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The magic mirror of M.C. Escher

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The magic mirror of M.C. Escher

Tapping the tree-ring archive for studying effects of resin extraction on the growth and climate sensitivity of Scots pine

作者： Bruno ernst.

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Forest Ecosystems 2017年第3期4卷 167-173页

作者： ernst van der Maaten Annemarie Mehl Martin Wilmking Marieke van der Maaten-Theunissen Institute of Botany and Landscape Ecology University of Greifswald

Background： In the German Democratic Republic（GDR）, resin tapping in Scots pine（Pinus sylvestris L.） forests was a major economic activity, and resin-tapped stands are frequently found up until this day. In this study, we investigate how the mechanical damage caused by resin tapping affects the growth and climate sensitivity of Scots pine using a dendroecological ***： Tree-ring samples were collected from resin-tapped and non-tapped trees in two forest areas in northeastern Germany, and tree-growth patterns were analyzed. For elucidating effects of resin tapping on the climate sensitivity of pine growth, climate-growth relationships and pointer years were ***： We observed that resin tapping positively affects tree growth at breast height, likely as wood formation is concentrated on the living part of the bole（i.e. after tapping there is no growth taking place on the tapping face due to the mechanical damage done to the cambium）. We observed no differences in the climate sensitivity of tapped and non-tapped trees, nor in the occurrence of extreme growth ***： Our results highlight that resin extraction is, apart from inflicting mechanical damage, not altering the sensitivity of Scots pine growth to climatic conditions.

关键词： Climate-growth relationships Dendroecology Mechanical damage

A holistic approach for the investigation of lining response to mechanized tunneling induced construction loadings

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Underground Space 2018年第1期3卷 45-60页

作者： Vojtech ernst Gall Ahmed Marwan Mario Smarslik Markus Obel Peter Mark Gunther Meschke Inustitute for Structural Mechanics Ruhr University BochumBochunGermany Institute of Concrete Structures Ruhr University BochumBochumGermany

Design methods for segmental tunnel linings used in mechanized tunnel constructions typically employ numerical bedded beam mod-els and/or classical analytical solutions for the determination of structural forces(*** and shear and axial forces)and simple load spreading assumptions for the design of the reinforcement in joint *** effcient such methods may be,many physical details are often overlooked and/or oversimpliﬁed in the process of reducing the actual structure to a structural beam model,***-lytically derived loadings are employed,the grouting and ground reactions are reduced to a spring bedding,and the conﬁnement due to grouting at the longitudinal joint is largely not considered in reinforcement *** a design process is not able to account for,or predict,the susceptibility of tunnel linings to often observed damages that,although they may not be structurally relevant,lead to ser-viceability or durability issues,such as crack development or chipping at the segment *** methods,such as the Finite Element Method,provide an opportunity to model the segmental tunnel lining and its response to the entire TBM construction process and to explicitly model the crack development within individual segments using modern methods to model the discontinuities in *** this contribution,a holistic modeling procedure for the representation of the tunnel lining within the tunneling process is pro-posed and compared to traditional lining models.A 3D process oriented Finite Element model is used to calculate the predicted forces on the tunnel lining and the obtained results are compared with those generated by traditional ***,the predicted defor-mations are then transferred to a detailed segment model in which the nonlinear response of the segment at the longitudinal joint is mod-eled using an interface element based approach to simulate concrete cracking.

关键词： Mechanized tunneling Segmental tunnel linings Finite element method

Helium droplet assisted synthesis of plasmonic Ag@ZnO core@shell nanoparticles

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Nano Research 2020年第11期13卷 2979-2986页

作者： Alexander Schiffmann Thomas Jauk Daniel Knez Harald Fitzek Ferdinand Hofer Florian Lackner Wolfgang E.ernst Institute of Experimental Physics Graz University of TechnologyA-8010GrazAustria Institute of Electron Microscopy and Nanoanalysis&Graz Centre for Electron Microscopy Graz University of TechnologyA-8010GrazAustria

