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Journal of Bionic Engineering 2017年第3期14卷 520-531页

作者： wolfgang Tiilmann Dominic Stangier Nelson Filipe Lopes Dias Institute of Materials Engineering TU Dortmund 44227 Dortmund Germany Leonhard-Euler-Strafle 2

Bionic surface structures, inspired by the flora, were developed for Sheet-Bulk Metal Forming （SBMF） in order to locally control the friction condition by adjusting the wetting behavior. Five bionic structures were micromilled on ASP 2023 in annealed as well as hardened and tempered conditions. Subsequently, the structured surfaces were plasma-nitrided and coated with a CrA1N thin film. The influence of the treatment method on the structural geometry was investigated with the aid of a scanning electron microscope and 3D-profilometer. The wetting behaviors of water and deep drawing oil （Berufluid ST6007） on bionic surfaces were evaluated using contact angle measurements. The resulting micro-milled structures exhibit an almost identical shape as their bionic models. However, the roughness of the structured surfaces is influenced by the microstructure. The combination of plasma-nitriding and Physical Vapor Deposition （PVD） leads to an increase in roughness. All bionic struc- tures possess higher contact angles than that of the unstructured surfaces when wetted by water. This can be explained by the fact that the structural elevations block the spreading. When the bionic surfaces are wetted by deep drawing oil, the lubricant spreads in the structural cavities, leading to smaller contact angles. Furthermore, the anisotropy of the structure has an influence on the wetting behavior.

关键词： bionic structures sheet-bulk metal forming CrA1N PVD-duplex treatment wetting behavior

Semi-hot Stamping as an Improved Process of Hot Stamping

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Journal of Materials Science & Technology 2011年第4期27卷 369-376页

作者： Malek Naderi Mostafa Ketabchi Mahmoud Abbasi wolfgang Bleck Department of Mining and Metallurgy Amirkabir University of Technology Department of Ferrous Metallurgy RWTH-Aachen University

Reducing the forming load, deletion of springback, increasing the formability of sheets as well as producing high strength parts are the main reasons to apply hot stamping process. Hot stamping process and 22MnB5 steels are the state of the art process and grades, respectively; however novel processes and steel grades are under considerations. In the current research, behavior of the steel grade MSW1200 blanks under semi and fully hot stamping processes was characterized. During semi-hot stamping process, the blank was firstly heated to a temperature of about 650℃ and then formed and quenched in the die assembly, simultaneously. Microstructure and mechanical properties of semi and fully hot stamped blanks were studied and the results were compared with those of normally water/air quenched blanks. The hot stamped blanks attained the strength values as high as water quenched blanks. The highest ductility and consequently, the best formability were achieved for the blank which had been semi-hot stamped. It was concluded that for the mentioned steel, semi-hot stamping process could be considered as an improved thermo-mechanical process which not only guaranteed a high formability, but also led to ultra high strength values.

关键词： Semi-hot stamping Hot stamping MSW1200 steel Mechanical properties

Effect of Different Calcination Temperatures and Post Annealing on the Properties of Acetic Acid Based Sol-Gel (Na_(0.5)K_(0.5))NbO_3(NKN) Thin Films

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Journal of Materials Science & Technology 2013年第2期29卷 142-148页

作者： Sebastian Wiegand Stefan Flege Olaf Baake wolfgang Ensinger Materials Analysis Group Department of Materials and Geosciences Technische Universitt Darmstadt Petersenstrasse 23 64287 Darmstadt Germany

（Na0.5K0.5）NbO3 （NKN） lead free thin films were synthesized by means of an acetic acid based sol-gel process on Pt/Ti/SiO2/Si substrates. Na-acetate, K-acetate and Nb-pentaethoxide were used as metal precursors and acetic acid as the solvent. The effect of different calcination temperatures on the properties of the NKN films was investigated by X-ray diffraction, scanning electron microscopy, leakage current and hysteresis measurements. Low calcination temperatures led to low currents at high electric fields whereas high calcination temperatures led to low currents at low electric fields. Based on these findings calcination at low temperature was combined with a post annealing treatment. Low leakage currents of 4×10^-4 A/cm2 at 150 kV/cm and 2Pr and 2Ec values of 28 μC/cm2 and 150 kV/cm, respectively, could be obtained. All films were single phase NKN with random crystal orientations and no crack or pore formation was visible on the surface.

