共查询到20条相似文献,搜索用时 31 毫秒
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DevelopmentoftheprocedureforthestabilizationofrainwatersamplesYuanZhongxin;Chung-ShinYuan(DepartmentofChemicalEngineeringNati... 相似文献
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石油化工行业各类储油罐,由于检修改装、换装油品、淤渣沉积严重等原因,影响油罐的正常使用时,都需要进行清洗作业.清罐作业是石油库的一项重大作业,清罐周期一般为3~5 a.如果对油罐进行清洗作业缺乏经验或安全措施不落实,极易发生火灾、爆炸、中毒、窒息等事故. 相似文献
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The Science of Nature - 相似文献
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《Journal of Cleaner Production》2007,15(6):525-537
Mankind is committed to taking sustainable pathways in search of a state of sustainability. Thirty years after the “Limits to Growth” published by the Club of Rome the world is still far from the equilibrium of sustainable development (SD). Technology is postponing the depletion of natural resources but is not solving the problem itself, either because the technology is itself not sustainable or because the application of it is being mismanaged. This article attempts to analyze the wide gap between the strategies drawn up and the effectiveness of the actions taken in implementing sustainability. The paper addresses the issue of whether or not mankind can make the right choices and has the right infrastructure of pathways to do so. In short, an answer is sought to the question, “What are the prerequisites for the fastest rate of sustainable change?” This question is tackled by the four authors. They start from critical arguments concerning the effectiveness of sustainable change, explain the terminology used in the article and identify the main factors for increasing the rate of sustainable change, which are then discussed in detail in each part of the text (EG). Then, each from a different starting point, they comment on self-organization (US), sustainable innovation and cultural regions (HK), global cooperation and regional resources (MB) and sustainable research by universities (EG). The individual contributions, when taken together, form a discussion of the crucial factors or prerequisites for sustainable change. It is concluded that only cooperation between regions and regional stakeholders can give sustainable change the driving force needed to overcome global (political) friction and ensure that it moves forward in equilibrium and at a constant rate. Specific measures are put forward to maximize awareness within and among regions. 相似文献
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用密切值法进行海域有机污染物优先排序和风险分类研究 总被引:4,自引:0,他引:4
将密切值法应用于大连湾海域有机污染物优先排序和风险分类研究是一种新的尝试 ,首先将大连湾海域有机污染物各评价指标 (污染物的毒性、在环境中的暴露情况和在水环境中的迁移转化 )的极端情况组成最优和最劣样本 ,再求可综合反映与最优和最劣样本距离两者水平的参数—密切值 ,并根据各污染物最优 (劣 )密切值的大小进行排序 ,根据最优 (劣 )密切值的突变来进行分类分析。实例计算结果表明 ,密切值法用于海域有机污染物优先排序和风险分类切实可行 ,而且不需要确定隶属函数、白化函数等主观参量或函数 ,评价结果更客观和可靠。 相似文献
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根据火焰原子吸收分光光度法测定水中的铜含量,分析主要的测量不确定度来源,即标准曲线不确定度、标准溶液不确定度、测量重复性不确定度.计算得到水中铜的测定结果的合成不确定度为0.098mg/L,扩展不确定度为0.196mg/L. 相似文献
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Hans Kuhn 《Die Naturwissenschaften》1976,63(2):68-80
In an attempt to understand the origin of living systems we encounter the following problems: How can we conceive the origin of the first self-reproducing forms, and by means of what stimuli could a constant increase in the complexity of such forms commence? How can a translation apparatus for genetic information develop? One cannot that such an apparatus for the synthesis of enzymes can function alone without the interference of enzymes themselves, which, however, could only become available after the construction of the apparatus itself. What stimulus mechanism is conceivable that leads to the division of the genetic apparatus into a replication system, and an enzyme-synthesis system?The main problem therefore, is not the search for basic theoretical concepts. It is not a question which can be answered by means of specific experiments. One should rather explore the principal possibilities of how molecules combine to produce more and more complicated functional units. We look for the fundamental structural changes in the organizational systems and the driving forces initiating these developments. Questions concerning the detailed chemical realization are of secondary importance. In trying to solve the puzzle of how the genetic apparatus is gradually built up as complex aggregates of molecules, we consider a consistent causal chain of simple and transparent physicochemical model steps. 相似文献
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UK Press office:01767 681577Out of hours:01767 681577Northern Ireland:028 9049 1547Scotland:0131 311 6505Wales:029 2035 3007E-mail:grahame.madge@rspb.org.ukhttp://www.rspb.org.uk/
鸟类保护协会(Society for theProtection of Birds) 1889年2月年成立于加拿大的迪兹伯里,由RobertWilliamson Hon女士担任该组织的第一任秘书长,Montagu Sharpe任第一届主席。1904年,该组织在维多利亚女王的支持下正式更名为"皇家鸟类保护协会"。 相似文献
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