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881.
ION‐SELECTIVE ELECTRODES IN ANALYTICAL CHEMISTRY, Vol. 2 by H. Freiser (ed.), Plenum Press, New York, 1980. CARCINOGENESIS AND MUTAGENESIS by Myron A. Mehlman, Morris F. Cranmer and Raymond E. Shapiro, from the Journal of Environmental Pathology and Toxicology (Official Organ of the American College of Toxicology), 388 pages and 135 tables and figures, 1977, linen, format 261 × 178 mm, ISBN 0–930376–02–1, printed by Pathotox Publishers, Inc., Park Forest South, Illinois 60466, $23.00. 相似文献
882.
W. E. Jackson H. C. Wohlers W. DeCoursey 《Journal of the Air & Waste Management Association (1995)》2013,63(12):917-923
A general procedure has been described that can be followed for estimating the cost of reducing air pollution emissions within a metropolitan region. The six step procedure examines emission inventories, regional trends, control trends, alternate control schemes, control costs, and optimum cost-effectiveness. The procedure is illustrated for one emission source in the Delaware Valley. By application of “feasible controls,” automobile emissions were shown to be reduced from 4.5 billion pounds per year in the Region during 1968 to 1.5 billion pounds in the year 2000. Annual control costs during the same period will increase from $30 million to over $300 million per year. This represents a cost increase from $15 per registered vehicle in 1968 to about $58 per vehicle per year in 2000. A method was illustrated for determining minimum cost to achieve any desired degree of emission reduction where alternate feasible control schemes are available. This method is especially useful where the allocation of scarce resources is involved. The general procedure is applicable to any number of pollutants and emission sources, and may be useful for calculations in any metropolitan area. The objectives of the present study are to apply this method to other sources within the Delaware Valley and to determine total regional costs for various levels of emission reduction. As one example of a practical application for this type of analysis, the economic impact of regulatory schemes can be evaluated on a cost-effectiveness basis 相似文献
883.
LINDA LAIKRE MIJA JANSSON FRED W. ALLENDORF SVEN JAKOBSSON NILS RYMAN 《Conservation biology》2013,27(2):248-253
The wolf (Canis lupus) is classified as endangered in Sweden by the Swedish Species Information Centre, which is the official authority for threat classification. The present population, which was founded in the early 1980s, descends from 5 individuals. It is isolated and highly inbred, and on average individuals are more related than siblings. Hunts have been used by Swedish authorities during 2010 and 2011 to reduce the population size to its upper tolerable level of 210 wolves. European Union (EU) biodiversity legislation requires all member states to promote a concept called “favourable conservation status” (FCS) for a series of species including the wolf. Swedish national policy stipulates maintenance of viable populations with sufficient levels of genetic variation of all naturally occurring species. Hunting to reduce wolf numbers in Sweden is currently not in line with national and EU policy agreements and will make genetically based FCS criteria less achievable for this species. We suggest that to reach FCS for the wolf in Sweden the following criteria need to be met: (1) a well‐connected, large, subdivided wolf population over Scandinavia, Finland, and the Russian Karelia‐Kola region should be reestablished, (2) genetically effective size (Ne) of this population is in the minimum range of Ne = 500–1000, (3) Sweden harbors a part of this total population that substantially contributes to the total Ne and that is large enough to not be classified as threatened genetically or according to IUCN criteria, and (4) average inbreeding levels in the Swedish population are <0.1. Efectos de la Cacería sobre el Estatus de Conservación Favorable de Lobos Suecos con Endogamia Alta 相似文献
884.
Colin Scott Steve E. Lewis Rob Milla Matthew C. Taylor Andrew J.W. Rodgers Geoff Dumsday Jon E. Brodie John G. Oakeshott Robyn J. Russell 《Journal of environmental management》2010,91(10):2075-2078
Herbicide contamination from agriculture is a major issue worldwide, and has been identified as a threat to freshwater and marine environments in the Great Barrier Reef World Heritage Area in Australia. The triazine herbicides are of particular concern because of potential adverse effects, both on photosynthetic organisms and upon vertebrate development. To date a number of bioremediation strategies have been proposed for triazine herbicides, but are unlikely to be implemented due to their reliance upon the release of genetically modified organisms. We propose an alternative strategy using a free-enzyme bioremediant, which is unconstrained by the issues surrounding the use of live organisms. Here we report an initial field trial with an enzyme-based product, demonstrating that the technology is technically capable of remediating water bodies contaminated with the most common triazine herbicide, atrazine. 相似文献
885.
