全文获取类型
收费全文 | 757篇 |
免费 | 105篇 |
国内免费 | 240篇 |
专业分类
安全科学 | 39篇 |
废物处理 | 15篇 |
环保管理 | 50篇 |
综合类 | 573篇 |
基础理论 | 80篇 |
污染及防治 | 99篇 |
评价与监测 | 188篇 |
社会与环境 | 19篇 |
灾害及防治 | 39篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 17篇 |
2021年 | 22篇 |
2020年 | 23篇 |
2019年 | 20篇 |
2018年 | 42篇 |
2017年 | 47篇 |
2016年 | 54篇 |
2015年 | 59篇 |
2014年 | 70篇 |
2013年 | 68篇 |
2012年 | 82篇 |
2011年 | 66篇 |
2010年 | 57篇 |
2009年 | 78篇 |
2008年 | 72篇 |
2007年 | 54篇 |
2006年 | 67篇 |
2005年 | 32篇 |
2004年 | 28篇 |
2003年 | 38篇 |
2002年 | 27篇 |
2001年 | 16篇 |
2000年 | 9篇 |
1999年 | 13篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1988年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有1102条查询结果,搜索用时 0 毫秒
941.
广州市2002~2003年空气污染指数分析 总被引:7,自引:1,他引:7
根据广州市2002年1月1日至2003年12月31日的空气污染指数资料,对广州市每日的空气污染指数和可吸入颗粒物、NO2和SO2的污染指数、空气污染指数的月平均值和年平均值、空气质量级别、首要污染物等指标进行了统计分析.结果表明,广州市的空气污染状况与大尺度的天气现象如季风和降雨量等密切相关. 相似文献
942.
城市合流污水A2/O处理系统中TTC-ETS活性监测研究 总被引:2,自引:0,他引:2
研究了温度和F/M的变化对A2/O系统TTC-ETS活性的影响,分析了TTC-ETS活性与COD降解的相关关系;通过低C/N冲击下TTC-ETS活性和理化指标的比较,讨论了以TTC-ETS活性表征系统运行状况的优劣.结果表明,一定范围内,温度与F/M均与TTC-ETS活性成正相关,TTC-ETS活性(TF/TSS.t)变化范围约13.2~48.3 mg/(g.h),最大值约为60 mg/(g.h);TTC-ETS活性与COD去除率相关性显著,并且TTC-ETS活性可预警系统的异常状态,当TTC-ETS活性为41.0 mg/(g.h)时,COD去除效率最高. 相似文献
943.
Janis A. Shandro Marcello M. Veiga Jean Shoveller Malcolm Scoble Mieke Koehoorn 《Resources Policy》2011,36(2):178-186
The health of mining communities is becoming a priority for the mining industry, governments, and researchers. This paper describes an exploratory qualitative study into community health issues and mining activities (associated with the mining boom-bust cycle) from the perspective of health and social service providers in the northern Canadian coal mining community of Tumbler Ridge, British Columbia. Health and social service providers report on increases in pregnancies, sexually transmitted infections, and mine related injuries during booming mine activities. During bust times, mental health issues such as depression and anxiety were reported. Overarching community health issues prominent during both boom and bust periods include burdens to health and social services, family stress, violence towards women, and addiction issues. This paper concludes by providing recommendations as to how the industry can enhance community health made by this important stakeholder group. 相似文献
944.
Contini D Gambaro A Belosi F De Pieri S Cairns WR Donateo A Zanotto E Citron M 《Journal of environmental management》2011,92(9):2119-2129
The direct influence of ship traffic on atmospheric levels of coarse and fine particulate matter (PM2.5, PM10) and fifteen polycyclic aromatic hydrocarbons (PAHs) has been estimated in the urban area of Venice. Data analysis has been performed on results collected at three sites over the summer, when ship traffic is at a maximum. Results indicate that monitoring of the PM daily concentrations is not sufficiently detailed for the evaluation of this contribution, even though it could be useful for specific markers such as PAHs. Therefore a new methodology, based on high temporal resolution measurements coupled with wind direction information and the database of ship passages of the Harbour Authority of Venice has been developed. The sampling sites were monitored with optical detectors (DustTrack® and Mie pDR-1200) operating at a high temporal resolution (20s and 1s respectively) for PM2.5 and PM10. PAH in the particulate and gas phases were recovered from quartz fibre filters and polyurethane foam plugs using pressurised solvent extraction, the extracts were then analysed by gas chromatography- high-resolution mass spectrometry. Our results shows that the direct contribution of ships traffic to PAHs in the gas phase is 10% while the contribution to PM2.5 and to PM10 is from 1% up to 8%. 相似文献
945.
土岩界面地震波能量传递与耗散特性研究——以汶川8.0级地震为例 总被引:1,自引:0,他引:1
以汶川8.0级地震为例,应用应力波在弹性介质界面能量分配与反射和透射系数之间的相关性,得出地震波在不同介质中滞留能量的耗散比与介质波阻抗比和上层介质能量衰减比之间的关系。通过离散数值计算发现当能量衰减比一定时,两种介质的波阻抗比在某一特定值时上层介质滞留能量耗散比达到最大,该值随着能量衰减比的增大而增大。这一结论对地震山区的"剥皮型"滑坡提供了一种全新的解释,并得到了路堤工程宏观震害与面波测试资料的验证。 相似文献
946.
