全文获取类型
收费全文 | 4328篇 |
免费 | 26篇 |
国内免费 | 58篇 |
专业分类
安全科学 | 100篇 |
废物处理 | 150篇 |
环保管理 | 521篇 |
综合类 | 1022篇 |
基础理论 | 948篇 |
环境理论 | 3篇 |
污染及防治 | 960篇 |
评价与监测 | 325篇 |
社会与环境 | 372篇 |
灾害及防治 | 11篇 |
出版年
2022年 | 37篇 |
2021年 | 69篇 |
2020年 | 33篇 |
2019年 | 38篇 |
2018年 | 71篇 |
2017年 | 62篇 |
2016年 | 107篇 |
2015年 | 61篇 |
2014年 | 127篇 |
2013年 | 343篇 |
2012年 | 129篇 |
2011年 | 196篇 |
2010年 | 135篇 |
2009年 | 183篇 |
2008年 | 169篇 |
2007年 | 193篇 |
2006年 | 151篇 |
2005年 | 130篇 |
2004年 | 135篇 |
2003年 | 151篇 |
2002年 | 127篇 |
2001年 | 143篇 |
2000年 | 98篇 |
1999年 | 64篇 |
1998年 | 35篇 |
1997年 | 43篇 |
1996年 | 27篇 |
1995年 | 59篇 |
1994年 | 35篇 |
1993年 | 38篇 |
1992年 | 39篇 |
1991年 | 40篇 |
1990年 | 50篇 |
1989年 | 43篇 |
1988年 | 30篇 |
1987年 | 31篇 |
1986年 | 25篇 |
1985年 | 31篇 |
1984年 | 26篇 |
1983年 | 38篇 |
1982年 | 27篇 |
1981年 | 42篇 |
1980年 | 30篇 |
1979年 | 30篇 |
1977年 | 27篇 |
1976年 | 28篇 |
1975年 | 25篇 |
1972年 | 23篇 |
1970年 | 23篇 |
1965年 | 23篇 |
排序方式: 共有4412条查询结果,搜索用时 359 毫秒
871.
Salami Babatunde Abiodun Oyehan Tajudeen Adeyinka Gambo Yahya Badmus Suaibu O. Tanimu Gazali Adamu Sagir Lateef Saheed A. Saleh Tawfik A. 《Environmental science and pollution research international》2022,29(28):42560-42600
Environmental Science and Pollution Research - Water and wastewater treatment applications stand to benefit immensely from the design and development of new materials based on silica nanoparticles... 相似文献
872.
Georgin Jordana Netto Matias S. Franco Dison S. P. Piccilli Daniel G. A. da Boit Martinello Kátia Silva Luis F. O. Foletto Edson L. Dotto Guilherme L. 《Environmental science and pollution research international》2022,29(12):16988-17000
Environmental Science and Pollution Research - Activated carbon prepared from grape branches was used as a remarkable adsorbent to uptake naproxen and treat a synthetic mixture from aqueous... 相似文献
873.
Given recent focus on large rivers as conduits for excess nutrients to coastal zones, their role in processing and retaining nutrients has been overlooked and understudied. Empirical measurements of nutrient uptake in large rivers are lacking, despite a substantial body of knowledge on nutrient transport and removal in smaller streams. Researchers interested in nutrient transport by rivers (discharge >10000 L/s) are left to extrapolate riverine nutrient demand using a modeling framework or a mass balance approach. To begin to fill this knowledge gap, we present data using a pulse method to measure inorganic nitrogen. (N) transport and removal in the Upper Snake River, Wyoming, USA (seventh order, discharge 12000 L/s). We found that the Upper Snake had surprisingly high biotic demand relative to smaller streams in the same river network for both ammonium (NH4+) and nitrate (NO3-). Placed in the context of a meta-analysis of previously published nutrient uptake studies, these data suggest that large rivers may have similar biotic demand for N as smaller tributaries. We also found that demand for different forms of inorganic N (NH4+ vs. NO3-) scaled differently with stream size. Data from rivers like the Upper Snake and larger are essential for effective water quality management at the scale of river networks. Empirical measurements of solute dynamics in large rivers are needed to understand the role of whole river networks (as opposed to stream reaches) in patterns of nutrient export at regional and continental scales. 相似文献
874.
