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931.
Marco Antonio Leonel Caetano Douglas Francisco Marcolino Gherardi Gustavo de Paula Ribeiro Takashi Yoneyama 《Ecological modelling》2009,220(19):2536-2542
The recent global financial crisis has highlighted the need for balanced and efficient investments in the reduction of the greenhouse effect caused by emissions of CO2 on a global scale. In a previous paper, the authors proposed a mathematical model describing the dynamic relation of CO2 emission with investment in reforestation and clean technology. An efficient allocation of resources to reduce the greenhouse effect has also been proposed. Here, this model is used to provide estimates of the investments needed in land reforestation and in the adoption of clean technologies for an optimum emission and abatement of CO2, for the period of 1996–2014. The required investments are computed to minimize deviations with respect to the emission targets proposed in the Kyoto Protocol for European Countries. The emission target can be achieved by 2014 with investments in reforestation peaking in 2004, and a reduction of the expected GDP of 42%, relative to 2006. Investments in clean technology should increase between 2008 and 2010 with maximum transfer figures around 70 million American dollars. Total (cumulative) costs are, however, relatively high depending on the price of carbon abatement and the rate at which the expected CO2 concentration in the atmosphere should be reduced. Results highlight the advantages for policy makers to be able to manage investments in climate policy more efficiently, controlling optimum transfers based on a portfolio of actions that tracks a pre-defined CO2 concentration target. 相似文献
932.
Pius Lee Youhua Tang Daiwen Kang Jeff McQueen Marina Tsidulko Ho-Chun Huang Sarah Lu Mary Hart Hsin-Mu Lin Shaocai Yu Geoff DiMego Ivanka Stajner Paula Davidson 《Environmental Fluid Mechanics》2009,9(1):23-42
Discrepancies in grid structure, dynamics and physics packages in the offline coupled NWS/NCEP NAM meteorological model with
the U.S. Environmental Protection Agency Community Multiscale Air Quality (CMAQ) model can give rise to inconsistencies. This
study investigates the use of three vertical mixing schemes to drive chemistry tracers in the National Air Quality Forecast
Capability (NAQFC). The three schemes evaluated in this study represent various degrees of coupling to improve the commonality
in turbulence parameterization between the meteorological and chemistry models. The methods tested include: (1) using NAM
predicted TKE-based planetary boundary height, h, as the prime parameter to derive CMAQ vertical diffusivity; (2) using the NAM mixed layer depth to determine h and then proceeding as in (1); and (3) using NAM predicted vertical diffusivity directly to parameterize turbulence mixing
within CMAQ. A two week period with elevated surface O3 concentrations during the summer 2006 has been selected to test these schemes in a sensitivity study. The study results are
verified and evaluated using the EPA AIRNow monitoring network and other ozonesonde data. The third method is preferred a
priori as it represents the tightest coupling option studied in this work for turbulent mixing processes between the meteorological
and air quality models. It was found to accurately reproduce the upper bounds of turbulent mixing and provide the best agreement
between predicted h and ozonesonde observed relative humidity profile inferred h for sites investigated in this study. However, this did not translate into the best agreement in surface O3 concentrations. Overall verification results during the test period of two weeks in August 2006, did not show superiority
of this method over the other 2 methods in all regions of the continental U.S. Further efforts in model improvement for the
parameterizations of turbulent mixing and other surface O3 forecast related processes are warranted. 相似文献
933.
Youhua Tang Pius Lee Marina Tsidulko Ho-Chun Huang Jeffery T. McQueen Geoffrey J. DiMego Louisa K. Emmons Robert B. Pierce Anne M. Thompson Hsin-Mu Lin Daiwen Kang Daniel Tong Shaocai Yu Rohit Mathur Jonathan E. Pleim Tanya L. Otte George Pouliot Jeffrey O. Young Kenneth L. Schere Paula M. Davidson Ivanka Stajner 《Environmental Fluid Mechanics》2009,9(1):43-58
A sensitivity study is performed to examine the impact of lateral boundary conditions (LBCs) on the NOAA-EPA operational Air
Quality Forecast Guidance over continental USA. We examined six LBCS: the fixed profile LBC, three global LBCs, and two ozonesonde
LBCs for summer 2006. The simulated results from these six runs are compared to IONS ozonesonde and surface ozone measurements
from August 1 to 5, 2006. The choice of LBCs can affect the ozone prediction throughout the domain, and mainly influence the
predictions in upper altitude or near inflow boundaries, such as the US west coast and the northern border. Statistical results
shows that the use of global model predictions for LBCs could improve the correlation coefficients of surface ozone prediction
over the US west coast, but could also increase the ozone mean bias in most regions of the domain depending on global models.
