全文获取类型
收费全文 | 1670篇 |
免费 | 17篇 |
国内免费 | 10篇 |
专业分类
安全科学 | 41篇 |
废物处理 | 108篇 |
环保管理 | 128篇 |
综合类 | 145篇 |
基础理论 | 367篇 |
环境理论 | 2篇 |
污染及防治 | 620篇 |
评价与监测 | 184篇 |
社会与环境 | 98篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 23篇 |
2022年 | 54篇 |
2021年 | 73篇 |
2020年 | 35篇 |
2019年 | 27篇 |
2018年 | 51篇 |
2017年 | 68篇 |
2016年 | 98篇 |
2015年 | 49篇 |
2014年 | 102篇 |
2013年 | 146篇 |
2012年 | 93篇 |
2011年 | 137篇 |
2010年 | 100篇 |
2009年 | 75篇 |
2008年 | 86篇 |
2007年 | 122篇 |
2006年 | 86篇 |
2005年 | 54篇 |
2004年 | 36篇 |
2003年 | 39篇 |
2002年 | 45篇 |
2001年 | 23篇 |
2000年 | 11篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1991年 | 4篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1964年 | 1篇 |
1915年 | 1篇 |
排序方式: 共有1697条查询结果,搜索用时 171 毫秒
311.
Jesús Cambrollé Juan Manuel Mancilla-Leytón Sara Muñoz-Vallés Beatriz Morenza-Barrera Manuel Enrique Figueroa 《Journal of Coastal Conservation》2018,22(6):1201-1207
Human pressure has been exponentially growing during recent decades in coastal areas, which have led to drastic losses of biodiversity in coastal ecosystems. The current conservation status of many coastal plant species is directly related to a lack of environmental criteria in the urban planning of coastal areas over recent decades. This study aimed to evaluate the evolution, over the last 9 years, of the conservation status of various populations of the endangered plant Glaucium flavum, exploring the extent to which human pressure and different management strategies practiced in the coastal areas where the populations are established have affected the conservation status of the species. The populations analysed have evolved in a different manner over the last 9 years, as have their threat factors, and a relationship was evident between their conservation status and the evolution of these different threat factors. Our results indicate that an appropriate planning of local management actions, such as the installation of walkways or the successful eradication of invasive species, may be determinant factors for successful conservation of the coastal vegetation. The presence of species that are sensitive to slight changes in the ecosystem, and the main factors that govern the plant performance of these species, must be given full consideration in decision-making processes of coastal planning and management. 相似文献
312.
Gabriel Núñez-Antonio Manuel Mendoza Alberto Contreras-Cristán Eduardo Gutiérrez-Peña Eduardo Mendoza 《Environmental and Ecological Statistics》2018,25(4):471-494
The study of the interaction among species is an active area of research in Ecology. In particular, it is of interest to evaluate the overlap of their ecological niches. Temporal activity is one of the niche’s axes most commonly used to explore ecological segregation among animal species, and many contributions focus on the overlap of this variable. Once the information of the temporal activity is obtained in the wild, the data is treated as a random sample. There exist different methods to estimate the overlap. Specifically, in the case of two species, one possibility is to estimate the density of the temporal activity of each species and then evaluate the overlap between these density functions. This leads naturally to the analysis of circular data. Most of the procedures currently in use impose some rather restrictive assumptions on the probabilistic models used to describe the phenomena, and only provide approximate measures of the uncertainty involved in the process. In this article, we propose a Bayesian nonparametric approach which incorporates a well-defined noninformative prior. We take advantage of the data structure to define such a prior in terms of the predictive distribution. To the best of our knowledge, this is a novel approach. Our procedure is compared with a well-known method using simulated data, and applied to the analysis of real camera-trap data concerning two mammalian species from the El Triunfo biosphere reserve (Chiapas, Mexico). 相似文献
313.
Sophie Quérouil Luís Freitas Irma Cascão Filipe Alves Ana Dinis Joana R. Almeida Rui Prieto Silvia Borràs José A. Matos Diogo Mendonça Ricardo S. Santos 《Marine Biology》2010,157(11):2567-2580
Several cetacean species exhibit fine-scale population structure despite their high dispersal capacities and the apparent continuity of the marine environment. In dolphins, most studies have focused on coastal areas and continental margins, and they revealed differentiated populations within relatively small geographic areas, sometimes in conjunction with a specialisation for different habitats (ecotypes). We analysed the population genetic structure of short-beaked common dolphins (Delphinus delphis) and Atlantic spotted dolphins (Stenella frontalis) in the Azores and Madeira, the two most isolated archipelagos of the North Atlantic. The archipelago of the Azores is divided into three groups of islands and stands 900 km away from Madeira. It is not known whether individuals migrate between groups of islands and archipelagos, nor whether distinct ecotypes are present. These questions were investigated by genetic analyses of 343 biopsy samples collected on free-ranging dolphins. The analyses consisted in sequencing part of the mitochondrial hyper-variable region, screening up to 14 microsatellite loci, and molecular sexing. Results did not unravel any population structure at the scale of the study area. Lack of differentiation matches expectations for spotted dolphins, which are transient in both archipelagos, but not for common dolphins, which are present year-round in the Azores and potentially resident. Absence of genetic structure over hundreds and even thousands of kilometres implies the existence of gene flow over much larger distances than usually documented in small delphinids, which could be achieved through individual movements. This finding indicates that population structure in oceanic habitat differs from that observed in coastal habitat. 相似文献
314.