关键词： Sol-gel process (Na0.5K0.5)NbO3 Thin film Perovskite Lead-free Piezo material

Long-term monitoring data reveal effects of age,population density,and environmental aspects on hatching success of Common Cranes(Grus grus)

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Avian Research 2022年第3期13卷 347-355页

作者： Isabel Barwisch wolfgang Mewes Angela Schmitz Ornes AG Vogelwarte Zoological Institute and MuseumUniversity of GreifswaldSoldmannstr.23GreifswaldGermany Grüner Weg 3 19395Plau Am SeeOT KarowGermany

Facing climate and land use change,a species’ability to successfully adapt to changing environments is crucial for its *** drainage and intensification of agriculture and forestry set wetlands and associated species at risk of population *** population of Common Cranes(Grus grus)has experienced considerable fluctuations over the last *** increasing population numbers,hatching success seemed to have decreased over the last *** aim of this study was to identify factors influencing hatching success and nest survival of Common Cranes based on analyses of long-term individual-based monitoring data from northeastern Germany and evaluate the species ability to adapt to changing *** success decreased over the course of the study period from 0.75 to ***,nest survival and hatching success did not vary across different nesting habitats,whereas factors such as female age,timing of nest initiation and breeding pair density were found to have significant effects on hatching *** females showed higher hatching success,even though the proportion of unhatched eggs was highest in females aged 20 years or *** nest initiation had a positive effect on hatching *** levels are more favorable early in the nesting season,whereas increasing evaporation with time causes water levels to decrease,granting easier access for *** of female age,hatching success decreased with increasing numbers of breeding pairs within a 2-km radius around a nesting *** population densities intensify competition for resources and promote intraspecific interactions,affecting reproductive outcome *** study gives first insights into mechanisms behind population regulation in Common Cranes,highlighting the importance of population dynamics and individual *** suggest to further investigate density dependent effects including landscape and habitat features as well as reproduct

关键词： Adaptation Age Cranes Grus grus Habitat Nest survival Population density Reproduction

A new hybrid piezoelectric ultrasonic motor with two stators

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Journal of Central South University of Technology 2005年第3期12卷 324-328页

作者：易幼平 wolfgang Seemann Rainer Gausmann 钟掘 College of Mechanical and Electrical Engineering Central South University Changsha 410083China Institut für Technische Mechanik Universitt KarlsruheKarlsruhe 76128Germany AG Maschinendynamik Universitt Kaiserslautern Kaiserslautern 67653 Germany

A new hybrid piezoelectric ultrasonic motor, which consists of one rotor and two stators, was proposed in this paper. In order to match the resonance frequencies of longitudinal vibration and torsional vibration excited in the stators, a symmetrical structure was adopted in design of the motor. A so-called mass matching method, namely adding two rings to the outside circumference of the two stators respectively, was used to adjust the resonance frequencies of these two vibrations. A finite element model was developed using ANSYS software for the purpose of analyzing the resonance frequencies of longitudinal vibration and torsional vibration as well as the function of the adjusting rings. The results show that the resonance frequency of torsional vibration varies with the position of the ring, but the resonance frequency of longitudinal vibration changes little. By means of adjusting the mass and the position of the rings, the first order resonance frequency of longitudinal vibration is coincided with that of torsional vibration and the value is 20.75kHz. An experimental prototype motor was fabricated according to the analytical results and its performance is in agreement with the theoretical predictions. The speed of motor reaches the maximum 92r/min at the working frequency 19.0kHz.

关键词： piezoelectric ultrasonic motor lead zirconate titanate resonance frequency vibration

The Unfinished Text or Literature as Palimpsest towards Lu Xun and His Relevance to the Present

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Frontiers of Literary Studies in China-Selected Publications from Chinese Universities 2013年第4期7卷 541-550页

作者： wolfgang Kubin Department for Overseas Chinese Studies Beijing Foreign Studies University Beijing 100089 China

The fact that Lu Xun is no longer regarded as the most important Chinese writer of the 20th century raises many questions. Is there only one benchmark for good literature, or are there different norms？ To what extent are these norms dictated by the market？ Questions like these relate to the issue of evaluation. Is literature still evaluated according to the internationally recognized definition of ＂modernity＂ that prevailed before World War II, or is it unfair to judge contemporary writers according to standards that dominated before 19497 The reason why contemporary Chinese literature （after 1949） might sometimes seem somehow lacking in comparison with modern Chinese literature （1912-49） might be found in historical changes in the role of the narrator in the novel. Literature after 1949 often returns to the omnipresent narrator, whose comments can be taken for granted. But, in the works of Lu Xun, the reader is often confronted with a narrator who is not reliable. In this way, the literature becomes ambivalent, and it is precisely this ambivalence that makes the literature ＂modern,＂ as the reader has to decide which voice he or she is going to trust. It is also ambivalence which turns a narrating ＇T＇ into a fictional character, which cannot be equated with the （real） author.

