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81.
The microstructure of ion-exchange resins has been investigated to understand more clearly the ion-exchange mechanism. Nine types of resins with different pore structures were used: all of the polystyrene family crosslinked with divinylbenzene and anionic resins, with mesh sizes ranging from 100 to 200, except for one (20–50 mesh). Various pore volumes of each resin were determined by measurements of intrusion of some chemical species (H2O, Nd3+, and Hg) into the resin. The results are analyzed on the basis that an ion-exchange resin particle consists of four regions. They are: 1) the mercury intrusion region, 2) the region where coions (such as Nd3+) can intrude but mercury cannot, 3) the region where water or counterions can intrude but coions cannot, and 4) the polymer matrix region occupied by the polymer skeleton. The former two regions are not influenced by the resin-fixed ionic groups. While it used to be thought that specific adsorption of counterions may occur in the entire exchange resin particle, it is appropriate to consider that specific adsorption takes place only in the latter two regions. According to this point of view, the adsorption equilibrium of the Fe3+/Cl? complex ions could be explained more satisfactorily. 相似文献
82.
83.
Susumu Kuwamura Yasuyuki Azuma Noriaki Miura Fumiaki Tsumuraya Makoto Sakamoto Naoshi Baba 《Optical Review》2014,21(1):9-16
In astronomical speckle imaging, deconvolving a shift-and-add (SAA) image has an advantage over deconvolving noisy specklegrams, because an SAA image is an integration of many specklegrams and has a relatively enhanced signal-tonoise ratio. In this paper, to reinforce the deconvolution of a single SAA image, we propose a multiframe deconvolution applied to multiple SAA images that are obtained by diversely recombining the same set of specklegrams to have different point spread functions. We have found that such diverse SAA images can be easily produced by permuting specklegrams to be processed by SAA. The results of experiments using simulated and observational data have shown a robustness of our present approach: in the previous approach of deconvolving a single SAA frame, the resulting object estimate is apt to be influenced by the given SAA frame and the estimation sometimes fails, whereas in the present approach, a reliable object image is stably reconstructed regardless of the given SAA frames. 相似文献
84.
Kamimura A Ishikawa S Noguchi F Moriyama T So M Murafuji T Uno H 《Chemical communications (Cambridge, England)》2012,48(52):6592-6594
Optically active stannolanes and trigonal bipyramidal pentacoordinated tin complexes were readily prepared by radical cyclization of N-propargylated chiral aza-Morita-Baylis-Hillman adducts induced by Bu(3)SnH. A translocated radical through the cyclization attacked the Bu(3)Sn group in an S(H)2 manner. 相似文献
85.
Amano Fumiaki Tian Min Ohtani Bunsho Chen Aicheng 《Journal of Solid State Electrochemistry》2012,16(5):1965-1973
The control of anisotropic crystal growth is critical for directing the orientation of crystal lattice planes, and it plays
a key role towards understanding the effects of different planes on chemical reactions. Here, we report on the photoelectrochemical
properties of plate-structured tungsten trioxide (WO3) thin films prepared from facet-controlled rectangular platelets of hydrotungstite (WO3·2H2O) and tungstite (WO3·H2O), which are directly grown on tungsten substrates. The WO3 thin films, prepared via WO3·2H2O platelets, show relatively stable current for photoelectrochemical water splitting and methanol oxidation. On the other
hand, the photocurrent of the WO3 thin films prepared via WO3·H2O platelets was significantly decreased during the photoelectrochemical oxidation of water, which is likely due to the accumulation
of partially oxidized intermediates such as peroxo species on the surface. These results indicate that the surface nanostructures
of WO3 may have a significant influence on photoelectrode efficiency and selectivity for the catalytic oxygen evolution reaction. 相似文献
86.
