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排序方式: 共有235条查询结果,搜索用时 977 毫秒
171.
对数据采集与监控系统(SupervisoryControlandDataAcquisition)技术的原理进行了介绍,对排水管网SCADA系统功能进行系统分析,并根据实践经验对SCADA系统的建立和应用提出了一些建议。 相似文献
172.
173.
本文简要叙述了建立三峡工程环境生态监测网络的必要性,以及它的主要职能和任务,并对监测的主要内容、监测网的组成、监测网成员单位的隶属关系等作了较详细的说明,同时建议把三峡工程环境生态监测中心设在重庆。 相似文献
174.
Development of maximum water recovery (MWR) networks for continuous processes based on Pinch Analysis has been rather well established. In contrast, less work has been done on the water minimisation problem for batch process systems. This work presents a two-stage procedure for the synthesis of an MWR network for a batch process system, covering both mass transfer-based and non-mass transfer-based water-using processes. The first stage of the synthesis task is to locate the various network targets, which include the overall and interval-based minimum utility targets (fresh water and wastewater flows) as well as storage capacity target using the newly developed time-dependent water cascade analysis (WCA) technique. In the second stage, a new tool called the time-water network is introduced to help in the development of the MWR network to achieve the established utility targets. This new network representation has an advantage of clearly depicting the time-dependent nature of a batch water network. 相似文献
175.
Water quality monitoring conducted routinely over time at fixed sites has been a part of most water quality management efforts for many years. It has been assumed that such monitoring plays a major role in management. However, the lack of routine data analysis, and reporting of information derived from such analysis, points up the fact that the exact nature of the role of routine, fixed-station monitoring is poorly defined.There is a need to very clearly define this role in the design of such systems if routine monitoring is to efficiently and effectively meet the information expectations placed on it. Design of routine monitoring systems will therefore have to consider not only the where, what, and when of sampling, but also why. A framework for including the why of monitoring in the design process is proposed and experience with using the framework in New Zealand is discussed. 相似文献
176.
为深入了解洞庭湖沉积物重金属污染现状及生态风险,采用欧共体物质标准局提出的BCR提取法分析29个表层沉积物中Cd、Cr、Cu、Pb和Zn的赋存形态,并应用基于重金属形态的RSP(ratio of secondary phase and primary phase,次生相与原生相分布比值法)和RAC(风险评价指数法)评价了沉积物重金属的污染程度与生态风险.结果表明:全湖范围内,Cd主要以弱酸溶解态为主,Cr主要以残渣态和可还原态为主,Cu以残渣态和可氧化态为主,Pb以可还原态和残渣态为主,Zn以残渣态和弱酸溶解态为主;RSP评价结果显示,Cd在全湖范围表现为重度污染,Pb总体表现为中度污染,但在湘、资、沅、澧"四水"入湖口以及东洞庭湖几个采样点表现为重度污染,Cr、Cu和Zn处于轻度污染和清洁水平;RAC评价结果表明,全湖范围内5种重金属生态风险排序依次为Cd > Zn > Pb > Cu > Cr,Cd表现为高等风险,Cu、Pb和Zn表现为中等风险,而Cr表现为低等风险.研究显示,在研究沉积物重金属总量基础上进行重金属形态分析,有助于深入了解重金属对环境的危害. 相似文献
177.
Martha Grabowski Premnath Ayyalasomayajula Jason Merrick John R. Harrald Karlene Roberts 《Safety Science》2007,45(10):1013-1043
A primary purpose in measuring safety is to develop intervention strategies to avoid future accidents. Recognizing signals before an accident occurs offers the potential for improving safety, and many organizations have sought to develop programs to identify and benefit from alerts, signals and prior indicators. In this paper, we address the challenge of identifying and evaluating leading indicators of safety in virtual organizations–organizations comprised of multiple, distributed members, temporarily linked together for competitive advantage, that share common value chains and business processes supported by distributed information technology. We begin by discussing risk propensity in virtual organizations and leading indicators of safety. We then describe a pilot study to identify leading indicators for one safety-critical system, and use the results of that study and the literature just described to propose an approach to developing leading indicators in virtual organizations. 相似文献
178.
基于通路法的通风网络最大流求解方法 总被引:1,自引:0,他引:1
最大流问题属于网络优化的范畴 ,在通风系统改造等方面具有重要作用 ,为此 ,笔者对网络最大流的算法进行了研究和探讨。利用图论和集合论的知识 ,结合通风网络特点 ,对通风网络最大流问题进行了深入研究 ,提出适合求解通风网络最大流问题的通路法。用通路法求解通风网络最大流时 ,用节点邻接矩阵 ,通过矩阵运算确定通路 ;通过对最小可增广通路 ,依次进行增广求得最大流 ,该方法简便快捷 ,易于程序实现。与Edmonds Karp修正算法相比 ,通路法具有运算量小的优点 ;与Dinic算法相比 ,通路法具有无需分层和无需确定向前边、后退边的优点。通路法对教学和科研具有重要意义和实用价值 相似文献
179.
根据污水厂日报表中的数据分别建立了ARMA、逐步回归分析、基于回归分析的神经网络模型和基于时间序列分析的神经网络模型,通过比较选择了基于时间序列分析的神经网络模型作为对污水厂出水COD的预测模型,其平均预测精度为85%,取得了满意的预测结果,有利于克服根据在线监测调整工艺参数的滞后性的缺陷,保证出水水质. 相似文献
180.
Motivation of Japanese companies to take environmental action to reduce their greenhouse gas emissions: an econometric analysis 总被引:1,自引:0,他引:1
To analyze the motivations of Japanese companies to take environmental actions to reduce their greenhouse gas (GHG) emissions,
we used FY2006 research data and questioned Japanese industries regarding their reduction of GHG emissions. Empirical investigations
revealed that voluntary targets set by industry organizations, government requirements, and advance responses to possible
future regulations can positively influence environmental actions for GHG emission reduction; however, cost reductions and
corporate social responsibility fulfillment cannot.
相似文献
Seiji IkkataiEmail: |