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作者通过收集南沙西南海域近几十年来的油气田（井）勘探资料和多年来我局的工作成果，在研究区域地质、沉积特征、油气地质条件与烃源岩演化的基础上，来分析油气资源在整个盆地横向上和纵向上的分布特征，并总结其规律性。 相似文献
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O'Neill BC Gaffin SR Tubiello FN Oppenheimer M 《Tellus. Series B, Chemical and physical meteorology》1994,46(5):378-389
Non-steady state timescales are complicated and their application to specific geophysical systems requires a common theoretical foundation. We first extend reservoir theory by quantifying the difference between turnover time and transit time (or residence time) for time-dependent systems under any mixing conditions. We explicitly demonstrate the errors which result from assuming these timescales are equal, which is only true at steady state. We also derive a new response function which allows the calculation of age distributions and timescales for well-mixed reservoirs away from steady state, and differentiate between timescales based on gross and net fluxes. These theoretical results are particularly important to tracer-calibrated "box models" currently used to study the carbon cycle, which usually approximate reservoirs as well-mixed. We then apply the results to the important case of anthropogenic CO2 in the atmosphere, since timescales describing its behavior are commonly used but ambiguously defined. All relevant timescales, including lifetime, transit time, and adjustment time, are precisely defined and calculated from data and models. Apparent discrepancies between the current, empirically determined turnover time of 30-60 years and longer model-derived estimates of expected lifetime and adjustment time are explained within this theoretical framework. We also discuss the results in light of policy issues related to global warming, in particular since any comparisons of the "lifetimes" of different greenhouse gases (CO2, CH4, N2O, CFC's etc.) must use a consistent definition to be meaningful. 相似文献
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A bulk O2 budget for Lake Hoare, Antarctica, is presented. Five years of seasonal data show the lake to be persistently supersaturated with O2. Oxygen is carried into the lake in glacial meltstreams and is left behind when this water is removed as ice by ablation and sublimation. A diffusive loss of O2 from the lake through the summer moat is suggested. Measured values of the total O2 in the water column indicate that the time scale of O2 turnover is much longer than a year. Based on these results we suggest that the amount of O2 in the water does not change significantly throughout the year and that the lake is also supersaturated with N2. 相似文献
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南海盆地演化及碳酸盐岩油气勘探 总被引：7，自引：0，他引：7
南海盆地碳酸盐岩油气勘探最早可追溯到19世纪后期,20世纪70年代开始有较多发现。南海的形成演化经历了安第斯型边缘-弧后裂谷-大西洋型海底扩张等一系列转变,形成了众多规模不等、类型各异的新生代含油气盆地。这些盆地可划分为拉张型、聚敛型、走滑型三大类,且可细分为陆缘张裂型、裂离陆块型、弧前型、周缘前陆型、走滑-拉分型以及残留洋壳型等6种类型,不同的构造演化背景和盆地类型,碳酸盐岩的建隆及其生物礁具有不同的特征,其地震相特征也有一定差异。碳酸盐岩主要发育在中中新统一上中新统中及上始新统上部,储层分布范围广,发育有台地边缘礁、塔礁、块礁、点礁、环礁等多种类型,以铸模灰岩、颗粒状白云岩的油气储集性能较好。碳酸盐岩的形成和分布受大地构造演化的影响和控制。以越东-廷贾断裂为界,其北部海域发育晚始新世-早中新世(早期)和中-晚中新世(晚期)两期碳酸盐岩和生物礁;而其南部海域仅发育晚期碳酸盐岩。在南海,至今尚未发现有单纯的典型碳酸盐岩构成油气源岩的,绝大多数是与所伴生的生物礁一起组成储集层,所发现的碳酸盐岩及其生物礁(滩)型油气田,普遍具有较好的物性。在南海北部盆地和东南巴拉望盆地中是油气兼有,而在南海南部以产天然气为主。 相似文献
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McKay CP Grunthaner FJ Lane AL Herring M Bartman RK Ksendzov A Manning CM Lamb JL Williams RM Ricco AJ Butler MA Murray BC Quinn RC Zent AP Klein HP Levin GV 《Planetary and Space Science》1998,46(6-7):769-777
The MOx instrument was developed to characterize the reactive nature of the martian soil. The objectives of MOx were: (1) to measure the rate of degradation of organics in the martian environment; (2) to determine if the reactions seen by the Viking biology experiments were caused by a soil oxidant and measure the reactivity of the soil and atmosphere: (3) to monitor the degradation, when exposed to the martian environment, of materials of potential use in future missions; and, finally, (4) to develop technologies and approaches that can be part of future soil analysis instrumentation. The basic approach taken in the MOx instrument was to place a variety of materials composed as thin films in contact with the soil and monitor the physical and chemical changes that result. The optical reflectance of the thin films was the primary sensing-mode. Thin films of organic materials, metals, and semiconductors were prepared. Laboratory simulations demonstrated the response of thin films to active oxidants. 相似文献
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Almroth BC Sturve J Stephensen E Holth TF Förlin L 《Marine environmental research》2008,66(2):271-277
The use of fish in environmental monitoring has become increasingly important in recent years as anthropogenic substances, many of which function as prooxidants, are accumulating in aquatic environments. We have measured a battery of antioxidant defenses as a measure of oxidative status, as well as protein carbonylation as a measure of oxidative damage, in corkwing wrasse (Symphodus melops) captured near a disused copper mine, where water and sediment are contaminated with heavy metals, and an aluminum smelter, a site contaminated with PAHs. Results were compared to two different reference sites. Fish at the heavy metal site had lower glucose-6-phosphate dehydrogenase activity and elevated protein carbonyls (1.8 times) compared to fish from the reference site. At the PAH site, EROD was increased 2-fold, while total glutathione and methemoglobin reductase concentration, were decreased. No differences were seen in protein carbonyl levels at the PAH site. Measures of both antioxidant defenses and oxidative damage should be used when assessing effects of xenobiotics on oxidative stress in fish species. 相似文献
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沉积物是记录古环境信息源的载体,用海洋的沉积层再造古气候,具有记录连续、定年准确、可全球对比等优点。作者通过对南海众多站位柱状样资料的分析,主要从南海表层沉积物的类型、分布、物质来源和沉积搬运作用以及古气候演替、季风变迁等多方面阐述了晚第四纪以来的南海古环境变迁的特征,并对其与南海周缘地区经济发展的关系作了探讨。 相似文献
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O'Leary BC Smart JC Neale FC Hawkins JP Newman S Milman AC Roberts CM 《Marine pollution bulletin》2011,62(12):2642-2648
We analysed the extent to which European politicians have adhered to scientific recommendations on annual total allowable catches (TACs) from 1987 to 2011, covering most of the period of the Common Fisheries Policy (CFP). For the 11 stocks examined, TACs were set higher than scientific recommendations in 68% of decisions. Politically-adjusted TACs averaged 33% above scientifically recommended levels. There was no evidence that the 2002 reform of the CFP improved decision-making, as was claimed at the time. We modelled the effects of such politically-driven decision-making on stock sustainability. Our results suggest that political adjustment of scientific recommendations dramatically increases the probability of a stock collapsing within 40 years.In 2012 European fisheries policy will undergo a once-a-decade reform. Ten years ago radical reforms were promised but the changes failed to improve sustainability. It is likely that the 2012 reform will be similarly ineffective unless decision-making is changed so that catch allocations are based on science rather than politics. 相似文献