共查询到20条相似文献,搜索用时 31 毫秒
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Geology of the athabasca oil sands 总被引:1,自引:0,他引:1
Mossop GD 《Science (New York, N.Y.)》1980,207(4427):145-152
In-place bitumen resources in the Alberta oil sands are estimated at 1350 billion barrels. Open-pit mining and hot water extraction methods, which involve the handling of huge tonnages of earth materials, are being employed in the two commercial plants now operating. In situ recovery methods will be required to tap the 90 percent of reserves that are too deeply buried to be surface mined. Development of in situ technologies will be painstaking and expensive, and success will hinge on their compatibility with extremely complex geological conditions in the subsurface. 相似文献
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Enzymatic catalysts in organic synthesis 总被引:4,自引:0,他引:4
C H Wong 《Science (New York, N.Y.)》1989,244(4909):1145-1152
The synthetic value of enzymes is being increasingly recognized. With an understanding of enzyme-catalyzed reactions and the techniques now available for the low-cost production and rational alteration of enzymes and for the design of new enzymatic activities, biocatalytic synthesis should become one of the most valuable synthetic methods. The fundamental as well as the practical issues of this rapidly growing area are described and its impact on the technology pertaining to synthesis is considered. 相似文献
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钻井布局可以归结为在一定约束条件下利用旧井的地质资料来减少新井的钻探数量,以节省钻探费用的问题,通过网格的移动使可利用的旧井数尽可能多。建立了钻井布局问题的数学模型,设计了基于偏序关系求解钻井布局问题的演化算法,得到了理想的计算结果。结果表明,该算法具有精度高、速度快等特点。 相似文献
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钻井布局可以归结为在一定约束条件下利用旧井的地质资料来减少新井的钻探数量,以节省钻探费用的问题,通过网格的移动使可利用的旧井数尽可能多。建立了钻井布局问题的数学模型,设计了基于偏序关系求解钻井布局问题的演化算法,得到了理想的计算结果。结果表明,该算法具有精度高、速度快等特点。 相似文献
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原油分子筛非临氢浅度裂化改质中试研究 总被引:1,自引:1,他引:0
介绍了原油分子筛非临氢浅度裂化改质降凝减粘新工艺由小试到中试的研究实践。研究结果表明,在小试基础上放大1000倍的中试试验结果和小试试验结果基本一致,验证了该工艺放大试验在技术上是可行的,可以进一步扩大成工业试验和生产。改质原油用于现有管道输油生产可降低输油温度,减少燃耗,尤其可以解决低输量管道的输送问题。原油分子筛改质工艺流程简单,操作简便,投资低,降凝减粘幅度大,改质油性质稳定,内含潜在的经济 相似文献
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[目的]以王不留行中总黄酮得率为指标,确定王不留行的最佳炮制工艺。[方法]通过紫外分光光度法测定王不留行不同炮制品中总黄酮含量。[结果]王不留行不同炮制品中总黄酮含量由大到小为:油砂炒法>清炒法>中火酒炒法>润炒法>砂炒法。[结论]不同炮制方法对王不留行总黄酮成分的含量有着明显的影响,且油砂炒法为王不留行最佳炮制工艺。 相似文献
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油菜高含油量育种研究进展 总被引:2,自引:0,他引:2
近年来,我国油菜生产得到了长足的发展,但由于生产上推广的油菜品种含油量普遍偏低,导致产油量不高。育种家们从20世纪60年代开始关注这个问题,也取得了一些进展。概述了油菜高含油量育种的理论与方法,以及生物技术和分子育种方法在高含油量育种上的应用进展。单株选择、诱变育种、黄籽育种和品种间杂交是高含油量育种的常用方法,育种家已把多种育种方法结合起来用于育种实践中,并结合生物技术和分子育种技术,选育出了很多高含油量的品种。 相似文献
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油脂是人类日常生活必不可少的物质,但受到提取工艺和技术条件的限制,存在出油率不高、溶剂残留等诸多问题。如何有效利用资源实现最佳量效关系一直是现代轻工业亟待解决的问题。因此,研究并改进油脂提取相关工艺技术及方法具有重要的应用价值。通过对油脂传统和现代提取技术方法及其原理的简单介绍、对各种方法主要优缺点的比较,得出对油脂提取方法的总体的和前瞻性的看法,旨在为今后油脂工业的发展提供参考。就油脂提取技术来说.采用绿色工艺进行企业生产,是现代工业发展的趋势。酶提取法、水剂法、超临界CO2萃取法在生物油脂萃取中得到广泛的应用,尤其是超临界CO2萃取法因其具有环保的萃取过程、萃取物纯净无污染、在油脂和中药材的活性成分提取中均有独特优势,随着应用的普及和改善,该技术可能成为油脂萃取的主要技术方法之一。 相似文献
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2008~2013连续6年对六安市油菜主产县(区)采用实地访问的方式随机抽样90户,主要对油菜生产面积、生产管理、生产投入、生产效益、技术需求意愿及农户种油心理倾向等方面进行调查。通过调查,对当前油菜生产现状、存在问题及市场形势作了重点分析。针对存在的问题从政策支持、发展油菜"一菜多用"提高种植效益、推广轻简化生产新技术、加强健康食油宣传并提高食用菜籽油自给率等方面提出对策建议。 相似文献
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Fisher WL 《Science (New York, N.Y.)》1987,236(4809):1631-1636
