Materials Literature
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Transition metal doped III-V, II-VI, and group IV compounds offer an unprecedented opportunity to explore ferromagnetism in semiconductors. Because ferromagnetic spin-spin interactions are mediated by holes in the valence band, changing the Fermi level using co-doping, electric fields, or light can directly manipulate…
The present investigation describes the synthesis and characterization of novel biodegradable nanoparticles based on chitosan. Poly(ethylene glycol) dicarboxylic acid was used for intramolecular cross-linking of the chitosan linear chains. The condensation reaction of carboxylic groups and pendant amino groups of chit…
Big is beautiful: A folded synthetic molecule with a conformation that compares in size with the tertiary folds of a small protein and yet only consist of non-natural units is described. By not controlling the helical handedness allows the effect of tertiary interactions between helical modules through helix–helix sid…
The antibacterial activity of ciprofloxacin-encapsulated silica nanoshells synthesized from gold@silica core-shell nanoparticles has been investigated. The minimum inhibitory concentration of the material was found using the agar dilution method, and it showed better antibacterial activity compared to free ciprofloxac…
Bacterial transport of many sugars, coupled to their phosphorylation, is carried out by the phosphoenolpyruvate (PEP):sugar phosphotransferase system and involves five phosphoryl group transfer reactions. Sugar translocation initiates with the Mg(2+)-dependent phosphorylation of enzyme I (EI) by PEP. Crystals of Esche…
Electron paramagnetic resonance (EPR) studies of a ${\mathrm{Ni}}_{4}$ single-molecule magnet (SMM) yield the zero-field-splitting (ZFS) parameters $D$, ${B}_{4}^{0}$, and ${B}_{4}^{4}$, based on the giant spin approximation (GSA) with $S=4$; ${B}_{4}^{4}$ is responsible for the magnetization tunneling in this SMM. Ex…
Electronic structure of boron-nitride nanotubes (BNNTs) can be tuned in a wide range through covalent functionalization, as experimentally and theoretically evidenced. Various functional groups were covalently attached to BNNTs. The ultraviolet-visible absorption spectra indicate that the electronic structure of BNNTs…
The synthesis of peptide−polymer conjugates comprising ( d - alt - l )-cyclopeptides as aggregator domains and their self-assembly into tubelike structures is described. By coupling two well-defined poly( n -butyl acrylate) blocks to opposite sides of a preformed cyclic ( d - alt - l )-α-octapeptide, a coil−ring−coil…
Effects of the structure of an alkoxysilane on the early reaction kinetics of sol-gel polymerization are investigated in basic and acidic conditions. Six silanes, including tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), methyltrimethoxysilane (MTMS), bis(trimethoxysilyl)ethane (BTMSE), bis(trimethoxysilyl)hexane…
The second hyperpolarizability $γ_N(-3ωω,ω,ω)$ of $N$ double-bond finite chain of trans-polyactylene is analyzed using the Su-Schrieffer-Heeger model to explain qualitative features of the size-dependence behavior of $γ_N$. Our study shows that $γ_N/N$ is {\it nonmonotonic} with $N$ and that the nonmonotonicity is cau…
Abstract An amine‐terminated hyperbranched polyimide (HBPI) was prepared by the condensation polymerization of a commercially available triamine monomer with a dianhydride monomer. The effects of the HBPI content on the thermal and mechanical interfacial properties of diglycidyl ether of bisphenol A (DGEBA) epoxy resi…
Abstract A Brabender mixer was used to deagglomerate and disperse organomodified montmorillonite Cloisite® 30B (3 wt %) in polylactide (PLA) matrix to obtain nanocomposite systems. The influence of compounding conditions such as blending time (6.5, 10, 20, and 30 min) and compression molding on the nanostructure of na…
We show a novel magneto-resistive effect that appears in lithographically shaped, three-arm nanostructure, fabricated from ferromagnetic (Ga,Mn)As layers. The effect, related to a rearrangement of magnetic domain walls between different pairs of arms in the structure, reveals as a dependence of zero-field resistance o…
We report the magnetocaloric effect in terms of isothermal magnetic entropy change as well as adiabatic temperature change, calculated using the heat capacity data. Using the zero field heat capacity data, the magnetic contribution to the heat capacity has been estimated. The variations in the magnetocaloric behavior…
Over the past five years, considerable work has been carried out in the exploration of candidate diluted oxide magnetic semiconductors with high Curie temperatures. Fueled by early experimental results and theoretical predictions, claims of ferromagnetism at and above room temperature in doped oxides have abounded. In…
The emission properties of nanocrystalline ZnO particles prepared following an organometallic synthetic method are investigated. Spherical particles and nanorods are studied. The shape of the particles and the ligands used are shown to influence the luminescence properties in the visible domain. Two different emission…
The creation of a highly enhanced electromagnetic (EM) field underneath a scanning tunneling microscope (STM) tip enables Raman spectroscopic studies of organic submonolayer adsorbates at atomically smooth single crystalline surfaces. To study the sensitivity of this technique, tip-enhanced resonance Raman (TERR) spec…
We argue that a pseudo-one-dimensional electron gas is magnetized when a voltage bias is applied with the Fermi level tuned to be in the energy gap generated by a spin-orbit interaction. The magnetization is an indication of spin-carrying currents due to the spin-orbit interaction. The origin of the magnetization, how…
We propose a simple equation for predicting self-diffusivity of fluids embedded in random matrices of identical, but dynamically frozen, particles (i.e., quenched-annealed systems). The only nontrivial input is the volume available to mobile particles, which also can be predicted for two common matrix types that refle…
Understanding the detailed electronic structure of deep defect states in narrow band-gap semiconductors has been a challenging problem. Recently, self-consistent ab initio calculations within density functional theory using supercell models have been successful in tackling this problem. In this paper, we carry out suc…