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511.
Space limitation in larval settlement can play an important role in the population dynamics of marine species. A novel statistical
test for space limitation based on quadrat counts of individuals is described. The test is based on identifying a significant
relationship between the relative dispersion of quadrat counts and overall mean density. An application to a time series of
quadrat counts of recently settled American lobsters Homarus americanus covering the period 1993–2007 in Casco Bay, Maine, USA (43°45′N; 69°58′W), is presented. For this data set, the null hypothesis
that space is not limiting could not be rejected (P = 0.10). 相似文献
512.
513.
Rosamond?GodwinEmail author Ian?Brown Steven?Montgomery Stewart?Frusher Timothy?Green Jennifer?Ovenden 《Marine Biology》2012,159(1):77-86
Telomere length has been purported as a biomarker for age and could offer a non-lethal method for determining the age of wild-caught
individuals. Molluscs, including oysters and abalone, are the basis of important fisheries globally and have been problematic
to accurately age. To determine whether telomere length could provide an alternative means of ageing molluscs, we evaluated
the relationship between telomere length and age using the commercially important Sydney rock oyster (Saccostrea glomerata). Telomere lengths were estimated from tissues of known age individuals from different age classes, locations and at different
sampling times. Telomere length tended to decrease with age only in young oysters less than 18 months old, but no decrease
was observed in older oysters aged 2–4 years. Regional and temporal differences in telomere attrition rates were also observed.
The relationship between telomere length and age was weak, however, with individuals of identical age varying significantly
in their telomere length making it an imprecise age biomarker in oysters. 相似文献
514.
I.?Calderón Lucía?Pita S.?Brusciotti C.?Palacín X.?TuronEmail author 《Marine Biology》2012,159(1):187-197
Spatio-temporal variability in settlement and recruitment, high mortality during the first life-history stages, and selection
may determine the genetic structure of cohorts of long-lived marine invertebrates at small scales. We conducted a spatial
and temporal analysis of the common Mediterranean Sea urchin Paracentrotus
lividus to determine the genetic structure of cohorts at different scales. In Tossa de Mar (NW Mediterranean), recruitment was followed
over 5 consecutive springs (2006–2010). In spring 2008, recruits and two-year-old individuals were collected at 6 locations
along East and South Iberian coasts separated from 200 to over 1,100 km. All cohorts presented a high genetic diversity based
on a fragment of mtCOI. Our results showed a marked genetic homogeneity in the temporal monitoring and a low degree of spatial
structure in 2006. In 2008, coupled with an abnormality in the usual circulation patterns in the area, the genetic structure
of the southern populations studied changed markedly, with arrival of many private haplotypes. This fact highlights the importance
of point events in renewing the genetic makeup of populations, which can only be detected through analysis of the cohort structure
coupling temporal and spatial perspectives. 相似文献
515.
Kátya?G.?AbrantesEmail author Jayson?M.?Semmens Jeremy?M.?Lyle Peter?D.?Nichols 《Marine Biology》2012,159(1):57-64
Stable isotope analysis is increasingly used in ecological studies. Because lipid content influences δ13C, lipids should be removed from lipid-rich samples before δ13C analysis. To account for differences in δ13C arising from differences in lipid content, relationships between lipid content, C:N ratio and Δδ13C with lipid removal can be used to normalise lipid content to uniform levels. We investigate these relationships for salmonid
muscle and evaluate the suitability of previously published normalisation equations for these fish. Salmonids with a wide
range of condition (muscle lipid content = 3–35% of dry weight) were considered. There were no consistent relationships between
lipid content or C:N ratio and Δδ15N. There were linear relationships between C:N ratio and lipid content (L = −16.53 + 6.27 × C:N); C:N ratio and Δδ13C (Δδ13C = −1.87 + 0.65 × C:N); and lipid content and Δδ13C (Δδ13C = 0.01 + 0.10 × L), which should be used on salmonid stable isotope studies. 相似文献
516.
Tommy Kristensen Anders Isberg Nielsen Anders Isak J?rgensen Kim N. Mouritsen Henrik Glenner Jens T. Christensen J?rgen Lützen Jens T. H?eg 《Marine Biology》2012,159(9):2015-2023
Male crabs infected by parasitic barnacles (Rhizocephala) are known to be morphologically feminized. Here, we investigate morphological chances in green crabs, Carcinus maenas, induced by the parasitic barnacle Sacculina carcini. Infected males acquire a broader, longer and segmented abdomen, fringed with marginal setae. Copulatory appendages and pereopods are reduced in length, and the chelae become smaller. The feminization show great individual variation. Males with scars from lost externae, the parasites reproductive organ situated under the abdomen, are less modified than males carrying an externa, and the feminization is more pronounced in smaller than in larger males. No super-feminization is evident in female crabs that remain morphologically unaffected by infection. The protective value of a parasitically induced enlargement of the male abdomen may constitute an adaptation that increases parasite longevity. The additional effects on male morphology are viewed as pleiotropic side effects of the main adaptive value of enlarging the abdomen. 相似文献
517.
