全文获取类型
收费全文 | 275篇 |
免费 | 2篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 6篇 |
废物处理 | 11篇 |
环保管理 | 51篇 |
综合类 | 39篇 |
基础理论 | 71篇 |
污染及防治 | 79篇 |
评价与监测 | 15篇 |
社会与环境 | 6篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 29篇 |
2012年 | 10篇 |
2011年 | 16篇 |
2010年 | 7篇 |
2009年 | 12篇 |
2008年 | 25篇 |
2007年 | 20篇 |
2006年 | 19篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 16篇 |
2002年 | 10篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1971年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有284条查询结果,搜索用时 31 毫秒
51.
Chemical fingerprinting techniques recently have been used to track larval dispersal of estuarine species that bear calcified
structures, but the applicability of this important approach may be limited on the open coast where chemical signatures may
be less distinctive and for the many species that do not retain calcified structures throughout development. Externally brooded
embryos of the porcelain crab, Petrolisthes cinctipes, and inductively coupled plasma mass spectrometry were used to determine whether fine-scale variation in trace-elemental
composition occurred along an open coast. Embryos were collected from 16 sites from 37.8° to 39.5° north latitude along the
Pacific Coast of California, USA during late January and early February 2003. Discriminant function analysis revealed that
collection sites, many separated by only a few kilometers along an open coast, could be differentiated with an overall accuracy
of 73%, and combining the sites into three regions increased the accuracy to 88%. Thus, distinctive elemental signatures can
be detected in open coast species even at a fine scale raising the possibility that larval tags can be developed for many
more species than previously thought possible. 相似文献
52.
Deurer M Sivakumaran S Ralle S Vogeler I McIvor I Clothier B Green S Bachmann J 《Journal of environmental quality》2008,37(3):915-924
A new method to diagnose the environmental sustainability of specific orchard management practices was derived and tested. As a significant factor for soil quality, the soil carbon (C) management in the topsoil of the tree-row of an integrated and organic apple orchard was selected and compared. Soil C management was defined as land management practices that maintain or increase soil C. We analyzed the impact of the soil C management on biological (microbial biomass C, basal respiration, dehydrogenase activity, respiratory quotient) and physical (aggregate stability, amount of plant-available water, conductive mean pore diameter near water saturation) soil properties. Soil in the alley acted as a reference for the managed soil in the tree row. The total and hot-water-extractable C amounts served as a combined proxy for the soil C management. The soil C management accounted for 0 to 81% of the degradation or enhancement of biophysical soil properties in the integrated and organic system. In the integrated system, soil C management led to a loss of C in the top 0.3 m of the tree row within 12 yr, causing a decrease in microbial activities. In the tree row of the organic orchard, C loss occurred in the top 0.1 m, and the decrease in microbial activities was small or not significant. Regarding physical soil properties, the C loss in the integrated system led to a decrease of the aggregate stability, whereas it increased in the organic system. Generally, the impact of soil C management was better correlated with soil microbial than with the physical properties. With respect to environmental soil functions that are sensitive to the decrease in microbial activity or aggregate stability, soil C management was sustainable in the organic system but not in the integrated system. 相似文献
53.
