全文获取类型
收费全文 | 637篇 |
免费 | 8篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 22篇 |
废物处理 | 18篇 |
环保管理 | 87篇 |
综合类 | 98篇 |
基础理论 | 138篇 |
环境理论 | 2篇 |
污染及防治 | 196篇 |
评价与监测 | 39篇 |
社会与环境 | 46篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 13篇 |
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 21篇 |
2017年 | 18篇 |
2016年 | 19篇 |
2015年 | 29篇 |
2014年 | 28篇 |
2013年 | 47篇 |
2012年 | 29篇 |
2011年 | 38篇 |
2010年 | 43篇 |
2009年 | 40篇 |
2008年 | 30篇 |
2007年 | 39篇 |
2006年 | 31篇 |
2005年 | 20篇 |
2004年 | 29篇 |
2003年 | 21篇 |
2002年 | 27篇 |
2001年 | 10篇 |
2000年 | 16篇 |
1999年 | 16篇 |
1998年 | 6篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1984年 | 2篇 |
1980年 | 3篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1963年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1958年 | 1篇 |
1955年 | 1篇 |
1949年 | 1篇 |
1948年 | 1篇 |
1937年 | 1篇 |
1920年 | 1篇 |
排序方式: 共有652条查询结果,搜索用时 0 毫秒
51.
Stefan E. Salbach R. Peter Dennis 《Journal of the American Water Resources Association》1980,16(4):621-626
ABSTRACT: The Ontario Ministry of the Environment has based its water quality management approach on a set of guidelines published in 1970. In light of the changing societal and economic background, advancement in technology and scientific knowledge, and philosophical attitudes towards water management, the water management program was recently revised. Factors influencing the revised approach, including federal-provincial interrelationships and international commitments under the Canada-U.S. Agreement, are summarized. The revised program consists of a goal statement, policies to implement this goal, revised water quality objectives, and detailed implementation procedures for field staff use. Rather than promulgating regulations to impose arbitrary effluent or receiving water standards on a province-wide basis, the revised approach involves the imposition of legally enforceable effluent requirements on a case-by-case basis. Although the paper emphasizes the surface water quality program, it also outlines the Ministry's goals, policies, and procedures for the management of surface-water quantity, as well as ground water quality and quantity. 相似文献
52.
Model simulations of dissolved oxygen characteristics of Minnesota lakes: Past and future 总被引:1,自引:0,他引:1
A deterministic, one-dimensional, unsteady numerical model has been developed, tested, and applied to simulate mean daily
dissolved oxygen (DO) characteristics in 27 lake classes in the state of Minnesota. Reaeration and photosynthesis are the
oxygen sources, while respiration, sedimentary, and biochemical water column oxygen demand are the sinks of oxygen in the
model. The lake classes are differentiated by surface area (A
s), maximum depth (H
max), and trophic status expressed as Secchi depth (Z
s). Because lake stratification is most important to lake oxygen dynamics, simulated DO characteristics are plotted in terms
of a stratification parameterA
s/H
max
0.25
and Secchi depthZ
s. Simulations provide DO profiles on a daily time scale. Specific DO characteristics of ecological and environmental interest
are epilimnetic DO, hypolimnetic DO, DO gradient from surface to bottom, and DO minima and maxima. Specific results are as
follows: Simulated mean daily and weekly DO values in the epilimnion of all lakes for both past and future climate scenarios
are near saturation over the summer season. Hypolimnetic DO values depend strongly on lake morphometry, trophic status, and
time throughout the summer season. Future climate conditions are specified as the historical records from 1955 to 1979, adjusted
(monthly) by the 2 × CO2 GISS model output to account for doubling of atmospheric CO2. With this climate change, weekly averaged epilimnetic DO is projected to drop by less than 2 mg/liter, and will remain above
7 mg/liter throughout the open water season. The hypolimnetic DO reductions after climate change are on the order of 2–8 mg/liter.
Periods of anoxia are longer by as much as 80 days. Those changes would alter water quality dynamics in lakes and have a profound
effect on lake ecosystems including indigenous fishes. The results presented are useful for evaluating environmental management
options. 相似文献
53.
