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Since the discovery of the hydrated electron in bulk water in 1962, the species has been the subject of intense research and speculation. For many decades even the basic features of the simplest of all chemical and biological transients and reactants--such as its structure, binding motifs, lifetimes, and binding energies--remained elusive. Recently, another milestone in the research of the hydrated electron was the determination of its vertical binding energy (VBE). Also a long-lived hydrated electron near the surface of liquid water has been discovered. The present Minireview discusses the implications and consequences of this and other new findings in addition to the emerging complex picture of a solvated electron in water. 相似文献
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Ole E. Barndorff-Nielsen Neil Shephard Matthias Winkel 《Stochastic Processes and their Applications》2006
In this paper we provide a systematic study of how the probability limit and central limit theorem for realised multipower variation changes when we add finite activity and infinite activity jump processes to an underlying Brownian semimartingale. 相似文献
75.
The objective of the study is an analysis of lung ventilation during breathing under rest conditions and for high frequency
ventilation (HFV). The measurements include investigations of the flow using an endotracheal tube. A transparent model of
the upper human lung airways down to the 6th generation was generated, and the oscillatory flow through the branching network
was studied by DPIV. The method of refractive index matching of the fluid (water/glycerin) and the model (silicone) allows
an unobstructed view into the internal flow network. The mass flow rate and the frequency were adapted to the characteristic
flow parameters, the Reynolds- and the Womersley-number. The comparison of the results for normal breathing and HFV shows
that a mass exchange occurs for higher frequencies known as Pendelluft, which could not be seen during normal breathing. This
mass exchange between the daughter tubes is a consequence of the asymmetric impedance in the successive daughter branches.
The lung topology determines the local pressure loss in the model and therefore the local mass flow direction of the Pendelluft.
At higher frequencies we observed an increase in exchange between the daughter branches. The transformation of the velocity
profiles between inspiration and expiration suggests a net mass flow which is created into the model along the centerline
and the inner walls of the bifurcations. This flow is compensated with a net mass outflow to the trachea along the outer walls
of the branches. 相似文献
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Schütz K Persike M Carle R Schieber A 《Analytical and bioanalytical chemistry》2006,384(7-8):1511-1517
The anthocyanin pattern of artichoke heads (Cynara scolymus L.) has been investigated by high-performance liquid chromatography–electrospray ionization mass spectrometry. For this purpose a suitable extraction and liquid chromatographic method was developed. Besides the main anthocyanins—cyanidin 3,5-diglucoside, cyanidin 3-glucoside, cyanidin 3,5-malonyldiglucoside, cyanidin 3-(3′′-malonyl)glucoside, and cyanidin 3-(6′′-malonyl)glucoside—several minor compounds were identified. Among these, two peonidin derivatives and one delphinidin derivative were characterized on the basis of their fragmentation patterns. To the best of our knowledge this is the first report on anthocyanins in artichoke heads consisting of aglycones other than those of cyanidin. Quantification of individual compounds was performed by external calibration. Cyanidin 3-(6′′-malonyl)glucoside was found to be the major anthocyanin in all the samples analyzed. Total anthocyanin content ranged from 8.4 to 1,705.4 mg kg−1 dry mass.
相似文献