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91.
环境思考还没有被大多数商业关注看做是主流业务问题.  相似文献   
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Because of the widespread use of silver nanoparticles in commercial products, discharges of municipal wastewater may be a point source of silver in the aquatic environment. We monitored two sites in western Lake Ontario impacted by discharges from wastewater treatment plants serving the City of Toronto. Concentrations of silver were elevated in bottom sediments and suspended sediments collected at the two sites. We also deployed two types of passive samplers in the water column at the two sites, the newly developed Carbon Nanotube Integrative Samplers for monitoring “CNIS-labile” silver and Diffusive Gradient in Thin Film samplers for monitoring “DGT-labile” silver. Results from these passive samplers indicated that the concentrations of silver at the two sites were either below detection limits or were in the ng/L range. In laboratory experiments where the sediments were re-suspended in Milli-Q water, a small proportion of the silver (i.e., <?25%) was labile and partitioned as colloidal or dissolved silver into the liquid phase after agitation. Nanoparticles tentatively identified as silver nanoparticles were detected by single-particle ICP-MS in suspension after agitation of both suspended and bottom sediments. Therefore, there is a need to assess whether silver species, including silver nanoparticles are transported from wastewater treatment plants into sediments in the aquatic environment. This study is unique in focusing on the in situ distribution of silver in natural waters and in sediments that are potentially impacted by urban sources of nanoparticles.  相似文献   
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The purpose of a barrier coating in food packaging is primarily to increase the shelf life of the foodstuff contained within the packaging, preserve its colour, odour, taste and quality, and thereby reduce food wastage (both at retail outlets and households). While most publications hitherto have compared packaging and barrier-coating materials on the basis of their environmental impacts alone, this paper adopts a more holistic approach by factoring in the economic aspect as well. Four barrier material alternatives—starch, polyethylene, EVOH + kaolin and latex + kaolin are analysed. Two well-defined end-of-life handling scenarios, relevant to Sweden, are: one in which everything except starch is recycled, with starch being composted, and the other in which everything is incinerated. Among the several environmental impact categories which can be analysed, this paper considers only global warming. Two approaches are tested to combine the economic and environmental aspects—normalisation, weighting and aggregating on the one hand, and using the carbon tax to internalise the externality caused by GHG emissions on the other. For the set of weighting factors obtained thanks to a survey conducted by the authors (40.6% for environmental and 59.4% for economic), starch emerges as the most sustainable alternative, followed by polyethylene for both the end-of-life handling scenarios. This tallies with the result obtained by using the carbon tax for internalisation of the externality. The case study, methodology and results presented in this paper, will hopefully be a springboard for more detailed studies of this nature, under the umbrella of sustainability.  相似文献   
96.
Analysis of satellite-telemetry data mostly occurs long after it has been collected, due to the time and effort needed to collate and interpret such material. Delayed reporting reduces the usefulness of such data for nature conservation where timely information about animal movements is required. To counter this problem, we present a novel approach which combines automated analysis of satellite-telemetry data with rapid communication of insights derived from such data. A relatively simple algorithm (based on radial and angular velocity calculated from fixes) allowed instantaneous detection of excursions away from settlement areas and automated calculation of home ranges on the remaining data. Automating the detection of both excursions and home-range calculations enabled us to disseminate ecological insights from satellite-tag data instantaneously through a dedicated web portal. The automated analysis, interpretation, and communication of satellite-tag and other ecological data offer clear benefits to nature conservation research and practice.  相似文献   
97.
