Composites for high temperatures
Abstract
Materials Literature
文献浏览
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。
Controlled roughening of poly(ethylene terephthalate) by photoablation : study of wetting and contact angle hysteresis
The smooth surface of crystalline poly(ethylene terephthalate) films is readily roughened by ablative photodecomposition obtained by absorption of the pulsed far-UV radiation of the excimer laser. The amplitude of this roughness (of the order of 1 μm) is controlled by the intensity of the pulsed radiation and by the n…
Diaminopropionate ammonia-lyase from Salmonella typhimurium. Purification and characterization of the crystalline enzyme, and sequence determination of the pyridoxal 5'-phosphate binding peptide.
We have found a wide occurrence of alpha,beta-diaminopropionate ammonia-lyase in bacteria and actinomycetes. Considerable amounts of this enzyme were found in Salmonella typhimurium. The enzyme was purified and crystallized from S. typhimurium (IFO 12529). The relative molecular mass of the native enzyme, estimated by…
An iron–organic polymeric smoke suppressant for poly(vinyl chloride)
Abstract The incorporation of a poly[ferrocene‐1, 2 (1, 3: 1, 1′)diylmethylene] fraction with M̄ n =2100 as a smoke suppressant additive into both unplasticized and di(2‐ethylhexyl)phthalate‐plasticized, calcium carbonate‐filled poly(vinyl chloride) (PVC) compositions entails appreciable reductions in smoke evolution…
Calculation of forces on magnetised ferrous cores using the Maxwell stress method
The authors examine the problems involved in the application of the Maxwell stress equations for finite-element force calculations on magnetised ferrous cores. They also study the effect of the tangential magnetic field strength H/sub t/ on the accuracy of the force calculation. An effective H/sub t/ value is presente…
Effect of Arrangements of Reinforcements on Mechanical Properties of Ferrocement
First Name is required invalid characters Last Name is required invalid characters Email Address is required Invalid Email Address Invalid Email Address
Observation of a re-entrant isotropic phase in a pure disc-like liquid crystal
We report the observation of an optically isotropic phase in the new disc-like mesogen 2,3,7,8,12,13-hexa(octadecanoyloxy)truxene. On cooling, this optically isotropic phase goes over into a nematic phase, while on heating a columnar phase grows in. To our knowledge this is the first example of a pure discotic mesogen…
Mechanisms of chemical undoping of conducting polymers by ammonia
The chemical compensation of p-type conducting polymers by ammonia gas can occur by several mechanisms, which lead to products of very different quality.
On the structure of macroreticular styrene‐divinylbenzene copolymers
Abstract The influence of the removal of various diluents, pore forming agents from the porous styrene‐ethylstyrene‐acrylonitrile‐divinylbenzene copolymers on the structure of the matrix was investigated by several methods. The most advantageous pathway to preserve the initial structural edifice of the porous networks…
The crystal structures, magnetic and electrical properties of two polymeric chlorocuprate(II) compounds
The crystal structures of piperidinium trichlorocuprate(II)[Hpip][CuCl3], and piperazinium hexachlorodicuprate(II), [H2pipz][Cu2Cl6], have been determined by X-ray diffraction techniques. [Hpip][CuCl3] is monoclinic, space group C2/c, with a= 18.385(7), b= 8.439(4), c= 11.878(5)Å, and β= 103.63(5)° while [H2pipz][Cu2C…
Hydrophilic microporous polyurethane versus expanded PTFE grafts as substitutes in the carotid arteries of dogs. A limited study
A novel, microporous, hydrophilic polyether urethane-urea (PEUU) vascular graft was compared with expanded PTFE in the canine carotid artery. At implantation times ranging from 4 h to 6 months, all the PEUU grafts were found to be occluded while of the PTFE grafts, only those implanted for 1 week and 6 months were blo…
A better scalar Preisach algorithm
A Preisach hysteresis model for the case in which Everett's function, E(H/sub 1/, H/sub 2/), has been defined from measurements of the magnetization change from a turning point H/sub 1/ to the field H/sub 2/. E(H/sub 1/, H/sub 2/) is the integral of the Preisach density function, whose symmetry imposes the relation E(…
Spectroscopic investigation of the interaction of Co2(CO)8 with MgO and SiO2
Co2(CO)8, when absorbed in the gas phase, in vacuo, on fully dehydrated MgO, forms a variety of carbonyl clusters both neutral and ionic. These clusters disintegrate into monometallic species upon dosing with either CO or NH3, resulting in Co(CO)–4 and Co2+(CO)n(n= 2 or 3) with CO and Co(CO)–4 and Co2+(NH3)6 with NH3,…
Double-Axis Rotary Shadowing for High-Resolution Scanning Electron Microscopy
Thin continuous metal coatings and a scanning electron microscope-generated spot size in the range of the visualized particles, are necessary prerequisites if one hopes to extract high-resolution topographic information in the scanning electron microscope. Chemical fixation and dehydration in organic solvents at room…
Electrochemical characteristics of LaNi5 system hydrogen-absorbing alloys as negative electrode materials for nickel-hydrogen batteries.
LaNi5 のような水素吸蔵合金を負極材料として使用するニッケル-水素電池を開発する上での解決もすべき問題点の一つは合金負極の高温域における容量低下である。本研究では, このような温度特性の改善を自的として, LaNi5 の Ni を Cu, Cr, Mn あるいは Al で部分置換した一連の合金を取り上げ,置換金属の種類と負極電位の関係ならびに放電容量の温度およびセル内圧依存性を平衡水素圧の点から検討した。その結果, LaNi5 の N iを Cu, Cr, Mn あるいは Al で部分置換するとこの順に平衡水素圧が低下するが, 同時に負極の平衡電位 (開路電位) が貴側に移動し, 電池電圧の低下をもたらすことが明らかとなった。…
Schwingfestigkeitssteigerung durch Festwalzen
Abstract Das Festwalzen weist nunmehr eine fast 60jährige Tradition auf und ist heute insbesondere in der Automobilindustrie fester Bestandteil zahlreicher Fertigungsprozesse. An der Entwicklung des Verfahrens hatte das Institut für Werkstoffkunde der TH Darmstadt großen Anteil. Nach einem kurzen historischen Rückblic…
Galvanic Corrosion Caused by Corrosion Products
Experiments were conducted to quantify the magnitude of galvanic currents and potentials that exist between metals (iron, copper, titanium, aluminum, chromium, and nickel) and their corrosion products in oxygen-containing environments. Current measurements using a zero resistance ammeter and potential measurements of…
Increase of aqueous humor proteins with aging.
Quantitative analyses by crossed immunoelectrophoresis were carried out on 31 eyes of 26 cataract patients, age 4-80 years, to detect age changes in the human aqueous humor especially in the following aqueous humor proteins: prealbumin, albumin, alpha 1-acid glycoprotein and transferrin. There was a significant correl…
A study of the mechanical anisotropy of high‐draw, low‐draw, and voided PVDF
Abstract The mechanical anisotropy of oriented PVDF sheet is examined using a variety of experimental techniques. The mechanical behavior is similar to that observed previously for low‐density polyethylene and nylon and consistent with a parallel lamellar crystalline structure. The s 31 compliance is reduced in magnit…
Tautomerism in free base porphyrins: the porphyrin potential energy surface
AM1 calculations are reported which demonstrate that the classical hydrogen migration in porphyrin occurs via a two-step mechanism, not a synchronous-concerted mechanism as has been previously supposed; the implications of this mechanism on tautomerization dynamics are discussed.