bluuebunny/crossref_metadata_2025_split huggingface dataset:
Perfect Absorption in a Disordered Medium with Programmable Meta‐Atom Inclusions
Authors: F. Imani Mohammadreza , Smith David R. , del Hougne Philipp 
Published: September 2020

AbstractAchieving the very special condition of perfect absorption (PA) in a complex scattering enclosure promises to enable a wealth of applications in secure communication, precision sensing, wireless power transfer, analog signal processing, and random lasing. Consequently, a lot of recent research effort is dedicated to proposing wave‐front shaping protocols to implement coherent PA in complex scattering environments with tunable localized absorption as well as a tunable excitation frequency. Here, the conceptually different route of solely tweaking the randomness of the complex scattering environment in order to achieve PA is proposed. An experimental proof‐of‐concept in the microwave domain is provided where the randomness of a 3D chaotic cavity is tuned with programmable meta‐atom inclusions. The achievability and extreme sensitivity of the PA condition are systematically investigated. The presented technique can impose a PA condition at over hundred distinct frequencies within a small frequency band, enabling the proposal and experimental demonstration of a concrete practical application: receiver‐powered secure wireless communication in a complex scattering enclosure. The presented fundamentally new perspective on PA applies to all types of wave phenomena; the experimental results foreshadow the large potential of this novel tool for minute wave control in sensing, communication, and energy transfer.
Probing the Growth of Organic Molecular Films Embedded between Cobalt and Iron Electrodes: Ferromagnetic Nuclear Resonance Approach
Authors: Avedissian Garen , Arabski Jacek , Wytko Jennifer A. , Weiss Jean , Meny Christian 
Published: September 2020

AbstractPhysical properties of magnetic nanostructures and devices strongly depend on the morphological characteristics of their various components. This is especially true and becomes particularly complex in hybrid nanostructures, where soft organic molecules are at the vicinity of ferromagnetic metallic films. The supramolecular architecture of molecular films embedded between Fe and Co layers is investigated by ferromagnetic nuclear resonance (FNR). With such sample architecture, the presence of pin holes in the organic layers is detected by FNR contributions in a specific spectral range. The methodology that is developed allows the probing of the continuity and the packing of zinc tetraphenyl porphyrin (ZnTPP) molecular films between the Co and Fe films. The experimental results suggest that, regardless of the nature of the ferromagnetic underlayer, at least 15 monolayers of ZnTPP are necessary to form continuous and pin‐hole free molecular films. In addition, quantitative analyses show that ZnTPP layers exhibit distinct morphologies that are dependent on the nature of the ferromagnetic metallic underlayer.
Self‐Assembled Perovskite Nanowire Clusters for High Luminance Red Light‐Emitting Diodes
Authors: Bi Chenghao , Hu Jingcong , Yao Zhiwei , Lu Yue , Binks David , Sui Manling , Tian Jianjun 
Published: September 2020

AbstractBright red emission (620–650 nm) from perovskite light‐emitting diodes (PeLEDs) is usually achieved via a composition including both bromine and iodine anions, which results in poor performance and stability due to phase separation under operating conditions. Here a large‐scale ligand‐assisted reprecipitation method is devised with nonpolar solvent that enables the fabrication of CsPbI3 nanowire clusters, emitting at 600 nm. The blue‐shift of this emission relative to that of bulk CsPbI3 (≈700 nm) is attributed to quantum confinement in nanowires. The growth of the nanowires is along the [011] crystal direction and is vacancy driven, resulting in the healing of surface defects and thereby a high photoluminescence quantum yield of 91%. The clusters with ultralow trap density show remarkable structural and environmental stability. PeLEDs based on these clusters exhibit an external quantum efficiency of 6.2% with Commission Internationale de l'Eclairage coordinates of (0.66, 0.34), and record luminance of 13 644 cd m−2 of red electroluminescence. The half‐lifetime under an accelerated stability test is 13.5 min for an unencapsulated device in ambient conditions operating at an initial luminance of 11 500 cd m−2, which corresponds to an estimated half‐lifetime of 694 h at 100 cd m−2 based on acceleration factor obtained by experimental testing.
Electrical Dynamic Switching of Magnetic Plasmon Resonance Based on Selective Lithium Deposition
Authors: Jin Yan , Liang Jie , Wu Shan , Zhang Ye , Zhou Lin , Wang Qianjin , Liu Hui , Zhu Jia 
Published: September 2020

