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941.
Hannah C. Nerl Anuj Pokle Lewys Jones Knut Müller‐Caspary Karel H. W. van den Bos Clive Downing Eoin K. McCarthy Nicolas Gauquelin Quentin M. Ramasse Ivan Lobato Dermot Daly Juan Carlos Idrobo Sandra Van Aert Gustaaf Van Tendeloo Stefano Sanvito Jonathan N. Coleman Clotilde S. Cucinotta Valeria Nicolosi 《Advanced functional materials》2019,29(37)
The fabrication of 2D systems for electronic devices is not straightforward, with top‐down low‐yield methods often employed leading to irregular nanostructures and lower quality devices. Here, a simple and reproducible method to trigger self‐assembly of arrays of high aspect‐ratio chiral copper heterostructures templated by the structural anisotropy in black phosphorus (BP) nanosheets is presented. Using quantitative atomic resolution aberration‐corrected scanning transmission electron microscopy imaging, in situ heating transmission electron microscopy and electron energy‐loss spectroscopy arrays of heterostructures forming at speeds exceeding 100 nm s?1 and displaying long‐range order over micrometers are observed. The controlled instigation of the self‐assembly of the Cu heterostructures embedded in BP is achieved using conventional electron beam lithography combined with site specific placement of Cu nanoparticles. Density functional theory calculations are used to investigate the atomic structure and suggest a metallic nature of the Cu heterostructures grown in BP. The findings of this new hybrid material with unique dimensionality, chirality, and metallic nature and its triggered self‐assembly open new and exciting opportunities for next generation, self‐assembling devices. 相似文献
942.
Zhang Xin Kadimisetty Karteek Yin Kun Ruiz Carlos Mauk Michael G. Liu Changchun 《Microsystem Technologies》2019,25(8):3105-3110
Microsystem Technologies - Hand hygiene compliance is one of the most effective means to prevent the spread of infections and diseases. The centers for disease control and prevention (CDC)... 相似文献
943.
944.
945.
Diego Erena Jesús Vzquez Valeo Carlos Navarro Jaime Domínguez 《Fatigue & Fracture of Engineering Materials & Structures》2020,43(1):149-161
Fatigue failure of cables and strands is a common and complex problem. Failure is typically caused by different combinations of time‐variable bending and axial forces. In addition to these loads, contact stresses between wires may play an important role in the fatigue failure of cables. The present work aims to provide deep insight into the fatigue failure of a seven‐wire stainless steel strand subjected to a combination of variable axial and bending loads. To avoid side effects in the analysis, fatigue failure of the strand close to the clamps is prevented. Several tests were performed with a new device specifically designed to avoid failure near the clamps. Thus, failure is always produced at the middle length of the specimen. Test simulations were performed by employing the finite element method. The numerical results were validated via comparisons with experimental data. Finally, life prediction curves were obtained. 相似文献
946.
Susana Díaz‐Amaya Min Zhao Li‐Kai Lin Carlos Ostos Jan P. Allebach George T.‐C. Chiu Amanda J. Deering Lia A. Stanciu 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(24)
The increasing incidence of infectious outbreaks from contaminated food and water supply continues imposing a global burden for food safety, creating a market demand for on‐site, disposable, easy‐to‐use, and cost‐efficient devices. Despite of the rapid growth of biosensors field and the generation of breakthrough technologies, more than 80% of the platforms developed at lab‐scale never will get to meet the market. This work aims to provide a cost‐efficient, reliable, and repeatable approach for the detection of foodborne pathogens in real samples. For the first time an optimized inkjet printing platform is proposed taking advantage of a carefully controlled nanopatterning of novel carboxyl‐functionalized aptameric ink on a nitrocellulose substrate for the highly efficient detection of E. coli O157:H7 (25 colony forming units (CFU) mL?1 in pure culture and 233 CFU mL?1 in ground beef) demonstrating the ability to control the variation within ±1 SD for at least 75% of the data collected even at very low concentrations. From the best of the knowledge this work reports the lowest limit of detection of the state of the art for paper‐based optical detection of E. coli O157:H7, with enough evidence (p > 0.05) to prove its high specificity at genus, species, strain, and serotype level. 相似文献
947.