Algal carbon has been increasingly recognized as the primary carbon source supporting large-river food webs; however, many of the studies that support this contention have focused on lotic main channels during low-flow periods. The flow variability and habitat-heterogeneity characteristic of these systems has the potential to significantly influence food web structure and must be integrated into models of large-river webs. We used stable-isotope analysis and IsoSource software to model terrestrial and algal sources of organic carbon supporting consumer taxa in the main channel and oxbow lakes of the Brazos River, Texas, USA, during a period of frequent hydrologic connectivity between these habitat types. Standardized sampling was conducted monthly to collect production sources and consumer species used in isotopic analysis. Predictability of hydrologic connections between habitat types was based on the previous 30 years of flow data. IsoSource mixing models identified terrestrial C3 macrophytes (riparian origin) as the primary carbon source supporting virtually all consumers in the main channel and most consumers in oxbow lakes. Small-bodied consumers (<100 mm) in oxbow lakes assimilated large fractions of algal carbon whereas this pattern was not apparent in the main channel. Estimates of detritivore trophic positions based on delta15N values indicated that terrestrial material was likely assimilated via invertebrates rather than directly from detritus. High flows in the river channel influenced algal standing stock, and differences in the importance of terrestrial and algal production sources among consumers in channel vs. oxbow habitats were associated with patterns of flooding. The importance of terrestrial material contradicts the findings of recent studies of large-river food webs that have emphasized the importance of algal carbon and indicates that there can be significant spatial, temporal, and taxonomic variation in carbon sources supporting consumers in large rivers. 相似文献
875.
Inac S Gorucu O Pinar AH 《Journal of environmental biology / Academy of Environmental Biology, India》2008,29(3):411-414
Kumasir lake is located next to towns of Donuklu and Fatih, nine km west of Kahramanmaras city center the region of east Mediterranean, Turkey This lake is of crucial importance from the point of native and immigrant birds. We located 17 birdspecies in this area during our observations carried out in the spring and autumn of 2005-2006. These were Ciconia ciconia L., Anas platyrhynchos L., Accipiter nisus L., Accipiter brevipes L., Fulica atra L., Columba palumbus L., Merops apiaster L., Upupa epops L., Alauda arvensis L., Motacilla flava L., Turdus merula L., Acrocephalus scirpaceus L., Regulus regulus L., Garrulus glandarius L., Corvus corax L., Fringilla coelebs L., Hirundo rustica L.. Among observed 17 species; 6 of them were immigrant and remaining 11 of them were native birds. Kumasir lake is surrounded by wetland of Amik and Gavur lake. Since it was greatly dried, it was transformed to farmland. Consequently the birds lost most of theirnests and settlements. However not taken in the care of environmental ethic values, the wastewaters of the villages drain to lake reservoir; herbicides and insecticides used for agriculture are polluting the water reeds have been burned, the lake's reeds are getting dry by the irrigation for the farmland. So, the wetland ecosystem is being affected negatively by these factors. On the other hand, the birds are exposed to illegal and unlawful hunting. For this reasons, this lake must be taken into a management regime of sustainable wetland (protection profiting balance) and used techniques of participation planning via the process of sustainable natural resources and planning. 相似文献
876.
Elva J. H. Robinson Thomas O. Richardson Ana B. Sendova-Franks Ofer Feinerman Nigel R. Franks 《Behavioral ecology and sociobiology》2009,63(5):779-636
Ant colonies are factories within fortresses (Oster and Wilson 1978). They run on resources foraged from an outside world fraught with danger. On what basis do individual ants decide to leave the safety of the nest? We investigated the relative roles of social information (returning nestmates), individual experience and physiology (lipid stores/corpulence) in predicting which ants leave the nest and when. We monitored Temnothorax albipennis workers individually using passive radio-frequency identification technology, a novel procedure as applied to ants. This method allowed the matching of individual corpulence measurements to activity patterns of large numbers of individuals over several days. Social information and physiology are both good predictors of when an ant leaves the nest. Positive feedback from social information causes bouts of activity at the colony level. When certain social information is removed from the system by preventing ants returning, physiology best predicts which ants leave the nest and when. Individual experience is strongly related to physiology. A small number of lean individuals are responsible for most external trips. An individual’s nutrient status could be a useful cue in division of labour, especially when public information from other ants is unavailable. 相似文献
877.
