Materials Literature
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We have investigated optical properties of thermally grown SiO 2 layers within the thickness range 150 to 500 nm. The complex dielectric constant ε(ν˜) can be represented by six Lorentz-Gauss oscillators, which allow us to determine the optical constants of SiO 2 films by fitting IR transmittance spectra. The spectra…
The current injection into metal/porous Si/bulk Si diodes is investigated by transport and photoresponse measurements. Under low forward bias, the diode current is determined by the space charge region at the porous Si/bulk Si interface. The activation energy of the photovoltage shows that holes are injected into poro…
The liquid-crystal properties are reported for a series of multinuclear phthalocyanines containing either two or three macrocyclic ring units. All but one of the compounds, the ‘dimer’ with the shortest spacer group between the two rings, exhibit discotic columnar mesophase behaviour. On cooling from the isotropic liq…
The molecular and crystal structure of [Fe3(CO)12] has been reinvestigated from single-crystal X-ray diffraction data collected at 100, 160, 250 and 320 K. The asymmetric bridging carbonyl ligands become progressively more symmetric as the temperature is decreased. At the lowest temperature the molecule possesses near…
The structure of two polymorphs of manganese dioxide, λ-MnO 2 and γ-MnO 2 and the spinel oxide LiMnO 2 have been refined by Rietveld analysis of powder neutron diffraction data. λ-MnO 2 , Fd3m, a=8.0639(3) A, R Bragg =1.81%, γ-MnO 2 , Pnam, a=9.3229(11) A, b=4.4533(7) A, c=2.8482(3) A, R Bragg =1.34% and LiMn 2 O 4 ,…
The triple-decker chromium complexes [(η5-C5Me5)Cr(µ2:η5-P5)Cr(η5-C5Me5)]+[A]–(A = PF6, SbF6) can be prepared in high yield by oxidation of [(η5-C5Me5)Cr(µ2:η5-P5)Cr(η5-C5Me5)] with either [Fe(η5-C5H5)2]+[A]–(A = PF6, SbF6); the single crystal X-ray structure determination for [(η5-C5Me5)Cr(µ2:η5-P5)Cr(η5-C5Me5)]+[SbF…
Mechanical and electrical properties of filled epoxy were evaluated by accelerated aging under high humidity and high temperature. Significant changes in these properties arose from the slight water absorption. The presence of internal and irreversible flaws such as microscopic damage probably associated with the elas…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCharacterization of magnesium-aluminum mixed oxides by temperature-programmed reaction of 2-propanolChristopher T. Fishel and Robert J. DavisCite this: Langmuir 1994, 10, 1, 159–165Publication Date (Print):January 1, 1994Publication History Published online1 May 2002Publishe…
A planar phthalocyanine–pyrazinoporphyrazine heterodimacrocycle and its dizinc complex have been synthesized and characterized; they are similar in several aspects to planar homodinuclear congeners but their most notable difference is a lack of fluorescence.
A theory describing layers of polymer chains grafted to a flat surface (polymer ‘brush’) is developed. We consider a brush of chains with arbitrary extensibility and, within the framework of molecular field theory, we suggest a general scheme for calculating the self-consistent pseudo-potential, which determines the s…
Visible light irradiation of a reaction mixture involving tetraphenylporphyrinatoantimony(V)(SbVTPP){[SbVTPP(OMe)Br]Br 1 or [SbVTPP(OH)2]OH 2}, methylviologen (MV2+), hydroxide ion and cyclohexene 6 in acetonitrile–water (95:5) under degassed conditions induced formation of MV˙+(one-electron reduced product of MV2+),…
For obtaining shorter wavelength laser glass without using nonlinear optical crystal, The fluorescence properties of Eu3+ were investigated in various glasses. The Eu3+ dopedborosilico-phosphate glass has the highest emission intensity of 5D0→→7F2 transition comparedwith other glasses, because it can be doped with hig…
The effect of oxygen plasma treatment of fiber on the adhesion between regenerated cellulose fiber and polyethylene (PE) was investigated using the single-fiber fragmentation test. In addition to allowing the determination of the interfacial shear strength, the fragmentation test provided a great deal of useful inform…
The effect of austenitizing temperature were investigated on the microstructure and mechanical properties of 12%Cr steel. Low-temperture austenitizing below 1000°C induced the carbide coarsening during subsequent tempering at 750°C for 1 hr due to the nucleation effect of undissolved M23C6. The large and spheroidized…
ABSTRACT The influence of added lipids (which mimic the endogeneous lipid pool of wine) on the foam behavior of sparkling base wines at various ethanol concentrations was investigated by measuring the foam expansion, foam stability and the Bikerman coefficient. Depending on their physical state, molecularly dissolved…
Internal and external factors that influence the morphology of crystals are studied based on an inhomogeneous cell model. After discussing the reason of the failure of two basic assumptions, the equivalent wetting condition and the proportionality condition, the influence of the ambient phase is explicitly taken into…
Les seuils Al-L2,3 et Al-K ont t enregistrs par spectroscopie des pertes d'nergie (EELS) pour les minraux Bryl, Orthoclase, Sillimanite, Andalousite et Kyanite. L'origine de certains pics visibles sur ces seuils a t attribue des transitions vers des orbitales molculaires inoccupes dans les clusters AlO5-4 et AlO9-6, p…
(opens in new window) Buy Article (opens in new window) Permissions and Reprints (opens in new window) All articles of this category (opens in new window) The condensation of 2,3-dicyano-5,6-diethoxycarbonylpyrazine with a metal salt affords tetra-2,3-(5,6-diethoxycarbonylpyrazino)porphyrazine, which upon mild hydroly…
Sol-gel thin coatings of ZrO2, SiO2, 70SiO2-30TiO2 and 88SiO2-12Al2O3 compositions (mole %) have been prepared from sonocatalyzed sols and deposited by dip-coating technique on 316L stainless steel foils. The influence of the coatings on the chemical corrosion of the substrate has been measured through potentiodynamic…
We have studied the effect of an applied field on a system of particles interacting with a Lebwohl-Lasher potential, enclosed in a polymer-dispersed liquid-crystal droplet with radial boundary conditions. We have used Monte Carlo simulations on a wide temperature range for systems of N=302 and 5832 particles with posi…