John B. Erdmann Heinz G. Stefan Patrick L. Brezonik 《Journal of the American Water Resources Association》1994,30(6):1043-1053
ABSTRACT: Suspended solids and ammonium concentration profiles measured at five locations in Duluth-Superior Harbor during July-October 1985 were analyzed to quantify wind and ship effects on sediment resuspension and resulting harbor water quality. Wind components from the SE quadrant correlated strongly with depth-averaged suspended solids concentrations that were unaffected by ship passage or thermal stratification. Winds from that quadrant have the largest fetch in the harbor. The highest correlation (r2= 0.93) was with the 6-hour average of the ESE wind velocity component. Multiple linear regression analysis of data from post-ship passage concentration profiles yielded numerical estimates of settling velocities of 0.08 to 0.25 cm s?1, typical of ship-resuspended sediments, and vertical eddy diffusivities of 4 to 13 cm2 s1. The results suggest that ambient vertical eddy diffusivities in the harbor are less than 4 cm2 s?1 in the absence of ship passages and with winds less than 5 m s?1 (10 knots). 相似文献
54.
Stefan Linde 《环境政策》2018,27(2):228-246
By creating attitudinal rifts among partisan voters, political polarization is expected to negatively affect chances of effectively mitigating climate change. While such expectations generally have found support, less attention has been paid to the opposite claim that political consensus should eliminate the partisan dimension in climate change politics. This study tests this claim by studying how party identification, and party cues specifically, affects public policy attitudes in a context defined by political consensus. Using data from a large online access panel in Sweden, party identification and party cues are shown to matter for policy attitudes even in a consensus context. This effect is not limited to certain issues but is found across a wide range of policies, and the effect of party cues, for a given issue, varies across parties. The implications of this study and areas for future work are discussed. 相似文献
55.
Charlotte N. Legind Stefan Trapp 《Environmental pollution (Barking, Essex : 1987)》2009,157(3):778-785
Exposure to chemicals via diet is a major uptake pathway for many compounds but is often estimated in a rather generic way. We use a new model framework (NMF) with crop-specific models to predict the dietary intake by 4-5-year-old children and 14-75-year-old women of three environmental compounds from their background concentrations in soil and air. Calculated daily intakes of benzo(a)pyrene and 2,3,7,8-TCDD are in good agreement with measured results from diet studies. The major source of both compounds in human diet is deposition from air. Inhalation of air and ingestion of soil play a minor role. Children take up more than twice the amount than adults per kg bodyweight, due to higher consumption per kg bodyweight. Contrary, the methods for indirect human exposure suggested in the Technical Guidance Document (TGD) for chemical risk assessment in the EU lead to overprediction, due to unrealistic consumption data and a false root model. 相似文献
56.
Jenny Bergqvist Stefan Gunnarsson 《Journal of Agricultural and Environmental Ethics》2013,26(1):75-99
The aim of this review is to assess the ethical implications of finfish aquaculture, regarding fish welfare and environmental aspects. The finfish aquaculture industry has grown substantially the last decades, both as a result of the over-fishing of wild fish populations, and because of the increasing consumer demand for fish meat. As the industry is growing, a significant amount of research on the subject is being conducted, monitoring the effects of aquaculture on the environment and on animal welfare. The areas of concern when it comes to animal welfare have here been divided into four different stages: breeding period; growth period; capturing and handling; and slaughter. Besides these stages, this report includes a chapter on the current evidence of fish sentience, since this issue is still being debated among biologists. However, most biologists are at present acknowledging the probability of fish being sentient creatures. Current aquaculture practices are affecting fish welfare during all four of the cited stages, both on physical and mental levels, as well as on the ability of fish to carry out natural behaviors. The effect fish farming has on the environment is here separated into five different categories: the decline of wild fish populations; waste and chemical discharge; loss of habitat; spreading of diseases; and invasion of exotic organisms. There is evidence of severe negative effects on the environment when looking at these five categories, even when considering the difficulty of studying environmental effects, due to the closely interacting variables. The ethical arguments and scientific evidences here reviewed have not all come to the same conclusions. Nevertheless, the general agreement is that current aquaculture practices are neither meeting the needs of fish nor environment. Thus, the obvious environmental and animal welfare aspects of finfish aquaculture make it hard to ethically defend a fish diet. 相似文献
57.
