Materials Literature
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An inversion barrier between enantiomorphic saddle conformers of nickel(II)ccccc-octaethyl-pyrrocorphinate in solution is observed by 1H n.m.r. spectroscopy.
Skin forms a link through which the forces required to hold and manipulate objects are transmitted from the musculoskeletal system to the objects; while these forces are necessary for most work, excessive forces can be injurious. This paper discusses some of the mechanical properties of skin and discusses how they are…
Crystals of the monoclinic compound Cu(SeO 2 OH) 2 were synthesized under hydrothermal conditions. The crystal structure was refined to R w = 0.023 for 952 unique data up to sin θ / λ = 0.81 Å −1 ( a = 5.7662(4) Å, b = 7.3521(6) Å, c = 6.4474(5) Å, β = 93.28(1)°, Z = 2, space group P 2 1 / n ). The Cu atom is [4 + 2]…
Observations of damage during the creep rupture of poly‐crystalline alumina have revealed an important influence of shear bands on the failure process. The shear bands are regions of appreciable damage, consisting of high densities of facet‐sized cavities. The cavities within the bands become crack nuclei at shear ban…
The adsorption of NO on pure MgO at 77 K gives N2O2(cis) dimers on {100} faces and NO–2(nitrite), N2O2–2(hyponitrite) and N2O2(cis) dimers on edges and steps. The hyponitrite anions (which are the precursors of N2O gas formation) and the dimeric N2O2(cis) species are absent at room temperature, while the NO–2 species…
Some solutions of rigid polymers like DNA or PBLG display at the same time cholesteric order and local hexagonal order. The coexistence of two such orders is impossible on long distances. Two cylindrical geometries of molecular arrangements, extending transversally on a distance of the order of the pitch, and achievin…
The crystal structures and the magnetic properties of two novel complexes, of formula [Cu2(C17H27N4O)(C2H3O2)L]PF6, L = N3 or NCO, with a 1,1-azido or cyanato bridge in addition to phenolato and acetato bridges have been investigated and the relevance of the results to the fields of molecular magnetism and bioinorgani…
Abstract Die neuen Verbindungen Cs 2 P 2 S 6 und K 2 P 2 S 6 kristallisieren orthorhombisch in der Raumgruppe Immm, Z = 2 mit den Gitterkonstanten und sind dem Tl 2 P 2 S 2 isotyp. Sie enthalten diskrete P 2 S 2 2− ‐Anionen als Baugruppen. Zwei PS 4 ‐Tetraeder sind über eine gemeinsame Kante zum Hezathiometadiphosphat…
Sustained release systems were made by incorporating 5-fluorouracil (5-FU) in an ethylene-vinyl alcohol copolymer. When exposed to aqueous medium, the delivery systems released the drug slowly and continuously. Upon exposure to ultrasound, the drug was released at a much higher rate. Release rates returned to base lin…
On considere que des modifications de la raie centrale de resonance magnetique nucleaire de 11 β des groupes borates en coordination 4 peuvent se produire si du fluor est incorpore dans le reseau vitreux. On discute de ce phenomene et on le prouve en comparant la theorie avec l'experience et on reconsidere les etudes…
The structures of the complexes [Cu2(L1)2(N3)2][ClO4]2(1){ L1= 1-(imidazol-4-yl)-2-[(2-pyridylmethylene)amino]ethane} and [Cu2(L1)2(N3)3]Cl·2H2O (2) have been determined by X-ray methods. Complex (1) contains discrete [Cu2(L1)2(N3)2]2+ cations which are located at centres of inversion. The geometry around each copper(…
An investigation was undertaken to elucidate the preparation conditions and magnetic properties of W-type hexaferrite powders with the formula AM 2 Fe 16 O 27 (A=Ba or Sr, M=Fe 2+ , Zn+Cu, Zn+Cd, Zn+Mg). A pure W-phase was formed by firing a mixture of carbonates and oxides in the appropriate molar ratio at 1200^° ∼14…
The infrared spectra of Cu(en)(TCNQ)2 and Cu(en)2(TCNQ)2(en: ethylenediamine, TCNQ: 7,7,8,8-tetracyanoquinodimethane) have been shown to exhibit totally symmetric TCNQ Ag bands activated by a vibronic process in addition to inherently i.r.-active Bu bands. In the spectrum of Cu(en)2(TCNQ)3 some Ag modes were developed…
Bis[1,2,5]thiadiazolo-tetracyanoquinodimethane (1) was prepared and found to form a highly conductive complex with tetrathianaphthacene.
A prerequisite for the aseptic packaging of food is the UHT or HTST process used for sterilizing the food. These processes are defined. The history, microbiology, and engineering principles of aseptic processing and packaging are covered. Attainment of sterility and acceptable levels of spoilage are discussed. Methods…
The catalytic effect of the mercury(II) ion on metalloporphyrin formation provides the basis for determination of the stability constant of the zinc (II) porphyrin, the rate of formation of which is extremely slow in the absence of mercury(II).
Electrochemical properties of {[NBun4][BF4]·3 toluene} are described; the hydrocarbon medium allows, for the first time, the observation of all members of the [Fe4S4(SPh)4]n– electron-transfer Series, n= 1–4.
The hydrogen reduction of a series of alumina- and silica-supported iron–ruthenium catalysts has been studied in situ by iron-57 Mössbauer spectroscopy. The data, complemented by results from temperature-programmed reduction experiments, show that ruthenium enhances the reducibility of iron and that the metal–support…
The experimental approach for carrying out electrochemical impedance measurements for coated metals is described. Models for the impedance behavior have been developed for different coating systems, and methods for the analysis of experimental impedance diagrams in terms of coating and interface properties and their c…
Conformational analysis studies on the tertiary structure of cello-tetraose, methyl-β-cellotetraoside, and single cellulose chains were carried out by using calculation of van der Waal, H-bond, electrostatic, and torsional energy interactions between the atoms and molecular groups in both the skeleton and side chains…