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181.
Wilfried Carl 《Macromolecular theory and simulations》1996,5(4):691-698
We calculated the first-order perturbation expansion of the mean-square end-to-end distance of polymers in three and four space dimensions. The segments of the chain were assumed to interact via a pair potential with a short-range repulsive and an additional attractive part. For a purely repulsive potential, the well-known results of the δ-function-pseudopotential approach are recovered, whereas the inclusion of an attractive part leads to a non-vanishing contribution even for a vanishing binary cluster integral. 相似文献
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Ortwin Brede Ralf Hermann Wilfried Helmstreit Thomas Taplick Ludwig Stephen 《Macromolecular Symposia》1988,18(1):113-121
By means of pulse radiolysis and laser photolysis experiments with detection by optical absorption spectroscopy short-living radical transients in pure PE and in PE doped with additives (e.g. di->tert-butyl-p-cresol, diphenylamine, benzophenone and carbon tetrachloride) were characterized by their optical absorption spectra and kinetics. It was found that the additive radicals were formed in a very fast process probably via exciton migration and subsequent energy transfer and dissociation reactions. 相似文献
184.
Olaf Schmidt Andr Fuchs Dietrich Gudat Martin Nieger Wilfried Hoffbauer Edgar Niecke Wolfgang W. Schoeller 《Angewandte Chemie (International ed. in English)》1998,37(7):949-952
The butadiene-like phosphanylcarbene 2 is, according to ab initio calculations, the intermediate in the conversion of 1 into 3 in the solid state [Eq. (a)]; it is only 1.3 kJ mol−1 higher in energy than 1 . For this conversion, only minor changes in the endocyclic bonds are required throughout the entire reaction. R2N=2,2,6,6-Me4C5H6N. 相似文献
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Nora Graf Eda Yegen Thomas Gross Andreas Lippitz Wilfried Weigel Simone Krakert Andreas Terfort Wolfgang E.S. Unger 《Surface science》2009,603(18):2849-2860
The chemical constitution of functionalized supports is an important parameter that determines their performance in a broad range of applications, e.g. for immobilization of biomolecules. Supports with amino functionalized surfaces are also often used for DNA microarray experiments. However, spectral data which have been reported for surfaces with amino functionalities suffer from some inconsistencies. In this article a detailed XPS (X-ray photoelectron spectroscopy) and NEXAFS (Near edge X-ray absorption fine structure) database for amino functionalized surfaces is presented. Amino-terminated surfaces prepared from aliphatic and aromatic aminosilanes or aminothiols and a field sample are considered. Effects of aging in air and damage by radiation are addressed as well. 相似文献