AbstractActive plasmonic nanostructures have garnered considerable interest in physics, chemistry, and material science due to the dynamically switchable capability of plasmonic responses. Here, the first electrically dynamic control of magnetic plasmon resonance (MPR) through structure transformation by selective deposition of lithium on a metal–insulator–metal (MIM) structure is reported. Distinct optical switching between MPR and surface plasmon polariton (SPP) excitations can be enabled by applying a proper electrical current to the electrochemical cell. Furthermore, the structure transformation through lithium metal deposition indicates the reconfigurable MPR excitation in a full cycling of the charging and discharging process. The results may shed light on electrically compatible self‐powered active plasmonics as well as nondestructive optical sensing for electrochemical evolution.
Nanometer‐Scale Uniform Conductance Switching in Molecular Memristors
Authors: Goswami Sreetosh , Deb Debalina , Tempez Agnès , Chaigneau Marc , Rath Santi Prasad , Lal Manohar , Ariando  , Williams R. Stanley , Goswami Sreebrata , Venkatesan Thirumalai 
Published: September 2020

AbstractOne common challenge highlighted in almost every review article on organic resistive memory is the lack of areal switching uniformity. This, in fact, is a puzzle because a molecular switching mechanism should ideally be isotropic and produce homogeneous current switching free from electroforming. Such a demonstration, however, remains elusive to date. The reports attempting to characterize a nanoscopic picture of switching in molecular films show random current spikes, just opposite to the expectation. Here, this longstanding conundrum is resolved by demonstrating 100% spatially homogeneous current switching (driven by molecular redox) in memristors based on Ru‐complexes of azo‐aromatic ligands. Through a concurrent nanoscopic spatial mapping using conductive atomic force microscopy and in operando tip‐enhanced Raman spectroscopy (both with resolution <7 nm), it is shown that molecular switching in the films is uniform from hundreds of micrometers down to the nanoscale and that conductance value exactly correlates with spectroscopically determined molecular redox states. This provides a deterministic molecular route to obtain spatially homogeneous, forming‐free switching that can conceivably overcome the chronic problems of robustness, consistency, reproducibility, and scalability in organic memristors.
Space‐Confined Fabrication of MoS2@Carbon Tubes with Semienclosed Architecture Achieving Superior Cycling Capability for Sodium Ion Storage
Authors: Zhang Yuan , Liu Wei , Wang Tianqi , Du Yongxu , Cui Yongpeng , Liu Shuang , Wang Huanlei , Liu Shuai , Chen Ming , Zhou Junan 
Published: September 2020

AbstractHigh rate and good cycling capability are always difficult for sodium ion anode materials owing to the unstable electrode structure induced by reversibly intercalation of large‐sized sodium ions. In this paper, based on the unique nanotube arrays of crab shells, a novel space‐confined growth of MoS2 nanosheets in carbon nanotubes is reported to fabricate MoS2@carbon nanotube (MoS2@CT) with a semienclosed architecture. Due to the space‐confined effect, MoS2 sheets are nanosized with poor stacking feature, which are anchored on the inner surface of carbon tubes. The semienclosed architecture built of carbon nanotubes and abundant MoS2 nanosheets enhances the stability and integrity of the electrode structure during cycles. Thereby, the coupling effect of stable structure and MoS2 with fast kinetics achieves a comprehensive performance improvement of the MoS2@CT anode materials. Particularly for cycling capability, it delivers a capacity of 170 mAh g−1 after 10 000 cycles at a high current density of 10 A g−1, which is comparable for most previously reported cases. The assembled Na‐ion hybrid supercapacitors device delivers a high energy density of 82 Wh kg−1 at a power density of 2000 W kg−1 after 5000 cycles with an 89% retention.
Gold Nanoparticles Functionalized with Fullerene Derivative as an Effective Interface Layer for Improving the Efficiency and Stability of Planar Perovskite Solar Cells
Authors: Chavan Rohit D. , Prochowicz Daniel , Bończak Bartłomiej , Tavakoli Mohammad Mahdi , Yadav Pankaj , Fiałkowski Marcin , Hong Chang Kook 
Published: September 2020

