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Nancy L. Douglas Kerri M. Mullen Stephanie C. Talmage C. Drew Harvell 《Marine Biology》2007,150(6):1137-1144
Chitinases are involved in defense against chitinaceous pathogens in both invertebrates and vertebrates. This study investigated
whether sea fan corals, Gorgonia ventalina (Linnaeus) collected from the Florida Keys between the summer of 2002 and the summer of 2005 contain chitinases, and whether
these enzymes could serve an analogous protective role against the fungal pathogen, Aspergillus sydowii (Thom et Church). Crude extracts of healthy sea fans contained detectible levels of exochitinase activity in an in vitro
microplate assay using fluorogenic substrates. The exochitinase levels decreased upon injury, agitation, or manipulation of
the tissue. A concurrent, transient increase of exochitinase in the surrounding water suggests that sea fans release chitinases
as a response to these stresses. By contrast, endochitinase was detected in only 2 of 15 sea fans (13%), suggesting a high
degree of variation for this enzyme. Sea fan chitinase-containing seawater and anion exchange chromatography fractions were
both active against A. sydowii in an absorbance-based antifungal assay. The presence of chitinases in sea fan extracts, their release into the surrounding
water upon stress, and their activity against A. sydowii suggests that further study of these enzymes in coral stress responses is warranted. 相似文献
165.
Correlating seabird movements with ocean winds: linking satellite telemetry with ocean scatterometry
Satellite telemetry studies of the movements of seabirds are now common and have revealed impressive flight capabilities and
extensive distributions among individuals and species at sea. Linking seabird movements with environmental conditions over
vast expanses of the world’s open ocean, however, remains difficult. Seabirds of the order Procellariiformes (e.g., petrels,
albatrosses, and shearwaters) depend largely on wind and wave energy for efficient flight. We present a new method for quantifying
the movements of far-ranging seabirds in relation to ocean winds measured by the SeaWinds scatterometer onboard the QuikSCAT
satellite. We apply vector correlation (as defined by Crosby et al. in J Atm Ocean Tech 10:355–367, 1993) to evaluate how the trajectories (ground speed and direction) for five procellariiform seabirds outfitted with satellite
transmitters are related to ocean winds. Individual seabirds (Sooty Shearwater, Pink-footed Shearwater, Hawaiian Petrel, Grey-faced
Petrel, and Black-footed Albatross) all traveled predominantly with oblique, isotropic crossing to quartering tail-winds (i.e.,
105–165° in relation to birds’ trajectory). For all five seabirds, entire track line trajectories were significantly correlated
with co-located winds. Greatest correlations along 8-day path segments were related to wind patterns during birds’ directed,
long-range migration (Sooty Shearwater) as well as movements associated with mega-scale meteorological phenomena, including
Pacific Basin anticyclones (Hawaiian Petrel, Grey-faced Petrel) and eastward-propagating north Pacific cyclones (Black-footed
Albatross). Wind strength and direction are important factors related to the overall movements that delineate the distribution
of petrels at sea. We suggest that vector correlation can be used to quantify movements for any marine vertebrate when tracking
and environmental data (winds or currents) are of sufficient quality and sample size. Vector correlation coefficients can
then be used to assess population—or species-specific variability and used to test specific hypotheses related to how animal
movements are associated with fluid environments. 相似文献
166.
Julie R. Marentette Grace Wang Stephanie Tong Natalie M. Sopinka Matthew D. Taves Marten A. Koops Sigal Balshine 《Behavioral ecology and sociobiology》2011,65(12):2239-2249
Activity levels are modulated by trade-offs between reducing predation risk and the need to move in order to find food or
mates. Because these trade-offs affect males and females differently, many species show sex-specific movement, dispersal patterns,
and spatial navigation capacities, with the sex that gains the most from territory ownership often dispersing less. Unlike
mammals and birds, sex differences in movement among fishes remain poorly studied, and the connections between tests of movement
propensity in the laboratory and in the field are rarely made. Here, we examine the differences in movement between male and
female round goby (Neogobius melanostomus) in both laboratory and field settings. This fish species is invasive in North America and currently undergoing further range
expansions. In the laboratory, round goby males were more active and explored a novel environment more readily than did females.
A large-scale mark–recapture study in Lake Ontario over two years revealed that males moved more than females between years,
but there were no within-year sex differences. Thus, round goby display male-biased movement patterns, providing a comparison
point to dispersal patterns in other taxa. Understanding sex-specific movement of round goby in the field will also help predict
dispersal and population dynamics, both in areas where round goby have already become established and where they are continuing
to invade. 相似文献
167.
Spider monkeys (Ateles spp.) live in social groups that exhibit high levels of fission–fusion dynamics, in which group members form subgroups of varying sizes and compositions. Within these fluid societies, how individuals establish contact with dispersed group members with whom they might choose to associate remains unclear. Long-range vocalizations might facilitate interactions between group members and provide a means of social coordination in fission–fusion societies. We evaluated this possibility for one spider monkey vocalization, the loud call, by examining calling behavior, the relationship between loud calls and changes in subgroup size, and the response of individuals to distant calls and playback experiments in a single study group. We found that 82 % of loud calls were emitted within 30 min of a call from a different location, suggesting that individuals frequently emit loud calls in response to the calls of distant group members. Subgroups that emitted loud calls, especially those that responded to distant calls, were much more likely to experience an increase in subgroup size within an hour after calling than those that did not. Animals also approached distant loud calls more than they avoided or ignored these calls. Finally, playbacks of male calls demonstrated that females respond preferentially to the calls of some individuals over others. Taken together, these results provide support for the hypothesis that spider monkey loud calls function to facilitate and initiate interactions between dispersed group members and suggest that vocal signals can play an important role in influencing social interactions in fission–fusion societies. 相似文献
168.
Reactive walls containing metallic iron have been installed at several commercial sites in the United States to degrade chlorinated organic compounds in groundwater. Although the results of laboratory studies conducted to determine reaction mechanisms have been widely disseminated, little information has been published on the full-scale application of this technology. This article describes the construction, implementation, and cost of in-situ reactive walls at three commercial sites. 相似文献
169.
Fetal cardiac intervention was first proposed in the early 1990s to impact cardiac development and survival of fetuses with fetal aortic stenosis and evolving hypoplastic left heart syndrome (HLHS). Although initial attempts of fetal aortic valvuloplasty were unsuccessful and carried a high rate of morbidity and mortality, our collaborative group at the Brigham and Women's Hospital and Boston Children's Hospital have reinvigorated the procedure using improvements in imaging, anesthesia, balloon catheters, and surgical techniques. Two decades of experience have now allowed us to document the safety of in utero intervention and to achieve a better understanding of the impact of midgestation intervention on developing HLHS. Research into underlying genetics, predictive biomarkers, and ways to incorporate stem cell technology will hopefully allow us to further refine the procedure to most benefit children with this historically lethal disease. 相似文献
170.