道路交通事故发展趋势分析与预测

根据福建省2000 -2010年交通事故相关指标,采用统计图表分析法进行交通事故发展趋势分析与安全水平比较研究,结果表明交通事故各项绝对指标总体呈下降趋势,但从万车死亡率、受伤人数与死亡人数比及交通事故死亡人数占各类事故死亡人数比重等相对指标看,交通安全总体水平偏低,交通事故后果比较严重.对交通事故死亡人数与GDP、机动车保有量、公路通车里程、人口数四项影响因素进行了多元线性回归分析,分析得出四个影响因素总体对交通事故死亡人数的线性影响是显著的,采取向后筛选策略线性回归分析得出,死亡人数与GDP的线性关系是显著的,根据回归结果建立了交通事故的预测模型.     

Multiple categorization in resume screening: Examining effects on hiring discrimination against Arab applicants in field and lab settings

Debate exists as to what the more appropriate prediction is regarding the effects of multiple stigmatized group memberships on employment discrimination. The ethnic prominence (EP), multiple minority status (MMS), and subordinate male target hypotheses were assessed for the combined effects of ethnic group membership (Arabic), sex, social status, and job type on hiring evaluations. Two correspondence tests in the field (Study 1) and two experimental studies in the lab (Study 2) and in the field (Study 3) were conducted. Studies 1 and 2 showed evidence for the EP hypothesis when low‐status jobs were tested. The odds for rejection were four times higher for Arab than for Dutch applicants. Applicants' sex, socio‐economic status, and external client contact did not moderate findings (Study 1). The effect of applicants' ethnic group membership was further moderated by raters' motivation to control prejudice (Study 2). Study 3 showed evidence for the MMS hypothesis. We found double jeopardy against Arab women who applied for high‐status jobs when recruiters' prejudice was controlled. Study findings show that discrimination in resume screening may depend upon the particular intersection of applicant, job, and recruiter characteristics. We discussed implications for anonymous resume screening and research on evaluation of applicants possessing multiple stigmatizing characteristics. Copyright © 2011 John Wiley & Sons, Ltd.     

工业废水中氨氮测定预处理的新法探讨

针对带色浊度高的工业废水氨氮测定的预处理,提出了使用硫酸铝和聚丙烯酰胺(PAM)复合絮凝沉淀法。试验结果表明,方法不仅具有操作简单,试剂用量少,絮凝效果好,去色、去浊率高(达99.6％),且对pH5～10的各种带色浊度高的废水都能起到良好的效果,并能提高测定的精密度,其变异系数为1.2％～3.6％,回收率为90％～105％,确保了数据的准确和可靠。     

米诺效应中的多事故点协同作用后果研究

为了研究多米诺效应中多事故点协同作用的后果,将并联系统概率模型运用到贝叶斯概率计算过程中,体现出多事故点协同作用对多米 诺效应传播的概率影响;后果分析部分从人、物、环境3个方面出发,对事故的后果影响以及事故预防提出建议措施。最后运用模型对实例进行 了应用分析,结果表明:多事故点协同作用下储罐的多米诺失效概率增大,罐区危险性增强,可以通过对储罐设置安全屏障等措施,有效的切 断导致事故最大概率的链条。     

民航安全状况与社会经济指标关联分析

为了分析中国民航的安全趋势,基于中国民航1995-2014年安全生产历史数据和民航安全运行关系密切的26项社会经济指标,利用因子分析、相关系数等数学方法,建立了多元线性回归模型分析民航安全状况与社会经济指标的管理关联性。该模型表明对民航安全具有显著影响的社会经济指标包括国民经济、产业结构和人员素质。通过对比安全生产指标的拟合值和实际值,分析民航安全趋势的变化规律,并利用自回归移动平均模型预测2015-2018年民航安全生产指标值。计算结果显示该时间段内民航安全生产指标将处于历史高位,且呈现缓慢上升趋势。最后给出了针对行业安全监管、安全运行等方面的改进建议。     

城市多排污口对河流水质影响的模拟研究

通过实测阜新新邱长营子桥段5个连续排污口处污染物浓度,采用水平二维水质迁移模型对细河城市段排污口排出的生活废水及1 500 m长的细河河段进行模拟分析,计算出多排污口在耦合叠加作用下,河段内污染物的迁移扩散和污染物浓度的分布特征。模拟分析得出:第1、2、3年污染物在3个监测断面处的横向迁移距离和纵向迁移距离,污染物最大浓度所在的位置以及岸边处污染物浓度的分布规律曲线,为城市污水治理和城市规划提供一定的科学依据和指导。     

Structural equation-based latent growth curve modeling of watershed attribute-regulated stream sensitivity to reduced acidic deposition

