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Time dependent behavior of elements combining ultra-high performance fiber reinforced concretes (UHPFRC) and reinforced concrete 总被引:1,自引:1,他引:0
Structural elements combining Ultra-High Performance Fiber Reinforced Concretes (UHPFRC) and concrete offer a high potential
in view of rehabilitation and modification of existing structures. The investigation of the time-dependent behavior of composite
“UHPFRC-concrete” elements is a fundamental step in the determination of durability and serviceability. For this, an experimental
program was conducted on large composite “UHPFRC-concrete” beams and a numerical model was validated with the test results.
The experimental results and a parametric study performed with the numerical model showed that UHPFRC and normal strength
reinforced concrete are compatible in the long-term and that the critical period of composite “UHPFRC-concrete” elements are the first 90 days after the casting of the UHPFRC layer. Thus, the high potential
of such composite elements can be exploited also in the long term. 相似文献
4.
We present an algorithm for combining the elements of subsequences of a sequence with an associative operator. The subsequences are given by a sliding window of varying size. Our algorithm is greedy and computes the result with the minimal number of operator applications. 相似文献
5.
Albrethsen J Kaas A Schönle E Swift P Kocova M Gammeltoft S Hansen L Mortensen HB 《Proteomics. Clinical applications》2009,3(3):383-393
Proteomics analysis of serum from patients with type 1 diabetes (T1D) may lead to novel biomarkers for prediction of disease and for patient monitoring. However, the serum proteome is highly sensitive to sample processing and before proteomics biomarker research serum cohorts should preferably be examined for potential bias between sample groups. SELDI‐TOF MS protein profiling was used for preliminary evaluation of a biological‐bank with 766 serum samples from 270 patients with T1D, collected at 18 different paediatric centers representing 15 countries in Europe and Japan over 2 years (2000–2002). Samples collected 1 (n = 270), 6 (n = 248), and 12 (n = 248) months after T1D diagnosis were grouped across centers and compared. The serum protein profiles varied with collection site and day of analysis; however, markers of sample processing were not systematically different between samples collected at different times after diagnosis. Three members of the apolipoprotein family increased with time in patient serum collected 1, 6, and 12 months after diagnosis (ANOVA, p<0.001). These results support the use of this serum cohort for further proteomic studies and illustrate the potential of high‐throughput MALDI/SELDI‐TOF MS protein profiling for evaluation of serum cohorts before proteomics biomarker research. 相似文献
6.
Localized Synthesis of Iron Oxide Nanowires and Fabrication of High Performance Nanosensors Based on a Single Fe2O3 Nanowire 下载免费PDF全文
Oleg Lupan Vasile Postica Niklas Wolff Oleksandr Polonskyi Viola Duppel Victor Kaidas Eugen Lazari Nicolai Ababii Franz Faupel Lorenz Kienle Rainer Adelung 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(16)
A composed morphology of iron oxide microstructures covered with very thin nanowires (NWs) with diameter of 15–50 nm has been presented. By oxidizing metallic Fe microparticles at 255 °C for 12 and 24 h, dense iron oxide NW networks bridging prepatterned Au/Cr pads are obtained. X‐ray photoelectron spectroscopy studies reveal formation of α‐Fe2O3 and Fe3O4 on the surface and it is confirmed by detailed high‐resolution transmission electron microscopy and selected area electron diffraction (SAED) investigations that NWs are single phase α‐Fe2O3 and some domains of single phase Fe3O4. Localized synthesis of such nano‐ and microparticles directly on sensor platform/structure at 255 °C for 24 h and reoxidation at 650 °C for 0.2–2 h, yield in highly performance and reliable detection of acetone vapor with fast response and recovery times. First nanosensors on a single α‐Fe2O3 nanowire are fabricated and studied showing excellent performances and an increase in acetone response by decrease of their diameter was developed. The facile technological approach enables this nanomaterial as candidate for a range of applications in the field of nanoelectronics such as nanosensors and biomedicine devices, especially for breath analysis in the treatment of diabetes patients. 相似文献
7.
