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211.
The reactions of furan and a number of its derivatives (furfural, furan-2-carboxylic acid, 2-furfuryl alcohol, and others), in systems containing H2O2 and vanadium compounds, proceed through a mechanism of radical hydoxylation of the furan ring with the formation of 5-hydroxy-2(5H)-furanone and maleic acid. The total yield and ratio of the synthesized compounds depend on the reaction conditions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1462–1467, November, 1991. 相似文献
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The low-temperature reaction of magnesium with fluorobenzene has been investigated. Joint condensation of magnesium and fluorobenzene vapours at low temperatures quantitatively gave phenylmagnesium fluoride in one stage. 相似文献
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218.
A. A. Berezhnoy F. L. Vladimirov I. Yu. Grodetskii Yu. L. Korzinin V. I. Sukhanov 《Optics and Spectroscopy》2002,93(5):777-780
The possibility of usage of the spontaneous electrooptical (EO) effect in strontium barium niobate (SBN) crystals for the creation of controlled electroholographic elements is studied. It is found that unipolar EO properties of these crystals with respect to switching their spontaneous polarization make it possible to devise field-controlled holographic elements with reversible energy-independent memory for spatial position of an optical beam. 相似文献
219.
V. T. Plaksiy O. N. Suchoruchko B. P. Yefimov A. P. Kasyanenko 《International Journal of Infrared and Millimeter Waves》2002,23(4):645-650
Bismuth, antimony and its alloys are the typical representatives of a class of semimetals, which electric conductance is lower in 102-103 times, than of usual well conducting an electrical current metals. The alloys bismuth with antimony have semi-conductor properties in wide area of compositions at temperatures below 77 °K. The semimetals are rather perspective materials from the point of view of their probable application in various devices [1,2,3].In present time the semimetal alloys BiSb have wide application in thermoelectric generators and refrigerators. In work [3] the opportunity of use of semimetals BiSb with percentage content of Bi and Sb from 8 % up to 25 % was shown as high-sensitivity and of small inertion indicators of the mm range radiation where thermoelectric effect is used. The principle of action of such indicators is based on occurrence of temperature gradient in a semimetal crystal BiSb that has two contacts of the various area with flowing electrical current. Basic element of such device is the dot contact metal - semimetal. One of the main characteristics is volt-watt sensitivity of metal-semimetal BiSb contact which calculating is shown in present work. 相似文献
220.
Translated from Aktual'nye Voprosy Prikladnoi Matematiki, pp. 222–228, 1989. 相似文献