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Journal of Magnesium and Alloys 2021年第1期9卷 112-122页

作者： bjorn wiese Regine Willumeit-Römer Dietmar Letzig Jan Bohlen Division Metallic Biomaterials Institute of Materials ResearchHelmholtz-Zentrum GeesthachtMax-Planck-Str.1Geesthacht 21502Germany Magnesium Innovation Center(MagIC) Institute of Materials ResearchHelmholtz-Zentrum GeesthachtMax-Planck-Str.1Geesthacht 21502Germany

The effect of Ag in solid solution on the microstructure,texture and the deformation behaviour of indirectly extruded Mg was *** as a solid solution strengthener affects the behaviour during extrusion,resulting in enhanced deformation related heating and corresponding coarser grained *** substantial effect on the texture development is *** mechanical properties simultaneously increase in stress and strain levels with increasing Ag content,especially in tension as a result of the changing impact of the slip modes which can be associated with a decrease of the lattice parameters as well as the c/a ratio of the hcp lattice *** compression tests with twin dominated flow,the impact is much smaller on the compressive yield stress but higher with respect to the twinning related strain hardening *** solution strength functions for Fleischer and Labusch were determined,also confirming the anisotropic behaviour of the extruded Mg alloys.

关键词： Mg-Ag-alloys Lattice parameters Indirect extrusion Microstructure Mechanical properties

Deteriorated corrosion performance of micro-alloyed Mg-Zn alloy after heat treatment and mechanical processing

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Journal of Materials Science & Technology 2021年第33期92卷 214-224页

作者： Yiming Jin Carsten Blawert Hong Yang bjorn wiese Jan Bohlen Di Mei Min Deng Frank Feyerabend Regine Willumeit Division of Metallic Biomaterials Helmholtz-Zentrum Geesthacht21502 GeesthachtGermany Southwest Technology and Engineering Research Institute 400039 ChongqingChina Magnesium Innovation Center Helmholtz-Zentrum Geesthacht21502 GeesthachtGermany State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing400044China National Engineering Research Center for Magnesium Alloys Chongqing University400044 ChongqingChina Faculty of Engineering Christian-Albrechts-Universität zu Kiel24143 KielGermany

The corrosion performances of the as-cast and solution-treated Mg-0.5Zn samples were investigated in 0.9%Na Cl solution and *** the electrochemical measurement results and corrosion morphology observations,it is found that the corrosion resistance of Mg-0.5Zn deteriorated with the extension of solution treatment *** main reason was the formation of Fe-Si precipitates with higher Fe concentrations during heat *** Fe-Si precipitates,especially the ones with high Fe contents influenced the corrosion initiation and propagation *** regard of corrosion performance,the solution-treated and then extruded sample was also performing not as good as the cast and then directly extruded sample.

关键词： Magnesium Alloy Internetallics SEM Inclusions Corrosion

High-resolution ex vivo analysis of the degradation and osseointegration of Mg-xGd implant screws in 3D

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Bioactive Materials 2022年第7期7卷 37-52页

作者： Diana Krüger Silvia Galli Berit Zeller-Plumhoff D.C.Florian Wieland Niccolo Peruzzi bjorn wiese Philipp Heuser Julian Moosmann Ann Wennerberg Regine Willumeit-Romer Institute of Metallic Biomaterials Helmholtz-Zentrum HereonMax-Planck-Str.1Geesthacht21502Germany University of Malmo Faculty of OdontologyDepartment of ProsthodonticsCarl Gustafs vag 34Klerken20506MalmoSweden Lund University Department of Clinical Sciences LundMedical Radiation PhysicsBarngatan 422242LundSweden Deutsches Elektronen-Synchrotron(DESY) Notkestrasse 8522607HamburgGermany Institute of Materials Physics Helmholtz-Zentrum HereonMax-Planck-Str.1Geesthacht21502Germany University of Gothenburg Institute of OdontologyDepartment of ProsthodonticsMedicinaregatan 12 f41390GoteborgSweden

Biodegradable magnesium(Mg)alloys can revolutionize osteosynthesis,because they have mechanical properties similar to those of the bone,and degrade over time,avoiding the need of removal ***,they are not yet routinely applied because their degradation behavior is not fully *** this study we have investigated and quantified the degradation and osseointegration behavior of two biodegradable Mg alloys based on gadolinium(Gd)at high ***-5Gd and Mg-10Gd screws were inserted in rat tibia for 4,8 and 12 ***,the degradation rate and degradation homogeneity,as well as bone-to-implant interface,were studied with synchrotron radiation micro computed tomography and ***(Ti)and polyether ether ketone(PEEK)were used as controls material to evaluate *** results showed that Mg-5Gd degraded faster and less homogeneously than *** alloys gradually form a stable degradation layer at the interface and were surrounded by new bone *** results were correlated to in vitro data obtained from the same material and *** average bone-to-implant contact of the Mg-xGd implants was comparable to that of Ti and higher than for *** results suggest that both Mg-xGd alloys are suitable as materials for bone implants.

