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91.
92.
K Yoshino M Fujiwara A Tanaka S Takahashi Y Nambu A Tomita S Miki T Yamashita Z Wang M Sasaki A Tajima 《Optics letters》2012,37(2):223-225
A high-speed quantum key distribution system was developed with the wavelength-division multiplexing (WDM) technique and dedicated key distillation hardware engines. Two interferometers for encoding and decoding are shared over eight wavelengths to reduce the system's size, cost, and control complexity. The key distillation engines can process a huge amount of data from the WDM channels by using a 1 Mbit block in real time. We demonstrated a three-channel WDM system that simultaneously uses avalanche photodiodes and superconducting single-photon detectors. We achieved 12 h continuous key generation with a secure key rate of 208 kilobits per second through a 45 km field fiber with 14.5 dB loss. 相似文献
93.
Effects of L-Aspartic acid (L-Asp) on step retreat kinetics in the dissolution of calcite were investigated. The step retreat velocities under surface-controlled kinetics were determined from in-situ atomic force microscopic observations using an improved flow-through system. Comparison of the present results with those obtained under a mixed kinetics condition revealed that the addition of L-Asp promotes the transport process in the calcite dissolution through acid–base and/or complex forming reactions in the diffusion boundary layer. Additionally, promotion of the acute and obtuse step retreats by the L-Asp additive was observed under surface-controlled kinetics. This report is the first to clarify that L-Asp promotes surface processes in the dissolution of calcite. 相似文献
94.
T. Ogasawara A. Yoshino H. Okabayashi C. J. O''Connor 《Colloids and surfaces. A, Physicochemical and engineering aspects》2001,180(3):317-322
In the 3-aminopropyltriethoxy silane–deuterated ethanol–H2O system, the rate of release of ethanol from the ethoxy groups, a reaction which occurs during the condensation process, has been followed by use of 1H NMR spectroscopy at different temperatures. Two separate reaction processes have been identified, and values of the reaction rate constants and thermodynamic parameters (Ea, ΔH‡ and ΔS‡) have been calculated. 相似文献
95.
A. Yoshino M. Ishida H. Yuki H. Okabayashi H. Masuda C. J. O'Connor 《Colloid and polymer science》2001,279(11):1144-1148
A series of N-acetyl-L-glutamic acid oligopeptide benzyl esters with exact residue numbers 4, 6, and 12 has been synthesized by a stepwise procedure.
For these oligopeptide–dioxane binary systems, the behavior of the liquid-crystalline phases has been examined␣by the use
of 2H NMR, and the results indicate that highly ordered aggregates formed by these oligopeptides in dioxane are in an alignment
similar to that in a nematic mesophase.
Received: 27 February 2001 Accepted: 8 May 2001 相似文献
96.
Momoko Ishida Rika Ohara Fuka Miyagawa Hiroe Kikuzaki Kosuke Nishi Hiroyuki Onda Nanami Yoshino Takuya Sugahara 《Molecules (Basel, Switzerland)》2022,27(13)
Cuminum cyminum L. (cumin) is an annual plant of the Umbelliferae family native to Egypt. We previously showed that the aqueous extract of cumin seeds suppresses degranulation by downregulating the activation of antigen-induced intracellular signaling molecules in rat basophilic leukemia RBL-2H3 cells. However, the active substances in the extract have not yet been identified. Accordingly, herein, we aimed to ascertain the water-soluble substances present in cumin seeds that inhibit degranulation, which led to the identification of umbelliferose, a characteristic trisaccharide present in plants of the Umbelliferae family. Our study is the first to reveal the degranulation-suppressing activity of umbelliferose, and quantification studies suggest that cumin seed powder contains 1.6% umbelliferose. Raffinose, an isomer of umbelliferose, was also found to significantly suppress antigen-induced degranulation, but less so than umbelliferose. Both umbelliferose and raffinose contain sucrose subunits in their structures, with galactose moieties bound at different sites. These differences in structure suggest that the binding of galactose to the sucrose subunit at the α1-2 bond contributes to its strong degranulation-inhibiting properties. 相似文献
97.
Dr. Tatsuhiko Yoshino Shun Satake Prof. Dr. Shigeki Matsunaga 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(33):7346-7357
Transition-metal-catalyzed C−H functionalization reactions with Cp*MIII catalysts (M=Co, Rh, Ir) have found a wide variety of applications in organic synthesis. Albeit the intrinsic difficulties in achieving catalytic stereocontrol using these catalysts due to their lack of additional coordination sites for external chiral ligands and the conformational flexibility of the Cp ligand, catalytic enantioselective C−H functionalization reactions using the Group 9 metal triad with Cp-type ligands have been intensively studied since 2012. In this minireview, the progress in these reactions according to the type of the chiral catalyst used are summarized and discussed. The development of chiral Cpx ligands the metal complexes thereof, artificial metalloenzymes, chiral carboxylate-assisted enantioselective C−H activations, enantioselective alkylations assisted by chiral carboxylic acids or chiral sulfonates, and chiral transient directing groups are discussed. 相似文献
98.
Tatsuhiko Saito 《Semigroup Forum》1988,37(1):37-43
Communicated by J. M. Howie 相似文献
99.
An analytical approach is presented to determine the performance of a tunable wavelength converter based on four wave mixing (FWM) in a single mode fiber (SMF) with two pump lasers. The analysis is carried out for an intensity modulated (IM) signal taking into considerations the effects of spectral broadening due to FWM and laser phase noise. The results evaluated at a bit rate of 10 Gb/s show that the signal power is substantially higher at lower values of wavelength separation. For example, for input powers of 10 mW each, wavelength separation of 4 nm between the pump-2 and the input signal, the output converted power is found to be –10 dBm corresponding to wavelength separation of 2 nm between pump-1 and converter signal. The corresponding crosstalk power is found to be –25 dBm at a channel separation of 3 times bit rate. 相似文献
100.
Mössbauer spectra and electrical conductivities were measured for the purpose of studying on the conduction mechanism of xFe2O3?(40-x)V2O5?60P2O5 glasses. The ratios Fe2+/Fe2++Fe3+ in xFe2O3?(40-x)V2O5?60P2O5 glasses were determined by Mössbauer spectroscopy. On the composition dependence of D. C. conductivities in these glasses, the minimum of log σ at each temperature was obtained at 25Fe2O3?15V2O5?60P2O5. The conductivities of ternary glassses in Fe rich region could be explained only by the changes of carrler (Fe2+) concentration and the hopping conduction between Fe2+ ions and Fe3+ ions in binary glasses. In V rich region, the saturation tendency of D. C. conductivities are observed. It was suggested to be explained by increasing of V4+ ions due to the influence of Fe ions. 相似文献