Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical Vapor Deposition Methods for the Controlled Preparation of Supported Catalytic MaterialsPhilippe Serp, Philippe Kalck, and Roselyne FeurerView Author Information Laboratoire de Catalyse Chimie Fine et Polymères, Ecole Nationale Supérieure d'Ingénieurs en Arts Chimiq…
Femtosecond spectroscopic studies of zinc tetraphenylporphyrin (ZnTPP) in benzene and dichloromethane are reported, combining both fluorescence up-conversion and transient absorption measurements. The purpose is to investigate the initial electronic and vibrational relaxation of the S 1 and S 2 excited states, in a sy…
We propose coating spherical particles or droplets with anisotropic nanosized objects to allow micron-scale colloids to link or functionalize with a 4-fold valence, similar to the sp 3 hybridized chemical bonds associated with, e.g., carbon, silicon, and germanium. Candidates for such coatings include triblock copolym…
The adsorption of Ar on open-ended single-walled carbon nanotube bundles was studied. The amount of argon, which corresponds to the first coverage adsorbed on open-ended carbon nanotube bundles, was about 3 mmol/g. The isosteric heat of adsorption was obtained from the isothermal adsorption measurement in the low cove…
We investigated the coalescence of ultrathin carbon nanotubes (UTCNTs) using the tight-binding molecular dynamics simulation technique. We have found that two UTCNTs having the same or different chirality can coalesce without initially introducing atomic defects to enhance the reaction. The chiral index of the coalesc…
Ein Tetramer aus Dimeren: Ein sehr stabiles, kastenförmiges, cyclisches Tetramer (siehe Bild) wurde aus meso-Pyridyl-substituierten meso-meso-verknüpften Zink(II)-diporphyrinen erhalten, wobei die Porphyrineinheiten streng senkrecht zueinander orientiert sind.
This paper describes the onset of a new approach for the prediction of the nucleation rates of polymorphs crystallized from solution. The first step in the development of the new method is to come to an accurate prediction of the interfacial energy between the nucleus and solution, one of the key factors in the nuclea…
The thresholdless, hysteresis-free V-shape electro-optical switching in surface-stabilized ferroelectric liquid crystals, observed usually with a triangular voltage form, has been shown to be rather an apparent and not a real effect. Strictly speaking, it is observed only at one characteristic frequency f(i) and is ac…
We present the results of a simulation study of the effects of pressure on structural changes in silica glass. We observe structural relaxations in glass under pressure that involve large atomic displacements and are accompanied by breaking of the original bonds and forming of new ones. A large proportion of the new t…
An unexplored family of polyoxometalates has evolved through the synthesis and structural characterization of the first examples of MoV sulfite heteropolyanions. The dodecanuclear molybdenum(V) sulfite exhibits a unique structural motif among polyoxometalates (see picture; gray polyhedra represent MoVO6 octahedral uni…
The effects of impurities on driving-rate-dependent energy loss in ferromagnets are investigated by analyzing several well-defined models for magnetization reversal. The random-field Ising models are analyzed using a mean-field approximation and Monte Carlo simulation. The hysteresis loop area A is found to obey a uni…
We present a study of the optical properties of Tb 3+ -doped NaPO 3 –GdPO 4 -based glasses by means of optical absorption measurements performed at room temperature both before and after x-ray irradiation. A numerical decomposition of the absorption spectra is performed, and the possible nature of the defects responsi…
Ein atmendes Molekularsieb für kleine Alkohole: Durch Komplexierung des Keggin-artigen Polyoxometallats [α-SiW12O40]4− (rot) mit dem Makrokation [Cr3O(OOCH)6(H2O)3]+ (grün und weiß) wird der atmende Ionenkristall 1 synthetisiert. Die Gastmolekül-freie Phase 2 wird einfach durch Evakuierung der Wassermoleküle hergestel…
Riesenringe und Nanoscheren: Während sich Nanoobjekte auf Mo-O-Basis mit einer Vielzahl von Modifikationen einer Grundstruktur durch Selbstaggregation bei variablen Randbedingungen generieren lassen, können drastische Veränderungen – quasi durch die Wirkungsweise einer molekularen Schere – zu (großen) verknüpfbaren Ob…
The structural characterization of organotin compounds that are grafted onto insoluble cross-linked polymers has necessarily been limited to elemental analysis, infrared spectroscopy, and in a few instances, solid-state NMR spectroscopy. This important bottleneck in the development of such grafted systems has been add…
This paper provides the results on experimentally measured and numerically predicted surface tensions of undercooled liquid cobalt. The experiments were performed by using the oscillation drop technique combined with electromagnetic levitation. The simulations are carried out with the Monte Carlo (MC) method, where th…
Aza-crown ethers 2 and 3 with anthracene-containing pendant arms have been synthesised and characterised. Both compounds bind Group 1 metal cations in solution, forming complexes of 1:1 stoichiometry. The properties of compound 2 and its complexes have been studied by a range of techniques, including NMR, UV and fluor…
The temperature dependence of the ac susceptibility under pressure has been used to track the N\'eel temperature ${T}_{\mathrm{N}}$ of the Mott insulators ${\mathrm{L}\mathrm{a}\mathrm{M}\mathrm{n}\mathrm{O}}_{3}$, ${\mathrm{C}\mathrm{a}\mathrm{M}\mathrm{n}\mathrm{O}}_{3}$, and ${\mathrm{Y}\mathrm{C}\mathrm{r}\mathrm{…
Box clever: A very stable box-shaped cyclic tetramer (see picture) was formed from meso-pyridyl substituted meso–meso-linked zinc(II) diporphyrin, in which the porphyrin subunits are held in a rigorous perpendicular orientation.
Transgenic goats to spin webs! The silk of spider nets (see picture) possesses unique mechanical properties. By using suitable microbiological methods, a structurally similar fiber protein has recently been prepared that, after spinning, exhibits comparable strength and elasticity to natural spider silk. The American…