全文获取类型
收费全文 | 299篇 |
免费 | 4篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 14篇 |
废物处理 | 23篇 |
环保管理 | 46篇 |
综合类 | 24篇 |
基础理论 | 76篇 |
污染及防治 | 90篇 |
评价与监测 | 18篇 |
社会与环境 | 11篇 |
灾害及防治 | 3篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 10篇 |
2016年 | 6篇 |
2015年 | 3篇 |
2014年 | 10篇 |
2013年 | 24篇 |
2012年 | 8篇 |
2011年 | 28篇 |
2010年 | 14篇 |
2009年 | 9篇 |
2008年 | 14篇 |
2007年 | 16篇 |
2006年 | 22篇 |
2005年 | 10篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 12篇 |
2001年 | 19篇 |
2000年 | 5篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 8篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 4篇 |
1975年 | 1篇 |
1958年 | 2篇 |
1954年 | 1篇 |
1948年 | 1篇 |
1933年 | 1篇 |
1928年 | 2篇 |
1927年 | 1篇 |
1924年 | 1篇 |
排序方式: 共有305条查询结果,搜索用时 31 毫秒
251.
252.
The present work was performed to investigate the use of odorant measurements for prediction of odor concentration in facilities with growing-finishing pigs and to analyze the odorant composition in facilities with different floor and ventilation systems. Air was sampled in Nalophan bags, odor concentrations were measured by dilution-to-threshold olfactometry, and concentrations of odorants were measured by proton-transfer-reaction mass spectrometry (PTR-MS). Olfactometry and chemical analyses were synchronized to take place at identical time intervals after sampling. A principal component analysis revealed that different facilities for growing-finishing pigs can be distinguished based on the odorants. Pit ventilation comprising a small amount of the total ventilation air (10-20%) in facilities with both room and pit ventilation can be used to concentrate odorants, whereas the room ventilation contains lower concentrations of most odorants. A partial least squares regression model demonstrated that prediction of the odor concentration based on odorants measured by PTR-MS is feasible. Hydrogen sulfide, methanethiol, trimethylamine, and 4-methylphenol were identified as the compounds having the largest influence on the prediction of odor concentration, whereas carboxylic acids had no significant influence. In conclusion, chemical measurement of odorants by PTR-MS is an alternative for expressing the odor concentration in facilities with growing-finishing pigs that can be used to increase the understanding of odor from different types of facilities and improve the development of odor reduction technologies. 相似文献
253.
254.
Mads Peter Heide-Jørgensen Louise M. Burt Rikke Guldborg Hansen Nynne Hjort Nielsen Marianne Rasmussen Sabrina Fossette Harry Stern 《Ambio》2013,42(5):596-610
The North Water polynya (~76°N to 79°N and 70°W to 80°W) is known to be an important habitat for several species of marine mammals and sea birds. For millennia, it has provided the basis for subsistence hunting and human presence in the northernmost part of Baffin Bay. The abundance of air-breathing top predators also represents a potential source of nutrient cycling that maintains primary production. In this study, aerial surveys conducted in 2009 and 2010 were used for the first time to map the distribution and estimate the abundance of top predators during spring in the North Water. Belugas (Delphinapterus leucas) were not detected north of 77°20′N but were found along the coast of West Greenland and offshore in the middle of the North Water with an abundance estimated at 2245 (95 % CI 1811–2783). Narwhals (Monodon monoceros) were widely distributed on the eastern side of the North Water with an estimate of abundance of 7726 (3761–15 870). Walruses (Odobenus rosmarus) were found across the North Water over both shallow and deep (>500 m) water with an estimated abundance of 1499 (1077–2087). Bearded (Erignathus barbatus) and ringed seals (Phoca hispida) used the large floes of ice in the southeastern part of the North Water for hauling out. Most polar bears (Ursus maritimus) were detected in the southern part of the polynya. The abundances of bearded and ringed seals were 6016 (3322–10 893) and 9529 (5460–16 632), respectively, and that of polar bears was 60 (12–292). Three sea bird species were distributed along the Greenland coast (eiders, Somateria spp.), in leads and cracks close to the Greenland coast (little auks, Alle alle) or widely in open water (thick-billed guillemots, Uria lomvia). 相似文献
255.
