bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geostatistical Analysis of Mesoscale Spatial Variability and Error in SeaWiFS and MODIS/Aqua Global Ocean Color Data
Authors: Glover David M. , Doney Scott C. , Oestreich William K. , Tullo Alisdair W. 
Published: December 2017

AbstractMesoscale (10–300 km, weeks to months) physical variability strongly modulates the structure and dynamics of planktonic marine ecosystems via both turbulent advection and environmental impacts upon biological rates. Using structure function analysis (geostatistics), we quantify the mesoscale biological signals within global 13 year SeaWiFS (1998–2010) and 8 year MODIS/Aqua (2003–2010) chlorophyll a ocean color data (Level‐3, 9 km resolution). We present geographical distributions, seasonality, and interannual variability of key geostatistical parameters: unresolved variability or noise, resolved variability, and spatial range. Resolved variability is nearly identical for both instruments, indicating that geostatistical techniques isolate a robust measure of biophysical mesoscale variability largely independent of measurement platform. In contrast, unresolved variability in MODIS/Aqua is substantially lower than in SeaWiFS, especially in oligotrophic waters where previous analysis identified a problem for the SeaWiFS instrument likely due to sensor noise characteristics. Both records exhibit a statistically significant relationship between resolved mesoscale variability and the low‐pass filtered chlorophyll field horizontal gradient magnitude, consistent with physical stirring acting on large‐scale gradient as an important factor supporting observed mesoscale variability. Comparable horizontal length scales for variability are found from tracer‐based scaling arguments and geostatistical decorrelation. Regional variations between these length scales may reflect scale dependence of biological mechanisms that also create variability directly at the mesoscale, for example, enhanced net phytoplankton growth in coastal and frontal upwelling and convective mixing regions. Global estimates of mesoscale biophysical variability provide an improved basis for evaluating higher resolution, coupled ecosystem‐ocean general circulation models, and data assimilation.
Biogeochemistry of Dimethylsulfide, Dimethylsulfoniopropionate, and Acrylic Acid in the Changjiang Estuary and the East China Sea
Authors: Wu Xi , Li Pei‐Feng , Liu Chun‐Ying , Zhang Hong‐Hai , Yang Gui‐Peng , Zhang Sheng‐Hui , Zhu Mao‐Xu 
Published: December 2017

AbstractThe distributions of dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP), and acrylic acid (AA) were investigated in the Changjiang Estuary during winter (dry season) and summer (wet season) 2014 and in the East China Sea (ECS) during summer 2015. The rates of dissolved DMSP (DMSPd) degradation with DMS and AA production, DMS degradation, and AA degradation in the ECS were also studied. Significant seasonal variations in DMS(P) and AA concentrations were observed in the Changjiang Estuary with higher values during the wet season than during the dry season. The maximum ratio of AA/chlorophyll a (Chl a) occurred at the mouth of the Changjiang Estuary due to the combined effects of production from DMSP and terrestrial inputs from the Changjiang Estuary. The distributions of DMS(P) and AA in the ECS were dramatically influenced by the Kuroshio Current and the upwelling caused by the Taiwan Warm Current. The ratios of DMS(P)/Chl a and AA/Chl a exhibited similar patterns in the surface seawater of the ECS, which indicated that phytoplankton species and biomass might play important roles in controlling the distributions of DMS(P) and AA. In vertical profiles, high values of AA emerged in the upper water column and bottom seawater of the Changjiang Estuary. Meanwhile, the maxima of DMS(P) and AA generally appeared in the surface or euphotic layer, whereas their minima arose in the bottom seawater of the ECS. The degradation rates of DMSPd, DMS, and AA in the inshore waters were higher than those in the open sea.
Evolution of the North Pacific Subtropical Mode Water in Anticyclonic Eddies
Authors: Xu Lixiao , Xie Shang‐Ping , Liu Qinyu , Liu Cong , Li Peiliang , Lin Xiaopei 
Published: December 2017

