离子选择电极分析法测定标样中氟化物的不确定度评定

通过对离子选择电极法测定标样中氟化物的过程研究，分析了该方法测量不确定度的来源，给出了相对不确定度分量，得出测量扩展不确定度的结果。     

Trends in summer sulphate in Europe

A trend analysis of the sulphate concentration in Europe in the summer half-year was performed. Data from various measuring networks were analysed, but only stations with quality assured sampling methods and a record of more than 10 years were included in the study. 1978 served as the reference year for the trend, because in that year most stations started operation. The relatively dense network in Belgium provided the most valuable data, as evidenced by the fact that two sites at a distance of only 10 km apart correlated better than 95% over a month. The two sites also show a correlation of better than 90% over a season with two other stations at distances of 45 and 95 km. The relative decrease in summer-sulphate at the four stations in Belgium, as analysed by linear regression, was 3.3% per year which corresponds to an absolute decrease of 0.42 μgm⁻³ per year. In the Netherlands the average yearly decrease in summer-sulphate at two stations was 3.5% (−0.34 μgm⁻³). In other countries stations were further apart or only a single site wits in use, which limits the representativeness of the data. In northwestern Germany, a region with several monitoring stations, a yearly averaged decrease of 3.0% occurred. The lower absolute decrease (0.25 μgm⁻³) per year compared to that in the two neighbouring countries reflects the lower summer-time sulphate concentrations. In the remainder of Germany the average decrease was 1.6%. In South-Scandinavia the yearly relative decrease at two sites was 2.6% (0.13 μgm⁻³ absolute). There was no significant trend in the U.K. Al the Polish station the levels increased, it decreased at the Hungarian and Austrian station and remained constant at the Czechoslovakian site. Reasons for omission of the data from France from the trend analysis are discussed.     

Sex pheromone components of male <Emphasis Type="Italic">Tirathaba mundella</Emphasis> (Lepidoptera: Pyralidae)

Summary. During peak calling activity by male oil palm bunch moths, Tirathaba mundella Walker (Lepidoptera: Pyralidae), their hairpencils, wings or entire body were extracted in hexane. Gas chromatographic-electroantennographic detection (GC-EAD) analyses of hair pencil extracts revealed four compounds that consistently elicited responses from female antennae. The NMR spectrum of isolated compound 1, and mass spectra and retention indices of compounds 1–4 suggested that they were (3S,6S)-2,2,6-trimethyl-6-vinyl-tetrahydro-pyran-3-ol (1), 4-hydroxy-3-methoxy-benzaldehyde (2, vanillin), 6,10,14-trimethyl-2-pentadecanone (3), and 6,10,14-trimethyl-2-pentadecanol (4). Comparative GC and GC-MS analyses of hair pencils extract and synthetic standards confirmed these structural assignments. Moreover, comparative chromatography of synthetic and hairpencil-isolated 1 on a Cyclodex-B column (which separated the four stereoisomers with baseline resolution) revealed that male T. mundella produce the SS-stereoisomer (SS-1). In field cage bioassay experiments in Palembang, Indonesia, synthetic SS-1 and vanillin in combination, but not singly, attracted female T. mundella. SS-1 plus vanillin were as effective as male T. mundella in attracting females. Compounds 3 and 4 did not enhance the blend's attractiveness. Received October 11 2002; accepted March 14, 2003. R1D=" Correspondence to: Gerhard Gries, email: gries@sfu.ca     

Bayesian testing for trend in a power model for clustered binary data

Developmental toxicity studies are widely used to investigate the potential risk of environmental hazards. In dose–response experiments, subjects are randomly allocated to groups receiving various dose levels. Tests for trend are then often applied to assess possible dose effects. Recent techniques for risk assessment in this area are based on fitting dose–response models. The complexity of such studies implies a number of non-trivial challenges for model development and the construction of dose-related trend tests, including the hierarchical structure of the data, litter effects inducing extra variation, the functional form of the dose–response curve, the adverse event at dam or at fetus level, the inference paradigm, etc. The purpose of this paper is to propose a Bayesian trend test based on a non-linear power model for the dose effect and using an appropriate model for clustered binary data. Our work is motivated by the analysis of developmental toxicity studies, in which the offspring of exposed and control rodents are examined for defects. Simulations show the performance of the method over a number of samples generated under typical experimental conditions.     

