全文获取类型
收费全文 | 756篇 |
免费 | 105篇 |
国内免费 | 62篇 |
专业分类
安全科学 | 248篇 |
废物处理 | 8篇 |
环保管理 | 234篇 |
综合类 | 222篇 |
基础理论 | 70篇 |
环境理论 | 5篇 |
污染及防治 | 19篇 |
评价与监测 | 26篇 |
社会与环境 | 46篇 |
灾害及防治 | 45篇 |
出版年
2024年 | 1篇 |
2023年 | 12篇 |
2022年 | 18篇 |
2021年 | 26篇 |
2020年 | 21篇 |
2019年 | 32篇 |
2018年 | 27篇 |
2017年 | 48篇 |
2016年 | 46篇 |
2015年 | 40篇 |
2014年 | 40篇 |
2013年 | 40篇 |
2012年 | 47篇 |
2011年 | 69篇 |
2010年 | 40篇 |
2009年 | 62篇 |
2008年 | 34篇 |
2007年 | 54篇 |
2006年 | 44篇 |
2005年 | 25篇 |
2004年 | 29篇 |
2003年 | 17篇 |
2002年 | 18篇 |
2001年 | 13篇 |
2000年 | 15篇 |
1999年 | 17篇 |
1998年 | 11篇 |
1997年 | 12篇 |
1996年 | 6篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有923条查询结果,搜索用时 453 毫秒
171.
172.
Karimov Bakhtiyor Lieth Helmut Kurambaeva Mohira Matsapaeva Irina 《Mitigation and Adaptation Strategies for Global Change》2005,10(1):87-103
The main objective of this paper is the presentation of water scarcity and water quality problems of fishery and fishermen in the southern Aral Sea region Kazakhstan. We tried in the past to inform interested people about our suggestions how to rehabilitate the situation, how to produce relatively enough fish for the functioning of local fish processing industry and to give people jobs, but we were unable so far to convince decision makers about innovations needed. It is essential therefore to reiterate some of the well-known problems of the region, called the Aral Sea crisis, but we concentrate mostly on the problems for the fishermen. While we do this, we understand, however, that the problem requires solution within the concept of a socioeconomic sustainable development for which we suggest the development of a decision support system based upon a computer simulation model providing optimal solutions. 相似文献
173.
厦门海域防控陆源污染的实践与经验 总被引:2,自引:0,他引:2
在分析厦门海域主要污染物来源的基础上,总结了厦门市针对不同来源的水污染物开展的治理措施,并重点介绍了厦门市关于化工废水、电镀废水、生活污水和养殖废水的处理与利用的4个典型实例.厦门市在防治陆源污染的实践中,逐渐形成并发挥重要作用的5项机制,即管理机制、组织协调机制、法规保障机制、科技进步机制、经济激励机制. 相似文献
174.
本文介绍了预应力锚杆在衡阳市107国道K8 451~641段边坡加固治理中的应用,其成功地控制了已滑动的山体,避免了滑坡的发展,取得了良好的工程效果. 相似文献
175.
Predicting freshwater organisms based on machine learning is becoming more and more reliable due to the availability of appropriate datasets, advanced modelling techniques and the continuously increasing capacity of computers. A database consisting of measurements collected at 360 sampling sites in non-navigable watercourses in Flanders was applied to predict the absence/presence of benthic macroinvertebrate taxa by means of decision trees. The measured variables were a combination of physical–chemical (temperature, pH, dissolved oxygen concentration, conductivity, total organic carbon, Kjeldahl nitrogen and total phosphorus), structural (granulometric analysis of the sediment, width, depth and flow velocity of the river) and two ecotoxicological variables. The predictive power of decision trees was assessed on the basis of the number of Correctly Classified Instances (CCI). A genetic algorithm was introduced to compare the predictive power of different sets of input variables for the decision trees. The number of input variables was reduced from 15 to 2–8 variables without affecting the predictive power of the decision trees significantly. Furthermore, reducing the number of input variables allowed to ease the identification of general data trends. 相似文献
176.
Using GIS for siting artificial reefs—Data issues, problems and solutions: ‘Real World’ to ‘Real World’ 总被引:1,自引:0,他引:1
As GIS becomes an increasingly more ‘user-friendly’ tool, and more people recognize the benefits of the technology in their
work environment, inevitably greater use will be made of it for a wide range of applications. The ease with which a GIS can
now be used often overshadows the complexity underlying this technology and the potential difficulties that can (and do) arise
when this is not fully understood. In practice, there are two routes open to the application of GIS technology for environmental
studies. The first is to commission new data for the research. The second is to make use of existing data sets. Data are at
the heart of any GIS application. A detailed knowledge about the data sources, the method of collection, capture, scale and
sampling strategy, especially if the data are to be used in any analysis, modelling or simulation studies, is fundamental
to any application. Unfortunately, information about data (metadata) is seldom available, especially for archival or legacy
data sets. Furthermore, although it is now relatively easy to acquire digital data, to input, store, manipulate and display
this data, and to output the results of any GIS analysis in the practical sense, little consideration is given to the problems
associated with data quality and how this will ultimately affect present and future analyses and use of the output for planning
and decision-making. The need to raise awareness about data quality for applications is set in the context of the development
of an environmental database for the Moray Firth. Northeast Scotland, and more specifically the use of selected data sets
from the database to aid in the proposed siting of an artificial reef. Using this example, this contribution explores the
problems associated with the use of both existing analog and digital data sets as the basis for environmental applications,
the problems of data acquisition, data quality, data standards, error and how these can affect the operational use of the
data in GIS analyses. The solution to such problems appears to lie with improved error assessment and reporting. The outcome
of this contribution is an attempt to offer guidance and solutions to researchers and applications specialists undertaking
similar studies, by suggesting to what extent studies, such as the artificial reef siting, can safely make use of existing
data sets without risking the problems associated with judgements based on inadequate information, and generated or inherent
error. 相似文献
177.
We use a mechanism design framework to analyze the optimal design of green payment policies with the dual goals of conservation and income support for small farms. Each farm is characterized by two dimensions of attributes: farms size and conservation efficiency. The policymaker may not be able to use the attributes as an explicit criterion for payments. We characterize optimal policy when conservation efficiency is unobservable to policymakers, and when farm size is also unobservable. An income support goal is shown to reduce the conservation distortion caused by asymmetric information. The cost of optimal green payment mechanisms is shown to depend crucially on whether large or small farms have greater conservation efficiency. 相似文献
178.
丰丽林 《湖南环境生物职业技术学院学报》2007,13(3):53-55
运用位移监控信息、土体平衡原理、护壁桩支撑设计原理指导深基坑支护适应基坑深度变大的难题,具有施工方便、经济、安全的、工期短等特点,为在闹市区深基坑支护施工提供了经验.图1,表1,参7. 相似文献
179.
180.
介绍了动态式多准则离散型决策模型原理、求解方法以及在国家环境质量决策支持系统(简称NEQDSS)中的应用开发。结果证明,该模型及其软件在NEQDSS中的应用是极其成功的。 相似文献