Search

Your search keyword '"Yang, Yunxia"' showing total 24 results
Start Over Author "Yang, Yunxia" Publisher wiley
24 results on '"Yang, Yunxia"'

10. Ultrathin Wall (1 nm) and Superlong Pt Nanotubes with Enhanced Oxygen Reduction Reaction Performance

Author

Xiong Lu, Lu Tao, Yang Yunxia, Junshuang Zhou, Faming Gao, and Yu Dan

Subjects
Materials science, Nanostructure, Nanowire, Active surface area, 02 engineering and technology, General Chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Electrochemistry, 01 natural sciences, 0104 chemical sciences, Catalysis, Biomaterials, Chemical engineering, Oxygen reduction reaction, General Materials Science, 0210 nano-technology, Wall thickness, Biotechnology
Abstract

The synthesis of Pt nanotubes catalysts remains a substantial challenge, especially for those with both sub-nanometer wall thickness and micrometer-scale length characteristics. Combining techniques of insulin fibril template with Pd nanowire template, numerous Pt nanotubes with diameter of 5.5 nm, tube-length of several micrometers, and ultrathin wall thickness of 1 nm are assembled. These tubular catalysts with both open ends deliver electrochemical active surface area (ECSA) of 91.43 m2 gpt-1 which results from multiple Pt atoms exposed on the inner and outer surfaces that doubled Pt atoms can participate in catalytic reactions, further with enhanced electrocatalytic performance for oxygen reduction reaction (ORR). The ultrafine Pt nanotubes represent a class of hollow nanostructure with increased Pt-utilization and large ECSA, which is regarded as a type of cost-effective catalysts for ORR.

Published
2018
Full Text
View/download PDF

24. Responses of a dominant temperate grassland plant (Leymus chinensis) to elevated carbon dioxide and nitrogen addition in China.

Author

Zhang L, Yang Y, Zhan X, Zhang C, Zhou S, and Wu D

Subjects
Biomass, Carbon Dioxide chemistry, China, Nitrogen chemistry, Photosynthesis drug effects, Plant Leaves growth & development, Plant Shoots, Plant Transpiration, Poaceae growth & development, Poaceae metabolism, Time Factors, Carbon Dioxide metabolism, Carbon Dioxide pharmacology, Nitrogen metabolism, Nitrogen pharmacology, Poaceae drug effects
Abstract

The impact of elevated atmospheric CO(2) concentration on plant communities is varied and strongly dependent on the dominant species response, as well as nutrient conditions. Responses of a dominant species (Leymus chinensis) to elevated CO(2) and N application were examined with open-top chambers in a typical temperate grassland in northern China for 3 yr. The significant effect of elevated CO(2) on L. chinensis growth was mainly reflected in the higher photosynthetic rates, increased leaf number, larger shoot and root biomass, and higher root/shoot (R/S) ratio. Enhancement of root biomass induced by elevated CO(2) was larger (40%) than that of shoot biomass (9%). In contrast, N application had a significant impact on most growth indices examined in this study, which was reflected in the enhanced aboveground growth and depressed belowground growth. Nitrogen application significantly reduced the R/S ratio by an average of 40%. Nitrogen addition significantly enhanced the proportion of senescent biomass and decreased the proportion of green leaf biomass under elevated CO(2). There were no CO(2) x N interactions on most of the measured variables, except on photosynthetic rate and the proportion of aboveground biomass. Plant growth variables showed high interannual variation. These results indicate that belowground growth of L. chinensis is more sensitive to elevated CO(2) than is the aboveground. Aboveground growth of L. chinensis is much more sensitive to N application than to CO(2) enrichment. Therefore, the effect of elevated CO(2) on L. chinensis steppe is more likely to be underestimated if only aboveground parts are considered.

Published
2009
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results