关键词： Magnesium alloys Biodegradable implant Micro-computed tomography degradation rate Degradation homogeneity Ex vivo imaging Ex vivo histology Histology vs.tomography

Impacts of CO2 and H2S on the risk of hydrate formation during pipeline transport of natural gas

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Frontiers of Chemical Science and Engineering 2019年第3期13卷 616-627页

作者： Solomon A. Aromada bjorn Kvamme Department of Physics and Technology University of Bergen5007 BergenNorway Strategic Carbon LLC Vestre Holbergsallmenningen 175011 BergenNorway

Evaluation of maximum content of water in natural gas before water condenses out at a given temperature and pressure is the initial step in hydrate risk analysis during pipeline transport of natural gas, The impacts of CO2 and ELS in natural gas on the maximum mole-fractions of water that can be tolerated during pipeline transport without the risk of hydrate nucleation has been studied using our novel thermodynamic scheme. Troll gas from the North Sea is used as a reference ease, it contains very negligible amount of CO2 and no H2S. Varying mole-fractions of CO2 and INS were introduced into the Troll gas, and the effects these inorganic impurities on the water tolerance of the system were evaluated. It is observed that CO2 does not cause any distinguishable impact on water tolerance of the system, but H2S does. Water tolerance decreases with increase in concentration of H2S. The impact of ethane on the system was also investigated. The maximum mole-fraction of water permitted in the gas to ensure prevention of hydrate formation also decreases with increase in the concentration of C2H6 like H2S. H2S has the most impact, it tolerates the least amount of water among the components studied.

关键词： hydrate hydrogen Sulphide CO2 dewpoint pipeline

Interleukin 4-induced neuroprotection and regulation of microglia activation as a therapeutic approach in the MPTP model of Parkinson's disease

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Neural Regeneration Research 2017年第9期12卷 1433-1434页

作者： bjorn Spittau Institute for Anatomy and Cell Biology Department of Molecular Embryology Faculty of Medicine University of Freiburg Institute of Anatomy University of Rostock

Parkinson＇s disease （PD） has been described as one of the most common neurodegenerative diseases affecting up to 2% of the worldwide population over 60 years of age. The hallmarks of PD are progressive loss of midbrain dopaminergic （mDA） neurons and a decrease in striatal dopamine levels, which result in typ- ical clinical motor symptoms such as akinesia, resting tremor, rigidity, and gait impairments. Although the causes for PD are only partially understood and seem to be very heterogeneous, one of the common phenomenons observed in toxin-based an- imal models of PD as well as PD patients is a microglia-driven neuroinflammatory response,

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Hierarchical approach for fatigue cracking performance evaluation in asphalt pavements

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Frontiers of Structural and Civil Engineering 2017年第3期11卷 257-269页

作者： Ibrahim ONIFADE Yared DINEGDAE bjorn BIRGISSON Department of Civil and Architectural Engineering KTH Royal Institute of Technology Stockholm Sweden School of Engineering and Applied Science Aston University Aston Triangle Birmingham B4 7ET United Kingdom

In this paper, a hierarchical approach is proposed for the evaluation of fatigue cracking in asphalt concrete pavements considering three different levels of complexities in the representation of the material behaviour, design parameters characterization and the determination of the pavement response as well as damage computation. Based on the developed hierarchical approach, three damage computation levels are identified and proposed. The levels of fatigue damage analysis provides pavement engineers a variety of tools that can be used for pavement analysis depending on the availability of data, required level of prediction accuracy and computational power at their disposal. The hierarchical approach also provides a systematic approach for the understanding of the fundamental mechanisms of pavement deterioration, the elimination of the empiricism associated with pavement design today and the transition towards the use of sound principles of mechanics in pavement analysis and design.