Little information is available about the effects of watershed attributes on long-term stream chemical responses to reduced acidic deposition. Long-term chemical data (1980-2006) for 21 stream sites from the Appalachian Mountain region and data of 8 watershed attributes of the corresponding watersheds were analyzed to study such effects. Latent growth curve modeling (LGM), a structural equation modeling (SEM) approach, was conducted to quantify stream sensitivity to reduced acidic deposition in the region, and to model the initial chemical conditions (intercepts) and changing rates (slopes) in three time periods: 1980s, 1990s, and 2000s. The modeled chemical trends were generally consistent with those trends which were detected by trend analyses in a previous study. Watershed attributes including area, mean elevation, percentage of developed land, percentage of grassland, percentages of shale and sandstone, percentage of barren land, and percentage of soil type Gilpin-Upshur-Vandalia (GUV) were found to affect stream sensitivity to the reduced acidic deposition with their importance in the respective order. The stream sensitivity in turn regulated streams’ chemical initial conditions and their changing rates in the studied watersheds. This innovative application of LGM for modeling long-term chemical trends advanced our understanding of the role of watershed attributes in regulating streams’ responses to reduced acidic deposition. This approach can be applied for evaluating streams’ responses to acidic deposition in other regions and, more broadly, for studying causal effects on long-term behaviors in other ecological and environmental science subjects.     

A Comparison of Loch Chemistry from 1955 and 1999 in the Cairngorms,N.E. Scotland

The Cairngorms in north-east Scotland is remote from pollutant sources although it currently receives ca. 10 kg ha¹ yr¹ S and ca. 11 kg ha¹ yr¹ N deposition from the atmosphere.In 1955, 15 lochs (lakes) at a range of altitudes were sampled and analysed for major ion concentrations. A new survey of these and an additional 23 lochs and their catchment soils was conducted in 1999 to determine the impact of acid deposition, and the changes in loch chemistry since the 1955 survey. The bedrock geology of this region has a strong influence on the loch chemistry. Surface waters were generally more acidic in high altitude areas due to predominantly poorly buffered, thin alpine soils developed on granitic parent material (mean acid neutralising capacity (ANC) for 23 lochs = 30 eq L¹). At lower altitudes where the geology is dominated by Dalradian metamorphic rocks surface waters are comparatively base rich and have higher ANC (mean ANC for 15 lochs = 157 eq L¹). Surface water nitrate concentrations show a negative relationship with soil C:N status, in that higher nitrate only occurs at low soil C:N ratios. A comparison of data for 1955 and 1999 shows that sulphate concentrations are significantly lower (67.8 and 47.5 eq L¹, respectively), and pH has improved (pH 5.6 and 5.9) in response to decreased S deposition since the mid 1970s. However, mean nitrate concentrations were found to increase from 2.48 >eq L¹ in 1955 to 5.65 eq L¹ in 1999. Differences in the sampling and laboratory methods from 1955 and 1999 are acknowledged in the interpretation of data.     

Multiscale Methodological Framework to Derive Criteria and Indicators for Sustainability Evaluation of Peasant Natural Resource Management Systems

Design and implementation of more sustainable natural resource management systems is the current objective of many research institutions, development agencies, NGOs and other stakeholders. But, how to assess whether a system is sustainable? How do we know whether the alternatives designed will increase the sustainability of the system? How to evaluate or assess the sustainability of natural resource management systems?In this paper we present a multiscale methodological framework for sustainability evaluation. The framework is based on a systems approach from which five general attributes of sustainable natural resource management systems are defined based on scale- and discipline-independent properties (productivity, stability, resilience, reliability and adaptability).A general operational strategy to derive ‘site-specific’ criteria and indicators for the attributes at different scales is also presented. This strategy is based on the definition of ‘impact scales’, at which the different stakeholders can or want to design alternatives, as well as the main stakeholders’ objectives and constraints. The application of the multiscale framework is illustrated with a case study in the Purhepecha Region of Michoacán, a peasant mountainous region in the west of Mexico. We used stakeholder consultation to identify the main objectives and constraints as well as to select criteria and indicators. The sets of criteria and indicators suggested for the different scales of analysis of the Purhepecha Region are comprehensive, yet not exhaustive, and represent the main issues related to natural resource management in the region. Further work will be directed towards the quantification of indicators at different scales and their relationships and trade-offs.     

SIMULATION OF RUNOFF FROM URBAN WATERSHEDS1

ABSTRACT. .A mathematical model for urban watersheds is being developed in stages at the Utah Water Research Laboratory, Utah State University at Logan. In verifying the watershed as a unit, watershed coefficients are determined on the computer, and related to the urbanization characteristics. The second stage of verification consists of dividing the watershed into subzones, and determining the urban parameters within each subzone. Each subzone is then individually modeled, and outflow hydrographs are routed through succeeding downstream subzones to the gaging point. The model thus makes it possible to: (a) develop runoff models for subzone hydrographs within the urban watershed, and (b) account for spatial variations of storm and watershed characteristics. An attempt was also made to analytically model the outflow hydrograph based on storm and watershed characteristics.