饮用水中总α、β放射性的测量

本文利用CLB-104型低本底,对饮用水中的总α、β放射性进行测量。介绍了仪器试剂及样品的预处理,上机测量等方法。并对黑龙江省某城市的饮用水进行取样监测,得出该城市饮用水总α浓度为:0.0208-0.0233Bq/L;总β浓度为:0.0805-0.0962Bq/L。     

环境自动监测系统维护方法论初探

将环境监测系统维护的方法理论化,对自动监测系统维护和监测仪器进行理论定义.在自动监测系统维护的过程中,从硬件和软件两个方面,用排除、逆向思维、类比、变通以及拓展的方法对仪器故障问题进行科学的分析处理.     

智能时代机械自动化安全技术应用发展趋势探析——评《机械安全技术及应用》

在人类发展历程中,机械应用使人类极大提高了生产效率,也赋予了人类改造自然的强大力量。尤其是近现代科技革命以来,机械对社会迅速发展的促进作用巨大,在当今世界机械已经应用到生产的各个领域。自从机械技术大规模应用以来,机械安全技术也随之产生,毕竟机械具有强大的力量,一旦出现安全问题,就可能会带来难以预测的伤害。机械安全技术发展与机械应用推广是相互促进的,机械安全技术发展推动了机械应用推广,而机械应用推广又提高了机械安全技术要求。尤其是随着近现代人本主义管理理念兴起,工业生产中应用机械技术更注重人的安全与健康要求,进一步促进了机械安全技术的发展与进步。随着科学技术的迅猛发展,尤其是自动控制技术与智能化技术时代到来,机械自动化发展趋势不可阻挡。     

流量高度变化的河流溶解氧模型的开发与应用

在一系列实验室与现场测量和监测数据的基础上,研究人员开发建立了拉维河溶解氧(DO)的模型框架.无论是经典的斯特里特-菲尔普斯(CSP)模型,还是修正后的斯特里特-菲尔普斯(MSP)模型,均用于溶解氧的模拟.在修正后     

Application of the AERMOD modeling system for environmental impact assessment of NO2 emissions from a cement complex

We applied the model of American Meteorological Society-Environmental Protection Agency Regulatory Model (AERMOD) as a tool for the analysis of nitrogen dioxide (NO2) emissions from a cement complex as a part of the environmental impact assessment. The dispersion of NO2 from four cement plants within the selected cement complex were investigated both by measurement and AERMOD simulation in dry and wet seasons. Simulated values of NO2 emissions were compared with those obtained during a 7-day continuous measurement campaign at 12 receptors. It was predicted that NO2 concentration peaks were found more within 1 to 5 km, where the measurement and simulation were in good agreement, than at the receptors 5 km further away from the reference point. The Quantile- Quantile plots of NO2 concentrations in dry season were mostly fitted to the middle line compared to those in wet season. This can be attributed to high NO2 wet deposition. The results show that for both the measurement and the simulation using the AERMOD, NO2 concentrations do not exceed the NO2 concentration limit set by the National Ambient Air Quality Standards (NAAQS) of Thailand. This indicates that NO2 emissions from the cement complex have no significant impact on nearby communities. It can be concluded that the AERMOD can provide useful information to identify high pollution impact areas for the EIA guidelines.     

In vitro fluorescence displacement investigation of thyroxine transport disruption by bisphenol A

Bisphenol A (BPA) is a chemical with high production volume and wide applications in many industries. Although BPA is known as an endocrine disruptor, its toxic mechanisms have not been fully characterized. Due to its structural similarity to thyroid hormones thyroxine (T4) and triiodothyronine (T3), one possible mechanism of BPA toxicity is disruption of hormone transport by competitive binding with the transport proteins. In this study, the binding interactions of BPA, T4, and T3 with three thyroid hormone transport proteins, human serum albumin (HSA), transthyretin (TTR), and thyroxine-binding globulin (TBG) were investigated by fluorescence measurement. Using two site-specific fluorescence probes dansylamide and dansyl-L-proline, the binding constants of BPA with HSA at drug site I and site II were determined as 2.90 104 and 3.14 104 L/mol, respectively. By monitoring the intrinsic fluorescence of tryptophan, a binding constant of 4.70 103 L/mol was obtained. Similarly, by employing 8-anilino-1-naphthalenesulfonic acid as fluorescence probe, the binding a nity of BPA with TTR and TBG was measured to be 3.10 105 and 5.90 105 L/mol, respectively. In general, BPA showed lower binding a nity with the proteins than T3 did, and even lower a nity than T4. Using these binding constants, the amount of BPA which would bind to the transport proteins in human plasma was estimated. These results suggest that the concentrations of BPA commonly found in human plasma are probably not high enough to interfere with T4 transport.     

