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The structural basis of oscillation damping in plant stems-biomechanics and biomimetics

Journal of Bionic Engineering 2004年第3期1卷 149-158页

作者： Hanns-christof Spatz Anton Emanns Olga Speck Competence Network Biomimetics Plant Biomechanics Group Fakultt für Biologie Albert-Ludwigs-Universitt Freiburg Schnzlestr. 1 D –79104 Freiburg GermanyCompetence Network Biomimetics Plant Biomechanics Group Fakultt für BiologieAlbert-Ludwigs-Universitt Freiburg Schnzlestr. 1 D –79104 Freiburg GermanyCompetence Network Biomimetics Plant Biomechanics Group Fakultt für BiologieAlbert-Ludwigs-Universitt Freiburg Schnzlestr. 1 D –79104 Freiburg Germany

Oscillations and their damping were investigated for plant stems of Cyperus alternifolius L., Equisetum hyemale L., Equisetum fluviatile L., Juncus effuses L., Stipa gigantea Link, and Thamnocalamus spathaceus (Franch.) Soderstr. With the exception of T. spathaceus, mechanical damping of the oscillation of individual plant stems, even without side organs, leaves or inflorescences, is quite effective. Our experiments support the hypothesis that embedding stiff sclerenchymatous elements in a more compliant parenchymatous matrix provides the structural basis for the dissipation of mechanical energy in the plant stem. As an application the naturally occurring structures were mimicked in a compound material made from hemp fabrics em- bedded in polyurethane foam, cured under pressure. Like its natural model it shows plastic deformability and viscoelastic be- haviour. In particular the material is characterized by a remarkably high shock absorption capacity even for high impact loads.

关键词： biomechanics biomimetics compound materials damped oscillations plants shock absorption viscoelasticity.

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Polarity,intramolecular charge transfer,and hydrogen bond comediated solvent effects on the optical properties of graphene quantum dots

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Nano research 2023年第1期16卷 45-52页

作者： Yalei Hu christof Neumann Lena Scholtz Andrey Turchanin Ute resch-Genger Siegfried Eigler Institute of Chemistry and Biochemistry Freie Universität BerlinTakustraße 314195 BerlinGermany Institute of Physical Chemistry and Abbe Center of Photonics Friedrich Schiller University JenaLessingstraße 1007743 JenaGermany Federal Institute for Materials research and Testing(BAM) Division BiophotonicsRichard Willstätter Straße 1112489 BerlinGermany

Graphene quantum dots(GQDs)have attracted increasing attention due to their favorable optical properties and have been widely used,e.g.,in the biomedical ***,the properties related to the chemical structure of GQDs,resulting in solventdependent optical properties,still remain ***,we present the synthesis of long-wavelength emitting GQDs with a size of about 3.6 nm via a solvothermal method using oxo-functionalized graphene(oxo-G)and p-phenylenediamine as precursors and their structural and surface chemical analysis by transmission electron and atomic force microscopy(TEM;AFM)as well as Fourier-transform infrared,raman,and X-ray photoelectron spectroscopy(FTIr;raman;XPS).Subsequently,the influence of solvent polarity and proticity on the optical properties of the as-prepared GQDs bearing–OH,–NH_(2),–COOH and pyridine surface groups was *** on the results of the absorption and fluorescence(FL)studies,a possible luminescence mechanism is *** observed solvent-induced changes in the spectral position of the FL maximum,FL quantum yield,and FL decay kinetics in protic and aprotic solvents of low and high polarity are ascribed to a combination of polarity effects,intramolecular charge transfer(ICT)processes,and hydrogen ***,the potential of GQDs for the optical sensing of trace amount of water was *** results of our systematic spectroscopic study will promote the rational design of GQDs and shed more light on the FL mechanism of carbon-based fluorescent nanomaterials.

