bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nightside Detection of a Large‐Scale Thermospheric Wave Generated by a Solar Eclipse
Authors: Harding B. J. , Drob D. P. , Buriti R. A. , Makela J. J. 
Published: March 2018

AbstractThe generation of a large‐scale wave in the upper atmosphere caused by a solar eclipse was first predicted in the 1970s, but the experimental evidence remains sparse and comprises mostly indirect observations. This study presents observations of the wind component of a large‐scale thermospheric wave generated by the 21 August 2017 total solar eclipse. In contrast with previous studies, the observations are made on the nightside, after the eclipse ended. A ground‐based interferometer located in northeastern Brazil is used to monitor the Doppler shift of the 630.0‐nm airglow emission, providing direct measurements of the wind and temperature in the thermosphere, where eclipse effects are expected to be the largest. A disturbance is seen in the zonal and meridional wind which is at or above the 90% significance level based on the measured 30‐day variability. These observations are compared with a first principles numerical model calculation from the Thermosphere‐Ionosphere‐Mesosphere‐Electrodynamics General Circulation Model, which predicted the propagation of a large‐scale wave well into the nightside. The modeled disturbance matches well the difference between the wind measurements and the 30‐day median, though the measured perturbation (∼60 m/s) is larger than the prediction (38 m/s) for the meridional wind. No clear evidence for the wave is seen in the temperature data, however.
Type‐Dependent Responses of Ice Cloud Properties to Aerosols From Satellite Retrievals
Authors: Zhao Bin , Gu Yu , Liou Kuo‐Nan , Wang Yuan , Liu Xiaohong , Huang Lei , Jiang Jonathan H. , Su Hui 
Published: March 2018

AbstractAerosol‐cloud interactions represent one of the largest uncertainties in external forcings on our climate system. Compared with liquid clouds, the observational evidence for the aerosol impact on ice clouds is much more limited and shows conflicting results, partly because the distinct features of different ice cloud and aerosol types were seldom considered. Using 9‐year satellite retrievals, we find that, for convection‐generated (anvil) ice clouds, cloud optical thickness, cloud thickness, and cloud fraction increase with small‐to‐moderate aerosol loadings (<0.3 aerosol optical depth) and decrease with further aerosol increase. For in situ formed ice clouds, however, these cloud properties increase monotonically and more sharply with aerosol loadings. An increase in loading of smoke aerosols generally reduces cloud optical thickness of convection‐generated ice clouds, while the reverse is true for dust and anthropogenic pollution aerosols. These relationships between different cloud/aerosol types provide valuable constraints on the modeling assessment of aerosol‐ice cloud radiative forcing.
Investigating Source Contributions of Size‐Aggregated Aerosols Collected in Southern Ocean and Baring Head, New Zealand Using Sulfur Isotopes
Authors: Li Jianghanyang , Michalski Greg , Davy Perry , Harvey Mike , Katzman Tanya , Wilkins Benjamin 
Published: March 2018

AbstractMarine sulfate aerosols in the Southern Ocean are critical to the global radiation balance, yet the sources of sulfate and their seasonal variations are unclear. We separately sampled marine and ambient aerosols at Baring Head, New Zealand for 1 year using two collectors and evaluated the sources of sulfate in coarse (1–10 μm) and fine (0.05–1 μm) aerosols using sulfur isotopes (δ34S). In both collectors, sea‐salt sulfate (SO42−SS) mainly existed in coarse aerosols and nonsea‐salt sulfate (SO42−NSS) dominated the sulfate in fine aerosols, although some summer SO42−NSS appeared in coarse particles due to aerosol coagulation. SO42−NSS in the marine aerosols was mainly (88–100%) from marine biogenic dimethylsulfide (DMS) emission, while the SO42−NSS in the ambient aerosols was a combination of DMS (73–79%) and SO2 emissions from shipping activities (~21–27%). The seasonal variations of SO42−NSS concentrations inferred from the δ34S values in both collectors were mainly controlled by the DMS flux.
Correlation Between Fracture Network Properties and Stress Variability in Geological Media
Authors: Lei Qinghua , Gao Ke 
Published: March 2018

