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371.
Dominant species identity, not community evenness, regulates invasion in experimental grassland plant communities 总被引:6,自引:0,他引:6
While there has been extensive interest in understanding the relationship between diversity and invasibility of communities, most studies have only focused on one component of diversity: species richness. Although the number of species can affect community invasibility, other aspects of diversity, including species identity and community evenness, may be equally important. While several field studies have examined how invasibility varies with diversity by manipulating species identity or evenness, the results are often confounded by resource heterogeneity, site history, or disturbance. We designed a mesocosm experiment to examine explicitly the role of dominant species identity and evenness on the invasibility of grassland plant communities. We found that the identity of the dominant plant species, but not community evenness, significantly impacted invasibility. Using path analysis, we found that community composition (dominant species identity) reduced invasion by reducing early-season light availability and increasing late-season plant community biomass. Nitrogen availability was an important factor for the survival of invaders in the second year of the experiment. We also found significant direct effects of certain dominant species on invasion, although the mechanisms driving these effects remain unclear. The magnitude of dominant species effects on invasibility we observed are comparable to species richness effects observed in other studies, showing that species composition and dominant species can have strong effects on the invasibility of a community. 相似文献
372.
Velten Sarah Jager Nicolas W. Newig Jens 《Environment, Development and Sustainability》2021,23(10):14619-14641
Environment, Development and Sustainability - More and better collaboration between farmers and other stakeholders has repeatedly been identified as a key strategy for sustainable agriculture.... 相似文献
373.
Sarah Hitchner John Schelhas J. Peter Brosius Nathan P. Nibbelink 《Environmental Communication: A Journal of Nature and Culture》2019,13(3):353-365
For cultures around the world, a journey, particularly one undertaken by foot through landscapes that are simultaneously natural and cultural, is both a metaphor for the discovery of the self and the divine and an embodied practice in the physical realm. Here we analyze twenty-six publicly available blogs of thru-hikers of the John Muir Trail in the Sierra Nevada mountains of California, U.S.A. Cognizant of the critiques of the intrusion of technology into wilderness areas, we examine how the communication medium of travel blogs becomes a vehicle for both self-reflection and for sharing spiritual experiences, and how the act of blogging merges virtual and corporeal communities formed among hikers. It is in the intersection of these social networks and mobile communication technologies that we find suggestions of changing relationships between a subculture of tech-savvy and highly connected hikers sometimes called “flashpackers” and the physical landscapes through which they travel. 相似文献
374.
375.
Andrew Kliskey Lilian Alessa Sarah Wandersee Paula Williams Jamie Trammell Jim Powell Jess Grunblatt Mark Wipfli 《Sustainability Science》2017,12(2):293-303
Integrative research is increasingly a priority within the scientific community and is a central goal for the evolving field of sustainability science. While it is conceptually attractive, its successful implementation has been challenging and recent work suggests that the move towards interdisciplinarity and transdisciplinarity in sustainability science is being only partially realized. To address this from the perspective of social-ecological systems (SES) research, we examine the process of conducting a science of integration within the Southcentral Alaska Test Case (SCTC) of Alaska-EPSCoR as a test-bed for this approach. The SCTC is part of a large, 5 year, interdisciplinary study investigating changing environments and adaptations to those changes in Alaska. In this paper, we review progress toward a science of integration and present our efforts to confront the practical issues of applying proposed integration frameworks. We: (1) define our integration framework; (2) describe the collaborative processes, including the co-development of science through stakeholder engagement and partnerships; and (3) illustrate potential products of integrative, social-ecological systems research. The approaches we use can also be applied outside of this particular framework. We highlight challenges and propose improvements for integration in sustainability science by addressing the need for common frameworks and improved contextual understanding. These insights may be useful for capacity-building for interdisciplinary projects that address complex real-world social and environmental problems. 相似文献
376.
The primary goal of this study is to compare wet versus dry sampling methods for three different media, (Whatman 41 filter papers, GhostWipes, and SKC Smear Tabs), These media were selected because they are the most commonly used means for the collection of beryllium from contaminated surfaces within the DOE Complex. A range of known concentrations of beryllium was introduced onto a smooth nonporous surface. All three types of media were tested for collection efficiency in both the wet and dry mode and analyzed by inductively-coupled plasma atomic emission spectrometry (ICP-AES). 相似文献
377.
