Materials Literature
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A complex analysis of the nonlinear diffusion problem in ferromagnetic materials under steady-state excitation is presented. The problem is solved by considering an equivalent fictitious material where the relative permeability is assumed to be constant in time but different from point to point and is related to the n…
We study the failure properties of a defected square lattice of Born springs under uniaxial tensile strain. The springs fail completely and irreversibly once a critical strain energy is exceeded. The Born potential provides an effective bending force that yields realistic crack microstructures, which are analyzed in d…
We consider the partial differential equation which describes phase separation in a block copolymer melt. We construct numerically the periodic solution which minimizes the free energy. The lamellar thickness of the final equilibrium pattern is found to scale with the molecular weight as a power law ${\ensuremath{\lam…
Metal silos and tanks are subject to axial compressive stresses in their cylindrical shell walls. The buckling strength is very sensitive to geometric imperfections in the wall. The most regular and well‐defined imperfection is the local depression adjacent to a circumferential weld, caused by the plate rolling proces…
The processing problems associated with boron carbide and the limitations of its mechanical properties can be significantly reduced when a metal phase (e.g., aluminum) is added. Lower densification temperatures and higher fracture toughness will result. Based on fundamental capillarity ther modynamics, reaction thermo…
We obtain explicit predictions for velocity selection in two- and three-dimensional, symmetric, and one-sided models of dendritic solidification. We do this by using WKB techniques to derive a solvability condition, which is then solved numerically, for the existence of steady-state needle crystals. The comparison wit…
Defects are local breakings of symmetry in an ordered medium. The physics of defects has long been reduced to the study of dislocations in solids, and to the main physical phenomena they are responsible for, like plastic deformation. Dislocations break translational symmetries. Disclinations break rotational symmetrie…
We present a study which reveals that the switching speed for the redox reaction of polyaniline is very fast. With a 1200Å film in 2 M sulfuric acid, switching speeds of up to 100 μs with current densities of 100 A/cm 2 are observed with the appropriate compensation for IR loss. The true switching speed is higher stil…
Summary The mobilities of aqueous foams of known texture have been measured in homogeneous bead packs. To correlate the data, a theory developed recently to describe the apparent viscosity of foams in smooth capillaries is extended to account for (1) the capillary pressure imposed by the porous medium and (2) constric…
A review is given of some simplified concepts that will contribute to a better understanding of corrosion fundamentals. The corrosion process involves not only electrochemical reactions but also acid-base reactions, and it is the acid-base nature that diversifies the corrosion phenomena. Anions either catalyze or inhi…
Several techniques are reviewed with which thermal conductivity and phonon scattering can be measured in films of thicknesses ranging from angstroms to millimeters. Recent experimental results are compared critically with previous measurements. It is shown that phonons are very sensitive probes of the structural perfe…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTransition-metal-catalyzed epoxidationsKarl Anker JoergensenCite this: Chem. Rev. 1989, 89, 3, 431–458Publication Date (Print):May 1, 1989Publication History Published online1 May 2002Published inissue 1 May 1989https://doi.org/10.1021/cr00093a001RIGHTS & PERMISSIONSArticle…
Surface property studies of high-strength and high-modulus carbon fibers indicate that they possess higher surface free energies than previously believed. London dispersion components of the surface free energy were calculated from the increment per methylene group in the free energy of adsorption of n-alkanes at zero…
We have investigated the formation of 〈110〉 oriented fivefold diamond microcrystallites on {001} silicon substrates using high-resolution transmission electron microscopy (HRTEM). The HRTEM micrographs clearly show that fivefold symmetry in diamond microcrystallites results from twinning in {111} planes, in agreement…
The magnetic properties of YFe 2 were investigated using the polarised neutron technique. Flipping ratios were measured for the first five reflections of a powder. The magnetic intensity on the (220) reflection proved that the yttrium site carries a magnetic moment antiparallel to that of the iron site. The results we…
A transmission-electron-microscope technique enables direct visualization of the director field of a liquid-crystal polymer at a resolution of 30 nm. Continuum mechanics is used to describe distortions in the director field produced by a disclination, and the relative bend and splay elastic anisotropy for various poly…
Photoluminescence measurements of the 1.9 eV emission were carried out on high-purity silica glasses subjected to γ-ray irradiation. The time decay of the luminescence, when excited by the 4.8 eV band, indicates that the 4.8 eV absorption and the 1.9 eV luminescence are caused by two different defects, and that an ene…
The surface structure of ${\mathrm{SrTiO}}_{3}$(100) was analyzed at T=120 K by means of low-energy-electron diffraction. The best theory-experiment fit results for a surface containing domains of two different layer terminations. Both of them show a first-layer puckering with oxygen ions being pulled out of the surfa…
As another new high quality nonlinear optical (NLO) crystal of the borate series, lithium triborate LBO has been characterized in our Fujian Institute. This follows theoretical calculations of the second harmonic generation (SHG) coefficients on the basis of the anionic group theory (which has been generalized into a…
The analysis of the electronic properties of the tight-binding Fibonacci Hamiltonian is carried out using dynamical systems techniques. Two classes of Fibonacci sequences are considered, corresponding to the cases when there are two types of building blocks and also when there are three types of building blocks. The r…