Crystal Structure of As2O5
The first single crystals of As 2 O 5 have now been obtained by annealing amorphous As 2 O 5 under oxygen excess pressure and with careful exclusion of moisture. They were suitable for X‐ray structure analysis.
Materials Literature
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Spectral properties of (Et/sub 4/N)/sub 2/UI/sub 6/ and (Et/sub 4/N)/sub 2/UF/sub 6/
The optical spectra of (NEt/sub 4/)/sub 2/UI/sub 6/ and (NEt/sub 4/)/sub 2/UF/sub 6/ are presented and analyzed. With these data the electrostatic, spin-orbit, and crystalline field parameters have been obtained for the series of octahedral compounds UX/sub 6//sup 2 -/ (X = F, Cl, Br, I). The Slater parameter F/sup 2/…
A rectangular-bore gas gun
Design details and measured performance are presented for a laboratory gas gun with a novel rectangular bore. Projectiles weighing 0.5 g have been accelerated to 300 m s -1 . This design eliminates axial rotation of the projectile which is possible in a cylindrical-bore gun, and provides important advantages in some i…
Verzug von Stählen infolge Wärmebehandlung
Abstract Verzug umfaßt Maß‐ und Formänderungen. Maßänderungen entstehen durch Wärmespannungen und Gefügeumwandlungen, insbesondere beim Härten und Anlassen. Wärmespannungen bewirken abmessungsabhängige, Gefügeumwandlungen abmessungsunabhängige Maßänderungen. Das Maßänderungsverhalten ist eine Systemeigenschaft. Anlaßv…
Infrared Reflectance and Dielectric Properties of Pyrolytic Graphite for E ∥ c Polarization
Abstract Normal incidence reflectance measurements with E ∥ c polarization are performed on polished surfaces of pyrolytic graphite for 15 meV < ħω < 500 meV and the dielectric function ϵ ∥ (ω) is derived from the data by Kramers‐Kronig analysis. The function ϵ ∥ (ω) is characterized by a background dielectric c…
X‐ray structure determination of isotactic poly(2‐vinylpyridine)
Abstract The structure of isotactic poly(2‐vinylpyridine) has been determined from x‐ray fiber data utilizing rigid‐body least‐squares refinement techniques. The polymer exists as a threefold helix with three chains passing through a hexagonal unit cell having the dimensions a = b = 15.49 Å and c = 6.56 Å (fiber axis)…
X-ray diffraction study of the structure of 1-propanol at –25°C
Molybdenum Kα X-radiation, monochromated by an NaCl single crystal, was scattered in 1-propanol at -25°C. The angular distribution of the scattered X-ray intensity was determined and used for the calculation of the experimental pair function. On the basis of some models of the structure of liquid 1-propanol, the theor…
The carbonyl scrambling processes in the isomeric pentacarbonylguaiazulenediiron and homologous ruthenium molecules; a novel mechanism for the internuclear processes
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe carbonyl scrambling processes in the isomeric pentacarbonylguaiazulenediiron and homologous ruthenium molecules; a novel mechanism for the internuclear processesF. Albert Cotton, Brian E. Hanson, John R. Kolb, Pascual Lahuerta, George G. Stanley, B. Ray Stults, and Alan…
Carbon-13 Spin Relaxation Parameters of Semicrystalline Polymers. Linear Polyethylene
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 Spin Relaxation Parameters of Semicrystalline Polymers. Linear PolyethyleneR. A. Komoroski, J. Maxfield, F. Sakaguchi, and L. MandelkernCite this: Macromolecules 1977, 10, 3, 550–556Publication Date (Print):May 1, 1977Publication History Published online1 May 2002P…
Pyrolysis–molecular weight chromatography–vapor‐phase infrared spectrophotometry: An on‐line system for analysis of polymers. III. Thermal decomposition of polysulfones and polystyrene
Abstract The thermal decomposition of poly(butene‐1 sulfone), poly(pentene‐1 sulfone), poly(hexene‐1 sulfone), poly(styrene sulfone), and polystyrene was investigated in helium at a heating rate of 20°C/min using an experimental system which consists of a programmable pyrolyzer, a thermal conductivity detector, a mass…
The chemistry of the collagen cross-links. Characterization of the products of reduction of skin, tendon and bone with sodium cyanoborohydride
Reduction of tissues with sodium cyanoborohydride at pH7.4 gave results identical with those obtained by KBH4 treatment. On reduction with sodium cyanoborohydride at pH 4.4, however, a previously undetected basic compound was formed and was identified by mass spectrometry and chemical degradation techniques as dihydro…
FIBER CONTENT, PARTICLE-SIZE DISTRIBUTION AND SOME RELATED PROPERTIES OF FOUR PEAT MATERIALS IN EASTERN CANADA
The effects of dispersion and sieving on the determination of fiber content was studied using four peat materials selected for their range of properties. In addition, a method of particle-size analysis of peat materials and chemical characterization data of the particular-size fraction are presented. Controlling the s…
Applications of synchrotron radiation to protein crystallography. II. Anomalous scattering, absolute intensity and polarization
The synchrotron X-ray beam produced by the SPEAR storage ring at the Stanford Linear Accelerator Center has been used as a tuneable and intense source for single-crystal-protein diffraction experiments. A measurement of the absolute intensity of a focused, monochromatized X-ray beam gave a value of 3 × 109 photons s-1…
Electrons in glass
An outline is given of some of the steps which in the last ten years have led to an understanding of many of the properties of conduction and valence bands in non-crystalline materials. The concept of a mobility edge is described and some of the experimental evidence for its existence is presented. A discussion is giv…
Kristallstruktur von B2S3: B2S2‐Vierringe neben B3S3‐Sechsringen
Die Röntgen‐Strukturanalyse von B 2 S 3 scheiterte bisher an der schlechten Qualität des Kristallmaterials. Jetzt konnten Einkristalle erhalten werden, an denen sich die Struktur aufklären ließ. magnified image
Graft copolymers of polysaccharides with thermoplastic polymers. A new type of filled plastic
Abstract A series of starch graft copolymers and one cellulose graft copolymer were prepared containing 40‐50 percent synthetic polymer. The monomers used (styrene, methyl methacrylate, methyl acrylate, and butyl acrylate) were chosen to give grafted synthetic polymers with varying glass transition temperatures (T g )…
Sodium Diffusion in Glass: I, Single‐Alkali Silicate
The isotope effect for 22 Na/ 24 Na diffusion was measured for three 25‐mol% alkali‐silicate glasses. A multiple diffusion mechanism wherein the Na ions diffuse both singly (vacancy mechanism) and in pairs (interstitialcy mechanism) provided the best agreement with the experimental data. According to this tentative mo…
Static and Impact Properties of Laminated Hybrid Composites
Abstract The static and impact properties of hybrid composite systems containing various high performance fibers in an epoxy matrix have been studied as a function of lamination configuration. From instrumented impact test data, fracture initiation and propagation energies were calculated and reported in terms of a me…
Scanning Electron Microscopy
Abstract not Available.
Polyurethane interpenetrating polymer networks. V. Engineering properties of polyurethane–poly(methyl methacrylate) IPN's
Abstract The engineering properties of polyurethane–poly(methyl methacrylate) simultaneous interpenetrating networks (SIN's) were evaluated. The hardness behavior reflected the observed phase inversion in the electron‐microscopic studies. The maximum ultimate tensile strength was observed at 85% polyurethane–15% poly(…