Kisa F Yamada K Miyamoto T Inagaki M Higuchi R 《Chemical & pharmaceutical bulletin》2006,54(7):982-987
Three new monosialo-gangliosides, CEG-3 (3), CEG-4 (4), and CEG-5 (5), were obtained, together with two known gangliosides, SJG-1 (1) and CG-1 (2), from the lipid fraction of the chloroform/methanol extract of the sea cucumber Cucumaria echinata. The structures of the new gangliosides were determined on the basis of chemical and spectroscopic evidence to be 1-O-[4-O-acetyl-alpha-L-fucopyranosyl-(1-->11)-(N-glycolyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (3) and 1-O-[alpha-L-fucopyranosyl-(1-->11)-(N-glycolyl-alpha-D-neuraminosyl)-(2-->6)-beta-D-glucopyranosyl]-ceramide (4, 5). The ceramide moieties of each compound were composed of heterogeneous sphingosine or phytosphingosine bases, and 2-hydroxy or nonhydroxylated fatty acid units. These gangliosides showed neuritogenic activity toward the rat pheochromocytoma cell line PC-12 in the presence of nerve growth factor. 相似文献
87.
Kozo Matsumoto Fumiaki Ozaki Hideki Matsuoka 《Journal of polymer science. Part A, Polymer chemistry》2008,46(13):4479-4485
Diblock copolymer membranes having a fluorinated segment and a sulfonic acid segment were prepared by living radical polymerization, solution casting, and crosslinking, followed by heat treatment. Diblock copolymers of 2,3,4,5,6‐pentafluorostyrene (PFS)/4‐(1‐methylsilacyclobutyl)styrene (SBS) and neopentyl styrenesulfonate (SSPen) (poly(PFS‐co‐SBS)‐b‐polySSPen)s were synthesized by nitoroxy‐mediated living radical polymerization. Self‐standing crosslinked membranes were obtained by casting a THF solution of the block copolymer with Pt catalyst. Heat treatment of the membrane at 230 °C induced decomposition of the neopentyl sulfonate esters to provide block copolymer membranes having a fluorinated segment and a free sulfonic acid segment. It was confirmed that the block copolymer with a high sulfonic acid content exhibited high ion exchange capacity and high proton conductivity as well as high thermal stability. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4479–4485, 2008 相似文献
88.
Shuji Machihara 《NoDEA : Nonlinear Differential Equations and Applications》2007,14(5-6):625-641
The Cauchy problem for the Dirac–Klein–Gordon equation are discussed in one space dimension. Time local and global existence
for solutions with rough data, especially the solutions for Klein–Gordon equation in the critical and super critical Sobolev
norm of [4] are considered. The solutions with general propagation speeds are dealt with.
相似文献
89.
Fumiaki Kira 《Optics Communications》2006,265(2):603-606
The third harmonic emission (261 nm, 30 μJ) of a femtosecond Ti:sapphire laser is focused into molecular hydrogen to generate vibrational stimulated Raman emission. High-order emission lines are efficiently generated by using a high-beam-quality nearly-transform-limited laser and high-pressure hydrogen (40 atm) as a Raman medium. 相似文献
90.
Daisuke Kawaguchi Ayumi Kodama Naoko Abe Kei Takebuchi Fumitaka Hashiya Fumiaki Tomoike Kosuke Nakamoto Yasuaki Kimura Yoshihiro Shimizu Hiroshi Abe 《Angewandte Chemie (International ed. in English)》2020,59(40):17403-17407
Messenger RNAs (mRNAs) with phosphorothioate modification (PS‐mRNA) to the phosphate site of A, G, C, and U with all 16 possible combinations were prepared, and the translation reaction was evaluated using an E. coli cell‐free translation system. Protein synthesis from PS‐mRNA increased in 12 of 15 patterns when compared with that of unmodified mRNA. The protein yield increased 22‐fold when the phosphorothioate modification at A/C sites was introduced into the region from the 5′‐end to the initiation codon. Single‐turnover analysis of PS‐mRNA translation showed that phosphorothioate modification increases the number of translating ribosomes, thus suggesting that the rate of translation initiation (rate of ribosome complex formation) is positively affected by the modification. The method provides a new strategy for improving translation by using non‐natural mRNA. 相似文献