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Nano Research 2011年第4期4卷 414-424页

作者： christian Reitz christian Suchomski Christoph Weidmann Torsten Brezesinski Institute of Physical Chemistry Justus-Liebig-University Giessen Giessen 35392 Germany

Herein is reported the soft-templating synthesis of visible-light photoactive bismuth ferrite （BiFeO3） nanoarchitectures in the form of thin fihns using a poly（ethylene-co-butylene）-block-poly（ethylene oxide） diblock copolymer as the structure-directing agent. We establish that （1） the self-assembled materials employed in this work are highly crystalline after annealing at 550 ℃ in air and that （2） neither the bismuth-poor Bi2Fe4O9 phase nor other impurity phases are formed. We further show that there is a distinct restructuring of the high quality cubic pore network of amorphous BiFeO3 during crystallization. This restructuring leads to films with a unique architecture that is composed of anisotropic crystallites intermingled with a continuous mesoporosity. While this article focuses on the characterization of these novel materials by electron microscopy, krypton physisorption, grazing incidence small-angle X-ray scattering, time-of-flight secondary ion mass spectrometry, X-ray photoelectron spectroscopy, UV-vis and Raman spectroscopy, we also examine the photocatalytic properties and show the benefits of the combination of mesoporosity and nanocrystallinity. Templated BiFeO3 thin films （25% porosity） with a direct optical band gap at 2.9 eV exhibit a catalytic activity for the degradation of rhodamine B much better than that of nontemplated samples. We attribute this improvement to the nanoscale porosity, which provides for more available active sites on the photocatalyst.

关键词： Self-assembly mesoporous nanocrystalline thin films photocatalysis multiferroic

Gust response of an elasto-flexible morphing wing using fluid–structure interaction simulations

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Chinese Journal of Aeronautics 2024年第2期37卷 45-57页

作者： Jonathan PFLÜGER christian BREITSAMTER Department of Mechanical Engineering Technical University of MunichGarching 85748Germany

Small and micro unmanned aircraft are the focus of scientific interest due to their wide range of *** often operate in a highly unstable flight environment where the application of new morphing wing technologies offers the opportunity to improve flight *** investigated concept comprises port and starboard adjustable wings,and an adaptive elastoflexible membrane serves as the lifting *** focus is on the benefits of the deforming membrane during the impact of a one-minus-cosine type *** a low Reynolds number of Re=264000,the morphing wing model is investigated numerically by unsteady fluid-structure interaction ***,the numerical results are validated by experimental data from force and moment,flow field,and deformation ***,with the rigid wing as the baseline,the flexible case is investigated,focusing on the advantages of the elastic *** all configurations studied,the maximum amplitude of the lift coefficient under gust load shows good agreement between the experimental and numerical *** the decay of the gust,they differ more the higher the aspect ratio of the *** considering the flow field,the main differences are due to the separation behavior on the upper side of the *** flow reattaches earlier in the experiments than in the simulations,which explains the higher lift values observed in the *** at one intermediate configuration does the lift amplitude of the rigid configuration exceeds that of the flexible by about 12%,with the elastic membrane resulting in a smaller and more uniform peak load,which is also evident in the wing loading and hence in the root bending moment.

关键词： Membrane wing Morphing wing Flexible wing surface Computational fluid dynam-ics Fluid-structure interaction Unsteady inflow condition Gust response

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在实施的另一边

现代制造 2006年第17期 34-37页

作者： christian.brecher christian Wenzel Andere

超精密加工的监控方案保证了工艺的稳定性以及工件的表面质量和精度。

关键词：超精密加工表面质量监控方案稳定性

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直接与机器人互动的编程系统

现代制造 2014年第20期 66-69页

作者： christian.brecher UND ANDERE

今天，很多生产流程借助工业机器人实现了自动化。在使用中，借助编码控制程序实现工业机器人运动和控制工具的自动化生产流程。

关键词：工业机器人编程系统生产流程编码控制程序实现自动化

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大型部件的精密加工

现代制造 2017年第18期 68-70页

作者： christian.brecher Robert Schmitt

针对大型部件加工的公差范围在低位变动时，达到几个微米。精密加工可以提高诸如涡轮机、船舶和飞机等方面的制造效益，因此也成为发达国家的生产驱动力。对加工精度产生影响的一个主要影响因素便是机床设备和部件的不断变化着的热塑性... 详细信息

针对大型部件加工的公差范围在低位变动时，达到几个微米。精密加工可以提高诸如涡轮机、船舶和飞机等方面的制造效益，因此也成为发达国家的生产驱动力。对加工精度产生影响的一个主要影响因素便是机床设备和部件的不断变化着的热塑性状态。各种不同的内外部热源及其下降都会对机床设备和部件的结构产生影响，例如在加工车间里因新部件送抵而开启车间大门，从而导致机床和部件的温度突降，如果说此类干扰源还可以被规划并可以相当容易地被克服的活，那么诸如加工废热和冷却润滑剂对机床设备和部件外形的影响刚更加复杂。

关键词：大型部件精密加工机床设备加工车间冷却润滑剂公差范围发达国家塑性状态

Transitive partially hyperbolic di eomorphisms with one-dimensional neutral center

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Science China Mathematics 2020年第9期63卷 1647-1670页

作者： christian Bonatti Jinhua Zhang Institut de Mathematiques de Bourgogne Universite de BourgogneDijon 21104France School of Mathematical Sciences Beihang UniversityBeijing 100191China

In this paper,we study transitive partially hyperbolic di eomorphisms with one-dimensional topologically neutral center,meaning that the length of the iterate of small center segments remains *** systems are dynamically *** show that there exists a continuous metric along the center foliation which is invariant under the *** an application,we classify the transitive partially hyperbolic di eomorphisms on 3-manifolds with topologically neutral center.

