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991.
Nobumasa Kamigata Takeshi Ohtsuka Toshio Shimizu 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):491-492
Abstract Regioselective perfluoroalkylation of heteroaromatic compounds by perfluoroalkanesulfonyl chloride in the presence of a catalytic amount of ruthenium(II) phosphine complex is described. 相似文献
992.
Yanming Hu Toshiyuki Shimizu Kyohei Hattori Masashi Shiotsuki Fumio Sanda Toshio Masuda 《Journal of polymer science. Part A, Polymer chemistry》2010,48(4):861-868
Diarylacetylene monomers containing substituted biphenyl ( 1a – f ) and anthryl ( 1g ) groups were synthesized and then polymerized with TaCl5‐n‐Bu4Sn catalyst to produce the corresponding poly(diarylacetylene)s ( 2a – g ). Polymers 2a – f were soluble in common organic solvents such as cyclohexane, toluene, and chloroform. According to thermogravimetric analysis, the onset temperatures of weight loss of the polymers were over 400 °C in air, indicating considerably high thermal stability. Free‐standing membranes 2a and 2c – e were prepared by the solution casting method. Desilylation of Si‐containing membrane 2c was carried out with trifluoroacetic acid to afford 3c . All the polymer membranes, especially those having twisted biphenyl groups, exhibited high gas permeability; for example, their oxygen permeability (PO 2) values ranged from 130 to 1400 barrers. Membrane 2d having two chlorine atoms in the biphenyl group showed the highest gas permeability (PO 2 = 1400 barrers) among the present polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 861–868, 2010 相似文献
993.
Yoshitaka Shimizu Yoko Ohte Xinnu Bao Satoko Otsuka Yuko Kitamaki Keiichiro Ishikawa Toshihide Ihara Kenji Kato 《Accreditation and quality assurance》2008,13(7):389-396
For accurate measurement of concentrations of substances by instrumental analysis, reliable calibration standards are needed.
In Japan, national reference materials are supplied under the national standards dissemination system named the Japan Calibration
Service System (JCSS). In JCSS, calibration standards for the analysis of environmental pollutants are supplied. For the traceability
to the SI of reference materials for calibration in JCSS, the National Metrology Institute of Japan (NMIJ) is developing high-purity
reference materials of volatile organic compounds (VOCs) as NMIJ CRMs. The freezing-point depression method, which has potential
as a primary method of measurement, is employed for the determination of property value. In this paper, a development scheme
of certified reference materials of high-purity VOCs is described.
Presented at BERM-11, October 2007, Tsukuba, Japan. 相似文献
994.
995.
996.
The determination of trace amounts of boron in steel by reversed-phase high-performance liquid chromatography (HPLC) is described. As a derivatizing reagent for the HPLC determination of boron, 8-hydroxy-1-(salicylideneamino)-3,6-naphtalenedisulfonic acid (azomethine-H) was used with a spectrophotometric detection. A peak of boron-azomethine-H chelate was resolved from other peaks using an acetonitrile-water (29 + 71 m/m) eluent containing 8 x 10(-3) mol kg(-1) tetrabutylammonium bromide and 5 x 10(-3) mol kg(-1) acetate buffer (pH 5.0). The lower determination limit (10sigma) of boron was 3.3 x 10(-8) mol dm(-3) for a solution injected into HPLC, which is translated to 0.09 microgB/g when 0.1 g of a steel sample was subjected to the analysis. The analytical results of certified steel samples were in good agreement with the guaranteed values. The addition of ethylenediamine-N,N,N',N'-tetraacetate as a masking agent for the iron(III) matrix with the optimized eluent enables one to achieve the direct determination of trace amounts of boron in such steel sample solutions without any tedious matrix removal or preconcentration. 相似文献
997.
998.
Kazuki Aoyama Kunio Shimizu S. H. Ong 《Annals of the Institute of Statistical Mathematics》2008,60(1):1-20
In this paper a univariate discrete distribution, denoted by GIT, is proposed as a generalization of the shifted inverse trinomial
distribution, and is formulated as a first-passage time distribution of a modified random walk on the half-plane with five
transition probabilities. In contrast, the inverse trinomial arises as a random walk on the real line with three transition
probabilities. The probability mass function (pmf) is expressible in terms of the Gauss hypergeometric function and this offers
computational advantage due to its recurrence formula. The descending factorial moment is also obtained. The GIT contains
twenty-two possible distributions in total. Special cases include the binomial, negative binomial, shifted negative binomial,
shifted inverse binomial or, equivalently, lost-games, and shifted inverse trinomial distributions. A subclass GIT3,1 is a particular member of Kemp’s class of convolution of pseudo-binomial variables and its properties such as reproductivity,
formulation, pmf, moments, index of dispersion, and approximations are studied in detail. Compound or generalized (stopped
sum) distributions provide inflated models. The inflated GIT3,1 extends Minkova’s inflated-parameter binomial and negative binomial. A bivariate model which has the GIT as a marginal distribution
is also proposed. 相似文献
999.
1000.
T. Danno H. Matsumoto M. Nasir S. Shimizu M. Minagawa J. Kawaguchi H. Horibe A. Tanioka 《Journal of Polymer Science.Polymer Physics》2008,46(6):558-563
The fine structure of poly(vinylidene fluoride) (PVDF) nanofiber prepared by electrospray deposition (ESD) has been investigated by wide angle X‐ray diffraction (WAXD) and infrared spectroscopy (IR). The β‐phase crystal was dominant in the crystalline region. The degree of crystallinity of 0.54 for the nanofiber, determined by Ruland's method, was almost identical to that for a melt pressed sheet of PVDF. The disorder parameter k was 4, which is significantly smaller than the value of 6 for the melt pressed sheet of PVDF. Molecular orientation along the fiber axis was observed by the polarized infrared spectra of the uniaxially aligned nanofiber. These results suggest that the PVDF nanofiber possesses a fiber structure which is by no means inferior to that of practical fibers. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 558–563, 2008 相似文献