AbstractTitanium dioxide (TiO2) is an extensively used electron transporting layer (ETL) in n–i–p perovskite solar cells (PSCs). Although, TiO2 ETL experiences the high surface defect together with low electron extraction ability, which causes severe energy loss and poor stability in the PSC. In this study, a new intermediate layer consisting of gold nanoparticles functionalized with fully conjugated fullerene C60 derivative (C60‐BCT@Au NPs) that enhances the interfacial contact at ETL/perovskite interface leading to a perovskite film with improved crystallinity and morphology is reported. Moreover, the studies demonstrate that the interface modification of the TiO2 ETL with C60‐BCT@Au NPs substantially improves the charge extraction efficiency from the perovskite layer and suppresses charge recombination processes. Consequently, the resulting device yields a champion efficiency of 19.08% as well as devaluation in hysteresis. In addition, the unencapsulated PSCs with c‐TiO2/C60‐BCT@Au NPs ETL retain 83% and 90% of their original PCEs after 500 h storage in air and exposure to continuous UV illumination for 200 h, respectively. This study provides an effective method to address the electron transporting issues between perovskite and c‐TiO2 ETL for developing stable and efficient PSCs.
Biocompatible and Highly Stretchable PVA/AgNWs Hydrogel Strain Sensors for Human Motion Detection
Authors: Azadi Shohreh , Peng Shuhua , Moshizi Sajad A. , Asadnia Mohsen , Xu Jiangtao , Park Inkyu , Wang Chun H. , Wu Shuying 
Published: September 2020

AbstractHydrogel‐based strain sensors have attracted considerable interest for applications such as skin‐like electronics for human motion detection, soft robotics, and human–machine interfaces. However, fabrication of hydrogel strain sensors with desirable mechanical and piezoresistive properties is still challenging. Herein, a biocompatible hydrogel sensor is presented, which is made of polyvinyl alcohol (PVA) nanocomposite with high stretchability up to 500% strain, high mechanical strength of 900 kPa, and electrical conductivity (1.85 S m‐1) comparable to human skin. The hydrogel sensors demonstrate excellent linearity in the whole detection range and great durability under cyclic loading with low hysteresis of 7%. These excellent properties are believed to be contributed by a new bilayer structural design, i.e., a thin, conductive hybrid layer of PVA/silver nanowires (AgNWs) deposited on a pure strong PVA substrate. PVA solution of high concentration is used to fabricate the substrate while the top layer consists of dilute PVA solution so that high content of AgNWs can be dispersed to achieve high electrical conductivity. Together with a rapid response time (0.32 s) and biocompatibility, this new sensor offers great potential as a wearable sensor for epidermal sensing applications, e.g., detecting human joint and muscle movements.
Unraveling Reversible Quenching Processes of O2, N2, Ar, and H2O in Metal Halide Perovskites at Moderate Photon Flux Densities
Authors: Nandayapa Edgar R. , Hirselandt Katrin , Boeffel Christine , Unger Eva L. , List‐Kratochvil Emil J. W. 
Published: September 2020