AbstractWe quantitatively investigate the stress variability in fractured geological media under tectonic stresses. The fracture systems studied include synthetic fracture networks following power law length scaling and natural fracture patterns based on outcrop mapping. The stress field is derived from a finite‐discrete element model, and its variability is analyzed using a set of mathematical formulations that honor the tensorial nature of stress data. We show that local stress perturbation, quantified by the Euclidean distance of a local stress tensor to the mean stress tensor, has a positive, linear correlation with local fracture intensity, defined as the total fracture length per unit area within a local sampling window. We also evaluate the stress dispersion of the entire stress field using the effective variance, that is, a scalar‐valued measure of the overall stress variability. The results show that a well‐connected fracture system under a critically stressed state exhibits strong local and global stress variabilities.
53–43 Ma Deformation of Eastern Tibet Revealed by Three Stages of Tectonic Rotation in the Gongjue Basin
Authors: Zhang Yang , Huang Wentao , Huang Baochun , van Hinsbergen Douwe J. J. , Yang Tao , Dupont-Nivet Guillaume , Guo Zhaojie 
Published: March 2018

AbstractThe Gongjue basin from the eastern Qiangtang terrane is located in the transition region where the regional structural lineation curves from east‐west‐oriented in Tibet to north‐south‐oriented in Yunnan. In this study, we sampled the red beds in the basin from the lower Gongjue to upper Ranmugou formations for the first time covering the entire stratigraphic profile. The stratigraphic ages are bracketed within 53–43 Ma by new detrital zircon U‐Pb ages constraining the maximum deposition age to 52.5 ± 1.5 Ma. Rock magnetic and petrographic studies indicate that detrital magnetite and hematite are the magnetic carriers. Positive reversals and fold tests demonstrate that the characteristic remanent magnetization has a primary origin. The Gongjue and Ranmugou formations yield mean characteristic remanent magnetization directions of Ds/Is = 31.0°/21.3° and Ds/Is = 15.9°/22.0°, respectively. The magnetic inclination of these characteristic remanent magnetizations is significantly shallowed compared to the expected inclination for the locality. However, the elongation/inclination correction method does not provide a meaningful correction, likely because of syn‐depositional rotation. Rotations relative to the Eurasian apparent polar wander path occurred in three stages: Stage I, 33.3 ± 3.4° clockwise rotation during the deposition of the Gongjue and lower Ranmugou formations; Stage II, 26.9 ± 3.7° counterclockwise rotation during deposition of the lower and middle Ranmugou formation; and Stage III, 17.7 ± 3.3° clockwise rotation after 43 Ma. The complex rotation history recorded in the basin is possibly linked to sinistral shear along the Qiangtang block during India indentation into Asia and the early stage of the extrusion of the northwestern Indochina blocks away from eastern Tibet.
Heterogeneous N2O5 Uptake During Winter: Aircraft Measurements During the 2015 WINTER Campaign and Critical Evaluation of Current Parameterizations
Authors: McDuffie Erin E. , Fibiger Dorothy L. , Dubé William P. , Lopez‐Hilfiker Felipe , Lee Ben H. , Thornton Joel A. , Shah Viral , Jaeglé Lyatt , Guo Hongyu , Weber Rodney J. , Michael Reeves J. , Weinheimer Andrew J. , Schroder Jason C. , Campuzano‐Jost Pedro , Jimenez Jose L. , Dibb Jack E. , Veres Patrick , Ebben Carly , Sparks Tamara L. , Wooldridge Paul J. , Cohen Ronald C. , Hornbrook Rebecca S. , Apel Eric C. , Campos Teresa , Hall Samuel R. , Ullmann Kirk , Brown Steven S. 
Published: March 2018