关键词： partial hyperbolicity dynamical coherence conjugacy transitivity neutral

Barriers and Drivers for Mainstreaming Nature-Based Solutions for Flood Risks: The Case of South Korea

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International Journal of Disaster Risk Science 2021年第5期12卷 661-672页

作者： Sungju Han christian Kuhlicke Department of Urban and Environmental Sociology UFZ—Helmholtz Centre for Environmental Research04318 LeipzigGermany Institute for Environmental Sciences and Geography University of Potsdam14468 Potsdam-Golm.Germany German Centre for Integrative Biodiversity Research(iDiv)Halle-Jena-Leipzig.04103 Leipzig Germany

Nature-based solutions(NBS)are seen as a promising adaptation measure that sustainably deals with diverse societal challenges,while simultaneously delivering multiple ***-based solutions have been highlighted as a resilient and sustainable means of mitigating floods and other hazards *** study examined diverging conceptualizations of NBS,as well as the attitudinal(for example,emotions and beliefs)and contextual(for example,legal and political aspects)barriers and drivers of NBS for flood risks in South *** interviews were conducted with 11 experts and focused on the topic of flood risk measures and NBS case *** analysis found 11 barriers and five drivers in the attitudinal domain,and 13 barriers and two drivers in the contextual *** experts see direct monetary benefits as an important attitudinal factor for the ***,the cost-effectiveness of NBS and their capacity to cope with flood risks were deemed influential factors that could lead decision makers to opt for *** the contextual factors,insufficient systems to integrate NBS in practice and the ideologicalization of NBS policy were found to be peculiar barriers,which hinder consistent realization of initiatives and a long-term national plan for *** the barriers and drivers related to the mainstreaming of NBS is critical if we are to make the most of such solutions for society and *** is also essential that we have a shared definition,expectation,and vision of NBS.

关键词： Climate change Flood risk management Nature-based solutions(NBS) South Korea

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滚珠丝杠热变化对机床精度的影响

现代制造 2015年第7期 22-24页

作者： christian.brecher Marcel Fey

有人预测：切削加工机床的静态和动态性能会越来越好，这样就可以明显的减少它们对加工误差的影响。相反，在总加工偏差中，热变形的影响却越来越大。在过去的几十年中，总加工偏差中，热变形影响的比例提高到了70％～75％。

关键词：机床精度滚珠丝杠热变化加工偏差动态性能加工机床加工误差变形影响

Existence of global solutions to isentropic gas dynamics equations with a source term

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Science China Mathematics 2010年第1期53卷 115-124页

作者： KLINGENBERG christian Institut fr angewandte Mathematik Universitt WrzburgAm Hubland97074 WrzburgGermany

In this paper we prove existence of isentropic gas dynamic equations with a source term (1.2). To this end we construct a sequence of regular hyperbolic systems (1.1) to approximate the inhomogeneous system of isentropic gas dynamics (1.2). First,for each fixed approximation parameter δ and very general condition on P (ρ),we establish the existence of entropy solutions for the Cauchy problem (1.1) with bounded initial date (1.4). Second,letting=o(δ),we obtain a complete proof of the H-1loc compactness of weak entropy pairs of system (1.2) in the form η(ρ,u) =ρH(ρ,u) given in Chen-LeFloch (2003). Finally,for the conditions of P(ρ) given in Chen-LeFloch (2003),applied to the results in Theorems 1 and 2,we obtain the global existence of entropy solutions for the Cauchy problem (1.2) with bounded initial date (1.4).

关键词： isentropic gas dynamics system global entropy solution compactness in H-loc1 compensated compactness method

SYNTHESIS OF CONDUCTIVE POLYANILINE VIA OXIDATION BY MnO_2

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Chinese Journal of Polymer Science 2004年第3期22卷 269-277页

作者：生瑜 christian Carrotc Jacques Guilletc Institute of Materials Science and Engineering East China University of Science and Technology Shanghai 20023 China Laboratoire de Rheologie des Matieres Plastiques FRE CNRS 2396 Universite Jean Monnet 42023 St-Etienne Cedex 2 France

A unique process of chemical oxidation polymerization of aniline using manganese dioxide (MnO2) as the oxidizing agent in an aqueous medium is described. The reaction between aniline and MnO2 follows a mechanism by which the organic monomer is oxidized while the metal oxide undergoes reductive dissolution. The effects of the amount of oxidizing agent and aniline, pH and temperature of the reactive system, type of acid on the yield and conductivity of polyaniline are discussed. The resulting polyaniline was characterized by IR and UV-Vis spectrometry. Polyaniline with a conductivity of 12.5 S/cm was obtained using 0.033 mol of aniline oxidized by 0.023 mol MnO2 in the presence of 100 mL of 2.7 mol/L HCl at 25degreesC for 4 h.

关键词： conducting polymers heteroatom-containing polymers manganese oxide oxidation polymerization polyaniline