Plasmonic Ag@ZnO core@shell nanoparticles are formed by synthesis inside helium droplets with subsequent deposition and controlled *** particle size and shape can be controlled from spherical sub-10 nm particles to larger elongated *** advantage of the method is the complete absence of solvents,precursors,and other chemical *** obtained particle morphology and elemental composition have been analyzed by scanning transmission electron microscopy(STEM)and energy dispersive X-ray spectroscopy(EDS).The results reveal that the produced particles form a closed and homogeneous ZnO layer around a 2–3 nm Ag core with a uniform thickness of(1.33±0.15)nm and(1.63±0.31)nm for spherical and wire-like particles,*** results are supported by ultraviolet photoelectron spectroscopy(UPS),which indicates a fully oxidized shell layer for the particles studied by *** plasmonic properties of the produced spherical Ag@ZnO core@shell particles are investigated by two-photon photoelectron(2PPE)*** excitation of the localized surface plasmon resonance in Ag at around 3 eV,plasmonic enhancement leads to the liberation of electrons with high kinetic *** is observed for both Ag and Ag@ZnO particles,showing that even if a Ag cluster is covered by the ZnO layer,a plasmonic enhancement can be observed by photoelectron spectroscopy.

关键词： nanoparticle helium droplet plasmonics photoelectrons

Temperature effect on the dynamic adsorption of anionic surfactants and alkalis to silica surfaces

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Petroleum Science 2022年第4期19卷 1866-1876页

作者： Marco Masulli Zi-Long Liu Feng-Zhi Guo Xue Li ernst J.RSudholter Naveen Kumar Bejing Key Laboratory of Optical Detection Technology for Oil and Gas China University of Petroleum-BejingBeijing102249PR China Organic Materials&Interfaces Department of Chemical EngineeringFaculty of Applied SciencesDelft University of TechnologyVan der Maasweg92629DelftHZthe Netherlands

Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR). Here, we investigated the adsorption behaviors of anionic surfactants and alkalis on silica for the first time as a function of temperature using quartz crystal microbalance with dissipation(QCM-D). The results demonstrated that the temperature dependent critical micelle concentration of alcohol alkoxy sulfate(AAS) surfactant can be quantitatively described by the thermodynamics parameters of micellization, showing a mainly entropy-driven process. AAS adsorption was mediated under varying temperature conditions, by divalent cations for bridging effect, monovalent cations competitive for adsorption sites but not giving cation bridging, pH regulation of deprotonated sites of silica, presence of alkoxy groups in the surfactants, and synergistic effect of surfactant coinjection. The addition of organic alkalis can enhance the overall adsorption of the species with AAS,whereas inorganic alkali of Na_(2)CO_(3) had capability of the sequestration of the divalent ions, whose addition would reduce AAS adsorption. The typical AAS adsorption indicated a non-rigid multilayer,estimated to have between 2 and 5 layers, with a likely compact bilayer followed by disorganized and unstable further layering. The new fundamental understanding about temperature effect on surfactants and alkalis adsorption contributes to optimizing the flooding conditions of chemicals and developing more efficient mitigation strategies.

关键词： Temperature Surfactant Alkali Adsorption Enhanced oil recovery

Cellular and molecular mechanisms breaking immune tolerance in inborn errors of immunity

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Cellular & Molecular Immunology 2021年第5期18卷 1122-1140页

作者： Georgios Sogkas Faranaz Atschekzei Ignatius Ryan Adriawan Natalia Dubrowinskaja Torsten Witte Reinhold ernst Schmidt Department of Rheumatology and Immunology Hannover Medical SchoolHanoverGermany Hannover Medical School Cluster of Excellence RESIST(EXC 2155)HanoverGermany

In addition to susceptibility to infections,conventional primary immunodeficiency disorders(PIDs)and inborn errors of immunity(IEI)can cause immune dysregulation,manifesting as lymphoproliferative and/or autoimmune *** can be the prominent phenotype of PIDs and commonly includes cytopenias and rheumatological diseases,such as arthritis,systemic lupus erythematosus(SLE),and Sjogren’s syndrome(SjS).Recent advances in understanding the genetic basis of systemic autoimmune diseases and PIDs suggest an at least partially shared genetic background and therefore common pathogenic ***,we explore the interconnected pathogenic pathways of autoimmunity and primary immunodeficiency,highlighting the mechanisms breaking the different layers of immune tolerance to self-antigens in selected IEI.

