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61.
62.
Simpson HJ Collis JM Soukup RJ Collins MD Siegmann WL 《The Journal of the Acoustical Society of America》2011,130(5):2681-2686
A series of laboratory experiments was conducted to obtain high-quality data for acoustic propagation in shallow water waveguides with sloping elastic bottoms. Accurate modeling of transmission loss in these waveguides can be performed with the variable rotated parabolic equation method. Results from an earlier experiment with a flat or sloped slab of polyvinyl chloride (PVC) demonstrated the necessity of accounting for elasticity in the bottom and the ability of the model to produce benchmark-quality agreement with experimental data [J. M. Collis et al., J. Acoust. Soc. Am. 122, 1987-1993 (2007)]. This paper presents results of a second experiment, using two PVC slabs joined at an angle to create a waveguide with variable bottom slope. Acoustic transmissions over the 100-300 kHz band were received on synthetic horizontal arrays for two source positions. The PVC slabs were oriented to produce three different simulated waveguides: flat bottom followed by downslope, upslope followed by flat bottom, and upslope followed by downslope. Parabolic equation solutions for treating variable slopes are benchmarked against the data. 相似文献
63.
Olga Šolcov Pavel Topka Karel Soukup Květuše Jirátová Helena Váňová František Kaštánek 《Chemical Papers》2014,68(9):1279-1282
Combined thermal desorption and catalytic oxidation for soil decontamination was studied at the pilot plant scale. Gasoline, xylene, and 2-methylnaphthalene were used as model contaminants in the concentrations from 2 g to 10 g per kg of soil. To guarantee the flow of the exhaust gas from the thermal desorption unit into the catalytic oxidation unit, a Venturi pump was used. Based on the laboratory scale catalytic tests, the commercial catalyst EnviCat® VOC-1544 was employed in the catalytic oxidation. Residual concentrations of hydrocarbons in soil after the thermal desorption were below the detection limits of the applied analytical method (GC-MS). Although the contaminant concentrations at the inlet of the catalytic reactor significantly varied during the experiments, the efficiency of catalytic oxidation was higher than 90 % in all cases. 相似文献
64.
65.
In this paper we give a partial answer to a question of J. D. Monk on the size of independent families in product of interval algebras and for some related questions.The first author was supported by the United States Israel Binational Science Foundation, Publication 370The second author was supported by the Hungarian National Foundation for Scientific Research grant No. 1908 相似文献
66.
Milan Soukup Beat Wipf Erich Hochuli Hans G. W. Leuenberger 《Helvetica chimica acta》1987,70(1):232-236
An Enantionselective Synthesis of L-Threonine An enantioselective synthesis of L-threonine ( 1 ) is described. Racemic ethyl 2-acetamido-3-oxobutyrate ( 6 ) was synthesized from ethyl acetoacetate ( 2 ) [4][5] and then transformed to the epimeric optically active alcohols 7a and 7b by microbiological reduction with Saccharomyces rouxii. The Mixture 7a/7b could be converted to 1 by slightly modified, known Methods in a yield of ca. 52% with respect to 7a/7b . 相似文献
67.
The structural and electronic transport properties of La1−x
Ce
x
MnO3 (x=0.0–1.0) have been studied. All the samples exhibit orthorhombic crystal symmetry and the unit cell volume decreases with
Ce doping. They also make a metal-insulator transition (MIT) and transition temperature increases with increase in Ce concentration
up to 50% doping. The system La0.5Ce0.5MnO3 also exhibits MIT instead of charge-ordered state as observed in the hole doped systems of the same composition. 相似文献
68.
The construction and principle of operation of small-angle light scattering apparatus for studies of supermolecular structure in thin polymer films is described. The apparatus can be used to study changes in spherulite structure during crystallization and changes in films subjected to steady or sinusoidal strain. Typical results with polyethylene films are given. 相似文献
69.
The theoretical backgrounds of the method of spherulite size distribution determination, on the basis of the small-angle light scattering technique, are presented. Special corrections of experimental data are introduced to achieve great accuracy of the determination of scattered light intensity distribution. Experiments have been done on low-density polyethylene samples obtained in various crystallization conditions. For these samples, the stepwise distributions of spherulite size have been determined. 相似文献
70.
Dániel Tamás Soukup 《Topology and its Applications》2011,158(10):1219-1225
We introduce a general method to construct 0-dimensional, scattered T2 spaces which are not linearly D. The construction is used to show that there are aD, non-D-spaces, answering a question of Arhangel?skii. The latter example is achieved using Shelah?s club guessing principles. 相似文献