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941.
942.
943.
Toshiyuki Kodaira Masaki Ishikawa Osamu Murata 《Journal of polymer science. Part A, Polymer chemistry》1976,14(5):1107-1115
N-Methyl-N-allylmethacrylamide (MAMA) was synthesized and polymerized with radical initiators, and the structure of poly-MAMA was studied, in order to establish the concept that difunctional monomers having monofunctional counterparts which do not polymerize are likely to give rise to highly cyclized polymer, if the cyclized polymer is in a lower free-energy level than the monomer. The cyclopolymerizability of MAMA was considerably higher than that of N-allylmethacrylamide, which was previously reported, and its monofunctional counterpart can be polymerized. The extent of cyclization of poly-MAMA was about 93%, even in the polymer obtained by bulk polymerization. The repeating units of poly-MAMA consist mainly of five-membered rings; six-membered rings and pendent methacryl groups were detected in addition as minor repeating components. The monofunctional counterparts of MAMA, i.e., N-methyl-N-n-propylmethacrylamide (MPMA) and N-methyl-N-allylisobutyramide (MAIA), were also synthesized. Neither MPMA nor MAIA showed any tendency toward polymerization under the same experimental conditions as used for MAMA. The results thus obtained all support the concept mentioned above. 相似文献
944.
Three types of the novel polymer ligands in which 6,8,15,17-tetramethyl-dibenzo-5,9,14,18-tetraaza-cyclotetradecene (L) is present as an integral part of the polymer backbone have been prepared. These polymer ligands are oligomers whose polymerization degree may be about five. Their complexing abilities and extractabilities for copper(II) and nickel(II) have been investigated. Among the polymer ligands, Poly-L3, which contains triethyleneglycol bis(p-phenylene) group as a linkage group, was found to be an excellent extractant for copper(II). 相似文献
945.
Hsin -Lung Wu Shun -Jin Lin Koichi Funazo Minoru Tanaka Toshiyuki Shono 《Fresenius' Journal of Analytical Chemistry》1985,322(4):409-412
Summary A simple, sensitive and specific method is described for the determination of iodide as pentafluorobenzyl iodide, based on the chemical derivatization of iodide anion with pentafluorobenzyl bromide. The derivative formed in the reaction solution was directly analyzed, without further pretreatment, by gas chromatography with an electroncapture detector. The detection limit was about 1 ng of iodide anion in 0.10 ml of aqueous sample analyzed. Interferences of some common anions with the method were investigated and were proved to be minimal. It was demonstrated that the proposed method is applicable to the determination of iodide in spring water.
Bestimmung von Iodidspuren durch Derivatisierung und Electron-Capture GC
Zusammenfassung Eine einfache, empfindliche und spezifische Methode wird beschrieben zur Iodidbestimmung als Pentafluorbenzyliodid, die auf der Reaktion von Iodid mit Pentafluorbenzylbromid beruht. Das gebildete Derivat wird direkt ohne weitere Vorbehandlung der GC mit Electron-Capture-Detektion unterworfen. Die Nachweisgrenze liegt bei etwa 1 ng Iodid in 0,1 ml. Störungen durch andere Anionen wurden untersucht und erwiesen sich als unbedeutend. Das Verfahren wurde zur Iodidbestimmung in Quellwasser angewendet.相似文献
946.
Toshiyuki Sueyoshi 《The Journal of the Operational Research Society》1990,41(3):249-257
A special algorithm is presented for the additive model in data envelopment analysis (DEA). The special algorithm first classifies a data set into several subsets. Then the subset is solved by a different algorithmic framework. In simulation studies, the algorithm outperformed available DEA codes. The proposed algorithm can efficiently deal with a large data set. 相似文献
947.
An improved entry to a key thienamycin intermediate is described which relies upon the direct epimerization at C-3 of the 3-(1-hydroxyethyl)-2-azetidinone derivatives readily obtained from methyl ()-3-hydroxybutanoate. 相似文献
948.
Takahiro Hosokawa Toshiyuki Ohta Yoshihiro Okamoto Shun-Ichi Murahashi 《Tetrahedron letters》1980,21(13):1259-1260
Methylene dioximes are formed from ketoximes and CH2Cl2 using either KO2 with a catalytic amount of Pd(II) complex or K2CO3 with 18-crown-6 catalyst. The reactivity of ketoximes towards CH2Cl2 is reversed between these two methods. 相似文献
949.
A new type of liquid crystalline polyesters with resorcin as one part of the mesogenic unitconnected together by polymethylene, or phenylene group, and lateral groups consisting of arigid azobenzene as another part of the mesogenic unit were synthesized by interfacialpolymerization of diacyl chlorides in 1, 2-dichloroethane and 2, 4-dihydroxy-4'-nitroazobenzen inaqueous alkaline solution. The polyester structures were confirmed by proton NMR and IRspectra. Their phase transition behavior and texture were studied by polarizing microscopy andDSC. 相似文献