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Three populations of the grazing isopod Idotea balthica were exposed to high CO2 treatment for a period of 20 days to investigate the effect of ocean acidification (OA) on animal health and immunocompetence. The results of the populations from more saline habitats were comparable and showed a 60–80 % decrease in immune response as a result of the high CO2 treatment. Analysis of protein carbonyls showed no treatment effect, indicating that short-term OA does not increase oxidative protein damage. Meanwhile, the third tested population from the lower saline Baltic Sea had higher background protein carbonyl levels. Ocean acidification in addition to this resulted in 100 % mortality. The results of this study show that OA reduced immunocompetence of this marine isopod. In addition, populations and individuals in poor health are potentially at greater risk to succumb under OA. 相似文献
25.
Leadership theories have shifted over the last few decades from a focus on managerial functions and economic leader–follower exchanges toward greater focus on the interpersonal dynamics occurring within the leadership process. Theories such as transformational, ethical, authentic, and other “newer genre” theories were created to address neglected topics such as leader vision and inspirational messages, transparency, emotional effects, morality, individualized attention, and intellectual stimulation. Critiques of these theories, however, have been raised. In this paper, we address five of those critiques and argue for the validity and practical effectiveness of the new genre theories. Further, we describe how newer genre leadership research should be viewed as a performative epistemology, entailing a process of co‐creation involving scholars and practitioners. Finally, from this view, we provide general ideas for leader development. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
26.
Sarah Joy Bittick Nicholas D. Bilotti Heather A. Peterson Hannah L. Stewart 《Marine Biology》2010,157(2):317-323
Habitat associations are an integral part of coral reef community structure. Commonly, one organism lives in such close association
within or near another that a spatial refuge occurs, whereby one of the organisms provides protection to the other. This is
often the result of defenses of the host deterring an associate organism’s consumers. In Moorea, French Polynesia, the range
and abundance of the brown macroalga, Turbinaria ornata, have increased drastically since 1980 such that dense aggregations of this macroalga are a dominant component of the backreef
habitat. Turbinaria ornata is both mechanically and chemically defended from herbivores. Other species of macroalgae grow within aggregations of Turbinaria and may benefit from these defenses. This study investigates whether aggregations of Turbinaria create a refuge from herbivory for associate macroalgae. When Turbinaria aggregations were removed experimentally, there was a significant increase in the number of associate algal species. Moreover,
an herbivory assay using the palatable local alga Acanthophora spicifera identified herbivory as the mechanism for lower diversity on bommies lacking Turbinaria aggregations. The local increase in algal richness due to the refuge from herbivory afforded by Turbinaria may be an important contribution to macroalgal and community dynamics on reefs in Moorea, French Polynesia. 相似文献
27.
Deployment in a crisis zone is a perilous undertaking. Little is known right now about how humanitarian workers relate social and professional goals to lived experiences of high-risk environments. In South Sudan, ranked as the most dangerous country globally for aid workers, 20 international humanitarian staff were interviewed to examine their sense of place, well-being, and vocation, using thematic and interpretative phenomenological analysis. Subjectivities of humanitarian space hinged upon negotiating physical hardships and social relationships: Juba, the capital, was described as a ‘prison’ and a ‘party hotspot’. For expatriate staff, making sense of spatial, social, and professional transience was sharply gendered and rooted in the subjectivities of risk-taking, crisis management, and career-building. Two policy measures are highlighted here to address the implications of transience for human well-being and organisational effectiveness. Efforts to support teams and structure work environments, altering the humanitarian and vocational bubble, will help to develop resilience at the heart of humanitarian systems. 相似文献
28.
Hannah W. McKenzie Christopher L. Jerde Darcy R. Visscher Evelyn H. Merrill Mark A. Lewis 《Environmental and Ecological Statistics》2009,16(4):531-546
Global Positioning System (GPS) collars are increasingly used to study animal movement and habitat use. Measurement error
is defined as the difference between the observed and true value being measured. In GPS data measurement error is referred
to as location error and leads to misclassification of observed locations into habitat types. This is particularily true when
studying habitats of small spatial extent with large amounts of edge, such as linear features (e.g. roads and seismic lines).
However, no consistent framework exists to address the effect of measurement error on habitat classification of observed locations
and resulting biological inference. We developed a mechanistic, empirically-based method for buffering linear features that
minimizes the underestimation of animal use introduced by GPS measurement error. To do this we quantified the distribution
of measurement error and derived an explicit formula for buffer radius which incorporated the error distribution, the width
of the linear feature, and a predefined amount of acceptable type I error in location classification. In our empirical study
we found the GPS measurement error of the Lotek GPS_3300 collar followed a bivariate Laplace distribution with parameter ρ = 0.1123. When we applied our method to a simulated landscape, type I error was reduced by 57%. This study highlights the
need to address the effect of GPS measurement error in animal location classification, particularily for habitats of small
spatial extent. 相似文献
29.
Fungiacyathus marenzelleri (Vaughan, 1906) is a deep-water solitary coral, cosmopolitan in distribution that is found at depths of 300–6,328 m. This
study examined gametogenesis, inter-annual variability and reproductive periodicity of F. marenzelleri collected from Station M (34°50′N, 123°00′W) in the northeast Pacific at a depth of 4,100 m. Samples were collected (May,
June, October 1996; August 1998; February, June 2001; and June 2002) and histologically processed with spermatogenic stage,
oocyte size and fecundity measured. Four stages of spermatogenesis were identified and all males contained multiple stages
of sperm development in each seasonal sample. Three stages of oocyte development were identified; previtellogenic (<28–150 μm),
vitellogenic (150–300 μm) and late vitellogenic (300–400 μm). Comparison of mean oocyte diameters among sampling dates showed
there were no inter-annual variations or seasonal differences. Overall, fecundity was 1,290 (±407) oocytes polyp−1, and with no significant differences between sample months. Fecundity was not polyp-size dependent. This study shows a similar
quasi-continuous mode of reproduction to this species examined from the Northeast Atlantic Ocean, but the fecundity is reduced
by 50%. The reproductive output may fluctuate in relation to the input of organic material at this site, as shown by non-significant
trends in the oocyte size-frequency and fecundity data. A quasi-continuous output of gametes would promote successful fertilisation
and wide dispersal of the lecithotrophic larvae. 相似文献
30.
Benavides-Lopez Jose Luis ter Hofstede Hannah Robillard Tony 《Die Naturwissenschaften》2020,107(1):1-11
The Science of Nature - The capability of producing sounds and vibrations is well known in insects and is thought to be a form of intra- and interspecific communication. Sounds and vibrations are... 相似文献