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61.
Summary Analysis of reported data on the swelling and deformation of polymer networks shows that the volume-dependent term in the deformational free energy cannot be neglected. The analysis is based on a comparison between the equilibrium modulof networks prepared at various dilutions and of the same degree of swelling and on a comparison between concentration dependences of the interaction parameter for a linear and a crosslinked polymer. 相似文献
62.
63.
A new type of L system is introduced in which each rule has a “delay”, a word over some alphabet, associated with it. This results in a new characterization of the etol languages, which only partially carries over to the eol languages. 相似文献
64.
Ermittlung der Löslichkeit für Kohlenstoff und das Ausscheidungsverhalten von Karbiden in Eisen-Kohlenstoff-Legierungen mit rd. 18% Cr in Abhängigkeit vom Nickelgehalt bis zu rd. 40% durch Aufkohlungsversuche in Wasserstoff-Methan-Gemischen bei Temperaturen zwischen 900 und 1200°C. Auswertung der Versuchsergebnisse für Aktivitäts- und Löslichkeitsberechnungen. Röntgenographische Untersuchungen der isolierten Karbide. 相似文献
65.
Summary The base catalyzed reaction between epoxide and carboxyl groups was studied using a simple model system phenylglycidyl ether-caproic acid in the presence of triethylamine. The reaction was investigated by mass spectrometry and GPC which provide an overall qualitative and quantitative survey of all the forming reaction products. The addition esterification is followed by etherification and condensation esterification and the main reaction product, monoester, is disproportionated yielding diester and diol. In a polyfunctional system, the latter reaction may cause splitting of the polymer chain and formation of new crosslinks. 相似文献
66.
Jiří Pinkas Ivana Císařová Ana Conde Rosa Fandos Michal Horáček Jiří Kubišta Karel Mach 《Inorganic chemistry communications》2009,12(1):11-14
Thermolysis of [TiMe2(η5-C5Me4Ph)2] (4) at 145 °C for 5 h afforded the singly tucked-in paramagnetic titanocene [Ti(III)(η5-C5Me4Ph){η5:η1-C5Me3Ph(CH2)}] (9). In distinction to the singly tucked-in permethyltitanocene [Ti(III)(η5-C5Me5){η5:η1-C5Me4(CH2)}] (1) which was found crystallographically disordered [J.M. Fischer, W.E. Piers, V.G. Young, Jr., Organometallics 15 (1996) 2410] the single crystal X-ray diffraction analysis of 9 afforded molecular parameters with nearly by one order better precision as measured by esd-values. 相似文献
67.
Development of antibodies with broad specificity recognition for sulfonamide drugs was found to be surprisingly difficult when conventional immunochemical strategies were applied to hapten design. To improve the cross-reactivity pattern of antibodies for the family of sulfonamide drugs, a novel strategy based on the single-ring (fragment-derived) hapten moieties with different spacer substituent lengths was employed for the preparation of immunogens, coating conjugates, and enzyme competitors. The rabbit antibodies raised against a common (one-ring) p-aminobenzenesulfonamide hapten moiety (attached to a carrier protein through the N-1 position) in combination with a homologous hapten-peroxidase tracer allowed the detection of 15 sulfonamide species at the maximum residue limit level using direct ELISA. The two-ring 6-(4-aminobenzensulfonylamino)hexanoic hapten mimics, previously reported in the literature as a weak generic antigen, generated surprisingly superior immune responses in rabbits. The antibodies raised against this two-ring hapten were capable of detecting at least 19 and 17 sulfonamides in a direct ELISA system at the regulatory level with sensitivities corresponding to 20 and 50% binding inhibition, respectively. A negligible cross-reaction with N4 metabolites makes it possible to measure responses of parent sulfonamides in the presence of their metabolized forms. In skimmed milk, the highest limit of detection (LOD) for sulfacetamide defined as 20% inhibition was 65.2 microg x L(-1) (IC20 value), whereas the additional 18 sulfonamides tested exhibited LODs in the range of 0.2-36.8 microg x L(-1). This sensitivity allows simple multisulfonamide tests to be established for use in the laboratory or on site. 相似文献
68.
Karel Král 《Microelectronics Journal》2008,39(3-4):375-377
Using a simplified model approach we estimate the optical line shape of the transition lines observable in photoluminescence experiments on quantum dots. We use the theory based on the interaction of electrons with the longitudinal optical phonons only. This theory gives, in the self-consistent Born approximation, the lowest-energy excited state line shape in the form of a very narrow peak with a shoulder on the low-energy side. We turn the attention to a comparison with experiments which appear to support this theoretical conclusion. This agreement emphasizes the role of the electronic multiple scattering on optical phonons in quantum dots. It is demonstrated that the optical line shape can give an information about the quantum dot system. 相似文献
69.
Katarina Drdlikova Karel Maca Martin Slama Daniel Drdlik 《Journal of the American Ceramic Society》2019,102(12):7137-7144
The study is focused on an optimization of the slip-casting process used for the fabrication of the transparent/translucent alumina ceramics; more precisely, on specifying the most appropriate way to stabilize the cast alumina suspensions. An innovative method of the particles’ stabilization by plasma treatment was compared with the classical electrostatic and the most frequently used electrosteric approach. Properties of green bodies (pore size distribution, density) and sintered samples (density, mean grain size, real in-line transmittance) were measured in term to evaluate the impact of the individual stabilization mechanism on the final properties of the transparent/translucent ceramics. The results showed that all tested approaches enable the preparation of the transparent/translucent alumina ceramics by Hot Isostatic Pressing. Ceramics prepared from the plasma treated as well as the electrostatically stabilized powders exhibited narrower pore size distribution, higher density, and lower mean grain size in comparison to ceramics fabricated from only electrosterically stabilized powders. Despite these promising properties the plasma-treated samples resulted in an unexpectedly low RIT of 36% caused by the presence of thin cracks. However, the electrostatically stabilized samples achieved the highest RIT value of 57%. 相似文献
70.
Lucie Čechovská Karel Cejpek Michael Konečný Jan Velíšek 《European Food Research and Technology》2011,233(3):367-376
Despite available reports on phenolic composition and antioxidant capacity (AOC) of fresh plums and prunes, there is a scarcity
of published knowledge on the antioxidants formed and/or released during the drying process in the literature. To evaluate
the compounds participating in reducing capacity of prunes, we compared aqueous and methanol extracts of fresh plums, commercial
prunes and home-made prunes prepared at different drying temperatures using an HPLC method with amperometric detection (HPLC-ECD).
The prunes dried at high temperature (90 °C, 18 h) in kitchen or laboratory oven with restricted ventilation gave up to 3.3 times
higher electrochemical capacity (EC) than fresh plums (dry matter; P. domestica cv. Domestica) in dependence on production protocol. Drying at 60 °C (low-temperature drying) for 18 h did not change the
EC significantly. Yet, lower EC was found in commercial tenderized prunes with sorbate; they were by a factor of 1.1–8.2 lower
in EC than the prepared low-temperature prunes. The principle responsible for the increase in EC in the prunes prepared at
high temperatures is 2,3-dihydro-3,5-dihydroxy-6-methyl-(4H)-pyran-4-one (DDMP). It was not detected until 74 °C was set during isothermal 18 h drying or until 6 h of drying passed
at 90oC drying. The ultimate acceptable dwell-time for the preparation of conveniently eatable prunes dried at 90oC under
the conditions used was assessed to 12 h. The EC of plums and prunes as well as the role of DDMP was confirmed by the use
of several methods for the assessment of AOC-DPPH• assay, β-carotene bleaching method, Oxipres test and Schaal oven test. 相似文献