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91.
Norbert Koubek 《e & i Elektrotechnik und Informationstechnik》2002,119(3):a26
Firmen&;ProdukteNeuer 16-ZOLL-LCD-Monitor
Der Schlanke mit der gro?en Bildfl?che 相似文献92.
Jungwirth M Pöcksteiner N Kovacs G Weigel R 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2002,49(4):519-527
Using the planar waveguide concept in surface acoustic wave (SAW) technology is often advantageous when the modeling of transversely distributed phenomena is indispensable for an accurate design of SAW devices. This is especially true when complex multi-track structures such as transversely coupled resonator filters (TCRFs) are under consideration where, e.g., transverse velocity and stiffness profiles have to be incorporated in the device simulation. The interdigital transducers (IDTs) and the reflector gratings composing those devices behave as planar waveguides, supporting, in principle, all kinds of modes such as bound, semi-bound, and radiation modes. Therefore, to model these SAW propagation effects, we subdivide the SAW structures in transverse direction into several parallel waveguiding channels (N regions), and take, as the wave-describing quantity, a two-dimensional scalar potential function. By doing so, we obtain a complete set of orthonormal modes into which an arbitrary transverse excitation function can be expanded to study its propagation. The general mode spectrum includes a discrete spectrum of bound modes and continuous spectra of semi-bound and radiation modes. We calculate all types of modes by making use of the stack matrix technique. The present work, which arose from the requirement of creating an efficient mathematical tool for the simulation of TCRFs, provides the complete analysis of general SAW multi-channel structures. 相似文献
93.
Summary Polymerizable enamines were synthesized by the reaction of 2-acetoacetoxyethyl methacrylate (AAEMA) with various aliphatic mono- and diamines. The enamines were characterized by elemental analyses, IR,1H NMR and13C NMR spectroscopy. Radical polymerization of synthesized enamines yielded polymers with pendant enamine groups which were also prepared by the reaction of poly(AAEMA) with the corresponding amines. 相似文献
94.
95.
96.
Willy Jankowski 《国际钢铁研究》1977,48(12):629-632
Definition von Eigenspannungen. Verfahren zum Nachweis und zur Messung von Eigenspannungen. Vorstellung eines neuen Meßverfahrens zur Bestimmung der Höhenverteilung von Eigenspannungen. Mechanische und spannungsoptische Modellversuche. Anwendung des Meßverfahrens auf Schweißeigenspannungen. 相似文献
97.
Robust DNA microarray image analysis 总被引:6,自引:0,他引:6
Norbert?Br?ndleEmail author Horst?Bischof Hilmar?Lapp 《Machine Vision and Applications》2003,15(1):11-28
DNA microarrays are an increasingly important tool that allow biologists to gain insight into the function of thousands of genes in a single experiment. Common to all array-based approaches is the necessity to analyze digital images of the scanned DNA array. The ultimate image analysis goal is to automatically quantify every individual array element (spot), providing information about the amount of DNA bound to a spot. Irrespective of the quantification strategy, the preliminary information to extract about a spot includes the mapping between its location in the digital image and its possibly distorted position in the spot array (gridding). We present a gridding approach divided into a spot-amplification step (matched filter), a rotation estimation step (Radon transform), and a grid spanning step. Quantification of the spots is performed by robustly fitting of a parametric model to pixel intensities with the help of M-estimators. The main advantage of parametric spot fitting is its ability to cope with overlapping spots. If the goodness-of-fit is too bad, a semiparametric spot fitting is employed. We show that our approach is superior to simple quantification strategies such as averaging of the pixel intensities. The system was extensively tested on 1740 images resulting from two DNA libraries.Received: 15 June 2001, Accepted: 21 July 2002, Published online: 3 June 2003
Correspondence to: Norbert Brändle 相似文献
98.
Kuczewski B Marquardt CM Seibert A Geckeis H Kratz JV Trautmann N 《Analytical chemistry》2003,75(24):6769-6774
Capillary electrophoresis (CE) was coupled to ICPMS in order to combine the good performance of this separation technique with the high sensitivity of the ICPMS for the analysis of plutonium and neptunium oxidation states. The combination of a fused-silica capillary with a MicroMist AR 30-I-FM02 nebulizer and a Cinnabar small-volume cyclonic spray chamber yielded the best separation results. With this setup, it was possible to separate a model element mixture containing neptunium (NpO2(+)), uranium (UO2(2+)), lanthanum (La3+), and thorium (Th4+) in 1 M acetic acid. The same conditions were also suitable for the separation of various oxidation states of plutonium and neptunium in different aqueous samples. All separations were obtained within less than 15 min. A detection limit of 50 ppb identical with 2 x 10(-7) M (3-fold standard deviation of a blank) was achieved. To prove the negligible disturbance of the plutonium and neptunium redox equilibria during the CE separations, plutonium and neptunium speciation by CE-ICPMS in acidic solutions was compared with the results of UV/visible absorption spectroscopy and was found to be in good agreement. The CE-ICPMS system was also applied to study the reduction of Pu(VI) in a humic acid-containing groundwater at different pH values. 相似文献
99.
Lohbauer U Frankenberger R Krämer N Petschelt A 《Journal of materials science. Materials in medicine》2003,14(12):1047-1053
Elastic modulus (EM), initial fracture strength (FS) and flexural fatigue limit (FFL) of dental restorative materials were measured in a simulated oral environment to correlate mechanical response under the influence of water with the chemical nature of the test materials under investigation. One resin composite (RC; Tetric Ceram, Ivoclar-Vivadent Corp., Liechtenstein), an ion-leaching resin composite (ILRC; Ariston pHc, Ivoclar-Vivadent Corp., Liechtenstein) a compomer (CO; Dyract AP, Dentsply Corp., USA) and a glass-ionomer cement (GIC; Ketac Molar, 3MEspe Corp., Germany) were tested. Static EM, FS and dynamic FFL experiments were performed. The FFL was determined under cyclic loading for 10(5) cycles in terms of a staircase approach. The materials were stored for 1, 8, 30, 90 and 180 days in 37 degrees C distilled water, respectively. The RC degraded over time due to water adsorption followed by failure within the resin matrix. The ILRC suffered from a pronounced decrease in FS as well as in FFL due to a constant ion-leaching and macroscopic crack growth. CO failed over time due to resin-filler interface cracking. The GIC exhibited improved mechanical performance over time due to a post-hardening mechanism. The results reveal the necessity for substantial preclinical evaluation of direct restorative materials. The material parameters under investigation are capable of predicting clinical performance over time. 相似文献
100.
Zusammenfassung Nachdem wir im letzten Artikel die Funktionen einer digitalen Signatur kennen gelernt und den Bedarf an kryptographischen
Prüfsummen und Zertifikaten erl?utert haben, wollen wir diesmal auf die Infrastrukturen zur Verwaltung von Schlüsseln bzw.
Zertifikaten eingehen: die so genannten Public-Key-Infrastrukturen (PKI).
Prof. Dr. Norbert Pohlmann ist Gesch?ftsführender Direktor des Instituts für Internet-Sicherheit der Fachhochschule Gelsenkirchen.
Malte Hesse ist Mitarbeiter am Institut für Internet-Sicherheit der Fachhochschule Gelsenkirchen. 相似文献