AbstractAnticyclonic eddies (AEs) trap and transport the North Pacific subtropical mode water (STMW), but the evolution of the STMW trapped in AEs has not been fully studied due to the lack of eddy‐tracking subsurface observations. Here we analyze profiles from special‐designed Argo floats that follow two STMW‐trapping AEs for more than a year. The enhanced daily sampling by these Argo floats swirling around the eddies enables an unprecedented investigation into the structure and evolution of the trapped STMW. In the AEs, the upper (lower) thermocline domes up (concaves downward), and this lens‐shaped double thermocline encompasses the thick STMW within the eddy core. The lighter STMW (25.0 ∼ 25.2 σθ) trapped in AEs dissipates quickly after the formation in winter because of the deepening seasonal thermocline, but the denser STMW (25.2 ∼ 25.4 σθ) remains largely unchanged except when the AE passes across the Izu Ridge. The enhanced diapycnal mixing over the ridge weakens the denser STMW appreciably. While many AEs decay upon hitting the ridge, some pass through a bathymetric gap between the Hachijojima and Bonin Islands, forming a cross‐ridge pathway for STMW transport. By contrast, the North Pacific Intermediate Water (NPIW) underneath is deeper than the eddy trapping depth (600 m), and hence left behind east of the Izu Ridge. In Argo climatology, the shallow STMW (< 400 m) intrudes through the gap westward because of the eddy transport, while the NPIW (800 m) is blocked by the Izu Ridge.
Tropical Cyclone‐Driven Sediment Dynamics Over the Australian North West Shelf
Authors: Dufois François , Lowe Ryan J. , Branson Paul , Fearns Peter 
Published: December 2017

AbstractOwing to their strong forcing at the air‐sea interface, tropical cyclones are a major driver of hydrodynamics and sediment dynamics of continental shelves, strongly impacting marine habitats and offshore industries. Despite the North West Shelf of Australia being one of the most frequently impacted tropical cyclone regions worldwide, there is limited knowledge of how tropical cyclones influence the sediment dynamics of this shelf region, including the significance of these episodic extreme events to the normal background conditions that occur. Using an extensive 2 year data set of the in situ sediment dynamics and 14 yearlong calibrated satellite ocean‐color data set, we demonstrate that alongshore propagating cyclones are responsible for simultaneously generating both strong wave‐induced sediment resuspension events and significant southwestward subtidal currents. Over the 2 year study period, two particular cyclones (Iggy and Narelle) dominated the sediment fluxes resulting in a residual southwestward sediment transport over the southern part of the shelf. By analyzing results from a long‐term (37 year) wind and wave hindcast, our results suggest that at least 16 tropical cyclones had a strong potential to contribute to that southwestward sediment pathway in a similar way to Iggy and Narelle.
Lightning Forcing in Global Fire Models: The Importance of Temporal Resolution
Authors: Felsberg A. , Kloster S. , Wilkenskjeld S. , Krause A. , Lasslop G. 
Published: December 2017

AbstractIn global fire models, lightning is typically prescribed from observational data with monthly mean temporal resolution while meteorological forcings, such as precipitation or temperature, are prescribed in a daily resolution. In this study, we investigate the importance of the temporal resolution of the lightning forcing for the simulation of burned area by varying from daily to monthly and annual mean forcing. For this, we utilize the vegetation fire model JSBACH‐SPITFIRE to simulate burned area, forced with meteorological and lightning data derived from the general circulation model ECHAM6. On a global scale, differences in burned area caused by lightning forcing applied in coarser temporal resolution stay below 0.55% compared to the use of daily mean forcing. Regionally, however, differences reach up to 100%, depending on the region and season. Monthly averaged lightning forcing as well as the monthly lightning climatology cause differences through an interaction between lightning ignitions and fire prone weather conditions, accounted for by the fire danger index. This interaction leads to decreased burned area in the boreal zone and increased burned area in the Tropics and Subtropics under the coarser temporal resolution. The exclusion of interannual variability, when forced with the lightning climatology, has only a minor impact on the simulated burned area. Annually averaged lightning forcing causes differences as a direct result of the eliminated seasonal characteristics of lightning. Burned area is decreased in summer and increased in winter where fuel is available. Regions with little seasonality, such as the Tropics and Subtropics, experience an increase in burned area.
A new kernel RLS algorithm for systems with bounded noise
Authors: Constantin I. , Constantin J. , Bigand A. 
Published: December 2017