AbstractMetal halide perovskites (MHP), as used in photovoltaic (PV) applications, show a rich photophysics in inert and ambient atmosphere. The presence of atmospheric molecules leads to processes that enhance as well as reduce their photoluminescence (PL) emission. Various phenomena are previously described for a wide variety of gas molecules and different classes of MHP, with a particular interest on the long‐term stability for PV applications. However, reversible PL quenching (PLQ) processes, which may be regarded equally important for the performance of PV and other optoelectronic applications, are neglected in other studies. This holds true for O2 and H2O, but especially for low‐reactive gases such as nitrogen and argon. Using low excitation densities, it is shown that noticeable—and reversible—PLQ, in addition to PL enhancements, can already be observed for O2, N2, and Ar as well as for H2O at low concentrations of 1 mbar. The nature and origin of the quenching processes are further elucidated by applying the Stern–Volmer analysis, also employed to determine whether static and dynamic PLQ processes happen for the different quenching gases. The strongest static PLQ is found for O2 and H2O. MHPs in N2 and Ar atmospheres display a moderate PLQ effect.
Nitrogen forms in runoff export from St. Augustinegrass
Authors: Fontanier Charles H. , Aitkenhead‐Peterson Jacqueline A. , Wherley Benjamin G. , Ojeda Nadezda , White Richard H. , Thomas James C. , Dwyer Phil 
Published: September 2020

AbstractNitrogen exports from landscapes can contribute to the eutrophication of surface waters. The most common form of N studied in prior runoff research has been nitrate, although ammoniacal and organic forms of N are also considered important causes of eutrophication. The relative abundance of each N form in runoff from turfgrasses has not been widely reported. The objective of this study was to quantify dissolved inorganic N (DIN) and dissolved organic N (DON) exports in runoff from St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] turf over a 2‐yr period in College Station, TX. Treatments were arranged as a randomized complete block design having eight combinations of irrigation (100, 75, or 50% of estimated turfgrass water requirements) and fertility level (0, 88, and 176 kg N ha−1 yr−1). Runoff from 31 rainfall events and one excess irrigation event were used to estimate annual and seasonal DIN and DON exports. Nitrate‐N concentration was typically below 5 mg L−1, but peaks in excess of 20 mg L−1 were measured during late winter in one year. Aside from this atypical peak, the largest portion of total dissolved N (TDN) was DON, whereas NH4–N was typically the smallest portion. Increasing fertilizer rates typically amplified each form of N in runoff, but NO3–N was the most responsive to N rate, with corresponding reductions in the DON/TDN ratio and increases in the nitrate/ammonium ratio. Nitrate‐N may be the best indicator for fate of anthropogenic N inputs, but studies focusing only on NO3–N are likely underreporting N exports.
Networks of materials: Construction and structural analysis
Authors: Veremyev Alexander , Liyanage Laalitha , Fornari Marco , Boginski Vladimir , Curtarolo Stefano , Butenko Sergiy , Buongiorno Nardelli Marco 
Published: September 2020

AbstractModeling and analysis of the materials universe is an emerging area of research with many important applications in materials science. The main goal is to create a map of materials which allows not only to visualize and navigate the materials space, but also reveal complex relationships and “connections” among materials and potentially find clusters of materials with similar properties. In this paper, we consider the problem of mapping and exploring the materials universe using network science tools and concepts. The networks are based on the open‐source materials data repository AFLOW.org where each material is represented as a node, and each pair of nodes is connected by a link if the respective materials exhibit a high level of similarity between their Density of States (DOS) functions. We discuss the importance of similarity measure selection, investigate basic structural properties of the resulting networks, and demonstrate advantages and limitations of the proposed approaches. Materials networks, similarity measures, DOS function, materials informatics, network analysis, clique.
Demand‐based optimization of a chlorobenzene process with high‐fidelity and surrogate reactor models under trust region strategies
Authors: Yoshio Noriyuki , Biegler Lorenz T. 
Published: September 2020

