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21.
We studied the electrical and optical properties, density, and crystalline structure of Au nanostructures prepared by direct
current sputtering on glass. We measured temperature dependence of sheet resistance and current-voltage characteristics and
also performed scanning electron microscopy [SEM] analysis of gold nanolayers. It was shown that within the wide range of
temperatures, gold nanolayers (<10 nm) exhibit both metal and semiconducting-like type of conductivity. UV/Vis analysis proved
the semiconducting characteristic of intrinsic Au clusters. SEM analysis showed the initiatory stadium of gold layer formation
to be running over isolated islands. Gold density calculated from the weight and effective thickness of the layers is an increasing
function of the layer thickness up to approximately 100 nm. In thin layers deposited on solid surface, a lattice expansion
is observed, which is manifested in the increase of the lattice parameter and the decrease of metal density. With increasing
layer thickness, the lattice parameter and the density approach the bulk values. 相似文献
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Kristýna Hladká Zdeňka Randulová Bohuslava Tremlová Petr Ponížil Pavel Mančík Michaela Černíková František Buňka 《LWT》2014
The aim of this work was to compare selected properties (hardness, cohesiveness, adhesiveness, characteristics of fat globules, pH, meltability and sensory characteristics – homogeneity, rigidity and flavour) of processed cheeses (dry matter content 40 g/100 g; fat in dry matter content 50 g/100 g) made with traditional emulsifying salts (sodium salts of phosphates) and products in which the traditional emulsifying salts were replaced with 1 g/100 g κ-carrageenan. The development of the above-mentioned properties was studied in dependence on the maturity level of cheese (raw material; 1–16 weeks' maturity). The samples made without the use of traditional emulsifying salts were nearly five times as hard as the products with phosphates regardless of the maturity level of cheese. In both types of samples, hardness was decreasing and adhesiveness was rising with the increasing maturity level of cheese. Meltability of the samples without traditional emulsifying salts was very low and remained practically unchanged with the increasing maturity level of cheese. On the other hand, in the processed cheeses with phosphates, meltability was increasing with the rising maturity level of cheese. 相似文献
24.
Michaela Petrášová Bohuslava Tremlová Zdeňka Javůrková 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2016,33(8):1283-1289
In this study we developed an immunofluorescence method to detect pea protein in meat products. Pea protein has a high nutritional value but in sensitive individuals it may be responsible for causing allergic reactions. We produced model meat products with various additions of pea protein and flour; the detection limit (LOD) of the method for pea flour was 0.5% addition, and for pea protein it was 0.001% addition. The repeatabilities and reproducibilities for samples both positive and negative for pea protein were all 100%. In a blind test with model products and commercial samples, there was no statistically significant difference (p > 0.05) between the declared concentrations of pea protein and flour and the immunofluorescence method results. Sensitivity was 1.06 and specificity was 1.00. These results show that the immunofluorescence method is suitable for the detection of pea protein in meat products. 相似文献
25.
C,N-chelated dicyclopentadienylzirconium complexes and their possible use as hydrogenation catalysts
Josef Bareš Zdeňka Padělková Philippe Meunier Nadine Pirio Didier Poinsot Aleš Růžička 《Inorganic chemistry communications》2010,13(12):1512-1514
In situ generated Cp2Zr(n-Bu)Cl (6) reacts with {2-[(CH3)2NCH2]C6H4}2Pb to form exclusively {2-[(CH3)2NCH2]C6H4}Cp2ZrCl (7), [(CH3)2NCH2]C6H5, butene and elemental lead. The further derivatization of chloride (7) to fluoride (8), hydride (9), methyl derivative (10), and a reduction of 7 are also described. The crystal structures of 7–10 were determined. The catalytic activity of 9 and 10 in hydrogenation of styrene was also preliminarily tested. 相似文献
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Alena Randová Lidmila Bartovská Štěpán Hovorka Magda Poloncarzová Zdeňka Kolská Pavel Izák 《应用聚合物科学杂志》2009,111(4):1745-1750
The anisotropic swelling of Nafion 112 membrane in pure organic liquids was monitored by an optical method. The findings were used as a basis for application of the group contribution method to the relative expansion in equilibrium. From a total of 38 organic liquids under study, 26 were selected as an evaluational set from which the group and structural group contributions were assigned. The remaining 12 compounds were used as the testing set. Value of ±1.5% in relative expansions was determined to be the experimental error. Maximum differences between the experimental and calculated relative expansions in both sets did not exceed the value of ±3%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
28.
