Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
We have carried out ab initio molecular orbital calculations on four isomers of ${\mathrm{Si}}_{9}{\mathrm{O}}_{25}{\mathrm{H}}_{14}$ modeling the local structure of ${\mathrm{SiO}}_{2}$ glass at the Hartree-Fock level. These clusters consist of two-, three-, four-, five-, and/or six-membered silica rings. The strain…
The mechanism of the acoustoplastic effect is discussed which arises when an oscillatory stress of an acoustic frequency is superimposed during quasi-static deformation of a crystal. The kinetics of the acoustoplastic effect and its dependence on the amount of plastic deformation, amplitude of acoustic-frequency stres…
We present results in the final part of a three-part study employing standard test data (STD) to estimate errors in peak parameters derived from data analysis procedures used in x-ray photoelectron spectroscopy (XPS). The XPS-STD are simulated doublet and singlet XPS spectra based on spline polynomial models of measur…
Vinylbenzyl chloride (VBC) has been used as a coupling agent in Convergent Living Anionic Polymerization to produce polymers with dendritic branching. The slow addition of a stoichiometric amount of VBC to living polystyrene chains allows the coupling to proceed through macromonomer formation followed by vinyl additio…
Catalytic synthesis and transmission electron microscopy (TEM) of multi-wall carbon nanotubes are presented. Silica, zeolite and alumina supported cobalt catalysts were prepared by different methods (impregnation and ion-adsorption precipitation) and were used to produce nanotubes. The synthesis was carried out in a f…
Polycrystalline solid solutions of phosphate and vanadate calcium apatites were synthesized and studied by XRD, XPS, 31P and 51V NMR, FTIR and UV spectroscopies. Homogeneous distributions of vanadium within the solid and the surface were obtained. While 51V NMR spectra suggest an axial symmetry of the vanadate group,…
Two multicomponent Zn-tetraphenylporphyrin (ZnTPP) based building blocks have been synthesized for designing microporous crystalline solids. Reactions of ZnTPP with 4,4′-bipyridine (4,4′-bpy) in two different molar ratios gave two coordination complexes namely [(ZnTPP)3{μ-4,4′-bpy}2] I and [(ZnTPP)2{μ-4,4′-bpy}] II. C…
A series of Mn porphyrins bearing one to eight β-nitro substituents were synthesized in high yield in three steps by using a new general method for selective nitration of a Zn(meso-tetraarylporphyrin); this Mn porphyrin series exhibits a remarkably wide span of Mn(III)/Mn(II) redox potentials from −290 to + 1150 mV (v…
Nylon 11 coatings filled with nanosized silica and carbon black have been produced using the high velocity oxy-fuel (HVOF) combustion spray process. The physical properties and microstructure of coatings produced from nylon 11 powders with starting particle sizes of 30 and 60 μm have been evaluated as a function of th…
Structural modifications of a commercial polypropylene (PP) sample are studied by IR spectroscopy. Aging this sample under an ambient atmosphere with or without the presence of ambient light shows the oxidation process to be the most predominant. Spectral analysis reveals that the commercial sample is isotactic and al…
Novel silica materials bearing single or multiple (lotus-shaped) hollow fiber structures with 5–10 nm inner diameters and a spherical structure were created using sugar-integrated organogelators (1–4) as templates by sol–gel polymerization of TEOS.
We prepared two kinds of sulfated silk fibroins, SclFib30 and SclFib31, which contain different amounts of sulfate. These sulfated silk fibroins have anti-HIV-1 activity in vitro, apparently due to interference with the adsorption of virus particles to CD4+ cells, and completely blocked virus binding to the cells at a…
Abstract The manufacturing of composites of ultra high molecular weight polyethylene and ceramics with conductive properties has been investigated. Attention has been focused on the lowering of the amount of filler necessary to achieve low resistivity. Using segregated networks, mixing large polymer particles and subm…
Recent developments in the chemistry of polyimides (PIs) for liquid crystal (LC) alignment films are reviewed. Some important properties, such as low temperature curing, generation of pretilt angles, and electrical properties, are summarized with respect to the chemical structures of the PI materials. In addition, the…
This paper reviews and presents work carried out in the French Atomic Energy Commission (CEA) on the subject of nuclear severe accidents, i.e. those which are accompanied by melting of the nuclear core material. The emphasis is on the (crucial) thermodynamic and material behaviour of corium melts in the solidus-liquid…
The objective of this article is to describe the present understanding of the growth, processing, and properties of diamond for electronic applications.
This paper deals with the irradiation-induced changes in the microstructure of FRAMATOME advanced Zr-base alloys and the correlations with their irradiation creep and growth behavior. The first part is dedicated to experimental irradiations performed at 280 and 350°C in a CEA metallurgical test reactor (Siloé, 1 to 10…
Various types of signal-responsive polymers were grafted on surfaces of porous membranes as polymer brushes. The grafted polymers shrank and extended in response to environmental signals, such as pH, ionic strength, temperature, redox reaction and photo-irradiation. The pore size was regulated by the extent of the pol…
The vitreous SiO 2 samples irradiated with fast neutrons at a dose of 5×10 17 −2.2×10 20 per cm 2 are investigated by the Raman scattering technique. It is demonstrated that the maximum of the low-frequency Raman spectrum (boson peak) shifts with an increase in the irradiation dose, and the medium-range order size dec…
Spherical precursors to phosphors are reported that lead to fired materials of 1–5 μm in size with the majority of particles below 4 μm. The photoluminescence performance of the phosphors prepared by this method is as good as those of commercial phosphors, where the average size particle has a volume nine times greate…