全文获取类型
收费全文 | 22057篇 |
免费 | 2008篇 |
国内免费 | 4894篇 |
专业分类
安全科学 | 1691篇 |
废物处理 | 391篇 |
环保管理 | 4633篇 |
综合类 | 13444篇 |
基础理论 | 3688篇 |
环境理论 | 47篇 |
污染及防治 | 1372篇 |
评价与监测 | 2183篇 |
社会与环境 | 1250篇 |
灾害及防治 | 260篇 |
出版年
2024年 | 103篇 |
2023年 | 405篇 |
2022年 | 587篇 |
2021年 | 714篇 |
2020年 | 713篇 |
2019年 | 679篇 |
2018年 | 675篇 |
2017年 | 971篇 |
2016年 | 1118篇 |
2015年 | 1154篇 |
2014年 | 1227篇 |
2013年 | 1816篇 |
2012年 | 1699篇 |
2011年 | 1708篇 |
2010年 | 1352篇 |
2009年 | 1287篇 |
2008年 | 1024篇 |
2007年 | 1460篇 |
2006年 | 1442篇 |
2005年 | 1184篇 |
2004年 | 1027篇 |
2003年 | 1004篇 |
2002年 | 836篇 |
2001年 | 763篇 |
2000年 | 730篇 |
1999年 | 512篇 |
1998年 | 390篇 |
1997年 | 366篇 |
1996年 | 319篇 |
1995年 | 322篇 |
1994年 | 222篇 |
1993年 | 197篇 |
1992年 | 132篇 |
1991年 | 128篇 |
1990年 | 92篇 |
1989年 | 73篇 |
1988年 | 56篇 |
1987年 | 48篇 |
1986年 | 37篇 |
1985年 | 22篇 |
1984年 | 33篇 |
1983年 | 28篇 |
1982年 | 34篇 |
1981年 | 34篇 |
1980年 | 41篇 |
1979年 | 40篇 |
1978年 | 24篇 |
1977年 | 23篇 |
1975年 | 21篇 |
1973年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
991.
Z. Aslıgül Göçmen James A. LaGro Jr. 《Journal of Environmental Planning and Management》2016,59(8):1513-1535
Smart growth and sustainability planning have, in recent years, become central issues in planning discourse. Scholars have argued that planning capacity at the local government level is critical for smart growth planning, and that planners have a fundamental role to play in advancing local and regional sustainability. In this paper, we investigate the extent to which local planning capacity enables communities to promote more sustainable, smart growth residential development. Based on a 2013 survey of 38 county and 53 municipal governments in the state of Wisconsin, USA, this study finds that the majority of the sample communities have permitted residential developments characterized as transit-oriented, New Urbanist, mixed use, infill developments, or conservation subdivisions as alternatives to low-density, automobile-dependent conventional developments. The study also finds that jurisdictions with higher planning capacities are more likely to overcome significant barriers to more sustainable residential development. 相似文献
992.
993.
994.
Trace element concentrations were studied in soils of the King George and Elephant islands in the maritime part of West Antarctica. The lowest concentrations of Cu, Pb, Cd, Zn, Ni and Mn were typical for the pristine soil of Elephant Island. The highest concentrations of these elements were found in the Fildes Peninsula and revealed the influence of human activities in the area of the Bellingshausen station and adjacent waste disposal sites. Ornithogenic soils of the Fildes Peninsula have shown low concentrations of Cd and As. Using geoaccumulation indexes, all the pristine soils of King George and Elephant islands and ornithogenic soils of the Fildes Peninsula were classified as unpolluted; the human-affected soils were mainly identified as moderately polluted. Obtained data can be used as background concentration levels for further researches. 相似文献
995.
介绍了江苏省重污染天气监测预报预警系统以及大气重污染预警会商流程,将2015年13个地级市的模式预报、人工预报结果分别与实际观测值进行比较。结果表明:人工预报更准确,PM_(2.5)日均值、臭氧日最大8 h平均值、AQI 3个指标人工预报和实况的相关性分别比模式预报高出12.8%、0.3%、11.4%,平均标准误差(MNE)分别低20.7%、3.1%、23.1%。依据国家空气质量预报技术指南评分办法,对各市2015年全年空气质量级别为"良"时进行评分。通过开展07∶00预报更新,使2015年上半年空气质量预报级别得分平均提高了0.9分,全年级别得分平均提高了2.6分;通过改进模式预报参数,使PM_(2.5)日均预报值、臭氧日最大8 h平均预报值、AQI预报值和实际观测值的相关性比上年同期分别提高26.0%、5.0%、33.9%,MNE分别降低3.6%、31.3%、7.6%。 相似文献
996.
建立了烟尘、烟气监测全程序质量监督体系,确定了监督检查工作需要控制的环节,并细化了各环节需要重点关注的内容。以层次分析法等关键技术为基础,通过赋予监测全过程各环节不同的指标权重,建立了统一化、标准化的综合评价模式。研究将评价体系分为2个层次,一级指标3个,二级指标19个,并确定了每个指标的测评内容及计算方法。将该体系应用于6家监测机构的质量监督工作,证明其实用性和适用性良好。 相似文献
997.
