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61.
62.
Discussion of gas enrichment mechanism and natural gas origin in marine sedimentary basin,China 总被引:4,自引:0,他引:4
《科学通报(英文版)》2007,52(Z1)
There are abundant natural gas resources in Chinese marine sedimentary basin. The exploration hot shots of natural gas are the Palaeozoic marine strata here in recent years, and several large scale gas fields have been discovered. Chinese Palaeozoic high-post matured and coal measure hydrocarbon source rocks are mainly prone to gas generation in the present. This research considered that gas source rocks and TSR are the key cause of gas enrichment of marine strata. High-quality argillaceous and coal measure hydrocarbon rocks are distributed widely in the Palaeozoic marine strata, which have been in highly matured phase in the present. The argillaceous source rock generally contains various sulfates that could accelerate crude oil cracking to gas for TSR occurrence, and coal measure source rock mainly generates gas, so Chinese marine basin gives priority to accumulating gas. Marine strata have not founded oil reservoirs in the Sichuan Basin and Ordos Basin, and they consist mainly of dry gas. Marine natural gases are the mixed gases of oil cracking gas and coal-formed gas in a general way, oil cracking gases contain usually some H2S and CO2. Hydrocarbon carbon isotopes are very complicated, and methane and ethane isotopic values bear apparent reversal caused by thermal evolution and mixing among different genetic types of natural gas. Coal-formed gases are the main component of Chinese marine natural gas. The Upper Permian of the Sichuan Basin and the Carboniferous-Permian of the Ordos Basin coal measure hydrocarbon source rock present large hydrocarbon generation potential, which are the prospecting highlight of marine natural gas hereafter. Oil cracking gas exploration will be paid much attention to in the Tarim Basin because of the lack of coal measure hydrocarbon source rock. 相似文献
63.
海水养殖对海域生态系统的影响及其生物修复 总被引:2,自引:0,他引:2
海水养殖业的迅速发展对海域生态系统产生了一系列的严重影响,本文综述了海水养殖带来的营养盐污染及沉积环境变化、药物使用污染、对天然生物的影响等问题.对于海水养殖造成的问题,有着多种治理方式,基于养殖生态系统的生物修复,是近年来新兴的安全有效的修复方法.本文介绍了微生物修复、大型海藻修复、贝-藻修复、人工湿地修复等生物修复方法及其研究进展.随着研究的不断深入,治理的方式也越来越多,但要想从根本上解决海水养殖带来的污染及影响,基于生态系统的海水养殖管理乃是实现海水养殖业可持续发展的关键. 相似文献
64.
南海北部大陆架海洋生态系统Ecopath模型的应用与分析 总被引:8,自引:1,他引:8
过度捕捞和环境恶化导致渔业资源和海洋生态系统逆向发展。采用EwE5.1软件,对南海北部大陆架建立Ecopath(生态通道模型)模型。通过各级流量、生物量、生产量、捕捞量、系统总流量以及生态位和混和营养效应等方面的分析,得出营养流通主要有2种途径,肉食鱼类间饵料竞争非常激烈,低值鱼类间具相似的捕食压力,顶级捕食者对大部分鱼类负效应不明显。系统受过度捕捞渔业影响很大,并存在营养级I利用效率低和渔业资源小型化、低值化等不稳定的幼态特征。 相似文献
65.
66.
本文根据网络课程设计原则,利用网上教学技术和教学资源的研究与开发,提出轮机英语网络课程的构建原则、方法和构建框架,使轮机英语在教学质量上得到提高,为学生带来很多方便,提供协作化的学习环境,并指出轮机英语网络课程的设计和开发是当前促进专业英语课程建设的有效途径之一。 相似文献
67.
G. Cimino S. De Rosa S. De Stefano G. Sodano 《Cellular and molecular life sciences : CMLS》1985,41(10):1335-1336
Summary Polygodial (1), the defense metabolite stored in the skin of the nudibranchDendrodoris limbata, is toxic for the mollusc itself when injected into the hepatopancreas. Biosynthetic experiments using labeled mevalonic acid were devised to investigate a possible metabolic relationship between1 and the mixture of sesquiterpenoidic esters2, stored in the hepatopancreas. The results suggest that1 and2 are biosynthesized by independent pathways.Thanks are due to G. Villani for supplyingDendrodoris limbata and to A. Trabucco for technical assistance. 相似文献
68.
Summary A new norsesterterpene, hyrtial4, and known sesterterpenes,1–3, have been isolated from an anti-inflammatory active crude extract of the spongeHyrtios erecta.This sponge,Hyrtios (Heteronema) erecta Keller 1889, collected in 1980/81, from Tonga was extremely abundant in the Vava'u Is. Group.We thank Prof. R. Jacobs and his research group at UCSB for this data. 相似文献
69.
资源定位的海洋功能区划和沿海城市概念规划 总被引:1,自引:0,他引:1
王佩儿 《浙江万里学院学报》2008,21(2):91-94
不同的使用者和部门在海洋资源利用上的矛盾冲突往往导致海洋资源的无序开发,甚至破坏海洋生态系统.海洋功能区划是解决上述冲突的一种有效手段.然而目前无论是理论上还是实践上对于海洋功能区划的认识还存在一定的不足.文章以浙江省宁波市象山港的海洋功能区划作为研究案例,根据资源定位原则,将象山港划分为7个海区,并应用环境经济学的分析方法确定了全海域和各海区的主导功能.文章还以厦门市为例,介绍了如何将海洋功能区划结合到沿海城市的概念规划中.资源定位的海洋功能区划对沿海城市的资源持续利用和发展战略的制定有长远的指导意义. 相似文献
70.
ZHANG ShuiChang LIANG DiGang ZHU GuangYou ZHANG XingYang ZHANG BaoMin CHEN JianPing ZHANG Bin 《科学通报(英文版)》2007,52(A01):28-43
The Paleozoic strata in the Tarim Basin, Sichuan Basin and Ordos Basin are the major targets for marine petroleum exploration, with developed high quality hydrocarbon, mainly argillite. The deep burial of these source rocks suggests that they mainly develop gas instead of oil. But different maturities of organic matter may lead to different hydrocarbon facies. Through thermochemical sulfate reduction (TSR), the hydrocarbon in the carbonate rocks may undergo a process of pyrolytic cracking and be catalyzed into gases. The marine reservoirs mainly consist of carbonate and clastic rocks, and the former is controlled by sedimentary facies, dolomitization, solution, TSR and cracking. The multiphase tectonic cycling develops multiple source-reservoir-cap combinations and diversified types of traps and reservoirs, featuring multiphase reservoir formation, mainly late-phase formation or consolidation. Palaeo-uplifts play a controlling role in hydrocarbon accumulation. Differences in major source rocks in the three basins lead to different locations of oil-gas accumulation layers, different types and patterns of reservoirs and different features of reservoir formation. 相似文献