Some statistical and conceptual issues in the detection of low-level environmental pollutants

With increasing concern over chemicals that are potential health hazards at low levels, determination of limits of detection have undergone considerable scrutiny. Most traditional detection limit estimators suffer from extensive statistical and/or conceptual limitations. In this paper, traditional detection limit estimators are described and critically evaluated. Using the terminology of Currie (1968), methods are categorized into decision limits versus detection limits. The methods are further categorized into single concentration design versus calibration design methodologies. While the single concentration design methods are useful for fixing ideas and clarifying definitions, they are shown to be extremely limited in practice since dependence of variability on concentration can neither be estimated or incorporated. Calibration-based detection limit estimators are described, compared and contrasted. Generalizations to non-constant variance, multiple future detection decisions and simultaneous control of Type I and II errors are provided. The various calibration-based methods are illustrated using real data and experimental design issues for detection limit studies discussed.     

Detection and delineation of critical areas using echelons and spatial scan statistics with synoptic cellular data

Geographical surveillance for hotspot detection and delineation has become an important area of investigation both in geospatial ecosystem health and in geospatial public health. In order to find critical areas based on synoptic cellular data, geospatial ecosystem health investigations apply recently discovered echelon tools. In order to find elevated rate areas based on synoptic cellular data, geospatial public health investigations apply recently discovered spatial scan statistic tools. The purpose of this paper is to conceptualize a joint role for these together in the spirit of a cross-disciplinary cross-fertilization to accomplish more effective and efficient geographical surveillance for hotspot detection and delineation, and early warning system.     

当前环境激素的研究状况

着重介绍了环境激素的种类、作用机制、对生物的及人体健康的潜在危害、筛选环境激素类物质的方法及今后的研究展望。     

硫化氢气体快速检测方法研究

研究了快速监测硫化氢气体的新方法——硫化氢被动式检气管方法。该法是基于气体分子扩散(Fick)定律和化学吸收原理,将检气管内的海棉载体涂渍上对硫化氢有特效的显色剂(缓冲液G和醋酸铅)。测定时,硫化氢通过检气管端口扩散进入管内,在经过载体时,与载体上的显色剂发生反应,从而产生明显的颜色变化(浅黄色变成棕黑色)。检气管显色长度的平方与硫化氢质量浓度及采样时间的乘积在50~1500mg·m-3范围内成线性关系,从而快速监测环境中硫化氢的时间加权平均质量浓度。该检气管集采样与分析为一体,可快速测定硫化氢气体的质量浓度。与传统的采样分析方法比较,该检气管结构简单,操作方便,不受被测环境的空间大小、有无电源等影响;携带方便,利于外出测定和大面积布点测定。经过应用实验表明,该检气管具有较高的灵敏度,达到设计要求。     

改革开放以来我国国土整治历程回顾与新构想

改革开放40多年,国土整治随着资源、生态环境领域政治意愿和体制的变迁而变化,经历兴起、搁浅、整合的过程。在梳理改革开放40余年国土整治领域重要政策文件基础上,总结了国土整治历程中的发展经验、主要问题以及新趋势,并提出了新时代国土整治新构想。新时代国土整治目标将牢牢结合生态文明战略,以期实现空间、资源、生态环境优化,打造以人为本高品质国土空间。新时代国土整治是通过“承载力”“适宜性”评价机制,结合综合研判、归因分析划分“国土整治”功能分区开展重大工程,多措并举处置国土开发利用过程中“负外部性”问题,修复国土功能,以实现空间结构优化调整、资源高效利用、生态保护修复、灾害污染治理,以期提升国土空间承载力、适宜性、美丽度、安全性,提升国土可持续发展能力的综合治理活动。