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81.
Dr. Soji Shimizu Yu Haseba Mariko Yamazaki Genji Kumazawa Prof. Nagao Kobayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(16):4822-4828
The first example of the control of porphyrinoid chromophore symmetry based on the positional isomerism of peripheral substituents has been achieved by preparing tetraazaporphyrins (TAPs) with C4h, D2h, C2v, and Cs symmetry due to the relative arrangement of peripheral tert‐butylamino and cyano groups as push and pull substituents, respectively. The four structural isomers were successfully isolated and characterized by 1H NMR spectroscopy and X‐ray crystallography. The band morphology in the Q‐band region varies depending on the molecular symmetry due to the significant perturbation introduced into the chromophore by the push and pull substituents. The C4h and C2v isomers exhibit a single Q band, whereas the Q bands of the D2h and Cs isomers show a marked splitting. The magnetic circular dichroism spectra indicate that the push–pull TAPs retain the properties of the 16‐membered 18π‐electron perimeter generally observed for porphyrinoids. Theoretical calculations have demonstrated that the perturbation introduced by the substituents lowers the D4h symmetry of the parent TAP π‐conjugated system, and this results in significant spectral changes. A novel approach to the fine‐tuning of the spectral properties of porphyrinoids based on changes in the chromophore symmetry is described. 相似文献
82.
Nobuyasu Hanari Taichi Yamazaki Nobuyasu Itoh Takashi Yarita Naomi Fujiki Ryoko Iwasawa Yoshie Aoyagi Masahiko Numata 《Accreditation and quality assurance》2014,19(5):391-396
A certified reference material (CRM) for the determination of perfluorooctanoic acid (PFOA) has been issued as NMIJ CRM 4056-a by the National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (NMIJ/AIST). Purity (kg kg?1) based on a titration method was determined by subtracting the mass fractions of impurities measured using liquid chromatography/mass spectrometry (LC/MS) from those of acids expressed as PFOA measured by a neutralization potentiometric titration. To validate an obtained result, purity based on a mass balance method was determined by subtracting the mass fractions of impurities, measured using LC/MS, Karl-Fischer titration (KFT), and vacuum evaporation, from 1 kg kg?1. Results from both titration and mass balance methods were in agreement within the accepted limits of uncertainty. The certified purity of NMIJ CRM 4056-a was determined to be 0.959 kg kg?1, calculated as the mean of the results obtained with the two methods. The standard uncertainty of the certified purity was evaluated from purity evaluations as well as from sample homogeneity and stability obtained from LC/MS and KFT analyses. Consequently, the expanded uncertainty was estimated to be 0.005 kg kg?1 with a coverage factor of k = 2. 相似文献
83.
84.
K. Suzuki P. Bühler L. Fabbietti N. Herrmann P. Kienle M. Kis Y. Leifels J. Marton E. Widmann T. Yamazaki J. Zmeskal 《Hyperfine Interactions》2009,193(1-3):189-194
We search for the most fundamental kaonic nuclear state, K ??? pp by employing the reaction p?+?p→K ?+??+?X at 3.0 GeV incident beam energy. The experiment makes use of the SIS-18 synchrotron and the ~4π acceptance FOPI apparatus in the cave-B at the GSI, Darmstadt, Germany and aims to collect full kinematics information of the reaction. We look for a signature of the X (?≡?K ??? pp) in both missing mass spectrum by measuring K ?+?, and invariant mass spectrum by measuring decay particles; X?→?Λ?+?p. The experiment is planned to take place in 2009. 相似文献
85.
Sahori Takeda Shin‐ichi Yamazaki 《Rapid communications in mass spectrometry : RCM》2010,24(16):2341-2351
86.
Nakao Hayashi Pavel I. Naumkin Yasuko Yamazaki 《Proceedings of the American Mathematical Society》2002,130(3):779-789
We consider the derivative nonlinear Schrödinger equations
where the coefficient satisfies the time growth condition
is a sufficiently small constant and the nonlinear interaction term consists of cubic nonlinearities of derivative type
where and . We suppose that the initial data satifsfy the exponential decay conditions. Then we prove the sharp decay estimate , for all , where . Furthermore we show that for there exist the usual scattering states, when and the modified scattering states, when
where the coefficient satisfies the time growth condition
is a sufficiently small constant and the nonlinear interaction term consists of cubic nonlinearities of derivative type
where and . We suppose that the initial data satifsfy the exponential decay conditions. Then we prove the sharp decay estimate , for all , where . Furthermore we show that for there exist the usual scattering states, when and the modified scattering states, when
87.
Widmann E Eades J Ishikawa T Sakaguchi J Tasaki T Yamaguchi H Hayano RS Hori M Torii HA Juhász B Horváth D Yamazaki T 《Physical review letters》2002,89(24):243402
Using a newly developed laser-microwave-laser resonance method, we observed a pair of microwave transitions between hyperfine levels of the (n,L)=(37,35) state of antiprotonic helium. This experiment confirms the quadruplet hyperfine structure arising from the interaction of the antiproton orbital angular momentum, the electron spin and the antiproton spin as predicted by Bakalov and Korobov. The measured frequencies of nu(+)(HF)=12.895 96+/-0.000 34 GHz and nu(-)(HF)=12.924 67+/-0.000 29 GHz agree with recent theoretical calculations on a level of 6x10(-5). 相似文献
88.
Hori M Eades J Hayano RS Ishikawa T Sakaguchi J Tasaki T Widmann E Yamaguchi H Torii HA Juhász B Horváth D Yamazaki T 《Physical review letters》2002,89(9):093401
Initial distributions of metastable antiprotonic (4)He and (3)He atoms over principal (n) and angular momentum (l) quantum numbers have been deduced using laser spectroscopy experiments. The regions n = 37-40 and n = 35-38 in the two atoms account for almost all of the observed fractions [(3.0 +/- 0.1)% and (2.4 +/- 0.1)%] of antiprotons captured into metastable states. 相似文献
89.
Vyaselev O Arai K Kobayashi K Yamazaki J Kodama K Takigawa M Hanawa M Hiroi Z 《Physical review letters》2002,89(1):017001
We report Cd nuclear magnetic resonance (NMR) and Re nuclear quadrupole resonance (NQR) studies on Cd(2)Re(2)O(7), the first superconductor among pyrochlore oxides (T(c) approximately 1 K). The Re NQR spectrum at zero magnetic field below 100 K rules out any magnetic or charge order. The spin-lattice relaxation rate below T(c) exhibits a pronounced coherence peak and follows the weak-coupling BCS theory with nearly isotropic energy gap. The results of Cd NMR point to a moderate ferromagnetic enhancement at high temperatures followed by a rapid decrease of the density of states below the structural transition temperature of 200 K. 相似文献
90.
Hisashi Shima Fumiyoshi Takano Hidenobu Muramatsu Masashi Yamazaki Hiroyuki Akinaga Akinori Kogure 《固体物理学:研究快报》2008,2(3):99-101
Kelvin probe force microscopy (KFM) and conductive atomic force microscopy (C‐AFM) together with micro X‐ray photoelectron spectroscopy (XPS) were performed for the stacking structure comprising of the transition metal oxide Co–O and metal electrode, which exhibits large reproducible resistance switching. The application of the external voltage by the C‐AFM cantilever decreases the resistance of Co–O, which well accords with the non‐polar forming process observed in the Pt/Co–O/Pt trilayer, known as the candidate of resistance random access memory (ReRAM). Furthermore, the KFM and micro XPS experimentally revealed that the local reductive reaction of Co–O possibly nucleates the defect related energy levels which dominates the current conduction in the low resistance state. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献