Rocío Moreno Lluís Jover Ignacio Munilla Alberto Velando Carola Sanpera 《Marine Biology》2010,157(3):545-553
The widespread omnivory of consumers and the trophic complexity of marine ecosystems make it difficult to infer the feeding
ecology of species. The use of stable isotopic analysis plays a crucial role in elucidating trophic interactions. Here we
analysed δ15N, δ13C and δ34S in chick feathers, and we used a Bayesian triple-isotope mixing model to reconstruct the diet of a generalist predator,
the yellow-legged gull (Larus michahellis) that breeds in the coastal upwelling area off northwest mainland Spain. The mixing model indicated that although chicks
from all colonies were fed with a high percentage of fish, there are geographical differences in their diets. While chicks
from northern colonies consume higher percentages of earthworms, refuse constitutes a more important source in the diet of chicks from western colonies. The three-isotope mixing model revealed
a heterogeneity in foraging habitats that would not have been apparent if only two stable isotopes had been analysed. Moreover,
our work highlights the potential of adding δ34S for distinguishing not only between terrestrial and marine prey, but also between different marine species such as fish,
crabs and mussels. 相似文献
315.
João Paulo Silva Author Vitae Mário Santos Author Vitae Author Vitae Domingos Leitão Author Vitae Author Vitae Márcia Pinto Author Vitae Author Vitae João Alexandre Cabral Author Vitae 《Ecological modelling》2010,221(16):1954-1963
Collision with conductors and earth cables is a known impact generated by transmission power lines, however there is virtually no information on how these infrastructures might affect bird distribution in a landscape context. With this work we specifically hypothesise that transmission power lines may affect the occurrence of a threatened bird, the little bustard (Tetrax tetrax). To test this hypothesis we used a Stochastic Dynamic Methodology (StDM), analysing the effects of power lines in a landscape perspective and simulating population trends as a response to power line installation and habitat changes induced by agricultural shifts in southern Portugal. The data used in the dynamic model construction included relevant gradients of environmental conditions and was sampled during the breeding seasons of 2003-2006. Transmission power lines were significantly avoided by the little bustard and the developed StDM model showed that the distance to these utility structures is the most important factor determining breeding densities in sites with suitable habitat for the species, which possibly leads to displacement of populations and habitat fragmentation. The model simulations also provided the base to analyse the cumulative effects caused by the habitat degradation that can ultimately lead to the extinction of local populations. Within priority conservation sites, the dismantling of existing transmission lines should be considered whenever possible, in order to ensure adequate breeding habitat. The model is considered useful as an auxiliary tool to be used in environmental impact assessments, management and conservation studies. 相似文献
316.
Iñaki Rodríguez-Prieto José Martín Esteban Fernández-Juricic 《Behavioral ecology and sociobiology》2010,64(12):1937-1945
Habituation to nonlethal predation stimuli may provide benefits for animals living in areas with frequent encounters with
low-risk predators. On the other hand, individuals can be very consistent in their antipredator responses, with shy individuals
showing greater degree of responsiveness than bold individuals. However, the link between habituation or boldness and individual
benefits has not been thoroughly investigated. We established whether and how two behavioral components associated with antipredator
responses (habituation and boldness, and their interaction) would influence body condition, which is a parameter related to
fitness. We conducted an outdoor semi-natural experiment with Iberian wall lizards (Podarcis hispanica). Individual boldness was consistent across contexts, but we did not find any effect of boldness or the interaction between
boldness and habituation on body condition. However, those individuals that habituated more readily to a frequent predatory
stimulus were able to increase their body condition more relative to lizards that habituated less. This finding highlights
the importance of individual differences in behavioral plasticity, which could influence traits related to fitness. Habituation
can provide benefits for individuals exposed to low-risk predators; however, individuals more prone to habituation could also
experience mortality costs by wrongly habituating to a dangerous predator. 相似文献
317.