Christian Brandstätter David Laner Roman Prantl Johann Fellner 《Waste management (New York, N.Y.)》2014,34(12):2537-2547
Municipal solid waste landfills pose a threat on environment and human health, especially old landfills which lack facilities for collection and treatment of landfill gas and leachate. Consequently, missing information about emission flows prevent site-specific environmental risk assessments. To overcome this gap, the combination of waste sampling and analysis with statistical modeling is one option for estimating present and future emission potentials. Optimizing the tradeoff between investigation costs and reliable results requires knowledge about both: the number of samples to be taken and variables to be analyzed.This article aims to identify the optimized number of waste samples and variables in order to predict a larger set of variables. Therefore, we introduce a multivariate linear regression model and tested the applicability by usage of two case studies. Landfill A was used to set up and calibrate the model based on 50 waste samples and twelve variables. The calibrated model was applied to Landfill B including 36 waste samples and twelve variables with four predictor variables.The case study results are twofold: first, the reliable and accurate prediction of the twelve variables can be achieved with the knowledge of four predictor variables (Loi, EC, pH and Cl). For the second Landfill B, only ten full measurements would be needed for a reliable prediction of most response variables. The four predictor variables would exhibit comparably low analytical costs in comparison to the full set of measurements. This cost reduction could be used to increase the number of samples yielding an improved understanding of the spatial waste heterogeneity in landfills.Concluding, the future application of the developed model potentially improves the reliability of predicted emission potentials. The model could become a standard screening tool for old landfills if its applicability and reliability would be tested in additional case studies. 相似文献
998.
西部大开发十五年环境效率评价及其影响因素分析 总被引:1,自引:0,他引:1
西部大开发政策实施以来,西部地区实现了快于东部和中部的经济增长。正确认识西部地区经济增长中的环境成本,评价西部地区的环境效率具有重要意义。本文运用考虑非期望产出的超效率SBM模型测算了2000—2014年西部大开发以来的环境效率。研究发现:西部地区环境效率偏低,处于相对无效状态。西部地区环境效率明显低于传统效率,经济增长付出了较高的环境代价。西部大开发以来传统效率与环境效率之间的差距呈现先扩大后缩小的"倒U"型走势变化。西部地区省份环境效率在全国排名靠后,各省份的环境效率呈现出差异化的发展态势,其中重庆和四川排名不断提升,新疆排名逐步回落,内蒙古和广西在西部地区排名相对靠前且比较稳定,云南和陕西一直处于中间水平,贵州、甘肃、青海、宁夏排名相对靠后。西部地区环境效率2000—2003年上升,2004—2010年不断下降,2010—2014年趋于平稳。西部地区环境效率低于东部地区且差距大,也低于中部地区和全国平均水平。通过收敛性检验发现,西部地区各省份间的环境效率差距呈现先缩小后扩大的趋势;西部地区与东部地区间的环境效率差距逐渐扩大,与中部地区间的环境效率差距先扩大后缩小。本文同时采用了Tobit模型进行面板回归,实证分析了西部地区环境效率的影响因素。结果表明:经济发展水平、科学技术水平、能源消费结构、环保投资力度对西部地区环境效率具有显著影响;产业结构变化和对外开放程度对西部地区环境效率影响不显著;西部地区存在环境效率的库兹涅茨曲线。 相似文献
999.
‘Fracking’ was on New York's agenda since 2008, yet no decision was made about it until late 2014. The gridlock is an intriguing puzzle given that the Marcellus shale is considered a ‘world class’ energy supply, and development has been aggressive in other US states. While policy scholars typically conceptualize gridlock as policy stability, this paper examines it as a dynamic process by which competing discourse coalitions engage in interactive framing processes that (re)structure the discussion. This suggests that the interaction between contending coalitions influences gridlock. Yet, we lack knowledge about interactive framing between competing coalitions during policy controversies. Our main finding is that a central mechanism of gridlock is the production of conflict through interactive framing dynamics that deny a shared discursive space capable of ushering in a consensus, or reasoned agreement. In New York, this contest evolved from a policy consensus about the economic benefits of fracking to policy negotiation that incorporated environmental threats, and to prolonged policy controversy in which competing discourse coalitions contested notions of fracking in relation to energy production, environmental protection, public health, economic development, and governance. While a ban has been instituted, the failure to bridge discourse coalitions suggests that controversy will persist unless meaning disputes are resolved. 相似文献
1000.
由于经济社会的发展伴随的环境问题越来越复杂,资源相对不足、环境容量有限越来越突出,环境管理转型问题引起越来越多的国内外学者关注。所谓环境管理转型,是指环境管理思维、策略和方式的转变,是以环境质量为目标导向,从被动应对向主动防控的转变。本文通过文献梳理的方法,综述了国内外学术界对于环境管理战略进行的多角度探讨。通过综述发现,国外学者主要注重环境管理理论研究,如环境管理的模型研究和不同环境管理战略的研究,且国外学者在研究不同环境管理战略时,研究对象多为微观层面的企业组织;而我国学者的研究则主要集中在宏观层面,即从国家的角度来探讨环境管理战略如何完成转型,从而促进我国经济社会的良性发展。现有的国内外研究是环境管理战略相关理论发展和实践推行的重要基础,在环境管理战略研究领域,本文认为还有一些问题需要进一步研究:一是环境管理的转型不仅需要宏观层面的统筹、微观方面的变革,也需要从中观层面来推进,所以中观层面的环境管理研究同样具有重要的现实意义。二是环境管理的转型不仅需要法律手段的支撑、经济手段的配置,也需要公民环保意识的觉醒,所以关于公民环保意识层面的研究也需要加强。 相似文献