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91.
Warô Nakanishi Satoko Hayashi Takashi Furuta Norio Itoh Yusaku Nishina Makoto Yamashita 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5-6):1351-1355
Abstract Structures of 1,8-(ArZ)2C14H6O2 and 9-(MeO)-1,8-(ArZ)2C14H7 (Z = S, Se) are determined by X-ray crystallographic analysis. Five C─Z- - -O- - -Z─C atoms of the compounds align linearly, which are analyzed by the extended hypervalent 5c–6e model, based on QC calculations. CT of the 5c–6e occurs as the σ*(C─Z) ← n p (O)→ σ*(Z─C) direction. 相似文献
92.
Yusaku Eda Kennosuke Itoh Yoshio N. Ito Mamoru Fujitsuka Tetsuro Majima 《Supramolecular chemistry》2013,25(9):517-523
2,6-Bis(porphyrin)-substituted 3,5-dimethylpyrazine and its zinc complex bound C70 to yield 1:1 inclusion complexes, which were characterised by ESI-MS, UV–vis, fluorescence and NMR spectroscopies. Association constants of the C70 complexes were determined by fluorescence and NMR spectral analyses. A decrease in absorbance of the Soret band of the pyrazine derivative by the effect of C70 was observed, suggesting the existence of a charge transfer interaction between C70 and porphyrin. Experimentally reliable values for the association constants were obtained by the NMR method and were about six times larger than those of the corresponding C60 complexes. Palladium complexation of the porphyrin–pyrazine ligand was found to enhance the association with fullerene. The association constant of 2,6-bis(porphyrin-Zn)-substituted 3,5-dimethylpyrazine-Pd(II) complex with C70 was determined to be 8400 ± 900 M? 1. From the comparison of the association constants, it was found that inclusion room for C70 in the Pd(II) complex was maintained, juxtaposed between porphyrins attached to the opposite sides of the pyrazine ligands. 相似文献
93.
Yusaku Hioki Hiroki Kuyama Chikako Hamana Kohei Takeyama Koichi Tanaka 《Journal of mass spectrometry : JMS》2013,48(11):1217-1223
We describe here an optimization study of the sample preparation conditions for sensitive detection of peptides by matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐MS). Among many factors in the conditions, we varied the percent acetonitrile in the peptide solution, the percent acetonitrile in the matrix solution and the α‐cyano‐4‐hydroxycinnamic acid (CHCA) concentration in the matrix solution. CHCA was chosen because it is the most frequently used matrix for analyzing peptides. The well‐established dried‐droplet method was employed for sample deposition. The examined range of the concentration of CHCA was from 0.01 to 10 mg/ml, and the MeCN content of the solvent for matrix/analyte was 10% to 50%. The indicator for the detection sensitivity was the S/N ratio of the peaks of peptides used. Highly increased sensitivity (100‐ to 1000‐fold) was observed for the optimal CHCA concentration of 0.1 mg/ml in 20% MeCN/0.1% aq. trifluoroacetic acid (TFA), as compared with the conventional concentration (10 mg/ml) in 50% MeCN/0.1% aq. TFA. For example, the limit of detection of human ACTH 18–39 was 10 amol/well for the optimal condition but 10 fmol/well for the conventional condition. The optimal condition (0.1 mg/ml CHCA in 20% MeCN/0.1% aq. TFA) was verified with five model peptides and provided significant improvement in sensitivity (by two to three orders of magnitude) compared with the conventional conditions. Optimizing the CHCA concentration and solvent composition significantly improved the detection sensitivity in the analysis of peptides by MALDI‐MS. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
94.
Improvement of the rate properties of orthorhombic LiVOPO4 by using a milling approach and acetylene black additives as electronic binder is investigated. The average particle size
of orthorhombic LiVOPO4 was reduced from 12.0 μm to 6.1 μm by milling process by which the Li intercalation capacity into LiVOPO4 increased to 40 mAhg−1 at 0.4 mAcm−2 (C/5). At an optimized acetylene black amount of 15 wt.%, a better uniformity in particle size distribution and dispersion
of the current distribution was obtained. Thus, enhancing the kinetic performance a fairly large reversible intercalation
capacity of Li was achieved with values of 100 and 60 mAhg−1 at high rate conditions of C/5 (0.4 mAcm−2) and 1C (2 mAcm−2), respectively.
Paper presented at the International Conference on Functional Materials and Devices 2005, Kuala Lumpur, Malaysia, June 6 –
8, 2005. 相似文献
95.
