Materials Literature
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We describe both experimentally and theoretically a hydrodynamic pumping mechanism in a Fermi liquid, arising from electron-electron interaction. An electron beam sweeping past an aperture is observed to pump carriers from this aperture. Experimentally, the pumping effect induces a current in the lead connected to the…
We investigate the operational characteristics of a nanorelay based on a conducting carbon nanotube placed on a terrace in a silicon substrate. The nanorelay is a three-terminal device that acts as a switch in the gigahertz regime. Potential applications include logic devices, memory elements, pulse generators, and cu…
In this paper, we present a microscopic model for heterogeneous ferroelectric and an order parameter for relaxor phase. We write a Landau theory based on this model and its application to ferroelectric PbFe$_{1/2}$Ta$_{1/2}$O$_3$ (PFT) and antiferroelectric NaNbO$_3$:Gd. We later discuss the coupling between soft mode…
Detection of the degree of circular polarization of the electroluminescence of a light-emitting diode fitted with a spin injecting contact (a spin-LED) allows for a direct determination of the spin polarization of the injected carriers. Here, we compare the detection efficiency of (Al,Ga)As spin-LEDs fitted with a (Zn…
The dynamics of homogeneous nucleation and growth of crystalline nickel from the super-cooled melt is examined during rapid quenching using molecular dynamics and a modified embedded atom method potential. The character of the critical nuclei of the crystallization transition is examined using common neighbor analysis…
A new LDA+U band calculation is performed on the Kondo insulator material YbB$_{12}$ and an energy gap of about 0.001Ryd is obtained. Based on this, a simple tight-binding model with 5d$ε$ and 4f $Γ_8$ orbitals on Yb atoms and the nearest neighbor $σ$-bonds between them is constructed with a good agreement to the abov…
Mesoporous silica was synthesised by sol–gel mineralisation using nematic liquid crystalline templates consisting of partially ordered suspensions of cellulose rod-like nanocrystals, ca. 145 × 13 nm in size. The nanorods were prepared by acid hydrolysis of cellulose powder and concentrated droplets evaporated onto gla…
Amorphous metallic alloys, also called metallic glasses, are of considerable technological importance. The metastability of these systems, which gives rise to various rearrangement processes at elevated temperatures, calls for an understanding of their diffusional behavior. From the fundamental point of view, these me…
Random lattice disorder produced by chemical substitution in ABO 3 perovskites can lead to the formation of dipolar impurities and defects that have a profound influence on the static and dynamic properties of these materials that are the prototypical soft ferroelectric (FE) mode systems. In these highly polarizable h…
Epitaxy of oxide materials on silicon (Si) substrates is of great interest for future functional devices using the large variety of physical properties of the oxides as ferroelectricity, ferromagnetism, or superconductivity. Recently, materials with high spin polarization of the charge carriers have become interesting…
Short peptides derived from p14ARF and Hdm2 (14 and 15 amino acids in length, respectively), two cancer associated proteins, have been found to co-assemble into amyloid-like structures. Larger protein domains containing these peptide segments interact in cells and also undergo a disorder-to-order transition upon bindi…
Heterophasic propylene−ethylene copolymers (HPEC) containing bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate (Tinuvin 770) as a hindered amine stabilizer (HAS) were thermally aged at 393 and 433 K. Two types of HPEC were examined, containing 25 and 10% ethylene (E), respectively, as ethylene/propylene rubber (EPR). Sp…
Although serine acetyltransferase (SAT) from Escherichia coli is homologous with a number of bacterial enzymes that catalyze O-acetyl transfer by a sequential (ternary complex) mechanism, it has been suggested, from experiments with the nearly identical enzyme from Salmonella typhimurium, that the reaction could proce…
[structure: see text] The synthesis of 1,4,5,8,9,12,13,16-octamethoxytetraphenylene (6) is accomplished in five steps from 3,6-dimethoxy-2-nitroaniline (8). Its inclusion property and the electrochemical data of the corresponding tetraquinone 7 are presented.
The synthesis and coordination chemistry of two porphyrin dimers linked either at the 5,5' or the 4,4' positions of 2,2'-bipyridine are described. These compounds, which may serve a molecular tectons for the constructions of a variety of supramolecular arrays of diverse function, reveal that the ground- and excited-st…
The Southeast Collaboratory for Structural Genomics consists of four working groups. The protein production group supplies/develops high-output production of Pyrococcus furiosus, Caenorhabditis elegans, and selected human proteins. The X-ray crystallography group conducts high-throughput structure production in parall…
The tautomeric, vibrational, and H-bonding characteristics of N4-methoxycytosine (N4MC) are investigated by a combined experimental, matrix-isolation Fourier transform infrared spectroscopic and computational study. For the theoretical part of the study, the methods RHF, MP2, and DFT(B3LYP) are used with the 6-31++G**…
A kind of carbon nanotube bundle has been synthesized by a simple one-step solvothermal reaction between Na and hexachlorobenzene (HCB) using NiCl 2 as catalyst precursor. Before the reaction, NiCl 2 was initially dispersed ultrasonically in cyclohexane then prereduced by Na at 230 °C to produce small Ni particles in…
The miscibility of metallocene linear low-density polyethylene (m-LLDPE) and Ziegler−Natta LLDPE (ZN-LLDPE) with linear high-density polyethylene (HDPE) was studied. The influences of composition distribution (CD) and branch content (BC) on the miscibility of m-LLDPE and ZN-LLDPE with HDPE were investigated with rheol…
In this study, an achiral liquid-crystalline azo polymer is irradiated with circularly polarized light, and the transmitted polarization data show evidence of photoinduced chirality. When the polarization of the laser is switched from left- to right-handed, the chirality of the polymer film is switched as well. In a m…