Dirk Erpenbeck John N. A. Hooper Isabelle Bonnard Patricia Sutcliffe Mayuri Chandra Pierre Perio Carsten Wolff Bernard Banaigs Gert W?rheide Cécile Debitus Sylvain Petek 《Marine Biology》2012,159(5):1119-1127
Sponges of the family Dysideidae (Dictyoceratida) are renowned for their diversity of secondary metabolites, and its genus Lamellodysidea, particularly Lamellodysidea herbacea, is the most studied taxon biochemically. Despite its importance, the taxonomic status of L. herbacea—whether it is a distinct species or a species complex—has never been assessed. Recent biochemical profiling revealed anti-plasmodial activity of brominated compounds in Lamellodysidea of the Pacific. Here, we present a comparative chemotaxonomic and molecular analysis of selected Dysideidae from the Pacific and the Indian Ocean (New Caledonia, Great Barrier Reef, Fiji, Mayotte, Guam, Palau). We investigated the phylogenetic relationships between the populations and assessed their bioactive (PBDE) compounds in order to unravel the taxonomic status of this commercially important group of sponges and assessed patterns of dispersal and biochemical variation. The molecular phylogeny was based on the internal transcribed ribosomal spacer and compared against a PBDE phylogeny for several specimens. Molecular data revealed a diversity of Indo-Pacific L. herbacea populations, also reflected by different PBDE compound profiles. Molecular and biochemical data also revealed a Lamellodysidea species new to science. Several specimens misidentified as Lamellodysidea were detected based on their position on different clades in the molecular phylogeny and their production of different halogenated compounds (brominated vs. chlorinated). The direct comparison of molecular and biochemical data also provided evidence for the occurrence of a host switch event and support for the theory that abiotic factors, such as sedimentation, affect the chemical constituents produced in L. herbacea. 相似文献
518.
519.
Emeline Pettex Svein-H?kon Lorentsen David Grémillet Olivier Gimenez Robert T. Barrett Jean-Baptiste Pons Céline Le Bohec Francesco Bonadonna 《Marine Biology》2012,159(12):2743-2756
The survival of marine predators depends on behavioural plasticity to cope with changes in prey distribution. Variability in behaviour might predict plasticity and is easier to assess than plasticity. Using miniaturized GPS loggers over several breeding seasons in two Norwegian Northern gannet (Morus bassanus) colonies, we investigated if and how the variability within and between individuals, but also between colonies and years, affected foraging strategies. Results revealed strong individual variability (foraging trip durations, foraging effort and different foraging areas). Individuals from both colonies showed preferred commuting routes, flight bearings and feeding hotspots. Individuals from the largest colony used larger and more foraging areas than individuals from the small colony. Feeding hotspots and foraging ranges varied amongst years in the largest colony only. Our study demonstrated that gannets show flexibility by changing prey fields that are driven by shifting oceanographic conditions. 相似文献
520.
Benoit Lebreton Pierre Richard Robert Galois Gilles Radenac Amel Brahmia Géraldine Colli Marig Grouazel Cyril André Ga?l Guillou Gérard F. Blanchard 《Marine Biology》2012,159(7):1537-1550
In an intertidal Zostera noltii Hornem seagrass bed, food sources used by sediment meiofauna were determined seasonally by comparing stable isotope signatures (δ13C, δ15N) of sources with those of nematodes and copepods. Proportions of different carbon sources used by consumers were estimated using the SIAR mixing model on δ13C values. Contrary to δ15N values, food source mean δ13C values encompassed a large range, from −22.1 ‰ (suspended particulate organic matter) to −10.0 ‰ (Z. noltii roots). δ13C values of copepods (from −22.3 to −12.3 ‰) showed that they use many food sources (benthic and phytoplanktonic microalgae, Z. noltii matter). Nematode δ13C values ranged from −14.6 to −11.4 ‰, indicating a strong role of microphytobenthos and/or Z. noltii matter as carbon sources. The difference of food source uses between copepods and nematodes is discussed in light of source accessibility and availability. 相似文献