecology》1993,14(3):221-238

Abstract. The temperate, symbiotic coral Cladocora caespitosa occurs naturally with variable numbers of zooxanthellae. This allows us to study differences in the physiology of symbiotic and "non-symbiotic" polyps and to correlate them with zooxanthellae activities.
Zooxanthellae density in "dark" (normal-colored) polyps was 50 times higher than in "white" (bleached) polyps.
The chlorophyll a content per zooxanthella was 3 times, and Chi c was 13 times higher in white polyps than in dark ones. O₂-flux experiments were conducted with colonies in situ and with single polyps - dark and white - under laboratory conditions. Two approaches were used to evaluate the contribution of zooxanthellae translocation products to animal respiration. Both revealed that the animal tissues derive a higher benefit from the zooxanthellae during periods of low water temperature than during warm periods.  相似文献   

Seasonal Variations in Benthic Community Metabolism and Nitrogen Dynamics in a Shallow, Organic-Poor Danish Lagoon     

Erik Kristensen 《Estuarine, Coastal and Shelf Science》1993,36(6)

The dynamics of benthic primary production and community respiration in a shallow oligotrophic, marine lagoon (Fællestrand, Denmark) was followed for 1·5 years. The shape of the annual primary production cycle was explained primarily by seasonal changes in temperature (r² = 0·67-0·72) and daylength (r² = 0·63), whereas temperature almost explained all variation in benthic community respiration (r² = 0·83-0·87). On a daily basis the benthic system was autotrophic during spring and summer supplied by 'new' and 'regenerated' nitrogen and predominantly heterotrophic during fall and winter caused by light and nutrient limitation. The linear depth-relationship between porewater alkalinity and ammonium indicated that the C:N ratio of mineralized organic matter is low in spring and summer (3-6) and high in fall and winter (9-16). This is inversely related to net primary production and thus the input of labile, nitrogen-rich algal cells. Accordingly, mineralization occurred predominantly in the upper 2-5 cm of the sediment. The pool of reactive material (microalgal cells) was estimated to account for 12% of total organic carbon in the upper 3 cm, and had an average turnover time of less than 1 month in summer. Assimilation of organic carbon by benthic animals was equivalent to about 30% of the annual gross primary production. Grazing reduced chlorophyll a concentration in the sediment during summer and spring to values 30-40% lower than in winter, but maintained a 3-4 times higher specific microalgal productivity. The rapid turnover of organic carbon and nitrogen, and important role of benthic microalgae showed that the benthic community in this oligotrophic lagoon is of a very dynamic nature.  相似文献   

The role of sex change, growth and mortality in Pandalus population dynamics and management     

Fu  Caihong; Quinn  Terrance J.  II; Shirley  Thomas C. 《ICES Journal of Marine Science》2001,58(3):607-621

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台湾海峡海洋捕捞业管理策略和投资方向   总被引：1，自引：0，他引：1  

戴天元 《台湾海峡》1997,16(2):239-244

本文收集了１９８５￣１９９４年福建省在台湾海峡生产的具有代表性的５０对拖网渔船、１２０艘单拖渔船、４８组灯光围网渔船、３８对大围缯渔船、３１艘定置网渔船的技术参数及生产资料，计算并分析了其适正捕捞力量、经济指标，得出了一些有益的结论：（１）根据台湾海峡渔业资源，把握正确的投资方向，已成为进一步发展海洋捕捞业的关键。（２）由于台湾海峡的渔业资源正遭受越来越大的压力，为了保护渔业资源，应当限制捕捞力量  相似文献   

牙鲆种群动态及其资源管理     

朱鑫华 《海洋与湖沼》1992,23(3):270-279

本文根据1980—1986年间鱼类生物学参数测定,结合体长分布资料的模拟分析,研究黄、渤海区牙鲆种群年龄结构、死亡动态以及在不同年龄和死亡率条件下世代资源生物量变化的规律。模型分析结果表明,当F=1.0和t_c=6.0a时,单位补充量最大群体产量为1492g。由此认为,现阶段牙鲆资源利用的最佳策略是通过增殖放流,增加资源补充;同时应适当控制捕捞压力,减少渔具对幼鱼资源的破坏并增设繁殖保护区,以追求最大持续产量。  相似文献   

地磁场强度变化对暴露年代测定的影响及校正     

邵庆丰  陈仕涛 《海洋地质与第四纪地质》2007,27(1):87-93

在103-105a的尺度上,地磁场强度变化是影响陆地宇生核素生成速率的主要因素,其影响程度取决于样品的地理位置和暴露时间。根据已有的磁场古强度数据,模拟200 ka以来海拔2 km、25°N和40°N的地表10Be生成速率的变化,进而分析地表宇生核素生成速率变化对岩石暴露年代测定的影响及其模式年龄的校正。校正磁场强度变化后,海拔2 km、25°N上,50-200 ka的模式年龄可被压缩14%~19%,大于1σ的误差,相同海拔40°N上的模式年龄可减小约8%。对中低纬两组模式年龄的校正充分证明,磁场强度引起的陆地宇生核素生成速率变化是暴露年代测定中主要误差源之一,尤其在低纬高海拔地区这一影响更不容忽视。  相似文献