《International Journal of Sustainable Engineering》2013,6(1):28-39
It has been argued in recent years that Western economies need to increase their resource productivity by 90% over the next 50 years. This is a radical aim. This paper draws on design for sustainability (DfS) thinking to scope interventions that encourage greater levels of resource productivity through reconfiguring concepts of growth and well‐being within organisational strategies, structures, systems, processes and outputs. Based on research from a UK EPSRC funded project Design Dialogues (2005–2008), this paper links together sustainable design and innovation literatures and dialogue‐based primary research that together inform the development of an approach to innovation for sustainability. The emphasis on sustainable innovation is to understand what is designed (the outputs of business) and why (the inputs: the values, beliefs, visions and objectives) within a context of ecological limits. The foundations of this approach are introduced here in order to demonstrate the potential to provoke a new way of thinking about longer‐term organisational innovation through making explicit the intrinsic connections between natural and human capitals. This paper explores the need to think differently in order to create sustainability and presents the outcome of this research: a methodology for innovation for sustainability. 相似文献
947.
应用阿克苏市国家基准站及2个环保局监测站2015年大风沙尘天气过程前后PM10浓度变化及其与污染源、NECP全球再分析资料、风、监测站周边环境等关系进行分析.结果表明,阿克苏市春季沙尘天气的首要污染物均为PM10,PM10的变化曲线呈正态分布,春季中度及以上污染日均出现在污染日当日或次日.造成阿克苏市沙尘天气污染源分本地型、外来型以及二者共同影响型三种.本地型沙尘污染强度取决于北风风速大小及强风持续时间,PM10浓度变化与风速呈正相关.而外来型污染多发生在本地型沙尘天气之后,"东灌"冷空气裹挟沙尘进入南疆盆地,造成地面加压,浮尘天气造成PM10浓度增大,并持续数天.总结出沙尘天气污染预警的几个必要条件,后续在地区环保局、县局监测站建立的情况下,为分析阿克苏地区"八县一市"污染物与气象因素的关系提供借鉴,同时为实际的空气质量预警提供参考. 相似文献
948.
在焦作、安阳、开封、三门峡、信阳5个城市开展PM_(10)手工标准方法和自动监测法比对实验,并用相关性和相对偏差对比对结果进行分析和评价。结果表明:12015年5个城市采集的PM_(10)手工和自动监测值均具有良好的相关性。22015年5个城市采集的PM_(10)手工和自动监测值的相对偏差为-19.1%~9.68%;负偏差数据占总数据量的75%。3PM_(10)手工和自动监测值|RD|平均值在中浓度下最小,高浓度下最大,低浓度介于二者之间,说明在高浓度和低浓度时PM_(10)的监测数据质量尤其值得关注。 相似文献
949.
Vinícius Marcilio‐Silva Márcia C. M. Marques Jeannine Cavender‐Bares 《Conservation biology》2018,32(5):1074-1084
Trade‐offs in ecosystem services (ES) have received increasing attention because provisioning services often come at the expense of biodiversity loss. When land‐use patterns are not maximally efficient relative to productivity, provisioning services, such as crop production, can often be increased without losing biodiversity. The Atlantic Forest (AF) encompasses dense, mixed, and seasonal forests and has high levels of endemism and anthropogenic threat. We examined trade‐offs between biodiversity and crop production in the AF to provide insights into land‐use management decisions. We developed a biodiversity metric that combines information on tree species richness, evolutionary distinctiveness, and rarity at the local level. We examined the extent to which the nature of ES trade‐offs differ among the 3 forest types. We assessed how annual deforestation rates and land management practices affect biodiversity and agricultural revenues. Finally, we tested whether it is possible to achieve the same total regional revenue without reducing biodiversity by improving local management practices. The 3 forest types had similar patterns in ES trade‐offs, although within mixed forest patterns differed. Biodiversity appeared to be more sensitive to land‐use change than crop revenues. Certain crops yielded up to 10 times higher values in some sites. Enhanced crop productivity may increase revenues without reducing biodiversity. Our results showed that to enhance human well‐being without further conversion of AF, maximizing crop productivity is needed . Increasing efficiency of management outcomes by maintaining higher biodiversity and increasing provisioning services depends on knowledge of forest type, the comparative advantage of planting crops in the best places, and preserving species in a balanced manner across forests. 相似文献
950.
运用生态系统能量10%定律,在浑善达克沙地退化生态系统,按照高级营养级能量需求,在实验区域1%的土地上建立了高产高效饲料基地,以向上一营养级(草食动物)提供足够的能量。结果表明,牲畜的压力逐步向高效地(小范围的土地)集中,而大面积的退化草地(99%),在围栏保护后借助自然力逐步恢复。群落生物量、平均高度和总盖度2年后均随恢复时间增加而增加(P<0.05)。植被组成方面,恢复前固定沙地以冷蒿(Artemisiafrigida)、糙隐子草(Cleistogenssquarrosa)和寸草苔(Carexduriuscula)等为主,恢复2年后冰草(Agropyronmichnoi)、木地肤(Kochiaprostrata)等占优势;滩地植被中,羊草(Leymuschinensis)、披碱草(Elymusdahuricus)等逐步取代了灰绿藜(Chenopodiumglaucum)和尖头叶藜(Chenopodiumacumi-natum)等,优质牧草比例提高。生态恢复不仅使自然生态系统得以保护,而且带动了社会经济的发展,项目中的正蓝旗巴音胡舒嘎查牧民,在实验示范以前后,由每年每户投入1万元买草养畜转变为每户得到2万斤优质牧草;幼畜成活率约提高10%;产奶量100%,牧民收入提高了32%。实验表明,高产高效基地建成后,生态系统能量流动趋于稳定,占试验区域71%的退化草地得到了恢复,从而带动了该地的可持续发展。 相似文献