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- ItemCombining Battery‐Type and Pseudocapacitive Charge Storage in Ag/Ti3C2Tx MXene Electrode for Capturing Chloride Ions with High Capacitance and Fast Ion Transport(Hoboken, NJ : Wiley, 2020) Liang, Mingxing; Wang, Lei; Presser, Volker; Dai, Xiaohu; Yu, Fei; Ma, JieThe recent advances in chloride‐ion capturing electrodes for capacitive deionization (CDI) are limited by the capacity, rate, and stability of desalination. This work introduces Ti3C2Tx/Ag synthesized via a facile oxidation‐reduction method and then uses it as an anode for chloride‐ion capture in CDI. Silver nanoparticles are formed successfully and uniformly distributed with the layered‐structure of Ti3C2Tx. All Ti3C2Tx/Ag samples are hydrophilic, which is beneficial for water desalination. Ti3C2Tx/Ag samples with a low charge transfer resistance exhibit both pseudocapacitive and battery behaviors. Herein, the Ti3C2Tx/Ag electrode with a reaction time of 3 h exhibits excellent desalination performance with a capacity of 135 mg Cl− g−1 at 20 mA g−1 in a 10 × 10−3 m NaCl solution. Furthermore, low energy consumption of 0.42 kWh kg−1 Cl− and a desalination rate of 1.5 mg Cl− g−1 min−1 at 50 mA g−1 is achieved. The Ti3C2Tx/Ag system exhibits fast rate capability, high desalination capacity, low energy consumption, and excellent cyclability, which can be ascribed to the synergistic effect between the battery and pseudocapacitive behaviors of the Ti3C2Tx/Ag hybrid material. This work provides fundamental insight into the coupling of battery and pseudocapacitive behaviors during Cl− capture for electrochemical desalination.
- ItemSelective Out‐of‐Plane Optical Coupling between Vertical and Planar Microrings in a 3D Configuration(Hoboken, NJ : Wiley, 2020) Valligatla, Sreeramulu; Wang, Jiawei; Madani, Abbas; Naz, Ehsan Saei Ghareh; Hao, Qi; Saggau, Christian Niclaas; Yin, Yin; Ma, Libo; Schmidt, Oliver G.3D photonic integrated circuits are expected to play a key role in future optoelectronics with efficient signal transfer between photonic layers. Here, the optical coupling of tubular microcavities, supporting resonances in a vertical plane, with planar microrings, accommodating in‐plane resonances, is explored. In such a 3D coupled composite system with largely mismatched cavity sizes, periodic mode splitting and resonant mode shifts are observed due to mode‐selective interactions. The axial direction of the microtube cavity provides additional design freedom for selective mode coupling, which is achieved by carefully adjusting the axial displacement between the microtube and the microring. The spectral anticrossing behavior is caused by strong coupling in this composite optical system and is excellently reproduced by numerical modeling. Interfacing tubular microcavities with planar microrings is a promising approach toward interlayer light transfer with added optical functionality in 3D photonic systems.
- ItemTesting bias adjustment methods for regional climate change applications under observational uncertainty and resolution mismatch(Hoboken, NJ : Wiley, 2020) Casanueva, Ana; Herrera, Sixto; Iturbide, Maialen; Lange, Stefan; Jury, Martin; Dosio, Alessandro; Maraun, Douglas; Gutiérrez, José M.Systematic biases in climate models hamper their direct use in impact studies and, as a consequence, many statistical bias adjustment methods have been developed to calibrate model outputs against observations. The application of these methods in a climate change context is problematic since there is no clear understanding on how these methods may affect key magnitudes, for example, the climate change signal or trend, under different sources of uncertainty. Two relevant sources of uncertainty, often overlooked, are the sensitivity to the observational reference used to calibrate the method and the effect of the resolution mismatch between model and observations (downscaling effect). In the present work, we assess the impact of these factors on the climate change signal of temperature and precipitation considering marginal, temporal and extreme aspects. We use eight standard and state-of-the-art bias adjustment methods (spanning a variety of methods regarding their nature—empirical or parametric—, fitted parameters and trend-preservation) for a case study in the Iberian Peninsula. The quantile trend-preserving methods (namely quantile delta mapping (QDM), scaled distribution mapping (SDM) and the method from the third phase of ISIMIP-ISIMIP3) preserve better the raw signals for the different indices and variables considered (not all preserved by construction). However, they rely largely on the reference dataset used for calibration, thus presenting a larger sensitivity to the observations, especially for precipitation intensity, spells and extreme indices. Thus, high-quality observational datasets are essential for comprehensive analyses in larger (continental) domains. Similar conclusions hold for experiments carried out at high (approximately 20 km) and low (approximately 120 km) spatial resolutions. © 2020 The Authors. Atmospheric Science Letters published by John Wiley & Sons Ltd on behalf of the Royal Meteorological Society.