AbstractNocturnal dinitrogen pentoxide (N2O5) heterogeneous chemistry impacts regional air quality and the distribution and lifetime of tropospheric oxidants. Formed from the oxidation of nitrogen oxides, N2O5 is heterogeneously lost to aerosol with a highly variable reaction probability, γ(N2O5), dependent on aerosol composition and ambient conditions. Reaction products include soluble nitrate (HNO3 or NO3−) and nitryl chloride (ClNO2). We report the first‐ever derivations of γ(N2O5) from ambient wintertime aircraft measurements in the critically important nocturnal residual boundary layer. Box modeling of the 2015 Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER) campaign over the eastern United States derived 2,876 individual γ(N2O5) values with a median value of 0.0143 and range of 2 × 10−5 to 0.1751. WINTER γ(N2O5) values exhibited the strongest correlation with aerosol water content, but weak correlations with other variables, such as aerosol nitrate and organics, suggesting a complex, nonlinear dependence on multiple factors, or an additional dependence on a nonobserved factor. This factor may be related to aerosol phase, morphology (i.e., core shell), or mixing state, none of which are commonly measured during aircraft field studies. Despite general agreement with previous laboratory observations, comparison of WINTER data with 14 literature parameterizations (used to predict γ(N2O5) in chemical transport models) confirms that none of the current methods reproduce the full range of γ(N2O5) values. Nine reproduce the WINTER median within a factor of 2. Presented here is the first field‐based, empirical parameterization of γ(N2O5), fit to WINTER data, based on the functional form of previous parameterizations.
Tuning Electrical and Thermal Transport in AlGaN/GaN Heterostructures via Buffer Layer Engineering
Authors: Yalamarthy Ananth Saran , So Hongyun , Muñoz Rojo Miguel , Suria Ateeq J. , Xu Xiaoqing , Pop Eric , Senesky Debbie G. 
Published: March 2018

AbstractProgress in wide bandgap, III–V material systems based on gallium nitride (GaN) has enabled the realization of high‐power and high‐frequency electronics. Since the highly conductive, 2D electron gas (2DEG) at the aluminum gallium nitride (AlGaN)/GaN interface is based on built‐in polarization fields and is confined to nanoscale thicknesses, its charge carriers exhibit much higher mobilities compared to their doped counterparts. This study shows that such 2DEGs also offer the unique ability to manipulate electrical transport separately from thermal transport, through the examination of fully suspended AlGaN/GaN diaphragms of varied GaN buffer layer thickness. Notably, ≈100 nm thin GaN layers can considerably impede heat flow without electrical transport degradation. These achieve 4× improvement in the thermoelectric figure of merit (zT) over externally doped GaN, with state‐of‐the‐art power factors of 4–7 mW m‐1 K‐2. The remarkable tuning behavior and thermoelectric enhancement, elucidated here for the first time in a polarization‐based heterostructure, are achieved because electrons are at the heterostructured interface, while phonons are within the material system. These results highlight the potential for using 2DEGs in III–V materials for on‐chip thermal sensing and energy harvesting.
Development of Graphene Oxide/Polyaniline Inks for High Performance Flexible Microsupercapacitors via Extrusion Printing
Authors: Liu Yuqing , Zhang Binbin , Xu Qun , Hou Yuyang , Seyedin Shayan , Qin Si , Wallace Gordon G. , Beirne Stephen , Razal Joselito M. , Chen Jun 
Published: March 2018

