Materials Literature
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Enhanced transmission through subwavelength slit gratings and hole arrays is studied in view of its application in the far-infrared and microwave domains. Because for perfectly conducting gratings, plasmon resonances are not expected to produce an enhanced transmission, other kinds of resonance, such as Fabry-Perot, w…
${\mathrm{BaTiO}}_{3}$ and ${\mathrm{SrTiO}}_{3}$ are ceramic materials having immense technological applications. We present state-of-the-art calculations of the frequency-dependent dielectric function using the full potential linear augmented plane wave method. We find that compared to the previous calculations, our…
Abstract The effects of the size (pseudo‐generation number) and nature of end groups on physical and rheological properties were investigated for a series of hyperbranched polyesters based on an ethoxylated pentaerythritol core and 2,2‐ bis ‐(hydroxymethyl)propionic acid repeat units. The observed linear dependence of…
To lower the dielectric constant k of interlayer-dielectric films with two-dimensional pore structures while maintaining their mechanical strength, the influences of pore arrangement on the elastic modulus E and k of the films were investigated. It was found that periodicity in pore structure enhances E with constant…
Abstract An identification of shallow bound exciton centers in ZnO is presented based on magneto‐optical measurements and diffusion experiments. The thermalization behavior of the Zeeman split components confirms that the I 4 , I 6 , I 8 and I 9 exciton lines stem from donor bound exciton complexes. The results are su…
We report solution-state and solid-state 13 C NMR data for the alanine dipeptide ( N -acetyl- l -alanine- N ‘ -methylamide, AcAlaNHMe) in polycrystalline, lyophilized, and solvated states. Changes in the 13 C chemical shifts of individual carbonyl carbons between the solvated and lyophilized states for the alanine dip…
Abstract A study on the correlation between electrical percolation and viscoelastic percolation for carbon black (CB) and carbon fiber (CF) filled high‐density polyethylene (HDPE) conductive composites was carried out through an examination of the filler concentration (ϕ) dependence of the volume resistivity (ρ) and d…
The basic physical mechanisms by which different kinds of ionizing radiation interact with matter are described. Understanding of these processes, coupled with detailed knowledge of atomic structure, provides much of the foundation for the theory and practice of radiological health protection today.
We performed validation and calibration of the embedded-cluster method in order to study its applicability to modeling defects in amorphous silica, where defect models are not well established. As test systems we used well-studied ${E}_{4}^{\ensuremath{'}}$ and ${E}_{1}^{\ensuremath{'}}$ centers in $\ensuremath{\alpha…
We have studied lasing in dye-doped chiral nematic liquid crystals (N*LCs). To demonstrate the advantages of using a polymer dye, that is highly aligned along the local director of N*LCs, over commercial small molecule dyes such as 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostryl)-4H-pyran (DCM), comparative stud…
Noble Gemini surfactants containing a siloxane moiety have been designed and successfully synthesized in the present study and are utilized as structure-directing agents for mesoporous metal oxides such as zirconia, titania, and vanadia. The siloxane moiety is believed to play an important nano-propping role during th…
A cylindrical lens is demonstrated using two planar substrates and a homogeneous liquid crystal (LC) layer. The top substrate has slit electrodes on its outer surface and the bottom has a transparent electrode on its inner surface. An applied voltage across the cell induces a cylindrical-like gradient refractive index…
A detailed analysis of the polarization characteristics (birefringence) of a silicon-on-insulator (SOI) rib waveguide is given. The fundamental TE- and TM-polarized modes of the SOI rib waveguide are calculated by a semivectorial finite-difference method. The rib width and the slab height of the SOI rib waveguide are…
The microscopic structure of Langmuir films of derivatized gold nanoparticles has been studied as a function of area/particle on the water surface. The molecules (AuSHDA) consist of gold particles of mean core diameter D approximately 22 angstroms that have been stabilized by attachment of carboxylic acid terminated a…
We used both localized and periodic calculations on a series of monovalent (Li+, Na+, K+, Rb+, Cs+) and divalent (Mg2+, Ca2+, Sr2+, Ba2+) cations to monitor their effect on the swelling of clays. The activity order obtained for the exchangeable cations among all the monovalent and divalent series studied: Ca2+ > Sr2+…
Intercalation of metallic oxalato complexes CoOx 2 2 -, CuOx 2 2 -, MnOx 3 3 -, and GaOx 3 3 - in [Zn 2 Al] and [Mg 2 Al] LDHs was successfully carried out leading to well characterized products in which metallic complexes lying between layers were subjected to minor modifications following intercalation as confirmed…
L-lactide was polymerized as concentrated solution in chlorobenzene with Bi(OAc)3 as initiator. When tetra(ethylene glycol) was added as co-initiator (CoI), telechelic polylactides having two CH-OH end groups were obtained. With 1,1,1-tri(hydroxy methyl)propane (THMP) as co-initiator, three-armed stars having three CH…
Abstract Poisson's ratios of cellulose I β and cellulose II were determined for purified ramie and mercerized samples by X‐ray diffractometry. Poisson's ratio was 0.38 for [200]/[004] of cellulose I β and 0.30 for [200]/[004] and 0.46 for [110]/[004] of cellulose II. The smaller [200]/[004] Poisson's ratio for cellulo…
The fluorescence intensity from a planar multilayered system with a chromophore separated from a gold film by a dielectric spacer is measured quantitatively. The direction of excitation and the spacer thickness are varied and the angular distribution of the emission is recorded as well as its polarization. The experim…
Cantilever magnetometry has been used to measure the upper critical magnetic field H(c2) of the quasi-one-dimensional molecular organic superconductor (TMTSF)2ClO4. From simultaneous resistivity and torque magnetization experiments conducted under precise field alignment, H(c2) at low temperature is shown to reach 5 T…