Juan C. Alonso Marina Magaña Carlos Palacín Carlos A. Martín 《Behavioral ecology and sociobiology》2010,64(10):1589-1600
We examined how mating success varied in relation to age, weight, body size, and display behavior among great bustard Otis tarda males. The estimated mating success was strongly skewed, with 45% of adult males being involved in copulation attempts and
only 9.7% actually seen copulating successfully. Unlike most birds, body size continued increasing in great bustards several
years after reaching sexual maturity. Age, weight, and display effort were all significant and independent predictors of male
mating success. The higher display effort involved performing longer full-display bouts. Older males could detach from the
male flock earlier in the season as well as on each day and spend longer seasonal and daily periods displaying as solitary
birds, which contributed to increase their mating success. In contrast, males weighing more did not invest more in display,
which suggests that they could be recognized as dominants by other males and selected by females through assessment of their
plumage sexual traits. In contrast to most other bird species, the system described for great bustards resembles that found
in some lek-mating ungulates, where social rank is a complex trait determined by both age and mass, and as in these mammals,
it suggests that sexual selection continues to favor a high male weight in this extremely sexually dimorphic species. 相似文献
318.
Dorota Molek-Winiarska Dorota Żołnierczyk-Zreda 《International journal of occupational safety and ergonomics》2013,19(4):546-556
Purpose. The aim of this article was to check whether mindfulness-based stress reduction (MBSR) is an effective intervention in reducing work-related stress in the case of workers in a copper mine. Methods. Sixty six employees were randomized to the experimental group (32 participants) or to the control group (34 participants). Work-related stress was measured using the job content questionnaire (JCQ) and mental health was measured using the general health questionnaire (GHQ-28) Experimental manipulation was 40-h MBSR training. Results. Multivariate repeated-measures analysis of variance revealed a significant increase of JCQ decision latitude (F?=?17.36, p?<?0.001) and social support (supervisor F?=?9.00, p?<?0.004; coworker F?=?5.61, p?<?0.020), and a significant decrease in GHQ-28 anxiety (F?=?5.28, p?<?0.079) and depression (F?=?3.95, p?<?0.048) due to the intervention. Conclusions. The study confirms that MBSR can be effective in reducing stress resulting from the external risk (and/or imagined fear) of losing one’s health or life. The use of MBSR could be recommended in health and safety activities in difficult and dangerous work conditions, such as mining, to promote workers’ well-being. 相似文献
319.
Xochitl Cruz-Núñez Luis Conde Luis G. Ruiz-Suárez 《Mitigation and Adaptation Strategies for Global Change》2008,13(2):179-191
Intergovernmental Panel on Climate Change (IPCC) Tier 1 key sources level 1 assessment was applied to the 1994–1994 National
Greenhouse Gases (GHG) emission inventory for Mexico in order to identify and analyze the key sources within it. Top key sources
were from land use change and energy combustion contributing to about 60% of total national emissions. In addition, a Tier
1 trend assessment revealed some changes with respect to Tier 1 level assessment: Top key sources according to this analysis
are waste disposal and delayed emissions from land clearing. Important insight for cost effective preventive mitigation actions
can be extracted from this analysis. A comparison with other countries was carried out to find similarities in the GHG national
emissions inventories related to common features on economic development. 相似文献
320.
Gómara B González MJ Baos R Hiraldo F Abad E Rivera J Jiménez B 《Environment international》2008,34(1):73-78
This study provides information on the current status of contamination by organochlorines (DDTs, PCBs, PCDDs and PCDFs) in the declining red kite (Milvus milvus L.) population breeding in the Do?ana National Park (DNP), south-western Spain. Analyses were performed in addled eggs collected between 1999 and 2001. DDE concentrations ranged from 0.1 to 33.5 microg/g ww, representing more than 86% of the total DDTs. Of the samples studied, 50% showed DDE levels above those associated with reproductive impairment in other raptor species. Concentrations of ortho PCBs (average 36.8 microg/g ww+/-37.7) in 50% of the eggs were much higher than levels reported to cause reduced hatching success, embryo mortality, and deformities in birds (>20 microg/g ww). It is remarkable that average ortho PCB and DDE concentrations showed an increase of one order of magnitude compared to previous data for the species during the 80s. Total PCDD/Fs showed levels in the low pg/g range (7.2-42 pg/g ww), having PCDDs and PCDFs similar contributions in most samples. Total mean TEQs were 238 pg/g (ww), being the range 7.02-667 pg/g (ww). Spatial variation within DNP was observed for PCBs, DDTs, as well as for TEQs. Since some eggs exceeded the NOEL (67%) and LOEL (33%) reported for other raptor species, we would expect the red kite to experience detrimental effects to dioxin-like toxicity. Our results suggest that organochlorine contaminants should be regarded as an element of concern in the population under study, in addition to other conservation problems already reported. Further investigations should be undertaken to identify potential sources of these chemicals in DNP, and to find out if organochlorine contamination is present in other predator species in the area, as well as their potential health effects on individuals and/or populations. 相似文献