AbstractExtrusion printing of interdigitated electrodes for flexible microsupercapacitors (fMSCs) offers an attractive route to the fabrication of flexible devices where cost, scalability, and processability of ink formulations are critical. In this work, highly concentrated, viscous, and water‐dispersible inks are developed based on graphene oxide (GO)/polyaniline (PANi) composite for extrusion printing. The optimized GO/PANi‐based all‐solid‐state symmetric fMSCs obtained by extrusion printing interdigitated microelectrodes can deliver outstanding areal capacitance of 153.6 mF cm−2 and volumetric capacitance of 19.2 F cm−3 at 5 mV s−1. It is shown that by fabricating asymmetric fMSCs using the GO/PANi as positive electrode and a graphene‐based negative electrode, the voltage window can be widened from 0.8 to 1.2 V and improvements can be achieved in energy density (from 3.36 to 4.83 mWh cm−3), power density (from 9.82 to 25.3 W cm−3), and cycling stability (from 75% to 100% capacitance retention over 5000 cycles) compared with the symmetric counterpart. The simple ink preparation and facile device fabrication protocols reported here make the scalable fabrication of extrusion printed fMSCs a promising technology.
Quasi‐Stable Electroless Ni–P Deposition: A Pivotal Strategy to Create Flexible Li–S Pouch Batteries with Bench Mark Cycle Stability and Specific Capacity
Authors: Gou Jian , Zhang Hongzhang , Yang Xiaofei , Chen Yuqing , Yu Ying , Li Xianfeng , Zhang Huamin 
Published: March 2018

AbstractDevelopment of flexible Li–S batteries brings along the flourishing prospective for energy‐hungry wearable devices. However, it is still seriously restricted due to lack of facile methods to solve its inherent problems and flexible device‐related current collection issues. Herein, quasi‐stable electroless deposition method is firstly proposed to solve these problems by fabricating 3D tunable Ni–P networks in the C/S free‐standing electrode. The ultrathin Ni–P layers which are highly conductive and strongly adhesive with electrode substrates improve the electronic conductivity by two orders of magnitude and rise initial specific capacity from 1200 to 1600 mAh g−1. The harmful shuttle effect of polysulfide is also effectively alleviated due to the chemical adsorption and physical sieving properties of the 3D networks. The flexible pouch Li–S batteries assembled with commercially applicable structure also show high flexibility and as high as 1420 mAh g−1 output capacity at 0.1C in cycling test. This method can definitely be extended to other flexible devices such as Li‐ion batteries, Li–O2 batteries, and supercapacitors.
Self‐Limited Epitaxial Growth of Ultrathin Nonlayered CdS Flakes for High‐Performance Photodetectors
Authors: Jin Bao , Huang Pu , Zhang Qi , Zhou Xing , Zhang Xiuwen , Li Liang , Su Jianwei , Li Huiqiao , Zhai Tianyou 
Published: March 2018

Abstract2D nonlayered materials that possess appealing properties are entering the researchers' vision. However, direct access to the 2D level of these materials is still a great challenge due to the instrinsic isotropic chemical bond. This work presents the initially self‐limited epitaxial growth of ultrathin nonlayered CdS flakes (as thin as 6 nm) on mica substrate with a large domain size (>40 µm) by employing In2S3 as the passivation agent. Besides, the thickness and sizes of the products could be tunable by the addition level of In2S3 amount. The growth mechanism is evidenced via experiments and theoretical calculations, which is attributed to the surface distortion effect of In–S motif and the preference of local environments for In on the CdS (0001) surface. The photodetector designed on CdS flake demonstrates a high photoswitching ratio (up to 103), a high detectivity (D* ≈ 2.71 × 109 Jones), and fast photoresponse speed (τR = 14 ms, τD = 8 ms). The as‐proposed self‐limited epitaxial growth method opens a new avenue to synthetize 2D nonlayered materials and will promote their further applications in novel optoelectronic devices.
Microwave Combustion for Rapidly Synthesizing Pore‐Size‐Controllable Porous Graphene
Authors: Wan Jun , Huang Liang , Wu Jiabin , Xiong Liukang , Hu Zhimi , Yu Huimin , Li Tianqi , Zhou Jun 
Published: March 2018

