Materials Literature
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Ovocleidin-17 (OC17) from Gallus gallus is one of the best candidates to control and regulate the deposition of calcium carbonate in the calcified eggshell layer. Here, the crystal structure of monomeric OC17, determined at a resolution of 1.5 A, was refined to a crystallographic R-factor of 20.1%. This is the first p…
Cellulose paper and an aqueous‐based, inexpensive TiO 2 precursor, Tyzor‐LA, have been used to prepare TiC via carbothermal reduction in an Ar flow. The hierarchical cellulose structures were completely maintained upon the agglomeration of 10–50 nm TiC nanoparticles. The lattice parameter of TiC increased with increas…
Multi wall carbon nanotubes (MWCNTs) or single wall carbon nanotubes (SWCNTs) were used as fillers in polyethylene (PE). Only MWCNTs reduced the heat release rates caused by polymer degradation. MWCNTs can be more effective in heat release reduction than organoclays. The char generated by the filler blend ‘MWCNTs and…
Adsorption isotherms, isosteric heats of adsorption, and neutron diffraction measurements of hydrogen, methane, argon, oxygen, and carbon dioxide adsorbed on single-wall carbon nanotube bundles show that all species, except $\mathrm{C}{\mathrm{O}}_{2}$, condense first on high-energy binding sites, such as the grooves…
An emulsion encapsulation and shrinkage technique for producing large quantities of colloidally stable clusters of microspheres (see Figure) is demonstrated. In spite of differences in particle properties and interactions, the sequence of cluster packings remains the same for three different systems, suggesting that t…
We describe a semiconductor multilayer structure based in acoustic phonon cavities and achievable with MBE technology, designed to display acoustic phonon Bloch oscillations. We show that forward and backscattering Raman spectra give a direct measure of the created phononic Wannier-Stark ladder. We also discuss the us…
We consider electron tunneling from a nonmagnetic $n$-type semiconductor ($n$-S) into a ferromagnet (FM) through a very thin forward-biased Schottky barrier resulting in efficient extraction of electron spin from a thin $n$-S layer near FM-S interface at low spin polarization of the current. We show that this effect c…
We present numerical and analytical studies of coupled nonlinear Maxwell and thermal diffusion equations which describe nonisothermal dendritic flux penetration in superconducting films. We show that spontaneous branching of propagating flux filaments occurs due to nonlocal magnetic flux diffusion and positive feedbac…
With a study of bulk GaAs and GaP, we report detailed infrared spectra and their temperature dependence from first principles. Fine features and low-temperature trends in the predicted response are confirmed by experiment. The spectra are calculated from the far-infrared through twice the frequency of the zone-center…
The effect of disorder on the critical properties of the ferromagnetic phase transition in colossal magnetoresistive manganite La0.67Ca0.33MnO3 has been studied by substituting Ga for Mn. It is found that, upon 10% Ga substitution, the peak in the specific heat at the Curie point T_C changes drastically and appears as…
We use considerations of energy balance and dissipation to derive a self-consistent version of the shear-transformation-zone (STZ) theory of plastic deformation in amorphous solids. The theory is generalized to include arbitrary spatial orientations of STZs. Continuum equations for elasto-plastic material and their en…
The first instance of a remarkable enhancement in toughness and stiffness of a poly(vinylidene fluoride) nanocomposite compared to the pristine polymer is reported (see Figure). The enhanced toughness is attributed to structural and morphological changes induced by the nanoparticles, as well as their increased mobilit…
Compact, solid-state UV emitters have many potential applications, and ZnO-based materials are ideal for the wavelength range 390 nm and lower. However, the most efficient solid-state emitters are p–n junctions, and p-type ZnO is difficult to make. Thus, the future of ZnO light emitters depends on either producing low…
Abstract Electrospinning provides a simple and versatile method for generating ultrathin fibers from a rich variety of materials that include polymers, composites, and ceramics. This article presents an overview of this technique, with focus on progress achieved in the last three years. After a brief description of th…
By coupling 5-bromo-(chloro)-7-formyl-8-hydroxyquinoline with 2-methylene-1,3,3-trimethylindoline, the 6'-halogeno-spiro[indoline-2,2'-[3,2-h]-pyrido[2H-1]benzopyrans] 3 have been prepared and their photochromic behaviors studied.The photoinduced merocyanine forms 4 of the spiropyrans form fluorescent complexes with d…
Synchrotron radiation beamlines offer automated data collection with faster and larger detectors, a choice of wavelength(s), intense beams and fine collimation. An increasing output of protein crystal structures sustains an interest in streamlining data collection protocols. Thus, more and more investigators are looki…
Since lead titanate was first grown in single-crystal form in the 1930s, several independent reports of its linear birefringence have been published. Whilst there is overall qualitative agreement on its behaviour with temperature, the absolute values show some degree of variation. At 298 K they range from −0.009 to −0…
The photophysical and photochemical properties of a cationic porphyrin [bis(arginyl)porphyrin (BAP)] complexed to [poly(dG-dC)] 2 and [poly(dA-dT)] 2 have been investigated and compared to those of free BAP in aqueous solution. A drastic enhancement of the quantum yield of nonradiative deactivation of the lowest excit…
The conversion of the spin state of complexes exhibiting thermal spin crossover from the 1 A 1 low-spin (LS) state to the 5 T 2 high-spin (HS) state is accompanied by a deformation of the lattice due to the larger bond lengths in the HS state as compared with the LS state. In a previous work [Kusz et al. (2000). J. Ap…
The program CRYSTALS [Betteridge, Carruthers, Cooper, Prout & Watkin (2003). J. Appl. Cryst. 36 , 1487] has been extended to include an option for the refinement of a continuous electron density distribution lying along a line, a ring or on the surface of a sphere. These additional non-atomic electron distribution…