共查询到18条相似文献,搜索用时 125 毫秒
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根据广州市2004~2008年地表水环境监测资料,选取流溪河从化市温泉、流溪河山庄、太平三个监测断面,对水质状况和水污染趋势进行评价分析,结果表明:流溪河从化段近年来水质状况虽然持续良好,但各监测断面,尤其是下游断面,受有机污染日趋明显。 相似文献
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以汾河太原段为研究对象,采用稀释接种法对2003年—2008年太原段9个断面的5日生化需氧量(BOD5)进行监测,得到同一断面不同月份的BOD5值。发现,BOD5峰值出现的月份不同;在同一时间不同断面的BOD5值不同,其水质上游段较好,中游段次之,下游段较差。同时,根据年平均BOD5值对以上断面进行水质功能划分。其中,水库出口和上兰的水质均达到Ⅰ、Ⅱ类,胜利桥和迎泽桥的水质为Ⅴ类,其余断面水质都是劣Ⅴ类。表明,汾河太原段污染较严重,特别是在出现BOD5值最高峰的月份,应重点监测以及采取相应的措施。 相似文献
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按照水利部抗震救灾指挥部供水保障组的统一部署,水利部长江流域水资源保护局、黄河流域水资源保护局两支水质监测队伍13名技术人员,二台水质自动监测车及必要的监测设备已于5月18日到达灾区,协助四川省水利部门开展水源保护与水质监测工作。目前,水源地水质应急监测方案已初步商定,5个水源地,8个水源地上游河流控制断面已列为先期工作重点。5月19日上午,2台水质自动监测车已分别到达都江堰市水源地上游白沙河断面、成都市第六水厂水源投入监测工作。 相似文献
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乐安河水环境现状调查与保护对策 总被引:1,自引:0,他引:1
本文主要通过2004年丰水期、枯水期对乐安河13个断面的水质监测资料采用水质单因素标准指数法来分析乐安河水质现状,并由此提出治理水质污染和改善水环境质量的相应对策。 相似文献
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天津国际联合轮胎橡胶有限公司经过长期探索,自主创新,研制成功13.6R28,18.4R34,18.4R38,380/70R28五个规格普通断面以及70列大型拖拉机驱动轮子午线轮胎. 相似文献
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清水江流域总磷、氟化物污染现状分析 总被引:2,自引:0,他引:2
通过采用单因子评价法,选取2006~2009年实地监测数据,分析清水江水质现状。结果表明:清江流域总磷和氟化物总体呈降低趋势。2009年,除重安江大桥断面、湾水断面氟化物轻微超标外,其余断面均未超标,但各断面TP仍超标。 相似文献
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针对传统的多元统计监测方法不能有效检测工业过程中由于初始条件波动较大所引发的弱故障问题,提出一种基于多动态核聚类的核主元分析(DKCPCA)监控策略,实现多阶段间歇过程的弱故障在线监控.该方法首先针对过程中各阶段每一批次数据结合自回归移动平均时间序列模型(ARMAX)和核主成分分析(KPCA)方法分别建立动态核PCA模型,然后根据各批次模型间载荷的相似性采用分层次聚类方法进行聚类,最后将聚在一起的批次数据进行展开重新再建立动态核PCA模型,随着聚类数目的不同从而建立多个类模型.当在线应用时给出了多模型选择策略,以提高监测精度.将此方法应用于青霉素发酵过程的监控中,监测结果表明此方法取得了比DKPCA和MKPCA更好的监测性能. 相似文献
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介绍守护进程和Shell的基本概念及其特性,针对Linux集群下如何有效管理多台服务器,以监控Web服务器为例,设计了Shell脚本守护程序,并进行了验证测试,通过测试结果可以看出,该Shell脚本监控Web服务器是切实可行的,基本可以满足要求。 相似文献
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The effect of water coating of constituent monomers on the optical single-scattering properties of fractal soot aggregates is investigated numerically using core-mantle theory and approximations involving two effective medium theories. A cluster–cluster aggregation algorithm is used to numerically generate fractal aggregates, and the core-mantle Generalized Multi-particle Mie (GMM) method is used to compute the exact single-scattering properties of soot aggregates with water-coated monomers. Comparisons are then made with results obtained using approximations that combine either the GMM method or the Rayleigh–Debye–Gans (RDG) method with either the Maxwell-Garnett or the Bruggeman effective medium approximation (a total of four approximation methods). The optical properties calculated are the extinction and absorption cross sections, the single-scattering albedo, and the phase matrix of water-coated fractal aggregates; these calculations are done for two wavelengths, 0.628 μm and 1.1 μm. Water coating of the fractal aggregates is shown to increase the extinction and absorption cross sections, the single-scattering albedo, and forward scattering, but decrease backward scattering. The combination GMM + Maxwell-Garnett gives approximations that are quite good over a range of coating thicknesses and aggregate size. The combination GMM + Bruggeman performs less well, overestimating the extinction and absorption cross sections and underestimating the single-scattering albedo. In the case of RDG, the better combination is with the Bruggeman approximation, but the errors involved are greater than with the GMM + Maxwell-Garnett combination. Results from simple idealized calculations indicate that the differences between results with the Maxwell-Garnett and Bruggeman approximations should be even larger in cases of aerosol cores that are less absorptive than soot. Copyright 2012 American Association for Aerosol Research 相似文献
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Fábio B. Freire Gustavo N. A. Vieira José T. Freire Arun S. Mujumdar 《Drying Technology》2014,32(13):1524-1532
A number of contributions have been made in the field of chemical process monitoring and control with applications ranging from simple flow and temperature control to highly complex inferential adaptive control systems in biochemical and polymer production. These technologies face difficulties when applied to drying equipment, due to the inherent complexity of the operation. This article shows some recent trends in monitoring and control of drying processes. This review is organized in sections according to the transport phenomena involved in the operation of a dryer. In each section, examples of recent trends in monitoring and control strategies of key variables directly related to these transport phenomena are discussed. 相似文献
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For complex industrial processes with multiple operational conditions, it is important to develop effective monitoring algorithms to ensure the safety of production processes. This paper proposes a novel monitoring strategy based on fuzzy C-means. The high dimensional historical data are transferred to a low dimensional subspace spanned by locality preserving projection. Then the scores in the novel subspace are classified into several overlapped clusters, each representing an operational mode. The distance statistics of each cluster are integrated though the membership values into a novel BID (Bayesian inference distance) monitoring index. The efficiency and effectiveness of the proposed method are validated though the Tennessee Eastman benchmark process. 相似文献
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多向核独立成分分析(multiway kernel independent component analysis,MKICA)在监测间歇过程非高斯性和非线性方面取得了广泛应用,其仅仅是将线性独立成分分析(independent component analysis,ICA)方法利用核主成分分析(kernel principal component analysis,KPCA)白化扩展到非线性领域,但数据经KPCA白化后只考虑数据信息最大化未考虑数据簇结构信息的不足,为解决此问题,采用核熵成分分析(kernel entropy component analysis,KECA)代替KPCA白化的过程监测方法。该方法首先利用AT展开方法将过程三维数据变为二维数据;其次用KECA进行白化处理的同时解决数据的非线性;然后建立ICA监测模型用于非高斯生产过程监测;最后将该方法应用到青霉素发酵仿真和实际的工业过程并与MKICA方法进行对比,验证该方法的有效性。 相似文献