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61.
Shizuko Hirata Yukimasa Hashimoto Masato Aihara G. Vitharana Mallika 《Fresenius' Journal of Analytical Chemistry》1996,355(5-6):676-679
A flow-injection method for the determination of dissolved cobalt(II) in sea water has been studied based on a combination of column preconcentration using 8-quinolinol immobilized on silica gel, fluoride containing metal alkoxide glass (8HQ-MAF) and chemiluminescence detection with a gallic acid-hydrogen peroxide system. Co(II) is selectively recovered from an acidified sample with 8-quinolinol immobilized on silica gel. After elution with dilute hydrochloric acid the resultant eluent is mixed with the reagent solutions, heated to 60°C and then introduced into the CL cell. The analysis time including the 2-min sample load was 8 min per sea water sample with a corresponding detection limit of 0.62 ngl-1 (3). The average standard deviation calculated for 10 replicate measurements of artificial sea water samples with a concentration of 10 ngl-1 cobalt was ±2.1%. The method has been tested with the standard reference sea waters NASS and CASS. 相似文献
62.
Yoshitake Hashimoto 《Communications in Mathematical Physics》1993,151(3):481-485
We give the correspondence between instantons onS
4 and some representations of an associative algebra. For the given structure group, we get simultaneous imbeddings to (the inductive limit) of the moduli spaces for instantons onS
4 of all instanton numbers. 相似文献
63.
Hisahiro Hagiwara Fumihide TakeuchiTakashi Hoshi Toshio SuzukiToshihiro Hashimoto Yoshinori Asakawa 《Tetrahedron letters》2003,44(11):2305-2306
1,9-Dideoxyforskolin 2 has been synthesized starting from ptychantin A 3. 相似文献
64.
4-Fluorinated UDP-MurNAc pentapeptide, 2, has been synthesized. In our previous study, UDP-MurNAc pentapeptide analogue 1 was found to be incorporated into the bacterial cell wall through biosynthesis. Compound 2 showed growth-inhibition activity against Gram-positive bacteria when it was added to growth media at 0.01 mg/mL. [structure--see text] 相似文献
65.
Michiko Iwamura Yuka Gotoh Tomoyuki Hashimoto Reiko Sakurai 《Tetrahedron letters》2005,46(37):6275-6277
Michael addition reactions of acetoacetates and malonates with acrylates in a 5 M KOH aqueous solution without using any other catalysts are described. When they are either tert-butyl or benzyl esters, the reaction proceeded very rapidly to afford moderate to high yields of the corresponding bis-Michael adducts that are unexpectedly stable under these conditions. 相似文献
66.
67.
Yen-Yuan Chen Ryuichi Oshima Kenichi Hatanaka Toshiyuki Uryu 《Journal of polymer science. Part A, Polymer chemistry》1986,24(7):1539-1550
We report herein studies of grafting of MMA onto (1 → 5)-α-D -ribofuranan and (1 → 5)-α-D -xylofuranan by ceric ion initiation both in water and in dimethyl sulfoxide (DMSO). In aqueous medium, the graft polymer having high grafting (%) can be obtained easily without adding any nitric acid. The degradation of polysaccharide by the acidic ceric ion solution is not serious; 73–82% of its original molecular weight remained after the polymerization. In DMSO, graft polymers having lower grafting (%) and lower molecular weight of grafts were obtained. 相似文献
68.
Tsutomu Kagiya Masatsugu Izu Masakazu Hatta Takehisa Matsuda Kenichi Fukui 《Journal of polymer science. Part A, Polymer chemistry》1967,5(5):1129-1135
N,N′-Dipropionylethylenediamine was synthesized by the ring-opening addition reaction of 2-ethyl-2-imidazoline with propionic acid at 220°C. By applying this reaction to polymerization, polyamides were synthesized by the ring-opening polyaddition reaction at 220°C. of 1,4-bis(imidazoline-2-yl)butane with adipic acid, succinic acid, sebacic acid, and terephthalic acid. The reaction product of 1,4-bis(imidazoline-2-yl)butane with adipic acid, which was proposed to be nylon 26, was compared with an authentic sample of nylon 26 and shown to possess a very similar infrared spectrum and melting point. 相似文献
69.
Singlet oxygen was generated by reaction of sodium hypochlorite and hydrogen peroxide in a micro-channel. The two reagent solutions were delivered into the micro-channel by a syringe pump, providing a laminar flow liquid-liquid interface. The chemiluminescence from the singlet oxygen was emitted in the collapse of the interface due to molecular diffusion under laminar flow conditions. The chemiluminescence intensity was observed continuously and stably for each combination of reagents fed into the micro-channel; while, in the normal batch-type reactor the chemiluminescence peaks from singlet oxygen were observed within ca. 5 s. The features of the chemiluminescence emitted under laminar flow conditions were examined by changing the concentrations of sodium hypochlorite and hydrogen peroxide; the concentrations of 2.5 mM sodium hypochlorite and 7.5 mM hydrogen peroxide provided highest chemiluminescence intensities without bubble formation. Also, the effects of beverages, such as green tea, coffee, white wine, red wine, and sake (rice wine), on the chemiluminescence intensity as well as the concentrations of sodium hypochlorite and hydrogen peroxide were examined. The chemiluminescence intensities observed with addition of the beverages to the reagents decreased in the following orders; green tea > coffee > red wine > rice wine > white wine (being added to sodium hypochlorite); coffee > white wine > green tea > red wine > rice wine (being added to hydrogen peroxide). It was found that coffee decreased the chemiluminescence intensity (ca. 33% chemiluminescence decrease) without altering the concentrations of sodium hypochlorite or hydrogen peroxide. The cause of the decrease in chemiluminescence with coffee is discussed. 相似文献
70.
Katsufumi Hashimoto Jií íek Josef Paldus 《International journal of quantum chemistry》1988,34(5):407-415
The ground state energies of finite Hubbard molecules are calculated by numerically solving the Lieb–Wu equations for a complex Hubbard repulsion parameter U. From the positions of the singular points located in the complex plane, the radii of convergence of the perturbation expansions for the ground state energies are determined. 相似文献