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A wideband planar multilayer filtering magic-T is proposed and developed. The proposed magic-T uses coupled microstrip slotlines (CMSs) and microstrip-slot transitions. With the orthogonality of even and odd modes of the CMS, the Chebyshev filtering responses of both the in-phase divider part (H-T) and out-of-phase divider part (E-T) are independent of each other. The microstrip-slot transitions act as a part of filtering structures to realize vertical transmission of energy. With equivalent impedance transformer models, the synthesis processes of a four-pole Chebyshev filtering H-T and a three-pole Chebyshev filtering E-T are derived and analyzed. To verify the proposed concept, a prototype with an operating center frequency of 3 GHz, a 100% equal ripple fractional bandwidth, and a different H-T and E-T in-band ripple are synthesized and implemented on a three-layer printed circuit board. The synthesized, simulated, and measured results show good agreements among them, verifying the feasibility of the proposed planar magic-T. [ABSTRACT FROM AUTHOR]

Exploring highly stable and active electrocatalyst for hydrogen evolution, oxygen evolution and oxygen reduction reactions is an unremitting target for the supply and storage of sustainable energies. Here, we report a type of oxygen vacancy-rich nanostructure in which uniform CoP/Co 3 O 4 nanoparticles (NPs) are coated and dispersed on an amorphous carbon network (pPVP). This hybrid nanostructure labeled as 'CoP/Co 3 O 4 -fC-pPVP' is synthesized by a pyrolysis-oxidation-phosphatization strategy, which can accelerate charge transfer and improve carrier separation owing to introducing copious oxygen vacancy. Benefiting from the modulated electronic structure and advantage of interfacial and synergistic effect among active CoP, Co 3 O 4 and pPVP layer, the CoP/Co 3 O 4 -fC-pPVP hybrid structure exhibits excellent trifunctional electrocatalytic performance. The scattering wave vector (q) of the samples before and after catalytic reactions remains unchanged from small angle X-ray scattering (SAXS) tests, indicating the stable phase structure. As for CoP/Co 3 O 4 -fC-pPVP, only a very low potential of 1.585 V is needed to reach 10 mA cm−2 in the overall water splitting process. Furthermore, the peak power density of CoP/Co 3 O 4 -fC-pPVP-based Zn-air batteries reaches 154 mW cm−2 and the charge-discharge voltage gap almost maintains the initial overpotential after 727 h cycle test. [ABSTRACT FROM AUTHOR]

A high-fidelity short-pulse monopulse antenna based on an extended Goubau line (EGL) is proposed, along with a novel time-domain analyzing and designing method. The monopulse antenna contains a simple feeding network and an EGL radiating structure, where the width of the single conductor is enlarged and a metal wall is constructed along the central line of the conductor. The antenna is actually a two-element array to form sum and difference patterns. Performances of the feeding structure and the EGL are almost independent of operating frequency, ensuring the antenna to transmit and receive short-pulse signals with high waveform fidelity. Angular information is obtained by analyzing the received pulses with the normalized Euclid distance (NED). The NED patterns are plotted to illustrate the angular information provided by the short-pulse monopulse operation. A null depth of 30 dB is obtained by the difference NED pattern for the short pulses with a spectrum from 4.2 to 11.8 GHz. The measured performance shows that the proposed short-pulse monopulse antenna has a promising prospect in directional detecting and tracking applications. [ABSTRACT FROM AUTHOR]

An exponential tapered post‐wall slotline antenna loaded with dielectric lens is proposed and demonstrated. The theoretical profile of the loaded dielectric lens is derived, and its physical explanation is presented. Besides, the proposed post‐wall structure in the antenna ensures low available characteristic impedance as well as low cross‐polarization levels of the antenna. The proposed antenna exhibits an 18.12 GHz impedance bandwidth between 1.88 and 20 GHz and a peak gain of 10.9 dBi. The measured E‐plane and H‐plane cross‐polarization level is −37.0 and − 26.0 dB in boresight direction, respectively. Compared to the antenna without dielectric lens, the average gain of the proposed antenna increases by 3 dB from 14 to 20 GHz, and the pulse peak‐peak gain increases by 1.59 dB, and the tailing signal levels is about 0.35 dB lower. [ABSTRACT FROM AUTHOR]

Novel resistor-free differential microstrip lines prototype loaded with lossy metamaterial is proposed to achieve wideband common-mode (CM) absorption. The metamaterial is constructed by a chain of lossy complementary split-ring resonators (CSRRs), which are etched on the ground plane. Different from the CM absorption realized by lumped resistors, this work utilizes the inherent dielectric and conductor losses introduced by the differential microstrip lines and CSRRs to absorb CM energy. Furthermore, CSRRs are designed with gradual perturbation to broaden the CM absorption band. The lossy even-mode equivalent circuit models are established and analyzed to reveal the CM absorption mechanism. In order to verify the proposed strategy to design resistor-free differential microstrip lines with CM absorption, a sample was fabricated and measured. The measured $S_{\mathrm {cc21}}$ and $S_{\mathrm {cc11}}$ are kept below −10 dB simultaneously from 4.3 to 5.65 GHz with 27.4% fractional bandwidth, where the CM energy is absorbed over 80% by the dielectric and conductor losses. Meanwhile, the low insertion loss of $S_{\mathrm {dd21}}$ below 6 GHz as well as the good differential-mode eye diagrams demonstrates that good signal integrity of differential signals is kept. [ABSTRACT FROM AUTHOR]

