全文获取类型
收费全文 | 3876篇 |
免费 | 38篇 |
国内免费 | 21篇 |
专业分类
安全科学 | 91篇 |
废物处理 | 238篇 |
环保管理 | 328篇 |
综合类 | 456篇 |
基础理论 | 866篇 |
环境理论 | 4篇 |
污染及防治 | 1301篇 |
评价与监测 | 364篇 |
社会与环境 | 276篇 |
灾害及防治 | 11篇 |
出版年
2023年 | 36篇 |
2022年 | 102篇 |
2021年 | 89篇 |
2020年 | 46篇 |
2019年 | 68篇 |
2018年 | 124篇 |
2017年 | 119篇 |
2016年 | 178篇 |
2015年 | 119篇 |
2014年 | 184篇 |
2013年 | 378篇 |
2012年 | 222篇 |
2011年 | 297篇 |
2010年 | 181篇 |
2009年 | 164篇 |
2008年 | 223篇 |
2007年 | 231篇 |
2006年 | 174篇 |
2005年 | 155篇 |
2004年 | 113篇 |
2003年 | 96篇 |
2002年 | 96篇 |
2001年 | 87篇 |
2000年 | 54篇 |
1999年 | 36篇 |
1998年 | 20篇 |
1997年 | 24篇 |
1996年 | 14篇 |
1995年 | 30篇 |
1994年 | 22篇 |
1993年 | 13篇 |
1992年 | 16篇 |
1991年 | 16篇 |
1990年 | 18篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1967年 | 5篇 |
1966年 | 6篇 |
1964年 | 11篇 |
1963年 | 9篇 |
1962年 | 11篇 |
1960年 | 8篇 |
1958年 | 13篇 |
1957年 | 5篇 |
1956年 | 5篇 |
排序方式: 共有3935条查询结果,搜索用时 31 毫秒
991.
Kiran L. Dhanjal‐Adams Marcel Klaassen Sam Nicol Hugh P. Possingham Iadine Chadès Richard A. Fuller 《Conservation biology》2017,31(3):646-656
Conserving migratory species requires protecting connected habitat along the pathways they travel. Despite recent improvements in tracking animal movements, migratory connectivity remains poorly resolved at a population level for the vast majority of species, thus conservation prioritization is hampered. To address this data limitation, we developed a novel approach to spatial prioritization based on a model of potential connectivity derived from empirical data on species abundance and distance traveled between sites during migration. We applied the approach to migratory shorebirds of the East Asian‐Australasian Flyway. Conservation strategies that prioritized sites based on connectivity and abundance metrics together maintained larger populations of birds than strategies that prioritized sites based only on abundance metrics. The conservation value of a site therefore depended on both its capacity to support migratory animals and its position within the migratory pathway; the loss of crucial sites led to partial or total population collapse. We suggest that conservation approaches that prioritize sites supporting large populations of migrants should, where possible, also include data on the spatial arrangement of sites. 相似文献
992.
J.J. Cerón E. Sancho MD. Ferrando C. Gutierrez E. Andreu 《Journal of environmental science and health. Part. B》2013,48(5):1029-1040
Abstract Eels were exposed to a sublethal diazinon concentration of 0.042 mg/L for exposure times of 6, 24, 48, 72 and 96 hours. Biochemical analyses of blood composition, such as plasma glucose, total plasma cholesterol and triglycerides, plasma lactate, plasma urea and uric acid, showed significant differences between treated and control animals. Plasma glucose and lactate increased after 6 hours exposure to the insecticide. Plasma cholesterol and triglycerides content decreased during 96 hours treatment. Urea levels increased at 72 hours while uric acid content decreased significantly at 24, 72 and 96 hours exposure to the pesticide. The observed effects of diazinon on eel metabolism suggested that the treated fish was faced with a serious metabolic crisis, and the fish looked for alternative methods of metabolism to overcome the toxic stress. 相似文献
993.