关键词： Inborn errors of immunity Primary immunodeficiencies Autoimmunity Rheumatic diseases

Black Silicon nanostructures on silicon thin films prepared by reactive ion etching

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Chinese Optics Letters 2013年第13期11卷 127-129页

作者： Martin Steglich Thomas Kasebier Ingmar Hoger Kevin Fuchsel Andreas Tiinnermann ernst-Bernhard Kley Institute of Applied Physics A bbe Center of Photonics Friedrich Schiller University Jena Albert-Einstein-Str. 15 07745 Jena Germany Institute of Photonic Technology Albert-Einstein-Str. 9 07745 Jena Germany

In this letter, the application of dry etching to thin films on glass is described. The utilized （ICP-RIE） of SF6 and 02 is discussed and a demonstrated. prepare Black Silicon nanostructures on crystalline silicon reactive ion etching with an inductively coupled plasma remarkable increase in light absorption of about 70% is demonstrated.

关键词： Reactive ion etching

IL-1β limits the extent of human 6-sulfo LacNAc dendritic cell (slanDC)-mediated NK cell activation and regulates CD95-induced apoptosis

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Cellular & Molecular Immunology 2017年第12期14卷 976-985页

作者： Dejene Milkessa Tufa Fareed Ahmad Debanjana Chatterjee Gerrit Ahrenstorf Reinhold ernst Schmidt Roland Jacobs Department of Clinical Immunology and Rheumatology Hannover Medical School30625 HannoverGermany

To function optimally,human blood natural killer(NK)cells need to communicate with other immune ***,it has been shown that NK cells communicate with 6-sulfo LacNAc dendritic cells(slanDCs),which are able to stimulate NK cells in *** this study,we investigated how slanDCs regulate the level of NK cell *** secretion of interleukin(IL)-1βby slanDCs during coculture with NK cells increased as a result of signaling via intercellular adhesion molecule-1 on slanDCs following its interaction with lymphocyte functionassociated antigen-1 on NK ***-1βinduced the expression of Fas receptor(CD95)on NK *** binding of Fas ligand(CD178)to CD95 induced the apoptosis of activated NK ***,IL-1βalso induced increased cyclooxygenase-2 expression in slanDCs,which in turn enabled the cells to secrete prostaglandin(PG)-***,PGE2 acted as a suppressing agent,tuning down the activation level of NK *** summary,IL-1βlimits the level of NK cell activation by inducing apoptosis and suppression as a homeostatic regulatory function.

关键词： COX-2 Fas-induced apoptosis immunosuppression NK cells slanDCs

SINO-GERMAN WORKSHOP ON CHEMICAL AND PHYSICAL INTERACTIONS BETWEEN PARTICLES AND FLUIDS

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China Particuology 2005年第1期3卷 145-150页

作者： JoachimWerther WeiGe ernst-UlrichHartge JinghaiLi WeiWang DepartmentofChemicalEngineeringI TechnicalUniversityHamburg-HarburgHamburg21071Germany InstituteofProcessEngineering ChineseAcademyofSciencesBeijing100080P.R.China

1. Introduction Supported by the Sino-German Center for Research Promotion, and organized jointly by the National Natural Science Foundation of China (NSFC) and the German Research Foundation (DFG), the third Sino-German workshop on particle fluid systems was held on Oct. 24-31, 2004 in Beijing, China, following the two previous successful workshops held on Aug. 30-31,1999 in Hamburg, Germany (Li and Werther, Chem. Eng. Technol., 23(4), 378, 2000) and May 18-19, 2001 in Beijing, China (Li, Ge, Werther and Bruhns, Chem. Eng. Technol., 24(11), 1097, 2001). Thirty-one scientists from China, Germany, Japan and The Netherlands came together for interdisciplinary discussion over the core problem of multi-phase reaction systems in the name of "Chemical and Physical Interactions between Particles and Fluids".

关键词： EMMS SINO-GERMAN WORKSHOP ON CHEMICAL AND PHYSICAL INTERACTIONS BETWEEN PARTICLES AND FLUIDS