A Contribution to the Study of the Antidust Respirators’ Real Performance

In most industrial enterprises, hazardous factors are present in quantities exceeding permissible levels. Such a situation requires using antidust respiratory protection. It has been suggested, however, that filters for respirators are not assessed properly and that lab results might not be related to real filtering efficiency in industry. This article contains test results of some commercially available filtering half-masks, including the effect of loading with real dust, high humidity, high temperature, and a combination of loading with dust and high humidity on the half-masks’ performance. The results show that the effect of these factors is considerable and that a combination of loading with silica dust and exposing to high humidity can cause a complete loss of performance.     

国家标准GB/T23469-2009《坠落防护 连接器》解读

国家标准GB/T 24569-2009《坠落防护连接器》规定了连接器的一般要求、技术性能、测试方法及标识。本文从标准适用范围、连接器分类、一般要求、技术性能等方面对该标准进行了解读,并结合我国连接器近些年的发展现状简述了标准对行业的推动作用,以加深相关方对该标准的理解和重视,促进其在连接器生产及检测方面的指导作用。     

I can't get no job satisfaction: Meta‐analysis comparing permanent and contingent workers

Scholars are concerned that contingent workers experience more adverse psychological job outcomes than permanent employees, but the empirical work on job satisfaction is mixed. The purpose of this study was to quantitatively summarize the potential mean differences in job satisfaction between contingent workers and permanent employees. Meta‐analytic results from 72 primary studies (N = 237 856) suggest that compared with permanent employees, contingent workers experience lower job satisfaction (d = ?0.21); but when outlying primary studies are removed, the mean difference is small but significant (d = ?0.06). Methodological artifacts explain small but significant differences in job satisfaction but do not account for much variance. Moderator analyses support previous findings that contingent workers are not a homogeneous group; some contingent workers (e.g., agency workers) experience lower job satisfaction than permanent employees, whereas the job satisfaction of other contingent workers (e.g., contractors) is similar to permanent employees. The findings have implications for increasing our understanding of job satisfaction by showing that job satisfaction appears to vary by employment type. Practical implications suggest that extending human resource practices to contingent workers may increase their job satisfaction, which has been shown to influence job performance, citizenship behaviors, and turnover. Copyright © 2012 John Wiley & Sons, Ltd.     

我国《土壤环境质量标准》中重金属污染相关问题探讨

我国《土壤环境质量标准》（GB 15168—1995）的颁布促进了土壤资源的保护、管理与监督,但由于时间跨度过长社会发展较快,已经不能满足目前实际应用的需要。本文概述了发达国家关于土壤重金属污染的相关指导值/筛选值,并总结了我国现行土壤环境质量标准实施以来存在的问题及近年来的研究进展,对我国《土壤环境质量标准》的修订进行了探讨。     

综合评分法筛选水污染物排放控制因子

控制因子筛选是工业水污染物排放标准制定的重要环节。控制因子筛选应从工业原材料主要成分、排放污染物种类分析着手,逐步缩小备选名单范围。对进入初始名单的污染物,通过综合评分法评价其毒性和暴露水平两方面因素,选择潜在危害指数、年排放量和环境检出率三个指标,制定评分标准,根据各污染物得分情况确定其在排放标准中加以控制的必要性,并以此为主要参考依据确定控制因子。     

协定水污染物间接排放标准的法律问题探究

以协商的方式确定水污染物间接排放标准的规定打破了人们对标准确定性、强制性的传统认识。协定标准的优势在于充分利用污水处理厂的污水处理能力,减轻企业的污水处理负担,使企业可以集中力量搞生产。协定标准具有灵活性和优越性,应充分利用。通过对协定标准概念和重要性的分析,指出协定标准存在效力不确定、缺少对协定范围的限制等问题,造成协定标准在实践中通常被忽视或者滥用。并从明确协定标准的范围、加强排污企业的管理和协定标准的监督等方面,进一步提出了限制和完善水污染物间接排放标准的建议。     

