Materials Literature
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A series of codoped nanocrystalline ceria compositions, Ce 1 - x M x Bi 0.4 O 2.6 - x (M = Ca, Sr, and Ba; x = 0.01−0.15) were hydrothermally synthesized at 240 °C and characterized by powder X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. All as-made Ce 1 - x M x Bi 0.4…
Two novel, isostructural, one-dimensional tellurites of molybdenum(VI), (NH 4 ) 4 Mo 6 TeO 22 ·2H 2 O and Rb 4 Mo 6 TeO 22 ·2H 2 O, have been synthesized by hydrothermal method. They contain linear (Mo 6 TeO 22 ) 4 - anionic chains, parallel to one another and held together by NH 4 + /Rb + ions. “Mo 6 O 22 ” moieties,…
In this paper, the nonlinear dynamics of a new Shape Memory Alloy (SMA) actuator that possesses impressive payload lifting capabilities are presented. This actuator consists of 48 SMA wires mechanically bundled in parallel forming one powerful muscle. It was designed to lift up to 45.4 kg (100 lbs), which is approxima…
Complex formation between small carboxyl-terminated dendritic polymers and oppositely charged poly(dimethyldiallylammonium chloride) was monitored by turbidimetry, dynamic light scattering, viscometry and potentiometric titration. All techniques reveal a discontinuity at a well-defined pH, corresponding to the point o…
We have used neutron reflection to study the effects of pH and added electrolyte on the structure of a weak polyelectrolyte brush anchored by means of a hydrophobic block to a hydrophobic surface. The copolymer was poly(2-(dimethylamino)ethyl methacrylate- block -methyl methacrylate) (poly(DMAEMA- b -MMA)) containing…
The oxidation of various para-substituted phenyl methyl sulfoxides with several substituted oxo(salen)manganese(V) complexes follows an overall second-order kinetics that is first-order in sulfoxide and in oxo(salen)manganese(V) complex. Electron-releasing substituents in sulfoxides and electron-withdrawing substituen…
Orange-red crystals of [Pt(CN)2(bpy)] (bpy = 2,2‘-bipyridine) and [Pt(CN)2(i-biq)] (i-biq = 3,3‘-biisoquinoline) show completely different temperature-dependence of emission behavior which has been explained in terms of the characteristic change of each crystal structure based on the platinum−platinum and ligand π−π i…
Using a tridentate bis-amide ligand 2,6-bis[ N -(phenyl)carbamoyl]pyridine (H 2 L), in its deprotonated form, nickel complexes in three consecutive oxidation states [Et 4 N] 2 [Ni II L 2 ]·H 2 O ( 1 ), [Et 4 N][Ni III L 2 ]·H 2 O ( 2 ), and [Ni IV L 2 ]·0.75H 2 O ( 3 ) have been prepared, and 1 and 3 structurally char…
Hybrid SiO 2 −B 2 O 3 gels have been synthesized from cohydrolysis of modified silicon alkoxides (R−Si(OE) 3 R = Me, Vi, Et) and triethylborate, B(OEt) 3 . The structure of these gels was investigated by Fourier-transformed infrared (FT-IR) spectroscopy, 29 Si and 11 B solid-state nuclear magnetic resonance (NMR), X-r…
We present a theoretical study of the role of the local environment in the electronic properties of carbon nanotubes: isolated single- and multi-wall nanotubes, nanotube-ropes, tubes supported on gold and cutted to finite length. Interaction with the substrate or with other tubes does not alter the scanning-tunneling-…
We show that the current carrier density collapse in doped manganites, which results from bipolaron formation in the paramagnetic phase, leads to a colossal change of the optical conductivity in an external magnetic field at temperatures close to the ferromagnetic transition. As with the colossal magnetoresistance (CM…
In this paper we measure the optical extinction spectrum of a periodic array of silver nanoparticles fabricated by nanosphere lithography (NSL) and present detailed comparisons of the results with predictions of electrodynamic theory. The silver nanoparticles are small (∼100 nm) compared to the wavelength of light but…
The transport and relaxation dynamics of singlet excitons of rodlike [tetramethoxytetrakis(octyloxy)phthalocyaninato]polysiloxane (PcPSi) in tetrahydrofuran solution were investigated on the femtosecond scale by transient absorption spectroscopy. Singlet excitons are generated upon excitation into the ground-state abs…
Reaction of the tripodal ligands tris(N-alkylbenzimidazol-2-ylmethyl)amine with europium perchlorate affords the luminescent complexes [Eu(Rntb)2](ClO4)3·nCH3CN·0.5H2O (R = methyl, npropyl; n = 1, 2) in which the central Eu3+ ion is well encapsulated in a cubic coordination environment. Right- or left-handed screw arr…
Graphite nanofibers are a newly developed type of material produced by the catalytic decomposition of carbon containing gases at high temperatures. The individual components of these conformations, small-sized graphite crystallites, are arranged in such a manner that only the edge regions are exposed. The carbon atoms…
Liquid crystals based upon bent-rod mesogens are of interest for the design of novel polar and/or biaxial phases. This study reports bent-rod mesogens containing a variable lateral dipole moment and the stability of their phases. X-ray crystallography suggests that the bent-rod and lateral dipoles produce antiparallel…
The adsorption of CO on Au thin film electrodes vacuum-deposited on silicon substrate has been studied in 0.1 M perchloric acid solution by surface-enhanced infrared absorption spectroscopy (SEIRAS) with the Kretschmann attenuated-total-reflection configuration. Scanning tunneling microscopy (STM) was used to investig…
Approximating the shape of the measured in $Bi_2Sr_2CaCu_2O_y$ magneto-thermopower (TEP) $ΔS(T,H)$ by asymmetric linear triangle of the form $ΔS(T,H)\simeq S_p(H)\pm B^{\pm}(H)(T_c-T)$ with positive $B ^{-}(H)$ and $B ^{+}(H)$ defined below and above $T_c$, we observe that $B ^{+}(H)\simeq 2B ^{-}(H)$. In order to acc…
Local density functional results are presented for the electron-doped metallochloronitrides A(x)ZrNCl and A(x)HfNCl, A = Li or Na, which superconduct up to 25K. The alkali non-stoichiometry is treated in a virtual crystal approximation. The electronic structure is strongly two dimensional, especially in the conduction…
We comment on a recent article by H. L. Neal [Am. J. Phys. 66, 512 (1998)], in which an analytic expression for the Hohenberg-Kohn functional was derived for one-dimensional two-particle systems with the harmonic interaction. We argue that the functional given by Neal is not exact but really constitutes an approximati…