Materials Literature
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We report the global minima for aluminium, gold and platinum metal clusters modelled by the Voter–Chen version of the embedded-atom model potential containing up to 80 atoms using the basin-hopping Monte Carlo minimization approach. The results show that the global minima of the Al, Au and Pt clusters have structures…
The aim of the present work is to explore the effects of ultrasound on desorption of metal ions from activated carbon. The desorption of Cu(II), Mn(II), Hg(II), and Cr(VI) from activated carbon in the absence and the presence of ultrasound is investigated. Desorption studies are performed under various conditions of t…
The NAD(P)H-mediated growth of Au nanoparticles (NPs) in the presence of ascorbic acid, AuCl4-, and cetyltrimethylammonium bromide leads to the formation of shaped NP structures consisting of dipods, tripods, and tetrapods. The shaped particles exhibit a red-shifted plasmon absorbance at lambda = 680 nm, consistent wi…
Two different soluble polymers, poly(ethylene glycol) (PEG) and poly(methacrylic acid) (PMAA), with individual functions were successfully employed in combination with a third additive, sodium dodecyl sulfate (SDS), in one system, and spherical assemblies (e.g., hollow spheres) with multiscale constructs of CaCO3 were…
Two novel dinuclear Gd(III) complexes have been synthesized, based on a xylene core substituted with diethylenetriamine-N,N,N'',N''-tetraacetate (DTTA) chelators in para or meta position. The complexes [Gd2(pX(DTTA)2)(H2O)4]2- and [Gd2(mX(DTTA)2)(H2O)4]2- both exhibit high complex stability (log K(GdL) = 19.1 and 17.0…
The electrically driven deformations of side chain nematic networks swollen by nematic solvents (nematic gels) have been investigated. The strains of freely suspended gels between electrodes were measured as a function of field strength (E) . The deformation of the gels composed of a network and solvent with identical…
Penicillin-binding protein 5 (PBP 5) from Escherichia coli is a well-characterized d-alanine carboxypeptidase that serves as a prototypical enzyme to elucidate the structure, function, and catalytic mechanism of PBPs. A comprehensive understanding of the catalytic mechanism underlying d-alanine carboxypeptidation and…
Poly(ethylene glycol) (PEG) surface grafts are used as surface coatings that impart resistance to nonspecific protein adsorption. In this work, brushes of poly(ethylene glycol), grafted to a cationic polylysine backbone and adsorbed onto mica, were investigated with the surface forces apparatus, providing direct measu…
The role of architecture and nanoenvironment in the catalytic properties of dendritic polymers containing 4-(dialkylamino)pyridines was investigated in the context of acylation reactions employing sterically demanding tertiary alcohols as substrates. Fréchet-type benzyl ether and aliphatic ester dendrimers were prepar…
Key crystallographic aspects of Ge nanowires grown in a supercritical fluid were investigated by high-resolution transmission electron microscopy. The favored <110> growth direction was attributed to the crystallographic faceting of low-energy {111} and {100} planes on the initial nucleus crystal and the exposed nanow…
The mechanism of the hydrolysis reaction of guanosine triphosphate (GTP) by the protein complex Ras-GAP (p21(ras) - p120(GAP)) has been modeled by the quantum mechanical-molecular mechanical (QM/MM) and ab initio quantum calculations. Initial geometry configurations have been prompted by atomic coordinates of a struct…
A novel ABA-type triblock copolymer, where A and B correspond to azobenzene (Az) containing polymethacrylate and poly(ethylene oxide) (PEO), respectively, was synthesized by atom transfer radical polymerization. Langmuir-Blodgett monolayers showed characteristic microphase separation structures depending on the isomer…
Addition of (LiF)$_{y<0.15}$, and of proper amount of (AgO)$_{z=0.45-0.8}$ as oxidizing agent, to (Cu,C)Ba$_{2}$Ca$_{3}$Cu$_{4}$O$_{10+d}$ superconductor is useful to control and shift the doping characteristics (hole density and distribution, and level of disorder) into the region where the irreversible properties, i…
Boron nitride (BN) nanotubes were synthesized through chemical vapor deposition over a wafer made by a LaNi5/B mixture and nickel powder at 1473 K. Scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were performed to c…
Ce3+ and Tb3+ coactivated LaPO4 nanowires and micrometer rods were synthesized by hydrothermal methods. Their fluorescent spectra and dynamics were systematically studied and compared. The results indicated that the extinction coefficients of Ce3+ and Tb3+ in nanowires were higher than those in micrometer rods. The el…
Very sharp magnetization step is observed across the field-induced antiferromagnetic-to-ferromagnetic transition in various doped $\mathrm{Ce}{\mathrm{Fe}}_{2}$ alloys, when the measurement is performed below $5\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. In the higher temperature regime $(T>5\phantom{\rule{0.3em}{0ex}}…
The dynamics of spin-lattice relaxation of the Mn-ions in (Zn,Mn)Se-based diluted-magnetic-semiconductor quantum wells is studied by time-resolved photoluminescence. The spin-lattice relaxation time varies by five orders of magnitude from 10-3 down to 10-8 s, when the Mn content increases from 0.4 up to 11%. Free carr…
We study the massless limit of the Klein-Gordon (K-G) equation in 1+1 dimensions with static complex potentials as an attempt to give an alternative, but equivalent, representation of plane electromagnetic (em) wave propagation in active medium. In the case of dispersionless em medium, the analogy dictates that the po…
By means of extensive first-principles calculations we studied the ferroelectric phase transition and the associated isotope effect in $\mathrm{K}{\mathrm{H}}_{2}\mathrm{P}{\mathrm{O}}_{4}$ (KDP). Our calculations revealed that the spontaneous polarization of the ferroelectric phase is due to electronic charge redistr…
Hierarchically ordered mesocellular mesoporous silica materials (HMMS) were synthesized using a single structure-directing agent. The mesocellular pores are synthesized without adding any pore expander; the pore walls are composed of SBA-15 type mesopores. Small-angle X-ray scattering revealed the presence of uniform…