Lurcher mutant mice represent a natural model of genetically‐determined olivocerebellar degeneration caused by a mutation in the δ2 glutamate receptor gene. They suffer from progressive postnatal loss of cerebellar Purkinje cells and a decrease of granule cells and inferior olive neurons. Their wild type littermates serve as healthy controls. A confocal laser scanning microscope was used aiming investigation the dynamics of changes in the cerebellar cortex of Lurcher and wild type mice derived from two strains during the period of 8–21 postnatal days. Fluorescent double‐staining was used to visualize mainly the Purkinje cells in cerebellar slices. In wild types, only normal Purkinje cells of round or regular drop‐shaped were present, when staining intensity of other individual cell structures differed in dependence on the age of the animal. In Lurcher mutants, there were still some normal‐shaped cells. Nevertheless, depending on the animal's age, a wide variety of stages of the cell degeneration were depicted. The main characteristics of Purkinje cell degeneration in the early stage are: disruption of the continuity of the Purkinje cell layer, dark spots in cell nuclei and an irregular coloring of the cytoplasm. Later, the cells and their nuclei were deformed, often with two main dendrites sprouting from the cell body. Finally, the cell and nucleus margins were unclear, dendrites were significantly thickened, showing signs of shrinkage and fragmentation. Cell nucleoli underwent changes in number and appearance. No differences between the Lurcher mice of both strains (C3H and B6CBA) under examination were found. Microsc. Res. Tech. 76:545–551, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
29.
Summary Swelling and mechanical behavior of negatively (ionic comonomer-sodium methacrylate) and positively (ionic comonomer-(2-acrylamidoethyl)trimethyl
ammonium chloride) charged networks of poly(N-isopropylmethacrylamide) (PIPMAm) and poly(N-isopropylacrylamide) (PIPAAm) was investigated in water/ethanol mixtures at room temperature. Strong cononsolvency effect
was observed for uncharged and negatively charged gels of both systems; while for neat solvents high degree of swelling Q was observed, for solvent mixtures pronounced minima in swelling were found. Swelling minima are connected with the coil-to-globule
transition of network chains and their characteristic parameters-concentration of ethanol at the minimum, ceth,m, and corresponding swelling degree, Qm, were determined. With increasing amount of negatively charged ionic comonomer the minimum in swelling shifts to higher ceth,m values and Qm increase. On the other hand, positively charged networks of both systems exhibit roughly constant Q values practically independent of solvent mixtures compositions. For all four systems it was found that mechanical behavior
is predominantly determined by the degree of swelling regardless of charge concentration. 相似文献
30.
Soňa?HermanováEmail author Monica?M.?Moya Cabrera Zdeňka?Vyroubalová Lucy?Vojtová 《Polymer Bulletin》2011,67(9):1751-1760
Novel triazole-based aluminum complex {O,O′-[4,5-P(O)Ph2tz]-AlMe2 was studied as the catalyst for the ring-opening polymerization of caprolactone (ε-CL) in chlorobenzene. In the presence
of methanol, isopropanol, and bifunctional poly(ethylene glycol), the catalytic system produced polymers with high conversion
(81–85 %) but broader distribution (M
w/M
n = 1.5–1.8). The system of catalyst and benzyl alcohol produced relative monodisperse PCLs (M
w/M
n ~ 1.2) with defined molecular weight at 1/1ratio, 60 °C and an initial concentration of ε-CL equal to 0.5 mol/L. 相似文献