关键词： graphene quantum dots(GQDs) polarity intramolecular charge transfer(ICT) hydrogen bond optical properties

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Believing processes during the COVID-19 pandemic in individuals with bipolar disorder:An exploratory study

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World Journal of Psychiatry 2022年第7期12卷 929-943页

作者： Sophie Tietz Jolana Wagner-Skacel Hans-Ferdinand Angel Michaela ratzenhofer Frederike T Fellendorf Eva Fleischmann christof Körner Eva Z reininghaus rüdiger J Seitz Nina Dalkner Institute of Psychology University of GrazGraz 8010Austria Department of Psychiatry and Psychotherapeutic Medicine Medical University of GrazGraz 8036Austria Department of Medical Psychology and Psychotherapy Medical University of GrazGraz 8036Austria Department of Catechetics and religious Education University of GrazGraz 8010Austria Department of Neurology Centre of Neurology and Neuropsychiatry Heinrich-Heine-University DüsseldorfMedical FacultyDüsseldorf D-40629Germany

BACKGrOUND Believing or“credition”refers to psychological processes that integrate the cognitions and emotions that influence our *** the credition model by Angel and Seitz,four parameters are postulated:proposition,certainty,emotion and *** is assumed that believing processes are influenced by both the individual as well as socio-cultural factors and external *** or environmental circumstances can include threatening situations such as the ongoing *** has been hypothesized that believing processes related to the pandemic differ between individuals with bipolar disorder(BD)and healthy controls(HC).AIM To investigate credition in individuals with BD during the coronavirus disease 2019(COVID-19)*** Psychiatrically stable individuals with BD(n=52)and age-and sex matched HC(n=52)participated in an online survey during the first lockdown of the COVID-19 *** survey took place between April 9^(th) and June 4^(th),2020,in *** completed the Brief Symptom Inventory-18,the Beck Depression Inventory-Ⅱ,the Altman Self-rating Mania Scale,the Pittsburgh Sleep Quality Index and a dedicated Believing Questionnaire assessing four parameters of credition(proposition,certainty,emotion and mightiness).The MAXQDA software was used to analyze the qualitative *** analyses included analyses of variance,a multivariate analysis of variance and a multivariate analysis of *** Individuals with BD reported significantly more negative propositions[F(1,102)=8.89,P=0.004,η2 p=0.08]and negative emotions[Welch´s F(1,82.46)=18.23,Pre positive propositions[F(1,102)=7.78,P=0.006,η2 p=0.07]and emotions[F(1,102)=14.31,Pr incongruence between their propositions and their emotions[F(1,102)=9.42,P=0.003,η2 p=0.08]and showed strong correlations between the parameters of the Believing Que

关键词： COVID-19 Bipolar disorder Cognition Emotions Judgement Evaluation study

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State of the Art and Future Trends of Unconventional PD-Measurement at Power Transformers

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Journal of Energy and Power Engineering 2014年第6期8卷 1093-1098页

作者： Jurgen Fabian Martin Neuwersch christof Sumereder Michael Muhr robert Schwarz Institute of Automotive Engineering Graz University of Technology Graz 8010 Austria KELAG--Kgtrntner Elektrizitgtts-Aktiengesellschafi KNG Kgtrnten Netz GmbH Klagenfurt 9020 Austria Institute of High Voltage Engineering and System Management Graz University of Technology Graz 8010 Austria r&D Department Siemens Transformers Austria GmbH & Co KG Weiz 8160 Austria

This paper discusses the current state of the art of diagnostics at power transformers. A special focus is set on the UHF-PD-measurement （ultra-high-frequency partial discharge measurement） because at power transformers, this diagnostic method has become more important in recent years. The current state, basics and principles of operations, proceedings as well as advantages of PD-measurement methods are covered. Furthermore problems and proposed solutions are discussed. Bushings and tap changers are not discussed in detail. In many cases, one single diagnostic method does not have the ability to sufficiently evaluate a power transformer. Therefore, a variety of diagnostic methods came up over times, which are commonly used by now. To expand the evaluation opportunities of power transformers, science strives to develop new diagnostic methods as well as to improve the existing ones. Furthermore, environmentally friendly and hardly inflammable ester liquids are examined for the use at power transformers and PD-measurement at HVDC （high voltage direct current） converter transformers as well. Potential diagnostic options and respectively current developments and findings in the field of oil-paper-insulation systems are outlined conclusively.

