全文获取类型
收费全文 | 882篇 |
免费 | 89篇 |
国内免费 | 106篇 |
专业分类
安全科学 | 194篇 |
废物处理 | 33篇 |
环保管理 | 220篇 |
综合类 | 301篇 |
基础理论 | 127篇 |
污染及防治 | 61篇 |
评价与监测 | 36篇 |
社会与环境 | 57篇 |
灾害及防治 | 48篇 |
出版年
2024年 | 5篇 |
2023年 | 12篇 |
2022年 | 32篇 |
2021年 | 44篇 |
2020年 | 39篇 |
2019年 | 39篇 |
2018年 | 28篇 |
2017年 | 46篇 |
2016年 | 55篇 |
2015年 | 49篇 |
2014年 | 35篇 |
2013年 | 81篇 |
2012年 | 62篇 |
2011年 | 55篇 |
2010年 | 50篇 |
2009年 | 49篇 |
2008年 | 40篇 |
2007年 | 60篇 |
2006年 | 44篇 |
2005年 | 31篇 |
2004年 | 21篇 |
2003年 | 32篇 |
2002年 | 25篇 |
2001年 | 17篇 |
2000年 | 21篇 |
1999年 | 18篇 |
1998年 | 13篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 10篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有1077条查询结果,搜索用时 125 毫秒
291.
P. B. L. Tamuno G. Howard M. D. Smith 《Environment, Development and Sustainability》2009,11(4):887-903
The Central Niger Delta is made up of a network of rivers and creeks that constitute the inland surface waters. These surface
waters have historically influenced settlement patterns and are of diverse use to residents of the Central Niger Delta. Surface
water like many ecological system are complex, whose complexity has been associated with seasonal variability. Traditional
knowledge (TK), traditional ecological knowledge (TEK) and the traditional eco-livelihood knowledge (TELK) of residents of
four rural communities in the Central Niger Delta have been explored in developing a river use profile of rural communities
of the Central Niger Delta. A questionnaire survey has been carried out in four communities, two each from the Otuoke and
Kolo Creeks. The result shows that river use varies across seasons and affected by: physico-chemical water quality and characteristics
of surface water; the hydrological characteristics; the biological/ecological characteristics; cultural use and demand; need
for development projects; and access to this vital resource. Fishing constitute one of the major livelihood source in the
Central Niger Delta and the TELK of fishers in the sample communities have specifically been explored to understanding fishing
patterns across seasons. The five seasons identified from this study are: flood season; flood recession season; dry season;
early rainy season; and rainy season. Therefore, the thesis of this paper is that there is the need to balance the current
usage of surface water in the developing world such as the Central Niger Delta with the demand for development as well as
future use if development is to meet the criteria for equitable development. The river use profile could be a promising tool
in planning for equitable development.
相似文献
M. D. SmithEmail: |
292.
Toward knowledge structuring of sustainability science based on ontology engineering 总被引:1,自引:1,他引:0
Terukazu Kumazawa Osamu Saito Kouji Kozaki Takanori Matsui Riichiro Mizoguchi 《Sustainability Science》2009,4(1):99-116
In sustainability science (SS), it is difficult to identify what needs to be solved, and it is also not clear how to solve the problems that are identified. There has been no consensus on the underlying question of “What is structuring knowledge in SS?” This paper focuses on knowledge structuring accompanied by supporting of thinking. It addresses the key challenges associated with knowledge structuring in SS, identifies the requirements for the structuring of knowledge, proposes a reference model, and develops an ontology-based mapping tool as a solution to one layer of the reference model. First, we identify the important requirements for SS knowledge structuring. Second, we develop a reference model composed of five layers based on three of the requirements. Third, we develop an ontology-based mapping tool at Layer 2 of the reference model for meeting the two major challenges for SS, namely, identifying what problems should be addressed in SS itself and proposing solutions for those problems. The tool is designed to store and retrieve information regarding SS, to provide access to a prototype ontology for SS, and to create multiple maps of conceptual chains depending on a user’s interests and perspectives. Finally, we assess whether the developed tool successfully realizes the targeted part of the reference model for SS by examining the tool’s conformity to the reference model, as well as its usability, effectiveness, and constraints. Although several issues were identified in the prototype ontology and the mapping tool, the study concluded that the mapping tool is useful enough to facilitate the function of Layer 2. In particular, the mapping tool can support thinking about SS from the viewpoint of: (a) finding new potentials and risks of technological countermeasures studied in SS; (b) helping users to get a more comprehensive picture of problems and their potential solutions; and (c) providing an effective opportunity to come up with new ideas that might not be thought of without such a tool. 相似文献
293.
