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111.
Two fetuses at risk for glucose-6-phosphatase deficiency had in utero liver biopsies. Analysis of each showed this enzyme activity to be in the normal range and the pregnancies continued. Neither child has any clinical or metabolic evidence of glucose-6-phosphatase deficiency.  相似文献   
112.
Globally, norovirus is the most common gastroenteritis causing pathogen. Annually, norovirus causes 685 million cases of acute gastroenteritis and 200,000  相似文献   
113.
Abstract: We used spatial and statistical analyses to identify and prioritize broad areas for conservation attention in the northern Zululand region of KwaZulu-Natal, South Africa. We attempted to identify conservation-worthy areas based on species, vegetation types, ecological processes, and threats to biodiversity. Information on species was limited and so could not form the basis of the analysis. Priority vegetation types were identified by degree of endemicity, extent of protection and transformation, and degree of fragmentation. These priority vegetation types and threats to biodiversity were used to define broad linkages between existing protected areas. We set a goal of 10% protection for each vegetation type and 25% for each species. We identified several important (endemic or threatened) animal species and predicted their ranges using a simple model. Species ranges and their hotspots were compared with the distribution of protected areas and the suggested linkages to evaluate increased species representation. Generally, the eastern part of the study area was well protected. Unprotected conservation-worthy areas under greatest threat lay in the west, and protecting these areas is a priority. Furthermore, several vegetation types were not protected by provincial authorities, a situation that also needs to be addressed. The findings of our study need to be reassessed at a finer land-parcel scale, and implementation of a range of land-use options considered.  相似文献   
114.
This note examines the efficiency of giving the victim of an externality the revenue raised by a tax on the injurer when the injurer and victim bargain with each other and act strategically. If the government has full information about the externality problem, then compensation is compatible with, but is not required for, the attainment of efficiency. If the government has limited information, then the desirability of compensation depends on the parties' behavior. In general, there is not an a priori case against compensation.  相似文献   
115.
Vegetation regeneration in post-fire environments varies across the landscape of a burned area. Variations are caused by interacting factors, including soil properties, vegetation characteristics, hydrology, land management history, and burn severity. While many of these factors have been explored previously, few studies have investigated the combination of multiple factors. A time-series of the remotely sensed enhanced vegetation index data has been analyzed to estimate rates of regeneration across a burn in central Arizona. We used regression trees to evaluate post-fire vegetation response as a function of multiple factors. Regeneration was a function of elevation (likely a proxy for moisture availability), burn severity, pre-burn vegetation, and post-burn management activities. Both time-series vegetation data and regression trees were valuable tools for determining dominant interacting factors responsible for variations in post-fire regeneration. Evaluation of the time-series data and modeled post-fire vegetation permitted the interpretation of management actions across the burned area.  相似文献   
116.
The impact of diverse composition in teams is neither straightforward nor direct, and evidence suggests that diversity can be either conducive or detrimental to team innovation. Professionally diverse healthcare teams are increasingly used to develop innovative clinical approaches and solve complex healthcare problems; however, there is evidence that collaboration across professional boundaries creates conflict and is frequently unsuccessful. Healthcare organizations consequently face a dilemma. If they embrace professional diversity in teams, they risk interprofessional hostility, but if they choose homogeneous teams, they diminish their teams' capacity to innovate. We respond to this quandary by utilizing social identity theory to better understand the mechanisms through which professional diversity can enhance team innovation. In particular, we argue that professional identity salience operates as a mediator capable of explaining both positive and negative outcomes of professional diversity, contingent on the moderating effect of openmindedness norms. Analysis of survey data from 70 healthcare teams supports our model and indicates that professional salience can both enhance and undermine team innovation, depending on the extent of team openmindedness. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
117.
