Materials Literature
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Dispersive effects due to microstructure of materials combined with nonlinearities give rise to solitary waves. In this paper the existence of solitary wave solutions is proved for a rather general hierarchical governing equation which accounts for nonlinearities on both macro- and microscales. Properties of the waves…
The depth distribution of ultraviolet laser irradiation-induced defects in fused silica has been determined using cathodoluminescence (CL) microanalysis. CL emissions have been observed at 1.9, 2.2, 2.7, and 4.4 eV. In addition, following a CO2 laser treatment for damage mitigation, an emission at 3.2 eV is also obser…
Hyperbranched poly(amino ester)s were synthesized via a novel 2A 2 + BB‘B‘ ‘ approach, represented by the Michael addition polymerization of a trifunctional amine, 1-(2-aminoethyl)piperazine (AEPZ) (BB‘B‘ ‘-type monomer), with a double molar diacrylate, 1,4-butanediol diacrylate (BDA) (A 2 -type monomer). The formatio…
Here we demonstrate that the incorporation of boron (B) atoms between double-walled carbon nanotubes (DWNTs) during thermal annealing (1400-1600 degrees C) results in covalent nanotube "Y" junctions, DWNT coalescence, and the formation of flattened multiwalled carbon nanotubes (MWNTs). These processes occur via the me…
The structure of carbon nanosheets deposited by radio frequency plasma-enhanced chemical-vapor deposition at different substrate temperatures is investigated via x-ray scattering. Carbon nanosheets consist of vertically aligned graphene-layer stacks, one to nine layers thick, which can attain micron-scale lengths. His…
The local structure of sixfold oxygen coordinated silicon $(^{[6]}\mathrm{Si})$ in sodium phosphosilicate glasses has been investigated using MAS NMR spectroscopy and ab initio quantum-chemical techniques. It has been demonstrated that $^{[6]}\mathrm{Si}$ is interconnected by six $\mathrm{P}{\mathrm{O}}_{4}$ tetrahedr…
Eine sphärische Kapsel wird auf einfache Weise durch Anbinden von Verbindungsstücken an pentagonale Struktureinheiten erzeugt. Die Metallzentren M des so gebildeten {(MoVI)MoVI5}12M30-Keplerats (M=VIV, FeIII) bilden ein Ikosidodekaeder (siehe Bild). Für M=FeIII kann die magnetische Konfiguration der 30 Spin-Zentren (f…
The elastic moduli of a solid can be determined from the thermal fluctuations of the stress. The so-called stress-fluctuation approach is useful in that it can provide insights into the molecular origin of a particular mechanical response, and it leads to faster convergence than methods based on fluctuations of the st…
The interface between magnetite $({\mathrm{Fe}}_{3}{\mathrm{O}}_{4})$ and Nb-doped $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ shows typical characteristics of a Schottky barrier. The magnetoresistance was found to depend on the bias current through the junction. This can be understood within a model for a Schottky conta…
Polarization state in epitaxial thin films of relaxor ferroelectric PbMg1∕3Nb2∕3O3 (PMN) was experimentally studied at the nanoscale using a piezoresponse force microscopy (PFM). In the absence of a dc bias applied to the PFM tip, no piezoelectric activity could be found on most of the surface of the film. Under a mod…
A minimal coupling model exhibiting isotropic, uniaxial, and biaxial nematic phases is analyzed in detail and its relation to existing models known in the literature is clarified. Its intrinsic symmetry properties are exploited to restrict the relevant ranges of coupling constants. Further on, properties of the model…
The preparation of platinum (0−2 wt %) supported on ceria/zirconia (Ce 0.5 Zr 0.5 O 2 ) by flame synthesis resulted in materials with good thermal stability and improved dynamic oxygen exchange capacity at low temperatures. Comparison to a conventionally prepared material (precipitation and incipient wetness impregnat…
The most stable structure of aluminum hydride $\mathrm{Al}{\mathrm{H}}_{3}$ is believed to be a hexagonal symmetry. However, using the density functional theory, we have identified two more stable structures for the $\mathrm{Al}{\mathrm{H}}_{3}$ with the cubic and orthorhombic symmetries. Based on the quasiharmonic ap…
Novel biocompatible and biodegradable amphoteric poly(amidoamine) (PAA) hydrogels were designed for applications as scaffolds for tissue engineering. These hydrogels (PAA-AG1 and PAA-AG2) were obtained by polyaddition of 2,2-bisacrylamidoacetic acid with 2-methylpiperazine and 4-aminobutyl guanidine, a bioactive molec…
CoO x /CeO 2 nanocomposite materials with increasing Co/Ce atomic ratio were prepared by wet impregnation and characterized by means of X-ray photoelectron, diffuse reflectance infrared Fourier transform, and inductively coupled plasma atomic emission spectroscopic techniques, by BET and by thermal analysis. CoO is pr…
This study presents syntheses, structural characterization, and crystallization kinetic investigation of new structurally well-defined star-shaped poly(l-lactide)s (PLLAs). First, a series of new 3- to 6-arm star-shaped PLLAs were synthesized through SnOct(2) catalyzed ring-opening polymerization of (l)-lactide with n…
Organic dye nanoparticles 1-13 nm in height and 10-45 nm in width were prepared by the reprecipitation method. With single-molecule/nanoparticle spectroscopy, two distinct types of nanoparticles were found: particles with blue emission and particles with red emission. The difference in spectral characteristics is attr…
We report the discovery, synthesis, and crystallographic binding mode of novel furanopyrimidine and pyrrolopyrimidine inhibitors of the Chk1 kinase, an oncology target. These inhibitors are synthetically tractable and inhibit Chk1 by competing for its ATP site. A chronological account allows an objective comparison of…
The static and dynamic mechanical properties of banana and glass woven fabric-reinforced polyester composites have been determined with special reference to the effect of fiber volume fraction, layering pattern, and the weaving architecture. Even though articles related to natural fiber composites are abundant in the…
Reverse w/o microemulsions composed of methyl methacrylate (MMA) forming the oil phase, nonionic surfactants, and water are used for the synthesis of transparent SiO2/PMMA nanocomposites. An inorganic precursor, tetraethoxysilane (Si(OEt)(4), TEOS), is hydrolyzed in the reverse micelles containing aqueous ammonia. Dur…