基于LIMS数据库的环境监测数据统计方法——以上海市嘉定区实验室信息系统为例

实验室信息管理系统(Laboratory Information Management System,LIMS)在环境监测领域中,已经逐渐地得到了普及,在LIMS数据库中涵盖了大量的环境监测信息和数据,与传统的数据统计方法相比,通过SQL语句对LIMS数据库进行SELECT操作,能够大大提高统计的效率和准确性。     

火灾探测的原理和方法(下)

简述了火灾现象的物理特征、火灾探测的基本原理并对火灾探测算法的建立及发展作了介绍。对产生火灾误报警的原因进行了分析，指出要改善火灾探测的准确性，缺少的不是思路和技术，而是火灾科学基础研究的积累。     

1994／1995全球重大自然灾害的统计分析

１９９４／１９９５年是６０年代以来全球自然灾害经济损失最大的两年。作者根据收集到的信息，对全球这两年的重大自然灾害的分布及灾情作了统计。结果表明，９０年代全球重大自然灾害的经济和保险损失存在上升趋势。最后，对其成因进行了分析     

REGIONAL WATER QUALITY MANAGEMENT BY THE GENERALIZED REDUCED GRADIENT METHOD1

ABSTRACT: A river basin-wide water quality management system is considered. The river receives thermal as well as organic wastes. At-source treatment of these pollutants is imposed to control the basin-wide water quality. The related water quality standards are: the minimum DO concentration, the maximum allowable BOD concentration, the maximum allowable stream temperature, and the allowable rise in stream temperature. The general dynamic mathematical model representing water quality in streams and the thermal effects on BOD and DO concentrations is presented. The model is highly nonlinear in nature. The optimal management problem involving the model is solved by a recently developed nonlinear propgramming technique - the generalized reduced gradient (GRG) method. Comparison of results obtained by the GRG method vs. dynamic programming, and of results using a more realistic mathematical model vs. a simple model are presented. The analysis procedure can be applied to designing new and examining existing water quality programs, and to study the influence of alternate policies and constraints.     

What do significance tests really tell us about the environment?

Routine application of significance tests does not extract the maximum information from environmental data and can lead to misleading conclusions. Reasons leading to this are: a significant result can often be reached merely by collecting enough samples; a statistically significant result is not necessarily practically significant; and reports of the presence or absence of statistically significant differences for multiple tests are not comparable unless identical sample sizes are used. These problems are demonstrated by application to pH data for grazed and retired fields, and by discussion of significance tests used in recent US regulations for groundwater quality. The advantages of equivalence tests, where the tester must state the difference of practical difference, are discussed and applied to the field pH problem. We recommend that environmental managers and scientists pay more attention to statistical power and decide on what is a practical difference. Confidence intervals for the size of the differences, accompanied where necessary by equivalence tests, are the preferred means of addressing the question: “is there a difference of practical significance?”     

A HYBRID OPTIMIZATION APPROACH TO THE ESTIMATION OF DISTRIBUTED PARAMETERS IN TWO-DIMENSIONAL CONFINED AQUIFERS1

ABSTRACT: In using non-linear optimization techniques for estimation of parameters in a distributed ground water model, the initial values of the parameters and prior information about them play important roles. In this paper, the genetic algorithm (GA) is combined with the truncated-Newton search technique to estimate groundwater parameters for a confined steady-state ground water model. Use of prior information about the parameters is shown to be important in estimating correct or near-correct values of parameters on a regional scale. The amount of prior information needed for an accurate solution is estimated by evaluation of the sensitivity of the performance function to the parameters. For the example presented here, it is experimentally demonstrated that only one piece of prior information of the least sensitive parameter is sufficient to arrive at the global or near-global optimum solution. For hydraulic head data with measurement errors, the error in the estimation of parameters increases as the standard deviation of the errors increases. Results from our experiments show that, in general, the accuracy of the estimated parameters depends on the level of noise in the hydraulic head data and the initial values used in the truncated-Newton search technique.     

中国近五百年流域性洪涝统计特征研究

本文以《中国近五百年旱涝分布图集》为基础，并将资料适当延长，提出了流域性洪涝及其指标。在此基础上，初步分析了我国主要流域单元近５００年（１４７０￣１９９１年）和各世纪流域性洪涝事件发生折频次和持续性，并分析了南方、北方和全区域主要流域单元不同等级流域性洪涝空间遭遇的可能性。     

校准曲线的系统处理方法

对校准曲线通过标准化余差法进行点位离群检验，通过相关系数相关性检验，对截矩进行检验，根据检验结果确定出基本上消除系统误差，随机误差较小的回归方程。     

维多利亚蓝B与碘在水溶液中的显色反应-吸光光度法测定海产品中的碘

研究了水相中,维多利亚蓝B与碘离子(I~-)的显色反应.当磷酸浓度为1.6mol/L,聚乙烯醇为0.08％时,维多利亚蓝B与碘形成络合比为1∶3的络合物,最大吸收峰位于375nm处,表观摩尔吸光系数为1.02×10~4L/mol·cm,碘在(0～16)μg/ml范围内符合比耳定律.方法可用于海洋生物等样品中的微量碘测定,结果满意.     

油类物质测定的几个影响因素及改进

通过用重量法测定水中油类物质的几个影响因素的研究，得出了能够取得满意测定结果的方法．改进后的方法，减轻了工作量，节省了分析费用，有利于批量分析．