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151.
Kevin Shirley Eric Marland Jenna Cantrell Gregg Marland 《Mitigation and Adaptation Strategies for Global Change》2011,16(3):325-346
We recognize that carbon-containing products do not decay and release CO2 to the atmosphere instantaneously, but release that carbon over extended periods of time. For an initial production of a
stock of carbon-containing product, we can treat the release as a probability distribution covering the time over which that
release occurs. The probability distribution that models the carbon release predicts the amount of carbon that is released
as a function of time. The use of a probability distribution in accounting for the release of carbon to the atmosphere realizes
a fundamental shift from the idea that all carbon-containing products contribute to a single pool that decays in proportion
to the size of the stock. Viewing the release of carbon as a continuous probabilistic process introduces some theoretical
opportunities not available in the former paradigm by taking advantage of other fields where the use of probability distributions
has been prevalent for many decades. In particular, theories developed in the life insurance industry can guide the development
of pricing and payment structures for dealing with the costs associated with the oxidation and release of carbon. These costs
can arise from a number of proposed policies (cap and trade, carbon tax, social cost of carbon, etc), but in the end they
all result in there being a cost to releasing carbon to the atmosphere. If there is a cost to the emitter for CO2 emissions, payment for that cost will depend on both when the emissions actually occur and how payment is made. Here we outline
some of the pricing and payment structures that are possible which result from analogous theories in the life insurance industry.
This development not only provides useful constructs for valuing sequestered carbon, but highlights additional motivations
for employing a probability distribution approach to unify accounting methodologies for stocks of carbon containing products. 相似文献
152.
A benthic index for northern Gulf of Mexico estuaries has been developed and successfully validated by the Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) in the Louisianian Province. The benthic index is a useful and valid indicator of estuarine condition that is intended to provide environmental managers with a simple tool for assessing the ecological condition of benthic macroinvertebrate communities. Associations between the benthic index and indicators of hypoxia, sediment contamination, and sediment toxicity were investigated to determine the most probable cause(s) of degraded benthic condition. The results showed that, on a local scale, the associations between the benthic index and potential environmental causes differed among estuaries. In Pensacola Bay, FL, for example, there was a significant association between the levels of toxic chemicals (e.g. DDT, silver, and TBT) in the sediment and the benthic index, especially in the bayous which have known sediment contamination problems. In Mobile Bay, however, degraded benthic communities were more closely associated with eutrophication and hypoxia. Nevertheless, a benthic index is a valuable tool for identifying areas that could be already degraded and tracking the status of environmental condition in large geographical regions. 相似文献
153.
Gary L. Ketcheson Walter F. Megahan John G. King 《Journal of the American Water Resources Association》1999,35(1):83-98
ABSTRACT: Erosion and sedimentation data from research watersheds in the Silver Creek Study Area in central Idaho were used to test the prediction of logging road erosion using the R1-R4 sediment yield model, and sediment delivery using the “BOISED” sediment yield prediction model. Three small watersheds were instrumented and monitored such that erosion from newly constructed roads and sediment delivery to the mouths of the watersheds could be measured for four years following road construction. The errors for annual surface erosion predictions for the two standard road tests ranged from +31.2 t/ha/yr (+15 percent) to -30.3 t/ha/yr (-63 percent) with an average of zero t/ha/yr and a standard deviation of the differences of 18.7 t/ha/yr. The annual prediction errors for the three watershed scale tests had a greater range from -40.8 t/ha/yr (-70 percent) to +65.3 t/ha/yr (+38 percent) with a mean of -1.9 t/ha/yr and a standard deviation of the differences of 25.2 t/ha/yr. Sediment yields predicted by BOISED (watershed scale tests) were consistently greater (average of 2.5 times) than measured sediment yields. Hillslope sediment delivery coefficients in BOISED appear to be overly conservative to account for average site conditions and road locations, and thus over-predict sediment delivery. Mass erosion predictions from BOISED appear to predict volume well (465 tonnes actual versus 710 tonnes predicted, or a 35 percent difference) over 15 to 20 years, however mass wasting is more episodic than the model predicts. 相似文献
154.
S. Lawrence Dingman Kevin J. Palaia 《Journal of the American Water Resources Association》1999,35(5):1233-1243
We develop and compare three regression models for estimating flood quantiles at ungaged stream reaches in New Hampshire and Vermont. These models emerge from systematic analysis and validation of relations between flood magnitude and six candidate predictors reflecting basin size, topography, and climate and channel size at 36 gaging stations with record lengths exceeding 20 years. Of the candidate predictors, bank full width is most highly correlated with flood magnitude and the best prediction equation is based on width. Thus channel geometry is closely related to the current hydrologic regime in spite of geologically recent glaciation and apparently non-alluvial bank materials. We also develop models that use information obtainable from maps or GIS. The best of these uses drainage area and drainage-basin elevation as predictors, but it is substantially less precise than the width-based relation. A third relation using only drainage area as a predictor is even less precise but may be useful for some purposes. No other single predictors or combinations yielded useful predictions, although some had been included in previously-established models for the region. Model comparison included examination of residuals generated by regression using one-at-a-time suppression of data points and comparison with precision obtainable with gaging records of varying lengths. 相似文献
155.