Kazuhide Ichikawa Ayumu Wagatsuma Yusaku I. Kurokawa Shigeyoshi Sakaki Akitomo Tachibana 《Theoretical chemistry accounts》2011,130(2-3):237-250
We study the electronic structure of two types of transition metal complexes, the inverted-sandwich-type and open-lantern-type, by the electronic stress tensor. In particular, the bond order $b_\varepsilon$ measured by the energy density which is defined from the electronic stress tensor is studied and compared with the conventional MO-based bond order. We also examine the patterns found in the largest eigenvalue of the stress tensor and corresponding eigenvector field, the ??spindle structure?? and ??pseudo-spindle structure??. As for the inverted-sandwich-type complex, our bond order $b_\varepsilon$ calculation shows that relative strength of the metal-benzene bond among V, Cr, and Mn complexes is V?>?Cr?>?Mn, which is consistent with the MO-based bond order. As for the open-lantern-type complex, we find that our energy density-based bond order can properly describe the relative strength of Cr?CCr and Mo?CMo bonds by the surface integration of the energy density over the ??Lagrange surface?? which can take into account the spatial extent of the orbitals. 相似文献
96.
Caffeoylquinic acid (CQA) is one of the phenylpropanoids which have various bioactivities such as antioxidant, antibacterial, anticancer, antihistamic, and other biological effects. We previously reported that 3,5-di-O-caffeoylquinic acid inhibited amyloid β(1-42)-induced cellular toxicity on human neuroblastoma SH-SY5Y cells and increased the mRNA expression level of glycolytic enzymes and the intracellular ATP level. To investigate structure-activity relationship on the accelerating activity on ATP production, we synthesized 1,4,5-tri-O-caffeoylquinic acid, 4,5-di-O-caffeoylquinic acid, 3,4,5-tri-O-caffeoylquinic acid, and other derivatives. Additionally, we evaluated intracellular ATP level in SH-SY5Y treated with each CQA derivative. As a result, 3,4,5-tri-O-caffeoylquinic acid showed the highest accelerating activity on ATP production among tested compounds. It was suggested that caffeoyl groups bound to quinic acid are important for activity and the more caffeoyl groups are bound to quinic acid, the higher accelerating activity on ATP production exhibits. 相似文献
97.
Bradbury FR Takita M Gurrieri TM Wilkel KJ Eng K Carroll MS Lyon SA 《Physical review letters》2011,107(26):266803
Unprecedented transport efficiency is demonstrated for electrons on the surface of micron-scale superfluid helium-filled channels by co-opting silicon processing technology to construct the equivalent of a charge-coupled device. Strong fringing fields lead to undetectably rare transfer failures after over a billion cycles in two dimensions. This extremely efficient transport is measured in 120 channels simultaneously with packets of up to 20 electrons, and down to singly occupied pixels. These results point the way towards the large scale transport of either computational qubits or electron spin qubits used for communications in a hybrid qubit system. 相似文献
98.
Akiko Fukuda Yusaku Yamamoto Masashi Iwasaki Emiko Ishiwata Yoshimasa Nakamura 《Monatshefte für Mathematik》2013,170(1):11-26
The discrete hungry Toda (dhToda) equation is known as an integrable system which is derived from the study of the numbered box and ball system. In the authors’ paper (Fukuda et al., in Phys Lett A 375, 303–308, 2010), we associate the dhToda equation with a sequence of LR transformations for a totally nonnegative (TN) matrix, and then, in another paper (Fukuda et al. in Annal Math Pura Appl, 2011), based on the dhToda equation, we design an algorithm for computing the eigenvalues of the TN matrix. In this paper, in order to accelerate the convergence speed, we first introduce the shift of origin into the LR transformations associated with the dhToda equation, then derive a recursion formula for generating the shifted LR transformations.We next present a shift strategy for avoiding the breakdown of the shifted LR transformations. We finally clarify the asymptotic convergence and show that the sequence of TN matrices generated by the shifted LR transformations converges to a lower triangular matrix, exposing the eigenvalues of the original TN matrix. The asymptotic convergence is also verified through some numerical examples. 相似文献
99.
Kenichi Takita Keita Shishido Kentaro Kurumada 《Proceedings of the Combustion Institute》2011,33(2):2383-2389
Ignition tests of hydrocarbon fuels in a supersonic airflow by plasma jet (PJ) torches of mixed feedstock, including methane (CH4), such as N2/CH4 and N2/CH4/O2 mixtures, were conducted. The Mach number of the airflow was 2.0, and the total temperature and total pressure of the main flow were those of room conditions. The wall pressure increase due to combustion of hydrocarbon fuels for the N2/CH4 PJ exceeded those of pure O2 and N2 PJs at high electric power input. Equilibrium calculations showed that the main species in high-temperature PJ, aside from N2, were H2, H, and HCN. Considering the slight impact of the HCN species on ignition delay time, the combustion enhancement by the N2/CH4 PJ was caused primarily by the existence of a large amount of H and H2 dissociated from CH4 molecules in the PJ. Moreover, the addition of O2 to the N2/CH4 feedstock further enhanced the combustion and stability of the N2/CH4 PJ. The existence of O2 increased the temperature and the number of H radicals in the PJ exhaust. 相似文献
100.
Nishimura Takahiro Takai Yusaku Shimojo Yu Hazama Hisanao Awazu Kunio 《Optical Review》2021,28(1):42-47
Optical Review - An accurate inversion technique in double integrating sphere (DIS) measurement is essential for determining the optical properties of biological tissue. Although there are several... 相似文献