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981.
本溪系不是岩石地层单位,也不是年代地层单位或生物地层单位,而是历史形成的一种习惯用法。根据地层单位清理的原则,本溪系一名应废弃,置原太原群下部,一并称太原群。辽东地区太原群下部建山城子组、二里河组两个岩石地层单位;辽东半岛南部建山城子组、三棱山组两个岩石地层单位替代原本溪系。华北地台太原群下部(本溪系)海侵方向,根据地层厚度,生物繁衍、迁移路线,地层的空间展布及海相层分析,海水应由北东太子河流域向南西侵进。  相似文献   
982.
This study indicates that environmental policy interventions significantly influence the innovation processes for reducing the emissions of marine engine technology. Several different types of interventions have been important and the effect is not directly proportional to the strength or spatial coverage of the intervention. Despite its relative weakness, the MARPOL rule on NOx emissions has contributed to technology development. We also show that the rise of environmental issues in other fields has had a marked effect on the development of the marine sector and that relatively local interventions can influence innovation even in an international sector like marine transport.  相似文献   
983.
An open-path cavity ring-down spectroscopy (CRDS) instrument for measurement of atmospheric iodine monoxide (IO) radicals has been tested in the laboratory and subsequently deployed in Roscoff on the north-west coast of France as part of the Reactive Halogens in the Marine Boundary Layer (RHaMBLe) project in September 2006. In situ measurements are reported of local IO mixing ratios in the marine boundary layer. To obtain these mixing ratios, accurate absorption cross sections of IO are required at the selected wavelengths used for spectroscopic measurements. Absorption cross sections at the bandheads of the IO A2Π3/2–X2Π3/2 (3,0) and (2,0) vibronic bands were thus verified by a combination of spectral simulation methods, inter-comparison of prior determinations of cross-sections at high and low spectral resolution, and by measurement of rates of loss of IO by its self-reaction. The performance of the open-path CRDS instrument was tested by measuring concentrations of NO2 in ambient air, both within and outside the laboratory, with results that were in excellent agreement with a previously validated continuous wave CRDS apparatus for NO2 detection. During the RHaMBLe campaign, the open-path CRDS instrument was located within a few metres of the shoreline and operated at wavelengths close to 435 nm to detect the absorption of light by trace levels of IO. The IO mixing ratios were obtained on two days, peaked close to low tide, and were approximately 5–10 times higher than values calculated from column densities previously reported by long-path, differential optical absorption spectroscopy (DOAS) in coastal regions. The typical detection limit of the instrument was estimated to be 10 pptv of IO, with some fluctuation around this value depending on the conditions of wind and atmospheric aerosol particles, and the total accumulation time was 30 s for each data point. The observations of relatively high concentration of IO, compared to the values previously reported by DOAS, are consistent with the concurrent observations using a LIF (Laser induced Fluorescence) instrument (Whalley et al. in press). The first such measurements of localized IO by CRDS and LIF should contribute to an improved understanding of the chemistry of halogen compounds and the formation of iodine oxide aerosol particles in the marine boundary layer.  相似文献   
984.
大气污染物向海洋的输入及其生态环境效应   总被引:7,自引:3,他引:7  
纵观20年来,特别是近几年来逐渐成为生物地球化学循环研究热点之一的大气对海洋物质输入的研究,从大气物质入海通量,大气物质入海对海洋生态系统和环境的影响,大气物质入海的科学研究计划和项目等方面分析了这一领域的研究现状和未来趋势。给出了不同海区各种主要大气入海物质的通量或在同类物质入海总量中的比例,讨论了氮、磷、铁等营养物质和持续性有毒污染物,如PAH、PCBs、杀虫剂和重金属对海洋生态系统和环境的不同影响。  相似文献   
985.
浪作用下海洋底床动态响应的研究   总被引:4,自引:0,他引:4  
有关波浪作用下的底床动态响应越来越引起人们的重视。本文从海洋土的特点出发,针对各向同性底床和各向异性底床,详细论述了在线性波加载下,波浪衰减和底床动态响应这两方面的研究现状,在分析和比较已有研究成果的基础上,对今后的研究方向提出了自己的看法。  相似文献   
986.
