紫外光度法测定地表水中石油类的油标选择

精选了一种新油标。采用这种油标,可使紫外分光光度法测地表水中石油类的令人满意,省工省时。     

过氯乙烯滤膜采样-酸消解-钼蓝光度法测定磷酸雾

建立了过氯乙烯滤膜采样 -酸消解 -钼蓝分光光度法测定磷化车间磷酸雾的监测方法。实验室模拟采样的捕集效率为 95 7%～ 99 1 %。单个实验室对含 5μg和 1 5μg样品进行多次测定 ,其相对标准差小于 5% ,样品加标回收率为 98 2 %～ 1 0 0 5% ,方法检测限为 0 0 0 7mg/m3。对标样测定 ,结果均在给定值范围内。用该法与等离子发射光谱法(ICP)对 5个样品进行比对测定 ,结果均令人满意。     

中国21世纪城市供水新概念--分质供水

结合我国城市一直使用的统一给水方式已与当前水资源紧缺,用水多样化,人们饮用水质质化的状况极不适应的情况,提出对传统的给水方式进行改革的最适宜方式是分质供水。     

空气和废气监测中H2S标液的选择

有2种不同方法制备的H2S标准溶液进行测定,结果表明,所得标准曲线斜率一致,因此,在实际工作中可对其灵活运用。     

Sources and seasonal variation of PAHs in the sediments of drinking water reservoirs in Hong Kong and the Dongjiang River (China)

The main objective of this study was to investigate occurrence of polycyclic aromatic hydrocarbons (PAHs) in the sources of the drinking water supply of Hong Kong. The main emphasis was on the Dongjiang River in mainland China which is the major source, supplying 80% of the total consumption in Hong Kong (the remaining 20% is obtained from rain water). Sediments were collected from four sites along the Dongjiang River and four reservoirs in Hong Kong during both the dry and wet weather seasons. The concentrations of total PAHs in the sediments ranged between 36 and 539 microg/kg dry wt. The lower levels were detected at the upstream site on the Dongjiang River and at the reservoirs in Hong Kong (44-85 microg/kg dry wt), while the mid- and downstream sites on the Dongjiang River were more polluted (588-658 microg/kg dry wt). Examination of the PAH profiles revealed that the mid- and downstream sections of the Dongjiang River contained high percentages of 4,5,6-ring PAHs, similar to the amounts of atmospheric particulate matter and road dust collected during the dry weather season from the Pearl River Delta region as reported in the literature. Seasonal changes were revealed in the reservoirs of Hong Kong, with higher PAH levels in the wet weather season than in the dry weather season. For those reservoirs in Hong Kong that store water from the Dongjiang River, a distinct seasonal pattern was also observed, namely, that under dry weather season conditions the PAHs found in the sediments were primarily from petrogenic source, while under wet weather season conditions they were from pyrolytic sources. No such pattern was detected in the reservoirs which stored only rain water.     

完善环境影响评价公众参与的初步研究

环境影响评价制度是我国的一项基本环境保护法律制度,是环境管理体系的重要组成部分,完善公众参与体系有利于解决当前环境影响评价中公众参与存在的问题。在总结国内外公众参与发展进程的基础上,对完善公众参与体系进行了初步研究,提出了完善公众参与体系的内涵要点,提高公众参与体系研究力度,建立公众参与学相关内容。     

Survey of heavy metal pollution and assessment of agricultural soil in Yangzhong district, Jiangsu Province, China

We investigated concentrations of Hg, Cd, Pb, Zn, Cu, As, Ni, and Cr in samples of soil, cereal, and vegetables from Yangzhong district, China. Compared to subsoils, the sampled topsoils are enriched in Hg, Cd, Cu, Pb, Zn, and As. High levels of Cd and Hg are observed in most agricultural soils. Concentrations of Cr and Ni show little spatial variation, and high Cu, Pb, and Zn contents correspond well to areas of urban development. High As contents are primarily recorded at the two ends of the sampled alluvion. The contents of Cd, Hg, and total organic carbon (TOC) increase gradually to maximum values in the upper parts of soil profiles, while Cr and Ni occur in low concentrations within sampled profiles. As, Pb, Cu, and Zn show patterns of slight enrichment within the surface layer. Compared to data obtained in 1990, Cd and Hg show increased concentrations in 2005; this is attributed to the long-term use of agrochemicals. Cr and Ni contents remained steady over this interval because they are derived from the weathering of parent material and subsequent pedogenesis. The measured As, Cu, Pb, and Zn contents show slight increases over time due to atmospheric deposition of material sourced from urban anthropogenic activity. Low concentrations of heavy metals are recorded in vegetables and cereals because the subalkaline environment of the soil limits their mobility. Although the heavy metal concentrations measured in this study do not pose a serious health risk, they do affect the quality of agricultural products.     

薄膜涂覆过程中缺陷的形成及其防治措施的研究进展

薄膜缺陷会降低薄膜器件的使用性能,因此薄膜缺陷的产生机理和防治措施研究非常重要.综述了薄膜涂覆中缺陷的分类及其形成,分析了产生缺陷的影响因素,并对主要缺陷的防治方法作了总结.对防治方法进行机理分析,总结了去除非连续缺陷过程中的注意原则.结果表明,薄膜缺陷分为连续性缺陷和非连续性缺陷,连续性缺陷最重要的影响因素是表面溶液的蒸发和表面张力的变化,可以通过设计涂覆溶液和涂覆模具最大程度地避免.非连续性缺陷中最主要的缺陷是气泡和杂质,气泡可以通过去气和去泡两种方式去除,杂质可以过滤去除.研究表明薄膜涂敷中缺陷防治需要从试验和数值计算着手,结合理论研究探讨产生缺陷的内在机理.     

液体推进剂公路运输泄漏风险的模糊综合评价

针对液体推进剂在公路运输中泄漏事故发生的多样性、复杂性和不确定性等特点,建立公路运输偏二甲肼(UDMH)的泄漏事故模型.通过层次分析法确定各影响因素的权重,运用模糊综合评价思想对液体推进剂在公路运输中的泄漏风险进行了评价.结果表明,液体推进剂在公路运输中的泄漏风险为第2等级,风险较大;其影响因素中安全管理所占的权重最大,其次为运输设备状况、人员素质、运输中充装过量和路况,相关单位可依此排序制定预防措施.     

气体二氧化氯对葡萄表面细菌杀菌规律研究

研究气体二氧化氯杀灭金黄色葡萄球菌、大肠杆菌、李斯特单增菌和腐生酵母菌4种葡萄表面的危险致病菌的杀菌规律。在实验范围内,随着气体二氧化氯浓度的增加和杀菌时间的延长,杀菌效果明显增加。当杀菌时间超过12min,杀菌量级几乎不再增加。杀菌效率随温度的增加而减小,在实验温度条件下,只有大肠杆菌的杀菌效果减少了5.38～6.09log量级,其他3种菌均减少了6log量级以上,杀菌作用温度在实验条件下对杀菌效果影响不大。研究表明,当气体二氧化氯的杀菌浓度为25mgl-1、杀菌时间12min、杀菌温度25℃的条件下,金黄色葡萄球菌、李斯特单增菌和腐生酵母菌均减少了6.4log量级以上,而大肠杆菌达到5.76log量级;同时表明二氧化氯气体的杀菌保鲜功能也是食品安全技术非热杀菌手段。