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121.
农村生活污水治理长效管理机制研究   总被引:3,自引:0,他引:3  
近年来,随着杭州农村生活污水治理工程的全面实施,设施的日常管理维护,保证正常稳定运行、长期发挥应有作用日益成为关注重点.本文在对杭州地区农村生活污水治理现状调研基础上,分析了现有治理工程在规划设计、工程质量、设施运行、日常管理及资金等方面存在的问题,提出了从组织体系、工程项目体系、政策保障体系、资金筹措体系、考核评价体系等方面构建农村生活污水治理长效管理机制.  相似文献   
122.
Monitoring is critical to assess management effectiveness, but broadscale systematic assessments of monitoring to evaluate and improve recovery efforts are lacking. We compiled 1808 time series from 71 threatened and near-threatened terrestrial and volant mammal species and subspecies in Australia (48% of all threatened mammal taxa) to compare relative trends of populations subject to different management strategies. We adapted the Living Planet Index to develop the Threatened Species Index for Australian Mammals and track aggregate trends for all sampled threatened mammal populations and for small (<35 g), medium (35–5500 g), and large mammals (>5500 g) from 2000 to 2017. Unmanaged populations (42 taxa) declined by 63% on average; unmanaged small mammals exhibited the greatest declines (96%). Populations of 17 taxa in havens (islands and fenced areas that excluded or eliminated introduced red foxes [Vulpes vulpes] and domestic cats [Felis catus]) increased by 680%. Outside havens, populations undergoing sustained predator baiting initially declined by 75% but subsequently increased to 47% of their abundance in 2000. At sites where predators were not excluded or baited but other actions (e.g., fire management, introduced herbivore control) occurred, populations of small and medium mammals declined faster, but large mammals declined more slowly, than unmanaged populations. Only 13% of taxa had data for both unmanaged and managed populations; index comparisons for this subset showed that taxa with populations increasing inside havens declined outside havens but taxa with populations subject to predator baiting outside havens declined more slowly than populations with no management and then increased, whereas unmanaged populations continued to decline. More comprehensive and improved monitoring (particularly encompassing poorly represented management actions and taxonomic groups like bats and small mammals) is required to understand whether and where management has worked. Improved implementation of management for threats other than predation is critical to recover Australia's threatened mammals.  相似文献   
123.
卤代烃是大气环境与气候变化研究的热点问题.基于2003 ~2018年在泰山山顶(36.25°N,117.10°E,海拔1534 m)的6期强化观测数据,结合气流轨迹模型与受体源解析模型,分析了华北平原区域背景大气中卤代烃的长期变化趋势和主要来源.结果 表明,《蒙特利尔议定书》已淘汰物种(CFC-12、CFC-11、CF...  相似文献   
124.
杀虫剂及抗生素对发光菌的短期毒性与长期毒性   总被引:4,自引:1,他引:3  
以毒物对青海弧菌Q67 (Vibrio-qinghaiensis sp.-Q67)发光抑制为毒性指标,基于短期微板毒性分析法(S-MTA法),建立了长期微板毒性分析法(L-MTA法),测定了吡虫啉(IMI)、抗蚜威(PIR)、啶虫脒(ACE)及敌百虫(DIP)等4种杀虫剂与氯霉素(CHL)、盐酸四环素(TET)、硫酸链霉素(STR)及硫酸巴龙霉素(PAR)等4种抗生素的短期(15 min)毒性和长期(12 h)毒性.采用短期毒性与长期毒性EC50之比(RSL)为指标,表征同一物质的毒性差异. 结果表明:3种杀虫剂(IMI,ACE及PIR)的短期毒性与长期毒性差异不大(其RSL分别为0.84,0.81和1.11);杀虫剂DIP和2个抗生素(CHL及TET)的短期毒性与长期毒性差异明显(其RSL分别为11.76,9.67及154.38);另2个抗生素(STR和PAR)只有较强的长期毒性.   相似文献   
125.
采用硫酸亚铁为还原剂,粉煤灰为添加剂对铬渣进行固化/稳定化处理,并通过冻融、碳化、模拟酸雨淋溶以及表面浸出实验研究了固化体的长期稳定性。冻融后固化体的质量损失小于1%,强度损失小于10%;碳化后其碳化深度在8mm~15mm之间;抗压强度均大于30Mpa,可用于建筑用途;六价铬的浸出毒性均低于国家标准的1.5mg/L:表明固化体长期稳定性良好,用于填埋,安全、可靠。  相似文献   
126.
