Materials Literature
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Cryoprocessing is the process of cooling a material to extremely low temperatures to generate enhanced mechanical and physical properties. This article examines the effects of cryoprocessing on steel and some copper alloys. Research has shown that improvements occur in wear resistance, dimensional stability, electrica…
The X-ray crystal structure and magnetic properties of a molecular crystal consisting of 1,5-dimethyl-3-(2-pyridyl)-6-oxoverdazyl radical and hydroquinone (pyvd:hq) are presented. The structure contains a two-dimensional network of hydrogen bonds involving the hydroquinones and the pyridine ring of the pyvd radical. T…
The Langmuir-Blodgett (LB) technique has been used to obtain spatially resolved surface-enhanced resonance Raman scattering (SERRS) spectra of single dye molecules dispersed in the matrix of a fatty acid. The experimental results presented here mimic the original electrochemical surface-enhanced Raman scattering (SERS…
Mechanisms of electron phase separation in manganite-type oxide materials are analyzed using a simple Kondo-lattice model with intersite Coulomb repulsion between electrons. This model predicts the instability of magnetic (or charge) homogeneous ordering toward the formation of droplet structures (magnetic polarons) f…
By use of the analytic result for the Laplace transform of the radial distribution function for two large hard spheres dispersed in a fluid of the smaller hard spheres, simple equations for the film interaction energy and film disjoining pressure, due to the structural and depletion forces, are derived. The proposed e…
Organically modified transition-metal oxide clusters (OMTOCs) are structurally well-defined nanosized building blocks for the preparation of a new type of inorganic−organic hybrid materials. There are two principal methods to synthesize OMTOCs with polymerizable organic groups attached to their surface: the groups can…
Luminescent lanthanide chelates have unusual spectroscopic characteristics that make them valuable alternative probes to conventional organic fluorophores. However, fundamental parameters such as their quantum yield, and radiative and nonradiative decay rates have been difficult or impossible to measure. We have devel…
Zinc(II) and cadmium(II) coordination networks with p -pyridinecarboxylate bridging ligands, Zn(4-pyridylacrylate) 2 ( 3), [Cd(4-pyridylacrylate) 2 ]·H 2 O ( 4), Cd[4-(4-pyridyl)benzoate] 2 ·H 2 O (5), and [Zn 2 (μ-OH)(4-pyridylbenzoate) 3 ]·EtOH (6), have been synthesized under hydro(solvo)thermal conditions. Despite…
With increasing clock speed, the scaling of CMOS transistor geometries presents ever more severe challenges to the maintenance of operational circuits. As the gate area is reduced, the thickness of the gate dielectric must also be reduced in order to maintain sufficient capacitative control of the MOS channel for adeq…
The ultrasonic (longitudinal and transverse) velocities and the transport and magnetic properties of polycrystalline La 0.25 Ca 0.75 Mn 1- x Cr x O 3 ( x = 0, 0.03, 0.05, and 0.07) have been studied systematically. It was found that with increasing Cr content, the resistivity increases, the charge-ordering transition…
The enzyme chorismate lyase (CL) catalyzes the removal of pyruvate from chorismate to produce 4-hydroxy benzoate (4HB) for the ubiquinone pathway. In Escherichia coli, CL is monomeric, with 164 residues. We have determined the structure of the CL product complex by crystallographic heavy-atom methods and report the st…
Abstract Morphology development during isothermal crystallization in equal molecular weight isotactic polypropylene ( i PP), syndiotactic polypropylene ( s PP), and i PP/ s PP blends was studied with time‐resolved simultaneous small‐angle X‐ray scattering (SAXS) and wide‐angle X‐ray diffraction (WAXD) with synchrotron…
The effects of the variation of different parameters in some hydrophobically modified polyacrylamides in aqueous polymer solution on their surface properties have been investigated. Two different hydrophobes, N, N -dihexylacrylamide (DiHexAM) and N -(4-butylphenyl)acrylamide (BPAM), have been used; the former was most…
The production of a microelectronic circuit is a complex operation, performed by dedicated, expensive machines that coat, expose, bake, develop, etch, strip, deposit, planarize, and implant. Each of these process steps must be executed by design in order for the final product to function properly. For controlling a pr…
We study the surface morphology evolution of ZnO films grown by pulsed laser deposition. Atomic force microscopy measurements show the existence of two growth regimes. Initially, the growth morphology is determined by shadowing effects due to the angular spreading of the plume in the 0.1 mbar oxygen working pressure.…
Abstract The objective of this work was to use both X‐ray and differential scanning calorimetry techniques in a comparative study of the lamellar and crystalline structures of heterogeneous and homogeneous ethylene‐α‐copolymers. The samples differed in the comonomer type (1‐butene, 1‐hexene, 1‐octene, and hexadecene),…
We report the structural solution of a one-dimensional ${\mathrm{Sb}}_{2}{\mathrm{O}}_{3}$ crystal incorporated within a helical (21,-8) single-walled carbon nanotube. The structures of both the encapsulated crystal and nanotube have been quantified using the phase image recovered via a modified object wave restoratio…
Short chains of Au 55 (PPh 3 ) 12 Cl 6 clusters were generated between tungsten tips on an SiO 2 surface, and their electrical behavior was studied. The clusters were deposited from solution by applying a voltage of 2 V between tips of 30 nm in distance. Current−voltage (I−V) measurements of the nanowires showed Coulo…
Electron spin echoes were performed on nitrogen-vacancy $(\mathrm{N}\ensuremath{-}V)$ centers in diamond using optical polarization and detection and 35 GHz microwave control. The experiments demonstrate an approach to quantum information in the solid state. A phase memory time of $3.6 \ensuremath{\mu}\mathrm{s}$ was…
Raman spectra were obtained from thin bundles containing just a few single-wall carbon nanotubes (SWNTs). These spectra exhibit new characteristics absent in the ensemble Raman measurements. A large variation in the radial breathing mode (RBM) Stokes to anti-Stokes Raman intensity ratio was observed for different meta…