- ItemContact Aging Enhances Adhesion of Micropatterned Silicone Adhesives to Glass Substrates(Hoboken, NJ : Wiley, 2020) Thiemecke, Jonathan; Hensel, RenéThe transfer of biological concepts into synthetic micropatterned adhesives has recently enabled a new generation of switchable, reversible handling devices. Over the last two decades, many design principles have been explored that helped to understand the underlying mechanics and to optimize such adhesives for certain applications. An aspect that has been overlooked so far is the influence of longer hold times on the adhesive contacts. Exemplarily, the pull‐off stress and work of separation of a micropatterned adhesive specimen are enhanced by factors 3 and 6, respectively, after 1000 min in contact with a glass substrate. In addition to such global measures, the increase of adhesion of all individual micropillars is analyzed. It is found that contact aging varied across the microarray, as it drastically depends on local conditions. Despite great differences on the micropillar scale, the adhesion of entire specimens increased with very similar power laws, as this is determined by the mean contact ageing of the individual structures. Overall, contact aging must be critically evaluated before using micropatterned adhesives, especially for long‐term fixations and material combinations that are chemically attractive to each other.
- ItemVoltage‐Controlled Deblocking of Magnetization Reversal in Thin Films by Tunable Domain Wall Interactions and Pinning Sites(Hoboken, NJ : Wiley, 2020) Zehner, Jonas; Soldatov, Ivan; Schneider, Sebastian; Heller, René; Khojasteh, Nasrin B.; Schiemenez, Sandra; Fähler, Sebastian; Nielsch, Kornelius; Schäfer, Rudolf; Leistner, KarinHigh energy efficiency of magnetic devices is crucial for applications such as data storage, computation, and actuation. Redox‐based (magneto‐ionic) voltage control of magnetism is a promising room‐temperature pathway to improve energy efficiency. However, for ferromagnetic metals, the magneto‐ionic effects studied so far require ultrathin films with tunable perpendicular magnetic anisotropy or nanoporous structures for appreciable effects. This paper reports a fully reversible, low voltage‐induced collapse of coercivity and remanence by redox reactions in iron oxide/iron films with uniaxial in‐plane anisotropy. In the initial iron oxide/iron films, Néel wall interactions stabilize a blocked state with high coercivity. During the voltage‐triggered reduction of the iron oxide layer, in situ Kerr microscopy reveals inverse changes of coercivity and anisotropy, and a coarsening of the magnetic microstructure. These results confirm a magneto‐ionic deblocking mechanism, which relies on changes of the Néel wall interactions, and of the microstructural domain‐wall‐pinning sites. With this approach, voltage‐controlled 180° magnetization switching with high energy‐efficiency is achieved. It opens up possibilities for developing magnetic devices programmable by ultralow power and for the reversible tuning of defect‐controlled materials in general.
- ItemLabel‐Free Imaging of Cholesterol Assemblies Reveals Hidden Nanomechanics of Breast Cancer Cells(Hoboken, NJ : Wiley, 2020) Dumitru, Andra C.; Mohammed, Danahe; Maja, Mauriane; Yang, Jinsung; Verstraeten, Sandrine; del Campo, Aranzazu; Mingeot-Leclercq, Marie-Paule; Tyteca, Donatienne; Alsteens, DavidTumor cells present profound alterations in their composition, structural organization, and functional properties. A landmark of cancer cells is an overall altered mechanical phenotype, which so far are linked to changes in their cytoskeletal regulation and organization. Evidence exists that the plasma membrane (PM) of cancer cells also shows drastic changes in its composition and organization. However, biomechanical characterization of PM remains limited mainly due to the difficulties encountered to investigate it in a quantitative and label‐free manner. Here, the biomechanical properties of PM of a series of MCF10 cell lines, used as a model of breast cancer progression, are investigated. Notably, a strong correlation between the cell PM elasticity and oncogenesis is observed. The altered membrane composition under cancer progression, as emphasized by the PM‐associated cholesterol levels, leads to a stiffening of the PM that is uncoupled from the elastic cytoskeletal properties. Conversely, cholesterol depletion of metastatic cells leads to a softening of their PM, restoring biomechanical properties similar to benign cells. As novel therapies based on targeting membrane lipids in cancer cells represent a promising approach in the field of anticancer drug development, this method contributes to deciphering the functional link between PM lipid content and disease.
