Materials Literature
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Phase equilibria in the system MgO‐B 2 O 3 were investigated using DTA and quenching techniques. The system contains 4 invariant points. The compounds MgO·2B 2 O 3 and 2MgO·B 2 O 3 melt incongruently at 995° and 1312°C, respectively, whereas 3MgO·B 2 O 3 melts congruently at 1410°C. A eutectic occurs at 1333°C and 71%…
A new analytic approximation to atomic incoherent X-ray scattering intensities is proposed. Unlike other approximations in the literature, the present function has the correct asymptotic behaviour at both large and small values of s. Fits to the incoherent intensities calculated by Cromer are presented for all atoms f…
Some of the limitations inherent in the use of directly measured contact angles for.the determination of filament wetta bility are discussed, and an alternate approach based on the Wilhelmy balance principle is presented. Mathematical interpretation of data obtained allows for determination of wettable cross-sectional…
When vanadium dioxide, VO2, undergoes its semiconductor-to-metal transition at 68 °C its reflectivity decreases by about a factor of 2 throughout the visible range. By using a thin VO2 film on a vanadium substrate we were able to achieve a much higher contrast between the reflectivities of the two VO2 phases. The VO2…
Crystallization sequences of glasses with compositions in the tridymite primary phase field of the MgO‐Al 2 O 3 ‐SiO 2 system were studied by DTA, X‐ray diffraction, and other techniques. Crystallization was catalyzed by the addition of 7 wt% of either ZrO 2 or TiO 2 . Up to 10 wt% CeO 2 was also added to some glasses…
Abstract Various aspects of polyphosphazene chemistry are reviewed. Stable poly (organophosphazenes) can be prepared from an inorganic precursor, poly(dichlorophosphazene), by careful control of polymerization and substitution reaction conditions. The bulk structure and properties of polyphosphazenes are discussed, an…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTX-ray photoelectron spectroscopy of inorganic and organometallic compounds of molybdenumSamuel O. Grim and Luis J. MatienzoCite this: Inorg. Chem. 1975, 14, 5, 1014–1018Publication Date (Print):May 1, 1975Publication History Published online1 May 2002Published inissue 1 May…
A study of the phase transitions in WO3 crystals by Raman and absorption spectroscopy reveals that WO3 possesses two stable (or metastable) modifications at room temperature, differing slightly but definitely in their physical properties. Measurements of electrical conductivity show that both are insulators at low tem…
Preface Symbols used Abbreviations 1. Giant cells as experimental material 2. Two hundred years: early physiology 3. Water relations 4. Permeability to nonelectrolytes 5. Compartments and ionic concentrations 6. Ionic fluxes and kinetic models 7. Electrical properties of membranes 8. Action potentials in charophyte ce…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis, stereochemistry, and structure-related properties of .alpha.,.beta.,.gamma.,.delta.-tetraphenylporphinatoiron(II)James P. Collman, J. L. Hoard, Nancy Kim, George Lang, and Christopher A. ReedCite this: J. Am. Chem. Soc. 1975, 97, 10, 2676–2681Publication Date (Pri…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBonding capabilities of transition metal carbonyl fragmentsMihai Elian and Roald HoffmannCite this: Inorg. Chem. 1975, 14, 5, 1058–1076Publication Date (Print):May 1, 1975Publication History Published online1 May 2002Published inissue 1 May 1975https://pubs.acs.org/doi/10.10…
An extensive calculation of the optical-phonon-assisted transition rates for non-adiabatic electronic hopping motion in a solid is presented. Holstein's Molecular Crystal Model is used as a basis for study and the computation involves no restrictions on either the magnitude of the electron-lattice coupling strength, t…
Abstract The set of synthetic polytripeptides and polyhexapeptides which can adopt a triple‐helical form constitute a good model system for investigating collagen structure. Here we consider previous and new infrared spectroscopic studies on collagen and present the infrared spectra of a number of polymers with collag…
The relation between the corrosion rate of steel in carbonic acid and the CO2 partial pressure was determined by means of weight loss and polarization resistance measurements. This relation is compared with that expected for completely dissociated acids, and appears to be significantly different. A theoretical analysi…
Granular metal films (50–200,000 Å thick) were prepared by co-sputtering metals (Ni, Pt, Au) and insulators (SiO2, Al2O3), where the volume fraction of metal, x, was varied from x = 1 to x = 0.05. The materials were characterized by electron micrography, electron and X-ray diffraction, and measurements of composition,…
Abstract The synthesis and isolation of heptafulvene ( 1 ) and sesquifulvalene ( 2 ) is reported: Acetoxy‐tropylium‐fluoroborate ( 10 ) may be prepared by addition of tropone to acetyl‐fluoroborate at low temperatures. The tropylium salt reacts easily with methyllithium and sodium cyclopentadienide to give the acetoxy…
Abstract The substituted benzylideneanilines 2–7 and the respective 3 H ‐indoles 9–14 have been synthesized. A comparison of their electronic absorption spectra shows it is likely that 4‐nitrobenzylidene‐4′,‐dimethylaminoaniline ( 6 ) has a planar conformation.
Terbium reacted with DNA and chromatin to form a complex in which terbium acted as a sensitive fluorescent probe. By measuring the narrow-line emission of Tb-3+ when DNA is selectively excited, the relative amount of Tb-3+ bound to the DNA can be calculated. Terbium was bound to DNA until one Tb-3+ was present for eac…
It is argued that, in a process involving ejection of an inner shell electron by an unpolarized beam of photons and subsequent atomic reorganization via Auger ejection, the two ejected electrons can be strongly correlated in direction. In general, the detailed form of the correlation will depend on both photoionizatio…
A detailed investigation is reported of electrical properties of polycrystalline PbZrO3 samples around the points of phase transitions from the antiferroelectric state (AFE) to the ferroelectric (FE) and paraelectric (PE) states. The influence is studied of a constant electrc field on the phase transitions AFE ⇄ FE an…