A fundamental issue of collective intelligence is whether the collective pattern or process is based on environmental information that explicitly codes for it or arises through self-organization of the individuals. Sometimes, these alternatives occur together. Adaptive systems may also be capable of utilizing different types of mechanism under different conditions. Sendova-Franks et al. (Anim Behav 68:1095–1106, 2004) demonstrated evidence for a self-organization mechanism of brood sorting in the ant Temnothorax albipennis, where the brood are sorted in a series of bands or concentric annuli that increase in size with distance from the colony centre. The work by Cox and Blanchard (J Theor Biol 204:223-238, 2000) suggests an alternative or complementary mechanism whereby the brood pattern is specified by the template of a CO2 gradient. Here, we test for a gaseous template as a necessary condition for brood sorting. Under the experimental condition, we pumped the air out of the nest continuously to prevent the accumulation of any gaseous substances. We compared the brood pattern between the experimental and control conditions according to four characteristics: mean distance from centre, mean nearest-neighbour distance, shape and area. Under the experimental condition, the order of brood types according to the first two characteristics was the same as in the control. The area of the brood pattern was smaller, and its shape elongated under the experimental condition. As expected on the basis of these differences, mean distance from centre was greater and mean nearest-neighbour distance was smaller under the experimental condition (although not statistically significantly) and by the expected amount. We found evidence that ants avoid placing brood in the strongest airflow stream. This could explain the reduced area and elongated shape of the brood pattern under the experimental condition. We conclude that a gaseous template is not a necessary condition for brood sorting. Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.  相似文献   
98.
We studied the ringlet butterfly (Aphantopus hyperantus) in an area of woodland in eastern England. A. hyperantus occurs in open fields, rides (grassy tracks), and glades within the woodland. Mark-recapture methods showed that exchange rates of adult A. hyperantus between fields and glades can be predicted better by distance-via-rides than by direct distance. Behavioral observations showed that A. hyperantus readily moved from glades into rides but rarely moved from glades into dense woodland. The rides are likely to be corridors that act as conduits between fields and glades. In the A. hyperantus system, connectivity could reduce local extinctions and increase rates of recolonization in the event of local extinction.  相似文献   
99.
Complex particles (CP), zein microbound particles and lipid-spray beads (LSB) were prepared and their performances were compared for delivering glycine and a mixture of free amino acids (FAA; alanine, glycine, leucine, serine and tyrosine) to early fish larvae. Measures of performances of microparticles included inclusion, encapsulation, retention and delivery efficiencies in addition to T50 (time to 50% retention) values. CP were prepared containing LSB and a defined dietary mixture that were bound together with zein. CP had significantly higher retention and delivery efficiencies for FAA compared to those of zein microbound particles. Free LSB had higher retention efficiencies for particulate glycine compared with CP, possibly due to differences in suspension characteristics. Free LSB clumped and floated when suspended in water, negatively affecting their acceptability by fish larvae; therefore, LSB should be incorporated into CP for more effective delivery of amino acids. There was a significant inverse correlation between retention efficiencies and solubilities of FAA encapsulated in CP. After 1 h of aqueous suspension, highest retention (44%) and delivery efficiencies (20.3 mg tyrosine g–1 particle) were achieved with tyrosine. T50 values indicated 50% of the initial tyrosine in CP was still available after 36.7 min of suspension in water. Furthermore, CP can deliver FAA to marine fish larvae based on the results of feeding studies in which CP were digested by 3-day-old clownfish larvae; therefore, this particle type could be a valuable tool in studies of larval fish nutrition.Communicated by R.J. Thompson, St. Johns  相似文献   
100.
Schultz C  Grundl T 《Chemosphere》2004,57(10):1301-1306
This work examines the abilities of two smectite minerals (SWa-1 and Wyoming montmorillonite) to adsorb ferrous iron at concentrations from 0.037 mM (2 ppm) to 2.5 mM (240 ppm) over a range of pHs from 4.0 to 8.0. Both sorption isotherm and sorption edge data are presented. Ferrous sorption (Fe(aq)2+ = 0.1 mM) to both SWa-1 and Wyoming montmorillonite over the pH range 4.0-6.75 is relatively constant at approximately 1000 l kg(-1) for both minerals. Sorption in this pH range is attributed to the cation exchange capacity of the clay along the basal surfaces. At pH values above 6.75 the amount of ferrous iron sorbed increases dramatically. At pH 8, sorption (Fe(aq)+ = 0.1 mM) reaches 6600 l kg(-1) and 8000 l kg(-1) for Swa-1 and Wyoming montmorillonite respectively. This is attributed to the specific interaction between ferrous ions and surface sites along mineral edges. The overriding geochemical implication is that in reduced sediments containing more than a few percent clay, the pool of sorbed ferrous iron is vast. This pool of reduced iron is both redox labile and bio-available and is not readily indicated by simple measurement of dissolved Fe2+.  相似文献   
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