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1.
对一种新型的温湿度调节器──PCTH-3温湿度调节器的输入和输出功能、显示功能以及操作方法作了详细的介绍,并对该调节器在交变湿热试验箱和温度变化试验箱上的应用作了较详细的举例。  相似文献   

2.
随着全球化的气候问题日益严重和“低碳革命”的兴起,低碳物流已成为现代物流业发展的必然趋势.结合国内外学者对低碳物流的研究文献,从物流过程的碳排放测量、物流环节的低碳控制、物流系统的低碳设计方面系统回顾了国内外学者在低碳物流领域的研究成果,梳理了低碳物流的发展历程,并对现有的研究成果进行了分析,以期为相关学者的后续研究提供思路.  相似文献   

3.
根据环境物流定义,提出环境物流部门是联系生产部门和新产品生产部门纽带的观点,利用投入产出矩阵思想,构建环境物流的投入产出模型。以2010年《辽宁省统计年鉴》和2007年42个部门投入产出表中的有关数据为基础,运用环境物流投入产出模型,估算并分析了辽宁省2007年环境物流的投入产出表。结果表明,发展环境物流业对经济、社会和环境的可持续发展具有深远意义。  相似文献   

4.
尖点突变模型在环境领域中的应用研究   总被引:1,自引:0,他引:1  
戚杰  胡汉芳 《环境技术》2005,24(3):24-26
突变理论是一种利用动态系统的拓扑理论来构造自然现象与社会活动中不连续变化现象的数学模型,其为现实世界中的突变现象提供了可利用的数学框架和工具。本文通过利用尖点突变模型来研究某省环境保护投资额的突变现象,得出环保投资额的突变条件,并推测出投资额突变背后的深层诱因。  相似文献   

5.
周琼芳 《环境技术》2000,18(4):10-13
将灰色关联分析引入环境技术的研究之中,为环境技术的研究提供一种新的分析技术。通过举例具体说明灰色关联分析在环境技术研究之中的应用,分析结果可对材料、产品的选用提供参考依据。  相似文献   

6.
灰色关联和逐步回归分析在环境试验研究中的应用   总被引:1,自引:0,他引:1  
用灰色关联分析方法,分析了贮存在漠河,海南,江津的GD3545,GD3537两种硅橡胶的拉伸强度随时间变化的关联度,得到了三地两种硅橡胶的拉伸性能顺序。用逐步回归法找出了影响硅橡胶拉伸强度的主要因素是时间,其次是温度,湿度。  相似文献   

7.
生鲜农产品冷链物流是云南省建设面向南亚、东南亚区域冷链物流中心的一个十分重要的组成部分,因此研究云南省欠发达地区生鲜农产品冷链物流存在的问题及其解决对策具有重要的意义.通过实地调研和访谈,得出云南省欠发达地区生鲜农产品冷链物流中存在产量分布不均、路况差、冷链设备运行和维护困难、冷储前预处理不合理等几大问题.在此基础上,提出借助物流选址理论科学选址,提高设备通过复杂路况能力,建立总公司技术人才定点帮扶制度,加强农产品预处理和预包装等多项对策措施.  相似文献   

8.
尝试用德尔菲法归纳建德市的主要环境问题,对15位专家的2轮咨询结果进行统计分析,筛选出15个指标组合成10个主要环境问题,较好地反映了建德市的环境污染现状和变化趋势。  相似文献   

9.
给出了处理环境优化问题的一种改进基因算法,并通过实例对该法与传统优化方法进行了比较,结果表明,该法直观,简便,适应性强,是一种优秀的非线性优化方法。  相似文献   

10.
《资源开发与市场》2004,20(6):414-415
由于因子分析法对解决多指标问题具有良好的适用性,可用于资源与环境可持续发展的综合评价,因此利用江苏省近年来的数据进行了实证分析,并提出了对策和措施以进一步推进江苏省资源与环境的可持续发展.  相似文献   

11.
Flows of chemical substances need to be managed in a sustainable way. Sustainable development as a whole and the sustainable management of substance flows in particular are both time issues. These include the importance of the dynamics of substance flows and the way these interconnect with the use of resources, the avoidance of environmental pollution, and their effects on health and food production. Another prerequisite for the proper management of substance flows is justice within and between generations. This requires a systematic approach and a systematic analysis of the issues as well as of the actions to be taken. One tool for such a systematic approach is temporal analysis. It brings the temporal aspects of the substances themselves and of their intended use, as well as factors affecting the stakeholders, such as decision makers, producers and consumers, into focus. In the past, timing factors were rarely taken into account. Knowledge of the temporal dynamics of substance flows and their resultant outcomes, as well as of their interaction with ecological, economic and social systems, is a basic requirement for successful substance flow management. The need to include temporal aspects into substance flow management and how to do so is outlined here. Included are not only politicians but also practitioners and scientists who must explicitly take into account adequate time scales, points in time, breaks and other forms of time in planning and acting.  相似文献   

