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131.
Deploying heating technologies, such as air-source heat pumps (ASHPs), can respond to the dual challenges of tackling fuel poverty and reducing carbon emissions from domestic energy consumption. In the UK, ASHP performance has been found to be below design levels. Elements of three strands of literature – innovation diffusion, environmental psychology and neighbourhood effects – are combined to gain insights into why the adoption and performance of ASHPs are lagging policy targets and design potential. Evidence from users, installers and area-based scheme facilitators suggests that the perceived complexity of the technology is a barrier. The level of technology maturity and the typical profile of the elderly fuel poor do not match; the target group might prefer to be late adopters or laggards in adopting technology. The role of installers is critical as the disruption from installation is a barrier to adoption and ASHPs place demands on users to change existing practices.  相似文献   
132.
133.
Transvaginal chorionic villus sampling (CVS) using concurrent transabdominal ultrasound guidance was performed in six women who desired CVS but could not be offered transcervical or transabdominal approaches because of uterine position and placental location. Satisfactory amounts of chorionic villi were obtained in all six cases with no maternal discomfort, an occurrence that contrasts with our experience in transvaginal CVS using endovaginal ultrasound guidance. We believe that transvaginal CVS using concurrent transabdominal ultrasound guidance warrants consideration as an alternative technique for first-trimester CVS in selected patients.  相似文献   
134.
Summary Female threespine sticklebacks Gasterosteus aculeatus from a marine population were presented simultaneously with two dummy males that differed in size. When the dummies were moved with a carousel apparatus in a way that roughly simulated a male courtship activity (circling) females responded to the dummies with following behaviour normally directed to courting males. Female sexual response was elicited more effectively by the larger (supernomal) dummy, even though it exceeded by 25% the length of the largest males in the study population. Females did not show complete preference for the larger dummy but allocated courtship effort in proportion to the sizes of the two dummies (Fig. 3). The relative projection areas of the two dummies provided the best predictor of how courtship was allocated between them, suggesting a perceptual basis on which females might select mates. This pattern of partial preference for the supernormal dummy occurred in females that exhibited either high or low amounts of following behaviour and is apparently independent of female responsiveness. Supernormality may therefore provide a mechanism whereby secondary sexual traits can be elaborated, even without evolutionary change in preference for those traits by the opposite sex.  相似文献   
135.
Australia is a sparsely populated country that is well endowed with energy resources, and the size of coal, natural gas, and uranium reserves relative to domestic demand has given Australia the opportunity to become a major exporter of these fuels. This paper assesses Australian supply potential of these three fuels, together with crude oil, through to the early years of the next century. With the exception of crude oil, supply potential appears adequate to meet projected domestic and export demand. However, crude oil supplies are unlikely to meet domestic requirements, and to the shortfall may be considerable.  相似文献   
136.
Long-term residue of DDT compounds in forest soils in Maine   总被引:3,自引:0,他引:3  
Soils in forests sprayed aerially with DDT in 1958-1967 have been sampled for persistence of residues at intervals since then and most recently in 1993. Results of all the samples are presented and show persistence through 30 years, with evidence of decline of residue only in the third decade. The metabolites of DDT--DDE and DDD--increased over time, each comprising about a third of total residue in 1993. Residue continues to be held in the organic mat with little evidence of movement downward to the inorganic soil horizons.  相似文献   
137.
The suggestion that the annual cycle of plant production in tropical oceanic regions may be negligible or non-existent is examined, using data from a year-long cruise series in the eastern tropical Pacific. Results of analysis of variance show a highly significant seasonal effect. Average values of the seasonal cycle were found to range from 127 to 318 mg C/m2/day, a systematic two-fold variation over the year. Annual production was 75 g C/m2/year. Significant differences also were found between longitudes, and a slightly significant interaction occurred between season and longitude. Probable sources of the seasonal cycle include time variation of thermocline topography and variation of nutrient supply from local source areas such as the Costa Rica Dome, Gulf of Tehuantepec, Peru Current extension, and Equatorial Undercurrent domain.  相似文献   
138.
Gabbroic bodies in the Bralorne-Gold Bridge area of southwestern British Columbia are associated with the oceanic Bridge River complex of the western Canadian Cordillera, one of the suspect terranes accreted to North America in the Jurassic. The gabbros are locally cut by tonalites and are structurally interleaved with ultramafic rocks, phyllites, graphitic cherts, and carbonate lenses that comprise the lower part of the Bridge River complex. Their late Carboniferous crystallization age overlaps the depositional age of affiliated supracrustal rocks (Mississippian-Jurassic), some of which have been metamorphosed to blueschist facies. Compositionally, the gabbros resemble mafic plutonic rocks of ophiolitic complexes and gabbroic rocks of the nearby Shulaps Range. They display some affinity to oceanic island arc tholeiitic suites. The Bralorne and Shulaps gabbros include cumulates and appear to have been derived from a single, light REE-depleted, peridotitic source by melting and subsequent fractional crystallization/accumulation of various combinations of plagioclase, pyroxenes, and olivine. The tonalites are compositionally distinct from typical ophiolitic plagiogranites, but might be related to the associated gabbros. The gabbroic bodies occur within tectonic slivers derived from the oceanic crust that floored a deep ocean basin that existed during the late Paleozoic and early Mesozoic. The Bridge River complex comprises fragments of oceanic crust that were tectonically incorporated into an east-verging accretionary prism during a middle/late Triassic to Jurassic collisional event.  相似文献   
139.
This study investigated the relative importance of pheromone trails and visual landmarks on the ability of Lasius niger foragers to relocate a previously used food source. Colonies formed foraging trails to a 1-M sucrose feeder. Sections of this trail were then presented back to the same colony after variable time intervals. Individual outgoing foragers were observed to determine if they walked for 15 cm in the direction of the feeder or not. On newly established pheromone trails formed by 500 ant passages, 77% of the foragers walked in the correct direction vs 31% for control foragers (no trail pheromone). Pheromone trails decayed to the control levels in 20–24 h. Trails formed with fewer ant passages (125 or 30) decayed quicker. The use of visual landmarks was investigated by using trails with outgoing foragers from the colony that established the trail, either in the same room or in a different room, with different visual landmarks, to that used during trail establishment. Approximately 20% more ants walked in the correct direction in the same room vs the different room. This difference decreased to around 10% 2 h after trail establishment, indicating that the ants in the different room were learning the new visual cues to navigate by. Our results show that visual landmarks and pheromone trails are approximately equally useful in initially guiding L. niger foragers to food locations and that these two information sources have a complementary function.  相似文献   
140.
Little is known about the mixed fungal synthesis of high-value aliphatics derived from the metabolism of simple and complex carbon substrates. Trichoderma koningii and Penicillium janthinellum were fed with undecanoic acid (UDA), potatoe dextrose broth (PDB), and their mixture. Pyrolysis Field Ionization Mass Spectrometry (Py-FIMS) together with 1H and 13C Nuclear Magnetic Resonance (NMR) characterized CHCl3 soluble aliphatics in the fungal cell culture. Data from NMR and Py-FIMS analysis were complementary to each other. On average, the mixed fungal species produced mostly fatty acids (28% of total ion intensity, TII) > alkanes (2% of TII) > n-diols (2% of TII) > and alkyl esters (0.8% of TII) when fed with UDA, PDB or UDA+PDB. The cell culture accumulated aliphatics extracellularly, although most of the identified compounds accumulated intracellularly. The mixed fungal culture produced high-value chemicals from the metabolic conversion of simple and complex carbon substrates.  相似文献   
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