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排序方式: 共有4094条查询结果,搜索用时 15 毫秒
941.
942.
Jun Takahashi Kazuto Kawakami Yukiko Kobayashi 《Surface and interface analysis : SIA》2019,51(1):12-16
Although steel research has a very long history, there are still various questions and uncertainties on the fundamental issues of steel materials. Our aim is to clarify the issues by atomic-scale characterization using atom probe tomography (APT). This paper introduced our developed techniques in application of APT into steel materials. The first one is the specimen tip preparation technique from the site-specific regions of interest in steel, which significantly expanded the application field of steel analysis. The second one is the observation technique of trapped hydrogen in steel using our developed “deuterium charge cell,” which accomplished direct observation of the hydrogen trapping site in alloy carbide precipitation strengthened steels. Such atomic-scale analyses bring many new findings in steel materials science. 相似文献
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946.
Tomohiro Ichitsuka Ikko Takahashi Nagatoshi Koumura Kazuhiko Sato Sh Kobayashi 《Angewandte Chemie (International ed. in English)》2020,59(37):15891-15896
Aryl amines are important pharmaceutical intermediates among other numerous applications. Herein, an environmentally benign route and novel approach to aryl amine synthesis using dehydrative amination of phenols with amines and styrene under continuous‐flow conditions was developed. Inexpensive and readily available phenols were efficiently converted into the corresponding aryl amines, with small amounts of easily removable co‐products (i.e., H2O and alkanes), in multistep continuous‐flow reactors in the presence of heterogeneous Pd catalysts. The high product selectivity and functional‐group tolerance of this method allowed aryl amines with diverse functional groups to be selectively obtained in high yields over a continuous operation time of one week. 相似文献
947.
Koji Seto Hiroshi Shimojitosyo Hideyuki Imazaki Hiroshi Matsubara Shigetoshi Takahashi 《Liquid crystals》2013,40(4):517-518
Abstract Chiral 1, 2-diphenylethane derivatives have been synthesized and found to form stable chiral Sc phases exhibiting ferroelectric properties. Comparison with diphenylacetylene derivatives revealed that flexibility of the bridging groups between two benzene nuclei strongly influences the stability of mesophases as well as transition temperatures. 相似文献
948.
Asymmetric epoxidation of trans-cinnam-aldehyde and chalcone by the use of H2sp>O2sp> as an oxidizing agent in alkaline media in the presence of cyclodextrins gave the corresponding epoxides with enantiomeric excess up to 8 %. 相似文献
949.
Masahide Takahashi Masaru Suzuki Yuya Miyagawa Rie Ihara Yomei Tokuda Toshinobu Yoko Takashi Nemoto Seiji Isoda 《Journal of Sol-Gel Science and Technology》2010,54(3):319-324
Photo-curable vinyl modified silicate-phosphate alternating copolymers were prepared by a direct condensation of organochlorosilane
and organophosphoric acid in a solvent-free condition. The obtained copolymers have complete alternating copolymer structure
of silicate and phosphate unit, where the main oxo chain consist of –(Si–O–P–O)
n
-network. They exhibited an excellent solubility of ionic species such as ionic organic dyes. It was also demonstrated the
photo-reduction of Au+ ions to form Au nano particles for plasmonics applications. Micro patterns were also fabricated by soft lithographic processes.
These results indicate that the photo-curable alternating copolymers are one of promising materials for advanced optical information
processing devices. 相似文献
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