Daniel W. Franks Graeme D. Ruxton Richard James 《Behavioral ecology and sociobiology》2010,64(3):493-503
Ecologists increasingly use network theory to examine animal association patterns. The gambit of the group (GoG) is a simple
and useful assumption for accumulating the data necessary for a network analysis. The gambit of the group implies that each
animal in a group is associating with every other individual in that group. Sampling is an important issue for networks in
wild populations collected assuming GoG. Due to time, effort, and resource constraints and the difficulty of tracking animals,
sampled data are usually a subset of the actual network. Ecologists often use association indexes to calculate the frequency
of associations between individuals. These indexes are often transformed by applying a filter to produce a binary network.
We explore GoG sampling using model networks. We examine assortment at the level of the group by a single dichotomous trait,
along with many other network measures, to examine the effect of different sampling regimes, and choice of filter on the accuracy
and precision with which measures are estimated. We find strong support for the use of weighted, rather than filtered, network
measures and show that different filters have different effects depending on the nature of the sampling. We make several practical
recommendations for ecologists planning GoG sampling. 相似文献
886.
887.
Rivelino M. Cavalcante Francisco W. Sousa Ronaldo F. Nascimento Edilberto R. Silveira George S.S. Freire 《Journal of environmental management》2009,90(2):328-335
This investigation represents the first environmental diagnosis of the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments from a tropical mangrove in Fortaleza, northeastern Brazil. Sediment cores from six sampling stations in the Cocó and Ceará Rivers were retrieved in June-July 2006 to determine 17 priority PAHs. The total PAH concentrations (ΣPAHs) ranged from 3.04 to 2234.76 μg kg?1(Cocó River) and from 3.34 to 1859.21 μg kg?1 (Ceará River). These levels are higher than those of other cities with more industrial development. PAH concentrations did not reach probable effect levels (PELs). However, from 4.5 to 87.5% of individual PAH concentrations can occasionally cause adverse biological effects for aquatic organisms. The PAH molecular ratios indicate that the PAHs in the sediment core were derived mainly from petroleum, wood, and charcoal combustion (pyrogenic source), and that atmospheric deposition and urban runoff may serve as important pathways for PAH input to the sediment. Clearly, the ΣPAHs in sediments collected in the Cocó and Ceará Rivers indicate that ongoing pollution is more severe than past pollution. 相似文献
888.
The extent to which genetic divergence can occur in the absence of physical barriers to gene flow is currently one of the
most controversial topics in evolutionary biology, with implications for our understanding of speciation, phenotypic plasticity
and adaptive potential. This is illustrated by a recent study reporting a surprising pattern of genetic differentiation between
intertidal and subtidal morphotypes of the broadcast-spawning Antarctic limpet Nacella concinna. To explore this further, we collected almost 400 Antarctic limpets from four depths (intertidal, 6, 15 and 25 m) at Adelaide
island, Antarctica, and conducted a combined morphometric and genetic analysis using 168 polymorphic amplified fragment length
polymorphism (AFLP) loci. Morphological analysis revealed not only pronounced differences between the two morphotypes, but
also a continuous cline in shell shape from the intertidal zone down to 25 m depth, suggesting that the distinction between
the morphotypes may be artificial. Moreover, genetic analysis using both F
st and a Bayesian analogue found no evidence for differentiation either between the two morphotypes or by depth, and a Bayesian
cluster analysis did not detect any cryptic genetic structure. Our findings lend support to the notion that limpets can be
phenotypically highly plastic, although further studies are required to determine unequivocally whether there is any genetic
basis to the observed variation in shell morphology. 相似文献
889.
890.
Large (>90%) for gestational age (LGA) fetuses are usually identified incidentally. Detection of the LGA fetus should first prompt the provider to rule out incorrect dates and maternal diabetes. Once this is done, consideration should be given to certain overgrowth syndromes, especially if anomalies are present. The overgrowth syndromes have significant clinical and molecular overlap, and are associated with developmental delay, tumors, and other anomalies. Although genetic causes of overgrowth are considered postnatally, they are infrequently diagnosed prenatally. Here, we review prenatal sonographic findings in fetal overgrowth syndromes, including Pallister-Killian, Beckwith-Wiedemann, Sotos, Perlman, and Simpson-Golabi-Behmel. We also discuss prenatal diagnosis options and recurrence risks. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献