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131.
Seiji Yamaguchi Eriko Hamade Hajime Yokoyama Yoshiro Hirai Shunsaku Shiotani 《Journal of heterocyclic chemistry》2002,39(2):335-339
Birch reduction of four furopyridines 1a‐d effected the characteristic cleavage of the furan ring, giving ethnylpyridinols 2a‐d , vinylpyridinols 3b,d , and ethylpyridinols 4a‐d , and the reduction of the furan ring, giving dihydrofuropyridine 5c,d. 相似文献
132.
Hidehito Nanto Fumitaka Endo Yoshiaki Hirai Shouichi Nasu Nozomu Takeuchi 《Optical Review》1994,1(2):177-179
Intense photostimulated luminescence (PSL) with a peak at 420 nm is observed in ultraviolet (UV) Iight-irradiated europium-doped potassium chloride (KCl: Eu) crystalline phosphors. The PSL characteristics of UV-irradiated KCl: Eu phosphor for optical memory application were studied. The excitation and emission mechanisms of the 420 nm PSL, which are consistent with the results obtained, are discussed. 相似文献
133.
Ram Sharma Tiwaree Kyeoung-scik Cho Mitsgyo Hirai Makoto Shoda 《Applied biochemistry and biotechnology》1992,32(1-3):135-148
Biological deodorization of dimethyl sulfide (DMS) was studied using nine unwoven fabrics as the carriers of microorganisms in a laboratory-scale deodorizing system. The activated carbon fabric FN-200CF-15 was the best packing material compared with other packing materials used, on the basis of removal rate. The maximum removal rate (Vm), evaluated by using Michaelis-Menten equation, was 2.28 g-Skg-dry fab.-1 day-1 in this fabric biofilter. The critical load of DMS in this fabric biofilter was dependent on space velocity (SV), determined as 0.78 and 0.66 g-Skg-dry fab.-1 at SV 100 and 150 h-1, respectively. Strain IM1 isolated from the carbon fabric FN-200CF-15 biofilter in modified Waksman (MW) medium successfully degraded DMS as well as hydrogen sulfide (H2S), methanethiol (MT), and dimethyl disulfide (DMDS) in batch test. The DMS removal rates (g-S cell-1h-1) by this strain measured in batch culture and calculated in FN-200CF-15 biofilter by the cell numbers appeared in MW medium were found almost equal, indicating that strain IM1 may be the dominant microorganism in this biofilter. 相似文献
134.
135.
Yasuhiro Shiraishi Yugo Furubayashi Go Nishimura Takayuki Hirai 《Journal of luminescence》2007,127(2):623-632
Dinuclear lanthanide (Ln=Tb3+ or Eu3+) complexes (Ln2L2) of two octadentate macrocyclic polyaminopolycarboxylic ligands connected through a benzophenone (BP) moiety (L2) have been synthesized. Sensitized luminescence properties of Ln2L2 in water have been studied in comparison to those of BP-conjugated mononuclear Ln complexes (LnL1). The luminescence intensity of Tb2L2 is lower than that of TbL1 because of lower triplet quantum yield of the BP moiety. In contrast, Eu2L2 shows higher intensity than EuL1. For both Eu complexes, energy level of triplet excited-state BP (3BP*) is only 3 kJ mol−1 higher than that of 5D2 excited-state of Eu3+. The 5D2 state formed by a triplet-energy transfer (TET) from 3BP* is therefore deactivated by a back energy transfer (BET) to the ground-state BP, resulting in low luminescence intensity of EuL1. In contrast, within Eu2L2, TET from 3BP* to 5D0 state of two Eu3+ ions is accelerated, thus leading to higher luminescence intensity. Another notable feature of Eu2L2 is the luminescence quantum yield independent of its concentration. In contrast, for EuL1 system, an intermolecular BET occurs from 5D2 state of Eu3+ to the ground-state BP conjugated to another EuL1 complex, resulting in a yield decrease with the concentration increase. 相似文献
136.
