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Basic principles of the present optoelectronic research activities at Hoechst AG are presented in this contribution. Within the diversified broad band spectrum of optoelectronic materials and applications our interest is focused on new types of polymer optical fibers and nonlinear optical device principles using organic Langmuir–Blodgett films and electrically poled polymers. The basic principles and the limits of the present research and development activities which have a high market potential are outlined. 相似文献
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J. Boden T. Ehmann T. Groh I. Haumann K. Bächmann 《Fresenius' Journal of Analytical Chemistry》1994,348(8-9):572-575
For selective influencing of the ion mobility in CZE several electrolyte additives were used. With acetone as organic solvent the migration times of inorganic cations are changed. The separation of Cl– and I– is optimized by adding -cyclodextrin to the electrolyte. By adding 18-crown-6 it is possible to slow down the mobility of K+. In this way the disturbing effect of matrix ions can be prevented. 相似文献
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Matthias F. Groh Dr. Anna Isaeva Prof. Dr. Michael Ruck 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(35):10886-10891
Two polymorphs of the new cluster compound [Ru2Bi14Br4](AlCl4)4 have been synthesized from Bi24Ru3Br20 in the Lewis acidic ionic liquid [BMIM]Cl/AlCl3 ([BMIM]+: 1‐n‐butyl‐3‐methylimidazolium) at 140 °C. A large fragment of the precursor’s structure, namely the [(Bi8)Ru(Bi4Br4)Ru(Bi5)]5+ cluster, dissolved as a whole and transformed into a closely related symmetrical [(Bi5)Ru(Bi4Br4)Ru(Bi5)]4+ cluster through structural conversion of a coordinating Bi82+ to a Bi5+ polycation, while the remainder was left intact. Both modifications have monoclinic unit cells that comprise two formula units (α form: P21/n, a=982.8(2), b=1793.2(4), c=1472.0(3) pm, β=109.05(3)°; β form: P21/n, a=1163.8(2), b=1442.7(3), c=1500.7(3), β=97.73(3)°). The [Ru2Bi14Br4]4+ cluster can be regarded as a binuclear inorganic complex of two ruthenium(I) cations that are coordinated by terminal Bi5+ square pyramids and a central Bi4Br4 ring. The presence of a covalent Ru? Ru bond was established by molecular quantum chemical calculations utilizing real‐space bonding indicator ELI‐D. Structural similarity of the new and parent cluster suggests a structural reorganization or an exchange of the bismuth polycations as mechanisms of cluster formation. In this top‐down approach a complex‐structured unit formed at high temperature was made available for low‐temperature use. 相似文献
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We consider semigroups of operators on a W∗-algebra and prove, under appropriate assumptions, the existence of a Jacobs-DeLeeuw-Glicksberg type decomposition. This decomposition
splits the algebra into a “stable” and “reversible” part with respect to the semigroup and yields, among others, a structural
approach to the Perron-Frobenius spectral theory for completely positive operators on W∗-algebras. 相似文献
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Adrian A. Ammann Petra Macikova Ksenia J. Groh Kristin Schirmer Marc J. F. Suter 《Analytical and bioanalytical chemistry》2014,406(29):7653-7665
A targeted analytical method was established to determine a large number of chemicals known to interfere with the gluco- and mineralocorticoid signalling pathway. The analytes comprise 30 glucocorticoids and 9 mineralocorticoids. Ten out of these corticosteroids were primary metabolites. Additionally, 14 nonsteroids were included. These analytes represent a broader range of possible adverse modes of action than previously reported. For the simultaneous determination of these structurally diverse compounds, a single-step multimode solid-phase extraction and pre-concentration was applied. Extracts were separated by a short linear HPLC gradient (20 min) on a core shell RP column (2.7 μm particle size) and compounds identified and quantified by LC-MS/MS. The method provided excellent retention time reproducibility and detection limits in the low nanograms per litre range. Untreated hospital wastewater, wastewater treatment plant influent, treated effluent and river waters were analysed to demonstrate the applicability of the method. The results show that not all compounds were sufficiently eliminated by the wastewater treatment, resulting in the presence of several steroids (~20 ng/L) and nonsteroids in the final effluent, some of them at high concentrations up to 200 ng/L. Most of the detected mono-hydroxylated steroidal transformation products were found at significantly higher concentrations than their parent compounds. We therefore recommend to include these potentially bioactive metabolites in environmental toxicity assessment. 相似文献
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