Loss of fish habitat in North America has occurred at an unprecedented rate through the last century. In response, the Canadian
Parliament enacted the habitat provisions of the Fisheries Act. Under these provisions, a “harmful alteration, disruption, or destruction to fish habitat” (HADD) cannot occur unless authorised
by Fisheries and Oceans Canada (DFO), with legally binding compensatory habitat to offset the HADD. The guiding principle
to DFO’s conservation goal is “no net loss of the productive capacity of fish habitats” (NNL). However, performance in achieving
NNL has never been evaluated on a national scale. We investigated 52 habitat compensation projects across Canada to determine
compliance with physical, biological, and chemical requirements of Section 35(2) Fisheries Act authorisations. Biological requirements had the lowest compliance (58%) and chemical requirements the highest (100%). Compliance
with biological requirements differed among habitat categories and was poorest (19% compliance) in riparian habitats. Approximately
86% of authorisations had larger HADD and/or smaller compensation areas than authorised. The largest noncompliance in terms
of habitat area occurred in riverine habitat in which HADDs were, on average, 343% larger than initially authorised. In total,
67% of compensation projects resulted in net losses of habitat area, 2% resulted in no net loss, and 31% achieved a net gain
in habitat area. Interestingly, probable violations of the Fisheries Act were prevalent at half of the projects. Analyses indicated that the frequency of probable Fisheries Act violations differed among provinces. Habitat compensation to achieve NNL, as currently implemented in Canada, is at best
only slowing the rate of habitat loss. In all likelihood, increasing the amount of authorised compensatory habitat in the
absence of institutional changes will not reverse this trend. Improvements in monitoring and enforcement are necessary to
move towards achieving Canada’s conservation goals. 相似文献
378.
This article explores individual and community action taken in response to perceived environmental risks by investigating
the determinants of environmental action across a range of action types. A conceptual framework is first presented, which
provides a foundation for investigating the role of local compositional (i.e., individual characteristics), contextual (i.e.,
neighborhood environment), and collective (i.e., social networks) factors in environmental action. To test the utility of
the conceptual framework, a quantitative survey was administered to a random sample of households (n = 512) in Hamilton, Canada.
The results suggest that the predictors of environmental action vary by action type (i.e., personal change, individual civic
action, and cooperative civic action), and that factors related to perceived environmental exposure and social capital generally
play a stronger, more consistent role in civic environmental action than sociodemographic or neighborhood factors. The results
underscore the role of social connection in responses to perceived environmental risks. 相似文献
379.
The monitoring of resource condition is receiving renewed attention across several levels of government in Australia. This
interest is linked to substantial investment in environmental remediation and aquatic ecosystem restoration in particular.
In this context, it is timely to consider principles which ought to guide the development and implementation of monitoring
programmes for wetland ecosystems. A framework is established which places monitoring in the context of the strategic adaptive
management of wetlands. This framework requires there has to be clear goals for the extent and condition of the resource,
with these goals being defined within thresholds of acceptable variability. Qualitative and, where possible, quantitative
conceptual models linking management interventions to management goals should be the basis of indicator selection and assessment.
The intensity of sampling ought to be informed by pilot surveys of statistical power in relation to the thresholds of acceptable
variability identified within the management plan. 相似文献
380.
Binstock D Gutknecht W Sorrell K Haas C Winstead W McCombs M Brown G Salmons C Harper SL 《Journal of environmental monitoring : JEM》2012,14(5):1417-1427
Lead in paint continues to be a threat to children's health in cities across the United States, which means there is an ongoing need for testing and analysis of paint. This ongoing analytical effort and especially development of new methods continue to drive the need for diagnostic testing materials that provide the analytical challenges of real-world paints. To this end, 31 different types of paint test materials were developed and prepared. Preparation of the materials included development of lead-containing paint films yielding an overall relative standard error for one individual test sample being less than 10%. The 31 diagnostic test materials prepared with these paint films included two lead pigments; lead concentrations from nominally 0 to 2.0 mg lead/cm(2) (0 to 5% lead by weight); overlayers of both "lead-free," oil-based and water-based paints; Al, Ba, and Mg as potential chemical interferents; red and black potential color interferents; and substrates of wood, metal, masonry, and plaster. These materials challenge each step in method development and evaluation, including paint sample collection and preparation, lead extraction, and measurement of solubilized lead. When the materials were used to test performance of a new lead-in-paint testing method based on extraction using a rotor/stator method and measurement using turbidimetry, the results agreed to within ±20% of the expected lead values for 30 out of 31 of the diagnostic test materials, thereby demonstrating their levels of quality and utility. 相似文献