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861.
Kenan Elibol Clemens Mangler Tushar Gupta Georg Zagler Dominik Eder Jannik C. Meyer Jani Kotakoski Bernhard C. Bayer 《Advanced functional materials》2020,30(34)
Many applications of 2D materials require deposition of non‐2D metals and metal‐oxides onto the 2D materials. Little is however known about the mechanisms of such non‐2D/2D interfacing, particularly at the atomic scale. Here, atomically resolved scanning transmission electron microscopy (STEM) is used to follow the entire physical vapor deposition (PVD) cycle of application‐relevant non‐2D In/In2O3 nanostructures on graphene. First, a “quasi‐in‐situ” approach with indium being in situ evaporated onto graphene in oxygen‐/water‐free ultra‐high‐vacuum (UHV) is employed, followed by STEM imaging without vacuum break and then repeated controlled ambient air exposures and reloading into STEM. This allows stepwise monitoring of the oxidation of specific In particles toward In2O3 on graphene. This is then compared with conventional, scalable ex situ In PVD onto graphene in high vacuum (HV) with significant residual oxygen/water traces. The data shows that the process pathway difference of oxygen/water feeding between UHV/ambient and HV fabrication drastically impacts not only non‐2D In/In2O3 phase evolution but also In2O3/graphene out‐of‐plane texture and in‐plane rotational van‐der‐Waals epitaxy. Since non‐2D/2D heterostructures' properties are intimately linked to their structure and since influences like oxygen/water traces are often hard to control in scalable fabrication, this is a key finding for non‐2D/2D integration process design. 相似文献
862.
Fuze Jiang Wenbo Ju Zhengyuan Pan Luchan Lin Yang Yue Yi‐Bo Zhao Congju Li Frank Clemens Corsin Battaglia Jing Wang 《Advanced Electronic Materials》2020,6(2)
Electro‐conductive nanofiber networks have potential applications as gas diffusion electrodes (GDEs) operating at solid–liquid–gas three‐phase interfaces. Flexible GDEs are developed, based on a versatile method of conformally coating a Cu layer on membranes consisting of stacked electrospun nonconductive polymer nanofibers. The Cu coating, comprising fine‐grained Cu crystals, has an average thickness of circa 50 nm and a root‐mean‐square roughness of circa 5.3 nm, maintaining the topography of polymer nanofibers. For nanofiber membranes with a thickness ranging in a few micrometers, the conformal Cu layer coats all nanofibers in the outermost layers as well as in the bulk of the membrane. All demonstrated Cu‐coated nanofiber networks have sheet resistance <2.4 Ω◽, and gas permeability in the order of 10−13 to 10−15 m2, which are comparable to some commercialized carbon based micro‐/nanofiber GDEs. Particularly, these conductive nanofiber networks have excellent bending durability, with negligible conductivity degradation after 10 000 bending test cycles. The high conductivity, gas permeability, and flexibility of these 3D nanofiber networks allow for applications as GDEs into various flexible electrochemical devices. 相似文献
863.
Stefan Schoder Klaus Roppert Michael Weitz Clemens Junger Manfred Kaltenbacher 《International journal for numerical methods in engineering》2020,121(9):2051-2067
In low Mach number aeroacoustics, the known disparity of length scales makes it possible to apply well-suited simulation models using different meshes for flow and acoustics. The workflow of these hybrid methodologies include performing an unsteady flow simulation, computing the acoustic sources, and simulating the acoustic field. Therefore, hybrid methods seek for robust and flexible procedures, providing a conservative mesh to mesh interpolation of the sources while ensuring high computational efficiency. We propose a highly specialized radial basis function interpolation for the challenges during hybrid simulations. First, the computationally efficient local radial basis function interpolation in conjunction with a connectivity-based neighbor search technique is presented. Second, we discuss the computation of spatial derivatives based on radial basis functions. These derivatives are computed in a local-global approach, using a Gaussian kernel on local point stencils. Third, radial basis function interpolation and derivatives are used to compute complex aeroacoustic source terms. These ingredients are necessary to provide flexible source term calculations that robustly connect flow and acoustics. Finally, the capabilities of the presented approach are shown in a numerical experiment with a co-rotating vortex pair. 相似文献
864.
Susann Zahn Clemens Otto Harald Rohm 《International Journal of Food Science & Technology》2020,55(2):769-775
The cleanability of food contact materials is, among others, determined by the physico-chemical properties of the soiling material. In the current study, starch of different origin was gelatinised and partially hydrolysed with diastase. The degree of hydrolysis was determined as the reducing capacity in terms of dextrose equivalents, and by the changes in apparent viscosity and surface tension. After spreading the starch paste on electropolished stainless steel coupons and subsequent drying, the removal was studied with a laboratory flow cell. These cleaning tests revealed a higher cleaning effectivity for smaller dextrins, which can be attributed to corresponding changes in solubility. Furthermore, the addition of commercially available diastase to demineralised water increased the cleaning effectivity of starch and dextrin soils at 25 °C. The results indicate that smaller starch breakdown products require reduced energy for removal so that cleaning processes can be adequately adjusted. 相似文献
865.
