Patterns in diversity and community structure of epipelagic copepods from the Brazil–Malvinas Confluence area, south-western Atlantic

Diversity and structure of epipelagic copepod communities were investigated using 70 zooplankton samples collected from the top 50 m of the Brazil–Malvinas Confluence area between 35° and 55°S. Biogeographic patterns were investigated using multivariate analysis. Biodiversity patterns were examined using different univariate indexes. Representatives of 35 species of copepods from 23 genera and 13 families were found. Two zones were delimited based on their copepod composition, one in the subtropical waters of the Brazil current, and the other in the subantarctic waters of the Malvinas current. Both environments displayed contrasting patterns of biodiversity depending upon which element is measured (regional species richness as well as mean point species richness were significantly higher in the subtropical group of stations, whereas taxonomic distinctness was significantly higher in the subantarctic community). Based on these contrasting results, we suggest the use of both kind of indexes when defining priority areas for conservation.     

边际油田-WZ11—1N开发的工程策略

讨论了北部湾边际油田-WZ11-1N油田开发的工程策略，通过技术和经济上的综合分析，WZ11-1N油田采用了“三一”模式依托开发的成果，在应用涠洲地区成熟的、较先进的工程技术和开发经验的基础上，对依托平台／管线的处理工艺和寿命进行了详细的优化和校核，同时采用了电力组网新技术，达到了降低工程投资，提高油田收益的目的。另外在总体布置上为未来油田的依托开发预留了空间。     

交通枢纽布局立体化和流线管道化的设计实践

深圳北站交通枢纽功能齐全、接口复杂。结合北站枢纽的建设实践,通过分析交通枢纽各交通功能的建设规模、主次地位和换乘关系,提出"功能布局立体化和流线组织管道化"的设计理念。通过集约化的方式统筹规划建设,充分利用有限的土地资源,拓展城市发展空间,形成功能齐全、运营高效、换乘便捷的综合交通枢纽。自2011年6月建成投入使用以来,客流快速增长,换乘方便,步行距离短,服务设施齐全,各方评价较高。全面阐述其相关原则、重点、要求和具体措施等设计实践,为其他交通枢纽的规划设计提供参考和借鉴。     

地铁车站装配式铺盖体系设计

论述北京地区首次在地铁9号线丰台北路站应用装配式铺盖体系。从结构计算方法、荷载选取、方案设计、铺盖板的设计及试验和支撑体系计算等方面,系统阐述装配式铺盖体系的设计要点。实践表明,装配式铺盖法能够有效降低地铁施工对周边环境和交通的影响,临时路面效果理想,同时大部分构件能够重复利用,具有良好的经济性与适用性。     

北美铁路降低轮轨接触应力新进展

介绍了北美铁路在降低轮轨接触应力和轮轨作用力方面的研究成果.     

Egg production and associated losses of carbon, nitrogen and fatty acids from maternal biomass in Calanus finmarchicus before the spring bloom

We present concurrent data on ingestion, egg production and the loss of maternal biomass in pre-spring bloom female Calanus finmarchicus incubated under conditions representative of those in situ in the North Atlantic. A balanced metabolic budget was constructed and used to examine the relative importance of ingestion and biomass for fuelling egg production during the incubations. Ingested carbon was not sufficient to meet the observed demands for egg production. More than 80% of the carbon utilised by the females was instead derived from their biomass. Fatty acid analysis demonstrated that the storage reserves, 20:1 (n−9) and 22:1 (n−11), were virtually absent before experimentation began, and therefore could not have been used to supply the carbon required for egg production during the incubations. The C:N mass-specific ratio of the biomass utilised was 4.1, suggesting that the females had instead catabolised protein in order to meet their metabolic demands. These results suggest that C. finmarchicus adopts a sacrificial reproductive strategy when food availability is low.     

长江口北支中束窄工程对周边水动力及水质的影响

基于考虑水体斜压的MIKE3数值模型的HD模块和Ecolab模块,对长江口及附近海域水动力环境进行数值模拟,并将验证好的模型用于分析预测实施北支中束窄工程对周边水动力环境造成的影响。研究结果表明:中束窄工程围填后,北支流速均有一定程度的降低,北支上段汊口处受到南支涨潮的影响,涨急流速有增大趋势;北支束窄工程对盐度的影响趋势为北支区域盐度值有明显的降低,对枯季北支的盐度倒灌南支起到了明显的控制作用;工程实施后,北支河口处磷酸盐、无机氮与叶绿素a含量增加明显;北支中上段磷酸盐与无机氮平均浓度略有降低,而叶绿素a含量整体有上升趋势。工程围填对南支及外海区域的水动力特征及营养盐含量影响较小。     

