Four kinds of CuO catalysts with well-controlled leaf-like （L-CuO）, flower-like （F-CuO）, sea-urchin-like （U-CuO）, and oatmeal-like （O-CuO） morphologies were synthesized by a facile precipitation method assiste...Four kinds of CuO catalysts with well-controlled leaf-like （L-CuO）, flower-like （F-CuO）, sea-urchin-like （U-CuO）, and oatmeal-like （O-CuO） morphologies were synthesized by a facile precipitation method assisted by various chelating ligands. High-resolution transmission electron microscopy and fast Fourier transform infrared spectroscopy indicated that the dominant crystal facets of L-CuO, F-CuO, U-CuO, and O-CuO were {001}, {110}, {001}, and {110}, as well as {001} and {110}, respectively. When tested for the Rochow reaction, it was found that their catalytic performances were dependent on their structures. Among the four CuO catalysts, L-CuO exhibited the best catalytic property, along with the strongest adsorption ability for oxygen and highest reducibility, which are mainly because of its largely exposed {001} facet and large specific surface area. In addition, the amount of the Cu3Si alloy phase, which is the most important reaction intermediate that generated in the reacted region of the Si surface, was measured for the different catalysts. Based on the findings, a detailed reaction mechanism was proposed. This work demonstrates that shape-controlled synthesis of oxide catalysts could be an effective strategy to design and develop efficient catalysts.展开更多
Jasmonates and related compounds, including amino acid conjugates of jasmonic acid, have regulatory functions in the signaling pathway for plant developmental processes and responses to the complex equilibrium of biot...Jasmonates and related compounds, including amino acid conjugates of jasmonic acid, have regulatory functions in the signaling pathway for plant developmental processes and responses to the complex equilibrium of biotic and abiotic stress. But the molecular details of the signaling mechanism are still poorly understood. Statistically significant quantitative structure-property relationship models （r^2 〉 0.990） constructed by genetic function approximation and molecular field analysis were generated for the purpose of deriving structural requirements for lipophilicity of amino acid conjugates of jasmonic acid. The best models derived in the present study provide some valuable academic information in terms of the 2/3D-descriptors influencing the lipophilicity, which may contribute to further understanding the mechanism of exogenous application ofjasmonates in their signaling pathway and designing novel analogs of jasmonic acid as ecological pesticides.展开更多
文摘Four kinds of CuO catalysts with well-controlled leaf-like （L-CuO）, flower-like （F-CuO）, sea-urchin-like （U-CuO）, and oatmeal-like （O-CuO） morphologies were synthesized by a facile precipitation method assisted by various chelating ligands. High-resolution transmission electron microscopy and fast Fourier transform infrared spectroscopy indicated that the dominant crystal facets of L-CuO, F-CuO, U-CuO, and O-CuO were {001}, {110}, {001}, and {110}, as well as {001} and {110}, respectively. When tested for the Rochow reaction, it was found that their catalytic performances were dependent on their structures. Among the four CuO catalysts, L-CuO exhibited the best catalytic property, along with the strongest adsorption ability for oxygen and highest reducibility, which are mainly because of its largely exposed {001} facet and large specific surface area. In addition, the amount of the Cu3Si alloy phase, which is the most important reaction intermediate that generated in the reacted region of the Si surface, was measured for the different catalysts. Based on the findings, a detailed reaction mechanism was proposed. This work demonstrates that shape-controlled synthesis of oxide catalysts could be an effective strategy to design and develop efficient catalysts.
基金the National Natural Science Foundation of China (30500339)the Natural Science Foundation Program of Zhejiang Province(Y407308)
文摘Jasmonates and related compounds, including amino acid conjugates of jasmonic acid, have regulatory functions in the signaling pathway for plant developmental processes and responses to the complex equilibrium of biotic and abiotic stress. But the molecular details of the signaling mechanism are still poorly understood. Statistically significant quantitative structure-property relationship models （r^2 〉 0.990） constructed by genetic function approximation and molecular field analysis were generated for the purpose of deriving structural requirements for lipophilicity of amino acid conjugates of jasmonic acid. The best models derived in the present study provide some valuable academic information in terms of the 2/3D-descriptors influencing the lipophilicity, which may contribute to further understanding the mechanism of exogenous application ofjasmonates in their signaling pathway and designing novel analogs of jasmonic acid as ecological pesticides.
