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1.
介绍了 3种先进的连接管件成形技术 ,即小弯曲半径管内压推弯成形技术、球形管接头的胀形成形技术和管件的内径滚压成形技术 ,对其基本成形过程进行了描述 ,并通过铝合金、不锈钢和钛合金管件的成形试验获得了主要工艺参数对成形的影响规律 ,结果表明采用这些方法成形所需的连接管件是非常有效的  相似文献   

2.
二恶英类物质检测分析技术进展   总被引:2,自引:0,他引:2  
介绍了同位素稀释气相色谱质谱联用和生物快速检测法测定二恶英类化合物的技术进展,概述了国际通用的二恶英类标准分析方法体系,提出了各方法的适用范围,综述了我国二恶英类化合物分析研究现状并对我国二恶英分析检测提出了建议。  相似文献   

3.
浑河沈阳段“十一五”期间水体构成及污染来源分析   总被引:1,自引:1,他引:0  
李家玲 《环境保护科学》2012,38(2):40-42,93
介绍了浑河沈阳段"十一五"期间水体的构成,分析了其支流水质状况以及浑河沈阳段主要污染来源。结果表明,支流河是浑河补水的主要来源,污水处理厂尾水已成为支流河和浑河干流的主要补水来源,其中上游径流38%,污水厂排水8%及细河、蒲河、满堂河和白塔保河等5条支流河补水54%;浑河沈阳段污染源数量最多的是农业源,占浑河流域沈阳段污染源的55.33%;其次是生活源,占浑河流域沈阳段污染源的26.19%;再次是工业源,占浑河流域沈阳段污染源的18.43%;最少的是集中式污染治理设施,占浑河流域沈阳段污染源的0.05%。  相似文献   

4.
识别出动火作业所遵循的法律法规 ,利用工作危害分析方法对动火作业进行危害因素的辨识和风险评估 ,制定风险削减措施 ,降低风险。  相似文献   

5.
This paper presents a method to facilitate the decision-making process in selecting sustainable floors (elements) for buildings in Sri Lanka, taking into consideration environmental, economic and social assessments of materials used for these elements. Two types of elements are selected for this study, namely, tile and vinyl tile. Environmental burdens associated with these elements are analyzed in terms of embodied energy and environmental impacts that are relevant to Sri Lanka, such as global warming, acidification and nutrient enrichment. Economic analysis is based on market prices and affordability of materials. Factors considered for the social analysis are thermal comfort, good interior (aesthetics), ability to construct fast, strength and durability. It was found that tile elements are superior to vinyl tile elements on environmental scores if processes of complete life cycle of these elements are taken into account. On social score also, tile elements (104.8) are better than vinyl tile elements (51.15). But on economic score, vinyl tile elements are better. These scores are presented in a matrix which will help in selecting sustainable floor coverings for buildings.  相似文献   

6.
Many companies, government agencies and researchers have struggled with the question of how to allocate emissions for cogeneration systems. Some work has been performed, but the results obtained thus far, are not universally accepted, and are often inconsistent, overly complex and difficult to use, and are not based on sound reasoning. In this article, selected methods for allocating emissions for cogeneration systems are described and compared. In addition, exergy values for typical commodities encountered in cogeneration are presented. The reasoning behind this author's view is that the exergy-based method is the most meaningful and accurate of the methods.  相似文献   

7.
Traditionally, treatment of solid waste has been given limited attention in connection with life-cycle assessments (LCAs). Often, only the amounts of solid wastes have been noted. This is unsatisfactory since treatment of solid waste, e.g. by landfilling or incineration, is an operation, requiring inputs and producing outputs, which should be described in the inventory of an LCA, in parallel to other operations. However, there are difficulties in describing emissions from solid waste treatments and there is a need for development of such methods. In this paper an approach for describing emissions from incineration and landfilling is outlined. Methodological questions concerning the time-frame and allocation principles are discussed. Methods for estimating potential emissions from landfilling of municipal solid waste and industrial wastes are suggested. The methods are used for calculating potential emissions from landfilling of some typical wastes. These emissions are compared with the emissions from other stages in the life cycle for some materials and wastes. it is shown that the potential emissions from landfilling are, for some products, of importance for the final results. Hence, if emissions from landfilling are neglected, or underestimated, results and conclusions in an LCA may be misleading.  相似文献   