12.
The method of flow analysis, which is similar to economic input-output analysis, is presented as a means of making flow models of ecological systems more useful to environmental managers. This paper considers as an illustration the extent to which nitrogen fertilizer added toSpartina salt marsh sediments can enhance shellfish growth. Nitrogen flow models of both the Barataria Bay salt marsh complex of coastal Louisiana and the Sippewissett Marsh of western Cape Cod are analyzed. The analysis shows the transfer of added nitrogen to shellfish growth viaSpartina growth, decomposition, and detrital feeding to be considerably less efficient than its transfer toSpartina growth itself. These results are similar for both marsh systems, despite their great physical differences and despite the inclusion of considerably more microbial processing of nitrogen in the Barataria Bay model than in the Sippewissett models. The results suggest that the most efficient mechanism by which added nitrogen could enhance shellfish growth in salt marshes may have to bypass the route through theSpartina life cycle.  相似文献   

13.
Geographic and substance use data were collected from 301 urban adolescents to compare the perceived and observed risk and safety associated with their home and activity space locations (routine locations). The geographic characteristics of the neighborhood surrounding each location was summarized according to features theorized to be risky, such as criminal activity and alcohol sales, and features theorized to be safe, such as recreation centers and churches. Data on socioeconomic status, derived from U.S. Bureau of the Census data, were also used to characterize locations. Adolescents' homes were typically perceived as safe despite observed measures of risk such as density of crimes and proximity to alcohol outlets. This held for both substance users and non-users. Differences in geographic characteristics for safe and risky activity spaces were observed for both substance users and non-users, with non-users appearing to be more sensitive to the presence of risky characteristics in the environment than substance users. Results highlight the need and provide a methodology to collect fine-grained activity space data instead of relying only on home residence when attempting to represent place and health behaviors with urban youth.  相似文献   

14.
陈莉娥 《四川环境》2007,26(3):25-27
该文在对合成洗涤剂废水进行混凝反应实验基础上,针对影响因素影响力大小的不同问题,使用主分量分析方法。对输入输出权矩阵进行处理和分析,对各影响因素影响力大小顺序进行了研究。分析结果表明,跟传统经验吻合较好,更重要的是对影响因子赋权方面提供了有力的理论依据,对混凝反应的理论分析于实验设计提供了新的思路。  相似文献   

15.
The flows of paper are analyzed throughout the papermaking processes, with the year 2007 and Korea defined as the system boundaries. In practice, the statistical data on the production, import and export of paper or pulp can be collected with relative ease from the government and industrial associations. However, the input data regarding the volumes of pulp and wastepaper used in different paper products, such as newsprint, printing papers, sanitary and household papers, specialty papers, and corrugating board base, are difficult to obtain because such information is generally kept confidential in the course of corporate operations.The production processes of paper products in Korea are modeled using information on raw materials, their compositions and production yields of products in order to identify and quantify the amounts of pulp and wastepaper used in each paper product. The material flows of paper are then analyzed based on the calculation model derived from the correlation of input and output flows between the individual processes throughout the entire paper lifecycle. Accuracy analysis using both mean absolute error (MAE) and mean absolute percent error (MAPE) is conducted to verify the amounts of pulp and wastepaper calculated from the proposed model against the volumes of domestically consumed pulp and wastepaper provided in the national statistics. Although the calculated values for the past (i.e., the 1980s and 1990s) differ to some degree from the statistical values, the data for the 2000s have a relatively higher level of accuracy, with the MAPE of the total pulp and recycling volume at 5.39% and 5.30%, respectively, thus validating the adequacy of the proposed modeling method. The proposed calculation model can be effectively used in the material flow analysis (MFA) of paper to reduce the burden of data collection and obtain relatively accurate results.  相似文献   

