影响危险化学品生产企业安全评价有效性的因素探讨

随着化学工业的迅速发展,化学品的产量和品种大幅增加,危险化学品生产企业各类事故频发,严重阻碍了化学工业的发展.为此,国家制定了一系列的法律法规,以期遏制恶性事故的发生.安全评价作为预防事故的重要手段,现已广泛应用于各个行业,危险化学品生产企业也不例外.但是,随着安全评价工作的开展,也暴露出与安全评价有关的一些问题.本文简要介绍了我国危险化学品生产企业的安全现状,详细分析了影响危险化学品生产企业安全评价有效性的各种因素,并提出了相应的对策措施.     

库水作用下公路土质岸坡稳定性影响因素综合评判

以三峡库区公路土质岸坡为研究对象,通过对库水作用的影响效应分析,建立了岸坡稳定性评价的参数指标评价体系以及相应的分级标准.在此基础上,应用影响因素综合评判方法,对实例岸坡进行了稳定性分级评价,评价结果与实际情况基本相符.     

中国居民潜在国内出游力的区域差异

运用因子分析法对中国居民潜在国内出游力的区域差异作了分析,得出影响国内居民出游力的因子包括区域经济发展水平与增长能力、区域居民收入和经济发展的外向性、行业从业结构、区域经济发展活力4个主要因子,并利用聚类分析法将中国居民潜在的国内出游力划分为5个层次.     

粤港澳大湾区典型潮间带环境多介质中Cd形态空间分布特征及其影响因素

在粤港澳大湾区典型潮间带开展了 14个站位同步采样和观测,分析各采样点表水、孔隙水、悬浮物和沉积物中Cd形态的空间分布特征,并结合环境因子采用统计分析方法探讨不同介质中Cd形态分布差异的影响因素.结果表明,各潮间带环境表水、孔隙水、悬浮物和沉积物中Cd含量范围分别为0.41～15.03 μg·L-1、0.41～27.5...     

Pollution characteristics of the recent sediments in the Hangzhou section of the Grand Canal, China

Spatial distribution of heavy metals, arsenic and organic matter in recent sediments in the Hangzhou section of the Grand Canal and their relationships were analyzed. The results showed that the concentrations of heavy metals and organic matters varied widely along the canal, and the average geological accumulation factors decreased in the following orders: organic carbon(2.6), zinc(2.1 ), cadmium(2.0), copper( 1.5), lead(1.1), nitrogen(0.9), mercury (0.8), phosphorus(0.4), arsenic(0.2) and chromium(0). Content of heavy metals and organic carbon in the top 10 cm layer were lower than that of lower layers, except for mercury and organic carbon in the S9 section. Contents of organic carbon in the top 50 cm layer of the mud sediments are significantly higher than those undemeath. In the bottom mud layer, there is a concentration peak of the pollutants. In the mud sediments of the canal, cadmium mainly occurred in the Fe and Mn oxide fraction, copper in the organic fraction, lead in the Fe and Mn oxide fraction, and zinc in the carbonate and the Fe and Mn oxide fraction.     

安顺市土壤pH空间变异及影响因素分析

探究土壤pH的空间分布特征及其变异规律,分析环境因子对土壤pH空间分异的影响,对安顺市山地复杂环境下土壤pH的精准管理和土壤资源的可持续利用具有重要意义.基于22 851个野外采样点,综合采用全局Moran's I指数、冷热点分析、半方差函数和克里金插值的方法,从不同角度揭示了安顺市土壤pH值的空间结构特征和分布规律,...     

磁种-磁滤技术处理污染河水的试验研究

采用磁种-磁滤技术处理广州市两条河涌的污染水,考察了磁种投加量、混凝剂用量、磁场强度和磁滤速度对出水浊度的影响,并确定了最佳试验条件。结果表明,该工艺对TP、SS和浊度的去除效果较好,去除率分别为96．2％、92．4％和93．9％,对CODCr有一定的去除效果,去除率为68．2％,但对NH4^ -N的去除效果较差,去除率仅为25％。     

工频磁场诱导人FL细胞膜EGF的受体聚簇及噪声磁场的干预

为了研究50Hz工频磁场对人源细胞膜表皮生长因子(epidermal growth factor,EGF)的受体聚簇现象的可能诱导作用及噪声磁场的干预,将人羊膜细胞FL(human amniotic cells)分别用EGF、不同强度(0.05、0.1、0.2、0.4mT)工频磁场、噪声磁场、工频磁场和噪声磁场叠加的复合场处理15 min后,用间接免疫荧光染色法标记,并用激光共聚焦显微镜观察细胞膜表皮生长因子(EGF)的受体的聚簇现象.结果表明,0.1、0.2、0.4mT工频磁场辐照FL细胞15 min可诱导细胞膜EGF的受体发生聚簇,但0.05mT工频磁场辐照时,细胞膜不出现EGF受体的明显聚簇.0.2mT噪声磁场则不能诱导细胞膜EGF受体的聚簇;当0.2mT噪声磁场与0.1、0.2mT工频磁场叠加后,可抑制工频磁场诱导的细胞膜EGF受体聚簇,但不能完全抑制0.4mT工频磁场诱导的细胞膜EGF受体聚簇.研究结果表明,一定强度的工频磁场能诱导细胞膜EGF受体的聚簇;其作用阈值在0.05～0.1mT之间;噪声磁场对工频磁场诱导膜受体聚簇的干预作用存在剂量-效应关系.     

天津市PM10中元素的浓度特征和富集特征研究

为了解天津市大气PM10中元素的浓度水平和污染元素的来源,在天津市布置了7个采样点,获得了风沙季、非采暖季和采暖季19个元素的监测数据。结果表明:Ni、Pb、Cu、Cr是PM10中的主要超标污染元素;K、Ca、Na、Mg、Al、Si、Fe、Ti等8种元素是PM10浓度的主要贡献率元素(92%);19个元素的富集系数风沙季明显低于非采暖季;Co、Cu、Zn、Br、Pb五个元素各季和各站的富集系数均大于10,人为源贡献大于自然源,是环境治理的重点元素。     

Assessment of grate sag inlets in a residential area based on return period and clogging factor

Storm in-sag inlets, which typically have inflow capture efficiency of 100%, can violate the allowable water spread criterion of roadways, thus slowing the traffic movement and contributing to accidents. This is especially evident during severe storms of high return periods and when a storm sewer inlet of grate type is adopted, because it is subject to debris and trash clogging factors. In this study, the water spread on pavement for in-sag grates located in a residential area in Kuwait is analyzed in terms of return period and clogging factor. It is found that for a single grate inlet with a return period of 10 years, a clogging factor of 50% can lead to a water spread value exceeding the local design constraint assigned for residential areas, which is one traffic lane of 4m width. It is also shown that for in-sag locations, a double-grate inlet is more preferable than the single one, because the former tends to reduce the adverse hydraulic effect of total inflow on water spread width. The effect of clogging factor on a multiple-grate inlet located in sag is determined from a simple expression suggested in this study.