This paper assesses the Bluff oyster fishery in New Zealand as a case study in common pool resource management. It discusses ways in which modern information technology, augmented by low-tech data gathering strategies and community ethnography, can be used to produce an integrated scientific and local knowledge-inspired fishery database that lends itself to fostering collaboration in resource management and planning. The specific context and state of the oyster fishery in Bluff are described. Issues regarding undocumented and ephemeral intergenerational knowledge, much of which is geospatial in nature, on the fishery, the current crisis that many see in the future of the fishery, and a lack of cohesion or common sense of purpose between the stakeholder groups are discussed. It is argued that the digital resource that results from the integration of local and scientific knowledge and the potential community building processes that can ensue from collaboration and dialogue around this centrepiece are of central importance in developing an oyster fishery management plan that is holistic in concept and sustainable in purpose. 相似文献
294.
水样品中汞砷联合测定的研究--氢化物发生原子荧光光谱法 总被引:10,自引:0,他引:10
利用氢化物发生-原子荧光分析技术(HG-AFS)对水样品中汞、砷联合测定方法进行了有益的探索.通过一系列条件实验,设定出了合理有效的水样前处理方法、仪器测定条件以及主要试剂的浓度.并对其最低检出下限、精密度和准确度进行了评估,结果表明该方法用于环境水样品中汞、砷元素的同时测定具有很好的可行性和适用性. 相似文献
295.
以1991~2013年CNKI数据库收录的2 263篇国内水资源管理研究核心期刊论文为数据来源,利用文献计量学引文网络分析工具CiteSpace,绘制国内水资源管理研究的知识图谱。分析了我国水资源管理研究的时间分布、机构力量分布、作者分布、期刊分布、学科和基金分布以及研究热点和趋势。〖JP2〗结果显示:中国科学院和中国水利水电等科研系统实力较强,水利水电工程学、资源科学、环境科学与资源利用是文献分布的主要学科,国家自然科学基金、国家重点基础研究发展计划(973)等是主要基金来源,宏观层面的水资源管理制度和政策研究、流域综合管理和水资源的经济属性等是目前的研究热点,最严格水资源管理制度和水生态文明建设等内容将是未来一段时间的主题 相似文献
296.
L. Star E. D. Ellen K. Uitdehaag F. W. A. Brom 《Journal of Agricultural and Environmental Ethics》2008,21(2):109-125
The combination of breeding for increased production and the intensification of housing conditions have resulted in increased
occurrence of behavioral, physiological, and immunological disorders. These disorders affect health and welfare of production
animals negatively. For future livestock systems, it is important to consider how to manage and breed production animals.
In this paper, we will focus on selective breeding of laying hens. Selective breeding should not only be defined in terms
of production, but should also include traits related to animal health and welfare. For this we like to introduce the concept
of robustness. The concept of robustness includes individual traits of an animal that are relevant for health and welfare.
Improving robustness by selective breeding will increase (or restore) the ability of animals to interact successfully with
the environment and thereby to make them more able to adapt to an appropriate husbandry system. Application of robustness
into a breeding goal will result in animals with improved health and welfare without affecting their integrity. Therefore,
in order to be ethically acceptable, selective breeding in animal production should accept robustness as a breeding goal.
L. Star, E. D. Ellen contributed equally to this work. Star belongs to the Adaptation Physiology Group, Wageningen University,
and the rest of the authors belong to the Animal Breeding and Genomics Centre, Wageningen University. 相似文献
297.
In this paper, we investigate the Precautionary Principle (PP) in action. Precaution is a fairly new concept in environmental
policy. It emerged back in the 1960s but did not consolidate until the 1980s, as it formed part of the major changes taking
place in environmental policies at that time. The PP is examined in three contexts. Firstly, we look at the meaning of the
concept and how it is disseminated through the media and public discourses to the political arenas of Denmark. Then we examine
how the idea is adopted to the political level. Thirdly, we look briefly at the first Danish translation of the principle
into a practical context, which includes translations into concrete scientific practices. It is concluded that if the PP shall
be more than a simple “idea” or a frequently used “term,” emphasis must be put on the transformation of the concept into concrete
practices, like e.g., the alternative testing regimes that we show in the case of plant growth-retarding pesticides presented
in this paper. 相似文献
298.
299.
300.
系统动力学方法在城市生活垃圾产生系统的应用 总被引:6,自引:0,他引:6
准确预测城市生活垃圾产生量是构建与运行生活垃圾管理系统的首要条件. 我国大部分城市生活垃圾的历史统计数据稀缺,传统预测方法往往难以得到要求精度的预测结果. 在系统地分析生活垃圾产生量影响因素及因素间互动关系的基础上,建立了基于VENSIM软件的系统动力学模型,并将该模型应用于深圳市城市生活垃圾产生系统. 结果表明:运用系统动力学方法可以较好地进行城市生活垃圾产生量预测,解决了数据稀缺条件下城市生活垃圾产生量的精确预测问题,为处理处置工艺的选择和规模的确定提供了数据支撑,同时可以在垃圾产生量预测的基础上进行不同政策下系统的行为模拟. 相似文献