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Frontiers of Mechanical Engineering 2023年第4期18卷 183-193页

作者： Alexander SCHMIDT Felix JENSCH sebastian HÄRTEL Chair of Hybrid Manufacturing Brandenburg University of TechnologyCottbus 03046Germany

Many processes may be used for manufacturing functionally graded *** them,additive manufacturing seems to be predestined due to near-net shape manufacturing of complex geometries combined with the possibility of applying different materials in one *** adjusting the powder composition of the starting material layer by layer,a macroscopic and step-like gradient can be *** further improve the step-like gradient,an enhancement of the in-situ mixing degree,which is limited according to the state of the art,is *** this paper,a novel technique for an enhancement of the in-situ material mixing degree in the melt pool by applying laser remelting(LR)is *** effect of layer-wise LR on the formation of the interface was investigated using pure copper and low-alloy steel in a laser powder bed fusion *** cross-sectional selective electron microscopic analyses were carried *** applying LR,the mixing degree was enhanced,and the reaction zone thickness between the materials was ***,an additional copper and iron-based phase was formed in the interface,resulting in a smoother gradient of the chemical composition than the case without *** Marangoni convection flow and thermal diffusion are the driving forces for the observed effect.

关键词： multi-material additive manufacturing(MMAM) functionally graded materials(FGMs) laser powder bed fusion(L-PBF) laser remelting(LR) pure copper

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

Synthesis and Characterization of(Na_(0.5)K_(0.5))NbO_3(NKN) Thin Films Formed by a Diol-based Sol-gel Process

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Journal of Materials Science & Technology 2012年第6期28卷 500-505页

作者： sebastian Wiegand Stefan Flege Olaf Baake Wolfgang Ensinger Technische Universitt Darmstadt Department of Materials and GeosciencesMaterials Analysis GroupPetersenstrasse 2364287 DarmstadtGermany

Lead-free （***0.5）Nb03 （NKN） thin films were fabricated by spin coating on Pt/Ti/SiO2/Si substrates by a diol-based sol-gel process. Na-acetate, K-acetate, Nb-pentaethoxide and 1,3 propanediol were used to prepare the NKN precursor solution. Thermal analysis showed two characteristic temperatures of 360 and 600℃. Based on these temperatures, a heat treatment program with pyrolysis at 360℃ and calcination at 600℃ after every layer was used. To avoid inhomogeneities and secondary phases, an excess of sodium and potassium was necessary. To evaluate the proper excess amount of sodium and potassium secondary ion mass spectrometry （SIMS） lateral element maps and X-ray diffraction （XRD） patterns were recorded. An excess amount of 20% led to homogeneous distribution of the elements and to single phase perovskite NKN films with random crystal orientation. Scanning electron microscopy （SEMI images showed a pore free surface with 100 nm grains. The leakage current measurements showed a current of lx10-3 A/cm2 at 150 kV/cm.

关键词： Sol-gel process (Nao.sK0.5)NbO3 Thin film Perovskite Lead-free Piezo material

Computational studies on the seismic response of the State Route 99 bridge in Seattle with SMA/ECC plastic hinges

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Frontiers of Structural and Civil Engineering 2019年第1期13卷 149-164页

作者： Jiping GE M.Saiid SAIIDI sebastian VARELA School of Urban Construction and Safety Engineering Shanghai Institute of TechnologyShanghai 201418China Department of Civil and Environmental Engineering University of NevadaRenoNV 89557USA Structural Engineering Group Freese and Nichols Inc.Fort WorthTX 76109USA

This paper reports a computational study on the seismic response of a three-span highway bridge system incorporating conventional and novel substructure details for improved seismic *** bridge has three continuous spans supported by two single-column piers and integral abutments founded on drilled *** will be the first full-scale highway bridge to use superelastic shape memory alloy bars (SMA)and engineered cementitious composite (ECC)to mitigate column plastic hinge damage and minimize residual displacements after a strong earthquake. A three-dimensional computational model capturing the nonlinear constitutive response of the novel materials and the effects of dynamic soil-structure interaction was developed to assess the seismic response of the bridge in finite-element software *** versions of the same bridge were analyzed and compared,one with conventional cast-in-place reinforced concrete columns,and the other with top plastic hinges incorporating Nickel-Titanium (NiTi)SMA reinforcing bars and *** novel SMA/ECC plastic hinges were found to substantially reduce damage and post-earthquake residual displacements in the bridge substructure,but led to larger maximum drifts relative to the bridge with conventional reinforced concrete plastic *** analysis results suggested that the novel plastic hinges could lead to improved post-earthquake serviceability of bridges after intense earthquakes.