Self-assembly is the process by which objects aggregate independently and form complex structures. One of the theoretical
frameworks in which the process of self-assembly can be embedded and formally studied is that of tile systems. A Wang tile
is a square unit, with glues on its edges, attaching to other tiles which have matching glues, and forming larger and larger
structures. In this paper we concentrate over two basic, but essential, self-assembling structures done by Wang tiles. The
first one, called ribbon, is a non-self-crossing wire-like structure, in which successive tiles are adjacent along an edge,
and where tiles are glued to their predecessor and successor by use of matching glues. The second one, called zipper, is a
similar contiguous structure, only that here, all touching tiles must have matching glues on their abutting edges, independently
of their position in the structure. In case of Wang tiles, it has been shown that these two structures are equivalent. Here
we generalize this result for the case when the tiles have eight glues, four on their edges and four on their corners. Thus
we show that an eight neighborhood dependency, namely the Moore neighborhood, can be simulated by a quasi-linear dependency. 相似文献
8.
Eugen Seel Elisabeth Zeeb und Karl Reihling 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1919,37(1-2):1-17
Zusammenfassung Die Ergebnisse der chemischen Untersuchung von Fleisch- und Wurstwaren sind als ausschließliche Grundlage für ihre Beurteilung durchaus ungenügend; denn wir können noch nicht annähernd sämtliche chemischen Einzelbestandteile des Fleisches und der Wurstwaren mittels der im praktischen Laboratorium anwend aren Methoden nachweisen und noch viel weniger diese Einzelbestandteile quantitativ ermitteln. Es läßt sich aber auch im allgemeinen durch die chemische Untersuchung allein nicht feststellen, ob eine unter bestimmten Namen in den Handel gebrachte Ware die in diesem Namen zum Ausdruck gebrachten Fleischbestandteile tatsächlich enthält, wie z. B., ob Leberwurst Leber enthält, ferner ob minderwertige oder verbotene Organund Gewebeteile beigemischt sind oder nicht.Daher ist die mikroskopische Untersuchung, besonders in gerichtlichen Fällen, unerläßlich.Die nur auf mikroskopischem Wege erreichbare Kenntnis der in Fleisch und Wurstwaren enthaltenen Gewebe und Organe erleichtert bezw. ermöglicht die Beurteilung von Fleisch- und Wurstwaren nicht nur in vorgenannter Richtung, sondern sie erleichtert auch sehr wesentlich die Beurteilung ihres Gesamtwertes. Dieser ist verschieden je nach dem Vorhandensein der mikroskopisch nachzuweisenden Gewebe bezw. Organe und nach deren Wassergehalt. Letzterer wiederum ist z. B. bei Muskelfleisch konstanter und liegt in engeren Grenzen als bei den drüsigen Organen; im elastischen Bindegewebe ist er bedeutend niedriger als im kollagenen Bindegewebe oder im Muskelfleisch.In der vorliegenden Arbeit ist der Versuch gemacht, die mikroskopischen Schnitte der wichtigsten in Betracht kommenden Gewebe und Organe in gekochtem Zustande so zu charakterisieren, daß sie in Gemischen einwandfrei identifiziert werden können.Die Technik der mikroskopischen Untersuchung von Fleisch- und Wurstwaren ist unter Angabe bewährter Verfahren eingehend dargestellt. 相似文献
9.
An assembly of hemispherical Ag nanoparticles is prepared by solid‐state dewetting of thin Ag film deposited on the sapphire substrate. The in situ nanomechanical compression testing of the particles with a flat diamond punch inside the scanning electron microscope demonstrates the deformation behavior typical for the nucleation‐controlled plasticity: high elastic deformation followed by an abrupt particles collapse. The latter is associated with the dislocations nucleation in otherwise pristine particle. The average contact pressure in the contact zone at the onset of dislocation‐controlled plasticity is about 8 GPa, and does not depend on particle size. This observation supports the hypothesis that the pseudoelasticity of much smaller Ag nanoparticles is intrinsically related to their ultrahigh strength. A stress‐induced diffusion along the particle–substrate and particle–punch interfaces is identified as a factor controlling the pseudoelastic deformation. The corresponding diffusion model allows estimating the room‐temperature self‐diffusion coefficient of Ag along the Ag–W and Ag–zirconia interfaces, which is quite close to the estimated value of the grain boundary self‐diffusion coefficient in Ag. Based on this finding, the map of pseudoelastic deformation of crystalline materials is proposed. 相似文献
10.