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141.
AbstractElectric vehicles (EVs) are currently being discussed as a promising means to increase the energy efficiency and sustainability of today's transport systems. While technological progress and cost reduction are certainly crucial topics for their successful diffusion, consumer acceptance is another issue that warrants further analysis. Based on a large online survey (N?=?969), we compared four consumer groups which differ in their likelihood to purchase an EV with regard to their socio-demographic characteristics, their willingness to pay (WTP) and their perceptions of EVs. The findings indicate that early users in Germany are most likely to be middle-aged men living with their families in a multi-vehicle household who have a higher WTP for an EV. Perceived compatibility of an EV with personal needs seems to be the most influential factor on the stated willingness to purchase an EV. With regard to the promotion of EVs, strengthening their environmental advantages and providing financial incentives for purchase are rated as important measures by a majority of the sample, while performance characteristics which are comparable to conventional vehicles seem to be less important for most participants. Based on the data analyses, we provide recommendations for measures regarding the further development and promotion of EVs. 相似文献
142.
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144.
GPS tracking a marine predator: the effects of precision,resolution and sampling rate on foraging tracks of African Penguins 总被引:1,自引:0,他引:1
We used a prototype GPS logger to track the movements of breeding African Penguins (Spheniscus demersus). The loggers also recorded temperature and water depth, which allowed us to reconstruct foraging tracks in three dimensions, although GPS signals are interrupted when the birds dive. Here we report the loggers performance in the field and assess the effects of GPS error, resolution and sampling rate on estimates of foraging track length and speed. There is a trade-off between sampling rate and battery lifespan. We tested loggers at sampling intervals of 1 s, 10 s, 1 min, 2 min and 10 min. Sampling less frequently increases the chance of tracking an entire foraging trip, but it slows uplink times, slightly decreases the accuracy of positional fixes, and significantly reduces the ability to measure fine-scale aspects of foraging behaviour. Compared with radio or satellite tracking, GPS loggers offer unprecedented detail about animal movements. The results of our analysis suggest that techniques that sample relatively infrequently, such as satellite tracking, underestimate actual track lengths by up to 50%. However, caution is needed when interpreting fine-scale sampling for relatively slow-moving organisms. Re-sampling 1-s tracks suggests that c. 35% of apparent movements at this scale are due to measurement error and, more importantly, the limited spatial resolution of GPS (1.85×1.54 m at the study area). We recommend that researchers use a 1-s sampling rate for fine-scale studies, but resample at less frequent intervals to remove spurious noise for slow-moving animals. At current levels of resolution, animals should move at least 4 m per sampling interval. We provide empirical correction factors to compare inferred track length sampled at different rates, but caution that these are idiosyncratic and strongly dependent on the animals behaviour. Overall, GPS loggers offer a significant advance for studies of fine-scale animal movement patterns.Communicated by O. Kinne, Oldendorf/Luhe 相似文献
145.
Joe Peters 《Journal of Agricultural and Environmental Ethics》1998,11(1):17-47
Preservation of the biological diversity and ecosystems in protected areas can be achieved through projects linking conservation of the protected areas with improved standards of living for resident peoples within surrounding buffer zones. This is the hypothetical claim of the integrated conservation and development project (ICDP) approach to protected area management. This paper, based on several years of experience with the Ranomafana National Park Project in Madagascar, questions the major assumptions of this approach from ethical and practical perspectives. The four basic strategies available to ICDPs – protected areas, buffer zones, compensation, and economic development – are analyzed and shown to be deficient or untested in the case of Ranomafana. Recommendations are made to explore conservation models other than the western conception of the national park, to modify the notion of a buffer zone outside the protected area, to redistribute money or other resources directly to the poor people living in and around the protected areas, and to eliminate the middle men in the development business. An appeal is made to focus on local education, organization and discipline in order to promote self-determination and self-reliance among resident peoples of protected areas. The paper argues that a public works program, similar to the Roosevelt administration's Civilian Conservation Corps of the 1930s, funded through a hard-currency endowment or other innovative financing mechanism, should be tried as a replacement for the currently questionable ICDP approach at Ranomafana. 相似文献
146.
We have developed a basic concept for studying cell biological phenomena using an interdisciplinary approach starting from organic chemistry. Based on structural information available for a given biological phenomenon, unsolved chemical problems are identified. For their solution, new synthetic pathways and methods are developed, which reflect the state of the art in synthesising lipidated peptide conjugates. These compounds are used as molecular probes for the investigation of biological phenomena that involve both the determination of biophysical properties and cell biological studies. The interplay between organic synthesis, biophysics and cell biology in the study of protein lipidation may open up new and alternative opportunities to gain knowledge about the biological phenomenon that could not be obtained by employing biological techniques alone. This fruitful combination is highlighted using the Ras protein as an outstanding example. Included herein is: the development of methods for the synthesis of Ras-derived peptides and fully functional Ras proteins, the determination of the biophysical properties, in particular the ability to bind to model membranes, and finally the use of synthetic Ras peptides and proteins in cell biological experiments. 相似文献
147.
