Materials Literature
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Transparent conducting indium tin oxide (ITO) thin films were grown by pulsed laser deposition (PLD) on glass substrates. The structural, electrical and optical properties of these films were investigated as a function of film thickness. Films were deposited using a KrF excimer laser at a fluence of 2 J/cm<SUP>2</SUP>…
Carbon nanotubes are of major interest because they combine nanoscale dimensions, structural regularity, exceptional mechanical properties, and interesting electrical properties. We have been primarily concerned with the use of nanotube assemblies as novel electromechanical actuators. The use of nanotube sheets as ele…
An ionic polymer-metal composite (IPMC) consisting of a thin Nafion sheet, platinum plated on both faces, undergoes large bending motion when an electric field is applied across its thickness. Conversely, a voltage is produced across its faces when it is suddenly bent. A micromechanical model is developed which accoun…
An extensive investigation of optical properties was carried out for Tm 3+ -doped Ca 4 GdO(BO 3 ) 3 crystals in the 5-300 K temperature range. Based on absorption and emission spectra at 5 K, crystal field levels of active ions have been located. Non-equivalent sites for Tm 3+ in the Ca 4 GdO(BO 3 ) 3 matrix have been…
We report the first application of dynamic interfacial tension measurements to characterize segregation rates of diblock copolymers to a polymer−polymer interface. The system investigated is a poly(styrene- b -dimethylsiloxane) [P(S- b -DMS); M n = 13 000] symmetric diblock copolymer added to a molten blend of the cor…
Using x-ray scattering we have measured the response of the incommensurate charge-density wave (CDW) modulation in the quasi-low-dimensional material 2 H -NbSe 2 to applied magnetic fields at low temperatures. The application of a magnetic field, either perpendicular or parallel to the layers of a single crystal of 2…
Electron magnetic resonance (EMR) studies of paramagnetic species with the spin S ⩾ 1 at orthorhombic symmetry sites require an axial zero-field splitting (ZFS) parameter and a rhombic one of the second order ( k = 2), whereas at triclinic sites all five ZFS ( k = 2) parameters are expressed in the crystallographic ax…
The vortex lattice melting transition in single crystals Bi2Sr2CaCu2O8+d was studied by the in-plane resistivity measurements in magnetic fields tilted away from the c-axis to the ab-plane. In order to avoid the surface barrier effect which hinders the melting transition in the conventional transport measurements, we…
It is shown that, contrary to widely held beliefs, the potentials of spin-density-functional theory (SDFT) are not unique functionals of the spin densities. Explicit examples of distinct sets of potentials with the same ground-state densities are constructed, and general arguments that uniqueness should not occur in S…
We have performed detailed first-principles calculations to determine the eigenvectors of the zone-centre modes of hexagonal BaTiO 3 and shown that the experimentally relevant soft modes can be represented as suitable combinations of basic local distortions taken directly from the better known perovskite phase. The he…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Thermoplastic polyurethane elastomers (TPUs) are generally synthesized by using the two-step, so-called prepolymer, method. To study the influence of the prepolymer on the properties of the final TPUs, four polyurethane prepolymers were prepared from a diisocyanate and a macroglycol by using different NCO/OH ratios. T…
Three-dimensional structures of functionally uncharacterized proteins may furnish insight into their functions. The potential benefits of three-dimensional structural information regarding such proteins are particularly obvious when the corresponding genes are conserved during evolution, implying an important function…
Thermoplastic polyurethane elastomers (TPUs) of constant composition were prepared by using the prepolymer method and by changing the reaction conditions (prepolymerization and chain-extension time) to study the influence of these conditions on the final TPU properties. The TPUs were characterized by gel permeation ch…
The synthesis of thermoplastic polyurethane elastomers (TPUs) is generally carried out using the prepolymer method. To study the influence that the properties of the prepolymer may have in the final TPUs, four TPUs were prepared by using different NCO/OH ratios. The prepolymers and the macroglycol used in their synthe…
The kinetics of ethylene epoxidation network were studied experimentally over a cesium-doped silver catalyst supported on α-Al 2 O 3 pellets in a differential reactor. A variety of rate functions were considered and among these, expressions based on a dual-site Langmuir−Hinselwood mechanism: r i = k i P E /(1 + P E )…
A two-step reaction mechanism (catalyzed alternatively by acid and base) with partial proton shuttles and charge redistributions promoted by short strong H bonds (SSHBs) (playing a dual role as an amphi-acid/base catalyst) is proposed to explain the enormous rate enhancement observed in enzymatic reactions involving c…
We use a many-body, atomistic empirical pseudopotential approach to predict the multi-exciton emission spectrum of a lens shaped InAs/GaAs self-assembled quantum dot. We discuss the effects of (i) The direct Coulomb energies, including the differences of electron and hole wavefunctions, (ii) the exchange Coulomb energ…
Femtosecond transient absorption in the visible and infrared spectral ranges has been applied to study carrier dynamics and mechanisms for resonant optical nonlinearities in CdSe nanocrystals (NCs) with a variety of surface passivations. Sequential filling of the 1S, 1P, and 1D atomic-like electron orbitals, governed…