1.
Elucidating the mechanism of the structure-dependent enzymatic activity of Fe-N/C oxidase mimics.
Wang, Y, Zhang, Z, Jia, G, Zheng, L, Zhao, J, Cui, X
Chemical communications (Cambridge, England). 2019;(36):5271-5274
Abstract
Herein, we develop an Fe-N/C-CNT nanomaterial with Fe-N3 units as a paradigm for excellent oxidase mimics by theoretical prediction and experimental implementation. The mechanism of the structure-dependent enzymatic activity is systematically investigated and elucidated from the perspective of the different configurations of M-Nx models (x = 0, 3, 4, and 5; M = Fe, Co, and Ni).
2.
Precipitation overrides warming in mediating soil nitrogen pools in an alpine grassland ecosystem on the Tibetan Plateau.
Lin, L, Zhu, B, Chen, C, Zhang, Z, Wang, QB, He, JS
Scientific reports. 2016;:31438
Abstract
Soils in the alpine grassland store a large amount of nitrogen (N) due to slow decomposition. However, the decomposition could be affected by climate change, which has profound impacts on soil N cycling. We investigated the changes of soil total N and five labile N stocks in the topsoil, the subsoil and the entire soil profile in response to three years of experimental warming and altered precipitation in a Tibetan alpine grassland. We found that warming significantly increased soil nitrate N stock and decreased microbial biomass N (MBN) stock. Increased precipitation reduced nitrate N, dissolved organic N and amino acid N stocks, but increased MBN stock in the topsoil. No change in soil total N was detected under warming and altered precipitation regimes. Redundancy analysis further revealed that soil moisture (26.3%) overrode soil temperature (10.4%) in explaining the variations of soil N stocks across the treatments. Our results suggest that precipitation exerted stronger influence than warming on soil N pools in this mesic and high-elevation grassland ecosystem. This indicates that the projected rise in future precipitation may lead to a significant loss of dissolved soil N pools by stimulating the biogeochemical processes in this alpine grassland.