This paper provides a comparison of ecosystem management (EM) to the traditional regulatory management approach and outlines the characteristics of EM from a policy perspective, defining the conditions under which this management tool can be successfully implemented. Ecosystem management is a collaborative and integrative tool focused on balancing societal needs, economic growth, and environmental protection to ensure the long-term ecological integrity of a particular ecosystem. The characteristics of this particular tool include: (1) its holistic approach to environmental problems; (2) its integration of values (economic, social, and environmental) through a collaborative, multi-partner, decision making structure; (3) its reliance on science to guide decisions and set boundaries; and (4) its ability to learn from the implementation of decisions (adaptive management). Examples are draw from Environment Canada's various regional ecosystem initiatives.  相似文献   
127.
As part of the European Community Respiratory Health Survey (ECRHS) PM2.5 (particles collected with an upper 50% cut point of 2.5 μm aerodynamic diameter) was measured using an EPA-WINS (Environmetal Protection Agency Well Impactor Ninety-six) sampler. The monitoring schedule was restricted to 7 days per month for one year. Simultaneously, during this one year study period a collocated Harvard Impactor (HI) was run on a daily basis in Erfurt, Germany. Here we validated the reliability of annual, seasonal and monthly means estimated using the ECRHS scheme (measurements taken less than 25% of the whole study period) with the ‘true’ long-term averages, which were estimated using all available daily means.The daily PM2.5 means, obtained by both instruments operated in parallel, were only slightly different (the mean difference between EPA-WINS and HI was 1.8 μg m−3 and 2.8 μg m−3 for the winter means). The values obtained by the two instruments were highly correlated (r = 0.95).In view of that negligible difference, no additional bias was seen with respect to the annual and the winter means estimated by the two different sampling strategies (the difference was 1.7 μg m−3 and 2.7 μg m−3, respectively). Monthly means, however, can only be considered to be a crude estimate that may substantially under- or overestimate the true monthly mean value.  相似文献   
128.
垃圾焚烧飞灰浸出特性   总被引:1,自引:0,他引:1       下载免费PDF全文
利用柱试验研究了我国垃圾焚烧飞灰在过流系统中的浸出特性. 结果表明:在过流系统中,浸出液的pH呈先升后降的趋势,并且在试验后期保持在碱性条件(pH在9.66左右);飞灰中阳离子(Na+,K+,Ca2+)和阴离子(Cl-,SO42-)的浸出主要集中在试验初期(第96 天),使初期浸出液含盐量很高;柱试验中4种重金属的浸出质量浓度〔ρ(Cd),ρ(Pb),ρ(Cu)和ρ(Cr)〕远低于批试验,但试验前期浸出液中的重金属浸出质量浓度相对较高;当浸取时间超过120 d时,虽然浸出液中重金属浸出质量浓度明显降低,但仍有一定量的重金属不断浸出.   相似文献   
129.
利用自行开发的混合呼吸速率测量仪在接种污泥的条件下对重庆某城市污水处理厂污水进行了呼吸速率测试(短期BOD测试,以呼吸速率测量重新进入内源呼吸阶段为结束);同时应用美国产BI-2000电解质呼吸仪在不接种污泥的条件下对该污水进行了BOD测试(长期BOD测试,理论上以污水中所有有机物矿化为结束)。对2种测试方法及其结果进行了比较,结果表明,2种方法得到的BCOD存在很大差异,短期BOD测试方法得到的结果仅为长期BOD测试方法得到的结果的40%~60%。通过批式呼吸测量方法测定了原废水中的活性异养微生物浓度XH(0),结果表明,XH(0)与BCODst之和与BCODlt比较接近,两者之比在0.88~1.02之间,平均值为0.94。  相似文献   
130.
矿化垃圾基本理化性状剖面变化特征研究   总被引:1,自引:0,他引:1  
矿化垃圾能否作为农业资源被重新利用,除应考虑有效植物营养物质的含量与是否存在有害物质外,还取决于其基本理化性状。对城市生活垃圾填埋场中经填埋6年、8年、10年后得到的矿化垃圾基本物化性状变化特征进行分析,结果表明:矿化垃圾的土粒密度显著小于对照土壤,交换性盐基总量、CEC显著大于对照土壤,pH值和对照土壤基本相当;表层(0~50 cm)矿化垃圾的土粒密度、CEC、交换性盐基总量、pH值的变化幅度依次大于中层(50~100 cm)和下层(100~150 cm);矿化垃圾的理化性状在填埋8~10年后总体趋于稳定。从植物生长的环境角度看,填埋8~10年后的矿化垃圾可以开采后作为植物生长基质、土壤改良剂等农业资源化利用。  相似文献   
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