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31.
32.
Ali Izadi-Najafabadi Takeo Yamada Don N. Futaba Hiroaki Hatori Sumio Iijima Kenji Hata 《Electrochemistry communications》2010,12(12):1678-1681
We report the energy and power voltage-dependencies of supercapacitors using single-walled carbon nanotube electrodes. The energy density was dependent on the cell-voltage cubed (up to 4 V: E = 1.43 × V3). The cubic relationship was attributed to the linear increase of the capacitance as a function of voltage, enabled by electrochemical doping. Furthermore, while up to 3.5 V, the maximum power rating of the nanotube electrodes increased as a function of the cell-voltage squared, beyond 3.5 V, a decline in power was observed as a result of depletion of the electrolyte's ions. 相似文献
33.
Matsuda H Nakamura S Fujimoto K Moriuchi R Kimura Y Ikoma N Hata Y Muraoka O Yoshikawa M 《Chemical & pharmaceutical bulletin》2010,58(12):1617-1621
The methanolic extract and its 1-butanol-soluble fraction from the flower buds of Camellia sasanqua THUNB. were found to show inhibitory activities on the release of β-hexosaminidase from rat basophile leukemia (RBL-2H3) cells. From the 1-butanol-soluble fraction, five new acylated oleanane-type triterpene saponins, sasanquasaponins I-V, were isolated together with a known saponin and their chemical structures were elucidated on the basis of chemical and physicochemical evidence. The principal saponin constituents, sasanquasaponins I-III, with an acyl group at the 22-position of the aglycon part showed the inhibitory effects on the release of β-hexosaminidase and some structure-activity relationships were reported. 相似文献
34.
Nonlinear processes in UV optical materials were investigated by using 280-fs, 248-nm pulses. Nonlinear absorption in CaF2 was confirmed to be a two-photon process by using the luminescence of self-trapped excitons, which was also used for the single shot pulse width measurement. The absorption bands due to F centers were identified in CaF2, MgF2, and LiF after several hundred shots at 100 GW/cm2. Absorption at 248 nm was considerable especially in MgF2 and LiF. Self-focusing and self-phase modulation were observed in CaF2. 相似文献
35.
36.
Noriko Hata Shiho Hieda Mika Yamada Rie Yasui Hideki Kuramitz Shigeru Taguchi 《Analytical sciences》2008,24(7):925-928
The formation of a liquid organic ion associate in an aqueous sample was applied to the concentration and determination of cadmium in environmental water samples. Cadmium was converted into a complex with 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol (5-Br-PAPS) in a 40-mL sample solution, and was extracted into a liquid ion associate of phenolsulfonate and benzethonium during phase formation. More than 400-fold enrichment was easily attained by this technique, because the volume of the liquid organic phase formed was very small, ca. 2 microL. After dilution of the organic phase with a small volume of 2-methoxyethanol, the cadmium in the solution was determined by GF-AAS. The detection limit was 0.09 ng/L (3sigma(b)). This method was applied to the determination of cadmium in river water and seawater. 相似文献
37.
Dr. Toru Amaya Dai Hata Dr. Toshiyuki Moriuchi Prof. Dr. Toshikazu Hirao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(46):16427-16433
A reduced form of polyaniline has been shown to induce direct arylation of an arenediazonium salt with an arene (Gomberg–Bachmann reaction) to give the cross‐coupling product in moderate to good yields under mild conditions. Various arenediazonium salts and arenes, including heteroarenes such as furans, thiophenes, and pyrroles, are employed for the reaction. The most favorable combination of substrates is an electron‐poor arenediazonium salt with an electron‐rich heteroarene. Investigation of the mechanism by reactions with radical scavengers and experiments on kinetic isotope effects indicated the occurrence of a radical chain reaction initiated by one‐electron reduction of an arenediazonium salt by the polyaniline. Only 1 mol % (based on aniline tetramer) of the polyaniline is required for the cross‐coupling reaction to occur. This reaction proceeds under metal‐free conditions and with no need for photonic activation. 相似文献
38.
Axisymmetric problem of a nonhomogeneous elastic layer 总被引:3,自引:0,他引:3
Summary The paper deals with a theoretical treatment of elastic behavior for a medium with nonhomogeneous materials property, which
is defined by the relation , i.e., shear modulus of elasticity G varies with the dimensionless axial coordinate by the power product form, arbitrarily. Fundamental differential equation for such nonhomogeneous medium has been already
proposed in [5]. It is given by a second-order partial differential equation. However, it was found that the fundamental equation
is not sufficient in general to solve several kinds of boundary-value problems. On the other hand, it is shown in the present
paper making use of the fundamental equations system for a nonhomogeneous medium, which has been proposed in our previous
paper [7], it is possible to solve axisymmetric problems for a thick plate (layer) subjected to an arbitrarily distributed
load or a concentrated load on its surfaces. Numerical calculations are carried out for several cases, taking into account
the variation of the nonhomogeneous parameter m. The numerical results for displacements stress and components are shown in graphical form.
Accepted for publication 25 March 1997 相似文献
39.
Futaba DN Yamada T Kobashi K Yumura M Hata K 《Journal of the American Chemical Society》2011,133(15):5716-5719
The layer number is of great importance for nanocarbon materials, such as carbon nanotubes (CNTs) and graphene. While simple optical methods exist to evaluate few-layer graphene, equivalent analysis for CNTs is limited to transmission electron microscopy. We present a simple macroscopic method based on the (002) X-ray diffraction peak to evaluate the average wall number of CNTs in the range from single- to few-walled. The key was the finding that the (002) peak could be decomposed into two basic components: the intertube structure (outer-wall contacts) and the intratube structure (concentric shells). Decomposition of the peaks revealed a linear relationship between the average wall number and the ratio of the intertube and intratube contributions to the (002) peak. Good agreement with CNTs having average wall numbers ranging from 1 to ~5 demonstrated this as a macroscopic method for average wall number analysis. 相似文献
40.
Hideki Matsubara Shun-Ichiro Hata Yosuke Kondo Yasuyuki Ishida Hiroshi Takigawa Hajime Ohtani 《Analytical sciences》2006,22(11):1403-1407
The cross-linking structure of the ultra violet (UV)-cured resin prepared from dipentaerithritol hexacrylate (DPHA) was characterized by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) combined with supercritical methanolysis. The MALDI-mass spectrum of the decomposition products obtained by supercritical methanolysis contained a series of peaks of sodium-cationized methyl acrylate (MA) oligomers up to around m/z = 4000 formed through selective cleavage and methylation occurred at ester linkages in UV-cured DPHA. Furthermore, in order to observe widely distributed sequence lengths in the cross-linking junctions, the decomposed products of the cured resin were then fractionated using size exclusion chromatography followed by the MALDI-MS measurements of the individual fractions. The MALDI-mass spectra of the lower molar mass fractions mainly consisted of a series of peaks of MA oligomers around m/z values of several thousands, whereas those of higher molecular weight showed a broad peak up to m/z ca. 180000. The observed distributions of the supercritical methanolysis products suggested that the network junctions in the given UV-cured resin were composed of up to around 2000 acrylate units. 相似文献