Response of balanced network models to large-scale perturbation: Implications for evaluating the role of small pelagics in the Gulf of Maine 总被引:1,自引:0,他引:1
Jason Link Laurel Col Vincent Guida David Dow John O’Reilly Jack Green William Overholtz Debra Palka Chris Legault Joseph Vitaliano Carolyn Griswold Michael Fogarty Kevin Friedland 《Ecological modelling》2009
Exploring the response of an ecosystem, and subsequent tradeoffs among its biological community, to human perturbations remains a key challenge for the implementation of an ecosystem approaches to fisheries (EAF). To address this and related issues, we developed two network (or energy budget) models, Ecopath and Econetwrk, for the Gulf of Maine ecosystem. These models included 31 network “nodes” or biomass state variables across a broad range of trophic levels, with the present emphasis to particularly elucidate the role of small pelagics. After initial network balancing, various perturbation scenarios were evaluated to explore how potential changes to different fish, fisheries and lower trophic levels can affect model outputs. Categorically across all scenarios and interpretations thereof, there was minimal change at the second trophic levels and most of the “rebalancing” after a perturbation occurred via alteration of the diet matrix. Yet the model results from perturbations to a balanced energy budget fall into one of three categories. First, some model results were intuitive and in obvious agreement with established ecological and fishing theory. Second, some model results were counter-intuitive upon initial observation, seemingly contradictory to known ecological and fishing theory; but upon further examination the results were explainable given the constraints of an equilibrium energy budget. Finally, some results were counter-intuitive and difficult to reconcile with theory or further examination of equilibrium constraints. A detailed accounting of biomass flows for example scenarios explores some of the non-intuitive results more rigorously. Collectively these results imply a need to carefully track biomass flows and results of any given perturbation and to critically evaluate the conditions under which a new equilibrium is obtained for these types of models, which has implications for dynamic simulations based off of them. Given these caveats, the role of small pelagics as a prominent component of this ecosystem remains a robust conclusion. We discuss how one might use this approach in the context of further developing an EAF, recognizing that a more holistic, integrated perspective will be required as we continue to evaluate tradeoffs among marine biological communities. 相似文献
54.
Thomas J. Kulle Larry R. Sauder J. Richard Hebel Donald J. Green Marie D. Chatham 《Journal of the Air & Waste Management Association (1995)》2013,63(8):919-924
Industrial, commercial, and domestic levels of formaldehyde exposure range from <0.1 to >5.0 ppm. Irritation of the eyes and upper respiratory tract predominate, and bronchoconstriction is described in case reports. However, pulmonary function and irritant symptoms together have not been assessed over a range of HCHO concentrations in a controlled environment. We investigated dose response in both symptoms and pulmonary function associated with 3-h exposures to 0.0-3.0 ppm HCHO in a controlled environmental chamber. Ten subjects were randomly exposed to 0.0, 0.5, 1.0, and 2.0 ppm HCHO at rest plus 2.0 ppm HCHO with exercise and nine additional subjects were randomly exposed to 0.0,1.0,2.0, and 3.0 ppm HCHO at rest plus 2.0 ppm HCHO with exercise. Significant dose-response relationships in odor and eye irritation were observed (p < 0.05). Nasal flow resistance was increased at 3.0 ppm (p < 0.01), but not at 2.0 ppm HCHO. There were no significant decrements in pulmonary function (FVC, FEV1, FEF25-75%, SGaw) or increases in bronchial reactivity to methacholine (log PD35SGaw) with exposure to 0.5-3.0 ppm HCHO at rest or to 2.0 ppm HCHO with exercise. 相似文献
55.
国合会“绿色转型与可持续社会治理专题政策研究”课题组 《中国环境管理》2020,12(1):24-30
当前,中国经济正在从高速增长转向高质量发展,其中消费是拉动经济增长的主要动力,是推动高质量发展的重要动能。从中国整体绿色发展转型进程和状态看,不平衡不协调的问题比较突出,经济维度的绿色转型发展较快较好,社会维度相对滞后。因此,如何在社会生活和消费领域推动绿色转型是中国政府应关注和解决的重大关键问题。国合会2018年主题是“创新引领绿色新时代”,本项目作为“创新与可持续生产和消费”课题下的专题研究,将为国家生态文明建设战略部署下如何推动形成绿色生活方式和消费方式以及提升社会治理体系提供政策决策支持。 相似文献
56.
C.D. Green 《Agriculture, ecosystems & environment》1985,13(2):175
57.