8.
An important consideration in the selection of potential replacements for CFs is the rate of hydrogen-atom abstraction by the hydroxyl radical. Approximate linear correlations are investigated that allow the prediction of the relevant rate constants for partially fluorinated hydrocarbons. These rate constants may used to infer tropospheric lifetimes. For fluorinated ethers, estimates are presented for important rate constants which have not yet been determined experimentally, and lifetimes are predicted. Differences between ethers and alkanes are discussed, and trends in the variation of lifetimes with the degree of fluorination are noted.  相似文献   

9.
采用泄漏检测与维修( LDAR)技术进行了全面检测和统计分析,分析泄漏的原因并通过维修减少泄漏。结果表明:芳烃抽提装置容易泄漏的元件主要为连接件和阀门,主要分布在泵区;SV≥5000μmol/mol的泄漏密封点占总密封点数的0.57%,对总泄漏量的贡献达到了82%,是造成泄漏排放的主要部分。设备管阀件泄漏造成的加工损失率为0.0009%,泄漏点停工维修修复率为83%,停工维修后整体泄漏率为0.03%;VOCs减排率为71%。  相似文献   

10.
Attack by tropospheric hydroxyl radicals results in much shorter residence times for hydrofluorocarbons (HFCs) than for the fully halogenated chlorofluorocarbons (CFCs). Empirical structure-activity relations, previously calibrated for HFCs containing two carbon atoms, are used with semi-empirical and ab initio calculations to provide realistic first estimates of tropospheric lifetimes of various chlorine-free HFCs and hydrofluoroethers (HFEs) containing three carbon atoms. The heavily fluorinated HFEs are of particular interest in that they are likely to possess thermophysical properties which are suited to a range of applications for which CFCs are currently employed. Many of the HFEs are predicted to have shorter lifetimes than HFC-134a (CF3CH2F), which is already in large-scale commercial production as an alternative refrigerant. Factors are identified which appear to favour short lifetimes for HFEs.  相似文献   

11.
Sampling and analytical methods have been developed to determine 20–40 trace elements plus sulfate in precipitation. Samples are collected on an event basis in polyethylene bags, and are then freeze-dried and analyzed by instrumental neutron activation. Concentration data are presented for 3 years' precipitation samples from southern Rhode Island. Elemental solubility data are presented for a smaller set of samples. Elemental concentrations vary seasonally: crustal and pollutant elements have maximum concentrations in summer, and marine elements have maxima in the winter. The data were collected for use in receptor modelling studies, and the four elements most useful as tracers for regional pollution sources (Se, As, Sb, and noncrustal V) are all well determined.  相似文献   

12.
指标变换值表示的空气质量评价的普适指数公式   总被引:1,自引:0,他引:1  
为了建立形式简单、普适通用的空气质量评价的普适指数公式,适当设定空气指标的参照值和指标值的变换式,使不同指标的同级标准值经变换后的标准变换值差异不大,而标准变换值的对数值的差异更小,从而可以认为用变换值表示的不同指标皆与某个指标"等效"。因此,用变换值表示的不同指标的某种类型的空气质量评价的指数公式都可以用该"等效"指标相应的空气质量评价指数公式代替。在满足一定的优化目标准则条件下,采用猴王免疫进化算法对公式中的参数进行迭代优化,分别得到优化后对基于空气质量标准(GB3095-1996)的7项空气指标皆适用的对数型幂函数、韦伯-费希纳定律、Γ型分布函数、污染危害S型函数、加权加和型幂函数及参数化组合算子等6个空气质量评价的普适指数公式。对公式的可靠性进行了理论分析,对其实用性进行了效果检验,其评价结果与其他方法评价结果基本一致,并与实际相符合。结果表明:空气质量评价的多种形式的普适指数公式皆具有形式简洁、计算简便和普适通用的特点。  相似文献   