Aggressive drilling for oil and gas in the lower 48 states of the United States over the past decade yielded reserve additions sufficient to arrest decline and to stabilize levels of production. Such positive response from a maturely explored and developed oil resource base was unpredicted and largely unanticipated. Two elements of the recent experience-maintenance of stable rates of finding and substantial levels of conventional reserve growth in older fields-indicate that the capability of the resource base to sustain production is yet considerable. The volume of domestic oil and gas production that is necessary in the national interest and the extent to which the resource base should be pursued are the central issues of public energy policy. 相似文献
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油罐内油品的加热与温度测试是实现油品温度控制的重要手段,也是实现国家石油储备体系中大型油罐安全运营的重要保障,因此,全面分析了大型油罐内油品加热技术及温度场研究相关成果.加热技术可分为整体加热与局部加热两种类型,应根据具体情况,结合油品性质、作业性质、地区及气温特点、安全因素等选择应用,其中节能环保型加热技术将越来越受关注.油罐温度场研究包括模拟计算、现场测试与模化试验3种方法,数值模拟方法具有一定难度,但可以节约成本,提供全面、准确的温度场结果;现场测试与模化试验在工程应用中存在一定局限性,但现阶段不可或缺,有必要积极采用新的测温技术.(表3,参41) 相似文献
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甘蓝型油菜特高含油量育种技术与资源创新 总被引:7,自引:0,他引:7
采用品种间单交、复交和生态育种,黄籽育种,DH系育种,高含油种质杂种优势育种等途径,将甘蓝型油菜种质材料含油量由40%左右提高到60%左右,最高达61.7%;杂交种的含油量由40%左右提高到50%以上。在高油杂优利用上提出"高油种质+化学诱导雄性不育"的杂交育种模式,比CMS、GMS杂交育种途径更高效、安全,并能更快地把高油种质应用到生产中去。笔者依据细胞生理和成分的分析以及向日葵育种的经验,提出油菜含油量可达70%左右,可能成为育种者今后奋斗的目标。 相似文献
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The basic concepts for thermochemical hydrogen generation processes have been summarized in this article. A useful set of criteria has been described for the screening and selection of potentially viable, multistep, closedcycle thermochemical processes for hydrogen generation. Three illustrative, new closed-cycle processes have been discussed, indicating potential, overall thermal efficiencies ranging from approximately 40 to 60 percent. Combined thermochemical-electrolytic schemes also warrant further consideration. Principal technical problems in the development of such thermochemical closed-cycle and mixed-cycle processes are expected to include primarily materials compatibility, reaction kinetics, separation techniques, and heat-exchanger systems. As natural gas supplies decline and prices rise, new open-cycle thermochemical processes based on water and other fossil fuel feedstocks will be the first important new technology in supplying the growing hydrogen needs of industry for at least the next two decades. Conventional electrolysis technology does not appear to be a competitor for large-scale supplies in this century unless very low off-peak electrical power rates become available, although electrolysis will be the best technique for some small-scale uses. Further analysis will be required to determine if closed-cycle thermochemical or mixed-cycle methods will displace electrolysis or other methods as the principal technology for the production of hydrogen on a large scale for the longer term. 相似文献
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西部开发工程为我国的天然气管道和焊管提供了巨大的发展机遇,西 东输的管网建设为制管行业提出了更新更高的要求,概述了我国油气输送管道的发展前景及对各类管道的要求,指出了我国目前轧钢和制管行业与国差距,认为冶金企业和制管企业对应生产机组设备,工艺技术,检测手段和生产能力进行更新,以管理工程的要求,促进西气东输工程的建设。 相似文献
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For the past three decades the quantity of petroleum (both oil and oil plus gas) found per foot of drilling effort in the United States for any given year can be expressed as a secular decrease of about 2 percent per year combined with an inverse function of drilling effort for that year. Extrapolation of energy costs and gains from petroleum drilling and extraction indicates that drilling for domestic petroleum could cease to be a net source of energy by about 2004 at low drilling rates and by 2000 or sooner at high drilling rates, and that the net yield will be less at higher drilling rates. 相似文献