关键词： Power transformer unconventional PD-measurement UHF-PD-measurement environmentally friendly alternativeinsulating liquids HVDC converter transformer.

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SArISTU:Adaptive Trailing Edge Device(ATED)design process review

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Chinese Journal of Aeronautics 2021年第7期34卷 187-210页

作者： A.CONCILIO I.DIMINO r.PECOrA Department of Adaptive Structures The Italian Aerospace Research Center(CIRA)via MaiorisesncCapua 81034Italia Department of Industrial Engineering Universita`di Napoli‘‘Federico II”Napoli 80138Italia

SArISTU was a big cooperation project granted by the European Commission,7th Framework Programme,carried out between 2011 and *** dealt with smart aeronautic structures,both morphing and sensored;its main target was to demonstrate the feasibility of designing,manufacturing and operating in representative environment,instrumented *** now,it represents the major effort carried out within the European Union on the development of adaptive architectures for air *** that big activity,the realization of an Adaptive Trailing Edge Device(ATED)for wing camber adaptations aimed at compensating the weight reduction following the fuel consumption during cruise was *** made the core of investigations target variable geometry aircraft components together with two other analyses concerning the development of shape-changing winglet and droop *** activities were conducted by the Italian Aerospace research Centre(CIrA)in tight cooperation with the University of Napoli,"Federico II",who coordinated a group of 12 different partners from 8 different nations(France,Germany,Greece,the Netherlands,Israel,Spain,Turkey,and Italy).In this paper,an integral synthesis of that work is reported,with a focus on the definition and realization of the components of the presented *** publication is in fact meant as the first part of a series that is aimed at overviewing the whole adaptive trailing edge development,till wind tunnel tests *** a concise report is a critical and harmonized review of what have been performed by many colleagues spread all over Europe,all of which are duly recalled in the reported bibliography where the reader may access more detailed information and *** detail,the paper starts with a general introduction of the concept and its aims,to move to the specs definition immediately ***,it deals with a short but comprehensive description of the main ATED components:structural skeleton,skin,actuation and s

关键词： Actuator network Aeroelasticity Adaptive structures Adaptive systems design Adaptive trailing edge Kinematic systems Morphing SArISTU Sensor network Skins

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利用计算全息片的锥面干涉检验

利用计算全息片的锥面干涉检验

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中国光学学会2011年学术大会

作者：马骏朱日宏高志山 christof Pruss Matthias Hfner 袁操今 Wolfgang Osten 南京理工大学电子工程与光电技术学院 Institut für Technische Optik Universitt StuttgartPfaffenwaldring 9Stuttgart70569Germany

高精度线性锥面在现代光学系统设计中得到越来越广泛的关注和应用。但是由于其面形的特殊性,传统手段难以实现检测目的,尤其对于锥角比较小的待测锥面。在传统的干涉检测系统上,使用计算全息片（CGH）及相关技术可以实现非球面甚至自由... 详细信息

高精度线性锥面在现代光学系统设计中得到越来越广泛的关注和应用。但是由于其面形的特殊性,传统手段难以实现检测目的,尤其对于锥角比较小的待测锥面。在传统的干涉检测系统上,使用计算全息片（CGH）及相关技术可以实现非球面甚至自由曲面的高精度检测。本文介绍一种在平面干涉系统利用高频CGH实现对锥面检测的方法。在分析过程中,利用锥面像差多项式作为工具,提取待测锥面的锥角误差,并结合错位绝对检验技术完成待测锥面的绝对检验。

关键词：干涉检验锥面计算全息

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