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排序方式: 共有172条查询结果,搜索用时 15 毫秒
1.
Atiya MS Chiang I Frank JS Haggerty JS Ito MM Kycia TF Li KK Littenberg LS Stevens A Strand RC Louis WC Akerib DS Marlow DR Meyers PD Selen MA Shoemaker FC Smith AJ Azuelos G Blackmore EW Bryman DA Felawka L Kitching P Kuno Y Macdonald JA Numao T Padley P Poutissou J Poutissou R Roy J 《Physical review letters》1990,65(1):21-24
2.
C. G. Degiacomi A. Holenstein F. K. Kneubühl D. Huguenin 《International Journal of Infrared and Millimeter Waves》1990,11(1):55-59
We have designed and built a balloon-borne far-infrared 60 cm telescope equipped with He-cooled filters and a composite silicon bolometer with an NEP of 1.3·10–14 W/Hz1/2 for imaging, radiometry and spectroscopy of the Cygnus region at wavelengths up to 330 m. A test flight took place at the CNES balloon station at Aire/Adour, F, on May 8, 1989. The balloon stayed 41/2 h at the observation height of 39 km. Tests and results are discussed. 相似文献
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Kenji Yokota Hideo Tomioka Teruyuki Ono Fumimasa Kuno 《Journal of polymer science. Part A, Polymer chemistry》1972,10(5):1335-1343
The sensitization effect of tertiary amines on the photopolymerization of methyl methacrylate was studied. N,N-Dimethylbenzylamine, triethylamine, and N,N-dimethylaniline increased the rate of polymerization in this order, but pyridine did not show any effect. A free-radical mechanism was confirmed by the tacticity of polymer, the retarding effect of hydroquinone, and the copolymer composition with styrene. On the basis of the detailed kinetics of the sensitized polymerization and the ultraviolet spectra of the reaction mixtures, a sensitization mechanism is proposed, in which the excited monomer and the amine form a complex and generate an initiating radical. 相似文献
5.
Kuno Wagner Kurt Findeisen Walter Schfer Werner Dietrich 《Angewandte Chemie (International ed. in English)》1981,20(10):819-830
Research in the field of low-molecular weight, oligomeric and polymeric α,ω-diisocyanatocarbodiimides and -polycarbodiimides has been fruitful, not only in connection with these compounds themselves, but also—as so often happens in chemistry—with quite different problems. Novel synthetic methods, discoveries concerning the properties of low-molecular weight carbodiimides and phosphane imide derivatives, as well as results on the fragmentation reactions of four-membered heterocyclic compounds containing oxygen, phosphorus, and nitrogen, and a better understanding of the diisocyanate polyaddition process are among the many by-products of this research. The “high- and low-temperature formation” of polycarbodiimides and the homogeneous and heterogeneous catalysis of this process are described, and the fundamental importance of four-membered ring fragmentation mechanisms resulting in the formation of phosphane imide derivatives is outlined. Interesting building blocks for the diisocyanate polyaddition and polycondensation processes can be synthesized by many derivatization reactions of oligomeric and high-molecular weight polycarbodiimides and polyuretonimines. The in situ production of polycarbodiimides via matrix reactions in flexible polyurethane foams leads to a cellular arrangement of the material due to the pronounced symmetrical growth processes. Combination-foams with increased carbonation tendencies are formed in this way. Attention is drawn to several industrial applications of α,ω-diisocyanatopolycarbodiimides, of high-molecular weight cross-linked polyuretonimines, and of polycarbodiimide foams. 相似文献
6.
A Kuno Y Sugiyama K Katsuta T Kamitani H Takasugi 《Chemical & pharmaceutical bulletin》1992,40(6):1452-1461
Novel 4-arylpyrimidine derivatives were synthesized by the oxidation of 4-aryl-1,4-dihydropyrimidines, and their effects on anti-anoxic (AA) activity in mice and anti-lipid peroxidation (ALP) activity in rat brain mitochondria were investigated. Among these compounds, ethyl 6-methyl-2-phenyl-4-(4-pyridyl)-5-pyrimidinecarboxylate (4b) has AA activity (10 mg/kg, i.p.) and ethyl 6-methyl-4-(3-nitrophenyl)-2-phenyl-5-pyrimidinecarboxylate (4f) has ALP activity (73% inhibition at 10(-5) g/ml). The latter compound (100 mg/kg, i.p.) was also effective on arachidonate-induced cerebral edema in rats with comparable potency to that of vitamin E. 相似文献
7.
Atiya MS Chiang IH Frank JS Haggerty JS Ito MM Kycia TF Li KK Littenberg LS Sambamurti A Stevens A Strand RC Louis WC Akerib DS Marlow DR Meyers PD Selen MA Shoemaker FC Smith AJ Blackmore EW Bryman DA Felawka L Kitching P Konaka A Kuno Y Macdonald JA Numao T Padley P Poutissou JM Poutissou R Roy J Soluk R Turcot AS 《Physical review letters》1993,70(17):2521-2524
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Versatile procedures for the preparation of the title compounds are described. Representatives of ketones ( 12 and 27 ), hydrocarbons ( 19 and 28 ), acids ( 13 ), esters ( 15 . and 20 ), ethers ( 22 ) and nitriles ( 18 ) possess wide-range nematic phases, provided their terminal chains R2 and R3 contain at least three methylene units. 相似文献
10.
Koji Konomi He-Sheng Li† Norihito Kuno Masaki Furuya‡ 《Photochemistry and photobiology》1993,58(6):852-857
Abstract Treatment of imbibed embryonic axes taken from seeds of Pisum sativum with N-phenylimide S-23142, a herbicide that has been suggested to inhibit protoporphyrin synthesis, or with N -methyl mesoporphyrin IX, an inhibitor of the iron chelatase for heme, resulted in a significant decrease in the amount of spectrophotometrically detectable phytochromc in the axes in both cases. However, the amount of immunochemically detectable phytochrome was not affected by either treatment. If S-23142 inhibits the synthesis of protoporphyrin IX in pea, it appears that the conversion of protoporphyrinogen IX to protoporphyrin IX is involved in the biosynthesis of the phytochrome chromophore. The conversion of protoporphyrin IX to heme (Fe-protoporpbyrin) also appears to be a step in the biosynthesis of the chromophore, since N -methyl mesoporphyrin IX prevented the synthesis of spectrophotometrically detectable phytochrome but did not affect the magnesium chelatase activity required for the synthesis of chlorophyll in pea embryonic axes. The results suggest that protoporphyrinogen IX, protoporphyrin IX and heme are intermediates in the biogenesis of the phytochromc chromophore. The pathway to phytochromobilin might become fixed after protoporphyrin IX, being directed toward the Fe branch for heme rather than to the Mg branch for chlorophyll. 相似文献