全文获取类型
收费全文 | 771篇 |
免费 | 89篇 |
国内免费 | 92篇 |
专业分类
安全科学 | 84篇 |
废物处理 | 23篇 |
环保管理 | 238篇 |
综合类 | 340篇 |
基础理论 | 102篇 |
环境理论 | 1篇 |
污染及防治 | 38篇 |
评价与监测 | 52篇 |
社会与环境 | 44篇 |
灾害及防治 | 30篇 |
出版年
2024年 | 3篇 |
2023年 | 7篇 |
2022年 | 26篇 |
2021年 | 25篇 |
2020年 | 15篇 |
2019年 | 30篇 |
2018年 | 20篇 |
2017年 | 43篇 |
2016年 | 53篇 |
2015年 | 35篇 |
2014年 | 59篇 |
2013年 | 68篇 |
2012年 | 58篇 |
2011年 | 68篇 |
2010年 | 48篇 |
2009年 | 45篇 |
2008年 | 45篇 |
2007年 | 55篇 |
2006年 | 36篇 |
2005年 | 37篇 |
2004年 | 26篇 |
2003年 | 23篇 |
2002年 | 22篇 |
2001年 | 21篇 |
2000年 | 15篇 |
1999年 | 11篇 |
1998年 | 9篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 3篇 |
1994年 | 7篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有952条查询结果,搜索用时 359 毫秒
11.
科技期刊发展方向确定了科技期刊的定位。社会定位是意识形态定位;经济定位是期刊走向问题;读者定位、编辑定位、管理定位是办刊的方法和手段。 相似文献
12.
孔繁德 《中国环境管理干部学院学报》2003,13(4):5-10
我国城市竞争力研究成果表明秦皇岛市综合竞争力在全国排序第39位,基础设施、环境、区位等硬竞争力较强,而企业管理、制度、文化等软竞争力较弱,因此虽然在河北省名列前茅,但在沿海城市中比较落后,为了增强城市竞争力,必须正确定位、协调发展;发挥优势、加快发展;加快招商引资;进一步开放;加快科技进步,加强精神文明建设;强化城市营销和品牌建设;强化城市和企业管理。 相似文献
13.
Anne Ingeborg Myhr Terje Traavik 《Journal of Agricultural and Environmental Ethics》2003,16(3):227-247
Risk governance of GM plants and GMfood products is presently subject to heatedscientific and public controversies. Scientistsand representatives of the biotechnologyindustry have dominated debates concerningsafety issues. The public is suspicious withregard to the motives of scientists, companies,and political institutions involved. Thedilemmas posed are nested, embracing valuequestions, scientific uncertainty, andcontextual issues. The obvious lack of data andinsufficient information concerning ecologicaleffects call for application of thePrecautionary Principle (PP). There are,however, divergent opinions among scientistsabout the relevance of putative hazards,definition of potential ``adverse effects,' andwhether actions should be taken to preventharm. The reliance on the concept ofsubstantial equivalence in safety evaluation ofGM food is equally controversial. Consequently,value assumptions embedded in a scientificframework may be a barrier for employment ofthe PP. One of our major conclusions is thatprecautionary GMP usage requires riskassessment criteria yet undeveloped, as well asbroader and more long-term conceptions of risk,uncertainty, and ignorance. Conflicts ofinterest and public participation are otherissues that need to be taken intoconsideration. GMP governance regimes that arejustifiable from a precautionary and ethicalpoint of view must transcend traditionalscientific boundaries to include alternativescientific perspectives as well as publicinvolvement. 相似文献
14.
Peggy A. Johnson Thomas M. Heil 《Journal of the American Water Resources Association》1996,32(6):1283-1291
ABSTRACT: Bankfull depth and discharge are basic input parameters to stream planform, stream restoration, and highway crossing designs, as well as to the development of hydraulic geometry relationships and the classification of streams. Unfortunately, there are a wide variety of definitions for bankfull that provide a range of values, and the actual selection of bankfull is subjective. In this paper, the relative uncertainty in determining the bankfull depth and discharge is quantified, first by examining the variability in the estimates of bankfull and second by using fuzzy numbers to describe bankfull depth. Fuzzy numbers are used to incorporate uncertainty due to vagueness in the definition of bankfull and subjectivity in the selection of bankfull. Examples are provided that demonstrate the use of a fuzzy bankfull depth in sediment trans. port and in stream classification. Using fuzzy numbers to describe bankfull depth rather than a deterministic value allows the engineer to base designs and decisions on a range of possible values and associated degrees of belief that the bankfull depths take on each value in that range. 相似文献
15.
综合防尘技术在煤矿的应用实践 总被引:5,自引:0,他引:5
张仙保 《中国安全生产科学技术》2006,2(3):78-80
粉尘严重威胁矿井安全生产和职工身体健康。公司依靠科学管理,完善了各项综合防尘管理制度,制定了一系列综合防尘方面的管理规定和防尘技术操作规程;加强技术创新,重点抓好综采、综掘工作面以及回风系统和定点尘源的装置,实行自动控制等综合防尘技术;从管理和技术创新角度,通过采用减少粉尘产生、降尘、排尘、除尘、个体防尘等综合防尘技术措施应用实践,取得了良好的效果。 相似文献
16.
