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。
Knowledge of the thickness of sections is important for proper interpretation of electron micrographs. Therefore, the thicknesses of sections of n-butyl methacrylate polymer were determined by ellipsometry, and correlated with the color shown in reflected light. The results are: gray, thinner than 60 mmicro; silver, 6…
Abstract The phenomenon of insolubilization of rubber by carbon black has been known for at least twenty-seven years. There have been many attempts during this time to establish a relationship between insolubilization, or bound rubber formation, and reinforcement of rubber by carbon black. It was postulated, as far ba…
Fabrics in use are rarely subjected to extensions in only one direction, though fabric load-extension testing is normally done in this way. A two-dimensional tester has been constructed with which load-extension curves for both weft and warp directions (or any other mutually perpendicular directions) are recorded simu…
F?ur poly~vinyl chloride) polymers l?repared with different initiators were exposed to ultravIOlet radIant energy and to heat, III a vacuum and in air.The gaseous products evo!ved were analyzed by mass spectrometry.Changes in chemical structure were followed by Illfrared spectrophotometry.Benzene was among the product…
The magnetic anisotropy constant Cr 2 O 3 arising from the dipolar interactions among the chromic ions was calculated to be -0.059 cm -1 per ion at absolute zero, and the magnetic anisotropy constant due to the crystalline field combined with the spin-orbit coupling was estimated from the fine-structure coupling const…
The shape of the immiscibility volume in the system BaO‐B 2 O 3 ‐SiO 2 is determined from data on seventeen compositions. The ternary critical solution curve originates at the critical point in the binary system BaO‐B 2 O 3 , located at 1225°C. and 15 weight % BaO. It extends almost linearly to its terminus on the sil…
A detailed investigation is made of the general laws governing the increase of corrosion resistance of metallic systems by means of alloying. The role of local cells in alloy corrosion is considered briefly. Some attention is given also to the control characteristics of corrosion processes. Other topics discussed incl…
The optical density of a flame fusion single crystal plate of CaTiO3 is reported. The refractive indices for the visible region are given, with nD = 2.403±0.02. The results of dielectric constant and loss measurements over the temperature range from 90 to 430°K reveal no unusual behavior. A room-temperature dielectric…
The structure of KttSO 4 has been determined and refined in two projections. The two ttSO~-groups in the asymmetric unit are differently linked by hydrogen bridges: one set forms 'dimers' across a symmetry centre; the other is linked into infinite chains along a glide plane. All hydrogen bridges are approximately alon…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSeparation of Orthohydrogen from Parahydrogen and of Paradeuterium from Orthodeuterium by Preferential AdsorptionClarence M. Cunningham, Douglas S. Chapin, and Herrick L. JohnstonCite this: J. Am. Chem. Soc. 1958, 80, 10, 2382–2384Publication Date (Print):May 1, 1958Publicat…
A statistical theory of the excluded volume effect in a polymer molecule is developed, making use of a pearl necklace model with a continuous medium approximation. For the mean square end-to-end distance 〈R2〉 and the mean square radius of gyration 〈S2〉, the theory leads to the same expressions as Zimm, Stockmayer, and…
Specific Volume and Degree of Crystallinity of Semicrystalline Poly (chlorotrifluoroethylene), and Estimated Specific Volumes of
Occasionally an electron paramagnetic resonance absorption line is accompanied by satellite lines which result from a weak magnetic dipole-dipole interaction coupling the electron spin to a neighboring nuclear spin. The satellites correspond to a change in spin state of the neighbor nucleus concurrent with the change…
Abstract Berichtet wird von den Anfängen der Fluorchemie und der ersten Darstellung von Polytetrafluoräthylen und Polytrifluorchloräthylen. Die strategische Bedeutung und die Kombination von Eigenschaften lassen erkennen, daß besonders Polytetrafluoräthylen ein unentbehrliches Hilfsmittel in vielen Industriezweigen wi…
Abstract Corrosion tests have been carried out on lead totally immersed in solutions of organic acids (0·1–0·0001 N). The corrosion rates in acetic, propionic, butyric, succinic, and lactic acids of the same normality were very similar, while pyruvic acid appeared to form a protective film. Inter‐crystalline attack wa…
T he behavior of an infi nitely long flexib le fil a men t after transverse impact is treated theoret.icall y. The fil a ment is ass u med to have a tension-strain curve that is always co ncave dow nward, and to have no short-ti me creep or stress-rei fixation effects. Under most cond itions the impact in itiates a va…
During recent yea rs a co nsid erable nurnber of t heo retical a nd exp erimental stud ies have been published o n t he kin etics and mechanism of t he t hermal d eco mposition of poly mers. The tr eatment of depo. lymerization as a free-rad ical chain reaction involv ing t he four basic steps of initiation, p ropagat…
Abstract Melt viscosities of styrene homopolymers and copolymers with 1.5 to 23 mole‐% methacrylic acid were measured with a parallel plate plastometer. Apparent viscosities were found to drop off sharply with increasing rate of shear in the range 10 −4 to 10 −1 sec. −1 . An increasing concentration of carboxyl groups…
Abstract Silicon nitride has been prepared by heating pure silicon in purified nitrogen at 1450°. X ‐ray studies showed the presence of two nitrides, and a method was therefore devised to separate them. Although these nitrides differ in their crystal structure, they have the same compositions, corresponding to Si3N4.…
The crystal structure of the low-temperature form of sodium triphosphate, Na~P3010, Phase II, has been determined by Fourier methods. The unit cell is monoelinic with [a] -----16.00, [b] ----5-24, [c] --~ II.25 A, fl --93 . The space group is C2/c and the unit cell contains 4 units of NasP3010. The triphosphate ions h…