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61.
Daniil I. Kolokolov Alexander G. Stepanov Ivan S. Glaznev Yurii I. Aristov Marie Plazanet Herv Jobic 《Microporous and mesoporous materials》2009,125(1-2):46
Quasi-elastic and inelastic neutron scattering techniques have been used to study the dynamics of water in CaCl2 · nH2O (n = 1/3,2,4,6,9) hydrates dispersed in silica, in comparison with the bulk hydrates. Inelastic scattering shows that the water molecules in dispersed hydrates are in an amorphous state. Quasi-elastic scattering indicates a higher mobility of water in the hydrates dispersed in silica, compared to bulk hydrates. The self-diffusivity of water in the dispersed hydrates increases with water concentration, while remaining below the one of pure water. The neutron and pulsed-field gradient NMR diffusivities are similar, which indicates that the hydrates form a thin and continuous layer on the pore walls of silica. 相似文献
62.
Podchernyaeva Irina A. Kostenko Alexei D. Guslienko Yurii A. Uvarova Irina V. 《Powder Metallurgy and Metal Ceramics》2004,43(1-2):35-38
The effect of layer-by-layer electric-spark alloying on the tribological parameters of a composite electrolytic coating of the system Ni – B is studied. It is shown that layer-by-layer electric-spark alloying with intermetallic TiAl and a composite AlN – ZrB2 halves coating wear and prevents transfer of coating material to the counterbody. The reason for this is formation of a graded structure for the surface layer including zircon ZrSiO4 and intermetallic TiAl. The latter is responsible for formation of β-tialite during tribological oxidation acting as a solid lubricant. 相似文献
63.
The feasibility of replacing solid chrome plating with a composite electrolytic coating based on Ni and Fe is discussed. The physical and mechanical properties of such a coating are shown to be on a par with or superior to those of solid chrome plating. The proposed coating costs less than does chrome plating. 相似文献
64.
Technology for the production of new materials based on the heat-resistant powder metallurgy nickel alloy ÉP975 was developed, and the mechanical and tribological properties of these investigated. The formation features of the metallographic structure of the materials was studied. Recommendations for the practical use of the new composites are given. 相似文献
65.
Small but strong: A review of the mechanical properties of carbon nanotube-polymer composites 总被引:7,自引:0,他引:7
The superlative mechanical properties of carbon nanotubes make them the filler material of choice for composite reinforcement. In this paper we review the progress to date in the field of mechanical reinforcement of polymers using nanotubes. Initially, the basics of fibre reinforced composites are introduced and the prerequisites for successful reinforcement discussed. The effectiveness of different processing methods is compared and the state of the art demonstrated. In addition we discuss the levels of reinforcement that have actually been achieved. While the focus will be on enhancement of Young’s modulus we will also discuss enhancement of strength and toughness. Finally we compare and tabulate these results. This leads to a discussion of the most promising processing methods for mechanical reinforcement and the outlook for the future. 相似文献
66.
The effect of particle size for the original silicon carbide and carbon powders and effects connected with influence of the original components structures, as well as the structure and phase composition of self-bonded silicon carbide are studied. 相似文献
67.
68.
Thomas Connolly Richard C. Smith Yenny Hernandez Yurii Gun'ko Jonathan N. Coleman J. David Carey 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(7):826-831
The electron field‐emission (FE) characteristics of functionalized single‐walled carbon‐nanotube (CNT)–polymer composites produced by solution processing are reported. It is shown that excellent electron emission can be obtained by using as little as 0.7% volume fraction of nanotubes in the composite. Furthermore by tailoring the nanotube concentration and type of polymer, improvements in the charge transfer through the composite can be obtained. The synthesis of well‐dispersed randomly oriented nanotube–polymer composites by solution processing allows the development of CNT‐based large area cathodes produced using a scalable technology. The relative insensitivity of the cathode's FE characteristics to the electrical conductivity of the composite is also discussed. 相似文献
69.
Yurii Ivanov Victor Gromov Vasilii Kormyshev Krestina Aksenova Anton Teresov 《Materials Science & Technology》2017,33(17):2040-2045
The microstructure and microhardness distribution in the surface of low-carbon Hardox 450 steel coated with alloyed powder wires of different chemical compositions are studied. It is shown that the microhardness of 6–8?mm-thick surfaced layer exceeds that of base metal by more than two times. The increased mechanical properties of surfaced layer are caused by the submicro and nanoscale dispersed martensite, containing the niobium carbides Nb2C, NbC and iron borides Fe2B. In the bulk plates, a dislocation substructure of the net-like type with scalar dislocation density of 1011?cm?2 is observed. The layer surfaced with the wire containing B possesses highest hardness. The possible mechanisms and temperature regimes of niobium and boron carbides in surfacing are discussed. 相似文献
70.
Maria G. Semenova Anna S. Antipova Larisa E. Belyakova Yurii N. Polikarpov Lyubov A. Wasserman Tamara A. Misharina Margarita B. Terenina Rimma V. Golovnya 《Food Hydrocolloids》2002,16(6):R72
This paper considers the prominent features in competitive binding of aroma esters from their mixtures to 11S globulin of broad beans (legumin) in aqueous medium at pH 7.2 and ionic strength of 0.05 mol dm−3. Series of alkyl acetates (C4–C8) and methyl esters of carbonic acids (C5–C9), differing in the length of hydrocarbon chain, have been under our studying. To accomplish the ends of the study, a combination of ultrafiltration and gas–liquid chromatography (GC) has been used. An increase in the length of hydrocarbon chain of the aroma esters brought about greater binding affinity for the protein, the occurrence of some structural restrictions in the interior of the protein molecule, preventing binding, and the change in the binding mechanism of the aroma compounds at the specific critical length of hydrocarbon chain. Differential scanning microcalorimetry data suggested that the revealed changes in the binding mechanism of the studied aroma compounds were attributable to the conformational modification of the protein globule as a result of binding with the aroma compounds. A distinguishing feature in binding of methyl esters of carbonic acids with legumin was their greater binding affinity for the protein as compared with alkyl acetates. The mutual effect of aroma compounds on binding from their equimolar mixtures to the protein made itself evident, firstly, as a drastic increase in the binding extent of aroma esters, having rather long hydrocarbon chain and, secondly, as a dramatic change in the binding mechanism of the aroma esters with relatively short hydrocarbon chain. 相似文献