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61.
62.
O. Yu. Golubeva E. Yu. Brazovskaya N. Yu. Ul’yanova Yu. A. Morozova 《Glass Physics and Chemistry》2018,44(2):108-114
Nanocomposites based on zeolite Beta and magnetite nanoparticles (MNs) are obtained under hydrothermal conditions. Nanoparticles synthesized under various conditions and having different surface properties are added at the preparatory stage of a zeolite Beta gel that is then subjected to hydrothermal treatment at 140°C for 48 h. It is found that modifying the surface of the nanoparticles by a cationic polymer, polydiallyldimethylammonium chloride (PDDAC) makes it possible to significantly increase the amount of magnetite introduced into the zeolite structure (up to 40 wt % compared to 2–10 wt % for unmodified particles) and obtain zeolites with a magnetic core that contain nanoparticles within the zeolite structure. It is shown that doping the initial gels with MNs allows obtaining magnetically sensitive zeolites with particles of 100 to 200 nm, which are 200 nm smaller than the zeolite particles obtained under the same conditions without doping. 相似文献
63.
A. I. Ul’yanov N. B. Arsent’eva A. V. Zagainov A. L. Ul’yanov E. P. Elsukov G. A. Dorofeev 《Russian Journal of Nondestructive Testing》2004,40(7):462-468
The influence of cold plastic deformation on phase transformations and on the magnetic properties of powder specimens of the Fe-5-at. % C alloy modeling U12 high-carbon steel has been investigated in the context of nondestructive testing. It has been shown that under high plastic deformation dissolution of cementite Fe3C occurs by the scheme -Fe + Fe3C -Fe + (Fe3C)d + -Fe + Am(Fe-C). An increase in the rate of plastic deformation of powders decreases the coercive force from 50 to 13 A/cm due to the low coercivity of the #x03B1;-Fe and Am(Fe-C) phases. The structural state of high-carbon steels following a strong cold plastic deformation can be determined by measuring two magnetic parameters: the coercive force, and the temperature dependence of differential magnetic permeability.Translated from Defektoskopiya, Vol. 40, No. 7, 2004, pp. 42–52.Original Russian Text Copyright © 2004 by A.I. Ulyanov, Arsenteva, Zagainov, A.L. Ulyanov, Elsukov, Dorofeev. 相似文献
64.
I.?A.?BalaganskiiEmail author L.?A.?Merzhievskii V.?Yu.?Ul’yanitskii I.?A.?Bataev A.?A.?Bataev A.?D.?Matrosov I.?A.?Stadnichenko I.?S.?Batraev A.?V.?Vinogradov 《Combustion, Explosion, and Shock Waves》2018,54(1):119-124
The compression of ceramic (corundum) tubes by the detonation products of explosives have been studied experimentally and numerically. The formation of the shaped-charge jet of ceramic particles and its effect on steel witnesses targets has been investigated. The tubes were produced by detonation spraying. Ceramic particles were deposited on copper tubes, which were then dissolved in a solution of ferric chloride. In the experiments, a considerable penetration of the flow of ceramic particles was observed. During the interaction of the flow with the target, the target material was partially evaporated, as shown by metallographic analysis. Numerical analysis of the formation of the discrete shaped-charge jet showed that the maximum velocity of the jet head was about 23 km/s, and the velocity of the main part of the jet was about 14 km/s. 相似文献
65.
Melt compounded nanocomposites with semi‐interpenetrated network structure based on natural rubber,polyethylene, and carrot nanofibers 下载免费PDF全文
The present study deals with the processing and characterization of cellulose nanocomposites natural rubber (NR), low‐density polyethylene (LDPE) reinforced with carrot nanofibers (CNF) with the semi‐interpenetrated network (S‐IPN) structure. The nanocomposites were compounded using a co‐rotating twin‐screw extruder where a master‐batch of NR and CNF was fed to the LDPE melt, and the NR phase was crosslinked with dicumyl peroxide. The prepared S‐IPN nanocomposites exhibited a significant improvement in tensile modulus and yield strength with 5 wt % CNF content. These improvements are due to a better phase dispersion in the S‐IPN nanocomposites compared with the normal blend materials, as demonstrated by optical microscopy, electron microscopy and ultraviolet–visible spectroscopy. The S‐IPN nanocomposite also displayed an improved crystallinity and higher thermal resistance compared with NR, CNF, and the normal blend materials. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45961. 相似文献
66.
