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Milligan DB Wilson PF Mautner MN Freeman CG McEwan MJ Clough TJ Sherlock RR 《Journal of environmental quality》2002,31(2):515-524
A new technique is presented for the rapid, high-resolution identification and quantification of multiple trace gases above soils, at concentrations down to 0.01 microL L(-1) (10 ppb). The technique, selected ion flow tube mass spectrometry (SIFT-MS), utilizes chemical ionization reagent ions that react with trace gases but not with the major air components (N2, O2, Ar, CO2). This allows the real-time measurement of multiple trace gases without the need for preconcentration, trapping, or chromatographic separation. The technique is demonstrated by monitoring the emission of ammonia and nitric oxide, and the search for volatile organics, above containerized soil samples treated with synthetic cattle urine. In this model system, NH3 emissions peaked after 24 h at 2000 nmol m(-2) s(-1) and integrated to approximately 7% of the urea N applied, while NO emissions peaked about 25 d after urine addition at approximately 140 nmol m(-2) s(-1) and integrated to approximately 10% of the applied urea N. The monitoring of organics along with NH3 and NO was demonstrated in soils treated with synthetic urine, pyridine, and dimethylamine. No emission of volatile nitrogen organics from the urine treatments was observed at levels >0.01% of the applied nitrogen. The SIFT method allows the simultaneous in situ measurement of multiple gas components with a high spatial resolution of < 10 cm and time resolution <20 s. These capabilities allow, for example, identification of emission hotspots, and measurement of localized and rapid variations above agricultural and contaminated soils, as well as integrated emissions over longer periods. 相似文献
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Eichelter Johanna Wilhelm Harald Mautner Andreas Fahrngruber Barbara Schafler Erhard Eder Andreas Kozich Martin Bismarck Alexander 《Journal of Polymers and the Environment》2021,29(11):3509-3524
Journal of Polymers and the Environment - We evaluated the influence of blending various renewable polymer grades and amounts to allow for high stretchability during stretching at 800 mm/s... 相似文献
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Mark R. Forbes Dean G. McCurdy Keiko Lui Selma I. Mautner J. Sherman Boates 《Behavioral ecology and sociobiology》2006,60(1):87-95
Potential rates of reproduction (PRR) differ between the sexes of many animal species. Adult sex ratios together with PRR
are expected to determine the operational sex ratio (OSR) defined as the ratio of fertilizable females to sexually active
males at any given time. OSR is expected to determine the degree to which one sex competes for another—the limiting sex. We
explored the potential for mate limitation in an intertidal amphipod, Corophium volutator (Pallas). Males have higher PRR than females, but males may be limiting because of extreme female-biased sex ratios observed
in this species. Consistent with this idea, late season females were less likely to be ovigerous and had smaller size-specific
clutches, both of which were associated with seasonal declines in availability of males of reproductive size. Seasonal changes
in ovigery could not be explained by seasonal changes across sites in other factors (e.g., female body size or phenology of
breeding). Smaller females were less likely to become ovigerous later in the season at three of four sites. Seasonal reductions
in clutch size also occurred among small females expected to be reproducing for their first time. In complimentary laboratory
experiments, reduced likelihood of ovigery and reduced fecundity occurred when the number of receptive females was increased
relative to availability of a reproductively active male. Our results suggest male mate limitation can occur seasonally in
this species and that male limitation is regionally widespread and may affect recruitment. 相似文献
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Public policy, private landholders: perspectives on policy mechanisms for sustainable land management 总被引:2,自引:0,他引:2
A variety of tools can be employed in support of environmental policy objectives, but achieving preferred outcomes also requires the cooperation of private landholders and others with vested interests in the land. The Land Stewardship project in the state of Victoria, Australia, is an initiative devoted to exploring the ways in which private landholders could be encouraged towards more sustainable land management. Following the view that the success of policy initiatives is contingent on effective stakeholder engagement, a component of the Land Stewardship project involved a dialogue with landholders about policy tools (e.g., regulation, economic instruments) that might be deployed to encourage improved land management practices. This paper provides an account of the views and attitudes of landholders, as revealed in a series of three workshops, which consisted of discussions about the factors influencing agriculture, participants' interpretations of sustainability, and policy methods. The focus of the paper is on what landholders believe to be the strengths and limitations of standard policy tools, and the essential requirements for these tools to deliver the best land management outcomes. One of the main findings of the project was a 'preference hierarchy' in respect of policy methods, according to which the strongest support was expressed for voluntary and education-based tools, followed by market-based instruments, with command-and-control regulation identified as a measure of 'last resort'. In the paper we reflect also on how the views and outlook of landholders should be positioned relative to other inputs in the design of policy interventions. 相似文献
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