SummaryIn this paper, we propose a new nonlinear set‐membership recursive least‐squares algorithm. The algorithm draws on a linear set‐membership filter in conjunction with kernels for nonlinear processing. Set‐membership algorithms exploit a priori model information that directly, or indirectly, prescribes dynamic constraints on the solution space. Such information is disregarded by conventional approaches. Kernel methods provide an implicit mapping of the data in a high‐dimensional feature space where linear techniques are applied. Computations are done in the initial space by means of kernel functions. In this work, we develop a kernel‐based version of a set‐membership filter that belongs to a class of optimal bounding ellipsoid algorithms. Optimal bounding ellipsoid algorithms compute ellipsoidal approximations to regions in the parameter space that are consistent with the observed data and the model assumptions. Experiments involving stationary and nonstationary data are presented. Compared with existing kernel adaptive algorithms, the proposed algorithm offers an enhanced performance and sparsity, conjugated with better tracking capabilities.
On the need of projections in input‐error model reference adaptive control
Authors: Barabanov Nikita , Ortega Romeo 
Published: December 2017

SummaryThe main objective of this note is to contribute, if modestly, toward the understanding of the input‐error model reference adaptive control scheme revealing an instability mechanism that arises if the projection of the plant high‐frequency gain coefficient estimate is omitted. In addition, a self‐contained proof of global convergence of the scheme with the projections for a simple first‐order plant is given.
Toward Stretchable Self‐Powered Sensors Based on the Thermoelectric Response of PEDOT:PSS/Polyurethane Blends
Authors: Taroni Prospero J. , Santagiuliana Giovanni , Wan Kening , Calado Philip , Qiu Manting , Zhang Han , Pugno Nicola M. , Palma Matteo , Stingelin‐Stutzman Natalie , Heeney Martin , Fenwick Oliver , Baxendale Mark , Bilotti Emiliano 
Published: December 2017

AbstractThe development of new flexible and stretchable sensors addresses the demands of upcoming application fields like internet‐of‐things, soft robotics, and health/structure monitoring. However, finding a reliable and robust power source to operate these devices, particularly in off‐the‐grid, maintenance‐free applications, still poses a great challenge. The exploitation of ubiquitous temperature gradients, as the source of energy, can become a practical solution, since the recent discovery of the outstanding thermoelectric properties of a conductive polymer, poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS). Unfortunately the use of PEDOT:PSS is currently constrained by its brittleness and limited processability. Herein, PEDOT:PSS is blended with a commercial elastomeric polyurethane (Lycra), to obtain tough and processable self‐standing films. A remarkable strain‐at‐break of ≈700% is achieved for blends with 90 wt% Lycra, after ethylene glycol treatment, without affecting the Seebeck voltage. For the first time the viability of these novel blends as stretchable self‐powered sensors is demonstrated.
Selective Surface Enhanced Raman Scattering for Quantitative Detection of Lung Cancer Biomarkers in Superparticle@MOF Structure
Authors: Qiao Xuezhi , Su Bensheng , Liu Cong , Song Qian , Luo Dan , Mo Guang , Wang Tie 
Published: December 2017

AbstractSurface enhanced Raman scattering (SERS) is a trace detection technique that extends even to single molecule detection. Its potential application to the noninvasive recognition of lung malignancies by detecting volatile organic compounds (VOCs) that serve as biomarkers would be a breakthrough in early cancer diagnostics. This application, however, is currently limited by two main factors: (1) most VOC biomarkers exhibit only weak Raman scattering; and (2) the high mobility of gaseous molecules results in a low adsorptivity on solid substrates. To enhance the adsorption of gaseous molecules, a ZIF‐8 layer is coated onto a self‐assembly of gold superparticles (GSPs) in order to slow the flow rate of gaseous biomarkers and depress the exponential decay of the electromagnetic field around the GSP surfaces. Gaseous aldehydes that are released as a result of tumor‐specific tissue composition and metabolism, thereby acting as indicators of lung cancer, are guided onto SERS‐active GSPs substrates through a ZIF‐8 channel. Through a Schiff base reaction with 4‐aminothiophenol pregrafted onto gold GSPs, gaseous aldehydes are captured with a 10 ppb limit of detection, demonstrating tremendous prospects for in vitro diagnoses of early stage lung cancer.
Controllable Solid Electrolyte Interphase in Nickel‐Rich Cathodes by an Electrochemical Rearrangement for Stable Lithium‐Ion Batteries
Authors: Kim Junhyeok , Lee Jieun , Ma Hyunsoo , Jeong Hu Young , Cha Hyungyeon , Lee Hyomyung , Yoo Youngshin , Park Minjoon , Cho Jaephil 
Published: December 2017

