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711.
BACKGROUND: Seventeen states enacted graduated driver licensing (GDL) programs that were implemented from 1996 through 1999 and for which evaluations are of interest. METHODS: We received evaluation results reported for six states for which data were available. Summarizing results is difficult in other than the most global terms because of differences in pre-GDL programs, differences in GDL programs, and differences in evaluation methodology. RESULTS: All states identified some crash reduction among teen drivers following GDL implementation. This positive effect was observed across different geographic regions, and with different GDL programs. Simple counts are down-fewer teens are experiencing crashes and becoming injured. After calculating crash rates to adjust for changes over time in populations or licensed drivers, reductions generally were still found. Population-adjusted risks of injury/fatal crash involvement of 16-year-old drivers in Florida and Michigan were reduced by 11% and 24%, respectively. Population-adjusted risks of any crash involvement of 16-year-old drivers in Michigan and North Carolina were reduced by 25% and 27%, respectively. Reductions in night (restricted hours) crash risk were impressive in Florida, Michigan, and North Carolina. A comparison state design was only possible in the Florida evaluation, and results showed greater crash reductions under GDL. Change-point analyses of Michigan's crash data trends over time provided additional support of GDL's effectiveness in reducing crashes. DISCUSSION: Taken as a whole, and including the preliminary findings from California, Ohio, and Pennsylvania, these reports demonstrate the early effectiveness of GDL in reducing the crash risk of teen drivers. The impact of these studies and others to come will guide future research, practice, and policy.  相似文献   
712.
Mussels, coming from an aquaculture farm located in a clean open bay, were transplanted to several stations of the bays of Nice and Cannes (NW Mediterranean) including a reference site for one month at three periods. Several biomarkers: activities of glutathione S-transferase (GST; exposure to organics), of catalase (exposure to oxidative stress) and of acetylcholinesterase (inhibited by some pesticides) and the lipid peroxidation (thiobarbituric acid reactive substances: TBARS) were measured in transplanted mussels. Cd, Cu and Zn concentrations were also measured as well as their condition index. The results demonstrated some seasonal variations in GST and catalase activities with higher levels in June compared to October. The condition index was also higher in June than in October. Principal component analyses performed with the whole set of data allowed to separate stations or groups of stations according to their responses. The mussels from the harbour of Nice were characterized by high TBARS levels and catalase activity in October 1999 whereas in the harbour of Cannes, animals presented very high copper concentrations and GST activities in June 2000. At the reference site, mussels generally presented low enzymatic activities (except AChE activity) and peroxidation levels and low heavy metal concentrations.  相似文献   
713.
714.
The detection of very rare variants in prenatal diagnosis often causes counseling difficulties and anxiety in parents. We describe a duplication of the proximal region of chromosome 9 short arm in two cases of prenatal diagnosis and in one young woman, with evidence that such rearrangement is an uncommon variant. The duplication was investigated using Fluorescence in situ hybridization (FISH). Although the cytogenetic findings were indicative of a ‘duplication 9p syndrome’ associated with mental and developmental retardation, we were able to demonstrate that the rearrangement was a heteromorphism with no phenotypic consequence. We also determined the breakpoint regions of the rearrangement and identified the BAC probes that precisely define the duplicated region devoid of risk of phenotypic effects. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献   
715.
Head neck and back injury represents 32% of injuries in the NSW coal mining industry. There is considerable hearsay evidence that rough rides in vehicles are a significant cause of such injuries but no objective studies have been carried out.Analysis of workers compensation data showed that overexertion and slips and falls were the most significant causes of head neck and back injuries but approximately 11% of all head neck and back injuries were reported to be due to vehicle jarring. Two types of underground vehicles accounted for 53% of all injuries. These were Shuttlecars and Underground Transporters.There was no evidence from the compensation data that whole body vibration was a significant factor in head neck and back injuries.  相似文献   
716.
Bioassays of diesel engine exhaust components are being conducted at IITRI to determine toxic and carcinogenic potentials of the exhaust. The bioassay method, intracheal instillation of saline suspensions of test materials in hamsters, requires preparation of stable suspensions of test materials. A method to prepare suspensions of whole particle diesel exhaust in saline has been developed. The diesel exhaust particle material was supplied to IITRI as a dry, loose powder by the U.S. EPA from a light duty diesel test engine. Preliminary characterizations of the powders indicated aggregation of exhaust particles had occurred both before and during capture on collection substrates. Flake-like sheets and hollow spheres of aggregated particles up to 150 μm in sie present in the powders. Therefore, the powder were ball-milled to geometric particle sizes more amenable to the animal administration technique to be employed. Grinding, suspension preparation and particle concentration assaying methods have been developed. Particle (geometric) size and morphological characterizations have also been performed on the as-received powders and prepared suspensions. A method to prepare emulsions (liquid-liquid suspensions) of the dichloromethane extracts of whole particle diesel exhaust has also been developed.  相似文献   
717.