本文主要论述了在实现我国中长期环境与资源保护战略目标过程中,环境形势的长期性、艰巨性和复杂性;指出必须通过发展观念、经济增长方式、经济体制和政策职能的转变,树立和落实全面、协调和可持续的科学发展观,促进经济、政治、文化、生态环境的全面发展。 相似文献
17.
总结经验,进一步推进全国循环经济发展 总被引:4,自引:1,他引:4
作者全面阐述了当前我国发展循环经济的重要性、存在的问题,并提出了下一步工作的意见。 相似文献
18.
Karsten Klint Jensen 《Journal of Agricultural and Environmental Ethics》2004,17(4-5):405-423
The 2000 BSE Inquiry report points out that the most serious failure of the UK Government was one of risk communication. This paper argues that the government's failure to communicate the risks BSE posed to humans to a large degree can be traced back to a lack of transparency in the first risk assessment by the Southwood Working Party. This lack of transparency ensured that the working party's risk characterization and recommendations were ambiguous and thus hard to interpret. It also meant that uncertainties were not addressed in a satisfactory way. In the recommendations, the attitude to uncertainty was implicit rather than explicit.The risk communication based on the report amplified these flaws. Most importantly, it did not address the uncertainty at all. Apparently, the reason for this was fear of overreaction by the public. However, the result was counter-productive, because the risk communication did not then appear trustworthy. Later risk assessments and risk communication omitted to correct these flaws. Indeed, the fact that, following receipt of new information, advisory experts and policy makers had changed their views of the risk to humans was never clearly communicated to the public. There seemed to be little faith in the public's ability to reach a balanced judgment regarding the uncertainties.In the concluding section of the paper, this analysis is compared with the food standards agency's (FSA's) approach to BSE. The intervention of this agency was seen as one of the more important efforts to restore consumer confidence in British beef. And the agency certainly appears to be committed to openness and to addressing scientific uncertainty. However, using the risk of BSE in sheep as a case study, the paper shows that transparency – i.e., the clear presentation of factual and normative claims and assumptions underlying advice, and openness about the reasoning based on these claims and assumptions – is less than fully achieved in the FSA's work. 相似文献
19.
Helen M. Regan Clara I. Bohórquez David A. Keith Tracey J. Regan Kurt E. Anderson 《Conservation biology》2017,31(2):459-468
Population viability analysis (PVA) is a reliable tool for ranking management options for a range of species despite parameter uncertainty. No one has yet investigated whether this holds true for model uncertainty for species with complex life histories and for responses to multiple threats. We tested whether a range of model structures yielded similar rankings of management and threat scenarios for 2 plant species with complex postfire responses. We examined 2 contrasting species from different plant functional types: an obligate seeding shrub and a facultative resprouting shrub. We exposed each to altered fire regimes and an additional, species‐specific threat. Long‐term demographic data sets were used to construct an individual‐based model (IBM), a complex stage‐based model, and a simple matrix model that subsumes all life stages into 2 or 3 stages. Agreement across models was good under some scenarios and poor under others. Results from the simple and complex matrix models were more similar to each other than to the IBM. Results were robust across models when dominant threats are considered but were less so for smaller effects. Robustness also broke down as the scenarios deviated from baseline conditions, likely the result of a number of factors related to the complexity of the species’ life history and how it was represented in a model. Although PVA can be an invaluable tool for integrating data and understanding species’ responses to threats and management strategies, this is best achieved in the context of decision support for adaptive management alongside multiple lines of evidence and expert critique of model construction and output. 相似文献
20.
Conservation decision makers commonly use project‐scoring metrics that are inconsistent with theory on optimal ranking of projects. As a result, there may often be a loss of environmental benefits. We estimated the magnitudes of these losses for various metrics that deviate from theory in ways that are common in practice. These metrics included cases where relevant variables were omitted from the benefits metric, project costs were omitted, and benefits were calculated using a faulty functional form. We estimated distributions of parameters from 129 environmental projects from Australia, New Zealand, and Italy for which detailed analyses had been completed previously. The cost of using poor prioritization metrics (in terms of lost environmental values) was often high—up to 80% in the scenarios we examined. The cost in percentage terms was greater when the budget was smaller. The most costly errors were omitting information about environmental values (up to 31% loss of environmental values), omitting project costs (up to 35% loss), omitting the effectiveness of management actions (up to 9% loss), and using a weighted‐additive decision metric for variables that should be multiplied (up to 23% loss). The latter 3 are errors that occur commonly in real‐world decision metrics, in combination often reducing potential benefits from conservation investments by 30–50%. Uncertainty about parameter values also reduced the benefits from investments in conservation projects but often not by as much as faulty prioritization metrics. 相似文献