B. Mike Wotton 《Environmental and Ecological Statistics》2009,16(2):107-131
Understanding and being able to predict forest fire occurrence, fire growth and fire intensity are important aspects of forest
fire management. In Canada fire management agencies use the Canadian Forest Fire Danger Rating System (CFFDRS) to help predict
these elements of forest fire activity. In this paper a review of the CFFDRS is presented with the main focus on understanding
and interpreting Canadian Fire Weather Index (FWI) System outputs. The need to interpret the outputs of the FWI System with
consideration to regional differences is emphasized and examples are shown of how the relationship between actual fuel moisture
and the FWI System’s moisture codes vary from region to region. Examples are then shown of the relationship between fuel moisture
and fire occurrence for both human- and lightning-caused fire for regions with different forest composition. The relationship
between rate of spread, fuel consumption and the relative fire behaviour indices of the FWI System for different forest types
is also discussed. The outputs of the CFFDRS are used every day across Canada by fire managers in every district, regional
and provincial fire management office. The purpose of this review is to provide modellers with an understanding of this system
and how its outputs can be interpreted. It is hoped that this review will expose statistical modellers and other researchers
to some of the models used currently in forest fire management and encourage further research and development of models useful
for understanding and managing forest fire activity.
相似文献
B. Mike WottonEmail: |
878.
Ocean acidification (OA) and the biological consequences of altered seawater chemistry have emerged as a significant environmental
threat to healthy marine ecosystems. Because a more acidic ocean interferes with fixation of calcium carbonate to form shells
or calcified skeletons, future ocean chemistry may significantly alter the physiology of calcifying marine organisms. These
alterations may manifest themselves directly in the calcification process, or have synergistic effects with other environmental
factors such as elevated temperatures. New tools permit us to explore subtle changes in gene expression patterns in response
to environmental conditions. We raised sea urchins (Strongylocentrotus franciscanus) under conditions simulating future atmospheric CO2 levels of 540 and 970 ppm. When larvae raised under elevated CO2 conditions were subjected to 1-h acute temperature stress, their ability to mount a physiological response (as measured by
expression of the molecular chaperone hsp70) was reduced relative to those raised under ambient CO2 conditions. These results represent the first use of gene expression assays to study the effects of OA on sea urchin development.
They highlight the importance of looking at multiple environmental factors simultaneously as this approach may reveal previously
unsuspected biological impacts of atmospheric changes. 相似文献
879.
Herbivory has a strong impact on algal distribution, abundance and community structure and may influence the establishment
and spread of introduced seaweed species. In this study, we assess the potential regulating role of herbivory on one of the
most invasive brown seaweeds: Sargassum muticum. Multiple choice feeding experiments were conducted with 13 native seaweeds, S. muticum and 5 herbivore species from the Northwest, Southwest and South of Portugal. S. muticum was always the least or among the least preferred seaweeds and attained one of the highest growth rates of the tested seaweeds,
with and without herbivores. The addition of herbivores increased the number of cases by 40% in which the invader had higher
growth rates. Our results suggest that low grazing pressure on S. muticum by the recipient herbivore community may give the invader a competitive advantage over at least part of the native seaweed
community, thereby contributing to the invasiveness of S. muticum along the Portuguese coast. 相似文献
880.
Estimation of urban sensible heat flux using a dense wireless network of observations 总被引:1,自引:0,他引:1
Daniel F. Nadeau W. Brutsaert M. B. Parlange E. Bou-Zeid G. Barrenetxea O. Couach M.-O. Boldi J. S. Selker M. Vetterli 《Environmental Fluid Mechanics》2009,9(6):635-653
The determination of the sensible heat flux over urban terrain is challenging due to irregular surface geometry and surface
types. To address this, in 2006–07, a major field campaign (LUCE) took place at the école Polytechnique Fédérale de Lausanne
campus, a moderately occupied urban site. A distributed network of 92 wireless weather stations was combined with routine
atmospheric profiling, offering high temporal and spatial resolution meteorological measurements. The objective of this study
is to estimate the sensible heat flux over the built environment under convective conditions. Calculations were based on Monin–Obukhov
similarity for temperature in the surface layer. The results illustrate a good agreement between the sensible heat flux inferred
from the thermal roughness length approach and independent calibrated measurements from a scintillometer located inside the
urban canopy. It also shows that using only one well-selected station can provide a good estimate of the sensible heat flux
over the campus for convective conditions. Overall, this study illustrates how an extensive network of meteorological measurements
can be a useful tool to estimate the sensible heat flux in complex urban environments. 相似文献