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81.
Hideo Sawada 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(4):905-912
Abstract A novel correlation for predicting the heat of terpolymerization from the binary data is proposed. This correlation is applicable to the ternary system with monomers which obey the Q-e scheme. The heat of terpolymerization for the ternary system methyl methacrylate-styrene-acrylonitrile is calculated from binary data. 相似文献
82.
Ryugo S. HAYANO Masaharu TSUBOKURA Makoto MIYAZAKI Hideo SATOU Katsumi SATO Shin MASAKI Yu SAKUMA 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2013,89(4):157-163
The Fukushima Dai-ichi NPP accident contaminated the soil of densely-populated regions in Fukushima Prefecture with radioactive cesium, which poses significant risks of internal and external exposure to the residents. If we apply the knowledge of post-Chernobyl accident studies, internal exposures in excess of a few mSv/y would be expected to be frequent in Fukushima.Extensive whole-body-counter surveys (n = 32,811) carried out at the Hirata Central Hospital between October, 2011 and November, 2012, however show that the internal exposure levels of residents are much lower than estimated. In particular, the first sampling-bias-free assessment of the internal exposure of children in the town of Miharu, Fukushima, shows that the 137Cs body burdens of all children (n = 1,383, ages 6–15, covering 95% of children enrolled in town-operated schools) were below the detection limit of 300 Bq/body in the fall of 2012. These results are not conclusive for the prefecture as a whole, but are consistent with results obtained from other municipalities in the prefecture, and with prefectural data. 相似文献
83.
Eriko Sato Noboru Tamari Hideo Horibe 《Journal of polymer science. Part A, Polymer chemistry》2019,57(24):2474-2480
Graft copolymers show microphase separated structure as seen in block copolymers and have lower intrinsic viscosity than block copolymers because of a branching structure. Therefore, considering molding processability, especially for polymers containing rigid segments, graft copolymers are useful architectures. In this work, graft copolymers containing rigid poly(diisopropyl fumarate) (PDiPF) branches were synthesized by full free‐radical polymerization process. First, synthesis of PDiPF macromonomers by addition‐fragmentation chain transfer (AFCT) was investigated. 2,2‐Dimethyl‐4‐methylene‐pentanedioic acid dimethyl ester was found to be an efficient AFCT agent for diisopropyl fumarate (DiPF) polymerization because of the suppression of undesired primary radical termination, which significantly took place when common AFCT agent, methyl 2‐(bromomethyl)acrylate, was used. Copolymerization of PDiPF macromonomer with ethyl acrylate accomplished the generation of the graft copolymer having flexible poly(ethyl acrylate) backbone and rigid PDiPF branches. The graft copolymer showed a microphase separated structure, high transparency, and characteristic thermal properties to PDiPF and poly(ethyl acrylate). © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2474–2480 相似文献
84.
Tatsuhiko Nagao Daichi Yukihira Yoshinori Fujimura Kazunori Saito Katsutoshi Takahashi Daisuke Miura Hiroyuki Wariishi 《Analytica chimica acta》2014
In mass spectrometry (MS)-based metabolomics studies, reference-free identification of metabolites is still a challenging issue. Previously, we demonstrated that the elemental composition (EC) of metabolites could be unambiguously determined using isotopic fine structure, observed by ultrahigh resolution MS, which provided the relative isotopic abundance (RIA) of 13C, 15N, 18O, and 34S. Herein, we evaluated the efficacy of the RIA for determining ECs based on the MS peaks of 20,258 known metabolites. The metabolites were simulated with a ≤25% error in the isotopic peak area to investigate how the error size effect affected the rate of unambiguous determination of the ECs. The simulation indicated that, in combination with reported constraint rules, the RIA led to unambiguous determination of the ECs for more than 90% of the tested metabolites. It was noteworthy that, in positive ion mode, the process could distinguish alkali metal-adduct ions ([M + Na]+ and [M + K]+). However, a significant degradation of the EC determination performance was observed when the method was applied to real metabolomic data (mouse liver extracts analyzed by infusion ESI), because of the influence of noise and bias on the RIA. To achieve ideal performance, as indicated in the simulation, we developed an additional method to compensate for bias on the measured ion intensities. The method improved the performance of the calculation, permitting determination of ECs for 72% of the observed peaks. The proposed method is considered a useful starting point for high-throughput identification of metabolites in metabolomic research. 相似文献
85.
86.
Tae Hee Kim Hyun Mo Lee Hee Soo Park Sung Dong Kim Su Jin Kwon Atsushi Tahara Hideo Nagashima Bun Yeoul Lee 《应用有机金属化学》2019,33(4)
The original Sasol catalytic system for ethylene tetramerization is composed of a Cr source, a PNP ligand, and MAO (methylaluminoxane). The use of expensive MAO in excess has been a critical concern in commercial operation. Many efforts have been made to replace MAO with non‐coordinating anions (e.g., [B(C6F5)4]?); however, most of such attempts were unsuccessful. Herein, an extremely active catalytic system that avoids the use of MAO is presented. The successive addition of two equivalent [H(OEt2)2]+[B(C6F5)4]? and one equivalent CrCl3(THF)3 to (acac)AlEt2 and subsequent treatment with a PNP ligand [CH3(CH2)16]2C(H)N(PPh2)2 ( 1 ) yielded a complex presumably formulated as [ 1 ‐CrAl (acac)Cl3(THF)]2+[B(C6F5)4]?2, which exhibited high activity when combined with iBu3Al (1120 kg/g‐Cr/h; ~4 times that of the original Sasol system composed of Cr (acac)3, iPrN(PPh2)2, and MAO). Via the introduction of bulky trialkylsilyl substituents such as –SiMe3, –Si(nBu)3, or –SiMe2(CH2)7CH3 at the para‐position of phenyl groups in 1 (i.e., by using [CH3(CH2)16]2C(H)N[P(C6H4‐p‐SiR3)2]2 instead of 1 ), the activities were dramatically improved, i.e., tripled (2960–3340 kg/g‐Cr/h; more than 10 times that of the original Sasol system). The generation of significantly less PE (<0.2 wt%) even at a high temperature is another advantage achieved by the introduction of bulky trialkylsilyl substituents. NMR studies and DFT calculations suggest that increase of the steric bulkiness on the alkyl‐N and P‐aryl moieties restrict the free rotation around (alkyl)N–P (aryl) bonds, which may cause the generation of more robust active species in higher proportion, leading to extremely high activity along with the generation of a smaller amount of PE. 相似文献
87.
88.
89.
Abstract Some dicarhoxyphenylphosphonic acids (DCPPA) were prepared by new process. We succeeded in introducing two carhoxyl groups into the phenyl group of phenylphosphonic acid. The dialkyl iso- and tere-phthalate (DACB) were conveniently hrominated with NBS /H2SO4 system to provide the corresponding hromidcs (DACBB) in good yields and good selectivities. 相似文献
90.
Yoshihiro Abe Hideo Hosono Takayuki Kamae Kouichi Kawashima 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):113-116
Abstract Protons in alkaline-earth phosphate glasses give much higher mobility than those in silicate glasses. This is caused by the difference in O-H bonding state. Protons in P-OH form a strong hydrogen bonding with oxygen anion, resulting in formation of weak O-H bond. The electrical conductivity of the glasses is proportional to the square of the proton concentration. The activation energy for the conduction is related to νOH, peak wavenumber of infrared absorption band (around~3000 cm?1), due to fundamental O-H stretching vibration. The mobility of protons increases with decreasing νOH, which depends on the species of ions included in the phosphate glasses. 相似文献