PESTICIDES IN GROUND WATER: DO ATRAZINE METABOLITES MATTER?1

ABSTRACT: Atrazine and atrazine-residue (atrazine + two metabolites - deethylatrazine and deisopropylatrazine) concentrations were examined to determine if consideration of these atrazine metabolites substantially adds to our understanding of the distribution of this pesticide in groundwater of the midcontinental United States. The mean of atrazine.residue concentrations was 53 percent greater than that of atrazine alone for those observations above the detection limit (> 0.05 μg/l). Furthermore, a censored regression analysis using atrazine-residue concentrations revealed significant factors not identified when only atrazine concentrations were used. Thus, knowledge of concentrations of these atrazine metabolites is required to obtain a true estimation of risk of using these aquifers as sources for drinking water, and such knowledge also provides information that ultimately may be important for future management policies designed to reduce atrazine concentrations in ground water.     

宁波台地倾斜在皎口地震活动中的前兆反应特征

通过对宁波台地倾斜近几年来观测资料的分析，发现其在皎口几组地震事件前有不同程度的异常反应。在分量图上，震前出现了短临期前兆异常反应特征，并且有异常时间越长，幅度越大，地震震级就越高的特点。此外还对异常出现的成因作了探讨     

土氡测量在地质灾害勘测中的干扰实验研究

对土氡勘测中来自测量过程、勘测场地条件、气象因素方面的常见干扰进行了实验研究，探讨了干扰机理，指出了定性及部分定量排除干扰的方法。     

地貌对矿区环境,灾害的影响与对策

论述了地貌对矿区环境、灾害的产生及发展的影响，并以中国几个矿区的实例论述这一问题，同时，提出一些减缓影响的对策．     

重力式码头的震害预测

本文根据重力式码头的结构地震荷载计算和地震破坏的经验，建立了重力式码头的震害预测方法。并用此方法对烟台港的重力式码头进行了震害预测。     

建筑火灾区域模拟竖孔流动的计算

本文根据建筑火灾双层区域模拟思想，给出其常微分控制方程组，并分析了其压力求解方法，然后，运用伯努力利方程推导了相邻房间通过矩形竖孔（门或窗）的质量流率计算公式，还讨论了竖孔流动中性面产生条件。在此基础上，结合一两房间、两孔建筑中烟气运动实例，运用Ｃ．Ｗ．Ｇｅａｒ刚性稳定算法对火灾发展及烟气流动过程进行了数值模拟；给出各竖孔中性面位置、数量和各主环境之间通过竖孔的质量流率；还给出各房间气体平均温升、     

Accidents and risk control

A framework for transformation of knowledge and experience from risk analysis to emergency education is presented. An accident model was developed built on the concept “uncontrolled flow of energy (UFOE)”, where essential elements are the state, location and movement of the energy. A UFOE can be considered as the driving force of an accident, e.g. an explosion, a release of heavy gases. A domain model has been developed for representing emergencies occurring in society. A domain is a group of activities with allied goals and elements, and the domain model uses three main categories: status, context and objectives. Ten specific domains have been investigated including process plant, energy production and distribution, natural disasters and different sorts of transport. Totally 25 accident cases were consulted and information was extracted for filling into the schematic representations with two to four cases pr. specific domain.     

高层建筑楼梯间正压送风方式的浅析

本文对建筑防火设计中正压我系统的系统设计和送风方式进行了详尽的阐述。文章中列举了封闭楼梯间和防烟楼梯间的送风量计算方法，并针对目前两种主要送风方式，即点送风与竖井送风方式的特点，从理论上分析点风方式的应用前景。作者们还对北京西苑饭店主楼和北京新世纪饭店主楼等高层和超高层的大型建筑进行两种不同方式的楼梯间正压送风试验，进行了点式送风方式和竖井送风方式的对比试验，精确地测量了点式送风方式下的楼梯间正奔     

热混合层中温度脉动的分形特性

运用计盒维数方法对测量热混合层所得到的温度脉动时间系列信号进行了详细研究，对等温界面（ｉｓｏｔｈｅｒｍｉｎｔｅｒｆａｃｅ）截取时间点集合的分形维数Ｄ＝ｌｏｇ（Ｎ（ｒ））／ｌｏｇｒ在一定的尺度范围内进行了估算，界面阀值温度范围为Ｔ±１．５Ｔ′（Ｔ，Ｔ′为测量点的平均温度和脉动温度），发现对同一热混合层垂直面的不同测量点存在相同的Ｄ＝０．３５±０．０８     

喷射溶气回流浮选工艺处理含油废水

采用喷射溶气回流浮选工艺处理含油废水，替代原来的全加压溶气浮选工艺，提高了浮选过程的处理效果，增强了系统的抗负荷冲击能力，浮选出水油含量由原来的〈４０ｍｇ／Ｌ降至〈２０ｍｇ／Ｌ，ＣＯＤ由原来的〈１５０ｍｇ／Ｌ降至〈１１０ｍｇ／Ｌ。