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21.
We will demonstrate in this paper that Raman scattering of visible light is a versatile tool both for research and industrial process monitoring of thin chalcopyrite films for solar cells. Thin films of Cu(In, Ga)(S,Se)2 (CIGSSe) are produced by rapid thermal processing of stacked elemental Cu-In-Ga-Se layers. The Raman investigations are accompanied by grazing incidence X-ray diffraction (GI-XRD) and X-ray florescence (XRF) measurements. GI-XRD measurements confirm that the films show a two-fold elemental gradient: a sulfur gradient from the top and a Ga gradient from the CIGSSe/Mo interface. By Rietveld refinement of the GI-XRD spectra of the surface-near (∼ 100nm) ratio of sulfur to selenium can be obtained which corresponds well to the intensity ratio of the two Raman A1 modes of CuInS2 and CuInSe2. The asymmetric line shape of both XRD diffractograms and Raman spectra is attributed to the sulfur gradient. In addition we show that the intensity ratio of the satellite Raman B and E modes shows a correlation with the Cu to In + Ga ratio obtained by XRF. 相似文献
22.
Maria Ferreira Fernanda A. R. Oliveira &Rolf Jost 《International Journal of Food Science & Technology》1999,34(1):27-32
Summary An attempt was made to reduce the microbial load of unpasteurized fresh egg white by using cross-flow microfiltration and a Tetra-Laval bactocatch installation. Cross-flow tangential microfiltration of liquid fresh egg white was not feasible as there was irreversible membrane clogging within a few minutes of operation. As membrane clogging could have been caused by ovomucin, this protein was removed from whole fresh egg white by increasing the salt strength and lowering the pH. Ovomucin-depleted egg white (ODEW) was successfully microfiltered on the same membrane. Compared to fresh egg white, ODEW had lower foaming and viscous properties, and these properties remained unchanged after bactofiltration. The reduction of microbial load was, however, relatively low. 相似文献
23.
H. W. Hahnemann A. Naumann J. C. Rotta O. Scholze J. W. Beck G. Pfotzer W. Jellinghaus H. Schuh J. Wiedemann M. Hempel H. Schwieger H. Wittmeyer G. Vogelpohl H. Roos Ch. Tönnies E. G. Niemann W. Zimmermann W. Jost P. Stottmann M. Paul D. Stockburger 《Forschung im Ingenieurwesen》1966,32(6):196-200
Ohne Zusammenfassung
VDI 相似文献
24.
1-Ethyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide (EMI-TFSI) is shown to reversibly permit lithium intercalation into standard TIMREX® SFG44 graphite when vinylene carbonate (VC) is used in small amounts as additive. The best performance was obtained when 5% of VC was added to a 1 M solution of LiPF6 in EMI-TFSI. Intercalation of lithium in the SFG44 graphite host was demonstrated over 100 cycles without noticeable capacity fading. The reversible charge capacity was around 350 mA h g−1 and an only small irreversible capacity loss per cycle could be observed. Li4Ti5O12 was used as counter electrode material. Scanning electron microscopy indicates the reduction of the electrolyte without graphite exfoliation in the neat electrolyte and the formation of a passivation film in the case of a VC-containing electrolyte. Other additives that were tested comprise ethylene sulphite and acrylonitrile which show also a positive effect, but a smaller one than vinylene carbonate. LiCoO2 positive electrodes were cycled in a 1 M solution of LiPF6 in EMI-TFSI with good charge capacity retention over more than 300 cycles, when Li4Ti5O12 was used as counter electrode. The formation of a passivation film is proven on the LiCoO2-electrodes, when the electrolyte contained VC, but not in the neat ionic liquid. Finally, the stable cycling of a full cell configuration is proven in this electrolyte system. An ammonium-containing ionic liquid (methyltrioctylammonium-bis(trifluoromethylsulfonyl)-imide, MTO-TFSI) is shown to permit the cycling of both, graphite and lithium cobalt oxide when VC is used as additive in small amounts, but at slightly elevated temperatures. 相似文献
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Anand Dersingh Ramiro Liscano Allan Jost John Finnson Rajiv Senthilnathan 《Mobile Networks and Applications》2010,15(2):267-282
Controlling access in pervasive environments is crucial and a significant challenge because users and devices can connect
from anywhere which results in users and resources becoming available at any point of time and location depending on the situation.
Access control policies for this type of environment are required to conform to high-level business notions. In pervasive
environments, these high-level notions refer to contexts of the situation which can change unpredictably and must be interpreted
semantically to maintain proper access control. Therefore, it is necessary to have a formal representation that represents
semantics of the contexts, reflects the change of the situation, and can be shared and understood by a policy system. This
paper addresses these issues by introducing a context management system that uses a semantic web approach as an underlying
mechanism to model and represent semantics of the contexts. The system stores current contexts in a semantic knowledge base
which is used by a semantic access control system in order to form access control policies and evaluate policies at run time.
The approach is validated through a proof of concept implementation that includes performance results of the context management
system as it responds to a change of the situation. 相似文献
28.
Goettert M Schattel V Koch P Merfort I Laufer S 《Chembiochem : a European journal of chemical biology》2010,11(18):2579-2588
A series of 42 naturally occurring flavonoids and one flavonoid glucuronide were tested for their ability to inhibit p38α mitogen-activated protein kinase (p38α) and c-Jun-N-terminal kinase 3 (JNK3). Potent inhibitors with IC(50) values in the low micromolar range were identified. Structure-activity relationships were evaluated and the most promising compounds were docked into the ATP binding site of these kinases. Among the different classes of flavonoids, the flavonol group showed better inhibition of p38α. Of this class, kaempferol-7,4'-dimethylether was a potent p38α inhibitor, displaying 13-fold selectivity for p38α over JNK3. The flavone compounds without a 6-methoxy group preferentially inhibited JNK3. The flavone glycoside, luteolin-7-O-glycoside, was identified as a potent inhibitor with the greatest selectivity toward JNK3. In contrast, the flavanol compounds displayed similar inhibitory activities toward both kinases. 相似文献
29.
A qualitative micromechanical fracture mechanics model is presented that shows how a structure that is sensitive to the presence of a single crack or hole can be rendered flaw tolerant by the presence of an interacting distribution of such flaws. The simple model was inspired by the ductile fracture experienced by the under-designed gusset plates recovered from the I-35W Bridge collapse and by the experimentally measured increase in toughness of concrete damaged by fire. 相似文献
30.
TJ Hobday PA Pellikka CH Attenhofer Jost JK Oh FA Miller JB Seward 《Canadian Metallurgical Quarterly》1998,82(11):1425-7, A9
Ninety-two consecutive patients with atrial fibrillation (AF) who underwent dobutamine stress echocardiography were compared with a control group of patients in sinus rhythm matched for age, sex, and resting heart rate. Patients with AF had an increased chronotropic response to dobutamine, but there were no adverse effects and no evidence that the lower doses of dobutamine typically given to patients with AF were insufficient to induce ischemia. 相似文献