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121.
Roto Himeno Fumitaka Ohashi Tetsuji Kume Erika Asai Takayuki Ban Takatoshi Suzuki Tamio Iida Hitoe Habuchi Yasuo Tsutsumi Hironori Natsuhara Shuichi Nonomura 《Journal of Non》2012,358(17):2138-2140
The optical properties of Si clathrate, which is believed to have potential as a new Si-based material for optical devices, were investigated in this study. Si clathrates with type II structure (NaxSi136) with low Na content (x = 1.3, 2.0) were synthesized by thermal decomposition of NaSi. The synthesized samples were purified by centrifugation using a solution of CH2Br2–C2Cl4 to remove impurities. Using the obtained high purity samples (Na1.3Si136, 93 wt.%; Na2.0Si136, 90 wt.%), the optical absorption spectra of NaxSi136 were clarified, for the first time, from diffuse reflection measurements. The inclusion of Na in Si136 was found to cause free carrier absorption in the infrared region but had little effect on the fundamental absorption edge found in the visible region. 相似文献
122.
Hiroki Kotaka Hiroyoshi Momida Ayuko Kitajou Shigeto Okada Tamio Oguchi 《Chemical record (New York, N.Y.)》2019,19(4):811-816
We study the Na‐ion battery characteristics of SnS as a negative electrode by first‐principles calculations. From energy analyses, we clarify the discharge reaction process of the Na/SnS half‐cell system. We show a phase diagram of Na?Sn?S ternary systems by constructing convex‐hull curves, and show a possible reaction route considering intermediate products in discharge reactions. Voltage‐capacity curves are calculated based on the Na?SnS reaction path that is obtained from the ternary phase diagram. It is found that the conversion reactions and subsequently the alloying reactions proceed in the SnS electrode, contributing to its high capacity compared with the metallic Sn electrode, in which only the alloying reactions progresses stepwise. To verify the calculated reaction process, x‐ray absorption spectra (XAS) are calculated and compared with experimental XAS at S K‐edge, showing meaningful XAS changes associated with Na2S and SnS in discharged and charged states, respectively. 相似文献
123.
Zhe Wang Fei Xue Tamio Hayashi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(32):11170-11173
The one‐step synthesis of arylacetaldehydes by carbon–carbon bond formation between formylmethyl and aryl groups has been realized by the reaction of vinylene carbonate with arylboronic acids in the presence of an iridium/bisphosphine catalyst and a catalytic amount of tetrahydroxydiboron. 相似文献
124.
Tomoki Narita Kouhei Naruse Ikumi Suzuki Shunsuke Ogawa Tamio Iida Norimitsu Yoshida Takashi Itoh Shuichi Nonomura 《Journal of Non》2008,354(19-25):2214-2217
To investigate the deposition of Ge films without toxic gas such as germane, we have studied the Ge films prepared by the hot-wire technique, which utilize the reaction between a Ge target and hydrogen atoms generated by the hot-wire decomposition of H2 gas. The films deposited on Si substrate were microcrystalline Ge films and the mean crystallite size of the films increased from 13.3 to 24.8 nm with increasing the substrate temperature from 300 to 500 °C. Moreover, the deposition rate of Ge films deposited on Si substrate was higher than that of Ge films deposited on Corning 1737 substrate. It was found that the substrate temperature and the kind of substrate are key parameters for the preparation of microcrystalline Ge films by the hot-wire technique. 相似文献
125.
Population inversion on He I is experimentally investigated in a recombining helium plasma. Experimental results confirm that population inversions for n = 3–4 and 3–5 levels of the He I singlet system are larger than for the triplet system. The difference between the two systems is discussed by using rate equations. 相似文献
126.
Tamio Ikeshoji Isao Taniguchi Fred M. Hawkridge 《Journal of Electroanalytical Chemistry》1989,270(1-2)
The biphasic behavior of the formal potential (Eo') of cytochrome c with variations of pH (2.5–9) and temperature (4–52° C) is discussed. From an analysis of the dependence of Eo' on pH and temperature it was found that the biphasic behavior of Eo' is due to ferricytochrome c and not ferrocytochrome c. Four conformational states in ferricytochrome c have been identified from the electrochemical measurements. The linear change in Eo' of the individual states with pH and temperature was explained by a simple equation of the electrode reaction with an apparent protonation number. A pH versus temperature diagram which shows the stable regions of the four states has been obtained. These four states correspond to states that have been suggested by other methods such as spectrophotometry and resonance Raman spectroscopy. Since the biphasic changes of Eo' with pH and temperature were very sharp, a conformational transition instead of a change by an equilibrium reaction was introduced to explaine this feature. The high temperature dependence of Eo' (2 mV K−1) of some states has been explained partly by the concentration dependent effect of protons on the entropy change of the electrode reaction. 相似文献
127.
Hiroto Watanabe Tohru Saitoh Tamio Kamidate Kensaku Haraguchi 《Mikrochimica acta》1992,106(1-2):83-90
A dilute micellar solution of poly(oxyethylene) 4-nonylphenyl ether with oxyethylene units 7.5 (PONPE-7.5) was separated into two phases (aqueous and surfactant phases) at room temperature. The partition constants of several chelating reagents and their metal chelates between the two phases were determined at 293 K and ionic strength 0.1 (NaClO4). The partition constants of the neutral metal chelates depend on the kind of metal ions and were considerably smaller than those expected from the regular solution theory. These facts suggested that the chelates were incorporated into a hydrocarbon environment in the surfactant phase, whereas the chelating reagents were distributed in the poly(oxyethylene) part of PONPE-7.5. A brief review was also presented on the analytical applications to the extraction of metal ions and organic compounds. 相似文献
128.
The substitution of the siloxy group in silyl enol ethers with Grignard reagents to form olefins is accomplished by use of nickel acetylacetonate or phosphine-nickel complexes as catalysts, the stereo- and regiochemistry of coupled olefins depending upon the nature of the catalyst and reaction conditions employed. 相似文献
129.
The extraction technique based on phase separation in aqueous micellar solutions is reviewed. The technique has now been utilized for separation and preconcentration of metal chelates, organic compounds, and proteins. Additionally, the phase behavior of the micellar solutions and recent advances in the phase separation technique are also described. In the extraction of metal chelates, distribution equilibria are considered. In contrast to conventional solvent extraction, the distribution of metal chelates into a condensed surfactant phase (surfactant-rich phase) was dependent on metal ions. Proteins were extractable into the surfactant-rich phase according to their hydrophobicity. The recent use of affinity ligands and water-soluble polymers for controlling extractability of proteins are also introduced. 相似文献
130.
Shintani R Tokunaga N Doi H Hayashi T 《Journal of the American Chemical Society》2004,126(20):6240-6241
A rhodium-catalyzed asymmetric 1,4-addition reaction has been applied to the synthesis of 2-aryl-4-piperidones. While other conventional nucleophiles fail, organozinc reagents have been successfully utilized for the construction of these useful compounds in very good yield and enantiomeric excess. 相似文献