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201.
We present experimental and theoretical data on the signal decay of recordings measured at various densities. In contrast to expectations, the signal decay does not generally increase with increasing linear density; rather, it peaks at a surprisingly low density. Using a nondestructive spin-stand technique, we determined the energy barrier as well as the anisotropy field distribution. These experimental data are used in a self-consistent recording model that accounts for thermal activation effects at writing as well as at storage. We found that the record process inevitably induces phase shifts in the recorded pattern that lead to the observed decay behavior 相似文献
202.
H. Richter 《Chemical and Petroleum Engineering》1997,33(4):445-451
203.
The Geometry Modelling System (GEMO), developed at Dresden University of Technology, covers the area of definition and manipulation of geometrical objects with regard to a further processing in a CAD/CAM system. The programming system GEMO has been designed modularly. The implemented algorithms are based on analytic and constructive geometrical methods. All modules have clearly defined interfaces, permitting a direct integration in CAD/CAM systems. Implementations for PCs and 32-bit computers are now available. 相似文献
204.
K. Haberland A. Bhattacharya M. Zorn M. Weyers J. -T. Zettler W. Richter 《Journal of Electronic Materials》2000,29(1):94-98
Using a specially-designed spectrometer enabling combined reflectance anisotropy spectroscopy (RAS) and reflectance measurements
on rotating substrates in a commercial MOVPE reactor, we report the first full-spectroscopic RAS-monitoring of (Al,Ga)InP-based
650 nm laser growth. First, a spectral database was built up from systematic studies of AlGaInP RAS signatures for different
Al compositions, doping levels and growth temperatures. These data are subsequently used for the interpretation of characteristic
RAS fingerprints taken throughout the entire laser growth process. From the analysis of characteristic changes in the RAS
spectra even small deviations from the optimum process (doping levels, composition, etc.) which would effect the performance
of the final device can be detected. 相似文献
205.
Richter Franz Bathras Bryce Barbetta Duarte Julia Gollner Michael J. 《Fire Technology》2022,58(4):2167-2188
Fire Technology - Fires occurring at the wildland-urban interface (WUI) have rapidly increased in frequency and severity over the past few decades. As a result of these extreme fires, multiple... 相似文献
206.
Fire Technology - Natural materials like wood are increasingly used in the construction industry, making the understanding of their ignition and burning behaviour in fires crucial. The state of the... 相似文献
207.
Karsten König Peter Andersen Tuan Le Hans Georg Breunig 《Microscopy research and technique》2015,78(12):1154-1158
Multiphoton laser scanning microscopy commonly relies on bulky and expensive femtosecond lasers. We integrated a novel minimal‐footprint Ti:sapphire oscillator, pumped by a frequency‐doubled distributed Bragg reflector tapered diode laser, into a clinical multiphoton tomograph and evaluated its imaging capability using different biological samples, i.e. cell monolayers, corneal tissue, and human skin. With the novel laser, the realization of very compact Ti:sapphire‐based systems for high‐quality multiphoton imaging at a significantly size and weight compared to current systems will become possible. Microsc. Res. Tech. 78:1154–1158, 2015. © 2015 Wiley Periodicals, Inc. 相似文献
208.
Johannes Richter Malte Stonis Jan Langner Thoms Blohm Bernd-Arno Behrens 《Production Engineering》2018,12(3-4):419-429
In this paper, the investigation of thin flash generation in precision forging process of an aluminum long flat part is described. The aim was to derive a predictive simulation method for thin flash generation in order to increase both process and part quality in the future. The forging processes were varied by use of different preforms with equal volumes but different mass distributions while using the same final part geometry. The experimentally forged parts were analyzed concerning the amount and part area of the generated thin flash. The conducted FE simulations were analyzed concerning the hydrostatic pressure values p in the part areas near to the tool gap between upper and lower die immediately before form-filling. For a more detailed comparison, single p values were included to hydrostatic pressure functions P. The comparison between the P functions and the experimentally determined thin flash height shows, that high pressure values as well as high gradients of the P functions indicate less thin flash generation. The method therefore allows a qualitative prediction of thin flash generation. It can provide two kind of information. First: The prediction of the specific locations where thin flash is likely to occur in one final part by use of one single preform. Second: The qualitative prediction of the specific final part areas were thin flash is likely to occur depending on different preform geometries. This method will decreases the necessity of time-consuming forging trials and can shorten the preform designing process in the future. 相似文献
209.
Andreas Vetter Finn S. Babbe Bernhard Hofbeck Peter Kubis Michael Richter Stephan J. Heise Jrg Ohland Ingo Riedel Christoph J. Brabec 《Progress in Photovoltaics: Research and Applications》2016,24(7):1001-1008
Local electric defects may result in considerable performance losses in solar cells. Infrared (IR) thermography is one important tool to detect these defects on photovoltaic modules. Qualitative interpretation of IR images has been carried out successfully, but quantitative interpretation has been hampered by the lack of “calibration” defects. The aims of this study are to (i) establish methods to induce well‐defined electric defects in thin‐film solar cells serving as “calibration” defects and to (ii) assess the accuracy of IR imaging methods by using these artificially induced defects. This approach paves the way for improving quality control methods based on imaging in photovoltaic. We created ohmic defects (“shunts”) by using a focused ion beam and weak diodes (“interface shunts”) by applying a femto‐second laser at rather low power on copper indium gallium selenide cells. The defects can be induced precisely and reproducibly, and the severity of the defects on the electrical performance can be well adjusted by focused ion beam/laser parameters. The successive assessment of the IR measurement (ILIT‐Voc) revealed that this method can predict the losses in Pmpp (maximal power extractable) with a mean error of below 10%. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
210.
Qing Yu Manfred Richter Landong Li Fanxiao Kong Guangjun Wu Naijia Guan 《Catalysis communications》2010,11(11):955-959
Selective catalytic reduction of NO by hydrogen was studied over Cr modified Pt/ZSM-35 catalysts. The preparation process greatly influenced catalytic activity and sample prepared by co-impregnation method exhibits the best activity. In situ DRIFT studies revealed that on Pt–Cr/ZSM-35, (1) new Pt-NOδ+ and NO species adsorbed on Pt were detected upon NO + O2 adsorption; (2) much more ammonia species were formed under reaction condition. Cr addition not only enhanced the adsorption of NOx but also promoted the formation of surface NH4+ species, which should be the origin of promotional effect of Cr on Pt/ZSM-35 for H2-SCR reaction. 相似文献