Materials Literature
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Abstract The morphologies of films blown from a low‐density polyethylene (LDPE), a linear low‐density polyethylene (LLDPE), and their blend have been characterized and compared using transmission electron microscopy, small‐angle X‐ray scattering, infrared dichroism, and thermal shrinkage techniques. The blending has a…
Abstract This paper reviews selected phenomena related to the boundary friction process. The central thrust is on triboemission, defined as emission of electrons, charged particles, photons, etc., under conditions of boundary friction and/or surface damage caused by fracture processes. Low‐energy electrons are one of…
N-channel ferroelectric dynamic random access memory (FEDRAM) FETs with SrBi2Ta2O/sub 9//SiN/Si structure were fabricated and characterized. The estimated switching time (t/sub sw/) of the fabricated FET, measured at applied electric field of 376 kV/cm, was less than 50 ns, which could be significantly reduced upon sc…
Platinum nanoparticles were prepared in water-in-oil microemulsions and deposited on γ-alumina using two different methods. In the first method, the alumina support was added to the particle suspension and the microemulsion was subsequently destabilized by addition of tetrahydrofurane, whereby the particles were depos…
Stress development during the constrained sintering of a sandwich structure of alumina/glass/alumina has been studied. Stress distribution in the glass layer was calculated using a finite element method. The shear stress exhibited a maximum at the edge of the alumina/glass interface. The in‐plane tensile stress, forme…
Abstract Poly(butylene succinate‐ co ‐butylene 2‐methyl succinate) (PBSMS) random copolymers were synthesized with various comonomer compositions and their crystallization behaviour and morphology were investigated by differential scanning calorimeter, small angle X‐ray scattering and polarized optical microscopy. The…
The novel bis-naphthopyran 1 displays optical properties that are unique, differing substantively from a simple first-order superimposition of the monomeric constituents. Such a photochromophore has great promise for the development of smart optical devices.
An investigation of the growth mechanisms, electronical and structural properties, and field emissions of carbon films obtained by chemical vapour deposition showed that field emissions from films composed of spatially oriented carbon nanotubes and plate-like graphite nanocrystals exhibit non-metallic behaviour. The e…
We present magnetization studies in a series of phase-separated ${\mathrm{La}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_{3}$ manganite samples, with different low-temperature fractions of the ferromagnetic (FM) and charge-ordered antiferromagnetic phases. A particular experimental procedure probes the effect of the magn…
There are two major pathways for methionine biosynthesis in micro-organisms. Little is known about these pathways in Bacillus subtilis. The authors assigned a function to the metI (formerly yjcI) and metC (formerly yjcJ) genes of B. subtilis by complementing Escherichia coli metB and metC mutants, analysing the phenot…
We have developed a comprehensive methodology that affords regioisomerically pure trans- A 2 B -corroles bearing substituents with basic nitrogen atoms at meso positions. The corrole formation reaction involves the acid-catalyzed condensation of a dipyrromethane (DPM) and an aldehyde followed by oxidation with DDQ. Th…
PbTiO 3 thin films were prepared from alkoxide solution precursors and crystallized onto Pt/TiO2/SiO2/Si substrates. Microscopy observations revealed that the complexity of the domain walls structure decreased with the grain size. Dielectric, electrostrictive, and piezoelectric properties of the films were characteriz…
WS2 nanotubes were synthesized in large amounts by reaction of H2S with WO3 nanopowder using a fluidized-bed reactor. The nanotubes come often in a few centimeter long bundles or alternatively as a few centimeters large foil deposited on the quartz wall of the reactor. Transmission electron microscopy revealed that th…
The lifetime of tetragonal zirconia ceramic implants is controlled by their resistance to slow crack growth and low‐temperature degradation (LTD). A decrease of the grain size is often proposed to decrease the effect of LTD on zirconia; however, this decrease also reduces the resistance to crack propagation. An altern…
120 keV carbon ions implantations at high fluences (0.5–8×1017 ions cm−2) were performed at elevated temperature (⩾500 °C) in silver layers deposited on various substrates (Si (100), 304 L stainless steel, and pure fused silica). Spherical carbon onions (3–15 nm in diameter) were so produced in the silver layers. A pu…
The paragenesis and compositional variation of strontium-apatite from three new localities are characterized. At Lovozero, in the Kola Peninsula, Russia, strontium-apatite forms elongate crystals and thin reaction-induced rims on early strontian fluorap atite in nepheline syenite pegmatites. The apatite-group minerals…
The present study is focused on the vibrational and structural characterization of a set of disordered hydrogenated carbon nitride (a-CN:H) thin films grown by reactive sputtering. A comparative analysis of the experimental results as achieved by Raman and infrared (IR) spectroscopies is made. The disorder-induced fea…
We are presenting a three-dimensional model of MalK, the ABC subunit of the maltose transporter from Escherichia coli and Salmonella typhimurium. It is based on the recently published crystal structure of the closely related Thermococcus litoralis MalK. The model was used to identify the position of mutations affectin…
A temperature dependence of the optical energy gap E g (T) for the CdSxSe1−x quantum dots synthesized in a borosilicate glass matrix was investigated in the range of 4.2–500 K. It was demonstrated that this dependence reproduced the dependence E g (T) for bulk crystals and is described by the Varshni formula for $$\ba…
A new kind of demagnetizing factors is suggested, that express the local field in a ferromagnetic sample. An analytic expression is given for the case of a general rectangular prism and is compared with a generalization of the ballistic demagnetizing factor. These two factors are found to be nearly the same in the par…