Kevin R. Foster Perttu Seppä Francis L. W. Ratnieks Peter A. Thorén 《Behavioral ecology and sociobiology》1999,46(4):252-257
Queen mating frequency was studied in the European hornet, Vespa crabro, by analyzing four DNA microsatellite loci in 20 workers from each of 14 nests. Queens were found to be predominantly singly
mated (9/14), although double (4/14) and triple mating (1/14) also occurred. For most multiply mated queens, paternity was
significantly biased with the majority male fathering on average 80% of the female offspring. The population-wide effective
mating frequency was therefore low (1.11), and sister-sister relatedness high (0.701 ± 0.023 SE). Low effective mating frequency
in Vespa, in combination with data from other vespines, suggests that high paternity frequency is derived in the group. Some problems
with the non-detection of fathers, where the queen was not sampled or shared alleles with males, are analyzed.
Received: 16 November 1998 / Received in revised form: 29 March 1999 / Accepted: 12 April 1999 相似文献
156.
The host size model, an adaptive model for maternal manipulation of offspring sex ratio, was examined for the parasitoid
wasp Spalangia endius. In a Florida strain, as the model predicts, daughters emerged from larger hosts than sons, but only when mothers received
both small and large hosts simultaneously. The pattern appeared to result from the mother's ovipositional choice and not from
differential mortality of the sexes during development. If sex ratio manipulation is adaptive in the Florida strain, it appears
to be through a benefit to daughters of developing on large hosts rather than through a benefit to sons of developing on small
hosts. Both female and male parasitoids were larger when they developed on larger hosts. For females, developing on a larger
host (1) increased offspring production, except for the largest hosts, (2) increased longevity, (3) lengthened development,
and (4) had no effect on wing loading. For males, development on a larger host had no effect on any measure of male fitness
– mating success, longevity, development duration, or wing loading. In contrast, a strain from India showed no difference
in the size of hosts from which daughters versus sons emerged, although both female and male parasitoids were larger when
they developed on larger hosts. These results together with previous studies of Spalangia reveal no consistent connection between host-size-dependent sex ratio and host-size-dependent parasitoid size among strains
of S. endius or among species of Spalangia.
Received: 28 October 1998 / Received in revised form: 20 May 1999 / Accepted: 30 May 1999 相似文献
157.
A volume of sand containing coal tar creosote was emplaced below the water table at CFB Borden to investigate natural attenuation processes for complex biodegradable mixtures. Coal tar creosote is a mixture of more than 200 polycyclic aromatic hydrocarbons, heterocyclic compounds and phenolic compounds. A representative group of seven compounds was selected for detailed study: phenol, m-xylene, naphthalene, phenanthrene, 1-methylnaphthalene, dibenzofuran and carbazole. Movement of groundwater through the source led to the development of a dissolved organic plume, which was studied over a 4-year period. Qualitative plume observations and mass balance calculations indicated two key conclusions: (1) compounds from the same source can display distinctly different patterns of plume development and (2) mass transformation was a major influence on plume behaviour for all observed compounds. 相似文献
158.
Using a multilevel framework, we hypothesized that both employee perceptions of procedural justice and a work unit level measure of procedural justice context would be associated with employee reports of job satisfaction and organizational commitment. Three hundred and twenty-three employees from 53 branches of a financial services organization were used to test this hypothesis. Hierarchical linear modeling analyses revealed that procedural justice context explained variance in employee job satisfaction beyond that accounted for by individual perceptions of procedural justice. With regard to organizational commitment, this hypothesis was not supported. The results are discussed in connection with contextual aspects of procedural justice. © 1998 John Wiley & Sons, Ltd. 相似文献
159.
160.
Julien H. Richard Kevin S. White Steeve D. Côté 《Behavioral ecology and sociobiology》2014,68(10):1639-1648
In ungulates, the rut generally leads to increased intra and interpopulation movements for males. Because movements induce energetic costs and missed feeding opportunities, they could be an indication of male mating effort. We studied space use of 44 male mountain goats (Oreamnos americanus) from three neighboring subpopulations in southeast Alaska, during the rut from 2005 to 2008. Using mixed models and an information theoretic approach with AIC, we analyzed the relationships between individual traits of males and their space use. We found no indication of breeding migration between subpopulations. Distances between individual seasonal ranges were not related to any individual trait. Daily movements, home range sizes, and total distance traveled during the rut did not vary with mass or age of individuals. As such, effects of individual traits on male space use during the rut appear weak and observed space use patterns do not support any of the main mating effort hypotheses. 相似文献