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91.
Peter Witzgall Jean-Pierre Chambon Marie Bengtsson C. Rikard Unelius Monica Appelgren Gyorgy Makranczy N. Muraleedharan Darwin W. Reed Klaus Hellrigl Hans-Ruedi Buser Eric Hallberg Gunnar Bergström Miklos Tóth Christer Löfstedt Jan Löfqvist 《Chemoecology》1996,7(1):13-23
Summary The geometric isomers (E,E)-, (E,Z)-, (Z,E)-, and (Z,Z)-8,10-dodecadien-1-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males ofCydia andGrapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds.Pammene, as well as otherGrapholita andCydia responded to the monoenic 8- or 10-dodecen-1-yl acetates. Of the tribes Olethreutini and Eucosmini,Hedya, Epiblema, Eucosma, andNotocelia trimaculana were also attracted to 8,10-dodecadien-1-yl acetates, but several otherNotocelia to 10,12-tetradecadien-1-yl acetates. The female sex pheromones ofC. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella andNotocelia roborana were identified. (E,E)- and (E,Z)-8,10-dodecadien-1-yl acetate are producedvia a commonE9 desaturation pathway inC. splendana. CallingC. nigricana andC. fagiglandana females are attracted to wingfanning males. 相似文献
92.
Marie Larchevêque Nicolas Monts Virginie Baldy Sylvie Dupouyet 《Agriculture, ecosystems & environment》2005,110(3-4):241-248
On Mediterranean calcareous soils, high fire frequency induces soil impoverishment and the development of stable Quercus coccifera garrigues. Organic amendment could increase soil fertility levels, and could alter the vegetation dynamics and the established dominance relationships. In this study, the plant cover evolution is monitored in an amended burnt shrub during two years. Three treatments are studied: control (D0), 50 t ha−1 (D50) and 100 t ha−1 (D100) of fresh co-composted sewage sludge and greenwastes.First, the spreading process leads to the squashing of the vegetation, whose intensity reaches a threshold on D100 and limits the woody species’ recovery after amendment. Consequently, the dominant herb Brachypodium retusum is favoured. On D50, woody species are favoured compared to herbs, probably due to the space colonization strategy of Q. coccifera after squashing. Thus, compost at both rates favours the two dominant resprouter species until they have colonized all the free space created by squashing.Secondly, compost has some fertilizing effects on Rosmarinus officinalis and Ulex parviflorus, that improves their cover on D50. However, compost also increases U. parviflorus’ sensitivity to drought.At the end of the experiment, a third compost effect appears, as seeder cover becomes greater than D0 on D50. After amendment, compost covers rocky stones, which creates a new territory where species with superficial rooting can establish (mulch effect). 相似文献
93.
Ton Snelder Anthony Lehmann Nicolas Lamouroux John Leathwick Karin Allenbach 《Environmental management》2010,45(5):939-952
Ecological regionalizations define geographic regions exhibiting relative homogeneity in ecological (i.e., environmental and
biotic) characteristics. Multivariate clustering methods have been used to define ecological regions based on subjectively
chosen environmental variables. We developed and tested three procedures for defining ecological regions based on spatial
modeling of a multivariate target pattern that is represented by compositional dissimilarities between locations (e.g., taxonomic
dissimilarities). The procedures use a “training dataset” representing the target pattern and models this as a function of
environmental variables. The model is then extrapolated to the entire domain of interest. Environmental data for our analysis
were drawn from a 400 m grid covering all of Switzerland and consisted of 12 variables describing climate, topography and
lithology. Our target patterns comprised land cover composition of each grid cell that was derived from interpretation of
aerial photographs. For Regionalization 1 we used conventional cluster analysis of the environmental variables to define 60
hierarchically organized levels comprising from 5 to 300 regions. Regionalization 1 provided a base-case for comparison with
the model-based regionalizations. Regionalization 2, 3 and 4 also comprised 60 hierarchically organized levels and were derived
by modeling land cover composition for 4000 randomly selected “training” cells. Regionalization 2 was based on cluster analysis
of environmental variables that were transformed based on a Generalized Dissimilarity Model (GDM). Regionalization 3 and 4
were defined by clustering the training cells based on their land cover composition followed by predictive modeling of the
distribution of the land cover clusters using Classification and Regression Tree (CART) and Random Forest (RF) models. Independent
test data (i.e. not used to train the models) were used to test the discrimination of land cover composition at all hierarchical
levels of the regionalizations using the classification strength (CS) statistic.
