Materials Literature
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X-ray photoemission measurements of high purity CuI are presented. XPS studies of Cu compounds in this laboratory have been motivated by the need to identify species on chemically etched high temperature superconductor surfaces [see R. P. Vasquez, M. C. Foote, and B. D. Hunt, J. Appl. Phys. 66, 4866 (1989)].
A series of fluorinated polyinides and fluorinated polyimides containing heterocyclic moieties were prepared and investigated to determine their dielectric constants, dielectric constants as a function of relative humidity (RH) and thermal properties. Thle fluorinated polyimides containing heterocyclic moieties were p…
Abstract The Rietveld method requires a two-part starting model (see Chapter 1 and elsewhere), a structural model based on approximate atomic positions and a non-structural model which takes into account the contributions of individual line profiles in terms of analytical or other differentiable functions. Both must b…
Abstract Since the initial studies of chlorite polytypes, it has been suggested that the stability of the various polytypes may be a function of the temperature at which the mineral formed; however, few studies have been performed in which polytypes of chlorite in a specific suite of samples have been determined and c…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and properties of an optically active helical bis-cobaltocenium ionAdam M. Gilbert, Thomas J. Katz, William E. Geiger, Matthew P. Robben, and Arnold L. RheingoldCite this: J. Am. Chem. Soc. 1993, 115, 8, 3199–3211Publication Date (Print):April 1, 1993Publication Hi…
The hpaB gene encoding an aromatic hydroxylase of Escherichia coli ATCC 11105, a penicillin G acylase-producing strain, has been cloned and expressed in E. coli K-12. This gene was located near the pacA gene coding for penicillin G acylase. The hydroxylase has a molecular mass of 59,000 Da, uses NADH as a cosubstrate,…
Raman-heterodyne-detected paramagnetic resonance has been used to study the level anticrossing in the $^{3}$A state of the N-V defect in diamond. The electron-paramagnetic-resonance (EPR) frequencies are well accounted for by a triplet-spin Hamiltonian. Comparison of the EPR spectra with the calculated transition dipo…
A modification of the extended Hildebrand equation is proposed to estimate the solubility of an organic drug in solvent mixtures. The equation accurately reproduces the solubility of four sulphonamides in dioxane-water mixtures without requiring the heat of fusion of the solute. A single equation is obtained for predi…
For protecting mild steel from corrosion, amino-trimethylidenephosphonic acid (ATMP) was more effective than 1–hydroxyethylidene diphosphonic acid (HEDP), N.N–dimethylidenephosphonoglycine (DMPG), 1–ethyl-phosphonoethylidenediphosphonic acid (EEDP), and ethylenediaminetetramethylidenephosphonic acid (EDTMP). A 20-min…
Spontaneous electron transfer, along with anion uptake by doping, form the basis of a new concept for the reduction of toxic Cr(VI) using an electronically conductive polymer, e.g. , polypyrrole. Proof of concept experiments are described which show that aqueous sulfuric acid solutions containing 5–100 ppm Cr(VI) can…
Abstract Free‐radical reactions, which are relevant in the chemical modification of polymeric materials, are discussed in relationship to their influence on random chain scission. A mathematical model is developed to calculate the entire molecular weight distribution (MWD) with the degree of chain scission as the sole…
Using potentiodynamic and transient electrochemical methods and weight loss shows that N-alkylbetaines are good inhibitors of iron corrosion in HCl at concentrations around the critical micelle concentration (CMC). High corrosion inhibition is observed when medium pH value is lower than organic compound pKa. When the…
La 2 Ti 2 O 7 , M r =485.613, monoclinic, P2 1 , a=7.812 (2), b=5.5440 (7), c=13.010 (2) A, β=98.66 (1) o , V=557.0 (4) A 3 , Z=4, T=298 K, D x =5.790 Mg m -3 , λ(Mo Kα)=0.71073 A, μ=17.86 mm -1 , F(000)=856. The crystals are twinned. The twin I and twin II intensities are superimposed in reciprocal-lattice layers wit…
The purpose of this study was to compare the heterogeneity and median charge of FSH and LH in serum at different phases of the normal human menstrual cycle. Serum specimens were obtained during the follicular phase [9.0 +/- 1.9 (+/- SD) days before the midcycle], at the midcycle LH peak, and during the luteal phase (9…
Formation of a protective surface layer [a layer of products through which transport (diffusion) of aqueous reactants or products is rate-determin ing] during silicate-mineral weathering requires that (1) elements normally considered immobile (e.g., Al, Fe) behave conservatively; and (2) the volume ratio of product to…
Abstract Polyethylene foam experiments were conducted on a twin screw foam extruder to study the process effects upon foam nucleation. The results indicate that, other than quantity of nucleators, throughput rate and die opening are important process parameters, underscoring the importance of shear in the die on nucle…
Transmission measurements have been performed in reduced ${\mathrm{SrTiO}}_{3}$ between 300 and 17 K for different concentrations of oxygen vacancies. A midinfrared absorption band has been observed, whose behavior with doping and temperature is accounted for by an intraband scattering process, phonon or disorder assi…
In this study, we have confirmed the ability of liposome-encapsulated doxorubicin to modulate drug resistance, as previously observed in CH LZ cells (Thierry et al., Cancer Commun. 1, 311-316, 1989), in two human multidrug-resistant (MDR) cell lines, the breast cancer MCF-7/ADR cell line, and the ovarian carcinoma SKV…
Abstract The mechanism of esterification of cotton cellulose by a polycarboxylic acid was investigated using Fourier transform infrared spectroscopy (FT‐IR). The infrared spectroscopic data indicate that a polycarboxylic acid esterifies with cotton cellulose through the formation of an acid anhydride intermediate. A f…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDihydroazulene/vinylheptafulvene photochromism: effects of substituents, solvent, and temperature in the photorearrangement of dihydroazulenes to vinylheptafulvenesHelmut Goerner, Christian Fischer, Sebastian Gierisch, and Joerg DaubCite this: J. Phys. Chem. 1993, 97, 16, 41…