SiobhanPeters 《世界环境》2002,(3):4-6
本文对即将召开的世界可持续发展峰会(WSSD)作了简单介绍,并简要回顾了里约会议以来取得的进展。强调了可持续发展需要全球合作的重要性,并给出了英国政府可持续发展指标体系。 相似文献
148.
Predictive Model of the Effects on Lake Metabolism of Decreased Airborne Litterfall through Riparian Deforestation 总被引:4,自引:0,他引:4
The importance of airborne allochthonous litter to the carbon and nutrient budgets of lakes has been seldom studied. We complied data on the input of terrestrial litter to develop a simple and speculative model to predict the potential consequences of riparian deforestation on one aspect of lake metabolism, specifically the balance between phytoplankton production and plankton respiration. During the autumn of 1992, 56 litter traps were deployed around the littoral zones of four oligotrophic lakes in a densely forested region of northwestern Ontario, Canada. The airborne litter input was estimated to be 32 g dry weight per meter of forested shoreline per year. Allochthonous litter input per unit offshore distance was related to the size of riparian trees, their proximity to the shoreline, and the elevation of their canopy. Combining our data with those from other studies suggests that terrestrial litter can contribute up to 15% of the total carbon supply to oligotrophic lakes and up to 10% of the total phosphorus supply to lakes with a large surface area relative to that of their drainage basin. These results were incorporated into a simple model that predicts that removal of shoreline trees could increase the ratio of plankton production to respiration in oligotrophic lakes situated within small drainage basins. Such lakes may therefore shift from allotrophy to increasing autotropy (energy self-sustenance) following riparian deforestation. 相似文献
149.
Radular function in the muricid gastropod Urosalpinx cinerea follyensis Baker during shell penetration was examined with slow-motion picture photography and scanning electron microscopy. Particular attention was paid to possible injury of buccal structures by radular cusps. The presence of a flexible cuticulated buccal armature, and delicate synchronization of movements of odontophoral cartilages, subradular membrane, teeth, and buccal mass, explain the absence of shredding of live buccal tissues. Some light abrasion was evident, but generally only in the cuticulated gully of the subodontophoral shield, on the rim of the jaw, and on the anterior edge of the esophageal valve. Rasping at the surface of incomplete bore-holes is done by major cusps of rachidian teeth over the bending plane. Marginal teeth lie on the slopes of the odontophore, generally remain depressed below the level of rachidian teeth, and thus scrape the shell only lightly, if at all. The sharp posteriorly recurved shape of central and lateral rachidian cusps enhances their scooping effectiveness. These teeth produce smooth, conspicuous traces in the soft shell of Mya arenaria and shallow traces in the harder shell of Mytilus edulis Linné. The impact of individual cusp strikes was not evident in traces. With wear, rachidian cusps become increasingly blunted, a reflection of their ploughing action over chemically weakened shell, and are eventually sanded flat. Marginal teeth wear primarily at their ends, the tips becoming truncated as they pass lightly over the shell surface. The advancing edge of the odontophore during rasping strokes, plotted on the image from motion pictures moves slowly at first, then more rapidly in the middle of the stroke, and slows again at the end. Duration of strokes ranged from 0.45 to 0.75 sec. Duration of rasping cycles varied from 1.3 to 2.0 sec. The number of transverse rows of teeth passing over the bending plane during the rasping stroke varied from 14 to 32, and the average time for the passage of one transverse row over the bending plane ranged from 20 to 48 msec. The number of transverse rows of teeth remaining exposed beneath the odontophore below the bending plane at the end of the rasping stroke, and between the bending plane and the anterior end of the sulcus in the radular diverticulum, was approximately 10. 相似文献
150.
Lower and upper survival temperatures of microthalli of 25 species of South American Phaeophyceae isolated from central Peru (14°S) to the Canal Beagle (55°S) were determined using 2-wk exposure for the upper and 4-wk exposure for the lower limit. All species survive 4 wks at -2°C. With respect to the upper limit, species reported only from southernmost South America tolerate 19.9 to 24.5°C (n=8), and species occurring from Cape Horn to central Chile 24.6 to 27.4°C (n=7). Three species that occurred as far north as northern Chile and Peru before the 1982–1983 El Niño event, and whose northern limit was dramatically shifted southwards in 1983, tolerate 20.8 to 25.3°C, whereas five species that have survived in Peru tolerate 25.6 to 28.5°C. Tinocladia falklandica which tolerates 27.8 to 28.1°C but lives only in southernmost South America and Striaria attenuata, which tolerates 31.6 to 31.9°C but occurs at ca. 42°S, are exceptional. Their high temperature tolerance may have no adaptive value in South America. They are restricted to the cold-temperate region due to low temperature requirements for reproduction or for reasons yet unknown. In general, the northern distributional limits of the Phaeophyceae studied along the temperate Pacific coast of South America are reproduction boundaries, except in El Niño years when they are redefined according to the species' upper suvival limits. Temperature tolerance of isolates from northern Chile and Peru agrees well with maximum temperatures reached during the 1983 El Niño. 相似文献