Materials Literature
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Summary The surface composition of particles present in the fine earth (< 2 mm) of 50 soil horizons differing in composition and pedogenetic origin (13 soil profiles) was analysed by X‐ray photoelectron spectroscopy (XPS) to assess the capability and limitations of this technique and to gain better knowledge of the…
The catalytic epoxidation of cyclohexene by iron(III) porphyrin complexes and H2O2 has been investigated in alcohol solvents to understand factors affecting the catalyst activity in protic solvents. The yields of cyclohexene oxide and the Fe(III/II) reduction potentials of iron porphyrin complexes were significantly a…
A visible-blind ultraviolet (UV) photodetector (PD) with metal-semiconductor-metal (MSM) structure has been developed on a cubic-crystalline SiCN film. The cubic-crystalline SiCN film was deposited on Si substrate with rapid thermal chemical vapor deposition (RTCVD). The optoelectron performances of the SiCN-MSM PD ha…
High-quality double-walled carbon nanotubes (DWNTs) have been produced by catalytic decomposition of benzene over Fe−Mo/Al 2 O 3 catalyst at 900 °C. The produced carbon materials are DWNT bundles free of amorphous carbon covering on the surface. DWNTs have inner tube diameters in the range of 0.69−2.53 nm and outer tu…
Until now, structures that exhibited negative-refractive-index properties were 3D in form and employed resonant elements. It is widely believed that such resonant elements are essential. The present paper introduces two new features: non-resonant elements in the periodic array, and the adaptation of these ideas to pla…
Peptide models have proved important in defining the structural features of the collagen triple-helix. Some models are based on multiple repeats of a given tripeptide unit, while a host-guest design includes an individual tripeptide unit substituted within a constant repeating Pro-Hyp-Gly framework. In the present stu…
It has been long recognized that surface properties are of paramount importance for a broad range of materials and a large variety of devices. The recent development of nanoscience and nanotechnology has opened up novel fundamental and applied frontiers in surface functionalization and characterization. At the nanomet…
We have investigated the Jahn-Teller transition accompanied by the orbital order-disorder transition in ${\mathrm{LaMnO}}_{3}$ by high temperature x-ray powder diffraction with synchrotron radiation and also neutron powder diffraction. The unit cell volume of ${\mathrm{LaMnO}}_{3}$ decreases with increasing temperatur…
A branch-line coupler (BLC) working at two arbitrary frequencies using left-handed (LH) transmission lines (TLs) is presented. The analysis of the structure is based on the even-odd mode analysis of the conventional BLC as well as a recently developed model for the LH-TL. We demonstrate that the two operating frequenc…
The rate-dependent hysteresis existing in magnetostrictive actuators presents a challenge in control of these actuators. In this paper we propose a novel dynamical model for the hysteresis in a thin magnetostrictive actuator. The model features the coupling of the Preisach operator with an ordinary differential equati…
It is suggested that extrinsic inhomogeneities in mixed-valence manganites deserve more attention and they should be taking into account on equal footing with hypothetical phase separation while examinating experimental data and developing the theoretical models of influence of stoichiometric and other types of inhomo…
An exact integro-differential equation for the conformal map from the unit circle to the boundary of an evolving cavity in a stressed 2-dimensional solid is derived. This equation provides an accurate description of the dynamics of precursors to fracture when surface diffusion is important. The solution predicts the c…
Mechanically bent nickel nanowires show clear features in their room temperature magnetoresistance when a domain wall is pinned at the location of the bend. By varying the direction of an applied magnetic field, the wire can be prepared either in a single-domain state or a two-domain state. The presence or absence of…
Using elastic and inelastic neutron scattering, we investigated the evolution of the local atomic structure and lattice dynamics of La(1-x)Sr(x)CoO3 (x=0-0.5) as it crosses over with x from an insulator to a ferromagnetic metal (FMM). Our pair density function analysis indicates that in the paramagnetic insulating (PM…
We present a method to create spin-polarized beams of ballistic electrons in a two-dimensional electron system in the presence of spin-orbit interaction. Scattering of a spin-unpolarized injected beam from a lithographic barrier leads to the creation of two fully spin-polarized side beams, in addition to an unpolarize…
This research reports the use of organic-modified mesoporous silica particles as fillers to form organic/inorganic nanocomposites with improved thermal and mechanical properties. The particle fillers were synthesized by co-assembly of surfactant and silicate species prepared by hydrolysis and condensation reactions of…
6(A),6(D)-Bis-(2-amino-2-carboxylethylthio)-6(A),6(D)-dideoxy-beta-cyclodextrin 1, a diamino acid derivative of beta-cyclodextrin, is synthesized and condensed with difunctionalized PEG comonomers to give linear, high molecular weight (M(w) over 50 kDa) beta-cyclodextrin-based polymers (2-4) with pendant functionality…
This paper presents practical techniques for determining stray capacitances in a two-winding high frequency transformer for circuit simulation and computer-aided design purposes. These techniques fall into two categories: The two-port network approach; and the step-response approach. The first approach can be employed…
This paper is composed of two parts. In the first part, the fundamentals of ideal transmission lines (TL) meta-materials (NM) with their physical characteristics and the synthesis of practical artificial TL-MMs with their circuital characteristics are presented. A microstrip implementation of a composite right/left ha…
Estimating the number of molecules in the crystallographic asymmetric unit is one of the first steps in a macromolecular structure determination. Based on a survey of 15641 crystallographic Protein Data Bank (PDB) entries the distribution of V(M), the crystal volume per unit of protein molecular weight, known as Matth…