Estimates of vertical mixing during a Lagrangian experiment off the Galician coast

An adjoint 1-D model was used to determine vertical diffusivity coefficients from temperature profiles collected within a filament escaping from the Galician coast following an upwelling event. The optimisation scheme ended with relatively high diffusivity values within the thermocline (9×10⁻⁵ m² s⁻¹). Such high values are relevant for biogeochemical exchanges between surface and deep waters in stratified areas.The optimised values were several orders of magnitude higher than the bulk of diffusivity measurements recorded with a free-falling device; however, the optimisation solution was consistent with the arithmetic mean of the measurements in the thermocline (7.7×10⁻⁵ m² s⁻¹), giving more weight to the few largest values. Below the thermocline, the data assimilation method failed because of the three-dimensional nature of the advective field of the upwelling system. Ignoring this advective forcing in the model led to estimates that were two orders of magnitude too high.The results suggest that turbulent mixing is a random process where a few intense events determine the average mixing that drives the long-term evolution of the water column structure. This statistical property is very important when one wants to use instantaneous diffusivity measurements for modelling purposes.     

Norwegian North Sea action programme: Analysis of measures to reduce nutrient inputs

According to the terms of the Ministerial Declaration on the Protection of the North Sea, input of the nutrients phosphorus (P) and nitrogen (N) to the coast from the Norwegian‐Swedish border to Lindesnes should be reduced by about 50% between 1985 and 1995. The State Pollution Control Authority (SFT) has analyzed how Norway can achieve this reduction in the most cost‐effective way and at the same time achieve the greatest possible improvement in water quality along the Norwegian coast and in its watercourses.

Two alternative sets of measures were analyzed, both of which would meet the requirements of the Declaration. The lowest‐cost alternative would have average annual costs of about NKr 930 million (U.S.S150 million), and investments of about NKr 4000 million (U.S. $643 million). However, this set of measures would not take account of local water quality, and measures would therefore not always be introduced where the need is most pressing. SFT proposed that an alternative set of measures be implemented, almost all of which would also help to achieve local goals for water quality. This alternative will have annual costs of about NKr 980 million (U.S.$158 million), and investments of about NKr 4100 million (U.S.$659 million).     

Identification of potential sites for deep-ocean waste isolation with a geographic site-selection model

Identification of optimal sites for the isolation of waste on the abyssal seafloor was performed with two approaches: by the traditional method of map overlays of relevant attributes, and by a specially developed, automated Site-Selection Model (SSM). Five initial, Surrogate Sites, identified with the map-overlay approach, were then compared with the more rigorously produced scores from the SSM. The SSM, a process for optimization of site locations, accepts subjective, expert-based judgments and transforms them into a quantitative, reproducible, and documented product. The SSM is adaptable to any siting scenario. Forty-one factors relevant to the isolation scenario, including 21 weightable factors having a total of 123 scorable categories, have been entered into the SSM. Factors are grouped under project definition, unique environments, anthropogenic, geologic, biologic, weather, oceanographic and distance criteria. The factor scores are linked to a georeferenced database array of all factors, corresponding to 1°×1° latitude–longitude squares. The SSM includes a total of 2241 one-degree squares within 1000 n.m. of the U.S. coasts, including the western North Atlantic, the Gulf of Mexico, and the eastern North Pacific. Under a carefully weighted and scored scenario of isolation, the most favorable sites identified with the SSM are on the Hatteras and Nares Abyssal Plains in the Atlantic. High-scoring sites are also located in the Pacific abyssal hills province between the Murray and Molokai Fracture Zones. Acceptable 1° squares in the Gulf of Mexico are few and of lower quality, with the optimum location on the northern Sigsbee Abyssal Plain. Two of the five Surrogate Site locations, on the Hatteras and Sigsbee Abyssal Plains, correspond to the best SSM sites in each ocean area. Two Pacific and a second Atlantic Surrogate Site are located in low-scoring regions or excluded by the SSM. Site-selection results from the SSM, although robust, are an initial attempt to quantify the site-selection process. The SSM database exposes a significant lack of high-quality information for many areally mappable attributes on the abyssal seafloor, particularly bottom-current speed and measures of biologic productivity and flux. Terminologies and classifications of some measures, such as sediment types, suffer from parochialism and vary by ocean. Considerable research is needed even for a broad understanding of the environmental measures required to make sound societal decisions about use of the abyssal seafloor for disposal or other purposes.