In this study, the use of the MOZART (Model for Ozone And Related chemical Tracers) prediction for CMAQ (Community Multiscale
Air Quality) LBC shows a better surface ozone prediction than that with fixed LBC, especially over the US west coast. The
LBCs derived from ozonesonde measurements yielded better O3 correlations in the upper troposphere. 相似文献
934.
Sophie Plumejeaud Amelia Paula Reis Virginie Tassistro Carla Patinha Yves Noack Thierry Orsière 《Environmental geochemistry and health》2018,40(1):127-144
Due to their behavioral characteristics, young children are vulnerable to the ingestion of indoor dust, often contaminated with chemicals that are potentially harmful. Exposure to potentially harmful elements (PHEs) is currently exacerbated by their widespread use in several industrial, agricultural, domestic and technological applications. PHEs cause adverse health effects on immune and nervous systems and can lead to cancer development via genotoxic mechanisms. The present study is an integrated approach that aims at assessing the genotoxicity of bioaccessible PHEs following ingestion of contaminated house dust. A multidisciplinary methodology associating chemical characterization of five house dust samples, extraction of the bioaccessible PHEs in gastric extracts by the unified BARGE method, determination of the bioaccessible fraction and in vitro genotoxicity of gastric extracts in adenocarcinoma gastric human (AGS) cells was developed. The five gastric extracts induced dose-dependent genotoxicity in AGS cells. Copper (bioaccessible concentration up to 111 mg/kg) was probably the prevalent PHE inducing primary DNA damage (up to 5.1-fold increase in tail DNA at 0.53 g/l of gastric extract). Lead (bioaccessible concentration up to 245 mg/kg) was the most prevalent PHE inducing chromosome-damaging effects (r = 0.55; p < 0.001 for micronucleated cells induction). The association of principal component analysis and Spearman’s correlations was decisive to understand the chromosome-damaging properties of the bioaccessible PHEs in AGS cells. This methodology could be used on a larger-scale study to provide useful information for science-based decision-making in regulatory policies, and a better estimation of human exposure and associated health risks. 相似文献
935.
Phylogeographic patterns in Uca annulipes sampled from 30 locations across an East African latitudinal gradient were investigated using mitochondrial DNA cytochrome
oxidase I sequences and analysed together with patterns of morphometric differentiation. Four hundred and four specimens along
the east African coast were sampled, and 18 haplotypes were encountered. Haplotype and nucleotide diversity values were very
low and the phylogenetic analysis did not reveal any clear phylogeographic structure. Furthermore, the analysis of molecular
variance and pairwise Φ
ST values showed no significant spatial population differentiation. Mismatch analyses and tests of neutrality supported the
hypothesis that this species has undergone a fairly recent demographic expansion. Our results, therefore, failed to demonstrate
significant geographical structure in the pattern of genetic variation, indicating that populations of U. annulipes are capable of extensive gene flow among mangroves along the coast. The genetic structure of this species could be panmictic
due to a high amount of gene flow along the geographical gradient in study during the planktonic larval phase, when larvae
are carried along stream by the dominant currents. Moreover, the morphometric analysis performed did not reveal differences
of shape differentiation according to a geographical pattern, although significant differences among the sampling areas were
found. 相似文献
936.
Hudson Wallace Pereira Carvalho Ana P. L. Batista Peter Hammer Gustavo H. P. Luz Teodorico C. Ramalho 《Environmental Chemistry Letters》2010,8(4):343-348
Polysaccharide natural seed coat from the tree Magonia pubescens, in the form of hydrogel was used to remove metals in aqueous solution. Swelling tests indicate that seed coat presents hydrogel
behavior, with maximum water absorption of 292 g water/g. Adsorption experiments performed using Na+, Mg2+, K+, Ca2+, Cr3+, Fe3+ and Zn2+ demonstrated that the polysaccharide structure has a high capacity to extract these ions from the aqueous solution. Scanning
electron microscopy revealed significant morphological changes of the material before and after water contact. Differential
scanning calorimetry measurements indicate a signal shift of the water evaporation temperature in the material with adsorbed
zinc. X-ray photoelectron spectroscopy analysis combined with theoretical studies by the density functional theory and on
Hartree–Fock (HF) level evidence that the metallic ions were adsorbed through coordination with hydroxyl groups of polysaccharide.