关键词： fatigue cracking energy based crack initiation mechanistic approach pavement analysis

Taking Comfort in Points:The Appeal of the Norwegian Model in Sweden

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Journal of Data and Information Science 2018年第4期3卷 85-95页

作者： bjorn Hammarfelt Swedish School of Library and In formation Science University of BorasSweden

Purpose: The "Norwegian model" has become widely used for assessment and resource allocation purposes. This paper investigates why this model has becomes so widespread and influential. Approach: A theoretical background is outlined in which the reduction of "uncertainty" is highlighted as a key feature of performance measurement systems. These theories are then drawn upon when revisiting previous studies of the Norwegian model, its use, and reactions to it, in ***: The empirical examples, which concern more formal use on the level of universities as well as responses from individual researchers, shows how particular parts—especially the "publication indicator"—are employed in Swedish academia. The discussion posits that the attractiveness of the Norwegian model largely can be explained by its ability to reduce complexity and uncertainty, even in fields where traditional bibliometric measurement is less applicable. Research limitations: The findings presented should be regarded as examples that can be used for discussion, but one should be careful to interpret these as representative for broader sentiments and ***: The sheer popularity of the Norwegian model, leading to its application in contexts for which it was not designed, can be seen as a major challenge for the ***: This paper offers a novel perspective on the Norwegian model by focusing on its general "appeal", rather than on its design, use or(mis)-use.

关键词： The Norwegian model Sweden Uncertainty Bibliometric indicators Assessment systems

Evaluation of Turbulence Models in Predicting Hypersonic and Subsonic Base Flows Using Grid Adaptation Techniques

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Chinese Journal of Aeronautics 2012年第3期25卷 325-334页

作者： YOU Yancheng BUANGA bjorn HANNEMANN Volker LUDEKE Heinrich Institute of Aerodynamics and Flow Technology German Aerospace Center (DLR) Braunschweig 38108 Germam Institute of Aerodynamics and Flow Technology German Aerospace Center (DLR) Gottingen 37073 Germany Department of Aeronautics Xiamen University Xiamen 361005 China

The flows behind the base of a generic rocket, at both hypersonic and subsonic flow conditions, are numerically studied. The main concerns are addressed to the evaluation of turbulence models and the using of grid adaptation techniques. The investigation focuses on two configurations, related to hypersonic and subsonic experiments. The applicability tests of different turbu- lence models are conducted on the level of two-equation models calculating the steady state solution of the Reynolds-averaged Navier-Stokes（RANS） equations. All used models, the original Wilcox k-co, the Menter shear-stress transport （SST） and the ex- plicit algebraic Reynolds stress model（EARSM） formulation, predict an asymmetric base flow in both cases caused by the support of the models. A comparison with preliminary experimental results indicates a preference for the SST and EARSM results over the results from the older k-co model. Sensitivity studies show no significant influence of the grid topology or the location of the laminar to turbulent transition on the base flow field, but a strong influence of even small angles of attack is reported from the related experiments.

关键词： base flows turbulence models steady calculation grid adaptation numerical simulation

Environmentally Adapted Hydropower in Sweden

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Small Hydro Power News 2006年第1期23卷 19-24页

作者： bjorn Svensson SwedPower AB Sweden

IntroductionThe alteration of watercourses has been extensive in Sweden as well as in other industrialised countries. Since the end of the last century the water table of about 2500 lakes have been lowered in order to reclaim farmland. More than 600 of these have been completely drained. This particular activity came to a halt at the end of the 1950s whereas the ditching of wetlands and dredging and channelisation of watercourses for the benefit of forestry are still ongoing activities. The regulation of rivers for the purpose of meeting differential needs of hydroelectric power commenced in the beginning of this century, At that time, the floating of timber constituted the economically most important profit from exploitation of northern Swedish rivers.

关键词：瑞典小水电水电站水资源

Historical Bibliometrics Using Google Scholar: The Case of Roman Law, 1727–2016

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Journal of Data and Information Science 2020年第3期5卷 18-32页

作者： Janne Polonen bjorn Hammarfelt Federation of Finnish Learned Societies Snellmaninkatu 1300170 HelsinkiFinland Swedish School of Library and Information Science University of BorasAllegatan 1Boras50332Sweden

Purpose: The purpose of this study is to investigate the historical and linguistic coverage of Google Scholar, using publications in the field of Roman law as an ***/methodology/approach: To create a dataset of Roman law publications, we retrieved a total of 21,300 records of publications, published between years 1500 and 2016, with title including words denoting "Roman law" in English, French, German, Italian, and Spanish. Findings: We were able to find publications dating back to 1727. The largest number of publications and authors date to the late 19th century, and this peak might be explained by the role of Roman law in French legal education at the time. Furthermore, we found exceptionally skewed concentration of publications to authors, as well as of citations to publications. We speculate that this could be explained by the long time-frame of the study, and the importance of classic works. Research limitation: Major limitations, and potential future work, relate to data quality, and cleaning, disambiguation of publications and authors, as well as comparing coverage with other data sources. Practical implications: We find Google Scholar to be a promising data source for historical bibliometrics. This approach may help bridge the gap between bibliometrics and the "digital humanities".Originality/value: Earlier studies have focused mainly on Google Scholar's coverage of publications and citations in general, or in specific fields. The historical coverage has, however, received less attention.

关键词： Historical bibliometrics Google Scholar Roman law