Serial 1H-MRS in relapsing-remitting multiple sclerosis: effects of interferon-beta therapy on absolute metabolite concentrations 总被引：2，自引：0，他引：2
Schubert F Seifert F Elster C Link A Walzel M Mientus S Haas J Rinneberg H 《Magma (New York, N.Y.)》2002,14(3):213-222
To assess the applicability of magnetic resonance spectroscopy (MRS) for long-term follow-up of neurological diseases a longitudinal
1H-MRS study at 3 T was carried out on ten patients having relapsing-remitting multiple sclerosis (MS) who, after baseline
examination, received interferon-β (IFN) lb. At 8–20 examinations within up to 34 months absolute concentrations ofN-acetylaspartate (NAA), total creatine (tG), and choline-containing compounds (tCho) were determined in a large non-enhancing
lesion and contralateral normal appearing white matter (NAWM). MR spectra were analyzed using a novel time domain-frequency
domain method including non-parametric background characterization. For comparison at baseline, ten healthy controls were
examined. The concentrations of tCho and tCr were found to be higher in MS brain than in control brain. Besides a non-significantly
lower NAA concentration in lesions there were no concentration differences between lesions and NAWM. Over the follow-up period
the measured metabolite concentrations exhibited a high variability. Most concentrations remained within this scatter, and
statistical tests revealed significant fluctuations in the levels of metabolites in one case only. This stability of the metabolite
concentrations over time might result from IFN therapy as for the spontaneous course of relapsing-remitting MS decreasing
metabolite (NAA/tCr) ratios have been reported. The results further suggest that future treatment trials intending to use
metabolite concentrations as a secondary outcome indicator use even longer observation periods and, besides group analysis
of large cohorts, investigate the time behavior of selected single cases. The biochemical abnormalities found in NAWM emphasize
the importance of analyzing both lesion and NAWM. 相似文献
866.
Pellicciari R Filosa R Fulco MC Marinozzi M Macchiarulo A Novak C Natalini B Hermit MB Nielsen S Sager TN Stensbøl TB Thomsen C 《ChemMedChem》2006,1(3):358-365
The first series of 2'-substituted 2-(3'-carboxybicyclo[1.1.1]pentyl)glycine derivatives, (2R)- and (2S)-(2',2'-dichloro-3'-carboxybicyclo[1.1.1]pentyl)glycine (10) and (11), and 2-(2'-chloro-3'-carboxybicyclo[1.1.1]pentyl)glycine (12) were synthesized and evaluated as mGluR ligands. Compounds 11 and 12 were shown to be competitive group I mGluR antagonists. These results are also discussed in light of docking studies with both the active (closed) and inactive (open) conformations of mGluR1. 相似文献
867.
Klein Joachim Baier Christel Chrszon Philipp Daum Marcus Dubslaff Clemens Klüppelholz Sascha Märcker Steffen Müller David 《International Journal on Software Tools for Technology Transfer (STTT)》2018,20(2):179-194
International Journal on Software Tools for Technology Transfer - The popular model checker PRISM has been successfully used for the modeling and analysis of complex probabilistic systems. As one... 相似文献
868.
Isabel S. Muranyi Clemens Otto Claudia Pickardt Raffael Osen Peter Koehler Ute Schweiggert‐Weisz 《Journal of food science》2016,81(11):C2656-C2663
The technofunctional properties of 2 protein isolates from Lupinus angustifolius L. Vitabor isolated by different procedures were investigated. The lupin protein isolate prepared by aqueous alkaline extraction with subsequent isoelectric precipitation (ILP) showed a significantly higher degree of protein denaturation and lower denaturation temperatures than the one obtained by aqueous salt‐induced extraction followed by dilutive precipitation (MLP) as determined by differential scanning calorimetry. Rheological investigations revealed higher firmness and a viscoelastic solid‐like behavior of ILP, in contrast to MLP that showed viscoelastic, liquid‐like properties. Protein solubility of MLP was higher compared to ILP and solubility minima were slightly different for both lupin protein isolates. The protein isolates exhibited different technofunctional properties with ILP showing higher water binding capacity, lower oil binding capacity and lower emulsifying capacity than MLP. This reflects the different putative application of both lupin protein isolates as food ingredients, for example for ILP as a moisture enhancer and for MLP as a “natural” emulsifier in mixed food systems. 相似文献
869.
Clemens Döring Mario Jekle Thomas Becker 《Critical reviews in food science and nutrition》2016,56(6):999-1011
Arabinoxylan (AX) is the major nonstarch polysaccharide contained in various types of grains. AX consists of a backbone of β1.4D-xylopyranosyl residues with randomly linked αlarabinofuranosyl units. Once isolated and included as food additive, AX affects foodstuff attributes and has positive effects on human health. AX can be classified into waterextractable and waterunextractable AX. For isolating AX out of their natural matrix, a range of methods was developed, adapted, and improved. This review presents a survey of the commonly used extraction methods for AX by the influence of different techniques. It also provides a brief overview of the structural and technological impact of AX as a dough additive. A concluding section summarizes different detection methods for analyzing and quantification AX. 相似文献
870.