基准氧含量在大气固定源污染物排放标准中的应用与启示

基准氧含量是大气固定源污染物排放标准中的一项重要指标,直接影响着对污染物排放浓度的达标判断。收集整理了近年来国家和地方制修订的主要大气固定源污染物排放标准,深入分析了基准氧含量指标在标准中的优化调整情况、实际应用效果及制修订背景和作用。针对基准氧含量在标准应用中仍存在着行业符合性划分不细致、适用条件不明确等问题,提出了以生产工艺和生产设施为基础,科学合理规定基准氧含量的建议。     

地面风场风速测量标准装置需求与设计

针对地面风场中风速测量仪器计量测试的需求,提出了风速测量标准装置的组成及性能指标设计要求,详细分析了风速测量标准装置各个重要部件的设计关键技术,结果表明该设计科学合理。     

基于K-means聚类分析法的肇庆市干季PM2.5污染天气分型研究

通过分析肇庆市2013—2018年国控大气环境监测站的PM_(2.5)连续监测数据,发现肇庆市区PM_(2.5)浓度在干季(10月—次年4月)明显高于其余月份,轻度以上污染基本发生在干季,且PM_(2.5)浓度对年总浓度贡献达70.8%.基于Era-interim再分析资料采用K-means聚类分析法对2013—2018年干季逐日的海平面气压和10 m水平风进行分型,揭示了肇庆市易出现PM_(2.5)污染的6种大气环流形势,包括冷锋前部(CF)、变性高压脊(THR)、脊后槽前型(BRFT)、高压底后部(HSW)、弱冷高压脊(HR)和台风外围型(TP).2013—2016年易污染天气型影响天数呈明显减少趋势,2017—2018年呈增加趋势.不同天气型PM_(2.5)浓度与局地气象要素相关性不一致,其中CF、HR、HSW、TP天气型与湿度相关性最好,THR与风速、BRFT与气压相关性最好.PM_(2.5)污染除BRFT天气型主要以本地排放累积影响为主,其余易污染天气型存在不同尺度的外来输送影响,HSW、HR主要来自广州、清远、韶关, CF主要来自佛山、中山,THR来自广州、清远、佛山.同一污染天气型在不同月份的污染影响差异较大,其中HSW、THR污染型主要影响1月和10月,CF为1月和12月,HR为2月和12月,TP为10月,BRFT为1月和10—11月.不同年份的同一月份造成不同程度的PM_(2.5)污染除了排放影响,还与天气环流类型和同一天气型下的局地气象要素密切相关.     

Development of an Ecologic Marine Classification in the New Zealand Region

We describe here the development of an ecosystem classification designed to underpin the conservation management of marine environments in the New Zealand region. The classification was defined using multivariate classification using explicit environmental layers chosen for their role in driving spatial variation in biologic patterns: depth, mean annual solar radiation, winter sea surface temperature, annual amplitude of sea surface temperature, spatial gradient of sea surface temperature, summer sea surface temperature anomaly, mean wave-induced orbital velocity at the seabed, tidal current velocity, and seabed slope. All variables were derived as gridded data layers at a resolution of 1 km. Variables were selected by assessing their degree of correlation with biologic distributions using separate data sets for demersal fish, benthic invertebrates, and chlorophyll-a. We developed a tuning procedure based on the Mantel test to refine the classification's discrimination of variation in biologic character. This was achieved by increasing the weighting of variables that play a dominant role and/or by transforming variables where this increased their correlation with biologic differences. We assessed the classification's ability to discriminate biologic variation using analysis of similarity. This indicated that the discrimination of biologic differences generally increased with increasing classification detail and varied for different taxonomic groups. Advantages of using a numeric approach compared with geographic-based (regionalisation) approaches include better representation of spatial patterns of variation and the ability to apply the classification at widely varying levels of detail. We expect this classification to provide a useful framework for a range of management applications, including providing frameworks for environmental monitoring and reporting and identifying representative areas for conservation.