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971.
Shunichi Murata Marianna S. Safronova Ulyana I. Safronova Nobuyuki Nakamura 《X射线光谱测定》2020,49(1):200-203
We present visible to near-infrared spectra of highly charged Yb (the atomic number 70) and W (74) obtained with a compact electron beam ion trap. By observing the dependence on the electron beam energy, the charge state that should be assigned to the observed lines is determined. For In-like Yb21+ and W25+ and Sn-like W24+, the experimental spectra are compared with theoretical calculations done by the CI+all-order method. In each spectrum, the most prominent line is identified as the magnetic dipole transition from the first excited fine structure level to the ground level in the ground electronic configuration, 4f3 for In-like ions and 4f4 for Sn-like ions. 相似文献
972.
Dr. Akiko Nakamura Dr. Marwa Abdel Latif Prof. Paul A. Deck Prof. Neal Castagnoli Jr. Prof. James M. Tanko 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(4):823-829
Mechanistic studies with 5-ethyl-3-methyllumiflavinium (Fl+) perchlorate, a biomimetic model for flavoenzyme monoamine oxidase B (MAO-B) catalysis, and the tertiary, allyl amine 1-methyl-4-(1-methyl-1 H-pyrrol-2-yl)-1,2,3,6-tetrahydropyridine (MMTP) reveal that proton-coupled electron transfer (PCET) may be an important pathway for MAO catalysis. The first step involves a single-electron transfer (SET) leading to the free radicals Fl. and MMTP., the latter produced by deprotonation of the initially formed and highly acidic MMTP.+. Molecular oxygen (O2) is found to play a hitherto unrecognized role in the early steps of the oxidation. MMTP and several structurally similar tertiary amines are the only tertiary amines oxidized by MAO, and their structural/electronic properties provide the key to understanding this behavior. A general hypothesis about the role of SET in MAO catalysis, and the recognition that PCET occurs with appropriately substituted substrates is presented. 相似文献
973.
Minoru Yamaji Hideki Okamoto Kenta Goto Shin-ichiro Kato Fumito Tani Yosuke Nakamura 《Tetrahedron letters》2018,59(13):1216-1219
We prepared isomeric compounds 2a and 2b having fused skeletons of coumarin and fluorene by photochemical cyclization of olefin 1. They were successfully separated by chromatography, and characterized by NMR spectroscopic and X-ray crystallographic analyses. The molecular structure of 2a was nonplanar due to the repulsion between the carbonyl group of the coumarin moiety and the methylene group at 9-position on the fluorene skeleton whilst that of 2b was planar. They showed different absorption and fluorescence features in solution whereas their spectral profiles of triplet–triplet absorption and phosphorescence were similar to each other. 相似文献
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978.
Shin-ichi Nakamura 《偏微分方程通讯》2013,38(3-4):743-748
979.
Saori Ichinose Mayumi Nakamura Mayu Maeda Rie Ikeda Mitsuhiro Wada Mio Nakazato Yoshihito Ohba Noboru Takamura Takahiro Maeda Kiyoshi Aoyagi Kenichiro Nakashima 《Biomedical chromatography : BMC》2009,23(9):935-939
A semi‐micro column HPLC‐fluorescence method for routine determination of thiol derivatives such as homocysteine (Hcy), cysteine (Cys) and cysteamine (CA) is described. The thiol derivatives labeled with ammonium‐7‐fluorobenzo‐2‐oxa‐1,3‐diazole‐4‐sulfonate (SBD‐F) were isocratically separated within 12 min on a semi‐micro ODS column (Daisopak‐SP‐120‐5‐ODS‐BP) with a mixture of 25 mm acetate buffer (pH 2.00) and CH3CN as a mobile phase. The purity and similarity of SBD‐thiols by a multi‐wavelength fluorescence detector were more than 92.3 and 96.7%. The detection limits of Hcy, Cys and CA at a signal‐to‐noise ratio of 3 were 0.16, 0.47 and 0.03 µm , respectively. Furthermore validation parameters such as accuracy, precision and robustness of the proposed method showed satisfactory results. Almost 850 plasma sample injections (range 572–1076, n = 3) for a column could be performed without differences in retention time and peak heights of labels. As an application of the proposed method, the determination of thiol derivatives in normal human plasma (n = 103) was demonstrated. The correlation coefficients between Hcy vs Cys and Hcy vs CA were 0.38 and −0.35, respectively. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
980.
S.P. Taneja Y. Nakamura V.K. Garg 《Applied Physics A: Materials Science & Processing》1999,69(1):63-67
-2 , its fast increase similar to the burst effect, and the magnetostriction hysteresis were found in this investigation.
Recieved: 17 December 1997/Accepted: 25 August 1998 相似文献