Materials Literature
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The method of calculating distributed polarizabilities is extended to the first and second dipole hyperpolarizabilities, in order to describe more accurately the molecular response to strong and inhomogeneous external time-dependent electric fields. The dipolar response is expressed in terms of both potential related…
The AM1 scheme extended to d orbitals, AM1/d, has been parametrized for molybdenum. Computational results on structures and energetics of a series of molybdenum compounds are compared with experimental data. The mean absolute error of bond lengths is 0.044 Å (83 comparisons) and that of X−Mo−Y angles is 3.3° (65 compa…
A series of experiments and simulations that vary the texture and microstructure simultaneously are used to establish the role of the microstructure in texture formation in FCC metals. The stacking fault energy (SFE) of the metal, which is known to have a strong impact on texture and microstructure, is the vital param…
The theoretical ab initio studies of the singlet states of salicylideneaniline (SA) are presented. The enol, cis-keto and trans-keto tautomers were treated by the HF/6-31G* (geometries and force fields of the ground states), and the CIS (excited states), methods. For the dynamic calculations of the rates of proton tra…
AC and DC electrical measurements between 273 and 800 K were used to characterize the electrical conductivity of Al_2 O_3:Mg single crystals containing [Mg]^{0} center. At low fields contacts are blocking. At high fields, electrical current flows steadily through the sample and the I-V characteristic corresponds to a…
Because outdoor insulating materials in service are subjected to numerous wet and dry cycles, it is necessary to establish their performance in acid rain. The erosion effect of acid rain on atactic polystyrene insulating material is investigated using accelerated ageing by artificial acid rain. The degradation mechani…
Nanoparticle pair structures composed of metal (Au) and semiconductor (AgI) segments with radii ca. 16 nm have been prepared in porous anodic aluminum oxide via electrochemical template synthesis. The metal and semiconductor members can be prepared such that they are in contact or separated in the porous host. UV/visi…
A series of novel second-order nonlinear opitcal (NLO) thermoset polymers containing silicon-perfluorocyclobutane (PFCB) has been developed. The synthesis was accomplished using the cross-linking reaction between the di(trifluorovinylether)-containing NLO chromophores and the tris(trifluorovinylether) monomer in a sol…
Tungsten trioxide films were deposited on (100) SrTiO 3 and R-plane (10 2) cut sapphire substrates by dc magnetron sputtering, using a tungsten target in an Ar/O 2 sputtering gas mixture at substrate temperatures ranging from 500 to 850 °C. Deposited films were characterized by x-ray diffraction using -2 scans and pol…
Dispersed rheology of lipophilized-smectite (SAN)/toluene (TOL) suspensions with various concentrations φ of (0.03−3.77) × 10 - 2 vol fraction was examined by a stress-controlled rheometer and Ubbelohde type viscometer. Under the quiescent state of the SAN/TOL suspensions, the original laminate structure in the solid…
Sulfated zirconia (S−ZrO 2 ) is a well-known solid superacid used as a catalyst in various reactions of commercial importance such as isomerization, Friedel−Crafts alkylation and acylation, nitration, cracking, esterification, etc. S−ZrO 2, per se, is not a shape-selective catalyst. The selectivity toward the formatio…
Template condensation on iron(II) ion of dichloroglyoxime (H2C12Gm) with (C6H5O)3, n-C4H9B(O-n-C4H9)2, and BF3.O(C2H5)2 in CH3NO2 afforded reactive clathrochelate precursors Fe(C12Gm)3(BC6H5)2 (2), Fe(C12Gm)3(B-n-C4H9)2 (3), and Fe(C12Gm)3(BF)2 (4). A series of triribbed-functionalized clathrochelate dioximates have b…
A gas-phase purification method for raw nanotube material has been developed which incorporates a chlorine, water, and hydrogen chloride gas mixture to remove unwanted carbon. The evolved gases can be easily monitored by infrared spectroscopy to follow the cleaning process. The quality of the final material was verifi…
A thermodynamic model of electrolyte solutions has been used as a tool for equilibrium calculations in the Na−Bi−Ti−H 2 O and K−Bi−Ti−H 2 O systems. To perform the calculations, unknown standard-state properties for Na 0.5 Bi 0.5 TiO 3 (NBT), K 0.5 Bi 0.5 TiO 3 (KBT) and other solid compounds that exist in these syste…
The temperature dependence of structural properties for infinitely long gold nanowires is studied. The molecular dynamics simulation method and the embedded-atom potential are used. The wires constructed at T=0 K with a face-centered cubic structure and oriented along the (111), (110), and (100) directions are investi…
The wetting behavior of thin films of symmetric poly(styrene- block -methyl methacrylate) was investigated on self-assembled monolayers (SAMs) of octadecyltrichlorosilane (OTS) that were chemically modified by exposure to X-rays in the presence of air. The concentration of aldehyde and hydroxyl groups on the surface o…
We investigate short-range order and local atomic configuration in charge-balanced aluminosilicate glasses as functions of composition, using 17 O and 27 Al MAS and triple-quantum magic angle spinning (3QMAS) NMR spectroscopy. Enhanced resolution in 17 O and 27 Al 3QMAS spectra, compared to MAS NMR, allows the quantif…
We study theoretically using scaling arguments the behavior of polyelectrolyte gels in poor solvents. Following the classical picture of Katchalsky, our approach is based on single chain elasticity but it accounts for the recently proposed pearl-necklace structure of polyelectrolytes in poor solvents. The elasticity b…
A specially designed solid-state deuterium nuclear magnetic resonance probe was used to examine the effect of uniaxial elongation on the chain mobility in the amorphous region of semicrystalline nylon 6. In measurements conducted near the glass transition temperature, there was measurable deformation-induced enhanceme…
Mesoporous molecular sieves of MCM-48 type were prepared by conventional hydrothermal and novel room temperature syntheses. Scanning electron microscopy (SEM) studies have shown that nonagglomerated uniform spheres of size ca. 0.5 μm were obtained by the room temperature method. Internal pore structure was studied by…