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1.
The sulphur K-edge x-ray absorption spectra of SO2 multilayer and of SO2 submonolayer adsorbed on Cu(100) are analysed. It is found that the dominant spectral features are of a molecular origin. The results support earlier findings that the SO2 molecule stands perpendicular to the surface. Use of non-selfconsistent potentials does not lead to a good quantitative agreement between theory and experiment. 相似文献
2.
Juray De Wilde Denis Constales Geraldine J. Heynderickx Guy B. Marin 《International Journal of Multiphase Flow》2007
The propagation speeds of linear waves in gas–solid suspensions depend strongly on the solids volume fraction and the wave frequency. The latter is due to gas–solid momentum transfer and allows a simple test on filtered gas–solid momentum transfer models. Such models may predict linear wave propagation speeds different from those obtained with the non-filtered model at wave frequencies higher than the filter frequency, but not at wave frequencies lower than the filter frequency. 相似文献
3.
Investigations on Metal Catalysts. XXII. Chemisorption of Hydrogen on Pt? Ru and η-Al2O3 Supported Pt? Ru Catalysts Measurements of the H2 chemisorption by volumetric method were carried out on several series of Pt? Ru and η-Al2O3 supported Pt? Ru catalysts. Addition of Ru to Pt and vice versa effects a remarkable influence on the sorption behaviour of the starting samples. For mixtures of carrier-free catalysts and η-Al2O3 as well as Pt? Ru/η-Al2O3 catalysts a hydrogen-spillover effect was found. 相似文献
4.
Lisa M Wilde 《Analytica chimica acta》2003,479(1):77-85
Force mapping with the atomic force microscope (AFM) allows the simultaneous acquisition of topography and probe-sample interaction data. For example, AFM probes functionalised with an antigen can be employed to map the spatial distribution of recognition events on a substrate functionalised with its specific antibody. However, to date this method has been limited to the detection of single receptor-ligand species. Were the detection of multiple receptor-ligand interactions possible, force mapping would offer great scope as a sensitive tool for bioassay and screening applications. We have developed an immobilisation strategy, which allows two different molecular species (in this case human serum albumin and the β subunit of human chorionic gonadotropin) to be present simultaneously on an AFM probe. Single point force spectroscopy results have revealed the ability of such probes to discriminate between their corresponding recognition points (anti-HSA and anti-βhCG IgG antibodies). As a control, force measurements were re-recorded in the presence of the known antigen (free in solution) for each antibody species and a marked decrease in the frequency of specific interaction is observed. As an additional control interactions between anti-βhCG IgG and the multifunctional probe are taken in the presence of free βhCG (“true” antigen) and free HSA (“false” antigen). It is shown that measurements recorded in the presence of a non-related protein species results in no change in either the force observed or the frequency of specific interactions, further confirmation that the specificity of force observed is due to the separation of antibody-antigen complex. 相似文献
5.
P. Šimon Marta Fratričová P. Schwarzer H.-W. Wilde 《Journal of Thermal Analysis and Calorimetry》2006,84(3):679-692
Degradation
of poly(ester-urethanes), poly(ether-urethanes) and poly(acrylic-urethanes),
as a base for automotive paintings in interior applications, has been studied
by DSC. The samples were clearcoat and black-pigmented paints, unstabilized
and stabilized with HALS Tinuvin 292, UV absorber Tinuvin 1130 and antioxidant
Hostanox O3, exposed to weathering in Xenotest and in Arizona desert. From
the dependences of oxidation onset temperature on the heating rate, the kinetic
parameters enabling to calculate the oxidation induction time for a chosen
temperature have been obtained. From the values of oxidation induction time,
the protection factors of the additives and the residual stability of the
polymer after an ageing stress has been evaluated. It has been shown that
the equivalence between the two methods of weathering depends on the polymer
composition. A new criterion for the evaluation of synergism/antagonism of
additives in the stabilizing mixture has been proposed. 相似文献
6.
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8.
A number of polyfunctionalized cis-bicycio ¦3.3.0¦octanes have been synthesized starting from the tricyclic key intermediate which was obtained by the intramolecular cyclopropanation reaction of the diazo keto ester . Selected stereocontrolled transformations of using nucleophiles and electrophiles have been studied for the preparation of the title compounds. 相似文献
9.
New experimental time-of-flight distributions are reported for Li+-N2 and Li2-CO at two center-of-mass energies of about 8 and 16 eV and large scattering angles θlab ? 120°. The Li+-N2 spectra show two widely spaced maxima, whereas the Li+-CO spectra show two and sometimes three maxima. The results are consistent with the model of rotational rainbows, and have also been analyzed in terms of an impulsive model involving collisions with the individual atoms of the molecules with energy-dependent masses. Classical trajectories for a simple model potential reveal only small contributions from vibrational excitation. 相似文献
10.