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111.
Bican Osman Bayça Salih Uğur Kuleyin Hamdi Gümrük Recep 《Metal Science and Heat Treatment》2021,63(3-4):156-162
Metal Science and Heat Treatment - The effect of solid boronizing at 950°C for 2 and 4 h on the phase composition, microstructure, hardness and abrasive wear of steel AISI 304L is studied... 相似文献
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A. A. Babenko V. I. Zhuchkov L. A. Smirnov A. V. Sychev A. A. Akberdin A. S. Kim M. F. Vitushchenko A. A. Dobromilov 《Steel in Translation》2015,45(11):883-886
A technology for slag formation in the ladle–furnace unit is considered; the slag is based on the CaO–SiO2–MgO–Al2O3–B2O3 system. This technology permits both microalloying of the steel with boron (reduced from the oxide phase) and desulfurization of the steel. The resulting boron content in the steel is 0.001–0.008%; the sulfur content in low-alloy steel and pipe steel is low (0.004–0.010%); and the consumption of manganese ferroalloys is reduced to 0.5 kg/t for 08кп steel and 1.4 kg/t for 09Г2C steel. In addition, the proposed technology increases the strength of the rolled steel, without loss in its plasticity; and reduces the environmental impact thanks to the replacement of fluorspar by colemanite. 相似文献
114.
Martin Michálek Monika Michálková Gurdial Blugan Jakob Kuebler 《Ceramics International》2018,44(3):3255-3260
Up to now, commercially available alumina ceramics were claimed to have strength between 400 and 550 MPa. However, our study shows strength ~ 2 times higher for commercially available alumina than commonly believed. The average and characteristic strength, measured on 31 pure alumina ceramic discs by ball on three balls (B3B) test, were 1205 ± 93 MPa and 1257 MPa, respectively, with a Weibull modulus of m = 11.8. Tested specimens were in form of discs with a diameter of 5 mm and thickness 0.5 mm. The grain size distribution of the alumina is bimodal with an average grain size of ~ 850 nm measured at the surface. The fracture reveals a mixed transgranular / intergranular failure mode. To avoid incorporation of additional flaws, the discs were tested as sintered. The characteristic flexural strength measured in B3B was recalculated according to Weibull theory for standard 4-point bending bars of size 3 × 4 × 45 mm as bend 856 MPa. The measured strength of nearly 900 MPa shows the potential of strength for high purity alumina ceramics. 相似文献
115.
V.I. Popkov O.V. Almjasheva V.N. Nevedomskiy V.V. Panchuk V.G. Semenov V.V. Gusarov 《Ceramics International》2018,44(17):20906-20912
Formation and structural transformations of yttrium orthoferrite crystals have been studied using X-ray diffractometry, Mössbauer spectroscopy and transmission electron microscopy combined with electron microdiffraction. Said processes have been studied under heat treatment of glycine-nitrate combustion products. There have been identified formations of three structural yttrium orthoferrite modifications – amorphized hexagonal <h1>-YFeO3 (P63cm) and nanocrystalline hexagonal h2-YFeO3 (P63/mmc), as well as nanocrystalline orthorhombic o-YFeO3 (Pbnm), which are selectively formed depending on available three-dimensional confinements. Based on the analysis of changes in the fluid and size composition formulation, it has been proposed mechanism for formation and transformation of YFeO3 nanocrystals, including growth stage of h2-YFeO3 crystals due to amorphized phase of <h1>-YFeO3 up to critical size of about 15?nm and their subsequent transformation into orthorhombic form o-YFeO3. 相似文献
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Covalent triazine frameworks (CTFs) have been recently employed for visible light-driven photocatalysis due to their unique optical and electronic properties. However, the usually highly hydrophobic nature of CTFs, which originates from their overall aromatic backbone, leads to limitations of CTFs for applications in aqueous media. In this study, we aim to extend the range of the application media of CTFs and design hybrid material of a CTF and mesoporous silica (SBA-15) for efficient photocatalysis in aqueous medium. A thiophene-containing CTF was directly synthesized in mesopores of SBA-15. Due to the high surface area and the added hydrophilic properties by silica, the hybrid material demonstrated excellent adsorption of organic molecules in water. This leads not only to high photocatalytic performance of the hybrid material for the degradation of organic dyes in water, but also for efficient photocatalysis in solvent-free and solid state. Furthermore, the reusability, stability and easy recovery of the hybrid material offers promising metal-free heterogeneous photocatalyst for broader applications in different reaction media. 相似文献
118.
László Lőrincz Máté Zsemberi György Bánsághi Tamás Sohajda Edit Székely 《化学工程与技术》2018,41(7):1466-1472
Chiral molecules, especially enantiomers and diastereomers of purity > 99 %, present a significant market share within the chemical, pharmaceutical, and flavor industries. Antisolvent precipitations, both batch and semicontinuous operations to serve the current trends in flow chemistry were demonstrated to be environmentally benign and efficient tools in achieving high optical purities. Although salts are known to be insoluble in supercritical CO2, instabilities of the nascent salts were detected and applied for increasing efficiency. Diastereomeric excess values of the crystalline products exceeded 99 % in maximum of three consecutive steps both by repeated resolution with half molar equivalent of the amine to the acid and by direct recrystallization of the salts. 相似文献
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120.
Gina Cavaliere Giovanna Trinchese Nadia Musco Federico Infascelli Chiara De Filippo Vincenzo Mastellone Valeria Maria Morittu Pietro Lombardi Raffaella Tudisco Micaela Grossi Vincenzo Monda Monica I. Cutrignelli Antonietta Messina Serena Calabrò Heleena B. Moni Luigi Stradella Giovanni Messina Marcellino Monda Maria Pina Mollica 《Journal of dairy science》2018,101(3):1843-1851
Excessive energy intake may evoke complex biochemical processes characterized by inflammation, oxidative stress, and impairment of mitochondrial function that represent the main factors underlying noncommunicable diseases. Because cow milk is widely used for human nutrition and in food industry processing, the nutritional quality of milk is of special interest with respect to human health. In our study, we analyzed milk produced by dairy cows fed a diet characterized by a high forage:concentrate ratio (high forage milk, HFM). In view of the low n-6:n-3 ratio and high content of conjugated linoleic acid of HFM, we studied the effects of this milk on lipid metabolism, inflammation, mitochondrial function, and oxidative stress in a rat model. To this end, we supplemented for 4 wk the diet of male Wistar rats with HFM and with an isocaloric amount (82 kJ, 22 mL/d) of milk obtained from cows fed a diet with low forage:concentrate ratio, and analyzed the metabolic parameters of the animals. Our results indicate that HFM may positively affect lipid metabolism, leptin:adiponectin ratio, inflammation, mitochondrial function, and oxidative stress, providing the first evidence of the beneficial effects of HFM on rat metabolism. 相似文献