Stakeholders on Meat Production, Meat Consumption and Mitigation of Climate Change: Sweden as a Case
Henrik Lerner Bo Algers Stefan Gunnarsson Anders Nordgren 《Journal of Agricultural and Environmental Ethics》2013,26(3):663-678
In this paper we analyse and discuss the views of Swedish stakeholders on how to mitigate climate change to the extent it is caused by meat production. The stakeholders include meat producer organisations, governmental agencies with direct influence on meat production, political parties as well as non-governmental organisations. Representatives of twelve organisations were interviewed. Several organisations argued against the mitigation option of reducing beef production despite the higher greenhouse gas intensity of beef compared to pork and chicken meat (according to life cycle analysis). Regarding feed production some organisations proposed use of the best available industrial fertilizers, others were against all use of such fertilizers. Several organizations suggested domestic production of more protein-rich fodder and use of manure for biogas production. Regarding meat consumption the focus was on throwing away less food as waste and on eating less meat but the best (most climate friendly) meat, which was considered to be Swedish meat in contrast to imported meat. There was agreement on many issues. Most disagreement was found regarding political steering. We find many of the stakeholders’ mitigation proposals regarding meat production and consumption acceptable. However, we are to some extent critical to their defence of Swedish beef production. We also point out certain problems with the suggestion to reduce consumption of imported meat but not of domestically produced meat. 相似文献
58.
Stefan Bachu Mehran Pooladi-Darvish Huifang Hong 《International Journal of Greenhouse Gas Control》2009,3(4):468-473
Laboratory experiments reported in a companion paper were carried out to examine the chromatographic partitioning of impurities contained in a stream of CO2 injected into a deep saline aquifer. The solubility of the impurity gas in the CO2 stream compared to that of CO2, the in situ conditions of pressure, temperature and water salinity, and the concentration of the impurity gas affect the partitioning of the two gases. For CO2 streams containing H2S, numerical simulations reported here have successfully replicated the laboratory results including the breakthrough of CO2 ahead of H2S. Sensitivity analysis performed with the numerical model has shown that flow conditions, controlled by such parameters as medium permeability, pressure gradient, dispersion, gas mobility and flow direction, affect the breakthrough time and separation of the two gases, leading to delayed or earlier breakthrough, and increasing or decreasing the time lag between the breakthrough of the two gases. Vertical bottom-up flow leads to earlier breakthrough, while top-down flow leads to delayed breakthrough. These results are important in establishing monitoring strategies at CO2 storage sites and in evaluating the risks associated with the possible leakage of injected CO2 that contains impurities. 相似文献
59.
Algae blooms, which can be caused by eutrophication, drastically influence the ecology and behaviour of aquatic organisms. Such impact is often demonstrated in the context of mate choice and predator–prey interactions. In contrast, the influence of increased turbidity on social behaviour is less well understood, although it may have strong influence, at both the level of the individual and the population. We aimed to address this gap in our knowledge by using the well-described preference of three-spined sticklebacks (Gasterosteus aculeatus) to shoal with the larger of two shoals as model behaviour. In our experiments focal fish had the choice between two shoals of different sizes, either in clear or in turbid water containing green algae. Fish in clear water spent significantly more time near the larger shoal, while fish in algae water showed no significant preferences. Furthermore, fish tested in clear water changed more often between the shoals than fish tested in algae water. These results indicate that eutrophication-induced algae blooms have the potential to alter social decisions of sticklebacks. Such changes of social decisions do not only influence the behaviour of individuals, furthermore it might influence entire populations. This might eventually lead to changes of the structure of the social system. 相似文献
60.
Stefan Leichsenring Dieter Lenoir Antonius Kettrup Gerd Mützenich 《Environmental Sciences Europe》1996,8(4):197-206
The 17th BlmSchV fixed the emission limit of 0.1 ng TE/mn 3 for PCDD/F’s produced as a result of waste- and special waste incinerators. This article introduces the different measures implemented to uphold this limit, and discusses their advantages and disadvantages. Methods of optimising the incineration conditions are among the primary measures. Different geometry’s for conventional oven incineration rooms were discussed, and an effective modernisation method was introduced (Temelli nozzles). The chemical and technical basis of an often discussed gasification method, as well as the characteristics of three specialised techniques (Coke Burn technique, Thermo-Select technique and Noell-DBI technique) are explained in this article. Alongside the secondary measures of hot-dust filtration and inhibition being added to the washers in an attempt to achieve PCDD/F adsorption. The most important tertiary measures, namely the SCR technique, along with a variety of coke adsorption techniques are introduced, with their advantages and disadvantages. New techniques such as DeDioxin and Medisorbon are also addressed. 相似文献