- ItemCarbon materials for stable Li metal anodes: Challenges, solutions, and outlook(Hoboken, NJ : Wiley, 2021) Lu, Q.; Jie, Y.; Meng, X.; Omar, A.; Mikhailova, D.; Cao, R.; Jiao, S.; Lu, Y.; Xu, Y.Lithium (Li) metal is regarded as the ultimate anode for next-generation Li-ion batteries due to its highest specific capacity and lowest electrochemical potential. However, the Li metal anode has limitations, including virtually infinite volume change, nonuniform Li deposition, and an unstable electrode–electrolyte interface, which lead to rapid capacity degradation and poor cycling stability, significantly hindering its practical application. To address these issues, intensive efforts have been devoted toward accommodating and guiding Li deposition as well as stabilizing the interface using various carbon materials, which have demonstrated excellent effectiveness, benefiting from their vast variety and excellent tunability of the structure–property relationship. This review is intended as a guide through the fundamental challenges of Li metal anodes to the corresponding solutions utilizing carbon materials. The specific functionalities and mechanisms of carbon materials for stabilizing Li metal anodes in these solutions are discussed in detail. Apart from the stabilization of the Li metal anode in liquid electrolytes, attention has also been paid to the review of anode-free Li metal batteries and solid-state batteries enabled by strategies based on carbon materials. Furthermore, we have reviewed the unresolved challenges and presented our outlook on the implementation of carbon materials for stabilizing Li metal anodes in practical applications.
- ItemArchitecture engineering of carbonaceous anodes for high‐rate potassium‐ion batteries(Hoboken, NJ : Wiley, 2021) Wu, Tianlai; Zhang, Weicai; Yang, Jiaying; Lu, Qiongqiong; Peng, Jing; Zheng, Mingtao; Xu, Fei; Liu, Yingliang; Liang, YeruThe limited lithium resource in earth's crust has stimulated the pursuit of alternative energy storage technologies to lithium‐ion battery. Potassium‐ion batteries (KIBs) are regarded as a kind of promising candidate for large‐scale energy storage owing to the high abundance and low cost of potassium resources. Nevertheless, further development and wide application of KIBs are still challenged by several obstacles, one of which is their fast capacity deterioration at high rates. A considerable amount of effort has recently been devoted to address this problem by developing advanced carbonaceous anode materials with diverse structures and morphologies. This review presents and highlights how the architecture engineering of carbonaceous anode materials gives rise to high‐rate performances for KIBs, and also the beneficial conceptions are consciously extracted from the recent progress. Particularly, basic insights into the recent engineering strategies, structural innovation, and the related advances of carbonaceous anodes for high‐rate KIBs are under specific concerns. Based on the achievements attained so far, a perspective on the foregoing, and proposed possible directions, and avenues for designing high‐rate anodes, are presented finally.
- ItemFlexible MXene films for batteries and beyond(Hoboken, NJ : Wiley, 2022) Huang, Yang; Lu, Qiongqiong; Wu, Dianlun; Jiang, Yue; Liu, Zhenjie; Chen, Bin; Zhu, Minshen; Schmidt, Oliver G.MXenes add dozens of metallic conductors to the family of two-dimensional (2D) materials. A top-down synthesis approach removing A-layer atoms (e.g., Al, Si, and Ga) in MAX phases to produce 2D flakes attaches various surface terminations to MXenes. With these terminations, MXenes show tunable properties, promising a range of applications from energy storage devices to electronics, including sensors, transistors, and antennas. MXenes are also excellent building blocks to create flexible films used for flexible and wearable devices. This article summarizes the synthesis of MXene flakes and highlights aspects that need attention for flexible devices. Rather than listing the development of energy storage devices in detail, we focus on the main challenges of and solutions for constructing high-performance devices. Moreover, we show the applications of MXene films in electronics to call on designs to construct a complete system based on MXene with good flexibility, which consists of a power source, sensors, transistors, and wireless communications.
- ItemZonalWave Number Diagnosis of RossbyWave-Like Oscillations Using Paired Ground-Based Radars(Hoboken, NJ : Wiley, 2020) He, Maosheng; Yamazaki, Yosuke; Hoffmann, Peter; Hall, Chris M.; Tsutsumi, Masaki; Li, Guozhu; Chau, Jorge LuisFree traveling Rossby wave normal modes (RNMs) are often investigated through large-scale space-time spectral analyses, which therefore is subject to observational availability, especially in the mesosphere. Ground-based mesospheric observations were broadly used to identify RNMs mostly according to the periods of RNMs without resolving their horizontal scales. The current study diagnoses zonal wave numbers of RNM-like oscillations occurring in mesospheric winds observed by two meteor radars at about 79°N. We explore four winters comprising the major stratospheric sudden warming events (SSWs) 2009, 2010, and 2013. Diagnosed are predominant oscillations at the periods of 10 and 16 days lasting mostly for three to five whole cycles. All dominant oscillations are associated with westward zonal wave number m=1, excepting one 16-day oscillation associated with m=2. We discuss the m=1 oscillations as transient RNMs and the m=2 oscillation as a secondary wave of nonlinear interaction between an RNM and a stationary Rossby wave. All the oscillations occur around onsets of the three SSWs, suggesting associations between RNMs and SSWs. For comparison, we also explore the wind collected by a similar network at 54°N during 2012–2016. Explored is a manifestation of 5-day wave, namely, an oscillation at 5–7 days with m=1), around the onset of SSW 2013, supporting the associations between RNMs and SSWs. ©2020. The Authors.