Materials Literature
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The crystal structure of zeolite NaX (Si:Al = 1.2) and that of its complex with benzene have been determined at 5 K by Rietveld analysis of powder neutron diffraction data in space group Fd 3. For NaX, a = 25.0328(5) Å, R wp = 4.25%, and R p = 3.27%. For NaX + benzene, a = 25.0496(7) Å, R wp = 4.60%, and R p = 3.52%.…
In this paper we present a classical Monte Carlo simulation of the orthorhombic phase of crystalline polyethylene, using an explicit atom force field with unconstrained bond lengths and angles and periodic boundary conditions. We used a recently developed algorithm which apart from standard Metropolis local moves empl…
We propose a new model for the chromic mechanism in amorphous tungsten oxide films ( WO 3 − y ⋅ n H 2 O ) . This model not only explains a variety of seemingly conflicting experimental results reported in the literature that cannot be explained by existing models, it also has practical implications with respect to imp…
We describe subwavelength surfaces etched into silicon wafers that exhibit antireflection characteristics for visible light. The wafers are fabricated by holographically recording a crossed-grating in a photoresist mask followed by reactive-ion etching to transfer the primary mask onto the silicon substrate. The depen…
A hard sphere system confined between two parallel hard plates is investigated theoretically. Using extensive Monte Carlo computer simulations, the phase diagram is calculated for the whole range of densities and plate separations ranging from one to two particle diameters. There occurs a strong first-order fluid free…
Thin organic films fabricated by the successive deposition of the polyelectrolytes poly(allylamine hydrochloride) (PAH) and poly(styrenesulfonate) (PSS) have been successfully grown up to 24 layers on gold surfaces. These films are formed via electrostatic attraction between adjacent layers of opposite charge. Their c…
The current techniques for X-ray-diffraction data collection from macromolecular crystals at cryogenic temperatures are reviewed. The development of the experimental methods is outlined and the basic concepts pertaining to radiation damage and cryoprotection are summarized. Emphasis is placed on the practical aspects…
The undoped lanthanum manganite system of nominal composition ${\mathrm{LaMnO}}_{3}$ has been analyzed by neutron powder diffraction for different sample heat treatment methods. Four distinct crystallographic phases have been identified: (i) an orthorhombic phase of space group Pnma and lattice parameters (at 300 K) a…
Electrochemical capacitors can be divided into two types depending on whether the salt concentration in the electrolyte changes during charging and discharging. In the first type of capacitor, such as double‐layer capacitors, the salt concentration in the electrolyte reduces during the charging of the capacitor. The m…
The effect of specific chemical functionalities on the growth of bovine aortic endothelial cells (BAEC) was investigated using a set of well-characterized, chemically functionalized surfaces prepared by self-assembly of alkanethiolate monolayers on gold surfaces using the molecules X(CH 2 ) 15 SH with X = −CH 3, −CH 2…
Nonstoichiometric cadmium sulfide nanoparticles ([Cd 2+ ]/[S 2 - ] = 3) in 2-propanol were surface-modified with Cu 2+ ions. Addition of copper(II) perchlorate to CdS nanoparticles leads to binding of copper ions onto the surface of the semiconductor, accompanied by rapid reduction of Cu 2+ to Cu +, as confirmed by EP…
Improvement in the thermal conductivity of aluminum nitride (AlN) can be realized by additives that have a high thermodynamic affinity toward alumina (Al 2 O 3 ), as is clearly demonstrated in the aluminum nitride‐yttria (AlN‐Y 2 O 3 ) system. A wide variety of lanthanide dopants are compared at equimolar lanthanide o…
Summary Sorption on the mineral matrix is an important process restricting the movement of dissolved organic matter (DOM) in soils. In this study, we aimed to identify the chemical structures responsible for the retention of DOM by sorption experiments with total DOM and acidic humic substances (AHS), containing humic…
Abstract The standard form of the Scherrer equation, which has been used to calculate the mean thickness of the coherent scattering domain (CSD) of illite crystals from X-ray diffraction (XRD) full width data at half maximum (FWHM) intensity, employs a constant, K sh , of 0.89. Use of this constant is unjustified, eve…
Alternating polyelectrolyte films constructed by the sequential adsorption of poly(allylamine hydrochloride) (PAH) and poly(styrenesulfonate) (PSS) have been used as substrates for the immobilization of immunoglobulin G (IgG) and anti-IgG. Anti-IgG has also been immobilized in multilayer films by the alternate deposit…
The piezoelectric properties of relaxor based ferroelectric single crystals, such as Pb(Zn1/3Nb2/3)O3- PbTiO3 (PZN-PT) and Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) were investigated for electromechanical actuators. In contrast to polycrystalline materials such as Pb(Zr, Ti)O3 (PZTs), morphotropic phase boundary (MPB) composit…
The spectroscopic behavior of colloidal InP quantum dots (QDs) has been investigated as a function of the mean QD diameter (which ranged from 26 to 60 Å). Absorption spectra show up to three peaks or shoulders which reflect excited state transitions in the QDs. Global photoluminescence (PL) spectra (excitation well to…
Summary The small organic matter content of mineral soils makes it difficult to obtain 13 C and 15 N nuclear magnetic resonance (NMR) spectra with acceptable signal‐to‐noise ratios. Subjecting such samples to hydrofluoric acid removes mineral matter and leads to a relative increase in organic material. The effect of t…
Monocytes are activated during collateral artery growth in vivo, and monocyte chemotactic protein-1 (MCP-1) has been shown to be upregulated by shear stress in vitro. In order to investigate whether MCP-1 enhances collateral growth after femoral artery occlusion, 12 rabbits were randomly assigned to receive either MCP…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolyhaloporphyrins: Unusual Ligands for Metals and Metal-Catalyzed OxidationsDavid Dolphin, Teddy G. Traylor, and Lily Y. XieView Author Information Department of Chemistry, University of British Columbia, Vancouver, Canada V6T 1Z1, and Department of Chemistry, University of…