AbstractPorous graphene has been widely applied in energy storage, electrocatalysis, photoelectron devices, etc. However, the producing process for porous graphene usually needs long time and is a tedious step. In this work, porous graphene is prepared with controllable pore size by using active metal nanoparticles to catalytically oxidize carbon under microwave combustion process within tens of seconds. The ion exchange membrane based on porous graphene with ≈5 nm pore diameter exhibits a great performance for salinity gradient power generation application with a power density output of ≈1.15 W m−2. This work highlights a new strategy for the design and synthesis of pore‐size‐controllable porous graphene and provides new opportunities for 2D porous nanomaterials.
Remarkable Acid Stability of Polypyrrole‐MoS4: A Highly Selective and Efficient Scavenger of Heavy Metals Over a Wide pH Range
Authors: Xie Linxia , Yu Zihuan , Islam Saiful M. , Shi Keren , Cheng Yahan , Yuan Mengwei , Zhao Jing , Sun Genban , Li Huifeng , Ma Shulan , Kanatzidis Mercouri G. 
Published: March 2018

AbstractThe new material polypyrrole/MoS42−(MoS4‐Ppy), prepared by ion‐exchange of NO3‐ of NO3‐Ppy with MoS42−, displays high acid stability and excellent uptake for heavy metal ions such as Hg2+, Ag+, Cu2+, and Pb2+. The different maximum adsorption capacities (qm) for Cu2+, Pb2+, Hg2+, and Ag+ depend on the various binding modes arising from the different thiophilicity of these metal ions. The removals of Ag+ and Pb2+ reach >99.6% within 5 min, and for highly toxic Hg2+, >98% removal achieves at 1 min. At strong acid limit, the exceptional qm(Ag+) of 725 mg g−1 places the MoS4‐Ppy at the top of materials for such removal. Uptake kinetics of Ag+, Hg2+, and Pb2+ is extremely fast: >99.9% removal rates at wide pH range (0.5–6) within 1–5 min. Also, at strongly acidic conditions (pH ≈ 1), for highly toxic Hg2+, <2 ppb concentration can be achieved, accepted as safe limit. The MoS4‐Ppy demonstrates an outstanding ability to separate low‐concentrated Ag+ from high concentrated Cu2+ especially under strong acidic conditions (pH ≈ 1), showing a large separation factor SFAg/Cu (KdAg/KdCu) of 105 (>100). MoS4‐Ppy is a superior and novel sorbent material for water remediation applications as well as precious metals recovery.
Substitutional Carbon‐Modified Anatase TiO2 Decahedral Plates Directly Derived from Titanium Oxalate Crystals via Topotactic Transition
Authors: Niu Ping , Wu Tingting , Wen Lei , Tan Jun , Yang Yongqiang , Zheng Shijian , Liang Yan , Li Feng , Irvine John T. S. , Liu Gang , Ma Xiuliang , Cheng Hui‐Ming 
Published: March 2018

AbstractChanging the composition and/or structure of some metal oxides at the atomic level can significantly improve their performance in different applications. Although many strategies have been developed, the introduction of heteroatoms, particularly anions to the internal part of metal oxide particles, is still not adequate. Here, an effective strategy is demonstrated for directly preparing polycrystalline decahedral plates of substitutional carbon‐doped anatase TiO2 from titanium (IV) oxalate by a thermally induced topotactic transition in an inert atmosphere. Because of the carbon concentration gradient introduced in side of the plates, the carbon‐doped TiO2 (TiO2–xCx) shows an increased visible light absorption and a two orders of magnitude higher electrical conductivity than pure TiO2. Consequently, it can be used as a photocatalyst and an active material for lithium storage and shows much superior activity in generating hydroxyl radicals under visible light and greatly increased electrical‐specific capacity at high charge–discharge rates. The strategy developed could also be applicable to the atomic‐scale modification of other metal oxides.
Kirigami‐Inspired Nanoconfined Polymer Conducting Nanosheets with 2000% Stretchability
Authors: Guan Ying‐Shi , Zhang Zhuolei , Tang Yichao , Yin Jie , Ren Shenqiang 
Published: March 2018

