Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Abstract Fourier transform (FT) Raman spectroscopy has been proved to be an adequate technique for the study of the quantitative structural changes which take place in poly(ethylene terephthalate) on annealing. The two‐phase conformational model proposed previously in the infrared domain using photoacoustic FTIR has b…
Abstract The increasing costs of disposing of fly ash create an urgent need to find potential uses, one of which is land application to improve physical or chemical properties of soils. Because fly ash contains considerable amounts of B, which is often deficient in Southeastern soils, B release from fly ash and its up…
The hybrid Bacillus (1,3-1,4)-beta-glucanase H(A16-M), consisting of 16 N-terminal amino acids derived from the mature form of the B. amyloliquefaciens enzyme and of 198 C-proximal amino acids from the B. macerans enzyme, binds a calcium ion at a site at its molecular surface remote from the active center [T. Keitel,…
Linear polymers, such as polyethylene, are thermoplastics, which can be remolded many times and have a degree of solubility, are considered. The properties discussed include: molecular structure, molecular motion, and dielectric relaxation.>
Carbon nanotubes were prepared by dc arc-discharge evaporation of graphite rods, by varying the pressure and the kind of atmospheric gas. Nanotubes, included in the carbon deposit on the cathode, were observed by scanning electron microscopy (SEM).
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSegmented Polyurethane Elastomers with Liquid Crystalline Hard Segments. 1. Synthesis and Phase BehaviorWeiming Tang, Richard J. Farris, William J. MacKnight, and Claus D. EisenbachCite this: Macromolecules 1994, 27, 10, 2814–2819Publication Date (Print):May 1, 1994Publicati…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and the Smectic Mesophase of Copolymers Containing a Mesogenic (Carbazolylmethylene)aniline Group as the Electron Donor and a (4'-Nitrobenzylidene)aniline Group as the Electron AcceptorYozo Kosaka, Takashi Kato, and Toshiyuki UryuCite this: Macromolecules 1994, 27,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxovanadium(V) Alkoxide Derivatives of 1,2-Diols: Synthesis and Solid-State 51V NMR CharacterizationDebbie C. Crans, Robert A. Felty, Haojiang Chen, Hellmut Eckert, and Nandini DasCite this: Inorg. Chem. 1994, 33, 11, 2427–2438Publication Date (Print):May 1, 1994Publication…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMorphology of Highly Textured Poly(ethylene)/Poly(ethylene-propylene) (E/EP) Semicrystalline Diblock CopolymersPeter Kofinas and Robert E. CohenCite this: Macromolecules 1994, 27, 11, 3002–3008Publication Date (Print):May 1, 1994Publication History Published online1 May 2002…
Abstract Static and dynamic light scattering measurements were performed on a glass‐forming polymer, poly(methyl‐ p ‐tolylsiloxane) (PMpTS; T g =−17°C), in a temperature range of 30°C to 120°C. It was found that long‐range density fluctuations, so‐called clusters, are observed in this polymer. They are characterized b…
As-grown homoepitaxial diamond surfaces fabricated by chemical vapor deposition are terminated by hydrogen, and are expected to have a low density of surface states. On such diamond surfaces, high-quality Schottky contacts have been obtained utilizing metals with low electronegativities, such as Al or Pb. The ideality…
Abstract Different extraction techniques were applied to the fractionation of isotactic polypropylene. In solvent gradient extraction experiments two different solvent/non‐solvent systems were studied. Investigation of the fractions obtained by GPC, DSC and FTIR indicated that the fractionation proceeded according to…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and Characterization of Copper(II) Complexes of New Tripodal Polyimidazole LigandsShan Chen, John F. Richardson, and Robert M. BuchananCite this: Inorg. Chem. 1994, 33, 11, 2376–2382Publication Date (Print):May 1, 1994Publication History Published online1 May 2002P…
Abstract Small angle X‐ray scattering (SAXS) and rheology are employed to study the microphase separation transition in a symmetric poly(styrene‐ b ‐isoprene) diblock copolymer. The order‐disorder transition temperature T ODT has been identified with a good precision ( T ODT =359 K) and the interaction parameter is ex…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFluorescence activation and surface-state reactions of size-quantized cadmium sulfide particles in Langmuir-Blodgett filmsYongchi Tian, Changjun Wu, and Janos H. FendlerCite this: J. Phys. Chem. 1994, 98, 18, 4913–4918Publication Date (Print):May 1, 1994Publication History P…
Nanocrystalline silicon thin films with a grain diameter from three to seven nanometers were fabricated on silicon substrates. It is demonstrated for the first time that the thin films show intense violet and blue luminescence at room temperature. The luminescence spectra include three peaks at wavelengths of 415 nm,…
Normal mode analysis (NMA) is applied in a molecular-dynamics simulation of liquid CS2, modeled with a potential including internal degrees of freedom. The entire supercooled liquid range, from the glass transition at 100 K to melting at 165 K, and the normal liquid from 165 to 293 K, are studied at P=1 atm. The norma…
Cylindrical buttuohead specimens of an advanced silicon nitride were tested in uniaxial tension at temperatures between 1422 and 1673 K. In the range 1477 to 1673 K, creep deformation was reliably measured using high‐temperature contact probe extensometry. Extensive scanning and transmission electron microscopy has re…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRedox Properties of Porphycenes and Metalloporphycenes. A Comparison with PorphyrinsC. Bernard, J. P. Gisselbrecht, M. Gross, E. Vogel, and M. LausmannCite this: Inorg. Chem. 1994, 33, 11, 2393–2401Publication Date (Print):May 1, 1994Publication History Published online1 May…
The gain of Pr/sup 3+/-doped ZBLAN fibre amplifiers is hindered by a poor quantum efficiency due mainly to a high rate of multiphonon decay. Sulphide-based glasses ameliorate this problem through a higher radiative rate and lower nonradiative rate. In this letter, Pr/sup 3+/-doped Ga:La:S glass has been evaluated spec…