全文获取类型
收费全文 | 745篇 |
免费 | 27篇 |
国内免费 | 43篇 |
专业分类
安全科学 | 40篇 |
废物处理 | 3篇 |
环保管理 | 247篇 |
综合类 | 179篇 |
基础理论 | 139篇 |
污染及防治 | 72篇 |
评价与监测 | 66篇 |
社会与环境 | 56篇 |
灾害及防治 | 13篇 |
出版年
2023年 | 8篇 |
2022年 | 19篇 |
2021年 | 27篇 |
2020年 | 19篇 |
2019年 | 14篇 |
2018年 | 11篇 |
2017年 | 21篇 |
2016年 | 33篇 |
2015年 | 33篇 |
2014年 | 25篇 |
2013年 | 67篇 |
2012年 | 29篇 |
2011年 | 56篇 |
2010年 | 25篇 |
2009年 | 52篇 |
2008年 | 48篇 |
2007年 | 61篇 |
2006年 | 29篇 |
2005年 | 27篇 |
2004年 | 26篇 |
2003年 | 26篇 |
2002年 | 25篇 |
2001年 | 18篇 |
2000年 | 35篇 |
1999年 | 15篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 17篇 |
1995年 | 10篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有815条查询结果,搜索用时 46 毫秒
91.
Maintenance of Forest Biodiversity in a Post-Soviet Governance Model: Perceptions by Local Actors in Lithuania 总被引:1,自引:1,他引:0
Successful biodiversity conservation does not depend on ecologic knowledge alone. Good conservation policies and policy implementation
tools are equally important. Moreover, the knowledge, skills, and attitudes of local actors, directly in charge of operations
in the field, are a key to successful policy implementation. The connections between policy objectives and their implementation
as well as the involvement of local actors’ efforts in implementing policy objectives largely depend on the governance model
in use. This article assesses the knowledge of local actors in relation to the biodiversity conservation objectives and tools
in Lithuanian forest management. As a main framework for this study, the needs assessment approach was applied. The study
used both in-depth open-ended interviews and follow-up telephone interviews. Two state forest enterprises in Lithuania were
selected as the study sites. The findings indicate that policy objectives in the field of forest biodiversity conservation
and the related tools are well known but not well understood by those in charge of forest biodiversity policy implementation.
To improve the situation, a transition toward adaptive learning and participatory governance as a means of facilitating conservation
efforts is proposed. 相似文献
92.
A Social Analysis of the Bioinvasions of Dreissena polymorpha in Spain and Hydrilla verticillata in Guatemala 总被引:1,自引:0,他引:1
Human agency plays a key role in the processes of biological invasions. This comprises not only the human role in the configuration of driving forces or in the perception of the impacts, but also the conceptualization of alien species themselves as an environmental problem. This paper examines different stakeholders' positions in bioinvasion processes at different scales, and it looks at their relevance for the management of invasive species. It compares two cases: the invasion process of Dreissena polymorpha in the Ebro River in Spain and the case of Hydrilla verticillata in Lake Izabal, Guatemala. Our results are structured according to impacts and to management options. The discussion focuses on the relevance of incorporating the different stakeholders' interests and values in the analysis and management of biological invasions. Although social analysis of stakeholders' positions is necessary in order to foster management actions, it also reveals conflicts on the relevant criteria and on the very definition of invasive species. 相似文献
93.
基于内容分析法的河流健康内涵及表征 总被引:2,自引:1,他引:2
运用内容分析法对近10~15年中外文献中有影响力的36个河流健康概念进行分析,经过样本选取、指标提取、量化处理等过程提炼出最频繁出现的能代表其内涵的6个标准,即:维持结构完整性、自然生态功能发挥、满足人类社会合理需求、处于良好状态、河流管理工具和目标、建立河流基准状态。基于此,对河流健康概念进行了重新架构:河流健康是指河流生态系统特定的良好状况,可以作为河流基准状态以及河流管理的目标,在这一状态下,河流生态系统能够维持其生态系统结构完整性,充分发挥其自然生态功能,并满足人类社会合理需求,提供相应的社会服务功能。通过对30个有关河流健康表征指标及评价方法的文献进行分析,识别生物指标、水质参数、形态结构、河床底质、水文条件以及河岸带状况等是目前使用最广泛的6个指标,指出河流健康的表征指标及评价标准应根据区域特征、人类活动影响以及功能定位而有所差异。 相似文献
94.
Ecosystem service concepts can offer a valuable approach for linking human and nature, and arguments for the conservation and restoration of natural ecosystems. Despite an increasing interest in the topic, the application of these concepts for water resource management has been hampered by the lack of practical definitions and methodologies. In this study we review and analyse the current literature and propose an approach for assessing and valuing ecosystem services in the context of water management. In particular, to study the link between multiple pressures, ecological status and delivery of ecosystem services in aquatic ecosystems under different scenarios of measures or future changes. This is of interest for the development of River Basin Management Plans under the EU Water Framework Directive. We provide a list of proxies/indicators of natural capacity, actual flow and social benefit for the biophysical assessment of the ecosystem services. We advocate the use of indicators of sustainability, combining information on capacity and flow of services. We also suggest methods for economic valuation of aquatic ecosystem for each service and spatial scale of application. We argue that biophysical assessment and economic valuation should be conducted jointly to account for the different values of ecosystem services (ecologic, social and economic) and to strengthen the recognition of human dependency on nature. The proposed approach can be used for assessing the benefits of conservation and restoration of aquatic ecosystems in the implementation of the EU water policy. 相似文献
95.
