Materials Literature
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Several model structures have been generated by molecular dynamics simulations for two precursor‐derived amorphous Si‐C‐N ceramics with stoichiometry Si37C32N31 and Si40C24N36, respectively. These can be considered as possible atomistic model structures for the real amorphous ceramics. Although these models vary in th…
Li 0.5 Fe 2.5 O 4 powders were prepared by high temperature thermal decomposition (HTTD) and sol-gel methods. The sample prepared by HTTD method (SA) has space group of Fd3m. The samples annealed at 700°C (SB) and quenched at 1000°C (SC) prepared by sol-gel method have space groups of P4332 and Fd3m, respectively. The…
Silk is a natural protein fibre. It is the only natural fibre available in continuous filament form. Earlier research studies on physical structure and mechanical properties of silk have indicated that the physical and chemical architecture varies between different varieties of silk and a substantial variation of thes…
Light-emitting diodes (LEDs) have been fabricated in which optically active centers are formed by implantation of erbium ions into silicon and subsequent high-temperature annealing in an oxidizing atmosphere and the p-n junction and the ohmic contact are formed by chemical vapor deposition of polycrystalline silicon l…
A model of the accommodation mechanism of the formation of broken subboundaries has been studied by means of computer simulation. It is established that an increase in the power Ω of a disclination on a grain boundary leads to the activation of a source of dislocations in the grain volume, which results in the formati…
Solid‐state NMR spectroscopy is employed for the structural characterization of precursor‐derived Si‐B‐C‐N ceramics. Particular emphasis is given to the structural composition of the BNCx phase which plays a key role for the unusual high temperature stability of these materials. In the present work 11B{15N} REDOR and…
Structural foam cores are becoming more competitive and promise to make a greater contribution to the success of composite sandwich structures. George Marsh reports.
The crystalline and magnetic structures of YMnO 3 and LuMnO 3 hexagonal manganites under pressures of 0–6 GPa and in the temperature range 10–295 K have been investigated by neutron diffraction. Application of pressure leads to a significant decrease in the ordered magnetic moment of Mn ions (at T = 10 K) from 3.27 (0…
Potassium bis(malonato)borate C6H4BKO8 (I) was synthesized for the first time in an aqueous medium. Well-shaped single crystals were formed. Their X-ray diffraction structure (space group P $$\overline 1 $$ , a = 7.4073(2) Å, b = 7.9161(2) Å, c = 9.0755(2) Å, α 113.225(1)°, β = 91.553(1)°, γ = 104.760(2)°, Z = 2) was…
A deep analogy between the processes of low-temperature thermally induced relaxation of plastic deformation in amorphous polymers and inorganic glasses is observed. The results of the calculation of the activation energy and activation volume of this relaxation process in terms of the excited state model satisfactoril…
New complex sodium lanthanide phosphate molybdates Na2MIII(MoO4)(PO4)(MIII=Tb, Dy, Ho, Er, Tm, Lu) have been synthesized by the ceramic method (T = 600°C, τ = 48 h), and their unit cell parameters have been determined. The structures of Na2MIII(MoO4)(PO4)(MIII = Dy, Ho, Er, Lu) were refined by the Rietveld method. The…
2‐Methylene‐1,3,6‐trioxocane (MTC) and maleic anhydride (MA) were copolymerized in the presence of a radical initiator. Elemental analysis suggested that the obtained copolymer consisted of alternating monomer units. After hydrolysis of the MA carboxylate anhydride functionality, the copolymer exhibited good calcium i…
Abstract The high‐density rigid polyurethane foam (RPUF) was obtained by airtight cast molding. The morphology development during the compressive fracture process of RPUF was observed on‐line by a scanning electronic microscope (SEM). In the early stage of loading, the deformation of samples came from the tiny shape c…
Almost impurity and defect-free barium titanate (BaTiO3) nanoparticles with various sizes from 20 to 430 nm were prepared using 2-step thermal decomposition method. The nano-structures of these particles were analyzed using a synchrotron radiation X-ray diffraction (XRD). As a result, it was found that the BaTiO3nanop…
The structure of amorphous silicon oxynitride formed under nitridation conditions using ammonia gas, before the onset of silicon nitride crystallization, is determined employing high‐energy X‐ray diffraction (HEXRD) technique. The derived real‐space function suggests that smaller ring structures, especially 3R and 4R…
Abstract The complexes Ni(dmeds)(dmit), Ni(dmedt)(dmit), Ni(dpedt)(dsit), Ni(dpedt)(dmit), and Ni(dcdt)(dmit) (where dmeds is dimethylethylenediselenolate, dmedt is dimethylethylenedithiolate, dpedt is diphenylethylenedithiolate, dcdt is 1,2-bis-decylsulfanyl-ethene-1,2-dithiolate, dmit is 1,3-dithiol-2-thione-4,5-dit…
The irradiation creep-swelling interaction parameters were pecisely derived for MONJU fuel pin cladding PNC316 by irradiation tests of pressurized tubes in FFTF. It was found out that a creep-swelling coupling coefficient decreased and asymptotically approached a constant value as the swelling progresses, although it…
The graft copolymerization of acrylonitrile (AN) and ethyl acrylate (EA) comonomers onto cellulose has been carried out using ceric ammonium nitrate (CAN) as an initiator in the presence of nitric acid at 35±0.1°C. The addition of ethyl acrylate as comonomer has shown a significant effect on overall and individual gra…
Abstract Silicon membranes with through pores have been manufactured based on silicon plates with a gradient‐porous structure (GPSi), in which the pore cross section and structure varies with depth. The obtained structure can serve a basis for the development of electrodes for solid polymer fuel cells. The developed t…
Interactions in the ternary system K2MoO4-Lu2(MoO4)3-Hf(MoO4)2 have been studied by X-ray powder diffraction and differential thermal analysis. A new triple (potassium lutetium hafnium) molybdate with the 5: 1: 2 stoichiometry has been found. Single crystals of this molybdate have been grown. Its X-ray diffraction str…