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961.
Ursula Bentrup Jörg Radnik Udo Armbruster Andreas Martin Jork Leiterer Franziska Emmerling Angelika Brückner 《Topics in Catalysis》2009,52(10):1350-1359
A new setup is presented which enables simultaneous wide- and small-angle X-ray scattering (WAXS/SAXS) and Raman spectroscopic
experiments during the synthesis of Mo-based mixed oxide catalyst precursors at the μ-spot beamline at the Berliner Elektronenspeicherring-Gesellschaft
für Synchrotronstrahlung (BESSY). Furthermore, we report about the separate monitoring of the same reactions under comparable
conditions by simultaneous combined ATR/UV–vis/Raman spectroscopic measurements. For testing the performance of both experimental
setups two syntheses were described comprising the precipitation of metal molybdates by mixing solutions of metal nitrates
and ammonium heptamolybdate. Additionally, the effect of H3PO4 admixture on precipitation was investigated. The combined evaluation of spectroscopic and WAXS/SAXS data allows the discrimination
between different molybdate species appearing in solution and precipitate. Furthermore, these molybdate species could be assigned
to separate phases of different crystallinity. 相似文献
962.
963.
964.
Micro gear pump with internal electromagnetic drive 总被引:1,自引:0,他引:1
This paper presents the concept, design and fabrication of a gear pump based on recently introduced synchronous micro motors as an integrated driving system. The micro motor is fully integrated in the fluidic system consisting of the inlet, outlet and pump chamber. A preliminary test on the gear pump flow rate is successfully reported. The whole system is mainly realized by means of micro fabrication technologies like UV-depth lithography and copper electroplating. Polymer magnets with alternating axial magnetization were applied in the toothed rotors. The use of polymer magnets affords a miniaturization with maximum space filling and without limitation in shape. In first tests the temperature behavior and the functional capability were investigated. 相似文献
965.
Andreas Zendler 《Empirical Software Engineering》2001,6(2):161-180
The investigation of software engineering techniques by using the experiment sets up the discipline of experimental software engineering. The effectiveness and efficiency of software engineering techniques have been studied in experiments and confronted with empirical data. The results of these experiments are published in a diversity of journals and proceeding papers. However, there is not an overview so far which represents the available results systematically. By taking the results from published experiments that deal with analysis, design, implementation, test, maintenance, quality assurance, and reuse techniques a preliminary software engineering theory is developed. From this theory, fruitful problems, suggestions for gathering new data, and entirely new lines of investigation are deduced. 相似文献
966.
967.
v. Berg v. Braunschweig Griesche Nüsslein Rieck und Stahl 《Zeitschrift für Jagdwissenschaft》1973,19(1):57-64
Ohne Zusammenfassung 相似文献
968.
Ohne Zusammenfassung 相似文献
969.
In several termite species, distinct differences in the composition of cuticular hydrocarbons among colonies correspond to
high genetic divergence of mitochondrial DNA sequences. These observations suggest that hydrocarbon phenotypes represent cryptic
species. Different cuticular hydrocarbon phenotypes also are found among colonies of fungus-growing termites of the genus
Macrotermes. To determine if these hydrocarbon differences in Macrotermes also indicate cryptic species, we sequenced the mitochondrial CO I gene from species in West and East Africa. Among individuals
of a supposed species but belonging to different cuticular hydrocarbon phenotypes, the genetic distances are much smaller
than distances between species. Unlike what has been observed in other termites, Macrotermes hydrocarbon phenotypes do not represent cryptic species. Our findings suggest fundamental differences in the evolution and/or
function of cuticular hydrocarbons among different termite lineages.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
970.
Kristina Lachmann Sebastian Eckert Alfred Vogel Antje Klinger Andreas Gebert Claus-Peter Klages 《Progress in Organic Coatings》2009,64(2-3):294-299
The aim of our research is to develop a novel surface coating for the use in laser microdissection and laser pressure catapulting (LMPC). LMPC is a contact- and contamination-free technique to separate histologic material and living cells for further proteomic and genomic analysis. Several physico-chemical functions must be included within the optimum coating system designed for this purpose, like optical absorption at the laser wavelength, combined with optical transparency in the visible region, a control of the laser ablation process, mechanical stability and biocompability for the adhesion of the histologic material.To achieve the optimum system the combination of several layers is required. The optical absorbance to capture the radiation energy from a frequency-tripled Nd:YAG laser (λ = 355 nm) is reached by a thin layer of zinc oxide (ZnO), deposited by hollow cathode gas flow sputtering. The laser ablation process is controlled by a polyelectrolyte multilayer, consisting of poly(diallyldimethylammonium chloride) (PDADMAC) and poly(sodium 4-styrenesulfonate) (PSS). The evaporation of chemisorbed water from the film is used to promote the catapulting process. For the mechanically stable, laser-dissectible layer organic coatings, like photoresists or lacquers, are suitable. Silica-containing polyacrylate nanocomposites were employed for this purpose.The investigation of the coating system included LMPC experiments with varying compositions of the layer system. The best results were obtained using a system consisting of ZnO, a polyelectrolyte multilayer deposited from 0.1 M Na2SO4 containing polymer solutions, and a 1.5-μm thick layer of the polyacrylate nanocomposite.To check the quality of the developed system, experiments with the commonly used poly(ethylene naphthalate) (PEN) foil were performed simultaneously. In addition to the determination of the parameters required for LMPC, quantitative real-time Polymerase Chain Reaction (rt-PCR) of the dissected material verified the benefit of the new system. 相似文献