Ainley DG  Ballard G  Dugger KM 《Ecology》2006,87(8):2080-2093
An apparent trophic cascade that appears during summer in the western Ross Sea, Antarctica, explains why the Antarctic silverfish (Pleuragramma antarcticum) there becomes cannibalistic; its principal prey, crystal krill (Euphausia crystallorophias) becomes scarce; and the diatom community is minimally grazed compared to adjacent areas. The krill is the major grazer of diatoms. On the basis of fieldwork at Ross Island, we suggest that the cascade results from foraging by unusually numerous Adélie Penguins (Pygoscelis adeliae), minke whales (Balaenoptera bonaerensis), and fish-eating killer whales (Orcinus orca). These species and other top predators apparently deplete the krill and silverfish. In drawing our conclusions, we were aided by two "natural experiments." In one "experiment," large, grounded icebergs altered the seasonal pattern of change in regional sea-ice cover, but not the seasonal change in penguin diet and foraging behavior that was also detected during the pre-iceberg era. In the other "experiment," a short-term polynya (opening in the ice) brought penguins and whales together in a confined area, this time altering both penguin diet and foraging behavior. We conclude that the foraging of penguins and whales, and not a formerly hypothesized seasonal decrease in sea-ice cover, explains (1) the annual switch in the penguins' prey from krill to silverfish, (2) the subsequent lengthening of penguin foraging trips, and (3) a marked decline of cetaceans in the area later in the season. Reduction in the middle-trophic-level prey is expressed in the relaxed grazing pressure on phytoplankton.  相似文献   
118.
Ontogenetic variation in plasticity is important to understanding mechanisms and patterns of thermal tolerance variation. The Bogert effect postulates that, to compensate for their inability to behaviourally thermoregulate, less-mobile life stages of ectotherms are expected to show greater plasticity of thermal tolerance than more-mobile life stages. We test this general prediction by comparing plasticity of thermal tolerance (rapid cold-hardening, RCH) between mobile adults and less-mobile larvae of 16 Drosophila species. We find an RCH response in adults of 13 species but only in larvae of four species. Thus, the Bogert effect is not as widespread as expected.  相似文献   
119.
Global increases in ultraviolet‐B radiation (UVBR) associated with stratospheric ozone depletion are potentially contributing to the decline of numerous amphibian species around the world. Exposure to UVBR alone reduces survival and induces a range of sublethal effects in embryonic and larval amphibians. When additional environmental stressors are present, UVBR can have compounding negative effects. Thus, examination of the effects of UVBR in the absence of other stressors may substantially underestimate its potential to affect amphibians in natural habitats. We examined the independent and interactive effects of increased UVBR and high conspecific density would have embryonic and larval striped marsh frogs (Limnodynastes peronii). We exposed individuals to a factorial combination of low and high UVBR levels and low, medium, and high densities of striped marsh frog tadpoles. The response variables were time to hatching, hatching success, posthatch survival, burst‐swimming performance of tadpoles (maximum instantaneous swim speed following an escape response), and size and morphology of tadpoles. Consistent with results of previous studies, we found that exposure to UVBR alone increased the time to hatching of embryos and reduced the burst‐swimming performance and size of tadpoles. Similarly, increasing conspecific density increased the time to hatching of embryos and reduced the size of tadpoles, but had no effect on burst‐swimming performance. The negative effect of UVBR on tadpole size was not apparent at high densities of tadpoles. This result suggests that tadpoles living at higher densities may invest relatively less energy in growth and thus have more energy to repair UVBR‐induced damage. Lower densities of conspecifics increased the negative effects of UVBR on developing amphibians. Thus, low‐density populations, which may include declining populations, may be particularly susceptible to the detrimental effects of increased UVBR and thus may be driven toward extinction faster than might be expected on the basis of results from single‐factor studies. Relaciones entre la Densidad Conespecífica y los Efectos de la Radiación Ultravioleta‐B sobre el Tamaño de Renacuajos de Limnodynastes peronei  相似文献   
120.
Integrated catchment management (ICM) was introduced as state policy in 1988 to overcome land and water degradation in Western Australia (WA). Key elements of ICM are cooperation among state and local governments and landholders; involvement of landholders and local communities in identification of issues and solutions; and, agreement on common objectives. This study identifies the issues that led to the adoption of integrated catchment management in Western Australia, outlines its main characteristics, and reviews the progress and problems encountered during its initial implementation. ICM has generally been accepted and endorsed in WA. However, differences of opinion have emerged regarding exactly what it means and how it should be applied. Designing ideal organizational structures for ICM is not sufficient for it to be effective. Ultimately, people have to make ICM function, and therefore it is essential that priority be given to cultivating the good will and trust necessary for ICM to work well. ICM also requires a long-term perspective and appreciation that it requires many people and agencies to move out of current “comfort zones.” As a result, initial implementation of ICM usually will encounter turbulence and debate.  相似文献   
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