首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   404篇
  免费   34篇
  国内免费   101篇
安全科学   12篇
废物处理   12篇
环保管理   72篇
综合类   285篇
基础理论   64篇
污染及防治   32篇
评价与监测   12篇
社会与环境   45篇
灾害及防治   5篇
  2024年   3篇
  2023年   7篇
  2022年   9篇
  2021年   13篇
  2020年   4篇
  2019年   10篇
  2018年   10篇
  2017年   16篇
  2016年   13篇
  2015年   14篇
  2014年   16篇
  2013年   41篇
  2012年   32篇
  2011年   39篇
  2010年   12篇
  2009年   13篇
  2008年   6篇
  2007年   29篇
  2006年   28篇
  2005年   28篇
  2004年   20篇
  2003年   16篇
  2002年   22篇
  2001年   11篇
  2000年   21篇
  1999年   17篇
  1998年   16篇
  1997年   17篇
  1996年   8篇
  1995年   10篇
  1994年   4篇
  1993年   15篇
  1992年   5篇
  1991年   2篇
  1990年   4篇
  1989年   2篇
  1988年   1篇
  1987年   2篇
  1986年   1篇
  1985年   1篇
  1982年   1篇
排序方式: 共有539条查询结果,搜索用时 171 毫秒
251.
Abstract

Many local authorities use standardized environmental management systems (EMSs) to improve their environmental management. These authorities often find it difficult to manage environmental impact caused by their exercise of authority i.e. indirect environmental impact (IEI) within their EMSs. Since this is connected to their core activities, it is important to understand how IEI could be more efficiently managed with respect to EMS work. The purpose for this paper is to study if and how IEI could be managed within the framework of EMS. In this study we have identified two different approaches to managing IEI. Because managing IEI is complex, it is often ignored when initiating EMSs or managed by explicitly avoid mentioning the concept. Managing IEI is seen as a matter of maturity within the organization. The paper concludes with a discussion regarding a developed definition of IEI and how management of IEI could be facilitated.  相似文献   
252.
ABSTRACT

This study examines a community garden in Copenhagen, Denmark, "The Urban Integration Gardens" that endeavours to strengthen social integration in the local multicultural neighbourhood. The "community" in the gardens is explored, with a focus on how they foster social capital, particularly opportunities for "bridging" social capital. A mixed-methods approach is used, by employing a qualitative analysis of gardeners’ perceptions of "community", diversity and inclusivity, through the lens of "cognitive" social capital, and the meanings the gardeners assign to their experiences, and how they understand their involvement in the gardens. We also examine "structural" dimensions of social capital, involving quantitative data from a questionnaire and data from Statistics Denmark, comparing data concerning socio-demographic backgrounds from gardeners and residents in the local neighbourhood and Copenhagen. Major findings include that the garden generates both bonding and bridging "cognitive" social capital, and the gardeners consistently agreed that the garden has a strong community, and is permeated by diversity and inclusivity. Nonetheless, data from Denmark’s Statistics Office reveal that the garden does not "represent" the diversity in the neighbourhood regarding the distribution of members with a Western/non-Western background, as well as social class. This suggests that endeavours to involve co-citizens with non-Western backgrounds and gardeners with lower social status are restrained by potential structural barriers, which limits the "width" of bridging social capital in the garden.  相似文献   
253.
It is increasingly clear that a wide range of stakeholders should be included in the problem formulation phase of research aimed at solving environmental problems; indeed the inclusion of stakeholders at this stage has been formalized as an integral part of ecological risk assessment. In this paper, we advocate the additional inclusion of stakeholders in the refinement of research methods and protocols and in the execution of the research, rather than just at the final communication and reporting phase. We use a large study of potential radionuclide levels in marine biota around Amchitka Island as a case study. Amchitka Island, in the Aleutian Island Chain of Alaska, was the site of three underground nuclear tests (1965-1971). The overall objective of the biological component of the study was to collect a range of marine biota for radionuclide analysis that could provide data for assessing current food safety and provide a baseline for developing a plan to monitor human and ecosystem health in perpetuity. Stakeholders, including regulators (State of Alaska), resource trustees (US Fish and Wildlife Service, State of Alaska), representatives of the Aleut and Pribilof Island communities, the Department of Energy (DOE), and others, were essential for plan development. While these stakeholders were included in the initial problem formulation and approved science plan, we also included them in the refinement of protocols, selection of bioindicators, selection of a reference site, choice of methods of collection, and in the execution of the study itself. Meetings with stakeholders resulted in adding (or deleting) bioindicator species and tissues, prioritizing target species, refining sampling methods, and recruiting collection personnel. Some species were added because they were important subsistence foods for the Aleuts, and others were added because they were ecological equivalents to replace species deleted because of low population numbers. Two major refinements that changed the research thrust were (1) the inclusion of Aleut hunters and fishers on the biological expedition itself to ensure that subsistence foods and methods were represented, and (2) the addition of a fisheries biologist on a NOAA research trawler to allow sampling of commercial fishes. Although the original research design called for the collection of biota by Aleut subsistence fishermen, and by a commercial fishing boat, the research was modified with continued stakeholder input to actually include Aleuts and a fisheries biologist on the expeditions to ensure their representation. The inclusion of stakeholders during the development of protocols and the research itself improved the overall quality of the investigation, while making it more relevant to the interested and affected parties. Final responsibility for the design and execution of the research and radionuclide analysis rested with the researchers, but the process of stakeholder inclusion made the research more valuable as a source of credible information and for public policy decisions.  相似文献   
254.
