全文获取类型
收费全文 | 3089篇 |
免费 | 85篇 |
国内免费 | 190篇 |
专业分类
安全科学 | 144篇 |
废物处理 | 15篇 |
环保管理 | 747篇 |
综合类 | 1260篇 |
基础理论 | 199篇 |
污染及防治 | 276篇 |
评价与监测 | 581篇 |
社会与环境 | 107篇 |
灾害及防治 | 35篇 |
出版年
2024年 | 4篇 |
2023年 | 45篇 |
2022年 | 45篇 |
2021年 | 70篇 |
2020年 | 96篇 |
2019年 | 48篇 |
2018年 | 48篇 |
2017年 | 85篇 |
2016年 | 107篇 |
2015年 | 119篇 |
2014年 | 137篇 |
2013年 | 152篇 |
2012年 | 126篇 |
2011年 | 235篇 |
2010年 | 85篇 |
2009年 | 229篇 |
2008年 | 196篇 |
2007年 | 197篇 |
2006年 | 148篇 |
2005年 | 124篇 |
2004年 | 115篇 |
2003年 | 116篇 |
2002年 | 100篇 |
2001年 | 86篇 |
2000年 | 83篇 |
1999年 | 80篇 |
1998年 | 78篇 |
1997年 | 59篇 |
1996年 | 42篇 |
1995年 | 52篇 |
1994年 | 64篇 |
1993年 | 38篇 |
1992年 | 24篇 |
1991年 | 18篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 7篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1969年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有3364条查询结果,搜索用时 0 毫秒
991.
The water reuse applications are becoming increasingly important in Turkey due to fresh water scarcity problems. However, the success of reuse practices depends on the public's acceptance. Therefore, this study was designed to determine the public awareness, and the potential for acceptance, of reuse applications in Turkey by way of a survey carried out for this purpose. 500 questionnaires were sent to different regions of Turkey and 375 of them were returned. The study indicated that both women and men have concerns about usage of wastewater, especially regarding the use of treated wastewater as drinking water. Results also showed that the area of greatest concern among the public is the health risks associated with recycled water. Respondents of both genders felt that treated wastewater reuse for applications not involving close personal contact was acceptable, due to reduced health risk concerns. On the other hand, the cost of reclamation is another major public concern. 相似文献
992.
针对沈阳市水土流失现状、成因及对策进行了初步探讨 ,并对沈阳市水土流失现状 ,提出了防治对策和措施 ,着重强调了政府的政策导向在综合防治水土流失中的重要作用 相似文献
993.
Polycentric networks of formal organizations and informal stakeholder groups, as opposed to centralized institutional hierarchies, can be critically important for strengthening the capacity of governance systems to adapt to unexpected social and biophysical change. Adaptive governance is one type of environmental governance characterized by the emergence of networks that stimulate adaptive capacity through increases in social-learning, communication, trust, public participation and adaptive management. However, detecting and analyzing adaptive governance networks remains elusive, especially given contexts of highly contested resource governance such as large-scale negotiations over water use. Research methods such as social network analysis (SNA) are often infeasible as they necessitate collecting in-depth and politically sensitive personal data from a near-complete set of actors or organizations in a network. Here we present a method for resolving this problem by describing the results of an institutional SNA aimed at characterizing the changing governance network in the Klamath River Basin, USA during a period of contested negotiations over water. Through this research, we forward a method of institutional SNA useful when an individual or egocentric approach to SNA is problematic for political, logistical or financial reasons. We focus our analysis on publically available data signaling changes in formal relationships (statutory, regulatory, contractual) between organizations and stakeholder groups. We find that employing this type of SNA is useful for describing potential and actual transitions in governance that yield increases in adaptive capacity to respond to social and biophysical surprises such as increasing water scarcity and changes in water distribution. 相似文献
994.
Positive polarotaxis in a mayfly that never leaves the water surface: polarotactic water detection in Palingenia longicauda (Ephemeroptera) 总被引:1,自引:2,他引:1
Tisza mayflies, Palingenia longicauda (Olivier 1791), swarm exclusively over the river Tisza (from which the name of the mayfly was derived). This river is bordered
by a high vertical wall of trees and bushes, which hinder P. longicauda to move away horizontally from the water. During swarming, Tisza mayflies fly immediately above the river in such a way that
their cerci touch the water frequently or sweep its surface. This continuous close connection with water and the vertical
wall of the shore and riparian vegetation result in that Tisza mayflies never leave the water surface; consequently, they
need not search for water. Several Ephemeroptera species move away far from water and return to it guided by the horizontal
polarization of water-reflected light. To reveal whether also P. longicauda is or is not polarotactic, we performed a field experiment during the very short swarming period of Tisza mayflies. We show
here that also P. longicauda has positive polarotaxis, which, however, can be observed only under unnatural conditions, when the animals are displaced
from the water and then released above artificial test surfaces. P. longicauda is the first species in which polarotactic water detection is demonstrated albeit it never leaves the water surface, and
thus, a polarotactic water detection seems unnecessary for it. The polarotactic behaviour of Tisza mayflies explains the earlier
observation that these insects swarm above wet asphalt roads running next to river Tisza. 相似文献
995.
