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111.
Ulmer S Blaum K Kracke H Mooser A Quint W Rodegheri CC Walz J 《Physical review letters》2011,107(10):103002
A measurement scheme for the direct determination of the free cyclotron frequency ν(c) of a single particle stored in a Penning trap is described. The method is based on the dressed states of mode coupling. In this novel measurement scheme both radial modes of the single trapped particle are simultaneously coupled to the axial oscillation mode. 相似文献
112.
Control in anaerobic wastewater treatment plants is difficult to achieve but necessary due to a high sensitivity to disturbances and process complexity. With the help of different mathematical tools, control strategies can be developed. Particularly, a well-defined mathematical model can be highly effective for design, assessment and optimization of treatment plants. However, applications directly in the control system of a treatment plant are hard to achieve due to model complexity and usually require specialized software and the engagement of experts in the subject. The objective of the present study was the development of less empirical methods for assessment and control of a decentralized anaerobic plant for the treatment of domestic wastewater. A lab-scale plant, which consisted of a two-stage anaerobic digestion process followed by an anaerobic ammonium oxidation (ANAMMOX) reactor for nitrogen removal, was used as object of study. Ordinary differential equation models were implemented to simulate the processes that took place in the treatment plant. With the help of the implemented models, control tools were developed. These tools include a standalone application for monitoring of the two-stage anaerobic digestion process and an ammonium estimator for the ANAMMOX reactor by means of artificial neural networks (ANNs). The procedures followed aimed to reduce the amount of experimental work required so they can be easily transferred from laboratory to full-scale conditions. (© 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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The phosphide telluride Ti2PTe2 can be synthesised from the elements or from oxides in a thermite type reaction. Both ways have been optimised by consideration of the thermodynamic behaviour of the compound. Hence, the investigation of phase equilibria in the ternary system Ti/P/Te and of the thermal decomposition of Ti2PTe2 was necessary. This investigation was performed by using different experimental approaches as total pressure measurements, thermal analysis and mass spectrometry. The results were supported and further analysed by thermodynamic modelling of the ternary system. It was shown that Ti2PTe2(s) decomposes to Ti2P(s) and Te2(g) in six consecutive steps. The growth of single crystals of Ti2PTe2 is thermodynamically described as a chemical vapour transport with TiCl4(g) acting as the transport agent. 相似文献
115.
In this paper we determine the universal deformation rings of certain modular representations of finite groups which belong
to cyclic blocks. The representations we consider are those for which every endomorphism is stably equivalent to multiplication
by a scalar. We then apply our results to study the counterparts for universal deformation rings of conjectures about embedding
problems in Galois theory.
Received July 19, 1999 / Revised May 13, 2000 / Published online October 30, 2000 相似文献
116.
Frauke Baß mann-Schnitzler Jean-Marie S quaris 《Colloids and surfaces. A, Physicochemical and engineering aspects》2005,260(1-3):119-128
Amphiphilic natural organic matter (NOM) in soil, water and sediments plays an important role in the fate of low-soluble hydrophobic organic compounds (HOC) in the environment. Scaling NOM structural factors, which affect the transport and immobilization of HOC, is rather involved due to the complexity of the NOM materials. Sorption properties of hydrophobically modified polyacrylic (HMPA) polymers as NOM model substances for pyrene were investigated and discussed with regard to reported NOM results. Emission fluorescence spectroscopic properties of pyrene and potentiometric titrations were used to characterize the hydrophobic and acidic properties of HMPA samples. Excitation fluorescence spectroscopy allowed a speciation of pyrene molecules. Overall complexation constants β1 and β2 of pyrene with hydrophobic moieties (–C8H17) and (–C16H33) were calculated depending on the pH and electrolyte cation nature at an ionic strength of 10 mM, typical of soil solution conditions. Aggregation of HMPA molecules was detected by photon correlation spectroscopy. Normalized sorption constant Koc values for pyrene with HMPA samples similar to reported values with NOM support recent observations on the contribution of aliphatic moieties to the binding of polyaromatic hydrocarbons (PAH). The HMPA samples also model the partitioning behavior of hydrophobic micelle-like structures of NOM. 相似文献
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Guido M. Kukuk Dariusch R. Hadizadeh Jürgen Gieseke Marcus von Falkenhausen Ingrid B?hm Renate Semrau Horst Urbach Arne Koscielny Frauke Verrel Kai Wilhelm Hans H. Schild Winfried A. Willinek 《Magnetic resonance imaging》2010,28(9):1311-1318
PurposeTo present the feasibility of highly undersampled contrast-enhanced MRA (CE-MRA) of the supraaortic arteries with a 16-channel neurovascular coil at 3.0 T using parallel imaging in two directions with parallel imaging factors (PIF) up to 16.Materials and MethodsInstitutional review board approval and informed consent were obtained. In a prospective study, MRA protocols including PIF of 1, 2, 4, 9 and 16 yielding a spatial resolution from 0.81×0.81×1.0 mm3 to 0.46×.46×0.98 mm3 were acquired. In 32 examinations, image quality and vascular segments were rated independently by two radiologists. SNR estimations were performed for all MRA protocols.ResultsThe use of high PIF allowed to shorten acquisition time from 2:09 min down to 1:13 min and to increase the anatomic coverage while maintaining or even increasing spatial resolution down to 0.46×0.46×0.98 mm3. The larger anatomic coverage that was achieved with the use of high PIF allowed for visualization of vascular structures that were not covered by the standard protocols. Despite the resulting lower SNR using high PIF, image quality was constantly rated to be adequate for diagnosis or better in all cases.ConclusionThe use of high PIF yielded diagnostic image quality and allowed to increase the anatomic coverage while maintaining or even improving spatial resolution and shortening the acquisition time. 相似文献
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