V. N. Vtorova 《Russian Journal of Ecology》2004,35(5):296-302
Variation in the content of N, P, K, Ca, Mg, Na, Cu, Zn, Mn, and Fe has been analyzed in the needles of 19 spruce species growing in the natural and urbanized ecosystems of Siberia and Central Asia. The results have shown that similarity in the content of biophilic elements in one-year-old needles of different species is conditioned by biochemical processes, which confirms the status of these species as passive bioindicators of environmental quality. The contents of trace elements in perennial needles, except color variations of chlorophyll, deserve further study as prospective indicators of environmental quality. 相似文献
96.
97.
M. Fehr K.A. Sousa A.F.N. Pereira L.C. Pelizer 《Environment, Development and Sustainability》2004,6(3):355-366
The research related here focuses on municipal situations where problems of sustainability may be defined and tackled on the basis of bottom-up management procedures with the participation of organized society. The aim is to build management models that may be implemented with reasonable administrative effort and cost. Implementation pursues the target of approaching a sustainable situation in the municipality. Environmental parameters for an ideal municipality with undefined geographical location are presented. For each parameter, a set of indicators is developed that can measure the prospect of sustainability. The indicators are defined in terms of numbers or literal concepts according to the possibility of measurement. Examples of management models are presented, which are able to approach the situation defined as sustainable by the indicators. The basic management tool is the learning curve of targeted communities, which is experimentally developed and applied. The indicators are grouped according to their range of applicability. 相似文献
98.
“Measuring Sustainability”: A Multi-Criterion Framework 总被引:4,自引:0,他引:4
So far, the elementary question of whether one country’s or region’s economy is moving towards sustainability or away from it cannot be answered with unanimous consensus on the ‘measuring rod(s)’ to be employed. The main assumption of this article is that sustainability assessment needs a set of multi-dimensional indicators. From this assumption a question arises: how could such indicators be aggregated? Often, some indicators improve while others deteriorate. For instance, when incomes grow, SO2 might go down while CO2 increases. It has to be noted that this is the classical conflictual situation studied in multi-criteria decision theory. The use of a multi-criterion framework for making operational the ‘measuring of sustainability’ is discussed here by means of illustrative examples and more formal arguments. 相似文献
99.
Reductions in global bee populations are threatening the pollination benefits to both the planet and people. Whilst the contribution of bee pollination in promoting sustainable development goals through food security and biodiversity is widely acknowledged, a range of other benefits provided by bees has yet to be fully recognised. We explore the contributions of bees towards achieving the United Nation’s Sustainable Development Goals (SDGs). Our insights suggest that bees potentially contribute towards 15 of the 17 SDGs and a minimum of 30 SDG targets. We identify common themes in which bees play an essential role, and suggest that improved understanding of bee contributions to sustainable development is crucial for ensuring viable bee systems. 相似文献
100.
Juan Carlos Moreno Saiz Felipe Domínguez Lozano Manuel Marrero Gómez Ángel Bañares Baudet 《Conservation biology》2015,29(3):910-919
The International Union for Conservation of Nature (IUCN) Red List Index (RLI) is used to measure trends in extinction risk of species over time. The development of 2 red lists for Spanish vascular flora during the past decade allowed us to apply the IUCN RLI to vascular plants in an area belonging to a global biodiversity hotspot. We used the Spanish Red Lists from 2000 and 2010 to assess changes in level of threat at a national scale and at the subnational scales of Canary Islands, Balearic Islands, and peninsular Spain. We assigned retrospective IUCN categories of threat to 98 species included in the Spanish Red List of 2010 but absent in the Spanish Red List of 2000. In addition, we tested the effect of different random and taxonomic and spatial Spanish samples on the overall RLI value. From 2000 to 2010, the IUCN categories of 768 species changed (10% of Spanish flora), mainly due to improved knowledge (63%), modifications in IUCN criteria (14%), and changes in threat status (12%). All measured national and subnational RLI values decreased during this period, indicating a general decline in the conservation status of the Spanish vascular flora. The Canarian RLI value (0.84) was the lowest, although the fastest deterioration in conservation status occurred on peninsular Spain (from 0.93 in 2000 to 0.92 in 2010). The RLI values based on subsamples of the Spanish Red List were not representative of RLI values for the entire country, which would discourage the use of small areas or small taxonomic samples to assess general trends in the endangerment of national biotas. The role of the RLI in monitoring of changes in biodiversity at the global and regional scales needs further reassessment because additional areas and taxa are necessary to determine whether the index is sufficiently sensitive for use in assessing temporal changes in species’ risk of extinction. 相似文献