关键词： literary Lu Xun modernity memory ambivalence voice in the text market benchmark for literature unreliable narrator figure of speech

TAX MORALE IN CLASSICAL ATHENS

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Journal of Ancient Civilizations 2019年第2期34卷 273-288,330页

作者： wolfgang Franzen Forschungsstelle für empirische Sozialökonomik e.V.(fores)(Office for Empirical Research on Social Economics Cologne)

Tax psychology is an interdisciplinary approach to explain attitudes and behavior of *** tax-psychological surveys usually focus on empirical data from contemporary societies,this article relies on historical studies of classical *** suggest that,due to specific political,social,and cultural conditions,in classical Athens tax morale has been positive and tax compliance rather high.

关键词： CLASS contemporary explain

HAUSDORFF MEASURE OF UNIFORM SELF-SIMILAR FRACTALS

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Analysis in Theory and Applications 2010年第1期26卷 84-100页

作者： wolfgang Kreitmeier University of Passau Innstraβe

Let d ≥ 1 be an integer and E a self-similar fractal set, which is the attractor of a uniform contracting iterated function system （UIFS） on R^d. Denote by D the Hausdorff dimension, by H^D（E） the Hausdorff measure and by diam（E） the diameter of E. If the UIFS is parametrised by its contracting factor c, while the set ω of fixed points of the UIFS does not depend on c, we will show the existence of a positive constant depending only on ω, such that the Hausdorff dimension is smaller than one and H^O（E） = diam（E）^D if c is smaller than this constant. We apply our result to modified versions of various classical fractals. Moreover, we present a parametrised UIFS, where ω depends on c and show the inequatily H^D（E）〈 diam（E）^D, if c is small enough.

关键词： self-similar set Hausdorff measure

Latency arbitrage and the synchronized placement of orders

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Financial Innovation 2023年第1期9卷 2650-2667页

作者： wolfgang Kuhle Department of Economics Corvinus UniversityBudapestHungary MEA Max Planck Institute for Social Law and Social PolicyMunichGermany Zhejiang University HangzhouChina

We argue that owing to traders’inability to fully express their preferences over the execution times of their orders,contemporary stock market designs are prone to latency *** turn,we propose a new order type,which allows traders to specify the time at which their orders are executed after reaching the *** recent latency data,we demonstrate that the order type proposed here allows traders to synchronize order executions across different exchanges,such that high-frequency traders,even if they operate at the speed of light,can no-longer engage in latency arbitrage.

关键词： Market design High-frequency trading Latency arbitrage

Effects of Bentonite,Hydrogel and Biochar Amendments on Soil Hydraulic Properties from Saturation to Oven Dryness

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Pedosphere 2019年第5期29卷 598-607页

作者： Osama M0HAWESH wolfgang DURNER Department of Plant Production Faculty of AgricultureMutah UniversityKarak 61710 (Jordan) Division of Environmental Science and Technology Graduate School of AgricultureKyoto UniversityKyoto 6110011 (Japan) Institute of Geoecology Technical University of BraunschweigLanger Kamp 19cBraunschweig 38106 (Germany)

Effects of hydrogel, bentonite, and biochar as soil amendments on soil hydraulic properties and improving water availability from saturation to oven dryness were investigated. Soils were mixed with hydrogel (0.10%, 0.25%, and 0.50%), bentonite (0.5%, 1.0%, and 2.5%), and biochar (1.0%, 2.5%, and 5.0%) as soil amendments (weight:weight). Three methods (extended multistep outflow (XMSO), evaporation (EVA), and WP4 dewpoint potentiometer) were used to measure soil hydraulic properties from saturation to oven dryness. The cumulative XMSO results were more uniform across all the applied pressure steps for the amended soils. The EVA exhibited a shorter linear decrease during the first evaporation stage and a lower evaporation rate during the second evaporation stage. The WP4 results also exhibited that soil amendments increased the soil water content of the amended soils at low matric potentials. The results of soil water retention curves revealed that the unamended soil retained less water at any matric potential compared to the amended soils. Soil hydraulic conductivity decreased with increasing amount of soil amendments. The saturated hydraulic conductivity was higher for the unamended soil than the soils amended w计h 2.5% bentonite, 0.50% hydrogel, and 5.0% biochar by 11, 3, and 18 times, respectively. These results suggested that soil amendments improved soil water retentivity, which confirmed the appropriateness of these soil amendments for potential use in sandy soil improvements. However, field experiments and economical perception studies should be considered for further investigation.

关键词： evaporation extended multistep outflow soil amendment soil matric potential soil moisture soil water retentivity water availability WP4 dewpoint potentiometer