Materials Literature
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Abstract Recycling PET from bottles has been carried out by three different extrusion methods. Under optimized processing conditions, a virgin poly(ethylene terephthalate (PET), recycled PET and a mixture of virgin and recycled PET, with and without the modifier polypropylene functionalized with maleic anhydride [PP‐…
The influence of the cross-linking degree on the dynamics of the segmental motions close to the glass transition of poly(methyl methacrylate), PMMA, networks was investigated by three different mechanical spectroscopy techniques: thermally stimulated recovery (TSR), dynamic mechanical analysis (DMA), and creep. The ap…
The ab initio tensile test has been applied to an Al \ensuremath{\Sigma}9 grain boundary by using the ab initio pseudopotential method. The theoretical tensile strength is 9.50 GPa at the strain 21%. As compared with the theoretical tensile strength in the direction [001] or [111] of an Al single crystal, the boundary…
Abstract Lignocellulosic fractions from wheat straw were used as natural fillers in composites of a polyolefin (a copolymer of polyethylene and polypropylene) and a biodegradable polyester [poly(butylene adipate‐ co ‐terephthalate)]. The mechanical properties of these injected composites were investigated with tensile…
Using time-resolved and continuous wave (cw) photoluminescence (PL) spectroscopy of Si nanocrystals embedded in ${\mathrm{SiO}}_{2}$ with varying content of the nanocrystalline silicon phase, we were able to distinguish between microscopic characteristics of the PL decay that are associated with quantum confinement ef…
We investigate transport through 6 to 10 nm thin epitaxial GaAs(001) barriers sandwiched between polycrystalline iron films. Apart from a pronounced tunneling magnetoresistance effect (TMR) at low magnetic fields we observe a distinct negative magnetoresistance (MR) at low and a positive MR at higher temperatures. We…
A mixed II-VI semiconductor Zn[1-x]Be[x]Se possesses non-trivial vibration properties, because its two constituent compounds, ZnSe and BeSe, show very different degree of covalency and hence high elastic contrast. An anomalous Be-Se vibration line has been observed mostly at intermediate Be content in the Raman spectr…
The Glauber dynamics is studied in a single-chain magnet. As predicted, a single relaxation mode of the magnetization is found. Above 2.7 K, the thermally activated relaxation time is mainly governed by the effect of magnetic correlations and the energy barrier experienced by each magnetic unit. This result is in perf…
The ability of the ESEM to condense and evaporate liquids has enabled the in situ dynamic study of condensation, evaporation and transport of water inside carbon nanotubes. It has been possible to see liquid menisci inside straight, CVD-fabricated carbon nanotubes (CNTs) having disordered walls. From the measured cont…
Carbon nanotube scrolls (CNSs) provide an interesting form of carbon that ideally consists of a single sheet of graphite that is spiral wrapped to form a nanotube. We here use molecular dynamics simulations to investigate CNS formation, stability, and the structural effects due to charge injection. CNS formation is se…
Based on first-principles calculations, a model for large-size-mismatched group-V dopants in ZnO is proposed. The dopants do not occupy the O sites as is widely perceived, but rather the Zn sites: each forms a complex with two spontaneously induced Zn vacancies in a process that involves fivefold As coordination. More…
We study the potential distribution, depletion length, and capacitance–voltage characteristics of two-dimensional (2D) linearly graded p–n junctions. It is shown that the total-depletion length is proportional to the square root of the contact potential difference, in contrast to the linear dependence for an abrupt 2D…
The 82-residue hypothetical protein NMA1147 (SwissProt/TrEMBL ID Q9JR91) encoded in the genome of Neisseria meningitidis is a member of a target sequence cluster1 of the Northeast Structural Genomics Consortium (NESGC; http://www.nesg.org; NESGC cluster ID 15365) that comprises both eukaryotic and bacterial members. T…
Gold nanoclusters dispersed in single-crystal SrTiO3 (STO) (001) have been prepared by ion implantation at both 300 and 975 K followed by annealing at 1275 K for 10 h. High-resolution transmission electron microscopy (TEM), high-angle annular dark-field imaging in an aberration-corrected dedicated scanning TEM, and im…
Fluidized catalyst beds have been used in chemical and refinery processes and studied extensively for more than 50 years. However, the features of this reactor are still not understood perfectly. There is still much more to learn about the fluidized catalyst beds. It is important to elucidate the bubble behavior and t…
A genetic algorithm (GA)-based procedure for finding the global minimum of medium-sized Si x H y clusters at the ab initio level is presented. Semiempirical calculations are used to prescreen the relative energies of the many locally optimized Si x H y structures generated by the GA. The AM1 semiempirical method used…
A systematic study of photoluminescence (PL) behavior of Si nanocrystals in SiO2 obtained by ion implantation in a large range of temperatures (−200 up to 800 °C), and subsequent furnace annealing in N2 ambient was performed. A PL signal in the wavelength range 650–1000 nm was observed. The PL peak wavelength and inte…
Abstract Star styrene–isoprene–butadiene rubber (SIBR) was synthesized with a new kind of star anionic initiator made from naphthalene lithium and an SnCl 4 coupled agent. The relationship between the structure and properties of star SIBR was studied. Star block styrene–isoprene–butadiene rubber (SB‐SIBR), having low…
Thioacetylacetone and its variously deuterated isotopomers have been investigated using electronic and vibrational spectroscopy combined with quantum chemical calculations. Thioacetylacetone is known for its photochromic properties, but the structures of the initial and final forms have been the subject of a long deba…
We have investigated the microstructures of melt-spun Sm(Co0.58Fe0.31Cu0.04Zr0.05B0.02)z (z=7.5 and 12) ribbons by transmission electron microscopy (TEM) and three dimensional atom probe (3DAP) to correlate them with the hard magnetic properties. The ribbon with z=7.5 has a high coercivity (iHc∼12 kOe) while the ribbo…