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911.
Aminoalkyl celluloses (AmACs) were prepared from 6-chlorodeoxycellulose and aliphatic diamines H2N(CH2)mNH2 (m = 2, 4, 6, 8). Their adsorption and desorption of divalent heavy metal ions such as Cu2+, Mn2+, Co2+, Ni2+ and their mixtures were also investigated in detail. Adsorption of metal ions on AmACs was remarkably affected by the pH of the solution, the metal ion and its initial concentration, and also the number of methylene units in the diamines. No adsorption of metal ions occurred on AmACs in strongly acidic solutions. However, metal ions were adsorbed rapidly on AmACs from weakly acidic solutions and the amount of adsorption increased with increasing pH. The effectiveness of AmACs as adsorbents decreased with increasing length of the methylene moiety, and AmACs from ethylenediamine (m = 2) was most effective. The adsorption of metal ions on AmACs was in the order Cu2+ > Ni2+ > Co2+ > Mn2+. Accordingly, their behavior followed the Irving-Williams series and Cu2+ ions were preferentially adsorbed from solutions containing metal ion mixtures. The adsorbed ions were easily desorbed from the AmACs by stirring in 0.1 M HCl. 相似文献
912.
Photocatalytic decomposition of NO on titanium oxide thin film photocatalysts prepared by an ionized cluster beam technique 总被引:1,自引:0,他引:1
Masato Takeuchi Hiromi Yamashita Masaya Matsuoka Masakazu Anpo Takashi Hirao Nobuhisa Itoh Nobuya Iwamoto 《Catalysis Letters》2000,66(3):185-187
Transparent TiO2 thin film photocatalysts were prepared on transparent porous Vycor glass (PVG) by an ionized cluster beam (ICB) method. The
UV‐VIS absorption spectra of these films show specific interference fringes, indicating that uniform and transparent TiO2 thin films are formed. The results of XRD measurements indicate that these TiO2 thin films consist of both anatase and rutile structures. UV light (λ > 270 nm) irradiation of these TiO2 thin films in the presence of NO led to the photocatalytic decomposition of NO into N2, O2 and N2O. The reactivity of these TiO2 thin films for the photocatalytic decomposition of NO is strongly dependent on the film thickness, i.e., the thinner the
TiO2 thin films, the higher the reactivity.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
913.
Thermosensitive phase separation of aqueous solutions of the random copolymers of N-isopropylacrylamide (iPA) and N,N-diethylacrylamide (dEA) (PiPA-dEA) and of iPA and N-isopropylmethacrylamide(iPMA) (PiPA-iPMA) with different compositions has been investigated by using calorimetry, turbidimetry and infrared spectroscopy. Though the phase transition temperature (Tp) of PiPA-iPMA is a linear function of its composition, a deviation from additivity is observed for that of PiPA-dEA, that is, it has a minimum value at iPA/dEA = 1 (mol/mol). IR spectrum at the amide II mode of the copolymer suggests that part of N-H groups of iPA units form a hydrogen bond with CO groups of dEA units at T > Tp as well as with those of the iPA units. Effects of methanol on Tp of these copolymers have also been studied. 相似文献
914.
Yoshikazu Yamasaki Masato Goto Akira Kariyasaki Shigeharu Morooka Yoshiko Yamaguchi Masaya Miyazaki Hideaki Maeda 《Korean Journal of Chemical Engineering》2009,26(6):1759-1765
When two immiscible liquids make contact in a microchannel, the flow pattern is affected by the affinity between channel walls
and liquids. In this study, microchannels (200 μm in width and 200 μm in depth) having a T-shaped bifurcation point were fabricated
on PMMA plates. The inner walls of the microchannels were modified in a zone-selective manner to be either hydrophilic or
hydrophobic, based on verification accomplished via a laser interference fringe technique. The microchannel was placed horizontally,
and water and octane were introduced into the upper-side channel (hydrophilic) and into the lower-side channel (hydrophobic),
respectively. The experimental results showed that water and octane formed a stable layered flow, and the two liquids were
virtually completely separated at the T-shaped section, even when static pressure was intentionally applied to the outlets.
CFD simulation, using FLUENT 6.3 software, was performed to explain the role of zone-selective modification of microchannel
walls. 相似文献
915.
When we design a prescribed transfer function T(s) = Q(s)/P(s), the designed circuit surely realize the above T(s) if op-amps are ideal. However due to the above-mentioned frequency characteristics of op-amps there arise higher order terms in the denominator of the transfer function.These parasitic terms have positive or negative sign. Thus in the worst case we cannot cancel a negative term by positive terms because these coefficients are not predictable a priori.When we design the circuit, it is preferable to avoid the circuit which may be potentially unstable. It is therefore preferable to give some criteria for a class of circuit to be potentially unstable.This paper give some topological criteria for an op-amp circuit to be potentially unstable. The criteria is graph-theoretic, but the conclusion is very familiar to active circuit designer. 相似文献
916.
Masato Arai Takanobu Odagiri Osami Yanagisawa Mitsuru Izumi 《Solid-state electronics》2003,47(12):2187
In a perovskite-type chromite La0.5Pr0.5CrO3, we studied the photo-induced electron-spin resonance (ESR). During the illumination of near-infrared light, the photo-induced and transient magnetization is temperature dependent with the characteristic thermal activation energy of 130 meV below the spin-canted antiferromagnetic transition temperature 261 K. At room temperature the photo-induced ESR intensity is remarkably enhanced. We interpret this is coming from the photo-excited electronic state in chromite. By analogy with the manganites, we suspect that the irradiated photons excite the t2g electrons to the eg state in Cr3+ (3d3). This kind of excitation may cause a creation of novel transient magnetic order than canted antiferromagnetism. The present results may open up an intriguing collective photo-induced magnetism, the creation and control of spin and spin-polarization dependent transport with near-infrared light illumination. 相似文献
917.
In this paper, we propose dual-hop non-regenerative Orthogonal Frequency Division Multiplexing (OFDM) relay systems without
signal buffering and processing delay due to Fast Fourier Transform (FFT) and Inverse FFT (IFFT) at the Relay Node (RN). One
scheme uses per subcarrier Power Allocation (PA) at Source Node (SN) and per chunk PA at RN to improve the achievable rate.
Another scheme employs per chunk PA at both SN and RN. Numerical results in mobile communication environments show that both
schemes improve the achievable rates compared to conventional simple amplify-and-forward relay systems with per subcarrier
PA at RN. In particular, the latter scheme can obtain almost the same or slightly higher achievable rates by selecting an
appropriate chunk size in severe frequency selective channel and by setting any chunk size in highly frequency-correlated
channels. Therefore, chunk-based PA at both SN and RN can be found a beneficial PA for dual-hop OFDM relay systems in terms
of competitive achievable rates and relatively small amount of required channel information to calculate allocated power. 相似文献
918.
Masato Sasaki Hirokatsu Umegami Masayoshi Yamamoto 《IEEJ Transactions on Electrical and Electronic Engineering》2016,11(Z2):S144-S145
Silicon carbide schottky barrier diodes (SiC SBDs) have much better characteristic than Si PiN diode in high voltage applications because SiC SBDs do not have recovery effect. However, simple replacing is not the most effective way. In a boost converter, the power loss caused by the SiC SBD can be divided into the conduction loss of the SiC SBD and the loss caused by the energy stored in the junction capacitance of the SiC SBD. Therefore analysis of not only the conduction loss but also the loss caused by the energy stored in the junction capacitance of the SiC SBD can realize the SiC SBD selection to improve the efficiency of the boost converter. © 2016 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献