AbstractThis work demonstrates the optimization of the industrial scale chlorobenzene process, which continuously produces multiple products and includes a multiphase reaction with bubble column reactors (BCRs). The trust region filter (TRF) method is applied to carry out the demand‐based optimization of large chlorobenzene process with high‐fidelity BCR models. The TRF method uses surrogate models that substitute the high‐fidelity BCR models in the process model, and avoids the direct implementation of high‐fidelity models, which leads to a large and intractable optimization problem. The surrogate models are constructed based on basis functions that apply first order corrections from the gradients of high‐fidelity models. Different basis functions, CSTR and linear models, are studied in this work. As a result, the usage of CSTR models for the basis function leads to fewer function evaluations of the high‐fidelity model because CSTR model is a reasonable approximation of the high‐fidelity models and an initial guess of the optimization problem. Also, the TRF with surrogate models successfully provides an optimal solution of the high‐fidelity process model with few iterations and function evaluations of the high‐fidelity model itself. From the comparison with a low‐fidelity CSTR model, the solution with the TRF presents more accurate results. The surrogate approaches also make a smooth transition from low‐ to high‐fidelity models in process development. We apply this approach to a demand‐based optimization that integrates nontrivial business options, including optimal shortage of customer demands for profitable operation.
Heat exchanger network synthesis with detailed exchanger designs—2. Hybrid optimization strategy for synthesis of heat exchanger networks
Authors: Kazi Saif R. , Short Michael , Isafiade Adeniyi J. , Biegler Lorenz T. 
Published: September 2020

AbstractWe propose a new strategy to synthesize heat exchanger networks with detailed designs of individual heat exchangers. The proposed strategy uses a multistep approach by first obtaining a heat exchanger network topology through solving a modified version of the mixed integer nonlinear programming (MINLP) stage‐wise superstructure of Yee and Grossmann, which includes a smoothed LMTD approximation and pressure drops. In a second nonlinear programming (NLP) suboptimization step, we allow for nonisothermal mixing to solve problems with or without exchanger bypasses. The selected heat exchangers along with the mass and energy balances obtained are then used to design the network with detailed exchanger designs through solving a sequence of NLPs for individual heat exchanger designs. The NLPs are based on the detailed discretized optimization models of Kazi et al., which solve quickly and reliably to obtain heat exchangers based on rigorous, first‐principles derived coupled differential equations. These models solve a differential algebraic equation system and do not rely on usual assumptions associated with other heuristic‐based exchanger design methods, such as log mean temperature difference and FT correction factors. These detailed exchanger designs are then used to update the network optimization model through sets of correction factors on heat exchanger area, number of shells, heat transfer coefficients, and pressure drops of each exchanger design, in a method based on that of Short et al. The method solves reliably, guaranteeing feasible exchangers for every potential network generated by the shortcut models, through validation with rigorous heat exchanger models at every iteration. In addition, the method does not increase the nonlinearity of the MINLP model, nor does it require any manual intervention or initialization from the user. Three examples are solved and the results are compared to those obtained in the literature.
Optimal design of water pipeline networks for the development of shale gas resources
Authors: Cafaro Diego C. , Grossmann Ignacio 
Published: September 2020

AbstractOne of the major concerns in shale gas production is water management. Millions of gallons of water are injected to fracture each well and a significant amount returns to the surface as flowback. Operators are increasingly reusing flowback to reduce freshwater consumption and impaired water disposal. Because of this, networks of water pipelines in U.S. shales are growing fast. This work is aimed at addressing the optimal planning of shale gas operations in multiple wellpads together with the design of water distribution networks (WDN). We propose a multiperiod mixed‐integer linear programming model to solve the challenging stay‐or‐mobilize trade‐off. The proposed model permits to schedule operations at a detailed level, accounting for the WDN required to maximize the reuse of impaired water. We present illustrative examples involving up to 20 pads, 4 frac‐crews, and 100 wells developed over 1 year, showing that the design of the WDN can be effectively optimized.
A Facile C‐H Insertion Strategy using Combination of HFIP and Isocyanides: Metal‐Free Access to Azole Derivatives
Authors: Gujjarappa Raghuram , Vodnala Nagaraju , Reddy Velma Ganga , Malakar Chandi C. 
Published: September 2020

AbstractAn efficient metal‐free approach has been devised towards the synthesis of azoles via C−H insertion protocol. Various isocyanides were examined as effective C1‐synthons. The HFIP plays crucial role as hydrogen source and promoter of the reaction in order to reveal the maximum efficacies to accomplish the transformation in high yields of the products with excellent functional group tolerance. The control experiment affirmed 83% of deuterium incorporation, when the reaction was performed using HFIP‐d2.