Simone Aparecida da Silva Lincoln Brum de Leite Gusmão Pinheiro Yuri Aparecido Opata João Frederico Haas Leandro Monteiro Francisco Carlos Serbena Gelson Biscaia de Souza Ezequiel Costa Siqueira Alcione Roberto Jurelo 《Journal of Superconductivity and Novel Magnetism》2018,31(8):2363-2372
This paper reports a study on the mechanical and tribological properties of ab- and a (b) c?planes of YBa2Cu3O7?δ single crystals. The single crystals were grown using a CuO-BaO self-flux method. The oxygenation effect on the mechanical and tribological properties of ab- and a (b) c?planes is reported. For the ab- plane, the hardness and elastic modulus were around 6 and 50 GPa, respectively. In this case, significant differences were not observed among the hardness and elastic modulus at different oxygenation states. However, the hardness and elastic modulus for as-grown and oxygenated YBa2Cu3O7?δ single crystals were different from that of the a (b) c?plane, and were observed to be slightly higher for the as-grown than for the oxygenated samples. For as-grown and oxygenated samples, we observed hardness values around 4.7 and 2.0 GPa, respectively. Regarding the elastic modulus, the values were 75 and 40 GPa, respectively. The indentation fracture toughness values on the ab- plane for the as-grown and oxygenated YBa2Cu3O7?δ single crystal were 3.7 ± 1.2 and 2.9 ± 1.2 MPa m1/2, respectively. For the ab- plane, the scratch resistance of the as-grown sample was higher than that of the oxygenated sample and the scratches under load were deeper for the oxygenated sample. As regards the a (b) c?plane, the scar features were seemingly constant through all the scratch lengths and the scratches under load were deeper and larger for the oxygenated than that for the as-grown sample. 相似文献
948.
Ehsan Akbari Molly Y. Mollica Christopher R. Lucas Sarah M. Bushman Randy A. Patton Melika Shahhosseini Jonathan W. Song Carlos E. Castro 《Advanced materials (Deerfield Beach, Fla.)》2017,29(46)
A specific and reversible method is reported to engineer cell‐membrane function by embedding DNA‐origami nanodevices onto the cell surface. Robust membrane functionalization across epithelial, mesenchymal, and nonadherent immune cells is achieved with DNA nanoplatforms that enable functions including the construction of higher‐order DNA assemblies at the cell surface and programed cell–cell adhesion between homotypic and heterotypic cells via sequence‐specific DNA hybridization. It is anticipated that integration of DNA‐origami nanodevices can transform the cell membrane into an engineered material that can mimic, manipulate, and measure biophysical and biochemical function within the plasma membrane of living cells. 相似文献
949.
Carlos M. Poventud-Estrada Raúl Acevedo Camila Morales Luis Betancourt Diana C. Diaz Manuel A. RodriguezIII Eduardo Larios Miguel José-Yacaman Eduardo Nicolau Michael Flynn Carlos R. Cabrera 《Microgravity science and technology》2017,29(5):381-389
The effect of microgravity on the electrochemical oxidation of ammonia at platinum nanoparticles supported on modified mesoporous carbons (MPC) with three different pore diameters (64, 100, and 137 Å) was studied via the chronoamperometric technique in a half-cell. The catalysts were prepared by a H2 reductive process of PtCl\(_{6}^{\mathrm {4-}}\) in presence of the mesoporous carbon support materials. A microgravity environment was obtained with an average gravity of less than 0.02 g created aboard an airplane performing parabolic maneuvers. Results show the chronoamperommetry of the ammonia oxidation reaction in 1.0 M NH4OH at 0.60 V vs. RHE under microgravity conditions. The current density, in all three catalysts, decreased while in microgravity conditions when compared to ground based experiments. Under microgravity, all three catalysts yielded a decrease in ammonia oxidation reaction current density between 25 to 63% versus terrestrial experimental results, in time scales between 1 and 15 s. The Pt catalyst prepared with mesoporous carbon of 137 Å porous showed the smallest changes, between 25 to 48%. Nanostructuring catalyst materials have an effect on the level of current density decrease under microgravity conditions. 相似文献
950.
Juan Carlos Gonzalez-Rosillo Moran Balaish Zachary D. Hood Neel Nadkarni Dimitrios Fraggedakis Kun Joong Kim Kaitlyn M. Mullin Reto Pfenninger Martin Z. Bazant Jennifer L. M. Rupp 《Advanced materials (Deerfield Beach, Fla.)》2020,32(9):1907465
Specialized hardware for neural networks requires materials with tunable symmetry, retention, and speed at low power consumption. The study proposes lithium titanates, originally developed as Li-ion battery anode materials, as promising candidates for memristive-based neuromorphic computing hardware. By using ex- and in operando spectroscopy to monitor the lithium filling and emptying of structural positions during electrochemical measurements, the study also investigates the controlled formation of a metallic phase (Li7Ti5O12) percolating through an insulating medium (Li4Ti5O12) with no volume changes under voltage bias, thereby controlling the spatially averaged conductivity of the film device. A theoretical model to explain the observed hysteretic switching behavior based on electrochemical nonequilibrium thermodynamics is presented, in which the metal-insulator transition results from electrically driven phase separation of Li4Ti5O12 and Li7Ti5O12. Ability of highly lithiated phase of Li7Ti5O12 for Deep Neural Network applications is reported, given the large retentions and symmetry, and opportunity for the low lithiated phase of Li4Ti5O12 toward Spiking Neural Network applications, due to the shorter retention and large resistance changes. The findings pave the way for lithium oxides to enable thin-film memristive devices with adjustable symmetry and retention. 相似文献