AbstractThe layered nickel‐rich materials have attracted extensive attention as a promising cathode candidate for high‐energy density lithium‐ion batteries (LIBs). However, they have been suffering from inherent structural and electrochemical degradation including severe capacity loss at high electrode loading density (>3.0 g cm−3) and high temperature cycling (>60 °C). In this study, an effective and viable way of creating an artificial solid–electrolyte interphase (SEI) layer on the cathode surface by a simple, one‐step approach is reported. It is found that the initial artificial SEI compounds on the cathode surface can electrochemically grow along grain boundaries by reacting with the by‐products during battery cycling. The developed nickel‐rich cathode demonstrates exceptional capacity retention and structural integrity under industrial electrode fabricating conditions with the electrode loading level of ≈12 mg cm−2 and density of ≈3.3 g cm−3. This finding could be a breakthrough for the LIB technology, providing a rational approach for the development of advanced cathode materials.
Single‐Site AuI Catalyst for Silane Oxidation with Water
Authors: Chen Zheng , Zhang Qi , Chen Wenxing , Dong Juncai , Yao Hurong , Zhang Xiangbo , Tong Xuanjue , Wang Dingsheng , Peng Qing , Chen Chen , He Wei , Li Yadong 
Published: December 2017

AbstractSingle‐site Au anchored on mpg‐C3N4 (519 ppm Au loading) is developed as a highly active, selective, and stable catalyst for the oxidation of silanes with water with a turnover frequency as high as 50 200 h−1, far exceeding most known catalysts based on total gold content. Other hydrosilanes bearing unsaturated functional groups also lead to corresponding silanols under mild reaction conditions without formation of any side products in good or excellent yields. The spherical aberration correction electron microscopy and extended X‐ray absorption fine structure measurements both confirm the atomic dispersion of Au atoms stabilized by mpg‐C3N4. The coordination of the catalytically active AuI by three nitrogen or carbon atoms in the tri‐s‐triazine repeating units not only prevents the Au atoms from aggregation, but also renders the surface AuI highly active, which is completely different than homogeneous AuI species.
Titanium Disulfide Coated Carbon Nanotube Hybrid Electrodes Enable High Energy Density Symmetric Pseudocapacitors
Authors: Zang Xining , Shen Caiwei , Kao Emmeline , Warren Roseanne , Zhang Ruopeng , Teh Kwok Siong , Zhong Junwen , Wei Minsong , Li Buxuan , Chu Yao , Sanghadasa Mohan , Schwartzberg Adam , Lin Liwei 
Published: December 2017

AbstractWhile electrochemical supercapacitors often show high power density and long operation lifetimes, they are plagued by limited energy density. Pseudocapacitive materials, in contrast, operate by fast surface redox reactions and are shown to enhance energy storage of supercapacitors. Furthermore, several reported systems exhibit high capacitance but restricted electrochemical voltage windows, usually no more than 1 V in aqueous electrolytes. Here, it is demonstrated that vertically aligned carbon nanotubes (VACNTs) with uniformly coated, pseudocapacitive titanium disulfide (TiS2) composite electrodes can extend the stable working range to over 3 V to achieve a high capacitance of 195 F g−1 in an Li‐rich electrolyte. A symmetric cell demonstrates an energy density of 60.9 Wh kg−1—the highest among symmetric pseudocapacitors using metal oxides, conducting polymers, 2D transition metal carbides (MXene), and other transition metal dichalcogenides. Nanostructures prepared by an atomic layer deposition/sulfurization process facilitate ion transportation and surface reactions to result in a high power density of 1250 W kg−1 with stable operation over 10 000 cycles. A flexible solid‐state supercapacitor prepared by transferring the TiS2–VACNT composite film onto Kapton tape is demonstrated to power a 2.2 V light emitting diode (LED) for 1 min.
3D Mesoporous van der Waals Heterostructures for Trifunctional Energy Electrocatalysis
Authors: Tang Cheng , Zhong Ling , Zhang Bingsen , Wang Hao‐Fan , Zhang Qiang 
Published: December 2017

