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991.
992.
The intercalation of aluminosilicate clays proceeds via a critical conformation change. Ion exchange of the poly(oxypropylene)diamine salts allows widening of the clay layers from 12 Å to 20 Å and then a sharp increase to 58 Å. The data indicate a critical conformation change of the intercalated amines, thus providing a new way for manipulating nanomaterials and control of polymer conformations in layered silicate confinement.
993.
Qing Xia Deyuan Li Lanling Zhao Jun Wang Yuxin Long Xue Han Zhaorui Zhou Yao Liu Yiming Zhang Yebing Li Abulgasim Ahmed Abbaker Adam Shulei Chou 《Chemical science》2022,13(10):2841
Developing efficient energy storage and conversion applications is vital to address fossil energy depletion and global warming. Li–O2 batteries are one of the most promising devices because of their ultra-high energy density. To overcome their practical difficulties including low specific capacities, high overpotentials, limited rate capability and poor cycle stability, an intensive search for highly efficient electrocatalysts has been performed. Recently, it has been reported that heterostructured catalysts exhibit significantly enhanced activities toward the oxygen reduction reaction and oxygen evolution reaction, and their excellent performance is not only related to the catalyst materials themselves but also the special hetero-interfaces. Herein, an overview focused on the electrocatalytic functions of heterostructured catalysts for non-aqueous Li–O2 batteries is presented by summarizing recent research progress. Reduction mechanisms of Li–O2 batteries are first introduced, followed by a detailed discussion on the typical performance enhancement mechanisms of the heterostructured catalysts with different phases and heterointerfaces, and the various heterostructured catalysts applied in Li–O2 batteries are also intensively discussed. Finally, the existing problems and development perspectives on the heterostructure applications are presented.The structure–function relationships between heterostructures and their catalytic properties were discussed in detail, and the challenges and improvement strategies for heterostructure based cathodes towards Li–O2 catalysis were also summarized. 相似文献
994.
The Ramanujan Journal - Let F be a number field, and let $$F^{{\text {cyc}}}$$ be obtained by adjoining to F all the roots of unity. We show that as E ranges over all elliptic curves defined over... 相似文献
995.
996.
Chu-En Chou Yi-An Chen Yi-Ching Lin Shih-Chieh Kao Chieh-Yu Chang Yen-Ku Wu 《中国化学会会志》2020,67(12):2198-2203
Described is a formal synthesis of racemic schulzeines B and C that intercepts intermediates developed by Gurjar and co-workers. The synthetic sequence features an annulative coupling of a ketimine and acrylic acid enabling the construction of the benzoquinolizidine nucleus in a highly convergent manner. We also examined a continuous-flow version of the thermal aza-annulation, which proved less practical as compared to the batch processes. 相似文献
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998.
During the course of investigating the anticancer activities of new compounds, we have synthesized a series of novel cyclic N-hydroxyurea derivatives and several carbamate intermediates1–3. Infrared absorption, nuclear magnetic resonance, and electronic absorption spectra were examined in order to confirm the identities and to study the molecular structure of these compounds. 相似文献
999.