Materials Literature
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We propose here a new mechanism of droplet coarsening in phase-separating fluid mixtures. In contrast to the conventional understanding that there are no interactions between droplets in the late stage of spinodal decomposition, we demonstrate the existence of interactions between droplets that is caused by the coupli…
In an attempt to unravel the role of conserved histidine residues in the structure-function of sheep liver cytosolic serine hydroxymethyltransferase (SHMT), three site-specific mutants (H134N, H147N, and H150N) were constructed and expressed. H134N and H147N SHMTs had Km values for L-serine, L-allo-threonine and beta-…
Abstract— We present results from an ongoing study of the infrared (IR) and optical properties of nanodiamonds, an objective of which is to identify spectral features in the laboratory that could also be used telescopically to trace the presence of these particles in the interstellar medium (ISM). Fourier transform mi…
The Young modulus for crystalline polyethylene is calculated using ab initio molecular dynamics based on density functional theory in the local density approximation (DFT-LDA). This modulus, which can be seen as the ultimate value for the Young modulus of polyethylene fibers, is found to be 334 GPa. For the first time…
Porphyrins and metalloporphyrins can be readily functionalized at the meso-(5,10,15,20)-positions by using a variety of reagents, the Vilsmeier formylation reaction being universally regarded as the prototypical example. On the other hand, the literature shows that corroles and metallocorroles are unusually resistant…
The electrochemical etching of n-type GaAs in HF solutions in the dark results in the formation of a porous layer. The pore density, the pore dimensions and the structure of the porous layer depend on the doping density and the crystallographic orientation of the surface. The pore morphology of porous GaAs is essentia…
The effects of complexed metal ions on trans − cis photoisomerization reactions of two azobenzene compounds having a crown ether ring, 1a (small ring) and 1b (large ring) were investigated. The photoisomerization of 2,2‘-dimethoxyazobenzene ( 2 ) was compared as a control. Anomalous increase in the quantum yields of t…
The microscopic dynamics of several monomeric and polymeric glass-forming materials has been investigated by time-resolved fluorescence measurements of doped malachite green molecules in a wide temperature region. For monomers, 1-propanol, propylene glycol, and glycerol, and a polymer without side chains, poly- butadi…
Variation with time of the chemically active three‐phase boundary, due to the spontaneous sintering of metal particles, is simulated with the help of a correlated percolation model. Different modes of variation are obtained depending on the relative composition and porosity and the conditions of sintering. They range…
The longitudinal electromechanical coupling factor ( k 33 ) was investigated as a function of PbNi 1/3 Nb 2/3 O 3 – PbTiO 3 –PbZrO 3 (PNN-PT-PZ) piezoelectric ceramic compositions close to the morphotropic phase boundary (MPB). The k 33 was influenced by the grain size of PNN-PT-PZ ceramics. The composition of the MPB…
Abstract 21 new organometallic complexes of the type M–Cn–M′ containing the building blocks M, M′ = (CO) 5 Cr, (CO) 5 Mo, (CO) 5 W, Cp(CO) 2 Mn, Cp(CO) 2 Fe, Cp(CO)(CN)Fe, Cp(dppe)Fe, Cp(PPh 3 ) 2 Ru, Cp(PPh 3 )Ni, and (PPh 3 ) 2 Ag were obtained from the reagents M–Cn and M–X (X = leaving group). Among them are five…
All articles of this category An approach for synthesis of 4- tert -butylcalix[4]arenes bearing two Schiff base units at the lower rim 4a-u in excellent yields is described. All 21 compounds 4a-u have been achieved by treatment of 1,3-distally substituent 4- tert -butylcalix[4]arene amine 3 with aromatic or heterocycl…
Abstract The catalytic isomerization reaction of α‐pinene to camphene over a clinoptilolite catalyst was investigated in a batch reactor open to the atmosphere between 130 and 155°C. The catalyst was selective to the isomerization of α‐pinene to camphene. The effects of several variables, such as reaction temperature,…
A study has been made of the density profile of mutually avoiding rod-like particles in the space between two parallel plates, held in equilibrium with a bulk phase of isotropic, semidilute rods, using a self-consistent integral equation which becomes exact as the rod aspect radio L/D → ∞. Computer simulation investig…
With a high-refractive-index mixed-oxide dielectric material of ZrTiO(4) and ZrO(2) [Substance H2 (Sub2) from E. Merck, Darmstadt, Germany], in combination with magnesium flouride (MgF(2)), design optimization and experimental production of low-loss antireflection (AR) coatings are carried out. Design-optimization stu…
The crystal structures of heat‐treated electrolytic manganese dioxide (HEMD) and the discharge products are characterized by high‐spatial‐resolution convergent‐beam electron diffraction (CBED) and lattice imaging. In this paper, CBED results are used to clarify the ambiguity in the x‐ray diffraction (XRD) patterns of…
For the purpose of increasing the hydrophilicity of a polylactide, a new monomer, (3 S )-3-[(benzyloxycarbonyl)methyl]morpholine-2,5-dione, was successfully polymerized. The benzyl protective group of the polymer was completely removed to give poly(glycolic acid- alt - l -aspartic acid). The structures and properties…
Stannous‐lead phosphorus oxynitride (Sn‐Pb‐P‐O‐N) glasses were prepared by remelting under an anhydrous ammonia atmosphere. Glasses that contained up to ∼4.2 wt% (9 at.%) of nitrogen were obtained. The rate of nitrogen dissolution was studied as a function of remelting time (3–66 h) and temperature (400°–600°C). The o…
Abstract A modified CaCO 3 sorbent with an open internal pore structure is prepared and its sulfation characteristics are investigated in an entrained flow reactor at high temperatures (900‐1,100°C) and short contact times (20–600 ms) using small particle sizes (< 5 μm). The most distinguishing feature of this modi…
The functional role of previously identified calcium binding residues in alpha-lactalbumin (alpha-LA) was investigated by site-directed mutagenesis. Mutation of D82 to alanine did not effect the binding affinity for calcium, the protein structure, or its function in the lactose synthase assay, suggesting that this asp…