Materials Literature
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Parity breaking instabilities of spatially periodic patterns are considered. In homogeneous systems such instabilities produce steadily drifting patterns. Spatial inhomogeneities are shown to lead to pattern pinning. The transition from pinned patterns to drifting ones may be surprisingly complex. Examples are describ…
High-resolution heat-capacity and electron-diffraction measurements have been conducted on thin free-standing films of a liquid-crystal compound exhibiting the smectic- $A$--hexatic- $B$--crystal- $B$ transitions. Despite the absence of herringbone order, the liquid-hexatic transition in extremely thin films has never…
The behaviour of FCC crystals of the metals platinum, gold, rhodium and silver under uniaxial tension was investigated using atomistic simulation. At temperatures above half the melting temperature all the model metals disordered before they failed by void formation. Investigation of the free energy as a function of o…
The results of two independent experiments in the vicinity of the ``transition'' from the third blue phase ( ${\mathrm{BP}}_{\mathrm{III}}$) to isotropic phase ( $I$) are reported for a highly chiral liquid crystal. Heat capacity measurements using a high-resolution calorimeter and dynamic light-scattering measurement…
Time-domain light scattering on ns--ms time scales has been performed on salol to probe the dynamics in the glass transition range and evaluate through a novel method the nonergodicity parameter ${f}_{q}(T)$ of mode coupling theory (MCT) in the wave vector limit $q\ensuremath{\rightarrow}0$. Stretched-exponential stru…
The lytic transglycosylases of Escherichia coli are involved in peptidoglycan metabolism and resemble the lysozymes not only in activity, but in the case of the 70 kDa soluble lytic transglycosylase (Slt70), also structurally. Here we report the cloning of the gene that encodes the 35 kDa soluble lytic transglycosylas…
Diamond films have been obtained by the hot-filament chemical vapor deposition method on a silicon wafer. The substrates were preimplanted by a Si+ ion beam (ion energy 25 keV, implantation dosage 2×1017 Si/cm2). X-ray diffraction, scanning electron microscopy, and Raman spectroscopy were used to characterize the stru…
Single-crystal films of perovskitelike (La,Ca)MnO3 with very smooth surface were grown epitaxially on (110) NdGaO3 substrates by a simple facing-target sputtering technique. Their in-plane and out-of-plane crystal structures were examined by means of a novel double-crystal x-ray diffraction technique. The c axis of th…
The nucleation of diamond on Si is enhanced for negative substrate bias of 200–250 V. We show that the ion flux is the critical factor causing the enhanced nucleation. The ion energy distribution has a maximum at about 80 eV, the optimum to subplant C ions into a-C. We propose that subplantation causes deposition of n…
Within a spectral function $A(\mathbf{k},\ensuremath{\omega})$ interpretation of angle-resolved photoemission (ARPES), the intensity obeys the sum rule $\ensuremath{\int}d\ensuremath{\omega}f\left(\ensuremath{\omega}\right)A(\mathbf{k},\ensuremath{\omega})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}n\left(\math…
The aim of the present investigation was to elucidate the role of structural relaxations in determining the relative stability of ${L1}_{2}$, ${D0}_{22}$, and ${D0}_{23}$ structures in ${\mathrm{Al}}_{3}\mathrm{Ti}$ and ${\mathrm{Al}}_{3}\mathrm{Zr}$. This task was accomplished by a unique combination of total-energy…
This work determines the pressure–velocity relation of bubble flow in polygonal capillaries. The liquid pressure drop needed to drive a long bubble at a given velocity U is solved by an integral method. In this method, the pressure drop is shown to balance the drag of the bubble, which is determined by the films at th…
Kidney bean purple acid phosphatase (KBPAP) is an Fe(III)-Zn(II) metalloenzyme resembling the mammalian Fe(III)-Fe(II) purple acid phosphatases. The structure of the homodimeric 111-kilodalton KBPAP was determined at a resolution of 2.9 angstroms. The enzyme contains two domains in each subunit. The active site is loc…
A highly ordered metal nanohole array (platinum and gold) was fabricated by a two-step replication of the honeycomb structure of anodic porous alumina. Preparation of the negative porous structure of porous alumina followed by the formation of the positive structure with metal resulted in a honeycomb metallic structur…
The Gaussian overlap model for anisotropic particles is generalized to include ellipsoids which are not axially symmetric. Explicit analytical expressions are given for the potential and for the torques necessary in molecular dynamics (MD) simulations. Employing this model, we have obtained MD results for several syst…
PbTe nanocrystals have been grown in doped glasses. By choosing the appropriate glass matrix and controlling the heat treatment temperatures and times, the quantum confined energy gaps of the PbTe dots can be changed in the wavelength range 1.1 – 2.0 µm. These glasses are potential materials for applications in optica…
The photoelectron spectra of FeO− and FeO−2 are obtained at 3.49 eV photon energy. Transitions to the ground state (5Δ) and three low-lying excited states (5Σ+, 3Σ+, and 3Δ) of FeO are observed. The two low-spin excited states found at 6770 and 8310 cm−1 above the ground state, respectively, have not been observed bef…
Abstract A method for determining the stability of general static capillary surfaces is illustrated by application to the liquid bridge. Axisymmetric bridges with fixed contact lines under gravity are parametrized by three quantities: bridge length L, bridge volume V, and Bond number B. The method delivers: (i) stabil…
Electronic structure calculations for compressed molecular hydrogen are performed to provide more insight into the diversity of phenomena recently observed experimentally. We perform full-potential LAPW calculations and analyze them in terms of a molecular tight-binding model. We show that $σ_g$ and $σ_u$ bands overla…
Abstract The migration of phthalate esters which are commonly employed for plasticizing poly(vinyl chloride) (PVC) is a significant problem in PVC‐based medical devices as well as in packaging used for food stuffs and pharmaceuticals. Medical‐grade PVC resin was treated with sodium azide in dimethylformamide (DMF) to…