Carly Hansen Javad Shafiei Shiva Spencer McDonald April Nabors 《Journal of the American Water Resources Association》2019,55(4):964-975
Streamflow monitoring in the Colorado River Basin (CRB) is essential to ensure diverse needs are met, especially during periods of drought or low flow. Existing stream gage networks, however, provide a limited record of past and current streamflow. Modeled streamflow products with more complete spatial and temporal coverage (including the National Water Model [NWM]), have primarily focused on flooding, rather than sustained drought or low flow conditions. Objectives of this study are to (1) evaluate historical performance of the NWM streamflow estimates (particularly with respect to droughts and seasonal low flows) and (2) identify characteristics relevant to model inputs and suitability for future applications. Comparisons of retrospective flows from the NWM to observed flows from the United States Geological Survey stream gage network over 22 years in the CRB reveal a tendency for underestimating low flow frequency, locations with low flows, and the number of years with low flows. We found model performance to be more accurate for the Upper CRB and at sites with higher precipitation, snow percent, baseflow index, and elevations. Underestimation of low flows and variable model performance has important implications for future applications: inaccurate evaluations of historical low flows and droughts, and less reliable performance outside of specific watershed/stream conditions. This highlights characteristics on which to focus future model development efforts. 相似文献
996.
Water, sanitation and hygiene (WaSH) are at the core of sustainable development. As we embark on a new round of global goals, namely the Sustainable Development Goals, a top priority is to address a coherent framework for monitoring these services. In the coming years, the sector will witness the development of a variety of multidimensional monitoring measures, albeit from different perspectives. This paper reviews the relevant literature and discusses the adequacy and applicability of one approach that is increasingly adopted for multidimensional poverty measurement at the household level, the Alkire‐Foster methodology. Drawing on this method, we identify and combine a set of direct household‐related water and sanitation deprivations that batter a person at the same time. This new multidimensional measure is useful for gaining a better understanding of the context in which WaSH services are delivered. It captures both the incidence and intensity of WaSH poverty, and provides a new tool to support monitoring and reporting. For illustrative purposes, one small town in Mozambique is selected as the initial case study. 相似文献
997.
中国湖泊水环境基准的研究进展 总被引:28,自引:9,他引:28
中国湖泊污染形势严峻、生态健康效应复杂,亟需适合中国区域特点的水环境基准作为加强污染控制、治理和管理的理论依据,但目前我国湖泊水环境基准的系统研究尚未开展,本文从水环境基准的意义、概念、研究历史、现状和发展趋势等几个方面对中国湖泊水环境基准研究进行了剖析回顾和展望:首先阐述了开展区域性水环境基准研究的迫切性和科学意义,揭示了"科学确定基准"的内涵;然后详细回顾了国内外湖泊水环境基准的研究历史、现状及存在的关键问题,提出了湖泊水环境基准的"三性"原则(科学性、基础性和区域性),指出环境暴露、效应识别和风险评估是基准研究的三个关键环节;最后提出中国湖泊水环境基准的研究方向和发展趋势,本文强调:阐明中国水环境的演变规律和特征,需要开展水环境污染过程和生态毒理效应研究;建立具有我国区域特点的湖泊水环境基准理论、技术和方法体系是面向国际科学前沿和解决中国环境管理重大科技需求的重要任务,它既可推动中国毒理学、生物学、生态学及环境与生物地球化学等学科的发展,又可为湖泊流域的环境管理和污染防治提供技术支撑,整体提升我国环境保护科学研究的水平和国际地位. 相似文献
998.
999.
介绍了动力风泵房每年有大量的工业余热为没经过处理直接排放,造成能源的浪费,以及其解决的思路:利用水源热泵吸收动力风泵房中产生的余热来加热水源,变成洗浴用水,从而达到节能减排的目的. 相似文献
1000.