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91.
Maria-Veronica Sofianou Christos Trapalis Vassils Psycharis Nikos Boukos Tiverios Vaimakis Jiaguo Yu Wenguang Wang 《Environmental science and pollution research international》2012,19(9):3719-3726
Introduction
TiO2 anatase nanoplates and hollow microspheres were fabricated by a solvothermal?Chydrothermal method using titanium isopropoxide as a titanium precursor and hydrofluoric acid as a capping agent in order to enhance the formation of the {001} crystal facets of the anatase nanocrystals.Methods
These different morphological structures of TiO2 anatase can be achieved by only changing the solvent, keeping the amount of the precursor and of the capping agent identical during the solvothermal?Chydrothermal process.Results and discussion
After calcination of the samples, the adsorbed fluoride atoms on the {001} crystal facets of the TiO2 anatase nanocrystals were completely removed from their surface according to XPS analysis. The calcined TiO2 anatase structures were higher crystallized and the specific surface area of the catalysts increased, enhancing their photocatalytic activity in comparison to the non-calcined TiO2 anatase structures. All TiO2 anatase samples with adsorbed as well as non-adsorbed fluoride atoms on their {001} crystal facets, exhibited a higher photonic efficiency than Degussa P25, which was used as a reference.Conclusion
The fluoride free TiO2 anatase nanoplates exhibited the best photocatalytic activity in oxidizing the NO gas to NO2 and NO3 ?. 相似文献92.
State parks play a substantial role in the provision of outdoor recreation opportunities within the United States. Park operators must make crucial decisions in how they allocate capital expenditures, labor, and parkland to maintain recreation opportunities. Their decisions are influenced, in part, by the ecological characteristics of their state’s park system as well as the vitality of their state’s economy. In this research, we incorporate the characteristics of states’ ecosystems and their local economies into a formal production analysis of the states’ park systems from the years 1986 to 2011. Our analysis revealed all three factors of production were positive and inelastic. Expenditures on labor had the largest effect on both park utilization and operational expenditures. Our analysis also found a large degree of variability in the effects of ecological characteristics on both utilization and operating expenditures. Parkland utilization and operational expenditures were more elastic in areas such as Oceania and Mediterranean California relative to other ecological regions. These findings lead us to conclude that state park operators will experience variable levels of difficulty in both accommodating increasing demands for recreation from state parks and maintaining the existing quality of outdoor recreation provided within their system. 相似文献
93.
Schuhfried E Biasioli F Aprea E Cappellin L Soukoulis C Ferrigno A Märk TD Gasperi F 《Chemosphere》2011,83(3):311-317
Sulfides are known for their strong odor impact even at very low concentrations. Here, we report Henry’s law constants (HLCs) measured at the nanomolar concentration range in water for monosulfides (dimethylsulfide, ethylmethylsulfide, diethylsulfide, allylmethylsulfide) and disulfides (dimethyldisulfide, diethylsulfide, dipropylsulfide) using a dynamic stripping technique coupled to Proton Transfer Reaction-Mass Spectrometry (PTR-MS). The experimental data were compared with literature values and to vapor/solubility calculations and their consistency was confirmed employing the extra-thermodynamic enthalpy-entropy compensation effect. Our experimental data are compatible with reported literature values, and they are typically lower than averaged experimental literature values by about 10%. Critical comparison with other freely available models (modeled vapor/solubility; group and bond additivity methods; Linear Solvation Energy Relationship; SPARC) was performed to validate their applicability to monosulfides and disulfides. Evaluation of theoretical models reveals a large deviation from our measured values by up to four times (in units of M atm−1). Two group contribution models were adjusted in view of the new data, and HLCs for a list of sulfur compounds were calculated. Based on our findings we recommend the evaluation and adaption of theoretical models for monosulfides and disulfides to lower values of solubility and higher values of fugacity. 相似文献