大气压力对细水雾灭火系统泵组流量特性及效率的影响

柱塞泵是泵组式细水雾灭火系统的关键部件,它是细水雾喷头实施喷雾的供水源和压力驱动源.为研究大气压力,特别是高海拔低气压环境对柱塞泵流量特性及效率的影响,通过在合肥及拉萨两地的对比试验,给出了环境压力与柱塞泵流量特性及效率的关系.结果表明,大气压力减小使柱塞泵的流量减小,因此,在高原低气压环境下使用柱塞泵,应采用增加柱塞泵进口压力的措施,以保证泵组式细水雾灭火系统的设计性能;不同大气压力下泵组的效率无明显变化,即大气压力对泵组的效率无明显影响.     

含溴氨酸体系中菌株NAX的生长及其吸附特性

从污染土壤筛选到的菌株NAX能在含溴氨酸的体系中生长,并能吸附溴氨酸。随碳源浓度的增加,菌体生长旺盛。体系中高浓度的溴氨酸和盐度抑制菌株生长。菌株对溴氨酸的吸附等温线数据用改型的Pearl生长模型拟合比用Freundlich方程好。这意味菌株吸附溴氨酸存在多层吸附机理。     

兰州市空气污染物的变化规律与特征

论述了兰州市 1 993～ 1 996年间 ,室内外空气污染物 ,特别是一些非常规监测指标 ,如 PM1 0 、PM2 .5～ 1 0 和 PM2 .5 的污染规律和分布特征。结果表明兰州市仍以尘污染为主 ,PM1 0 在 TSP中平均占 3 3 %左右 ,而 PM2 .5 占了 PM1 0 的大部分     

兰州市气溶胶中金属与非金属元素的污染规律

通过对兰州市空气飘尘中粗、细颗粒物上化学元素的分布规律与特征的分析 ,指出了细颗粒物 (PM2 .5 )是一些有毒有害元素的主要携带者。这是可以在肺泡沉积 ,并能直接进入血液循环 ,对人体产生危害的重要部分     

兰州市空气污染对儿童及其父母呼吸系统健康的影响

叙述了居住环境对儿童和儿童父母亲呼吸系统健康影响的研究结果。揭示了儿童对空气污染所引起的呼吸系统疾病的急性反应较成人更敏感。吸烟合并空气污染更能损害人的健康     

还原-光度法测定空气中二氧化硫

在 pH 5 0～ 6 2、甲醛 -邻苯二甲酸氢钾介质和沸水浴中 ,微量二氧化硫能迅速还原三价铁为二价铁 ,使生成的邻菲口罗啉 -铁 (Ⅱ )铬合物量增加 ,导致溶液颜色变深 ,据此测定二氧化硫的含量。方法测定范围为 0mg/L～1 4mg/L ,检测限为 0 4mg/L。用于测定空气中二氧化硫 ,获得了满意的结果     

Distribution of endocrine disruptors in the Mondego River estuary, Portugal

Recent studies in the Mondego River estuary demonstrated signs of pollution in the area, but the nature of the contamination remains unexplored. Because there seems to be any studies in that zone checking for the simultaneous presence of xenoestrogenic endocrine disrupting compounds, either of animal (estradiol and estrone), vegetal (daidzein, genistein and biochanin A), pharmaceutical (17alpha-ethynylestradiol) or industrial (bisphenol A, 4-octylphenol, 4-nonylphenol) origins, the main objective of this study was to investigate their presence, in every year season and at eight points along the estuarine gradient. For this propose, water samples (2 L) were collected in high and low tides, preconcentrated in the Oasis HLB cartridges and cleaned in silica cartridges before their analysis by HPLC-DAD and GC-MS. The current data showed the absence of contamination by animal or pharmaceutical estrogens and by alkylphenols, but demonstrated the presence of high levels of phytoestrogens (up to 1.1 mug/L) and of bisphenol A (up to 880.0 ng/L). Because these two chemicals existed in high environmental concentrations in the most upstream sampling station, and taking in account that these pollutants may additively contribute to endocrine disruption, namely on fish, it was concluded that at least this particularly area of the Mondego estuary deserves continuous monitoring programmes.     

太湖水质参数中小尺度空间结构特征

经济的发展和人们生活水平的提高，造成了太湖的富营养化和生态环境的严重破坏。太湖的水质污染目前已严重影响了整个流域的可持续发展，并对人们的身体健康造成潜在的危害。治理太湖、保护太湖已成为人们刻不容缓的任务。了解湖泊水质参数空间结构特征是进行太湖环境评价的重要前提，也是合理治理太湖的重要基础。地统计学的出现为精确描述湖泊水质参数空间结构提供了有效的工具。应用地统计学技术对太湖3种水质参数进行了空间结构分析，结果显示，污染物集中在湖岸线附近不易向湖中央扩散，各水质参数空间分布差异性较大，且空间结构特征极为相似，不同尺度之间有差异性。同时，由于采样密度和范围的限制，更细微和更大尺度的空间结构特征尚不能得以表述。最后，还讨论了太湖水质参数的空间结构变异性。     

Characterization and distribution of polycyclic aromatic hydrocarbon in sediments of Haihe River, Tianjin, China

In this study sediment samples were collected from 13 sites of Haihe River in Tianjin City, China, sixteen of priority polycyclic aromatic hydrocarbons （PAHs） listed in USEPA were analyzed by means of GC-MS. The total concentrations of PAH ranged from 774.81 to 255371.91 ng/g dw, and two to four rings of PAHs were dominant in sediment samples. Molecular ratios, such as phenanthrene/anthracene, fluoranthene/pyrene and low-molecular-weight PAH/high-molecular-weight PAH, were used to study the possible sources of pollution. It indicated a mixed pattern of parolytic and petrogenic inputs of PAHs in sediments in Haihe River. The petrogenic PAHs may be mainly derived from the leakage of refined products, e.g., gasoline, diesel fuel and fuel oil vehicle traffics or gas stations from urban area. The pyrolytic PAHs might be from the discharge of industrial wastewater and the emission of atmospheric particles from petrochemical factories. In addition, the levels of PAHs in the urban and industrial areas are far beyond the values reported from other rivers and marine systems reported. This situation may be due to polluted discharging from some petrochemical industrial manufactories and worse traffic conditions in Tianjin.     

埋地管道腐蚀剩余寿命预测概率模型

为考察腐蚀参数的不确定性对埋地管道失效和剩余寿命的影响,建立以Shell—92确定性模型为基础的管道腐蚀剩余寿命预测概率模型。采用Monte-Carlo方法计算管道剩余寿命及其累积分布函数,并进行参数敏感性分析,详细研讨影响埋地管道腐蚀剩余寿命的主要参数及其随服役时间的变化规律。计算结果表明,提出的管道腐蚀剩余寿命预测模型能有效预测实际中受多因素影响的管道失效和剩余寿命问题。