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941.
The possibility is demonstrated of using an addition of periclase-chromite filler (PCF) prepared from PCF grade broken material
articles in medium-cement concrete with chamotte filler. The effect of this addition on cement hardening duration, strength
and heat resistance is considered.
Translated from Novye Ogneupory, No. 8, pp. 42–46, August 2008. 相似文献
942.
Programs are presented for calculating dusty air flow in ventilation systems, which have been derived from the method of singular
integral equations. They allow one to construct flow lines and determine the velocity pattern for the air in a closed rectangular
region with outlet, flow, and extraction holes; a study is made on the dust particle behavior in the aerodynamic field in
which there may be a rotating cylinder or pumping cylinder; determinations are made of the concentration and grain-size composition
of the dust in the extraction hole; one can construct flow lines and single-particle paths in multicoupled regions of potential
flows containing any number of rotating cylinders and cylinder pumps.
Translated from Novye Ogneupory, No. 5, pp. 53–58, May, 2008. 相似文献
943.
944.
A very important characteristic of coking coal is its clinkering ability, i.e., its ability to form a nonvolatile solid residue, consisting of disparate grains, on heating in specific conditions. The clinkering ability of the coal is determined by the properties of its plastic mass. Various methods may be used to evaluate the plastic-ductile properties of the coal. However, since the 1930s, the main method used to evaluate the clinkering properties of coal, within the nations of the former Soviet Union, has been the Sapozhnikov-Bazilevich plastometric method, because it provides more information than competing approaches. For the same reason, the thickness of the plastic layer, which is one of the parameters determined by this method, is used for coal classification in State Standard GOST 25543-88 (Lignite, Coal, and Anthracite: Genetic and TEchnological Classification) and its Ukrainian counterpart DSTU 3472-96 (Lignite, Coal, and Anthracite: Classification). This explains the strict requirements on the accuracy and reliability of the plastometric characteristics. 相似文献
945.
A technique is proposed for introducing microdoses (10?5–10?10 g) of germanium and indium metals into semiconductor compounds by coulometric titration in a solid electrolyte cell. The solid electrolytes that are reversible with respect to germanium cations (the GeSe-GeI2 system containing 5 mol % GeI2) and indium cations (the InCl3-MgCl2 system containing 15 mol % MgCl2, the InCl3-CdCl2 system containing 1.5 mol % CdCl2, and the In2S3-InCl3 system containing 5 mol % InCl3) are chosen, and their electric transport properties are characterized. The optimum conditions for electrochemical doping (temperature, current density), under which the current efficiency reaches 90–100%, are determined. The doping with germanium and indium is performed for nonstoichiometric compounds, such as lead monotelluride, indium sulfide, and ternary chalcogenide spinel Cd1 ± δCr2Se4. The doping efficiency is controlled by measuring the electromotive force of the corresponding electrochemical cells and the Hall effect, as well as using the electrical conductivity method. The solid electrolytes that are reversible with respect to indium are used to determine the standard Gibbs energies of formation of a number of indium-containing semiconductors. 相似文献
946.
Hung-da Wan F. Frank Chen 《The International Journal of Advanced Manufacturing Technology》2008,38(9-10):995-1005
A Kanban system facilitates lean principles in a simple and effective way. While reportedly successful in many manufacturing firms, the conventional Kanban systems using physical cards suffer from human errors, limited tracking capability, and so on. To make the information flow leaner, software providers add new features to their existing programs for manufacturing systems to computerize Kanban activities. As Web-based technologies advance rapidly, developing an entirely Web-based Kanban system appears to be feasible and promising. This paper presents the advantages, limitations, and challenges of Web-based Kanban systems. An experimental program has been developed based on PHP+MySQL, a popular Web programming platform. The server-executed program features cross-platform compatibility, real-time tracking and performance monitoring, and greatly enhanced information contents compared to physical Kanbans. Human errors are minimized by the automated transactions; nevertheless, the interfacing and data maintenance require further research efforts. 相似文献
947.
948.
Vjacheslav V. Zuev 《Journal of Polymer Research》2008,15(5):351-356
Functionalized polyanilines containing biphenyl, terphenyl, carbazole, anthracene, and 4-n-hexylphenyl moieties were synthesized though the reaction of polyaniline in emeraldine base form with sodium salt of corresponding
vinylketoaromatics with quantitative yields. Polymers were characterized with Fourier transform infrared spectroscopy, proton
nuclear magnetic resonance spectroscopy, and thermogravimetry. The emission characteristics of these polymers in N-methyl-2-pyrrolidone solution were examined. The functionalized polyanilines exhibited an intense green emission. 相似文献
949.
Various nitroaromatics are successfully reduced to amines with 100% conversion and selectivity in methanol at low temperature (≈5 °C), by using versatile system of 5% Ni–SiO2 catalyst and NaBH4 and in situ generation of Ni boride. The catalytic efficiency of Ni loading (5%, 10% and 15%) with silica or titania as support materials is investigated for reduction of nitrobenzene. The Ni–titania/NaBH4 system recorded lower conversion and selectivity. The IR studies indicate that silica support does not have free –OH group on its surface. Thus the nickel boride is anchored to the silica to facilitate the catalytic process. 相似文献
950.