16.
The application of potassium ferrate for sewage treatment   总被引:12,自引:0,他引:12  
The comparative performance of potassium ferrate(VI), ferric sulphate and aluminium sulphate for the removal of turbidity, chemical oxygen demand (COD), colour (as Vis400-abs) and bacteria in sewage treatment was evaluated. For coagulation and disinfection of sewage, potassium ferrate(VI) can remove more organic contaminants, COD and bacteria in comparison with the other two coagulants for the same doses used. Also, potassium ferrate(VI) produces less sludge volume and removes more contaminants, which should make subsequent sludge treatment easier.  相似文献   

17.
超临界水氧化(SCWO)在环境保护中的应用   总被引:8,自引:0,他引:8  
超临界水氧化(SCWO)技术是近年来发展起来的新技术,利用它可以完全破坏有机毒害物质,在环境保护方面具有广阔的应用前景。文章在阐述超临界水性质的基础上,介绍了超临界水氧化法破坏有机物的优点,原理及工艺流程,并对该技术在应用过程中可能出现的问题及应当采取的措施进行了讨论。  相似文献   

18.
Aggregate is used in road and building construction to provide bulk, strength, support, and wear resistance. Reclaimed asphalt pavement (RAP) and reclaimed Portland cement concrete (RPCC) are abundant and available sources of recycled aggregate. In this paper, current aggregate production operations in Virginia, Maryland, and the District of Columbia are used to develop spatial association models for the recycled aggregate industry with regional transportation network and population density features.The cost of construction aggregate to the end user is strongly influenced by the cost of transporting processed aggregate from the production site to the construction site. More than 60% of operations recycling aggregate in the mid-Atlantic study area are located within 4.8 km (3 miles) of an interstate highway. Transportation corridors provide both sites of likely road construction where aggregate is used and an efficient means to move both materials and on-site processing equipment back and forth from various work sites to the recycling operations.Urban and developing areas provide a high market demand for aggregate and a ready source of construction debris that may be processed into recycled aggregate. Most aggregate recycling operators in the study area are sited in counties with population densities exceeding 77 people/km2 (200 people/mile2). No aggregate recycling operations are sited in counties with less than 19 people/km2 (50 people/mile2), reflecting the lack of sufficient long-term sources of construction debris to be used as an aggregate source, as well as the lack of a sufficient market demand for aggregate in most rural areas to locate a recycling operation there or justify the required investment in the equipment to process and produce recycled aggregate.Weights of evidence analyses (WofE), measuring correlation on an area-normalized basis, and weighted logistic regression (WLR), are used to model the distribution of RAP and RPCC operations relative to transportation network and population distribution data. The models can be used on a regional scale to quickly map the relative site suitability for a RAP or RPCC aggregate recycling operation in a particular area based on transportation network and population parameters. The results can be used to identify general areas to be further evaluated on a site-specific basis using more detailed marketplace information. As transportation or population features change due to planning or actual development, the models can be easily revised to reflect these changes.  相似文献   

19.
The aim of this paper is to evaluate two agroindustrial productive processes in their entirety (one organic and one semi-industrial), focusing on the comparison of impacts derived from the inputs and outputs of the system (life cycle assessment, LCA), integrated with a physical evaluation of the resources and natural services, on a common basis (emergy). Methods based on the joint use of LCA and emergy evaluation are useful, as they measure the contribution of environmental services and products to the productive process thus focusing primarily on the environmental impact of emissions and non-renewable energy inputs. The complementarity of the methods used in this paper contributes important elements and information useful for the comprehension of the organization of agriculture within Siena's territory. The results show important elements and useful information: (1) for the comprehension of the two agroecosystems' organization; (2) for the use of the energy flows that determine their development. Moreover, the combined use of emergy and LCA gives a comparative thermodynamic performance evaluation between organic and semi-industrial farming.  相似文献   

20.
Nowadays microbial fuel cells (MFCs) are a rapidly evolving field and studied extensively because of their simultaneous dual functions of decomposing organic waste matter and eco-power generation. Now, facing their low power density, multiple effects including various gravity conditions ranging from 0 G to 2 G and three kinds of geometric flow channel (serpentine channel, serpentine tapered channel and bio-mixer channel) in MFCs were studied because of their ability to significantly impact the performance of MFCs.Numerical simulation technology, with its significant lessening of time needed and saving experimental costs required was used in this study. Results show that a better power performance was found at a condition of 0.125 G and Reynolds number Re = 41.3 regardless of flow channel in MFCs. In addition, the bio-mixer channel of the flow channels in MFCs will have a better performance than the other two channels because of its lower pressure drop and higher power generation. These findings will provide useful information on enhancing the performance of MFCs, especially with the application of low gravity conditions in the future.  相似文献   

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