Materials Literature
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Samarium cobalt nanoparticles were prepared by ball milling under argon, both with and without surfactant. X-ray diffraction indicated a single SmCo/sub 5/ phase, with an average size of 25 nm from Debye-Scherrer analysis of the peak widths, but a broad size distribution based on TEM. SQUID magnetometry yielded the co…
Hydrotalcite structures containing copper, magnesium and aluminium in the metal hydroxide layers have been investigated for their potential as precursors to the formation of catalysts for the decomposition and reduction of nitrogen oxides. These CuIIMgIIAlIII hydrotalcites are catalytically active towards both the dec…
Polymers grafted or otherwise immobilized at surfaces are often used to stabilize particle suspensions in situations where nonspecific colloidal forces or specific chemical bonds act to coagulate the particles. Although the motivation is clear, criteria for steric stabilization are not well established for environment…
Redispersion of sintered Pt (0.6−1.0%)/Al 2 O 3 catalysts at 773 K under HCl/H 2 O/O 2 /N 2 atmospheres was studied by hydrogen chemisorption, temperature-programmed reduction (TPR), transmission electron microscopy (TEM) and in situ X-ray absorption spectroscopy (EXAFS) experiments. TPR and H 2 chemisorption results…
Fe(3,6-DBSQ)(3) has been prepared by reacting 3,6-di-tert-butyl-1,2-benzoquinone with Fe(CO)(5). The complex has been characterized structurally [orthorhombic, Pbca, a = 18.277(5) Å, b = 11.634(3) Å, c = 39.903(10) Å, V = 8485(4) Å(3), Z = 8, R = 0.063], electrochemically, and magnetically. Ligand-based redox couples…
In systemic radiation therapy, the absorbed dose distribution must be calculated from the individual activity distribution. A computer code has been developed for the conversion of an arbitrary activity distribution to a 3-D absorbed dose distribution. The activity distribution can be described either analytically or…
Here we discuss macroemulsions stabilized by interfacial colloidal films, in terms of the basic processes of colloid nucleation, colloid flocculation, and assembly in interfacial films. By monitoring the droplet-diameter, we present the effect of a variety of surfactants, additives, and organic solvents, as well as th…
A new quinary rare earth sulfide-halide compound has been synthesized and its structure determined by single-crystal X-ray diffraction. LaCa(2)GeS(4)Cl(3) crystallizes in the noncentrosymmetric hexagonal space group -P6(3)mc (No. 186) with Z = 2, a = 9.731(1) Å, and c = 6.337(1) Å. Lanthanum and calcium are mixed on a…
We have investigated the growth shape of two-dimensional (2D) poly(ethylene terephthalate) spherulites using a transmission electron microscope technique in order to examine the role of a diffusion-controlled mechanism in the growth process. At the growth front of the 2D spherulites, we found a terrace-like morphology…
An ab initio molecular orbital study is undertaken on the adsorption of N 2, O 2, and C 2 H 4 (adsorbate) on Ag−zeolite and Ag halides (adsorbent). Geometry optimization is performed at the HF/3-21G level, while MP2/3-21G with natural bond orbital calculations are performed to obtain energies, atomic charges, orbital…
Deposition of anatase TiO2 thin films on soda-lime glass has been achieved by firing an adhered precursor titanium(IV) complex of ethylenediamine-N,N,N′,N′-tetraacetic acid (H4edta) between 450 and 550 °C in air. The coating solution was prepared by the reaction of a neutral [Ti(H2O)(edta)] complex, obtained from TiCl…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTStability of Carbon Nitride Materials at High Pressure and TemperatureAndrew J. Stevens, Takaaki Koga, Carl B. Agee, Michael J. Aziz, and Charles M. LieberView Author Information Department of Chemistry and Chemical Biology Division of Engineering and Applied Sciences…
The diradical 1,1‘,5,5‘-tetramethyl-6,6‘-dioxo-3,3‘-biverdazyl, 6, crystallizes in a monoclinic unit cell with a = 4.224(1), b = 17.378(2), c = 7.529(1) Å, β = 96.02(1)°, space group P 2 1 / c (No. 14). The crystal structure of 6 shows local D 2 h symmetry. ESR measurements in a frozen chloroform solution indicate tha…
The crystallization and microphase separation of compatible mixtures of tetrahydrofuran−methyl methacrylate diblock copolymers (PTHF- b -PMMA) with a tetrahydrofuran homopolymer (PTHF) were studied by means of synchrotron small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC). The crystallizat…
Nd/sub 2/Fe/sub 14/B is currently the best (highest energy product) hard magnet available. Like most permanent magnetic materials, it is rather brittle. The fracture toughness of specimens of commercially available hard magnets were measured using a chevron notch, three-point bend test. Values for Nd/sub 2/Fe/sub 14/B…
Measurements of the sorption isotherms (at 298 K) for Ar, O 2, and N 2 in several polyaniline emeraldine base (PANi-EB) forms were made (as-cast film, powder, and fully undoped film) over the pressure range 100−1300 kPa. Model fits of the sorption isotherms were made using a modified Flory−Huggins equation (MFHE) and…
Previously, we have developed a colloidal dextran-stabilized monocrystalline iron oxide nanocompound (MION-46) as a magnetic label for magnetic resonance imaging (MRI). In an effort to use this magnetic label to visualize pancreatic receptor function by MRI in vivo, we investigated the potential of secretin as a vecto…
When a specimen surface carrying a high-frequency line grating is examined under a scanning electron microscope (SEM), moiré fringes are observed at several different magnifications. The fringes are characterized by their spatial frequency, orientation, and contrast. These features of the moiré pattern depend on the s…
Head-to-head regioregular poly( p -phenylene)s (PPPs) were synthesized via Ni(0)-catalyzed polymerization of 2,2‘-disubstituted 4,4‘-bis[(methylsulfonyl)oxy]biphenyls ( 9 ). The corresponding regioirregular PPPs were prepared by the Ni(0)-catalyzed homopolymerization of 2-substituted 1,4-bis[(methylsulfonyl)oxy]benzen…
A spirocyclic initiator was synthesized from dibutyltin oxide and pentaerythritol. This spirocyclic distannoxane was characterized by elemental analyses, NMR spectroscopy, and a stoichiometric reaction with γ-thiobutyrolactone. ε-Caprolactone (ε-CL) was polymerized in bulk at 70 °C with variation of the monomer/initia…