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121.
Gang Wang Benjamin Kohn Ulrich Scheler Faxing Wang Steffen Oswald Markus Löffler Deming Tan Panpan Zhang Jian Zhang Xinliang Feng 《Advanced materials (Deerfield Beach, Fla.)》2020,32(4):1905681
The intrinsic advantages of metallic Zn, like high theoretical capacity (820 mAh g−1), high abundance, low toxicity, and high safety have driven the recent booming development of rechargeable Zn batteries. However, the lack of high-voltage electrolyte and cathode materials restricts the cell voltage mostly to below 2 V. Moreover, dendrite formation and the poor rechargeability of the Zn anode hinder the long-term operation of Zn batteries. Here a high-voltage and durable Zn–graphite battery, which is enabled by a LiPF6-containing hybrid electrolyte, is reported. The presence of LiPF6 efficiently suppresses the anodic oxidation of Zn electrolyte and leads to a super-wide electrochemical stability window of 4 V (vs Zn/Zn2+). Both dendrite-free Zn plating/stripping and reversible dual-anion intercalation into the graphite cathode are realized in the hybrid electrolyte. The resultant Zn–graphite battery performs stably at a high voltage of 2.8 V with a record midpoint discharge voltage of 2.2 V. After 2000 cycles at a high charge–discharge rate, high capacity retention of 97.5% is achieved with ≈100% Coulombic efficiency. 相似文献
122.
Ke He Yaqing Liu Ming Wang Geng Chen Ying Jiang Jiancan Yu Changjin Wan Dianpeng Qi Meng Xiao Wan Ru Leow Hui Yang Markus Antonietti Xiaodong Chen 《Advanced materials (Deerfield Beach, Fla.)》2020,32(4):1905399
The emulation of human sensation, perception, and action processes has become a major challenge for bioinspired intelligent robotics, interactive human–machine interfacing, and advanced prosthetics. Reflex actions, enabled through reflex arcs, are important for human and higher animals to respond to stimuli from environment without the brain processing and survive the risks of nature. An artificial reflex arc system that emulates the functions of the reflex arc simplifies the complex circuit design needed for “central-control-only” processes and becomes a basic electronic component in an intelligent soft robotics system. An artificial somatic reflex arc that enables the actuation of electrochemical actuators in response to the stimulation of tactile pressures is reported. Only if the detected pressure by the pressure sensor is above the stimulus threshold, the metal–organic-framework-based threshold controlling unit (TCU) can be activated and triggers the electrochemical actuators to complete the motion. Such responding mechanism mimics the all-or-none law in the human nervous system. As a proof of concept, the artificial somatic reflex arc is successfully integrated into a robot to mimic the infant grasp reflex. This work provides a unique and simplifying strategy for developing intelligent soft robotics, next-generation human–machine interfaces, and neuroprosthetics. 相似文献
123.
Mohammad Mahdi Tavakoli Giovanni Azzellino Marek Hempel Ang‐Yu Lu Francisco J. Martin‐Martinez Jiayuan Zhao Jingjie Yeo Tomas Palacios Markus J. Buehler Jing Kong 《Advanced functional materials》2020,30(31)
A roll‐to‐roll (R2R) transfer technique is employed to improve the electrical properties of transferred graphene on flexible substrates using parylene as an interfacial layer. A layer of parylene is deposited on graphene/copper (Cu) foils grown by chemical vapor deposition and are laminated onto ethylene vinyl acetate (EVA)/poly(ethylene terephthalate). Then, the samples are delaminated from the Cu using an electrochemical transfer process, resulting in flexible and conductive substrates with sheet resistances of below 300 Ω sq?1, which is significantly better (fourfold) than the sample transferred by R2R without parylene (1200 Ω sq?1). The characterization results indicate that parylene C and D dope graphene due to the presence of chlorine atoms in their structure, resulting in higher carrier density and thus lower sheet resistance. Density functional theory calculations reveal that the binding energy between parylene and graphene is stronger than that of EVA and graphene, which may lead to less tear in graphene during the R2R transfer. Finally, organic solar cells are fabricated on the ultrathin and flexible parylene/graphene substrates and an ultra‐lightweight device is achieved with a power conversion efficiency of 5.86%. Additionally, the device shows a high power per weight of 6.46 W g?1 with superior air stability. 相似文献
124.
Monitoring the structural health and integrity of coated components is of vital importance to increase their lifetime and the overall sustainability of the targeted applications. Here, the temporal oxidation behavior of TiN thin films is tracked using in situ sheet resistance measurements. Based on correlative film morphology, structure, and local composition data, it is evident that observed resistance changes are caused by oxidation of TiN. Thickness measurements of the remaining TiN under the oxide layer are in very good agreement with thicknesses deduced from in situ sheet resistance measurements. Hence, the in situ measured sheet resistance is an autonomous self‐reporting property useful for tracking the temporal oxidation behavior of TiN coatings. 相似文献
125.
Marius Keunecke Fryderyk Lyzwa Danny Schwarzbach Vladimir Roddatis Nicolas Gauquelin Knut Müller‐Caspary Johann Verbeeck Sara J. Callori Frank Klose Markus Jungbauer Vasily Moshnyaga 《Advanced functional materials》2020,30(18)
Heterostructures of strongly correlated oxides demonstrate various intriguing and potentially useful interfacial phenomena. LaMnO3/SrMnO3 superlattices are presented showcasing a new high‐temperature ferromagnetic phase with Curie temperature, TC ≈360 K, caused by electron transfer from the surface of the LaMnO3 donor layer into the neighboring SrMnO3 acceptor layer. As a result, the SrMnO3 (top)/LaMnO3 (bottom) interface shows an enhancement of the magnetization as depth‐profiled by polarized neutron reflectometry. The length scale of charge transfer, λTF ≈2 unit cells, is obtained from in situ growth monitoring by optical ellipsometry, supported by optical simulations, and further confirmed by high resolution electron microscopy and spectroscopy. A model of the inhomogeneous distribution of electron density in LaMnO3/SrMnO3 layers along the growth direction is concluded to account for a complex interplay between ferromagnetic and antiferromagnetic layers in superlattices. 相似文献
126.