CS for all the model-based regionalizations was significantly higher than for Regionalization 1. Regionalization 3 and 4 performed
significantly better than Regionalization 2 at finer hierarchical levels (many regions) and Regionalization 4 performed significantly
better than Regionalization 3 for coarse levels of detail (few regions). Compositional modeling can significantly increase
the performance of numerically defined ecological regionalizations. CART and RF-based models appear to produce stronger regionalizations
because discriminating variables are able to change at each hierarchic level. 相似文献
94.
Thomas Eglin Christophe Francois Alice Michelot Nicolas Delpierre Claire Damesin 《Ecological modelling》2010,221(15):1779-1797
Stable carbon isotopic composition (δ13C) in tree rings is a widely recognized tool for climate reconstruction, and several works suggest that seasonal information can be extracted from intra-ring δ13C variations. In this study, we explored the link between climate and intra-seasonal oak ring δ13C using a process-based modelling approach. The ISOCASTANEA model was developed to compute the seasonal dynamics of tree-ring δ13C for deciduous species from half-hourly climatic data by accounting for photosynthetic discrimination and carbon translocation and allocation at the tree scale and in tree rings.The model was applied from March 2005 to December 2007 in a 150-year-old deciduous oak forest. Canopy photosynthesis and stomatal conductance were calibrated using H2O and CO2 fluxes measured by the eddy flux technique, and simulated δ13C values were compared to seasonal patterns of total organic matter δ13C measured in tree rings for 2006 and 2007 at the same site. With the inclusion of carbon translocation and with regard to 13C enrichment of starch compared to soluble sugars, the model can reasonably simulate the intra-seasonal and inter-annual variability of tree-ring δ13C using the same parameter values for 2006 and 2007. The amplitude of the seasonal carbon isotope pattern in tree rings was influenced by both photosynthetic and post-photosynthetic processes (starch enrichment and reserve use). The δ13C variations in the early part of the ring, i.e., mainly in the earlywood, were related mostly to carbohydrate metabolism, although diluted information about environmental conditions during the previous year could also be found. The last part of the ring, consisting mainly of latewood, was found to be a good recorder of current-year environmental conditions, in particular relative humidity, at a fine temporal resolution when the growth rate was high. The sensitivity of the δ13C in the early part of the ring to carbohydrate metabolism suggests that intra-ring δ13C could be used to explore the relationship between tree decline or mortality and carbohydrate deficiency. 相似文献
95.
Kamran Moradkhani Laurence Cuisset Pierre Boisseau Olivier Pichon Marine Lebrun Houda Hamdi-Rozé Marie-Laure Maurin Nicolas Gruchy Marie-Christine Manca-Pellissier Perrine Malzac Frédéric Bilan Marie-Pierre Audrezet Pascale Saugier-Veber Anne-Laure Fauret-Amsellem Chantal Missirian Paul Kuentz Gregory Egea Agnès Guichet Isabelle Creveaux Caroline Janel Ines Harzallah Renaud Touraine Carole Goumy Nicole Joyé Jacques Puechberty Emmanuelle Haquet Sandra Chantot-Bastaraud Sébastien Schmitt Philippe Gosset Bénédicte Duban-Bedu Bruno Delobel Philippe Vago François Vialard Denise Molina Gomes Jean-Pierre Siffroi Jean-Paul Bonnefont Jean-Michel Dupont Philippe Jonveaux Martine Doco-Fenzy Damien Sanlaville Cédric Le Caignec 《黑龙江环境通报》2019,39(11):986-992
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