Materials Literature
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To elucidate the dynamics and mechanisms of radiationless transitions from higher excited electronic states as well as the ultrafast intramolecular vibronic relaxation in porphyrin derivatives, we have studied the fluorescence dynamics of Zn-tetraphenylporphyrin (ZnTPP) and Zn-diphenylporphyrin derivatives (ZnDPP) in…
It has been discovered that kinetics of structural changes in Pd and Pd-alloys under the influence of dissolved hydrogen seems to be non-trivial. As a rule, structural changes in these systems include correlation changes of co-existing phases concentration and the defect structure character. These changes have the sta…
Wide band-gap semiconductor zinc oxide nanoclusters have been prepared in the channels of MCM-41 materials by functionalizing the MCM-41 with ethylenediamine groups, absorbing zinc cations, and calcinating at high temperatures. The products have been characterized by XRD, TEM, EDS, nitrogen adsorption and desorption,…
Emerging electrosynthetic techniques such as electrogeneration of base, anodic oxidation, and ac (alternating current) synthesis provide simple and inexpensive alternative routes to the synthesis of ceramic thin films and coatings, nanoparticulate materials, and metastable phases. In this review, we survey illustrativ…
Abstract Iron sulfide scale deposition occurs throughout the Kaybob South field in Central Alberta. The scale typically forms directly on the tubular walls and generally results in corrosion of the metal beneath the scale crystallites. Under normal conditions, iron sulfide is soluble in hydrochloric acid. However, in…
A very reliable and reproducible electrochemical preparative procedure to obtain oxygen-sensitive lithium phthalocyanine (LiPc) microcrystalline powder, a critical material for in vivo application of electron paramagnetic resonance (EPR) oximetry to measure the partial pressure of molecular oxygen p O 2, is described.…
Aging of power plants and competitive pressures to operate and maintain (O&M) these plants at reduced costs have heightened industry interest in life assessment and management technologies. Piping and tubing systems carrying high-pressure steam at temperatures exceeding 1000°F (530°C) have notably been the center…
The dispersity, size, and self-interaction of generation 5 polyamidoamine dendrimeric polymers with different terminal groups (surfaces) were characterized using several physicochemical techniques. Amino-surface dendrimers form oligomeric aggregates in aqueous solution, even in the presence of high salt concentrations…
The molecular organisation of protein aggregates, formed under physiological conditions, has been explored by in vitro trypsin treatment and electron microscopy analysis of bacterially produced inclusion bodies (IBs). The kinetic modelling of protein digestion has revealed variable proteolysis rates during protease ex…
We extend the recently proposed order-N algorithms (cond-mat/9703224) for calculating linear- and nonlinear-response functions in time domain to the systems described by nonorthonormal basis sets.
Despite a large amount of data and numerous theoretical proposals, the microscopic mechanism of transport in thick film resistors remains unclear. However, recent low temperature measurements point toward a possible variable range hopping mechanism of transport. Here we examine how such a mechanism affects the gauge f…
The synthesis of nickel nanoparticles by the reduction of nickel chloride with hydrazine in the cationic water-in-oil microemulsions of water/CTAB (cetyltrimethylammonium bromide)/ n -hexanol at 73 °C has been studied. By the analyses of electron diffraction pattern and X-ray diffraction, the resultant particles were…
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…
Electron beam, thermal free radical, and cationic complexation mechanisms have been employed to investigate crosslinking in selected polyphosphazenes. In polyphosphazenes functionalized with o-allylphenol to facilitate free radical crosslinking, maximum crosslink density was achieved after 10 min at 130°C utilizing be…
We report the structural, magnetic and electron transport properties of a new series of compounds where we have substituted Al 3+ in the Mn site of rhombohedral, cation deficient LaMnO 3+ . All the samples crystallize in rhombohedral ( R c ) symmetry with minimal changes in lattice parameters. Mn 4+ content gradually…
Thermally stimulated creep recovery (TSCR) experiments have been used to study the influence of tacticity on the α retardation process in amorphous poly(methyl methacrylate) (PMMA). The α retardation process associated with the glass transition is strongly dependent on tacticity. The high-sensitivity TSCR−fractional l…
Laser-ablated iron, cobalt, and nickel atoms, cations, and electrons have been reacted with NO molecules during condensation in excess neon and argon. The end-on bonded Fe(NO) 1 - 3, Co(NO) 1 - 3, and Ni(NO) 1 - 2 nitrosyls and side-bonded Fe−(η 2 -NO), Co−(η 2 -NO), and Ni−(η 2 -NO) species are formed during sample d…
The nature of the superionic transition in Ag2 HgI4 and Cu2 HgI4 has been investigated using temper dependent powder neutron diffraction and impedance spectroscopy techniques. In the case of Ag2 HgI4 , the superionic transition occurs at Tc = 326(2) K and is accompanied by a 50-fold increase in the ionic conductivity.…
The Gibbs canonical distribution, d w ~ exp ( - E ( p , q ) / k B T ) d p d q , seems one of the most solid pillars of statistical physics. Thermodynamics is believed to be a derivative of this distribution. Since the temperature T is introduced, de facto , from a heat bath by the zeroth law of thermodynamics, this di…
The reaction kinetics over a V 2 O 5 −WO 3 /TiO 2 catalyst which can describe the NH 3 slip from a selective catalytic reduction (SCR) reactor as well as the maximum conversion of NO over a wide range of reaction temperatures was developed to design the SCR process. The modeling of the reactor based upon the kinetics…