13.
This paper aims to consider the total cost, including polluting environmental emissions, of imports from China to Europe of five valve components in aluminium, steel and iron. These are compared with locally produced alternatives to investigate whether internalising such external costs affects their price competitiveness. Seaborne trade represents 90% of international trade and is growing faster than the world’s economy, but marine pollution emissions are not reflected in market prices. Chinese aluminium, iron and steel production are about 2.5 times more polluting than their European counterparts, but this is also not reflected in prices. In this paper both types of extra emissions are calculated, valued and added to the cost of the components analysed, for comparison with locally produced alternatives. The locally produced components generally remain uncompetitive with Chinese imports for all likely values of external cost, except for heavy aluminium components under high external cost assumptions. The Chinese iron components analysed are simply too low in cost for European (in this case Spanish) equivalents to be competitive even allowing for environmental costs; while the stainless steel ones are so small and light that transport cost, even including externalities, is not significant. While these specific results are of limited generalizability, they provide insight into an issue of considerable and growing importance. Some suggestions are offered for further research.  相似文献   

14.
通过分析我国核事故应急体系在应急预案、应急指挥、应急救援、技术支持、应急演习等多方面的已有能力,学习国外核电强国的核应急管理经验,总结福岛核事故应急的经验教训,发现我国现有核事故应急体系存在的问题,并提出"十三五"期间我国核事故应急的主要对策和措施,以期为我国核事故应急体系建设提供科学的和系统的工作思路。  相似文献   

15.
Biosensoren     
By the combination of transducers (thermistors, selective electrodes, field-effect transistors, optical systems) with immobilized enzymes or antibodies specific sensors for biologically relevant substances are obtained. The construction, ranges, of linearity, response times and stability of biosensors are demonstrated. Examples are given for their application in clinical analysis and fermentation control. Finally limits and future possibilities are discussed.  相似文献   

16.
海河流域怀柔山地油松林生态系统N,P,S元素生物地球化学循环研究结果表明,生态系统氮素输入输出基本平衡。氮素、磷素在未来一段时间内将在植物凋落层中累积,硫则在凋落物层、土壤中累积。这种情况形成了城市郊区森林生态系统元素循环的独特特性。  相似文献   

17.
碱氨蚀刻废液处理方法研究   总被引:4,自引:0,他引:4  
论述了碱氨蚀刻废液处理方法的试验研究.研究包括碱法回收氢氧化铜,酸法回收胆矾和电解法回收金属铜等三种方法.  相似文献   

18.
大量的剩余污泥已经成为国内外污水处理行业亟待解决的问题,产生了各种污泥处理方法。污泥前置减量技术中的高级氧化方法主要是通过溶胞技术与污水处理工艺相结合,达到减少剩余污泥量之目的。介绍了这些方法的国内外研究进展,评述了其中存在的问题,指出了未来发展的方向。污泥前置减量化更符合污泥处理的发展要求,高级氧化方法在其中将会得到广泛的应用。  相似文献   

19.
城市非点源污染模型研究进展   总被引:15,自引:2,他引:15  
王龙  黄跃飞  王光谦 《环境科学》2010,31(10):2532-2540
回顾了城市非点源污染模型的发展历史,分析了能够模拟城市非点源污染的7个国外模型(SWMM、STORM、SLAMM、HSPF、DR3M-QUAL、MOUSE和HydroWorks)的特点、适用性和局限性,介绍了国外城市非点源污染模型不确定性研究方法和成果以及城市非点源污染分析概率模型,总结了国内城市非点源污染模型的研究成果.指出国外城市非点源污染模型在污染物累积和冲刷、泥沙和污染物运移、污染物的生化反应等方面模拟能力不足,而国内城市非点源污染模型多是经验模型,模拟面积较小,模拟精度较差.提出未来城市非点源污染模型研究应提高泥沙和污染物的模拟能力,探索无资料和不完全信息下城市非点源污染的模拟和预测,加强城市非点源污染随机性模型的研究,发展城市非点源污染模型与GIS的耦合应用.  相似文献   

20.
表面化学改性活性炭对有机物吸附的研究进展   总被引:6,自引:0,他引:6  
金璇  马鲁铭  王红武 《环境科技》2006,19(Z2):43-45
综述了国内外学者对氧化改性和还原改性活性炭吸附有机物的研究进展。氧化改性和还原改性活性炭的比表面积、表面官能团和表面pHpzc都发生了变化,因此对液态和气态有机物的吸附发生变化。吸附机理主要是通过改变三种力的作用形式和大小,即扩散力、供-受电子机制和静电作用。氧化改性活性炭不利于吸附水溶液中的有机物,还原改性活性炭有利于吸附水溶液中的有机物,氧化改性和还原改性活性炭都有利于吸附气态中极性有机物。  相似文献   

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