Kiley Daley Lisbeth Truelstrup Hansen Rob C. Jamieson Jenny L. Hayward Greg S. Piorkowski Wendy Krkosek Graham A. Gagnon Heather Castleden Kristen MacNeil Joanna Poltarowicz Emmalina Corriveau Amy Jackson Justine Lywood Yannan Huang 《Environmental science and pollution research international》2018,25(33):32926-32937
Drinking water in the vast Arctic Canadian territory of Nunavut is sourced from surface water lakes or rivers and transferred to man-made or natural reservoirs. The raw water is at a minimum treated by chlorination and distributed to customers either by trucks delivering to a water storage tank inside buildings or through a piped distribution system. The objective of this study was to characterize the chemical and microbial drinking water quality from source to tap in three hamlets (Coral Harbour, Pond Inlet and Pangnirtung—each has a population of <2000) on trucked service, and in Iqaluit (population ~6700), which uses a combination of trucked and piped water conveyance. Generally, the source and drinking water was of satisfactory microbial quality, containing Escherichia coli levels of <1 MPN/100 mL with a few exceptions, and selected pathogenic bacteria and parasites were below detection limits using quantitative polymerase chain reaction (qPCR) methods. Tap water in households receiving trucked water contained less than the recommended 0.2 mg/L of free chlorine, while piped drinking water in Iqaluit complied with Health Canada guidelines for residual chlorine (i.e. >0.2 mg/L free chlorine). Some buildings in the four communities contained manganese (Mn), copper (Cu), iron (Fe) and/or lead (Pb) concentrations above Health Canada guideline values for the aesthetic (Mn, Cu and Fe) and health (Pb) objectives. Corrosion of components of the drinking water distribution system (household storage tanks, premise plumbing) could be contributing to Pb, Cu and Fe levels, as the source water in three of the four communities had low alkalinity. The results point to the need for robust disinfection, which may include secondary disinfection or point-of-use disinfection, to prevent microbial risks in drinking water tanks in buildings and ultimately at the tap. 相似文献
256.
Importance of food quantity to structural growth rate and neutral lipid reserves accumulated in Calanus finmarchicus 总被引:1,自引:0,他引:1
Growth and developmental rates were determined for copepodids of Calanus finmarchicus (Gunnerus) from experimental seawater mesocosms in a western Norwegian fjord. The instantaneous growth rates (g) from copepodid stage I (CI) to adult ranged from 0.08 to 0.10 d−1. Daily per capita mortality rate of the cohorts was as low as 0.012 d−1 (1.2% d−1). At local increasing temperatures (5.1 to 8.3 °C), development was equiproportional, and the cumulative median development
time from egg to CV was approximately 65 d. CV moulted to males and females, and egg production was initiated. Enhancement
of food resources by nutrient addition caused a 23.4% increase in growth rates from CI to adult. Additionally, copepodid stages
showed a generally larger body size, carbon and nitrogen content and total storage lipid content (wax esters + triacylglycerols)
in response to enhanced resources. Our data support an elsewhere proposed exponential-growth hypothesis; growth of the structural
compartments and store lipids (mostly wax esters) was exponential during the copepodid stages. However, a sigmoidal pattern
of growth best described growth of adult stages if reared at high resources, and depot lipid accumulation in late CVs and
adults at high resources. Body nitrogen growth increased exponentially, however, no significant changes in nitrogen specific
growth rates were found between individuals from low and high resources. CV and adults seem to have reached near-maximal weights
at high resources, whereas structural weight continued to increase at low resources. Despite the differences in structural
growth dynamics, cohort development was similar until the end of CV. During the onset of sexual differentiation, the male:female
ratio and the adult:CV ratio were highest at high food resources, suggesting that the time used for the final moult depends
on the feeding history of the copepods in relation to food quality and quantity. It appears that relatively small changes
in food availability strongly influence the biochemical composition of C. finmarchicus copepodids.
Received: 28 May 1999 / Accepted: 10 February 2000 相似文献
257.
