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61.
简述了我国环境标准的现状,体系和分类,分析了环境标准在环境管理中的作用。指出环境标准是制定环境规划的重要依据;是各级环保部门行使管理职能的基本依据;是企业污染治理是否达标的限定值;是推动环保科技进步的动力;是环境评价的准绳;是开展环境保护工作的基础;是环境保护法规的重要组成部分;具有投资导向作用。 相似文献
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通过阿尔山市2005年大气中总悬浮微粒(TSP)的全年三个监测点的监测结果,结合采样时有关气象参数,着重对TSP与气象条件的关系做一下分析、研讨。 相似文献
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INTRODUCTION: The purpose of this study was to determine factors associated with seat belt usage among Emergency Medical Technicians (EMTs). METHODS: As part of biennial re-registration paperwork, nationally registered EMTs completed a survey on the safety and health risks facing Emergency Medical Services (EMS) providers. Respondents were asked to describe their seat belt use while in the front seats of an ambulance. They were categorized as "high" in seat belt use if it had been more than a year since they had not worn their seat belt or "low" in seat belt use if they had not worn their seat belt at least once within the past 12 months. A logistic regression model was fit to estimate the association between seat belt use, organizational seat belt policy, type of EMS organization worked for, EMT certification level, and the size of community where EMS work is performed. RESULTS: Of the 41,823 EMTs that re-registered in 2003, surveys were received from 29,575 (70.7%). A significant interaction between organizational seat belt policy and type of EMS organization was found to exist. Participants reporting no organizational seat belt policy had lower odds of seat belt usage when compared to individuals that do have a seat belt policy. Odds Ratios ranged from 0.20 (95% CI 0.10-0.40) for military organizations to 0.59 (95% CI 0.38-0.93) for private EMS organizations. Paramedics and those working in rural areas also had lower odds of seat belt use. CONCLUSION: Several factors were found to be associated with seat belt usage among EMTs while in the front compartment of an ambulance. However, it appears that only one, organizational policy, is a modifiable characteristic. 相似文献
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Arturo Ruiz-Luna Rafael Bautista Bautista Rafael Hernández-Guzmán Vera Camacho-Valdez 《Local Environment》2013,18(5):458-472
ABSTRACTExtent and distribution of urban green spaces (UGS) in Mazatlan (Mexico) are analysed using remote sensing and GIS techniques. Vegetated areas (2,270?ha), a third of the urban area in 2015, were reclassified into green spaces (GS), urban tree (UT) and open spaces (OS), based in the normalised difference vegetation index, relating them with demographic and socioeconomic data. UGS allocation per capita amount 55?m2, mainly represented by the UT class, with the largest patches associated with low developed and very high marginalised areas, and also with very low marginalised sectors, while the lowest allocation correspond to medium and low marginalisation, highly populated sector, without significant correlations. Despite the USG allocation, it is required a better urban planning to maintain public UGS and to protect the local flora, threatened by the introduction of exotic, ornamental species (64% of UT), to guarantee the provision of ecosystem services to the population. 相似文献
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宁波南沙港网箱养殖水域营养状况评价及生物修复策略 总被引:1,自引:0,他引:1
根据2007年1月-2007年11月4个航次对宁波南沙港网箱养殖水域水体营养盐(NO2--N、NO3--N、NH 4+-N和PO34--P)含量的监测结果,利用营养指数E法对水体的富营养化状态进行了评价。根据网箱养殖系统物质平衡方程和现场调查实验数据,估算了南沙港网箱养殖水域的氮磷污染负荷,以溶解态氮作为平衡指标,估算了鱼藻类合理的配比模式。结果表明,南沙港水体中NO2--N、NO3--N、NH4+-N、PO4-P含量年变化范围分别为0.26μmol/L~4.86μmol/L,33.93μmol/L~82.86μmol/L,0.59μmol/L~7.86μmol/L,1.47μmol/L~2.97μmol/L,不同养殖区之间营养盐含量差异不显著(p〈0.05);营养指数E值年变化范围介于2.41~15.99之间,表明该港水体处于重度富营养化状态;养殖区N/P值的年平均值为32.95,表明南沙港海区是一个氮过剩的养殖系统。南沙港网箱养殖水域氮、磷的负荷量分别为70.43 t/a和5.96 t/a,其中溶解态氮、磷负荷量分别为49.3 t/a和2.38 t/a;南沙港的藻类养殖面积需要在现有基础上再扩大0.44倍,达到107.52 ha,才可以与网箱养殖系统的氮磷污染负荷构成平衡;网箱养殖个数与藻类养殖面积(ha)的合理配比约为1∶0.027。 相似文献
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动态水流条件下河流底泥污染物(CODCr)释放研究 总被引:1,自引:1,他引:1
为了研究不同水深、流速等水动力条件对底泥中污染物释放强度的影响,以苏州河底泥为例,通过水槽试验,分析了动态水流条件下河流底泥中污染物释放及其对上覆水体水质的影响.结果表明,CODCr释放率随时间的增大而增大,但CODCr释放强度随时间的增大而减小.底泥中污染物释放率与水深和流速有关,在相同水深的条件下,底泥的释放率随着流速的增加而增大;在相同流速的条件下,底泥的释放率随着水深的增大而减小.在水深10cm、流速0.10m.s-1的动态水流条件下,底泥向上覆水体释放CODCr的释放强度与时间的关系为:C=1.06C0e-0.06t. 相似文献
70.
Microbial community functional structure in response to micro-aerobic conditions in sulfate-reducing sulfur-producing bioreactor 总被引:1,自引:0,他引:1
Limited oxygen supply to anaerobic wastewater treatment systems had been demonstrated as an effective strategy to improve elemental sulfur(S0) recovery, coupling sulfate reduction and sulfide oxidation. However, little is known about the impact of dissolved oxygen(DO) on the microbial functional structures in these systems. We used a high throughput tool(GeoChip) to evaluate the microbial community structures in a biological desulfurization reactor under micro-aerobic conditions(DO: 0.02–0.33 mg/L). The results indicated that the microbial community functional compositions and structures were dramatically altered with elevated DO levels. The abundances of dsrA/B genes involved in sulfate reduction processes significantly decreased(p 0.05, LSD test) at relatively high DO concentration(DO: 0.33 mg/L). The abundances of sox and fccA/B genes involved in sulfur/sulfide oxidation processes significantly increased(p 0.05, LSD test) in low DO concentration conditions(DO: 0.09 mg/L) and then gradually decreased with continuously elevated DO levels. Their abundances coincided with the change of sulfate removal efficiencies and elemental sulfur(S0) conversion efficiencies in the bioreactor. In addition, the abundance of carbon degradation genes increased with the raising of DO levels, showing that the heterotrophic microorganisms(e.g., fermentative microorganisms) were thriving under micro-aerobic condition. This study provides new insights into the impacts of micro-aerobic conditions on the microbial functional structure of sulfatereducing sulfur-producing bioreactors, and revealed the potential linkage between functional microbial communities and reactor performance. 相似文献