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排序方式: 共有1315条查询结果,搜索用时 312 毫秒
831.
本文针对郑州至石人山高速公路路面上面层施工的工程实践,论述了AC-13原材料的特点及质量控制要求,探讨了AC-13混合料的配合比设计方法,并总结了施工中的质量控制要点.该研究成果可为其他类似工程提供参考和借鉴.  相似文献   
832.
Alkali ash material (AAM) concrete is a unique material that is sustainable and cost-effective because it utilises waste fly ash, and has properties superior to other concrete products. The AAM concrete described here is produced from the addition of inexpensive chemicals to fly ash. AAM can be used to create a wide range of materials including high performance concrete (HPC-AAM) and lightweight (LW-AAM). The high performance AAM provides rapid strength gain along with high ultimate strengths of more than 110 MPa (16000 psi). LW-AAM can produce materials with densities ranging from 1200 to 2200 kg/m3 and compressive strengths from 2 (290 psi) to 65 MPa (9500 psi). Both HPC-AAM and LW-AAM have far better environmental resistance than Portland cement concrete, resisting attack from sulphuric acid (H2SO4), hydrochloric acid (HCl) and organic acids. AAMs resists freeze–thaw attack and high abrasion, possesses low chloride permeability and does not exhibit alkali silica reactivity.  相似文献   
833.
基于物质代谢的中国纺织业生态效率评价   总被引:3,自引:1,他引:2  
生态效率是衡量循环经济发展水平的重要指标,它同时考虑经济效益和环境效益,将可持续发展目标融入不同层面的经济活动.论文以物质代谢为基础,采用价值-影响比值法建立行业生态效率的度量模型,并提出行业经济模式评价概念模型.以我国纺织业为例,核算该行业能源和废物代谢以及物质代谢的生态效率.结果表明:随着我国纺织业的快速发展,能源与废物代谢通量呈现出增长势头,但生态效率不断提高.1996-2005年阐,我国纺织业工业总产值增加了2.68倍,能源效率和环境效率分别提高了1.80和1.88倍左右,生态效率提高了2.6倍.我国纺织业生态效率评估结果同时显示,1996-2005年期间纺织业经历了传统发展模式、末端治理模式,并开始向循环经济模式转变.虽然我国纺织业物质代谢的生态效率在提高,但是随着物质资源的日益稀缺,物质代谢的生态效率仍需进一步提高,而提高生态效率的关键是资源效率与环境效率的协同发展.  相似文献   
834.
Effective use of materials is one possible component of a sustainable manufacturing strategy. There are many such strategies proposed in the literature and used in practice, with confusion over what they are, what the differences among them may be and how they can be used by practitioners in design and manufacture to improve the sustainability of their product and processes. This paper reviews the literature on sustainable manufacturing strategies that deliver improved material performance. Four primary strategies were found: waste minimisation; material efficiency; resource efficiency; and eco‐efficiency. The literature was analysed to determine the key characteristics of these sustainable manufacturing strategies and 17 characteristics were found. The four strategies were then compared and contrasted against all the characteristics. While current literature often uses these strategy titles in a confusing, occasionally inter‐changeable manner, this study attempts to create clear separation between them. Definition, scope and practicality of measurement are shown to be key characteristics that impact upon the ability of manufacturing companies to make effective use of the proposed strategy. It is observed that the most actionable strategies may not include all of the dimensions of interest to a manufacturer wishing to become more sustainable, creating a dilemma between ease of implementation and breadth of impact.  相似文献   
835.
ABSTRACT

This paper quantifies construction and demolition waste (C&DW) generation rate in Indian cities using bottom-up material flow analysis approach. A dynamic model was applied to different classes of cities in India to investigate how C&DW generation rate varies across different classes of cities. The data on construction and demolition activities in different classes of cities were estimated from information reported in secondary literature. The results show that urban areas in India generated over 150 million tonnes of C&DW in 2016, and almost 50% of waste was generated in small to medium towns. The paper concludes with discussion on opportunities for recycling of C&DW and closing the material loops in Indian cities.  相似文献   
836.