Janet A. Nestlerode Virginia D. Hansen Aarin Teague Matthew C. Harwell 《Environmental monitoring and assessment》2014,186(6):3477-3493
A multi-level coastal wetland assessment strategy was applied to wetlands in the northern Gulf of Mexico (GOM) to evaluate the feasibility of this approach for a broad national scale wetland condition assessment (US Environmental Protection Agency’s National Wetlands Condition Assessment). Landscape-scale assessment indicators (tier 1) were developed and applied at the sub-watershed (12-digit hydrologic unit code (HUC)) level within the GOM coastal wetland sample frame with scores calculated using land-use maps and geographic information system. Rapid assessment protocols (tier 2), using a combination of data analysis and field work, evaluated metrics associated with landscape context, hydrology, physical structure, and biological structure. Intensive site monitoring (tier 3) included measures of soil chemistry and composition, water column and pore-water chemistry, and dominant macrophyte community composition and tissue chemistry. Relationships within and among assessment levels were evaluated using multivariate analyses with few significant correlations found. More detailed measures of hydrology, soils, and macrophyte species composition from sites across a known condition gradient, in conjunction with validation of standardized rapid assessment method, may be necessary to fully characterize coastal wetlands across the region. 相似文献
258.
Olav R. Hansen Filippo Gavelli Mathieu Ichard Scott G. Davis 《Journal of Loss Prevention in the Process Industries》2010,23(6):857-877
The siting of facilities handling liquefied natural gas (LNG), whether for liquefaction, storage or regasification purposes, requires the hazards from potential releases to be evaluated. One of the consequences of an LNG release is the creation of a flammable vapor cloud, that may be pushed beyond the facility boundaries by the wind and thus present a hazard to the public. Therefore, numerical models are required to determine the footprint that may be covered by a flammable vapor cloud as a result of an LNG release. Several new models have been used in recent years for this type of simulations. This prompted the development of the “Model evaluation protocol for LNG vapor dispersion models” (MEP): a procedure aimed at evaluating quantitatively the ability of a model to accurately predict the dispersion of an LNG vapor cloud.This paper summarizes the MEP requirements and presents the results obtained from the application of the MEP to a computational fluid dynamics (CFD) model – FLACS. The entire set of 33 experiments included in the model validation database were simulated using FLACS. The simulation results are reported and compared with the experimental data. A set of statistical performance measures are calculated based on the FLACS simulation results and compared with the acceptability criteria established in the MEP. The results of the evaluation demonstrate that FLACS can be considered a suitable model to accurately simulate the dispersion of vapor from an LNG release. 相似文献
259.
Andersson KG Nielsen SP Thørring H Hansen HS Joensen HP Isaksson M Kostiainen E Suolanen V Pálsson SE 《Journal of environmental radioactivity》2011,102(11):1024-1031
The ECOSYS model is the ingestion dose model integrated in the ARGOS and RODOS decision support systems for nuclear emergency management. The parameters used in this model have however not been updated in recent years, where the level of knowledge on various environmental processes has increased considerably. A Nordic work group has carried out a series of evaluations of the general validity of current ECOSYS default parameters. This paper specifically discusses the parameter revisions required with respect to the modelling of deposition and natural weathering of contaminants on agricultural crops, to enable the trustworthy prognostic modelling that is essential to ensure justification and optimisation of countermeasure strategies. New modelling approaches are outlined, since it was found that current ECOSYS approaches for deposition and natural weathering could lead to large prognostic errors. 相似文献
260.
Firefighters are exposed to known health-damaging air pollutants present in bushfire smoke and poorly managed exposure can result in serious health issues. A better understanding of exposure levels and the major factors influencing exposures is crucial for the development of mitigation strategies to minimise exposure risks and adverse health impacts. This study monitored air toxics within the breathing zone of firefighters at prescribed burns and at wildfires in Australia. The results showed that exposure levels were highly variable, with higher exposures (sometimes exceeding occupational exposure standards) associated with particular work tasks (such as patrol and suppression) and with certain burn conditions. The majority of firefighter's exposures were at low and moderate levels (~60%), however considerable attention should be given to the high (~30%) and very high (6%) exposure risk situations for which acute and chronic health risks are very likely and for which control strategies should be developed and implemented to minimise health risks. 相似文献