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81.
区域海洋地质数据库建设纲要 总被引:5,自引:0,他引:5
区域海洋地质数据库是中国地质调查局基础数据库的一个重要组成部分,是实现地质调查基础性与公益性战略部署的依托。根据区域海洋地质数据库建设的目标与任务,在数据结构和实施步骤等方面进行了初步研究。区域海洋地质数据库及其管理信息系统适合采取基于Web系统的三层体系结构,在数据构成上亦分为区域海洋地质调查原始资料与成果资料,其中元数据库的建设对数据库的应用非常重要,用户可以通过元数据了解数据的存在性、适宜性、有效性等,确定数据的使用方法,因此,元数据库的建设应采用国际已经普遍认可的ISO/TC211发布的ISO19115空间元数据标准。 相似文献
82.
Chunfang Cai Zengye Xie Richard H. Worden Guoyi Hu Lansheng Wang Hong He 《Marine and Petroleum Geology》2004,21(10):1265-1279
New sour pools have recently found in the Lower Triassic Feixianguan Fm carbonate reservoirs in the East Sichuan Basin in China with H2S up to 17.4% by volume. A recent blowout from a well drilled into this formation killed hundreds of people as a result of the percentage concentrations of H2S. In order to assess the origin of fatal H2S as well as the cause of petroleum alteration, H2S concentrations and the isotopes, δ34S and δ13C have been collected and measured in gas samples from reservoirs. Anhydrite, pyrite and elemental sulphur δ34S values have been measured for comparison. The high concentrations of H2S gas are found to occur at depths >3000 m (temperature now at 100 °C) in evaporated platform facies oolitic dolomite or limestone that contains anhydrite nodule occurrence within the reservoirs. Where H2S concentrations are greater than 10% its δ34S values lie between +12.0 and +13.2‰ CDT. This is within the range of anhydrite δ34S values found within the Feixianguan Fm (+11.0 to +21.7‰; average 15.5±3.5‰ CDT). Thus H2S must have been generated by thermochemical sulphate reduction (TSR) locally within the reservoirs. Burial history analysis and fluid inclusion data reveal that the temperature at which TSR occurred was greater than about 130–140 °C, suggesting that the present depth-temperature minimum is an artifact of post-TSR uplift. Both methane and ethane were actively involved in TSR since the petroleum became almost totally dry (no alkanes except methane) and methane δ13C values become significantly heavier as TSR proceeded. Methane δ13C difference thus reflects the extent of TSR. While it is tempting to use a present-day depth control (>3000 m) to predict the distribution of H2S in the Feixianguan Fm, this is an invalid approach since TSR occurred when the formation was buried some 1000–2000 m deeper than it is at present. The likelihood of differential uplift across the basin means that it is important to develop a basinal understanding of the thermal history of the Feixianguan Fm so that it is possible to determine which parts of the basin have been hotter than 130–140 °C. 相似文献
83.
本文研究了虾蟹海产品香味的前体物质在加热前后的变化。实验结果表明:对虾和蟹肌肉中的糖原和不饱和脂肪酸在加热前后含量下降,糖原是Maillard反应的基础物质.不饱和脂肪酸是虾蟹肌肉香味中羰基化合物的前体物质。虾蟹肌肉中主要积累的核苷酸成分AMP在加热后减少,而肌肉提取物中的游离氨基酸和结合氨基酸,特别是疏水氨基酸含量均增加。 相似文献
84.
85.
对类比路段进行连续模拟试验,进行现场调查,给出汽车尾气主要污染物的排污强度,预测了汽车尾气中CO、C_nH_m和NO_x的扩散范围。 相似文献
86.
我国海域分等定级指标体系研究 总被引:3,自引:0,他引:3
长期以来,海域的无偿使用导致海洋开发活动秩序混乱、海洋环境污染加剧、海洋生物资源枯竭、海洋生态环境遭到破坏,严重阻碍和制约沿海地区的可持续发展.本文试图根据经济学的“地租级差”理论和运筹学中的“层次分析法”并结合我国沿海11个省、市和自治区的社会、经济、基础设施、自然资源等因素进行理论探讨,给出了我国管辖海域的等级.为今后我国制定海域有偿使用金的征收标准奠定基础. 相似文献
87.
Xu Shikai Wang Hongchuan Hong Guangwen
Engineer Nanjing Hydraulic Research Institute Nanjing .
Professor Research Institute of Coastal Ocean Engineering Hohai University Nanjing 《中国海洋工程》1996,(4)
To solve problems concerning wave elements and wave propagation, an effective way is the wave energy balance equation, which is widely applied in oceanography and ocean dynamics for its simple computation. The present papaer advances wave energy balance equations considering lateral energy transmission and energy loss as the governing equation for the study of wave refraction-diffraction. For the mathematical model, numerical simulation is made by means of difference method, and the result is verified with two examples. 相似文献
88.
研究流形上的聚类分析,针对基于密度的空间聚类引入了流形概念,提出1种基于流形的密度聚类算法,该方法将流形的概念与聚类相结合,可以适用于样本为复杂分布的聚类。文中通过实例证明此算法的有效性。 相似文献
89.
Evaluation of bending moments and shear forces at unit connections of very large floating structures using hydroelastic and rigid body analyses 总被引:1,自引:0,他引:1
Byoung Wan Kim Sa Young Hong Jo Hyun Kyoung Seok Kyu Cho 《Ocean Engineering》2007,34(11-12):1668-1679
This paper investigates the characteristics of bending moments, shear forces and stresses at unit connections of very large floating structures (VLFS) under wave loads. The responses of VLFS are calculated by solving multi-body motion equation considering hydroelasticity and connection stiffness. Hydroelastic responses are calculated by the direct method. Higher-order boundary element method (HOBEM) is used for fluid analysis and finite element method (FEM) is introduced for structural analysis. The equation of motion is modified to describe the unit connections by employing spring elements. Bending moments and shear forces at the connections are obtained from the dynamic equilibrium condition for pressures and inertia forces. Two types of VLFS units such as tandem arranged units and side-by-side arranged units are considered in the numerical examples. The influences of connection stiffness, wave frequency and heading angle on responses of VLFS are investigated through the numerical examples. Rigid body analysis along with hydroelastic analysis is also carried out in the numerical analysis and comparison of those two approaches is discussed. 相似文献
90.
In this paper, the method of operator splitte is applied to simulate the tidal flow in the Hang-zhou Bay. Different schemes of splitting have been devised and compared.Results of the study indicate that good simulation can be achieved. Besides being simpler in form, this method is flexible and allows much freedom in selecting the mode of splitting and the scheme of computation. 相似文献