In the case of Zn2+ the lowest HF energy was observed for the tetracoordination mode, where Zn2+ is coordinated by two hydroxyl groups and two water molecules. 相似文献
937.
The growth pattern of Loxechinus albus in southern Chile was studied using size-at-age data obtained by reading growth bands on the genital plates. The scatter
plots of sizes-at-age for samples collected in three different locations indicated that growth is linear between ages 2 and
10. Five different growth models, including linear, asymptotic and non-asymptotic functions, were fitted to the data, and
model selection was conducted based on the Akaike information criteria (AIC) and the Bayesian information criteria (BIC).
The AIC identified the Tanaka model as the most suitable for two of the three sites. However, the BIC led to the selection
of the linear model for all zones. Our results show that the growth pattern of L. albus is different from the predominantly asymptotic pattern that has been reported for other sea urchin species. 相似文献
938.
Sofia Gamito Paula Chainho João Paulo Medeiros João Carlos Marques 《Ecological modelling》2010,221(3):459-466
The brackish water amphipod Corophium orientale is the dominant macroinvertebrate species in the upper Mira estuary, a small mesotidal system located in the southwest coast of Portugal. As climate changes will increase the frequency and intensity of extreme events such as floods and droughts, these will have a negative effect on benthic estuarine invertebrates, namely C. orientale. In order to understand the effects of these events on C. orientale, a dynamic model, based on published information and calibrated with field data, was developed and different scenarios were tested.For model construction, the annual development of three cohorts of C. orientale, their growth rates, and the establishment of the timing of each cohort rise and extinction are introduced. This structure can be repeated indefinitely, for years, and few parameters are required. The model simulations highlight the need for refuge areas that enable a fast recovery of the amphipod population after an extreme event and the recolozination of the affected areas. 相似文献
939.
With the discovery of previously unreported populations of hemoglobin-possessing Ophiactis from the Texas coast in the Gulf of Mexico, an investigation into its population structure, including populations of O. simplex from the Pacific coast of California and O. rubropoda from the Atlantic coast of Florida, was undertaken using DNA sequence data from the mitochondrial COI gene. The reconstructed
haplotype network suggests that California populations contain the ancestral source of mtDNA variation, and there is no evidence
of recent introductions into Texas. Population genetic analyses reveal the California, Florida, and Texas Ophiactis populations to each be significantly differentiated from one another. Sequence divergence among the three areas is shallower
than would be predicted given biogeographic history. Texas and Florida populations are equally genetically diverged from California
populations as they are to one another, despite the greater potential for gene flow between these areas. The genetic distinctiveness
of the Texas populations and the concordance of this pattern with phylogeographic patterns in other brittle star systems indicate
an isolated and independent evolutionary history and we hypothesize that the three geographic regions included in this study
each serve as hypotheses of population-level lineages that remain to be tested with independent sources of data. 相似文献
940.
Paula A. White 《Behavioral ecology and sociobiology》2008,62(3):377-361
Among spotted hyenas, Crocuta crocuta, neonatal aggression in twins is a well-known phenomenon and serves to establish intra-litter dominance soon after birth.
As the stronger more aggressive cub presumably attains dominance over its twin, intra-litter dominance presents mothers with
an ideal opportunity to assess individual cub fitness and, thereafter, to selectively favor one cub over the other. This study
quantified maternal response to sibling conflict in 26 sets of twins born to 16 wild-living females to determine whether mothers
of different social ranks exhibited favoritism towards sons or daughters, or in the case of same-sex twins, the dominant or
subordinate cub. Maternal response to sibling conflict did not vary with litter sex composition, suggesting that mothers do
not favor offspring of one sex over the other. All mothers intervened when their cubs fought and sometimes punished their
cubs. Higher-ranking mothers more often punished both cubs, while lower-ranking mothers were more selective and punished the
dominant cub. Where sibling aggression was most extreme, rather than favor the dominant sibling, mothers of all ranks made
concessions to the subordinate cub that included procuring private nursing bouts for the subordinate and temporarily housing
twins in separate dens, presumably to decrease sibling conflict. These findings represent a complex example of parent–offspring
conflict and support both the insurance cub hypothesis and resource tracking hypothesis that mothers endeavor to keep all
offspring alive for as long as possible in the event that the dominant sibling dies or that resources provide for the rearing
of twins.
This contribution is part of the special issue “Sibling competition and cooperation in mammals” (guest editors: Robyn Hudson
and Fritz Trillmich). 相似文献