Zinc is one of the most widely applied nonferrous metals in China. Study on the applications and recurrent situation of zinc resources is of great strategic importance for the sustainable development of China's economy. In this paper, a dynamic material flow analysis (MFA) method has been adopted to analyze quantificationally zinc resources in China, as well as to analyze and predict the quantity of zinc product scrap and their recycling situation. The weighted average method was applied to calculate average lifetimes of six major zinc products in China. The average lifetimes of battery, zinc oxide, zinc die-casting alloys, zinc material products, galvanized zinc and brass are 0.17, 5.3, 11.1, 12, 21 and 30 years, respectively. Assuming the lifetime of zinc product group obeys the Weibull distribution and the consumption of zinc products varies linearly with time, the future consumption and scrap generation of zinc products will increase continuously. It is expected that they would increase from 49% to 76% during 2004–2020, respectively. Assuming the recycling rate remains unchanged with time, the zinc old scrap index, both the theoretical and actual values, would continue increasing in China. The values are expected to reach 0.402 and 0.076 by 2020, respectively. Therefore, the regeneration resource of depreciated zinc is actually insufficient in China. According to the scenario analysis, the actual value of old scrap indexes is positively correlated with the recycling rate of zinc products. Because galvanized products are the largest consumption area of zinc products in China, the influence of their recycling rate on old scrap index is obviously larger than other zinc products. Through the analysis, this paper suggests that the increase of the recycling rate of zinc products could not only improve to a certain degree China's relative shortage of zinc resources, but greatly relive the supply pressure of zinc in the world.  相似文献   
837.
含硫油品储罐危险性研究   总被引:2,自引:2,他引:0  
考察不同铁氧化物经过不同时间硫化后生成的FeS的氧化性.氧化性越高,给储罐带来的危险性越大.实验结果表明,氧化倾向及危险性与硫化时间有关,并与FeS的生成方式有关.同一铁氧化物分别经0.5 h和6 h硫化后,后者硫化产物的氧化性要大.这是因为经长时间硫化,H2S气体不仅与表面颗粒分子发生完全反应,而且大量的H2S分子扩散到颗粒的内部,与铁氧化物内部分子充分接触发生反应,即硫化程度较完全,生成较多的FeS.同时说明,硫化时间越长,对储罐构成的威胁越大.经6 h硫化后产物的氧化倾向从高到低依次为Fe2O3、Fe3O4和Fe(OH)3生成的硫化产物.  相似文献   
838.
介绍了碳排放量核算的基本原理与通用方法。以某钢铁公司焦化厂CO2排放量计算为实例,对比分析了物料衡算法和经验计算法的合理性和准确性。研究发现,对于钢铁企业来说,采用IPCC方法进行CO2排放量的计算是可行的。  相似文献   
839.
利用外墙保温材料的小尺寸燃烧实验来研究外墙保温材料在火灾过程中的燃烧特性,分析总结外墙保温材料在火灾过程中的燃烧现象.建立外墙保温材料火灾实验模型,对外墙保温材料火灾实验的实验方法以及数据测定方式进行了介绍.采用不同阻燃性质的保温材料,研究阻燃成分阻止竖向燃烧的效果.观察不同的保温材料在燃烧过程中的点燃性能.根据材料的阻燃性能、点火位置、固定方式的不同,总结燃烧痕迹的变化规律.分析非阻燃材料在燃烧的过程中的熔滴生成,发现产生的熔滴对未燃保温材料的点燃现象.观察不同的保温材料在燃烧过程中的烟气生成及烟气层的形成.通过小尺寸火灾试验的方法来研究建筑外墙保温材料火灾的特性,提出使用阻燃型外墙保温材料的必要性.  相似文献   
840.
浅析进口原油安全技术说明书   总被引:1,自引:0,他引:1  
以原油这一具有危险品属性的战略物资作为研究对象,分析各国对原油进行MSDS登记的现状,对多种进口原油安全技术说明书进行分类归纳.介绍各国在危险品分类、健康环保、职业防护等多方面开展的工作,对照比较国内相应法规和标准体系,以期对我国石油产品安全技术说明书的编写工作有所助益.对进口原油中的有害物质组分依照职业卫生标准,进行了归纳,实现健康危险限值的快速核定.为我国进一步推行GHS制度,完善构建合理的危险化学品管理、法规、执行体系,在安全技术说观书这一领域提出相关建议.  相似文献   
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