Innovative and modern planning methods in bridge construction Building Information Modeling (BIM) offers the opportunity to realize modern large-scale projects on schedule and within budget during the planning, construction and operation of a building. Because consistent data throughout the entire process can increase the efficiency and quality of a building. Bridge construction in particular poses a special challenge here, since despite recurring typology, the dependencies of the individual components for routing make each structure individual. This problem can be solved by parameterizing the building models. In concrete terms, this means that each structural element is given at least one dependency for the routing of the road/railway above or below the bridge on the basis of the space curve. If the route changes, the structure will also adapt. This permanent connection also allows quantities, component lists and 2-D plans to be adapted automatically. Dependencies of the components on each other or on the terrain model are also possible. This means that collisions within the building can be avoided during the planning phase. Intelligent data models can help to increase the quality, efficiency and productivity in the realisation of project-specific buildings. 相似文献
127.
Univ.-Prof. Dr.-Ing. Markus Feldmann Sandro Citarelli Univ.-Prof. Dr.-Ing. Sebastian Münstermann Markus Könemann 《Stahlbau》2020,89(12):1016-1026
Equivalent upper shelf toughness requirements for weld bead bend test (AUBI) substitution For about more than ten years, in Germany, the weld bead bending test, the so called “Aufschweißbiegeversuch“ (AUBI), has been abolished for a series of cases, especially for fine grain structural steels. However, the corresponding investigations had revealed only an empirical correlation with charpy energy on upper shelf. The material and mechanical interactions so far, had not been clarified. So it was the task to bring light into the complexity of upper shelf toughness and AUBI using hybrid damage models and taking into account of both brittle cleavage and tough ductile failure. This allows the simulation of lower and upper shelf behaviour including the transition range. As a result, now the AUBI can be analyzed far better as we are able to establish a material-mechanically justified correlation with the charpy energy. Interestingly, it revealed that the resulting upper shelf toughness requirements for constant bending angles are different for different steel grades. Such requirements for upper shelf toughness are necessary for the development of the ultimate loads in the ULS, especially for bridges or other structures, where cracks are to be expected. 相似文献
128.
Univ.-Prof. Dr.-Ing. Markus Kuhnhenne Marius Vontein Dipl.-Ing. Gesa Pauli Dr.-Ing. Simon Schaffrath 《Stahlbau》2020,89(11):912-922
Thermally improved steel substructures for metal facades Substructures of facades penetrate the thermal insulation and thus form a thermal bridge, which can be compensated by higher insulation thicknesses or by material selection. This redesign is often done at a late stage and is associated with considerable additional costs. If the construction tolerances allow, the change from a classic two-part substructure consisting of a bracket and mounting rail to a one-part substructure as a Z-profile can be useful and lead to a quicker, and thus more cost-effective, installation. As linear components, one-piece substructures initially exhibit a greater thermal bridge effect than the two-part design with brackets and mounting rail, but can be upgraded by the insertion of slots in such a way that the building law requirements for thermal protection can be achieved without increasing the insulation thickness. The Z-profiles are attached straight to the load-bearing anchoring base and directly form the support profile for the facade elements. Static investigations of the Z-profiles weakened by the slots show that a sufficient load-bearing capacity can be achieved. 相似文献
129.
Prof. Dr.-Ing. Antje Simon Dr.-Ing. Markus G. Jahreis Johannes Koch Prof. Dr.-Ing. Ralf W. Arndt 《Bautechnik》2020,97(2):85-91
Design, construction and maintenance of modern timber bridges – part 1: design Efficiency in planning and construction of durable structures is achieved by using regulations based on the current state of the art. In bridge construction, a comprehensive set of rules exists for bridges made of reinforced and prestressed concrete or of steel and steel-concrete-composites. For timber bridges, such rules are lacking. There are no regulations for the design, construction, maintenance and inspection of timber bridges. The research project “Protected Timber Bridges (ProTimB)” has been initiated at the University of Applied Sciences Erfurt to reduce the considerable competitive disadvantages for timber bridges. The project aimed at the development of a unified set of rules for the design, the construction and the maintenance of protected timber bridges according to the existing regulations for other materials. Two articles are presenting the most important results of this project. The present article gives an overview over the content of the whole project und shows the new set of design rules for protected timber bridges. It focuses on the new sample drawings and the structural protection rules. The new design guidelines support the planning engineers to develop durable and sustainable timber bridges. They contribute to the renaissance of bridge construction using the great material timber. 相似文献
130.
引言欧洲电力市场的自由化对电网运行公司产生一个费用增加的压力。因此 ,很多公司越来越致力于以优选或简单地减少维修工作来减少电网运行费用。随着维修从预防策略转变到事件驱动或以状态为基础的策略 ,可以节省以前的大量维修工作 (比较 [1、2 ])。但在另一方面 ,随着维修工作的大量减少而来的是较少可靠的电网组件 ,以致较低的用户供电质量。因此不可能再次均匀地减少整个电网的维修工作 ,特别是由于维修工作和组件可靠性与用户供电质量之间不清楚的相互关系。本文介绍一种优选 110kV配电网中维修工作的方法 ,因此通过考虑整个电网的一… 相似文献