关键词： seismic design analytical simulation near-fault earthquakes shape memory alloy engineered cementitious composite self-centering

First Record of the Gekkonid Genus Cnemaspis Strauch, 1887 from Gunung Mulu National Park, Northern Sarawak, East Malaysia may Represent an Undescribed Species

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Asian Herpetological Research 2014年第3期5卷 209-212页

作者： André KOCH sebastian SCHULZ Zoological Research Museum Alexander Koenig (ZFMK) Leibniz-Institute for terrestrial Biodiversity

We provide confirmed photographic evidence for the previously overlooked occurrence of the polyphyletic Asian gecko genus Cnemaspis from Gunung Mulu National Park, the world-renowned UNESCO natural heritage site in northern Sarawak, East Malaysia. This new record from Sarawak province represents a remarkable range extension for Cnemaspis cf. kendallii by 550 km to the northeast and denotes the most northern occurrence of the genus in Borneo. Our new finding makes it very likely that these gekkonid lizards also inhabit appropriate limestone karst habitats in adjacent Sabah, Brunei, and Kalimantan. Given the visible differences in the Mulu specimen compared to those from the remaining distribution range on Borneo and the Malaysian Peninsula together with the fact that numerous Cnemaspis species are restricted to small areas, it seems plausible that another undescribed, rather cryptic and possibly locally endemic Bornean species is involved. Lastly, the new record contributes to the importance of the Mulu National Park as a major conservation area in East Malaysia of international concerns.

关键词： Southeast Asia Borneo Gekkonidae herpetofaunal diversity new record

Laser-induced thermal lens study of the role of morphology and hydroxyl group in the evolution of thermal diffusivity of copper oxide

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Chinese Physics B 2021年第6期30卷 588-593页

作者： Riya sebastian M S Swapna Vimal Raj S Sankararaman Department of Optoelectronics University of KeralaTrivandrum 695581KeralaIndia

The paper explores the evolution of thermal behavior of the material by studying the variations in thermal diffusivity using the single beam thermal lens(TL) technique. For this purpose, the decomposition of Cu(OH)_(2) into CuO is studied in a time range up to 120 h, by subjecting the sample to morphological, structural, and spectroscopic characterizations. The time evolution of thermal diffusivity can be divided into three regions for demonstrating the dynamics of the reaction. When the reaction is complete, the thermal diffusivity is also found to be saturated. In addition to the morphological modifications,from rods to flakes, the variations in the amount of hydroxyl group are attributed to be responsible for the enhancement of base fluid's thermal diffusivity by 165%. Thus the study unveils the role of hydroxyl groups in the thermal behavior of CuO.

关键词： thermal diffusivity CuO thermal lens morphology hydroxyl group

THE COLLAPSE OF EARLY MESOPOTAMIAN EMPIRES–A HOMEMADE DISASTER?

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Journal of Ancient Civilizations 2021年第1期36卷 1-31,137页

作者： sebastian Fink University of Innsbruck

If we survey the fall of Mesopotamian empires from the beginning of written sources to the end of the Neo-Babylonian Empire we find one astonishing similarity:the warlike people that finally destroyed these empires came from the East.A number of factors,not at least geography,might explain this,but here I want to focus on the effect the Mesopotamian empires had on the bordering regions themselves and discuss the possibility that the constitution of these organized political actors pushing back against the empire was a result of Mesopotamian imperial politics themselves determined by a poor evaluation of the empire’s ability to exercise direct control of areas where military actions took *** aim of this paper is to build on earlier work and investigate the fall of the empires of Akkad and Ur III under a systemic perspective,in order to understand which factors might have caused the decline and fall of these empires that were not merely *** reasons have been suggested for the fall of Mesopotamian empires,like climatic change(Kinnier-Wilson 2005),salinization of the soil(Powell 1985),or the arrival of new ***,I want to focus on the question of whether this“arrival of new people”may be better described as the establishment of opposing political *** are often described as coming out of nowhere,but I would like to suggest that this was the result of an ethnogenesis or secondary state formation at the border of the empire.

