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81.
采用灰色关联度分析方法,对影响城市大气环境质量的因素进行了相关分析,并对呈负相关关系的影响因素关联度计算采取了倒数化算子处理,使计算结果更切合实际。 相似文献
82.
83.
研究了不同分析方法、去浊度手段和预处理方式对地表水总磷测定的影响。结果表明:钼酸铵分光光度法在跨界水体联合监测中较连续流动分析法、氯化亚锡还原光度法、孔雀绿-磷钼杂多酸分光光度法更为适用;在水样没有色度的情况下,采用浊度-色度补偿法和离心法都能有效消除浊度干扰,相对误差±10%;预处理方式的不同是导致各监测单位测定结果可比性差的最关键因素。 相似文献
84.
《Environmental Forensics》2013,14(3-4):331-340
Prince William Sound (PWS), Alaska has an extensive history of human and industrial activity that has produced a complex organic geochemistry record in subtidal sediments of embayments throughout the sound. In addition to contributions from recent oil spills and a regional background of natural petroleum hydrocarbons originating from active hydrocarbon systems in the northern Gulf of Alaska (GOA), pyrogenic and petrogenic PAH were, and continue to be introduced to subtidal sediments at numerous sites of past and present human activities. These sites include villages, fish hatcheries, fish camps and recreational campsites in addition to abandoned settlements, canneries, sawmills, and mines. A holistic approach is used to fingerprint and quantify hydrocarbon contributions from multiple sources in a sediment sample. It involves acquiring a comprehensive understanding of the history of the area to identify potential sources, collection of representative samples, and accurate quantitative analyses of the source and sediment samples for a suite of diagnostic PAH analytes and chemical biomarker compounds. Unlike the deepwater sediments of the sound and GOA, the TOC tool, described elsewhere, does not work as well in some restricted embayments due to their high contents of recent organic matter (ROM). The current study employs a constrained least-squares algorithm to allocate hydrocarbon sources contributing to subtidal sediments collected from PWS embayments in 1991, 1999 and 2000. Results show that sources contributing to the natural petrogenic background are present in the embayments, pyrogenic hydrocarbons including combustion products of diesel are important where human activity was high, and petroleum produced from the Monterey Formation (CA) is present locally. Oil and asphalt shipped from California were widely used for fuel and construction prior to development of the Cook Inlet and North Slope fields. In certain locations that were oiled in 1989, low levels of highly degraded Alaska North Slope crude oil residues attributable to the Exxon Valdez spill remain. 相似文献
85.
J. Christopher Young Zhen‐jian Chen 《Journal of environmental science and health. Part. B》2013,48(2):93-107
Abstract The total alkaloid content and individual alkaloid composition were determined by colorimetry and high performance liquid chromatography, respectively, for Canadian triticale and barley ergot (Claviceps purpurea). The total alkaloid content was highly variable between individual sclerotia from the same or different sources and ranged from 0.042 to 0.752% for triticale and from 0.082 to 1.04% for barley; average values were 0.239% for Ottawa triticale, 0.289% for Prairie triticale, and 0.264% for barley. Ergocristine and its isomer ergocristinine were the major constituents in both grains. On average, Canadian ergot pooled from rye, wheat, triticale, and barley consists of ergocristine (31%), ergocristinine (13%), ergocristinine (13%), ergotamine (17%), ergotaminine (8%), ergocryptine (5%), ergocryptinine (3%), ergo‐metrine (5%), ergometrinine (2%), ergosine (4%), ergosinine (2%), ergocornine (4%), ergocorninine (2%), and unidentified alkaloids (3%) and an average total alkaloid content of 0.236%. With the exception of rye and barley ergot from the maritime regions, Canadian rye, wheat, triticale, and barley ergot is fairly uniform in individual alkaloid composition. 相似文献
86.
M. Noble P. C. Oloffs R. So J. Yee F. Yuen 《Journal of environmental science and health. Part. B》2013,48(5):359-373
Abstract A tubular device has been developed making it possible to obtain layered samples of loosely aggregated, flocculent material from bogs or eutrophic lakes. The samples are up to 50 cm long and 15 cm in diameter. The sampler is free from protuberances and intact, layered samples can be taken. The tubular part of the sampler is about 85 em long, the walls of the lower 25‐cm portion harbouring a pneumatic closing mechanism which is controlled from above the water surface. An extendible handle for manipulating the sampler and for guiding it into place, is fastened to the upper end of the sampling tube. The performance and the operation of the sampler in the field are described. 相似文献
87.
基于开发需求的安徽沿江地区生态经济分区 总被引:1,自引:0,他引:1
从压力、状态和人类响应3个方面,构建了生态经济分区指标体系,结合经济开发需求的评价结果,以县(市、城区)为基本评价单元,利用主成分分析与系统聚类的方法,根据自上而下的专家定性评估,遵循空间邻近性原则,将安徽沿江地区划分为7个生态经济类型,即:合肥污染防治与城镇生态优化区、巢滁湖泊湿地保护与平原生态农业区、马芜铜宣工业污染防治与城镇生态优化区、宣南生态农业与水土保持区、安庆平原农业与湿地生态保护区、池州森林保育与生态农业区以及皖西水源保护与森林保育区. 相似文献
88.
Syed S 《Environmental monitoring and assessment》2007,130(1-3):311-322
‘Metal ash’ presents a waste disposal problem in most of the developing countries as the industries employ obsolete technologies.
In this paper we describe analysis of tin ash, zinc ash and aluminium ash by means of optical methods, such as X-ray diffraction
(XRD), inductively coupled plasma mass spectrometry (ICP-MS), electron probe micro analysis (EPMA), scanning electron microscopy
(SEM) and chemical methods. The results of tin ash obtained by XRD method matched well with the cassiterite, a naturally occurring
mineral of tin. ICP-MS studies reveal the presence of a large number of tracer metals, which may cause pollution by tertiary
dispersion and this aspect is discussed. Conversely, the data generated by chemical methods are limited. However, the methods
are simple and cost-effective. Then, they can easily be adopted by low-budget industries. Simple and cost-effective process
to recover tin from tin ash is described. It is based on heating tin ash with sodium cyanide to about 900°C to separate tin
component from the metal ash. The process recovers good quality tin and offers a very high yield. The process can be scaled
up to small pilot plant. 相似文献
89.
90.
从道路交通事故统计分析对比谈预防措施 总被引:11,自引:11,他引:11
笔者通过对比我国与世界上部分发达国家近十年来在道路交通事故方面的统计数据 ,并根据经济发展水平与机动车保有量的正比例关系及当前我国道路交通事故现状 ,分析得出道路交通安全事故的发生 ,与人、车辆、道路、环境信息及管理等因素具有密切关系 ,其中人 (尤其是驾驶员 )作为交通行为的主体 ,是道路交通事故诱因中一个关键性因素。由此 ,作者提出了要有效预防和减少道路交通事故的发生 ,必须将人、车、路、环境信息和管理等诸因素作为一个有机整体系统思考 ,且在未来的道路交通发展中应引入交通稳静化理念 ,以实现道路交通的安全、畅通与高效 相似文献