Materials Literature
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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…
Phosphoglycerate mutase (PGAM) activity in promastigotes of the protozoan parasite Leishmania mexicana is found only in the cytosol. It corresponds to a cofactor-independent PGAM as it is not stimulated by 2,3-bisphosphoglycerate and is susceptible to EDTA and resistant to vanadate. We have cloned and sequenced the ge…
Au nanoparticles were deposited onto SiO2/Si by evaporation, after which x-ray photoelectron spectroscopy (XPS) indicated some interfacial interaction between the Au and the Si. The sample was then processed by KrF pulsed excimer laser radiation (248 nm) in air, at a fluence of ∼20 mJ/cm2. Following this laser irradia…
Nanocomposite thin films consisting of Co nanoparticles in a diamond-like carbon (DLC) matrix were synthesized by plasma-assisted magnetron sputtering using a discharge with different Ar/CH4 gas flow ratio and chamber pressure. The evolution of the Co nanostructures was studied by x-ray photoelectron spectroscopy and…
Why do proteins adopt the conformations that they do, and what determines their stabilities? While we have come to some understanding of the forces that underlie protein architecture, a precise, predictive, physicochemical explanation is still elusive. Two obstacles to addressing these questions are the unfathomable v…
The effects of an increasing small signal amplitude on the piezoelectric small-signal response and electrostriction of tetragonal Pb(Zrx, Ti1−x)O3 thin films are investigated. The piezoelectric small-signal coefficient d33, piezoelectric large signal-strain S, and electrostriction coefficient M33 are measured using a…
Hydrothermal synthesis is an attractive method for the deposition of ferroelectric thin films because it can realize a low processing temperature of 200 °C or less. In this study, micron-sized PbZr1−xTixO3 (PZT) single crystals and thin films were fabricated on a Ti substrate at 160 °C by hydrothermal synthesis. The f…
We evaluate different switching behaviors of lead zirconate titanate (PZT) thin film capacitors with two different geometries: one, a square 100×100 μm; the second, a ribbon (1.6 μm width but with approximately the same total area), as a function of temperature T, and applied electric field E. The ribbon capacitor sho…
Transport properties of a single multiwalled carbon nanotube (MWNT) have been investigated in vacuum at room temperature. The MWNTs show the large current carrying capacity at large bias due to the ballistic transport. The conductance for a single MWNT around zero bias is 0.4G0, and increases almost linearly with the…