云南省矿产资源开发利用中的主要环境问题   总被引:1,自引:0,他引:1  
云南省矿产资源丰富,随着矿产资源开发规模的增大,所引起的环境污染、环境资源破坏和矿山地质灾害日益突出。环境污染多出现在岩溶地区,以水污染为主;环境资源的破坏以露采区最为严重,对土地资源、植被、地貌景观有较大的影响,甚至对地质灾害的发生都有深刻影响;矿山地质灾害的发生,地质地貌背景是诱发的潜在因素,不合理的开采方法是诱发的主导因素,降雨和水文条件是激发灾难发生的直接原因。云南矿产资源开发中最常见的地质灾害主要有滑坡、泥石流和地面塌陷、地裂缝等,所造成的危害和损失也比较突出。不同类型的地质灾害在使用露天开采和地下开采不同采矿方法的矿山发生的频率和强度也不尽相同。采用实例来阐述矿产资源开发过程中所引发的主要环境问题,对云南矿山地质灾害的现状进行分析。  相似文献   
255.
在调查及收集大龙滩泉资料基础上,分析了泉的水文地质特征,采用泉流量衰减方程进行了水资源评价,表明岩溶含水系统具有一定的调蓄能力;参照GB 8537—2008《饮用天然矿泉水标准》,该泉锶含量2.42 mg/L,达到了锶矿泉水的指标标准;为确保该泉口取水安全,应对泉溢流口做全封闭处理,隔断地表污水影响。  相似文献   
256.
运用原子吸收火焰发射光谱法对矿泉水中锂离子含量进行测定,并做回收率实验,对整个测量过程的不确定度来源进行了分析,并按照国际通用方法对不确定度各个分量进行了评定和合成,得到原子吸收火焰发射法测定矿泉水中锂离子的不确定度评定。结果表明:原子吸收法火焰发射测定矿泉水中锂离子的不确定度的主要来源是回收率测定和标准溶液配制。采用本方法测定的矿泉水中的锂离子的扩展不确定度为0.69μg/L  相似文献   
257.
环境矿物材料在水体污染治理中的应用受到了人们的广泛关注.本文综述了环境矿物材料的改性方法,主要介绍了物理改性,主要有水热改性和焙烧改性,化学改性主要有无机改性和有机改性,探讨了在水体污染治理中的应用研究现状,主要包括去除重金属离子、去除有机污染物、去除无机阴离子和去除其他污染物,给出了环境矿物材料的发展趋势,主要包括加强环境矿物材料的研究、加强改性方法的研究和拓展与其他方法的联用等方面的应用研究.  相似文献   
258.
王兴润  农泽喜  王琪 《环境科学》2012,33(12):4412-4416
研究了含砷废渣高温烧结过程引起的砷挥发和砷发生的矿物相结构变化,并分析了烧结体的砷浸出释放行为.在10MPa下加压成型制样,进空气流量为2 000 mL·min-1,烧结温度1 000~1 350℃,烧结时间60 min.结果表明,烧结温度对砷挥发的影响很小,As的固定率保持在90%以上,但对砷浸出毒性的影响明显.烧结温度低于1 000℃时,FeAsS被氧化生成钙砷、铝砷和铁砷,以Ca3(AsO4)2矿物相为主,导致砷的浸出释放水平提高;烧结温度达到1 200℃,Ca3(AsO4)2被玻璃熔融态所包围,并被转换为硅钙砷酸盐化学键接,导致砷的浸出水平显著降低.从烧结体的环境安全性考虑,最佳烧结温度为1 200℃.  相似文献   
259.
The pollution characteristic of polycyclic aromatic hydrocarbons(PAHs) in common used mineral oils, semi-refined oils, refined oils and solid wastes produced during the used mineral oil regeneration process was analyzed. The results showed that total PAHs content in six common used mineral oils was as follows: used engine oil used quenching oil used casting oil used hydraulic oil used antirust oil used industrial lubricating oil. Furthermore, this order was dependent on the source of PAHs and oil working temperatures. Additionally, total PAHs content in regenerated oils was as follows: semi-refined oil refined oil crude oil, which was related to the catalytic cracking process of crude oil and adsorption refining process of semi-refined oil. The ranking of total PAHs content in regenerated wastes varied depending on the regeneration technology used as follows: waste adsorption sand acid sludge waste clay precipitation sludge cracked residue. In all types of used mineral oils and regenerated wastes, the maximum and minimum proportions of the total PAHs content were composed of 2–3 ring-PAHs and 5–6 ring-PAHs, respectively. The majority of PAHs in the used mineral oils entered into regenerated wastes during regeneration process, while a small number remained in the regenerated oil.  相似文献   
260.
Construction and demolition (C&D) waste, being already the largest waste fraction in industrialized countries, is expected to increase in the future. C&D waste recycling has been considered to be a valuable option not only for minimizing C&D waste streams to landfills but also for mitigating primary mineral resource depletion. Even though the use of recycled mineral construction materials (RMCM) is regulated and successful application examples are available, construction stakeholders do not yet broadly apply them. Although various criteria hindering a transition towards a broader application of RMCM have been identified, it is yet unknown how these criteria differ among decisions, stakeholders and applications. We therefore analyze construction stakeholders’ behavior, and decision-making regarding RMCM for the construction material market in Switzerland. Stakeholders’ decision-making was quantified with the analytical hierarchy process (AHP) in a survey in combination with their behavior. The results demonstrate the importance of stakeholder interaction, i.e. most stakeholders decide which material to apply based on interaction with other stakeholders e.g., recommendations and specifications. However, the initial general specification by awarding authorities that construction should be sustainable has little relevance to the subsequent material decisions. On the contrary the role of the recommendation of engineers, have a high impact on the subsequent decisions by the other stakeholders. Results also confirm that RMCM are broadly accepted in civil engineering (CE), whereas in structural engineering (SE) RMCM are still a niche product. The good alignment of the outcome of decision modeling with observed behavior shows the usefulness of analyzing decision-making with AHP.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号