关键词： DISA destroyed finally

Minor Movies： On the Deterritorialising Power of Wong Kar-wai＇s Works

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Frontiers of Literary Studies in China-Selected Publications from Chinese Universities 2012年第4期6卷 582-597页

作者： sebastian Nestler Department of Media and Communication University of Klagenfurt Klagenfurt 9020 Austria

The article approaches Wong Kar-wai＇s cinematic work using the notion of ＂minor literature＂ as coined by Gilles Deleuze and F61ix Guattari. Minor literature--or, in other words, minor language signifies oppositional/resistant uses of a major/hegemonic language. It appropriates hegemonic language and deterritorialises it by re-signifying its original meanings. By transferring this concept from literature to cinema, we can describe Hong Kong cinema, which deterritorialises Hollywood cinema, as a minor cinema in relation to Hollywood. Following this interpretation, Wong Kar-wai＇s movies appear as a ＂minor language of a minor cinema＂ because they are significantly different from Hong Kong＇s mainstream action cinema. Consequently, Wong＇s movies possess a high level of deterritorialising power, which opens up new spaces of meaning and gives voice to positions usually oppressed by mainstream cinema. Finally, a close reading of Wong＇s movie Happy Together shows how ＂minor movies＂ challenge the mainstream＇s unison and give space to a resistant and transforming polyphony.

关键词： film studies cultural studies post-structuralism Hong Kong cinema,Wong Kar-wai minor movies Happy Together

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面向软件缺陷数据的协同过滤抽样推荐算法

西南师范大学学报（自然科学版） 2021年第11期46卷 46-55页

作者：吴克奇崔梦天 mariani manuel sebastian 张翼成谢琪周绪川西南民族大学计算机系统国家民委重点实验室成都610041 苏黎世大学商业管理系瑞士苏黎士8050 弗里堡大学物理系瑞士弗里堡1700

基于没有一种抽样方法能在所有缺陷数据集上表现良好且为软件缺陷数据选择适用抽样方法是必要的这一前提,提出了一种面向软件缺陷数据的协同过滤抽样推荐算法.首先,在历史缺陷数据上对主流抽样方法进行排序,以得到在特定分类算法和度量... 详细信息

基于没有一种抽样方法能在所有缺陷数据集上表现良好且为软件缺陷数据选择适用抽样方法是必要的这一前提,提出了一种面向软件缺陷数据的协同过滤抽样推荐算法.首先,在历史缺陷数据上对主流抽样方法进行排序,以得到在特定分类算法和度量指标下主流抽样方法的性能排序;然后,计算新缺陷数据和历史缺陷数据之间的杰卡德相似系数,以挖掘数据之间的相似性;最后,将抽样方法排名和数据相似性的信息结合起来构建一个推荐网络,利用协同过滤算法为新的软件缺陷数据推荐适用的抽样方法.通过Python对多个NASA缺陷数据集进行仿真实验,实验结果表明面向软件缺陷数据的协同过滤抽样推荐算法是可行和有效的.

关键词：软件缺陷数据抽样推荐算法协同过滤数据相似性

A Comprehensive Review of COVID-19 Virology, Vaccines, Variants, and Therapeutics

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Current Medical Science 2021年第6期41卷 1037-1051页

作者： Lauren Forchette William sebastian Tuoen LIU Department of Biomedical Sciences West Virginia School of Osteopathic Medicine400 Lee Street NorthLewisburgWest Virginia 24901USA

Summary:Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the causative pathogen of Ihe coronavirus disease 2019(COVID-19),has caused more than 179 million infections and 3.8 million deaths *** the past year,multiple vaccines have already been developed and used,while some others are in the process of being ***,the emergence of new mutant strains of SARS-CoV-2 that have demonstrated immune-evading characteristics and an increase in infective capabilities leads to potential ineffectiveness of the vaccines against these *** purpose of this review article is to highlight the current understanding of the immunological mechanisms of the virus and vaccines,as well as to investigate some key variants and mutations of the virus driving the current pandemic and their impacts on current management *** also discussed new technologies being developed for the prevention,treatment,and detection of *** this paper,we thoroughly reviewed and provided crucial information on SARS-CoV-2 virology,vaccines and drugs being used and developed for its prevention and treatment,as well as important variant *** review paper will be beneficial to health care professionals and researchers so they can have a better understanding of the basic sciences,prevention,and clinical treatment of COVID-19 during the *** paper consists of the most updated information that has been available as of June 21,2021.

关键词： severe acute respiratory syndrome coronavirus 2 coronavirus disease 2019 vaccines-variant strains antiviral therapy