AbstractThe emergence of van der Waals (vdW) heterostructures of 2D materials has opened new avenues for fundamental scientific research and technological applications. However, the current concepts and strategies of material engineering lack feasibilities to comprehensively regulate the as‐obtained extrinsic physicochemical characters together with intrinsic properties and activities for optimal performances. A 3D mesoporous vdW heterostructure of graphene and nitrogen‐doped MoS2 via a two‐step sequential chemical vapor deposition method is constructed. Such strategy is demonstrated to offer an all‐round engineering of 2D materials including the morphology, edge, defect, interface, and electronic structure, thereby leading to robustly modified properties and greatly enhanced electrochemical activities. The hydrogen evolution is substantially accelerated on MoS2, while the oxygen reduction and evolution are significantly improved on graphene. This work provides a powerful overall engineering strategy of 2D materials for electrocatalysis, which is also enlightening for other nanomaterials and energy‐related applications.
Rechargeable Aqueous Zinc‐Ion Battery Based on Porous Framework Zinc Pyrovanadate Intercalation Cathode
Authors: Xia Chuan , Guo Jing , Lei Yongjiu , Liang Hanfeng , Zhao Chao , Alshareef Husam N. 
Published: December 2017

AbstractIn this work, a microwave approach is developed to rapidly synthesize ultralong zinc pyrovanadate (Zn3V2O7(OH)2·2H2O, ZVO) nanowires with a porous crystal framework. It is shown that our synthesis strategy can easily be extended to fabricate other metal pyrovanadate compounds. The zinc pyrovanadate nanowires show significantly improved electrochemical performance when used as intercalation cathode for aqueous zinc–ion battery. Specifically, the ZVO cathode delivers high capacities of 213 and 76 mA h g−1 at current densities of 50 and 3000 mA g−1, respectively. Furthermore, the Zn//ZVO cells show good cycling stability up to 300 cycles. The estimated energy density of this Zn cell is ≈214Wh kg−1, which is much higher than commercial lead–acid batteries. Significant insight into the Zn‐storage mechanism in the pyrovanadate cathodes is presented using multiple analytical methods. In addition, it is shown that our prototype device can power a 1.5 V temperature sensor for at least 24 h.
Peptide Integrated Optics
Authors: Handelman Amir , Lapshina Nadezda , Apter Boris , Rosenman Gil 
Published: December 2017

AbstractBio‐nanophotonics is a wide field in which advanced optical materials, biomedicine, fundamental optics, and nanotechnology are combined and result in the development of biomedical optical chips. Silk fibers or synthetic bioabsorbable polymers are the main light‐guiding components. In this work, an advanced concept of integrated bio‐optics is proposed, which is based on bioinspired peptide optical materials exhibiting wide optical transparency, nonlinear and electrooptical properties, and effective passive and active waveguiding. Developed new technology combining bottom‐up controlled deposition of peptide planar wafers of a large area and top‐down focus ion beam lithography provides direct fabrication of peptide optical integrated circuits. Finding a deep modification of peptide optical properties by reconformation of biological secondary structure from native phase to β‐sheet architecture is followed by the appearance of visible fluorescence and unexpected transition from a native passive optical waveguiding to an active one. Original biocompatibility, switchable regimes of waveguiding, and multifunctional nonlinear optical properties make these new peptide planar optical materials attractive for application in emerging technology of lab‐on‐biochips, combining biomedical photonic and electronic circuits toward medical diagnosis, light‐activated therapy, and health monitoring.
Nanocomposite Capacitors with Significantly Enhanced Energy Density and Breakdown Strength Utilizing a Small Loading of Monolayer Titania
Authors: Wen Rongmei , Guo Junmeng , Zhao Chunlin , Liu Yanqing 
Published: December 2017

AbstractThe dielectric capacitor with high electric energy density is demanded for modern electronic and electrical power systems. However, their energy density is considerably limited by a low dielectric constant and low breakdown strength. Here, thin flexible polymer nanocomposites with high energy density are obtained by only adding a small loading of 2D monolayer titania along with concurrent improvements of dielectric constant and breakdown strength. This work not only first reveals that monolayer titania is an excellent filler that can be comparable to existing fillers in nanocomposite capacitors but also provides a facile approach to thin flexible compact dielectric films with ultrahigh energy density and breakdown strength for energy storage applications.