Materials Literature
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A systematic study of hysteresis in model continuum and lattice spin systems is undertaken by constructing a statistical-mechanical theory wherein spatial fluctuations of the order parameter are incorporated. The theory is used to study the shapes and areas of the hysteresis loops as functions of the amplitude (${\mat…
Abstract Organic acids can form stable complexes with metals and therefore can affect metal solubility and speciation. The low‐molecular‐weight aliphatic organic acids extracted in water and present in soil solution from O, A, Bh and Bt horizons from a group of forested Utlisols, Entisols and Spodosols were identified…
Abstract We present chain structure, phase morphology, and toughness relationships in thermoplastic polymers and polymer/rubber blends. In neat polymers, molecular aspects of craze/yield behavior are controlled by two chain parameters: entanglement density ν e and characteristic ratio C ∞ . The crazing stress is propo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA new ambient-pressure organic superconductor, .kappa.-(ET)2Cu[N(CN)2]Br, with the highest transition temperature yet observed (inductive onset Tc = 11.6 K, resistive onset = 12.5 K)Aravinda M. Kini, Urs Geiser, Hau H. Wang, K. Douglas Carlson, Jack M. Williams, W. K. Kwok,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTActivation hardness: new index for describing the orientation of electrophilic aromatic substitutionZhongxiang Zhou and Robert G. ParrCite this: J. Am. Chem. Soc. 1990, 112, 15, 5720–5724Publication Date (Print):July 1, 1990Publication History Published online1 May 2002Publi…
This paper deals with the application of ZnO varistors—an area which has not been treated in a systematic way in the literature. The paper starts with a brief description of the fundamental properties comprising the electrical behavior as well as the physics, chemistry, and microstructure of the varistor. These proper…
Experimental observation of the nonadditivity of various mechanisms of population inversion of the 4I11/2→4I13/2 transition of the Er3+ ion in a YSGG:Cr3+:Er3+ crystal, M A Noginov, G K Sarkisyan, Valerii A Smirnov, A F Umyskov, Ivan A Shcherbakov
A compact desk reference, this book includes all the subjects contained in the 17 alphabetical volumes and the Supplement and Index volumes of the Encyclopedia of Polymer Science and Engineering. The articles have been condensed by professional science writers, reviewed for accuracy by the original authors or their co…
This graduate textbook presents a concrete and up-to-date introduction to the theory of Coxeter groups. The book is self-contained, making it suitable either for courses and seminars or for self-study. The first part is devoted to establishing concrete examples. Finite reflection groups acting on Euclidean spaces are…
The optical absorption and electron spin resonance spectra of vanadyl-and copper-doped rubidium cadmium sulphate hexahydrate are investigated at room and liquid nitrogen temperatures. From the analysis, the spectra are ascribed C 4v site symmetry in the case of VO 2+ ions and D 2h site symmetry in the case of Cu 2+ io…
Solid solutions of (KI${)}_{1\mathrm{\ensuremath{-}}\mathit{x}}$(${\mathrm{NH}}_{4}$I${)}_{\mathit{x}}$ with concentrations x=0.14, 0.43, and 1 were investigated using dielectric spectroscopy. The high-temperature rocksalt structure of these compounds exhibits a dipole moment of 1.4 D. For x=0.14 and 0.43 the NaCl str…
The magneto-optical polar Kerr effect has been measured on CuCr2Se4 single crystals between 0.55 and 5.0 eV. The single Kerr ellipticity εK reaches −1.19° at 0.96 eV which is (besides PtMnSb with θK=−1.27° at 1.72 eV) the highest value ever observed at room temperature. The figure of merit R1/2(θ2K + ε2K)1/2 has a max…
The temperature dependence of the infrared-active internal modes of NaNO 3 has been investigated between 77 K and 700 K. The structural phase transition at 549 K is observed through the appearance of additional peaks subsidiary to the expected nitrate group internal modes. In particular, an extra peak is observed at s…
The authors present novel real-space renormalization results for a lattice model of the collapse (coil-globule) transition of a polymer molecule adsorbing to a wall. These results support the conjecture that adsorption stabilises the collapsed phase by enhancing the collapse transition temperature. The analysis is dev…
A molecular-dynamics simulation is carried out to study the changes in statistical geometry and related dynamical properties in the Li2SiO3 system at the glass transition point. The number of oxygens around each cation within the first coordination shell is taken as the number V of vertices of the polyhedron that char…
The complete nucleotide sequence of the Clostridium thermoaceticum formyltetrahydrofolate synthetase (FTHFS) was determined and the primary structure of the protein predicted. The gene was 1680 nucleotides long, encoding a protein of 559 amino acid residues with a calculated subunit molecular weight of 59,983. The ini…
High-speed laser direct writing of tungsten conductors using tungsten-hexacarbonyl [W(CO)6] is demonstrated. Tungsten lines were constructed on the Si-LSI substrate at a writing speed as high as 300 μm/s with laser-induced low-pressure chemical vapor deposition. This speed is more than two orders of magnitude higher t…
The response of a growing crystalline dendrite to a brief localized heat pulse applied near its tip was investigated in a directional solidification experiment on succinonitrile containing 1% acetone. The induced deformation was initially unobservably small, but grew rapidly into a sidebranchlike feature with time. Th…
The authors present a comparative study of the properties of two solution-processible alkyl-substituted polythienylenes, poly(3-hexyl thienylene), P3HT and poly(3-dodecyl thienylene), P3DT. Both show the onset of pi - pi * interband absorption at 2 eV with the peak in absorption coefficient near 2.5 eV, and both show…
The first measurements are reported for the AC conductivity (real and imaginary parts) of the semiconducting CuO-Bi 2 O 3 -P 2 O 5 glasses in the frequency range 10 2 -10 5 Hz and in the temperature range 80-4000 K. The experimental results have been analysed in the light of various theoretical models proposed for amo…