I. González-Aparicio J. Hidalgo A. Baklanov A. Padró O. Santa-Coloma 《Environmental science and pollution research international》2013,20(7):4469-4483
There is extensive evidence of the negative impacts on health linked to the rise of the regional background of particulate matter (PM) 10 levels. These levels are often increased over urban areas becoming one of the main air pollution concerns. This is the case on the Bilbao metropolitan area, Spain. This study describes a data-driven model to diagnose PM10 levels in Bilbao at hourly intervals. The model is built with a training period of 7-year historical data covering different urban environments (inland, city centre and coastal sites). The explanatory variables are quantitative—log [NO2], temperature, short-wave incoming radiation, wind speed and direction, specific humidity, hour and vehicle intensity—and qualitative—working days/weekends, season (winter/summer), the hour (from 00 to 23 UTC) and precipitation/no precipitation. Three different linear regression models are compared: simple linear regression; linear regression with interaction terms (INT); and linear regression with interaction terms following the Sawa’s Bayesian Information Criteria (INT-BIC). Each type of model is calculated selecting two different periods: the training (it consists of 6 years) and the testing dataset (it consists of 1 year). The results of each type of model show that the INT-BIC-based model (R 2?=?0.42) is the best. Results were R of 0.65, 0.63 and 0.60 for the city centre, inland and coastal sites, respectively, a level of confidence similar to the state-of-the art methodology. The related error calculated for longer time intervals (monthly or seasonal means) diminished significantly (R of 0.75–0.80 for monthly means and R of 0.80 to 0.98 at seasonally means) with respect to shorter periods. 相似文献
994.
Silvestre García de Jalón Silvia Silvestri Andrew P. Barnes 《Regional Environmental Change》2017,17(2):399-410
Livestock systems play an important role in the livelihoods of many rural communities in Sub-Saharan Africa while being responsible for an important share of human-induced greenhouse gas emissions. This study aimed to evaluate the potential for adoption of climate smart agricultural practices in Sub-Saharan livestock systems, related to the improvement in feed, animal husbandry, and grassland management. These practices present productivity and mitigation benefits and in some cases may also contribute to enhance resilience. In this study, we used a data set of 1538 farm households across nine Sub-Saharan countries. A mixed logit model was used to assess the influence on adoption and to estimate the probability of adoption. Our results show that there seems to be stronger influence of physical and financial capitals on adoption than the other capitals. Different types of capitals influence the uptake of different agricultural practices. Yet the probability of adoption would change across countries. The results of this study could help to refine adoption estimates calculated through global or regional modelling approaches and to inform the design of policies to better target investments in order to foster adoption. 相似文献
995.
Wolke Tobón Tania Urquiza‐Haas Patricia Koleff Matthias Schröter Rubén Ortega‐Álvarez Julio Campo Roberto Lindig‐Cisneros José Sarukhán Aletta Bonn 《Conservation biology》2017,31(5):1086-1097
Ecological restoration has become an important strategy to conserve biodiversity and ecosystems services. To restore 15% of degraded ecosystems as stipulated by the Convention on Biological Diversity Aichi target 15, we developed a prioritization framework to identify potential priority sites for restoration in Mexico, a megadiverse country. We used the most current biological and environmental data on Mexico to assess areas of biological importance and restoration feasibility at national scale and engaged stakeholders and experts throughout the process. We integrated 8 criteria into 2 components (i.e., biological importance and restoration feasibility) in a spatial multicriteria analysis and generated 11 scenarios to test the effect of assigning different component weights. The priority restoration sites were distributed across all terrestrial ecosystems of Mexico; 64.1% were in degraded natural vegetation and 6% were in protected areas. Our results provide a spatial guide to where restoration could enhance the persistence of species of conservation concern and vulnerable ecosystems while maximizing the likelihood of restoration success. Such spatial prioritization is a first step in informing policy makers and restoration planners where to focus local and large‐scale restoration efforts, which should additionally incorporate social and monetary cost–benefit considerations. 相似文献
996.
Verónica Quirici Sylvain Faugeron Loren D. Hayes Luis A. Ebensperger 《Behavioral ecology and sociobiology》2011,65(4):787-798
In social or group living species, members of groups are expected to be affected differentially by competition through the
effect of group size (i.e., the “social competition hypothesis”). This hypothesis predicts an increase in the probability
of dispersal with increasing size of social groups. At a more mechanistic level and based on the known effects of competition
on stress hormone levels, a positive relationship between group size and glucocorticoids of juveniles should be observed.
We used a demographic approach to test these predictions on a natural population of the communally rearing and semifossorial
rodent—Octodon degus. Burrow systems provide degus with places to rear offspring and to evade stressful thermal conditions and predators. Thus,
we predicted dispersal to increase with increasing number of degus per main burrow system used, a measure of habitat saturation
in degus. The probability of dispersal increased with increasing number of degus per main burrow system used. Mean fecal metabolites
of cortisol in offspring increased, yet not statistically significantly, with the number of juveniles in groups. These results
were consistent with a scenario in which competition drives natal dispersal in juveniles in social degus. In particular, competition
would be the consequence of high degu abundance in relation to the abundance of burrow systems available at the time of offspring
emergence. 相似文献
997.