Coral reef habitat mapping: how much detail can remote sensing provide? 总被引:12,自引:0,他引:12
The capability of satellite and airborne remote-sensing methods for mapping Caribbean coral reefs is evaluated. Reef habitats
were categorised into coarse, intermediate and fine detail, using hierarchical classification of field data (percent cover
in 1 m quadrats and seagrass standing-crop). Habitats were defined as assemblages of benthic macro-organisms and substrata
and were mapped using the satellite sensors Landsat MSS, Landsat TM, SPOT XS, SPOT Pan and merged Landsat TM/SPOT Pan. Habitats
were also mapped using the high-resolution digital airborne sensor, CASI (compact airborne spectrographic imager). To map
areas >60 km in any direction with coarse detail, Landsat TM was the most accurate and cost-effective satellite sensor (SPOT
XS when <60 km). For maps with intermediate habitat detail, aerial photography (from a comparable study in Anguilla) exhibited
similar accuracy to Landsat TM, SPOT XS, SPOT Pan and merged Landsat TM/SPOT Pan. Landsat MSS was consistently the least accurate
sensor. Maps from CASI were significantly (p<0.001) more accurate than satellite sensors and aerial photographs. Maps with detailed habitat information (i.e. >9 reef
classes) had a maximum accuracy of 37% when based on satellite imagery, but aerial photography and CASI achieved accuracies
of 67 and 81%, respectively. Commissioning of new aerial photography does not appear to be a cost-effective option; satellites
are cheaper for coarse habitat-mapping, and detailed habitat-mapping can be conducted more accurately and cheaply with CASI.
The results will guide practitioners in matching survey objectives to appropriate remote-sensing methods.
Received: 11 July 1997 / Accepted: 6 August 1997 相似文献
58.
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
59.
Previous studies of upland roadside soils in Cumbria, that would normally be naturally acidic, have highlighted that (a) runoff from roads subjected to long-term road salting can dramatically raise soil pH down slope in upland areas; (b) the soil pH increase dramatically changes N cycling in soils down slope, increasing mineralisation of organic matter, ammonification, ammonium leaching down slope and nitrification and nitrate leaching; (c) the increase in nitrification substantially increases nitrate leaching to down-slope rivers, and this is readily detectable in field studies; and (d) loss of soil organic matter over decades of salting is so great that organic matter is no longer substantially solubilised by high salt concentrations found in soil solution below road drains. This paper tests and supports the hypothesis that such effects are minimal for more calcareous soil ecosystems. It examines the soil and soil solution chemistry on another Cumbrian upland highway, the A686 near Leadgate, Alston. Sodium % of soil CEC values for soil transects affected by spray containing road salt are similar at both the A6 and A686 sites. However, spatial trends in calcium, magnesium, ammonium, and nitrate concentrations as well as pH differ, as a direct result of the higher weathering rate of parent material and possibly also the presence of limestone walls above both spray-affected and control transects at the A686 site. 相似文献
60.
Cátia Canteiro Laísa Barcelos Fabiana Filardi Rafaela Forzza Laura Green João Lanna Paula Leitman William Milliken Marli Pires Morim Kristina Patmore Sarah Phillips Barnaby Walker Marie-Hélène Weech Eimear Nic Lughadha 《Conservation biology》2019,33(3):523-533
Herbarium specimens are increasingly recognized as an important resource for conservation science and virtual herbaria are making specimens freely available to a wider range of users than ever before. Few virtual herbaria are designed with conservation use as a primary driver. Exceptionally, Brazil's Reflora Virtual Herbarium (RVH) was created to increase knowledge and conservation of the Brazilian flora. The RVH is closely integrated with the Flora of Brazil 2020 platform on which Brazil's new national Flora is under construction. Both resources are accessible via the Reflora home page and thousands of users move seamlessly between these Reflora resources. To understand how the Reflora resources are currently used and their impact on conservation science, we conducted a literature review and an online survey. We searched for publications of studies in which Reflora resources were used and publications resulting from Brazilian researchers who were part of Reflora's research and mobility program. The survey contained multiple choice questions and questions that required a written response. We targeted Reflora webpage visitors with the survey to capture a wider range of Reflora users than the literature review. Reflora resources were used for a variety of conservation-relevant purposes. Half the 806 scientific publications in which Reflora was cited and 81% of the 1069 survey respondents accessing Reflora resources mentioned conservation-relevant research outputs. Most conservation-relevant uses of the Reflora resources in scientific publications were research rather than implementation focused. The survey of Reflora users showed conservation uses and impacts of virtual herbaria were more numerous and diverse than the uses captured in the literature review. Virtual herbaria are vital resources for conservation science, but they must document use and impacts more comprehensively to ensure sustainability. 相似文献