Hiroki Hirai Kiichi Nakajima Soichiro Nakatsuka Kazushi Shiren Jingping Ni Shintaro Nomura Toshiaki Ikuta Takuji Hatakeyama 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(46):13785-13789
The development of a one‐step borylation of 1,3‐diaryloxybenzenes, yielding novel boron‐containing polycyclic aromatic compounds, is reported. The resulting boron‐containing compounds possess high singlet‐triplet excitation energies as a result of localized frontier molecular orbitals induced by boron and oxygen. Using these compounds as a host material, we successfully prepared phosphorescent organic light‐emitting diodes exhibiting high efficiency and adequate lifetimes. Moreover, using the present one‐step borylation, we succeeded in the synthesis of an efficient, thermally activated delayed fluorescence emitter and boron‐fused benzo[6]helicene. 相似文献
137.
138.
A Novel Synthesis of Quinazolines by Cyclization of 1‐(2‐Isocyanophenyl)alkylideneamines Generated by the Treatment of 2‐(1‐Azidoalkyl)phenyl Isocyanides with NaH
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A new and efficient method for the synthesis of quinazolines has been developed. Thus, N‐[2‐(1‐azidoalkyl)phenyl]formamides 1 are dehydrated with POCl3 to give the corresponding 2‐(1‐azidoalkyl)phenyl isocyanides 2 , which are then treated with NaH in DMF at 0° to give quinazolines 6 in satisfactory yields via cyclization of 1‐(2‐isocyanophenyl)alkylideneamine intermediates 4 . This methodology can be applied to the synthesis of the 7‐azaanalogs of quinazolines, i.e., pyrido[3,4‐d]pyrimidines 9 . 相似文献
139.
Tsukamoto D Ikeda M Shiraishi Y Hara T Ichikuni N Tanaka S Hirai T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(35):9816-9824
Semiconductor TiO2 particles loaded with WO3 (WO3/TiO2), synthesized by impregnation of tungstic acid followed by calcination, were used for photocatalytic oxidation of alcohols in water with molecular oxygen under irradiation at λ>350 nm. The WO3/TiO2 catalysts promote selective oxidation of alcohols to aldehydes and show higher catalytic activity than pure TiO2. In particular, a catalyst loading 7.6 wt % WO3 led to higher aldehyde selectivity than previously reported photocatalytic systems. The high aldehyde selectivity arises because subsequent photocatalytic decomposition of the formed aldehyde is suppressed on the catalyst. The TiO2 surface of the catalyst, which is active for oxidation, is partially coated by the WO3 layer, which leads to a decrease in the amount of formed aldehyde adsorbed on the TiO2 surface. This suppresses subsequent decomposition of the aldehyde on the TiO2 surface and results in high aldehyde selectivity. The WO3/TiO2 catalyst can selectively oxidize various aromatic alcohols and is reusable without loss of catalytic activity or selectivity. 相似文献
140.
Akiyama H Sakata K Makiyma D Nakamura K Teshima R Nakashima A Ogawa A Yamagishi T Futo S Oguchi T Mano J Kitta K 《Journal of AOAC International》2011,94(5):1540-1547
In many countries, the labeling of grains, feed, and foodstuff is mandatory if the genetically modified (GM) organism content exceeds a certain level of approved GM varieties. We previously developed an individual kernel detection system consisting of grinding individual kernels, DNA extraction from the individually ground kernels, GM detection using multiplex real-time PCR, and GM event detection using multiplex qualitative PCR to analyze the precise commingling level and varieties of GM maize in real sample grains. We performed the interlaboratory study of the DNA extraction with multiple ground samples, multiplex real-time PCR detection, and multiplex qualitative PCR detection to evaluate its applicability, practicality, and ruggedness for the individual kernel detection system of GM maize. DNA extraction with multiple ground samples, multiplex real-time PCR, and multiplex qualitative PCR were evaluated by five laboratories in Japan, and all results from these laboratories were consistent with the expected results in terms of the commingling level and event analysis. Thus, the DNA extraction with multiple ground samples, multiplex real-time PCR, and multiplex qualitative PCR for the individual kernel detection system is applicable and practicable in a laboratory to regulate the commingling level of GM maize grain for GM samples, including stacked GM maize. 相似文献