AbstractStretchable conductors are essential components of wearable electronics. However, such materials typically sacrifice their electronic conductivity to achieve mechanical stretchability and elasticity. Here, the nanoconfinement and air/water interfacial assembly is explored to grow freestanding mechanical endurance conducting polymer nanosheets that can be stretched up to 2000% with simultaneously high electrical conductivity, inspired by kirigami. Such stretchable conductors show remarkable electronic and mechanical reversibility and reproducibility under more than 1000 cycle durability tests with 2000% deformability, which can be accurately predicted using finite element modeling. The conductivity of nanoconfined freestanding conductor nanosheets increases by three orders of magnitude from 2.2 × 10−3 to 4.002 S cm−1 is shown, due to the charge‐transfer complex formation between polymer chain and halogen, while the electrical conductance of the stretchable kirigami nanosheets can be maintained over the entire strain regime. The nanoconfined polymer nanosheets can also act as a sensor capable of sensing the pressure with high durability and real‐time monitoring.
Stimuli‐Driven Control of the Helical Axis of Self‐Organized Soft Helical Superstructures
Authors: Bisoyi Hari Krishna , Bunning Timothy J. , Li Quan 
Published: March 2018

AbstractSupramolecular and macromolecular functional helical superstructures are ubiquitous in nature and display an impressive catalog of intriguing and elegant properties and performances. In materials science, self‐organized soft helical superstructures, i.e., cholesteric liquid crystals (CLCs), serve as model systems toward the understanding of morphology‐ and orientation‐dependent properties of supramolecular dynamic helical architectures and their potential for technological applications. Moreover, most of the fascinating device applications of CLCs are primarily determined by different orientations of the helical axis. Here, the control of the helical axis orientation of CLCs and its dynamic switching in two and three dimensions using different external stimuli are summarized. Electric‐field‐, magnetic‐field‐, and light‐irradiation‐driven orientation control and reorientation of the helical axis of CLCs are described and highlighted. Different techniques and strategies developed to achieve a uniform lying helix structure are explored. Helical axis control in recently developed heliconical cholesteric systems is examined. The control of the helical axis orientation in spherical geometries such as microdroplets and microshells fabricated from these enticing photonic fluids is also explored. Future challenges and opportunities in this exciting area involving anisotropic chiral liquids are then discussed.
An Ultrastable Ionic Chemiresistor Skin with an Intrinsically Stretchable Polymer Electrolyte
Authors: Jin Ming Liang , Park Sangsik , Kim Jong‐Seon , Kwon Sung Hyun , Zhang Shuye , Yoo Min Seok , Jang Sungwoo , Koh Hyeong‐Jun , Cho Soo‐Yeon , Kim So Young , Ahn Chi Won , Cho Kilwon , Lee Seung Geol , Kim Do Hwan , Jung Hee‐Tae 
Published: March 2018

AbstractUltrastable sensing characteristics of the ionic chemiresistor skin (ICS) that is designed by using an intrinsically stretchable thermoplastic polyurethane electrolyte as a volatile organic compound (VOC) sensing channel are described. The hierarchically assembled polymer electrolyte film is observed to be very uniform, transparent, and intrinsically stretchable. Systematic experimental and theoretical studies also reveal that artificial ions are evenly distributed in polyurethane matrix without microscale phase separation, which is essential for implementing high reliability of the ICS devices. The ICS displays highly sensitive and stable sensing of representative VOCs (including toluene, hexane, propanal, ethanol, and acetone) that are found in the exhaled breath of lung cancer patients. In particular, the sensor is found to be fully operational even after being subjected to long‐term storage or harsh environmental conditions (relative humidity of 85% or temperature of 100 °C) or severe mechanical deformation (bending to a radius of curvature of 1 mm, or stretching strain of 100%), which can be an effective method to realize a human‐adaptive and skin‐attachable biosensor platform for daily use and early diagnosis.