基于均匀设计的事故再现模型参数敏感性分析

借助参数敏感性分析方法确定那些对事故再现结果有显著影响的参数,进而通过对这些参数进行合理处理则可在花费不大情况下确保再现结果的精度。基于均匀设计并结合回归分析,提出了一种事故再现模型参数敏感性分析方法:该方法首先借助均匀设计寻找到事故再现模型的一阶响应面模型,再借助该响应面模型获得原事故再现模型内参数的敏感性向量。并在此基础上进一步探讨了如何通过该方法获得各输入参数的取值区间及各输入参数在其标称值附近有一定程度扰动时2种情况下参数对计算结果的影响程度。最后给出一数值算例,算例结果表明:笔者方法所得参数敏感性顺序与其他学者研究所得一致。     

环评中不同性质项目工程分析内容的探讨

根据环境影响评价中工程分析篇章的目的及要求,探讨了新建、改扩建、技术改造三种不同建设性质项目的定义,分析了这三类项目工程分析篇章应编写的内容,并重点论述了其中的区别。     

太湖流域污水处理厂升级改造的措施与思考

太湖蓝藻事件的爆发促使了太湖流域污水处理厂大范围的升级改造,升级改造的主要措施有强化生物处理、深度处理等,具体工程措施需要结合水质处理要求、现有处理工艺、经济发展水平等进行比选。升级改造的出水水质需要结合纳污水体的污染现状和环境容量进行合理确定。升级改造过程中需要重视进水水质水量的设计与监控,加强工程投资和运行费用的控制。     

吉林省资源型城市可持续空间重构研究

以典型资源型城市吉林省辽源市为案例,探讨其城市空间结构的现状特征和空间问题;在理论框架分析与经验分析的基础上,从市区和市域两个尺度提出辽源市可持续城市空间结构的优化途径.     

工业事故演变混沌特性研究

混沌与随机是本质上不同的两种特性.区分产生工业事故演变系统的混沌性和随机性是进行工业事故模拟和预测的基础.本文通过对工业事故演变特性进行分析,初步结果表明,工业事故演变具有混沌动力系统的一些特征,提出通过相空间重构及Lyapunov指数来判定工业事故演变的混沌特性.     

The State of Protected Forest Communities in the European Forest–Steppe Zone of Russia and Prospects for Their Reconstruction: A Case Study of Specially Protected Areas of Penza Oblast

The structure of most forest communities in the European forest–steppe, including protected areas, has been disturbed. The adverse consequences of these disturbances include the incomplete age structure of the populations of cenosis-forming species and the irreversibility of successions. The conservation of biodiversity in the structurally disturbed communities is impossible without human intervention, which must be aimed at restoring their age heterogeneity with regard to their specific ecological features.     

LONG-TERM RECONSTRUCTION OF WATER LEVEL CHANGES FOR LAKE ATHABASCA BY ANALYSIS OF TREE RINGS1

ABSTRACT: The fact that dendrochronology can be a useful tool in water resources management is demonstrated by a study of past changes in lake levels. The study was necessitated by the recent (1967) closure of the gates on the W.A.C. Bennett Dam on the Peace River in British Columbia, causing a drop in water levels of Lake Athabasca, the lake levels control water level undulations in a series of smaller lakes which lie in the 1.5 million acre delta area along its western edge in Alberta. The W.A.C. Bennett Dam has by its regulation of the Peace River affected the river's historical role of creating a hydraulic dam during early summer flood stages thereby preventing outflow from Lake Athabasca and inducing annual inundation of the delta area. Because the ecololgy of the lake and adjacent delta region has depended on the now attenuated snow-melt flooding from the Upper Peace River Basin, it became necessary to consider some means of artificially inducing this annual inundation. It was not known, however, what the long-term water level changes were around which the present ecology had developed. Continuous historical lake level records exist only for the period 1935–1967. Was this period one of anomalously high or low water levels? Relatively old white spruce trees growing along natural levees of the channels in the delta region were found to contain tree-ring records that reflected the water stages in the channels. Because the water levels in the channels could be correlated with lake levels, it was possible to use the three-ring series to extend the known 33-year record of lake level changes to 158 years. By using canonical analysis and 10-day mean lake levels for three different subperiods in the 33-year period of calibration, along with tree-ring series from appropriately chosen stands of white spruce, reconstructions were made of the long-term record for late May, early July, and late September. The reconstructed record shows that the May 21–30 lake levels have been three times as variable in the past as in the period of historical record (1935–1967), the July 11–20 levels twice as variable, and the September 21–30 levels 10% less variable. However, the mean water level for each of the three subperiods for the long-term record is very close to the means for the period of historical record. The reconstructed record shows that, before the dam gates were closed, there was only one three-year period (1866–1868) in which the lake levels were as low as they have been since closure of the gates (that is, 1967–1970). (Levels were nearly as low, however, during the period 1942–1945.     

基于AHP的工业企业震后恢复重建优先等级评价

地震灾害一直是人类社会所面临的重大自然灾害之一,在灾害发生之后,为了能够让灾区较短时间内恢复正常的生产生活和社会运行,高效率的恢复重建机制不可或缺.在所有的震后恢复重建项目中,灾区原有的工业企业的恢复重建是一大重点,这些工业企业在灾前往往是当地政府税收的主要来源,也为当地人口提供了大量的就业岗位.然而,能够投入到灾区用...     

两种应用场景下NDVI时间序列数据拟合方法研究

植被覆盖指数（NDVI）时间序列数据集包含地表植被的长势、生长周期、时空变化等信息,其拟合重建结果可应用于物候信息提取、生态质量评价、人类活动扰动识别、覆被变化动态监测等方面。基于TIMESAT软件,选取物候参数提取和扰动识别2个应用场景,结合地面站点数据和Jacknife法模拟数据,对比分析非对称高斯函数拟合法（AG法）、双Logistic函数拟合法（D-L法）和Savitzky-Golay滤波法（S-G法）3种方法的拟合效果。结果表明：（1）3种方法拟合重建后提取的生长开始时间（SOS）、生长结束时间（EOS）、生长周期（LOS）等物候参数接近站点数据,AG法和D-L法保持NDVI时序曲线整体变化特征的能力较强,提取的SOS和EOS更接近站点数据;（2）人类活动扰动识别应用场景中,S-G法在滤波时能够最大限度地保留时序曲线细节变化,恢复速率相关系数达到0.618,回归估计标准差低于AG法和D-L法,因此识别精度最优。     

柠檬酸废水处理改造工程实例

采用多级内循环厌氧反应器MIC/上升式厌氧反应器UASB串联工艺处理柠檬酸生产排放的高浓度有机废水,其中厌氧处理段的COD去除率＞94％,整体COD去除率可达98.3％左右.最终排放口出水COD平均值为190 mg/L,pH值为6～9,达到柠檬酸行业废水排放标准.