Lv Y  Zhang W  Gao Y  Ning S  Yang B 《Marine pollution bulletin》2011,62(12):2700-2706
This study investigated the responses of marine nematodes to crude oil contamination in polluted and relatively uncontaminated sites in Dalian Xingang, China, 40 days after an oil spill. Samples were taken at different tide levels on the beach and at different positions along the beach. We present the results of a comparison of nematode assemblages from undisturbed sediment from the Xiajiahezi Bathing Beach with those from sediment from the Xinghai Bathing Beach contaminated with crude oil. A total of 1666 nematodes from 26 genera were found in this study. Results showed significant differences in nematode assemblages between samples from undisturbed controls and those from the polluted area. Nematode abundance, number of species, diversity and species richness decreased significantly with increasing levels of crude oil contamination. Fifteen genera were eliminated and seemed to be composed of species intolerant to crude oil contamination; only the abundance of Marylynnia sp. increased slightly.  相似文献   
987.
一次江淮气旋的模拟和海洋敏感试验   总被引:3,自引:2,他引:1  
运用中尺度WRFV3.0模式,对2009年4月19日00时-22日00时期间的一次江淮气旋进行了数值模拟(控制试验CTR)研究,得出在CTR中江淮气旋的路径和发展趋势总体上比较理想,为此进一步设计海洋属性敏感试验,探讨海洋属性对江淮气旋的路径和强度的影响.结果表明:当海洋属性修改成陆地属性后,江淮气旋路径向东南偏移,入海后,偏离程度增大;气旋强度在大别山附近稍有增强,入海后强度减弱.气旋中心南侧的偏南气流、气旋前部的水汽辐合区和强对流有效位能,以及气旋中心附近的强潜热能,均有利于江淮气旋发展.  相似文献   
988.
Increases in the maritime transportation of Hazardous and Noxious Substances (HNS), alongside the need for an effective response to HNS spills have led environmental managers and the scientific community to focus attention on HNS spill preparedness and responsiveness. In the context of the ARCOPOL project, a weight-of-evidence approach was developed aimed at prioritizing HNS that pose major environmental risks to European waters. This approach takes into consideration the occurrence probability of HNS spills in European Atlantic waters and the severity of exposure associated with their physico-chemical properties and toxicity to marine organisms. Additionally, a screening analysis of the toxicological information available for the prioritization of HNS was performed. Here we discuss the need for a prioritization methodology to select HNS that are likely to cause severe marine environmental effects as an essential step towards the establishment of a more effective preparedness and response to HNS incidents.  相似文献   
989.
Plastic debris ingestion by marine catfish: an unexpected fisheries impact   总被引:1,自引:0,他引:1  
Plastic marine debris is a pervasive type of pollution. River basins and estuaries are a source of plastics pollution for coastal waters and oceans. Estuarine fauna is therefore exposed to chronic plastic pollution. Three important catfish species [Cathorops spixii (N = 60), Cathorops agassizii (N = 60) and Sciades herzbergii (N = 62)] from South Western Atlantic estuaries were investigated in a tropical estuary of the Brazilian Northeast in relation to their accidental ingestion of plastic marine debris. Individuals from all three species had ingested plastics. In C. spixii and C. agassizii, 18% and 33% of individuals had plastic debris in their stomachs, respectively. S. herzbergii showed 18% of individuals were contaminated. All ontogenetic phases (juveniles, sub-adults and adults) were contaminated. Nylon fragments from cables used in fishery activities (subsistence, artisanal and commercial) played a major role in this contamination. These catfish spend their entire life cycles within the estuary and are an important feeding resource for larger, economically important, species. It is not yet possible to quantify the scale and depth of the consequences of this type of pollution. However, plastics are well known threat to living resources in this and other estuaries. Conservation actions will need to from now onto take plastics pollution into consideration.  相似文献   
990.
Plastic debris (PD) ingestion was examined in 106 Franciscana dolphins (Pontoporia blainvillei) incidentally captured in artisanal fisheries of the northern coast of Argentina. Twenty-eight percent of the dolphins presented PD in their stomach, but no ulcerations or obstructions were recorded in the digestive tracts. PD ingestion was more frequent in estuarine (34.6%) than in marine (19.2%) environments, but the type of debris was similar. Packaging debris (cellophane, bags, and bands) was found in 64.3% of the dolphins, with a lesser proportion (35.7%) ingesting fishery gear fragments (monofilament lines, ropes, and nets) or of unknown sources (25.0%). PD ingestion correlated with ontogenetic changes in feeding regimes, reaching maximum values in recently weaned dolphins. Because a simultaneous increase in gillnet entanglement and the bioaccumulation of heavy metals take place at this stage, the first months after trophic independence should be considered as a key phase for the conservation of Franciscana dolphin stocks in northern Argentina.  相似文献   
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