Matías Salvo Andrés Lizasoain Matías Castells Viviana Bortagaray Sebastián Castro Rodney Colina Fernando Lopez Tort Matías Victoria 《Food and environmental virology》2018,10(2):193-200
Human bocavirus (HBoV) infections are related to respiratory and gastroenteric diseases. The aim of this study was to investigate the presence of HBoV in both sewage and surface waters in Uruguay. Sixty-eight sewage samples from the cities of Salto, Paysandú, Bella Unión, Fray Bentos, Treinta y Tres and Melo and 36 surface water samples from the cities of Salto, Florida and Santa Lucía were studied. HBoV was screened by multiplex qPCR for the detection of the four subtypes, followed by monoplex qPCRs for the independent quantification of each subtype. A qualitative PCR followed by DNA sequencing and phylogenetic analysis was carried out for molecular characterization of HBoV strains. HBoV was present in a high frequency (69%) in sewage and only one positive sample (3%) was found in surface water. Concerning sewage samples, HBoV1 was detected in 11 (23%) out of the 47 positives samples, with a mean concentration of 8.2 × 104 genomic copies/Liter (gc/L), HBoV3 was detected in 35 (74%) of the positive samples with a mean concentration of 4.1 × 106 gc/L and subtypes 2 and/or 4 were detected in 39 (83%) of the positive samples with a mean concentration of 7.8 × 106 gc/L. After the phylogenetic analysis performed by a Bayesian approach, the four HBoV subtypes were confirmed. This is the first study determining a high frequency of HBoV and the presence of the four HBoV subtypes in aquatic matrices in Latin America, mainly in sewage. Although HBoV was scarcely detected in surface water, a waterborne transmission is likely to occur if people enter in contact with polluted surface waters for recreational activities such as fishing or swimming since an elevated frequency of HBoV was detected in raw sewage which is usually directly discharged into surface waters. 相似文献
998.
Stefano Ambroso Andrea Gori Carlos Dominguez-Carrió Josep-Maria Gili Elisa Berganzo Núria Teixidó Michael Greenacre Sergio Rossi 《Marine Biology》2013,160(12):3059-3070
Current knowledge on the abundance and distribution patterns of different soft coral species is relatively limited when compared to other benthic suspension feeders such as gorgonians and hard coral species. To overcome this scarcity of information, the distribution patterns of the soft corals Alcyonium acaule and Alcyonium palmatum were investigated in northwestern Mediterranean benthic communities over a wide geographical (60 km of coastline) and bathymetrical (0–70 m depth) extent using a remotely operated vehicle. A. acaule was the most abundant species in the study area with highest recorded density of 18 col m?2 found at depths of 35–45 m in areas that are directly exposed to strong near-bottom currents. Conversely, A. palmatum was only found as scattered solitary colonies at greater depths in soft bottoms, with maximum density of 2.4 col m?2. Medium and large colonies of A. acaule were preferentially found on sloping and vertical rocky bottoms where they form dense patches. High-density patches of A. acaule were preferentially found on vertical rocky bottom, while isolated colonies were preferentially observed on coralligenous substrata as well as on flat soft and maërl substrates. A. acaule biomass distribution showed highest values between 40 and 45 m depth, and between 60 and 65 m depth. This suggests that deeper populations are formed by colonies that are bigger than the equivalent shallower ones. Although both species are almost genetically identical, ecologically they are very different. For this reason, conservation plans should consider the differential ecological traits shown by these two soft coral species. 相似文献
999.
1000.
Cristal Fernández-Gómez José Antonio López-López Victor Matamoros Sergi Díez Manuel García-Vargas Carlos Moreno 《Environmental monitoring and assessment》2013,185(4):3209-3218
In the lower Guadalquivir river basin, a system stressed by a wide variety of anthropogenic activities, eight pesticides (four triazines, two chloroacetanilide herbicides, one organochlorine, and one organophosphorus insecticide); and four emerging pollutants (two personal care products, one organophosphorous flame retardant, and one xanthine alkaloid) were analyzed in river water during a 2-year monitoring program, and after rain episodes. Samples were extracted using the solid phase extraction (SPE) technique prior to determination of compounds using gas chromatograph coupled to a mass spectrometer detector. Except for caffeine, recoveries were mostly above 80 %, while limits of detection and quantification were in the low nanograms per liter level (except for dimethoate). Terbuthylazine, simazine (triazine herbicides), and dimethoate (organophosphorus insecticide), present in agrochemicals, were predominant in the river water, although concentrations were below the quality standards established by the EU Water-Framework-Directive. A general trend to increase concentration was observed after rain events, in particular for pesticides, possibly as a consequence of surface runoff. 相似文献