Estimation and comparison of night-time OH levels in the UK urban atmosphere using two di erent analysis methods

Night-time OH levels have been determined for UK urban surface environments using two methods, the decay and steady state approximation methods. Measurement data from the UK National Environmental Technology Centre archive for four urban sites (Bristol, Harwell, London Eltham and Edinburgh) over the time period of 1996 to 2000 have been used in this study. Three reactive alkenes, namely isoprene, 1,3-butadiene and trans-2-pentene were chosen for the calculation of OH levels by the decay method. Hourly measurements of NO, NO2, O3, CO and 20 VOCs were used to determine night-time OH level using the steady state approximation method. Our results showed that the night-time OH levels were in the range of 1 105–1 106 molecules/cm3 at these four urban sites in the UK. The application of a t-test of these analyses indicated that except Bristol, there was no significant di erence between the OH levels found from the decay and steady state approximation methods. Night-time levels of the OH radical appeared to peak in summer and spring time tracking the night-time O3 levels which also passed through a maximum at this time.     

Atmospheric mercury over the marine boundary layer observed during the third China Arctic Research Expedition

TGM measurements on board ships have proved to provide valuable complementary information to measurements by a ground based monitoring network. During the third China Arctic Research Expedition (from July 11 to September 24, 2008), TGM concentrations over the marine boundary layer along the cruise path were in-situ measured using an automatic mercury vapor analyzer. Here we firstly reported the results in Japan Sea, North Western Pacific Ocean and Bering Sea, where there are rare reports. The value ranged between 0.30 and 6.02 ng/m³ with an average of (1.52 ± 0.68) ng/m³, being slightly lower than the background value of Northern Hemisphere (1.7 ng/m³). Notably TGM showed considerably spatial and temporal variation. Geographically, the average value of TGM in Bering Sea was higher than those observed in Japan Sea and North Western Pacific Ocean. In the north of Japan Sea TGM levels were found to be lower than 0.5 ng/m³ during forward cruise and displayed obviously diurnal cycle, indicating potential oxidation of gaseous mercury in the atmosphere. The pronounced episode was recorded as well. Enhanced levels of TGM were observed in the coastal regions of southern Japan Sea during backward cruise due primarily to air masses transported from the adjacent mainland reflecting the contribution from anthropogenic sources. When ship returned back and passed through Kamchatka Peninsula TGM increased by the potential contamination from volcano emissions.     

自动增氧人工湿地处理农村生活污水脱氮研究

针对人工湿地中溶解氧浓度不足和脱氮率偏低的问题,设计了自动增氧人工湿地进行农村生活污水处理对比试验研究.结果表明,自动增氧湿地内的DO浓度比普通人工湿地高0.3me期mg/L左右,TN、NH<,4><'+>-N去除率分别达到了67.41%、69.114%,比普通湿地高14.57%、19.79%.同时,自动增氧人工湿地系统中的亚硝化细菌、硝化细菌数量均高于普通人工湿地系统,说明自动增氧措施对于提高人工湿地脱氮效率是有效的.     

森林公园景观水系自动监测水质预警体系研究

以奥运森林公园南区景观水系为背景,探讨了如何建立基于自动监测的水质预警体系.水质预警体系中包含5个部分:风险因素自动识别、风险因素定量化分析和预测、水质预测、水质警报指标体系与水质预警、对策及防范措施.结合奥运森林公园南区景观水系的具体情况,分析了上述水质预警体系中各部分的主要实现方法,给出了动态率定法、统计模型法、机...