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Olga Sambalova Emanuel Billeter Oguz Yildirim Andrea Sterzi Davide Bleiner Andreas Borgschulte 《International Journal of Hydrogen Energy》2021,46(5):3346-3353
External magnetic fields affect various electrochemical processes and can be used to enhance the efficiency of the electrochemical water splitting reaction. However, the driving forces behind this effect are poorly understood due to the analytical challenges of the available interface-sensitive techniques. Here, we present a set-up based on magneto- and electro-optical probing, which allows to juxtapose the magnetic properties of the electrode with the electrochemical current densities in situ at various applied potentials and magnetic fields. On the example of an archetypal hydrogen evolution catalyst, Pt (in a form of Co/Pt superlattice), we provide evidence that a magnetic field acts on the electrochemical double layer affecting the local concentration gradient of hydroxide ions, which simultaneously affects the magneto-optical and magnetocurrent response. 相似文献
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Real-Time Systems - Genetic algorithms can be used to generate input data in a real-time system that produce the worst-case execution time of a task. While generating the test data, the fitness... 相似文献
105.
This article considers the dispersion of hybrid and mono nanoparticles in a fluid with viscosity (Williamson) dependent on shear rate, over a heated surface moving with nonuniform velocity and exposed to a magnetic field in the presence of an applied current. Extensive modeling leads to complex coupled mathematical models that are solved numerically via the finite element method (FEM). Convergent simulations are run to investigate the role of parameters on the dynamics of flow fields. The magnetic field intensity plays a role in controlling the magnetohydrodynamic boundary layer thickness (BLT) and thermal radiation controls the thickness of thermal boundary layers (TBL). However, the magnetic field intensity is responsible for an increase in BLT. In contrast to this, thermal radiation plays a role in controlling the thickness of the TBL. The impact of shear rate dependent viscosity on velocity is remarkable for both fluids. The motion of both of the fluids slows down when viscosity varies as a function of shear rate. Viscosity depending on the shear rate has a significant impact on wall shear stress. It is observed from simulations that wall shear increases when the parameters appearing in the model for shear rate dependent viscosity are increased. However, this increase in wall shear stress associated with a hybrid nanofluid is greater than the increase in wall shear stress associated with a mono nanofluid. 相似文献
106.
Sara Paydar Jin Peng Liwen Huang Quan Shi Nabeela Akbar Quazi Arif Islam Akbar Muhammad Yueming Xing Jung-Sik Kim Yan Wu 《International Journal of Hydrogen Energy》2021,46(52):26478-26488
Exploring high conductive materials is still a challenge for high performance intermediate-temperature fuel cells. In this study, two-dimensional LiAl0.5Co0.5O2 (LACO) nanosheets coated by a compatible amorphous LiAlO2 (LAO) layer are evaluated as proton/Li+ conductor electrolyte. The fuel cell in which the LAO-LACO is used as electrolyte could deliver the maximum power output of 1120 mW cm?2 at 550 °C. The LAO coating enhances not only the ionic conductivity by modifying the space-charge regions, but also improves the LACO's chemical stability and device performance. Kelvin probe force microscopy further detected a local electric field (LEF) built in the LAO-LACO coating confines protons at the interface to transport fast. Such heterostructure with the LEF accelerating mechanism presents a novel approach for developing high-performance intermediate-temperature fuel cells. 相似文献
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Anwar Ghani Khwaja Mansoor Shahid Mehmood Shehzad Ashraf Chaudhry Arif Ur Rahman Malik Najmus Saqib 《International Journal of Communication Systems》2019,32(16)
Wireless sensor networks (WSN) consist of hundreds of miniature sensor nodes to sense various events in the surrounding environment and report back to the base station. Sensor networks are at the base of internet of things (IoT) and smart computing applications where a function is performed as a result of sensed event or information. However, in resource‐limited WSN authenticating a remote user is a vital security concern. Recently, researchers put forth various authentication protocols to address different security issues. Gope et al presented a protocol claiming resistance against known attacks. A thorough analysis of their protocol shows that it is vulnerable to user traceability, stolen verifier, and denial of service (DoS) attacks. In this article, an enhanced symmetric key‐based authentication protocol for IoT‐based WSN has been presented. The proposed protocol has the ability to counter user traceability, stolen verifier, and DoS attacks. Furthermore, the proposed protocol has been simulated and verified using Proverif and BAN logic. The proposed protocol has the same communication cost as the baseline protocol; however, in computation cost, it has 52.63% efficiency as compared with the baseline protocol. 相似文献
108.
Arif M. Abdullah Xiuling Li Paul V. Braun John A. Rogers K. Jimmy Hsia 《Advanced functional materials》2020,30(14)
Self‐assembly of 3D structures presents an attractive and scalable route to realize reconfigurable and functionally capable mesoscale devices without human intervention. A common approach for achieving this is to utilize stimuli‐responsive folding of hinged structures, which requires the integration of different materials and/or geometric arrangements along the hinges. It is demonstrated that the inclusion of Kirigami cuts in planar, hingeless bilayer thin sheets can be used to produce complex 3D shapes in an on‐demand manner. Nonlinear finite element models are developed to elucidate the mechanics of shape morphing in bilayer thin sheets and verify the predictions through swelling experiments of planar, millimeter‐scaled PDMS (polydimethylsiloxane) bilayers in organic solvents. Building upon the mechanistic understandings, The transformation of Kirigami‐cut simple bilayers into 3D shapes such as letters from the Roman alphabet (to make “ADVANCED FUNCTIONAL MATERIALS”) and open/closed polyhedral architectures is experimentally demonstrated. A possible application of the bilayers as tether‐less optical metamaterials with dynamically tunable light transmission and reflection behaviors is also shown. As the proposed mechanistic design principles could be applied to a variety of materials, this research broadly contributes toward the development of smart, tetherless, and reconfigurable multifunctional systems. 相似文献
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Solar Cells: Overcoming the Ambient Manufacturability‐Scalability‐Performance Bottleneck in Colloidal Quantum Dot Photovoltaics (Adv. Mater. 35/2018)
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