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61.
Herle V Fischer P Windhab EJ 《Langmuir : the ACS journal of surfaces and colloids》2005,21(20):9051-9057
An equimolar mixture of a cationic surfactant, cetylperidinium chloride (CPyCl), and salt sodium salicylate (NaSal) forms wormlike micelles in aqueous solutions. Under shear, the solution shows a pronounced shear-thickening behavior, which is coupled with oscillations in shear rate and the apparent viscosity. In this shear-thickening regime shear bands form, which also oscillate in position and intensity. These shear bands are visualized by direct imaging and Rheo-small angle light scattering methods. Temporal intensity fluctuations of the shear bands were evaluated using image analysis. Fourier transformations (FT) of the oscillating shear rate and intensity of the shear bands showed a single dominating frequency in the power spectrum analysis. This characteristic frequency as well as the amplitude of shear rate fluctuation was found to increase with stress. From the rheological and optical measurements, we propose that a stress driven mechanism is responsible for the formation of shear bands. Experiments performed in transparent parallel-plate geometry show dampening of the shear rate oscillations and increase in the characteristic frequency with decrease in the gap. Power spectrum analysis and the SALS measurements confirm the formation of different structures as a function of gap size in the parallel-plate geometry. 相似文献
62.
Erich Ziegler Hans Junek Hildegrad Kroboth 《Monatshefte für Chemie / Chemical Monthly》1976,14(1):317-324
Thermolysis ofMeldrum acid in the presence of cycloalkanones leads to dioxaspiro-alkanediones (3 a–c) by the elimination of acetone. With increasing temperature an additional dehydratation is observed and with two moles ofMeldrum acid pyrano-cycloalkano-pyranediones (6 a–b) are formed. The reaction of dialkylMeldrum acids with cyclic 1,3-diones is investigated. 相似文献
63.
Daniel Krois Mario Simonetti Erich Wünsch 《Monatshefte für Chemie / Chemical Monthly》1989,120(11):1029-1041
Summary For the identification of a protein predicted by DNA sequence analysis of the TTV1 virus from the archaebacteriumThermoproteus tenax, the trieicosapeptide H-Thr-Pro-Thr-Pro-Thr-Pro-Thr-Tyr-Asp-Ile-Thr-Tyr-Val-Val-Phe-Asp-Val-Thr-Pro-Ser-Pro-Thr-Pro-OH, corresponding to the protein fragment 79–101, was prepared by conventional methods of peptide synthesis. This sequence portion may possibly represent a suitable protein specific immunepitope.
Zur Hypothese eines TTV1 Virus/Thermoproteus tenax F154-Proteins. Teil II: Synthese des Protein-fragments 79–101
Zusammenfassung Für den Nachweis der Expression des Proteins F154 — nach einer Sequenzanalyse des Genoms des TTV1 Virus im ArchaebakteriumThermoproteus tenax postuliert — wurde das Peptid H-Thr-Pro-Thr-Pro-Thr-Pro-Thr-Tyr-Asp-Ile-Thr-Tyr-Val-Val-Phe-Asp-Val-Thr-Pro-Ser-Pro-Thr-Pro-OH (Proteinfragment 79–101) mit Hilfe konventioneller Peptidsynthese hergestellt. Diese Peptidsequenz sollte ein geeignetes proteinspezifisches Immunepitop darstellen.相似文献
64.
65.
Jinsong Zhang Chris Taylor Erich Bowman Leo Savage-Low Michael W. Lodewyk Larry Hanne Guang Wu 《Tetrahedron letters》2013
A process for synthesizing 1,4-benzodioxin, through oxidation of a phenol to an o-quinone followed by treatment with an enamine, has been developed. Adduct stereochemistry is found to be retained via this one-pot reaction. The method uses hypervalent iodine reagent under mild conditions and is compatible with a wide scope of phenols and enamines. 相似文献
66.
A magnetic balance was used for measuring the susceptibility of metals and alloys, in an atmosphere of purified argon, up to 1800°c. Comparison of the susceptibilities of liquid Fe, Co and Ni gives information on the liquid state. The changes in the susceptibilities of Ge, Sn and Te on melting are typical of semi-metallic elements and semiconductors, but their behaviour differs according to the degree of symmetry in the solid state. 相似文献
67.
68.
Coupled Hartree-Fock theory is used to compute and map the current density induced in planar hydrocarbons by an external magnetic field. Results of useful accuracy can be obtained with modest (6-31G**) basis sets by employing a continuous gauge transformation. Maps are presented and discussed for benzene, naphthalene, anthracene, tetracene, pentacene, heptacene, and biphenylene. © 1996 John Wiley & Sons, Inc. 相似文献
69.
The anionic polymerization of butadiene, to both the 1,2- and 1,4-addition products, is an important industrial process. It is known that the reaction can be steered to either the 1,2- or 1,4-product by the addition, or absence, of a complexing solvent such as ether. The goals of the current study were to map the MNDO Potential Energy Surfaces (PES) of the propagation reactions both in the presence and absence of dimethyl ether to gain insight into the factors influencing the reaction's selectivity. Single point ab initio calculations at the DZP level were run on all reactants, products and transition states as a cross check on the MNDO results. 相似文献
70.
Erich Zobetz 《Crystal Research and Technology》1994,29(3):379-385
A new theorem on homometric polytypes is presented. Examples of homometric close-packed structures and MX2-polytypes are given. The method derived may be used to construct homometric n-tuplets by means of decomposition procedures. 相似文献