Materials Literature
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Abstract In the present work, fusion behavior, crystallinity, and mechanical properties of beverage bottle poly(ethylene terephthalate) (PET) was compared with those of the virgin material. Viscosimetry measurements, differential scanning calorimetric studies, impact and tensile determinations were made in both materi…
Abstract The electronic structures of 1,4-dihydropyrrolo[3,2-b]pyrrole and some of its alkyl derivatives were studied by means of He(I) photoelectron spectroscopy combined with the MNDO calculation and a first-order perturbation theoretical method. The first five bands of the parent pyrrolopyrrole are assigned, from t…
Abstract The kinetics of the direct synthesis reaction (Si + 2CH 3 Cl → (CH 3 ) 2 SiCl 2 ) were measured on a Cu 3 Si alloy containing 1.2 atom % Zn. Reaction was carried out in a differential reactor (520–595 K, 1 atm) attached to an ultrahigh vacuum (UHV) system. Auger spectroscopy was used to characterize the surfa…
The crystal structure of a REE-bearing vesuvianite from San Benito County, California, was determined using single-crystal X-ray diffraction methods. The sample with tetragonal space group P4/nhas cell parameters of a : 15J99(3) and c: ll.9l7(3) A. An R value of 6.640/o was reached for 287 4 unique reflections with I…
Abstract IR absorption spectra of the Mn 1− x Zn x Fe 2 O 4 ferrite‐spinel system are investigated in the frequency range ν = 800 to 40 cm −1 . The spectra of the second derivative d 2 T /dν 2 are obtained from the computer processed experimental transmission spectra ( T ). On their basis the two complex bands ν 1 and…
A new orange‐emitting phosphor, (Ca, Mg)S:Mn, was developed to replace a Cd compound, , which is potentially an environmental problem. With 1.5% Mg and 0.8% Mn, the emission color of (Ca, Mg)S:Mn is equal to the brightness of a 9 or 12 in. monochromatic tube and is 20% higher than that of . The addition of Mg as well…
Abstract The interfacial polycondensation of bisphenol A with isophthaloyl chloride and terephthaloyl chloride in dichloromethane with triethylbenzylammonium chloride as the catalyst was described. A well‐defined two‐phase system had been observed, so the concentration of bisphenolate in the aqueous phase could be det…
As a shaped charge jet stretches it breaks up into a series of particles along the jet axis of symmetry. These particles are frequently of approximately the same length, suggesting the existence of a critical wavelength for which the growth of an initial surface disturbance is greatest. Following the failure of earlie…
An experimental method for measurement of the low-temperature heat capacity at hydrostatic pressures and external magnetic fields was developed. Also, a suitable pressure-transmitting medium (Apieson-J oil) was found which had good thermal properties for the present method to measure the thermal and magnetic propertie…
Electrical characteristics, including degradation, of high K (\cong500) barium-titanate-based thick-film capacitors were studied. The leakage current of thick-film capacitors made from Ag/Pd thick-film conducting paste and high K dielectric has shown ohmic and super-ohmic (3/2 power voltage dependence) type behavior.…
As power supply frequencies approach the megahertz level, skin and proximity effects become significant factors to consider when calculating copper losses in transformers. Using electromagnetic theory and mmf diagrams in both space and time, a method that provides insight into the mechanism of skin and proximity effec…
It is now well established that thick films of transition-metal oxides such as NiO grow according to a modified Wagner mechanism by the diffusion of ions along grain boundaries in the oxide film. It is shown that the growth of thin films of this oxide is consistent with that of thick films if it is assumed that the sa…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of homopolymer molecular weight on the morphology of block copolymer/homopolymer blendsX. Quan, I. Gancarz, J. T. Koberstein, and G. D. WignallCite this: Macromolecules 1987, 20, 6, 1431–1434Publication Date (Print):June 1, 1987Publication History Published online1 Ma…
The material damping in beam-like specimens of aluminum and metal matrix com posites was measured. A unique apparatus to determine damping by free decay while the specimens are in free fall in a vacuum was used. The specimens tested include 2024-T3 and 6061-T4 aluminum, and unidirectional graphite/metal matrix specime…
Abstract Three clay samples (a kaolinite, a halloysite and an inseparable mixture of kaolinite-palygorskite-illite-montmorillonite) were, after a mild pretreatment, successfully tested as catalysts in the polymerization of styrene. The catalytic activity of the clay (measured by the conversion rate), the MW and the co…
Single‐phase solid solutions of2H crystal type in the SiC‐AIN system containing 50 and 75 mol% AIN were fabricated by hot‐pressing mixtures of SiC and AIN powders. Dense samples were subjected to thermal treatments over a range of temperatures between 1600° and 1900°C for a period of time up to 320 h. Transmission ele…
Electrochromic characteristics of familiar organic materials with relatively simple molecular structures, such as dimethyl terephthalate, are described. Coloration occurred at the cathode of all cells examined; the color spontaneously bleached upon removing the voltage. Electrochemically induced optical absorption was…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDefect-free, crystalline aromatic poly(etherketones): a synthetic strategy based on acetal monomersDonald R. Kelsey, Lloyd M. Robeson, Robert A. Clendinning, and C. Scott BlackwellCite this: Macromolecules 1987, 20, 6, 1204–1212Publication Date (Print):June 1, 1987Publicatio…
Abstract Three samples of poly(1,2‐cyclohexene oxide) were prepared with ZnEt 2 , (EtZnOMe) 4 , and [{MeOCH 2 CH(Me)OZnO(Me)CHCH 2 OMe} 2 · {EtZnO(Me)CHCH 2 OMe} 2 ] ([Zn‐MP] 2,2 ), respectively, as initiator. Each polymer sample was treated with butyllithium to form various decomposition products having double bonds…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic reactions of metalloporphyrins. 3. Catalytic modification of hydroboration-oxidation of olefins with rhodium(III) porphyrin as catalystYasuhiro Aoyama, Yasutaka Tanaka, Takeshi Fujisawa, Takamichi Watanabe, Hiroo Toi, and Hisanobu OgoshiCite this: J. Org. Chem. 198…