Rockfishes of the genus Sebastes are extensively distributed in the Pacific and Atlantic oceans. Although the occurrence of two morphologically similar species in the Southern Hemisphere, Sebastes oculatus and Sebastes capensis, is now clearly established, the taxonomic status and phylogeographic patterns for the genus in the region have not yet been completely resolved. In this study, we provide new insights into the taxonomy and evolutionary relationships of rockfishes inhabiting the Southwestern Atlantic Ocean, off the coast of mainland Argentina, by combining mitochondrial DNA (mtDNA) control region sequences, microsatellite data, and color pattern analyses. Differences in coloration (“dark” and “light” fish) together with bathymetric segregation between color morphotypes were evident from fish collection and literature review. In addition, the mtDNA phylogenetic analysis and Bayesian clustering analysis using microsatellite data separated the fish into two distinct groups (F ST?=?0.041), most likely representing incipient species. Our results suggest that speciation-by-depth in the absence of physical barriers could be a widespread mechanism of speciation in Sebastes from both the Northern and Southern Hemispheres. Nevertheless, the degree of genetic differentiation found, added to the large number of individuals displaying high levels of admixture, points to the occurrence of incomplete reproductive barriers between color morphotypes. Beyond the taxonomic and phylogeographic implications of our findings, the occurrence of distinct groups of Sebastes off the coast of Argentina being targeted by different fisheries (angling and trawling) has consequences for the design and implementation of appropriate fishery regulations to avoid overharvest of either group.  相似文献   
718.
Bird abundance was assessed on a total of 58 farms across the Seine-et-Marne department, France (12 organic, 19 conservation-tillage and 27 conventional farms). Local abundance variations among the three farming systems were related to two species traits, i.e. habitat specialisation and diet, considering both farmland and non-farmland species. It was found that organic farming favoured specialist birds, either considering the whole community or non-farmland birds only. On the opposite, specialist farmland species were found to be less abundant in conservation-tillage farms than in conventional ones. Invertebrate-feeders were found to benefit from conservation-tillage practices compared to omnivorous species but not compared to granivorous ones; an interaction between species diet and the species specialisation level was also found. Granivorous species tended to increase with the conservation-tillage duration and in particular specialist birds.  相似文献   
719.
INTRODUCTION: This article examines five major road-safety risk factors: exceeding posted speed limits, not using safety belts, driving while intoxicated, nighttime driving, and young drivers. METHOD: The importance of each of these factors is documented, known effective countermeasures (both policy and technology based) are discussed, and impediments to the implementation of these countermeasures in the United States are examined. RESULTS: Based on current understanding of the five major risk factors, and of the available countermeasures, there appear to be a variety of opportunities to make substantial gains in road safety using existing knowledge. The limited implementation of a variety of known countermeasures therefore appears to be inconsistent with high-level, strategic goals to improve road safety. Consequently, a recommendation is made to comprehensively re-examine the balance between the countermeasures discussed in this article and economic, mobility, and privacy concerns. IMPACT ON PUBLIC SAFETY: Such a re-examination is likely to result in broad support for these countermeasures, with a consequent major improvement in road safety.  相似文献   
720.
Four sites were selected in a salt marsh in the Bah′?a Blanca Estuary (Argentina): (1) low marsh (flooded by the tide twice daily) vegetated by S. alterniflora; (2) non-vegetated low marsh; (3) high marsh (flooded only in spring tides) vegetated by S. alterniflora; (4) non-vegetated high marsh. The pH and Eh were measured in sediments, while dissolved nutrients (ammonium, nitrate, nitrite and phosphate) and particulate organic matter (POM) were determined in pore water. pH (6.2–8.7) was only a ected by vegetation in low areas. Eh (from –300 to 250 mV) was lower at low sites than at high ones; in the latter, the values were higher in the non-vegetated sediments. The POM concentration was greater in the high marsh than in the low marsh, with no e ect of vegetation. Ammonium was the most abundant nitrogen nutrient species in pore water, except in the non-vegetated high marsh where nitrate concentration was higher. All nitrogen nutrients were a ected by both flooding and vegetation. Phosphate was always present in pore water at all sites throughout the year and its concentration varied within narrow limits, with no e ect of flooding and greater values always at non-vegetated sites. Our results showed that the variability of the pore water composition within the marsh is greater than the temporal variation, meaning that both tidal flooding and vegetation are important in the dynamics of nutrients and organic matter in the sediment pore water.  相似文献   
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