Muhammad Wajid Ullah Mazhar Ul Islam Shaukat Khan Nasrullah Shah Joong Kon Park 《Korean Journal of Chemical Engineering》2017,34(6):1591-1599
Conventional approaches of regulating natural biochemical and biological processes are greatly hampered by the complexity of natural systems. Therefore, current biotechnological research is focused on improving biological systems and processes using advanced technologies such as genetic and metabolic engineering. These technologies, which employ principles of synthetic and systems biology, are greatly motivated by the diversity of living organisms to improve biological processes and allow the manipulation and reprogramming of target bioreactions and cellular systems. This review describes recent developments in cell biology, as well as genetic and metabolic engineering, and their role in enhancing biological processes. In particular, we illustrate recent advancements in genetic and metabolic engineering with respect to the production of bacterial cellulose (BC) using the model systems Gluconacetobacter xylinum and Gluconacetobacter hansenii. Besides, the cell-free enzyme system, representing the latest engineering strategies, has been comprehensively described. The content covered in the current review will lead readers to get an insight into developing novel metabolic pathways and engineering novel strains for enhanced production of BC and other bioproducts formation. 相似文献
67.
M. Kamruzzaman Chaoping Liu A. K. M. Farid Ul Islam J. A. Zapien 《Semiconductors》2017,51(12):1615-1624
The thin film of Sb2Se3 was deposited by thermal evaporation method and the film was annealed in N2 flow in a three zone furnace at a temperature of 290°С for 30 min. The structural properties were characterized by scanning electron microscopy (SEM), transmission electron microscopy (ТЕМ), X-ray diffraction (XRD) and Raman spectroscopy, respectively. It is seen that the as-deposited film is amorphous and the annealed film is polycrystalline in nature. The surface of Sb2Se3 film is oxidized with a thickness of 1.15 nm investigated by X-ray photolecetron spectroscopy (XPS) measurement. Spectroscopic ellipsometry (SE) and UV–vis spectroscopy measurements were carried out to study the optical properties of Sb2Se3 film. In addition, the first principles calculations were applied to study the electronic and optical properties of Sb2Se3. From the theoretical calculation it is seen that Sb2Se3 is intrinsically an indirect band gap semiconductor. Importantly, the experimental band gap is in good agreement with the theoretical band gap. Furthermore, the experimental values of n, k, ε1, and ε2 are much closer to the theoretical results. However, the obtained large dielectric constants and refractive index values suggest that exciton binding energy in Sb2Se3 should be relatively small and an antireflective coating is recommended to enhance the light absorption of Sb2Se3 for thin film solar cells application. 相似文献
68.
I.?B.?Ban’kovskayaEmail author I.?G.?Polyakova D.?V.?Kolovertnov T.?M.?Ul’yanova 《Glass Physics and Chemistry》2017,43(2):170-173
Coatings on graphite that are stable to oxidation and based on the silicon–boron–zirconium boride composite containing from 5 to 50% of fibrous zirconium dioxide as a modifying dopant have been produced by the suspension–annealing method. A nonporous layer is formed at the zirconium dioxide content ranging from 5 to 15%, while a porous layer is formed at its 50% content. A glass-forming melt, as well as zirconium dioxide and silicate, is formed during thermal treatment as a result of the chemical reactions with the oxygen in air. The zirconium silicate content increases, along with the modifier’s concentration and temperature. 相似文献
69.
Critical evaluation of measures to mitigate phosphorus losses from agricultural land to surface waters in Sweden 总被引:1,自引:0,他引:1
The aim of this paper is to collate information on potential measures to reduce phosphorus (P) losses, with particular reference to Sweden. In Sweden, three dominant types of soils or soil profiles are at risk of suffering from high P losses through different pathways: clay soils with a naturally poor structure, usually situated on the large central plains, are prone to lose P through drain tiles; silty soils, usually situated on hilly terrain, are prone to erosion; and sandy soils with a low P sorption capacity in both topsoil and subsoil and that have had heavy applications of fertilisers, are prone to high leaching losses. Fields with such soils and landscape position with connectivity to surface waters may lose more than 0.5 kg P ha year-1 and often more than 1 kg P ha year-1. Losses of soluble reactive P (SRP) are commonly 30-50% of the total P losses. Improved soil tillage together with other measures aimed at improving soil structure are suggested to have the best potential to reduce losses, with short-term and long-term effects, for the clayey and silty soil profiles. For the silty soils, keeping the surface densely vegetated in winter and liming backfill of the drainage systems are suggested to be important ways to reduce the losses of particulate P (PartP). For sandy soils prone to P leaching, appropriate application of fertiliser and improved contact between fertiliser and the soil may be one of the few effective ways to reduce SRP losses. 相似文献
70.
Khurshid Salman Arif Saqib Iqbal Hafiza Mehwish Akbar Qurrat Ul Ain Yousaf Shahid 《Food science and biotechnology》2020,29(2):243-249
Food Science and Biotechnology - Current study was designed to evaluate sensory and textural quality characteristics of chapatti, a commonly consumed flat bread in South-Asia in relation to flour... 相似文献