Materials Literature
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We studied the magnetic anisotropy of two molecular magnets, ${\mathrm{Fe}}_{6}$ and ${\mathrm{Fe}}_{10},$ which comprise six- and ten-membered rings of antiferromagnetically coupled iron (III) ions ${(S}_{i}=\frac{5}{2}),$ respectively. Spin-flip transitions induced by the applied magnetic field (up to 23 T) were inv…
In low‐pressure environments, precipitation of graphite is hindered at low to moderate temperatures by the high solubility of carbon in C‐O‐H fluids and by kinetic barriers to nucleation. Those low‐temperature fluids that do attain saturation tend to precipitate graphite continuously during flow and cooling, thereby p…
The effects of Ga doping on Mn site in the colossal magnetoresistance material ${\mathrm{La}}_{0.67}{\mathrm{Ca}}_{0.33}{\mathrm{MnO}}_{3}$ have been studied by preparing the series ${\mathrm{La}}_{0.67}{\mathrm{Ca}}_{0.33}{\mathrm{Mn}}_{1\ensuremath{-}x}{\mathrm{Ga}}_{x}{\mathrm{O}}_{3}$ $(x=0.0,0.02,0.05,0.1).$ Upon…
The length-scale dependence of the dynamic entropy is studied in a molecular dynamics simulation of a binary Lennard-Jones liquid above the mode-coupling critical temperature T(c). A number of methods exist for estimating the entropy of dynamical systems, and we utilize an approximation based on calculating the mean f…
The complex conductivities between 10 mHz and 1 MHz of a series of disordered carbon-black-polymer composites have been measured. The carbon black volume fractions span the percolation threshold, with dc conductivities ranging from ${10}^{\ensuremath{-}18}$ to ${10}^{\ensuremath{-}6}(\ensuremath{\Omega}\mathrm{cm}{)}^…
The role of surface nitrogen in the kinetics of the NO+CO conversion reaction on Rh(111) under steady-state catalytic conditions was explored by using collimated molecular beams and mass spectrometry detection. Two types of kinetically different nitrogen atoms were identified on the surface. The buildup of a critical…
Low temperature plasma treatments of wool modify only the cuticle surface of the fibers, improving their surface wettability, dyeability, fiber cohesion, and shrink resistance. The shrink-resist properties obtained with plasma treatment do not impart a machine-washable finish, which is an important end-user demand. Ho…
A novel neutral nickel complex molecule with the extended TTF dithiolato ligand, propylenedithiotetrathiafulvalenedithiolate [ptdt 2- = (S 8 C 9 H 6 ) 2- ], was synthesized. In the [Ni(ptdt) 2 ] crystal. [Ni(ptdt) 2 ] molecules form one-dimensional columns along the a axis, having short intermolecular transverse S···S…
Delta(5)-3-Ketosteroid isomerase from Pseudomonas testosteroni has been intensively studied as a prototype to understand an enzyme-catalyzed allylic isomerization. Asp(38) (pK(a) approximately 4.7) was identified as the general base abstracting the steroid C4beta proton (pK(a) approximately 12.7) to form a dienolate i…
Dynamic and static light scattering is applied to concentrated suspensions of silica nanoparticles with surface functionalizations causing highly charged or hard sphere interaction potentials, respectively. The index of refraction of the dispersion medium was matched to that of the particles using a mixture of water/g…
Abstract Phenol-formaldehyde polymers and surfactant assembly was structuralized into lamella and disordered mesophases depending on the surfactant/phenol molar ratio at the synthesis.
The syntheses and characterization of two new 1,5-dimethyl-6-oxoverdazyl radicals bearing 2-pyridine and 4,6-dimethyl-2-pyrimidine rings as substituents are described. The radical precursors, the corresponding 1,2,4,5-tetrazanes, were prepared by condensation of the bis(1-methylhydrazide) of carbonic acid with the app…
We have investigated mechanical properties of diamond-like carbon (DLC) thin films, particularly the internal compressive stress and ways to alleviate it. Foreign atoms such as copper, titanium, and silicon were incorporated into the DLC films during pulsed laser deposition. The chemical composition of the doped films…
Using atomic force microscopy (AFM), detailed information on the formation of the nuclei and the growth of the lamellae is obtained. This is the first experimental data that show the appearance and disappearance of embryos, as predicted by thermodynamics. In addition, it is shown that branching is initiated by seconda…
Eight-coordinate gadolinium(III) complexes involving four chelating nitronyl nitroxide ligands have been prepared. An antiferromagnetic Gd(III)−nitroxide coupling is characterized for the first time in these five-spin systems.
We present mode-coupling equations for the description of the slow dynamics observed in supercooled molecular liquids close to the glass transition. The mode-coupling theory (MCT) originally formulated to study the slow relaxation in simple atomic liquids, and then extended to the analysis of liquids composed by linea…
This comparative study addresses the influence of microstructural evolution on mechanical properties of porous alumina sintered with and without the application of uniaxial pressure. A complete set of data on Young's modulus, long‐crack fracture toughness, and fracture strength for two alumina powders as a function of…
Plane-wave pseudopotential calculations of total energies were performed for three ordered perovskite related supercells in each of the eight stoichiometries of ${A(B}_{1/3}{B}_{2/3}^{\ensuremath{'}}){\mathrm{O}}_{3};$ $A=\mathrm{P}\mathrm{b},\mathrm{}\mathrm{Ba},B=\mathrm{Z}\mathrm{n},\mathrm{}\mathrm{Mg}$ and, ${B}^…
Abstract A porphyrin henicosamer was designed, synthesized, and structurally characterized using scanning tunnelling microscopy.
An apparatus for deep-ultraviolet interferometric lithography is described, in which the interfering beams illuminate the substrate through a fused silica prism and a layer of index-matching liquid. The liquid-immersion technique was found to be compatible with a commercially available, chemically amplified photoresis…