In conventional absorption spectrometers, the range of accessible concentrations of analytes in aqueous solution is significantly limited by the dynamic range of the measurement system. Here we introduce the concept of multiscale spectroscopy allowing extending that range by orders of magnitude within one single device. The concept relies on using multiple light-sample interaction lengths, boosting the accessible concentration range by a particular extension factor. We experimentally implement our concept by a liquid core waveguide having multiple fiber ports side-wise attached to the waveguide, thus probing the light propagating inside the core at predefined distances from the input. This configuration provides three orders of magnitude of interaction length in one device. To verify the concept we exemplarily determine the concentrations of nitrate and of Rhodamine 6G in water, showing one hundred times improved measurement capabilities. The multiscale spectrometer uses the entire sample volume and allows the simultaneous measurement of fluorescence and attenuance. Due to its integrated design and the extended measurements capabilities, we anticipate application of our device in many application-relevant areas such as water quality analysis or environmental science. 相似文献
Excitation functions and isomeric ratios for184Re, from -induced reactions on181Ta and natural W have been measured using the stacked-foil method. The data are compared with the theoretical predictions provided by the equilibrium and pre-equilibrium reaction model; for this propose we used the code INDEX development by ERNST. 相似文献
Zusammenfassung Ein Verfahren wird beschrieben, das die quantitative Bestimmung der Chenodesoxycholsäure-Konjugate in Gegenwart der entsprechenden Desoxycholsäure-Konjugate durch Reaktion mit Äthylacetat-Schwefels aure-Essigsäureanhydrid ermöglicht.
Summary A method is described for the quantitative determination of chenodesoxycholic acid conjugates in presence of related desoxycholic acid conjugates through reaction with ethyl acetate-sulfuric acid-acetic anhydride.
Résumé On décrit un procédé qui permet le dosage des conjugués de l'acide chénodésoxycholique en présence des conjugués analogues de l'acide désoxycholique par réaction avec le systéme acétate d'éthyle-acide sulfurique-anhydride acétique.
Common gaseous fuels are mixtures of several components. As the properties of the fuels can vary with the composition, but combustion needs to be stable, reliable analytical methods are highly sought after. Raman spectroscopic methods have proved their suitability for the characterization of diverse gaseous mixtures. They have the potential to overcome existing limitations of established technologies, since they are fast, non-consumptive, and accurate. Here, we demonstrate a gas sensor based on fiber-enhanced Raman spectroscopy (FERS) for fuel gas monitoring. Online detection of all gas components, including alkanes, carbon dioxide (CO2), nitrogen (N2), and hydrogen sulfide (H2S), for varying concentration ranges from tens of vol% down to the ppm level enables a comprehensive characterization of the fuels. The developed sensor system features a pinhole assembly which sufficiently reduces the background signal from the fiber to enable the detection of C2–C4 alkanes occurring in low concentrations. Detection limits in the low ppm region were achieved for the minor components of fuel gases, which allow the online monitoring of necessary purification steps, e.g., for biogas. The obtained results indicate that fiber-enhanced Raman sensors have the potential for comprehensive online and onsite gas sensing for fuel gas quality control.
A forced impact oscillator is coupled to a second freely moving oscillator with no amplitude constraint. The influence of the coupling strength and the external frequency is studied in detail. For intermediate coupling strength many of the long-period or chaotic motions are suppressed and replaced by short-period motions at least for not too high frequencies. Phase space trajectories are discussed for some characteristic examples. 相似文献
We have measured the muon momentum in pion decay at rest using a magnetic spectrometer. From the result, pμ+ = (29.787±0.005) MeV/c, we deduce a squared muon neutrino mass of (0.23±0.54) MeV2/c4. 相似文献