A novel phase corrected substrate integrated waveguide (SIW) H-plane horn antenna with embedded metal-via arrays is presented. The SIW horn is divided into four subhorns by three metal-via arrays inside the horn. A uniform phase distribution of EM field across the horn aperture is achieved by adjusting the lengths and positions of the metal-via arrays. The proposed horn antenna has a compact profile, and its simulated gain is 7.50 dBi at 35.5 GHz, whereas the simulated gain of a traditional horn antenna without the metal-via arrays is 6.38 dBi. When measured, the gain of the proposed horn antenna is 7.87 dBi at 35.5 GHz, whereas the gain of the traditional horn antenna is 5.58 dBi. Good agreement between the simulated and the measured results is obtained. [ABSTRACT FROM PUBLISHER]

Organic mudstone can be a high-quality source rock in petroleum basins. The accumulation patterns of various types of mudstone can also serve as a useful record of paleogeography. Due to the impact of tectonic movements, the East China Sea Basin (ECSB) saw its deposition setting transform from closed-lacustrine to open marine settings. This provides an opportunity to explore organic matter accumulation patterns within such a transformation setting. This study classified the constituent mudstones according to their differences in composition and sedimentary structure as follows: coaly mudstone or carbonaceous mudstone, calcareous mudstone, clayey mudstone, and siliceous mudstone. Considering the different sedimentary structures, siliceous mudstone can be subdivided into laminated, wavy, and slumped mudstones. Using integrated multiple indices of the paleo-environment, which includes clay mineral content, trace mineral content, and micro-paleontology assemblages, we reconstructed the paleography setting during the Paleocene and inferred that during this time, the ECSB was characterized by sedimentary differentiation. We discerned two different organic mudstone accumulation patterns by combining the results from rock-eval pyrolysis and paleo-environmental indices: 1) A closed-lacustrine mudstone accumulation pattern characterized by abundant sediment supply and dominated by allogenous mudstone formation by the flocculation process. The fresh to slightly salty water environment provided adequate nutrition to microorganisms and an appropriate temperature led to the increased accumulation of type II 1 and II 2 kerogen. 2) An open-marine mudstone accumulation pattern which revealed a sediment-starved setting. The flocculation process and fine-graded turbidities were the main processes leading to mudstone accumulation. More plants were concentrated in shallow water with declining salinity, leading to peat and mass carbon mudstone accumulation. • Classified the mudstone into six types according to its genesis difference. • Build the relationship between the paleo-environment and the abundance/types of organic matters. • Restore the mudstone distribution and the sedimentary facies association evolution process. • Put out the organic matter accumulation pattern in the transition setting. [ABSTRACT FROM AUTHOR]

For complex convergence movements between the Pacific Plate and Eurasian Plate since the Cenozoic, the East China Sea Basin (ECSB) presents a three-stage rifting movement: initial rifting, rifting development, and structural reversal stages. The ECSB changed from a closed lacustrine to an open marine source-to-sink (S2S) system and then returned to a semiopen bay S2S system. Recently, research has attracted more attention to the relationship between the depositional setting evolution and the corresponding source-to-sink patterns. This study determines that the early Paleocene was dominated by a closed lacustrine setting according to water salinities based on trace element and micropalaeontological assemblages. The middle Paleocene had an open marine setting, and the late Paleocene and Eocene had semiopen bay settings. In addition, we rebuild the provenance area of the S2S system with detrital zircon U Pb data and heavy mineral assemblage data to interpret the provenance from seismic profiles. During the early Paleocene, proximal sediments dominated the western depression zone of the East China Sea (WDZ), which was isolated by three sags. Integrated from core, well logging, and grain size data, the sediments in the routing system migrated to the prograding delta or alluvial fan. With statistics of the S2S parameters on the early Paleocene strata, sediment supply, average terrain height, and volume of the S2S system are analyzed from a bubble chart, which indicates that the average terrain height had a positive correlation with the S2S volume. For the middle Paleocene, more sediments from the Zhe-Min Caledonian fault belts on the western side distally migrated to the drainage basin and were deposited as tidally dominated deltas, reflecting an increasing reworking process. The statistical results show that the sediment supply was a dominant factor in the S2S system. As the regression proceeded, the S2S system developed in a semiopen bay setting in the late Paleocene and Eocene. A wave-dominated delta existed on the western side of the WDZ, and the eastern side developed subaqueous deltas. Moreover, we note that the sediment supply and average terrain height were important factors in developing the S2S system. • Source-Identified the provenance area transition in the East China Sea Basin. • Classified the source-to-sink(S2S) system into opening-, closed and semi-opening S2S system. • Build the source-to-sink dynamics pattern that responds to different stages of episodic back arc-basin formation. • Explain source-to-sink transfer process insight from quantitative analysis. [ABSTRACT FROM AUTHOR]

• The structure and morphology of FeCoNi-S@NF were tuned by cation etching strategy. • The 3D nanoflower structure of FeCoNi-S@NF enhances the number of active sites. • The FeCoNi-S@NF exhibits high FE FDCA in a wide potential from 1.45 to 1.60 V. • The FeCoNi-S@NF exhibits bifunctionality for highly efficient HMFOR and HER. To achieve clean and sustainable energy development, the thermodynamically favourable electrocatalytic oxidation reaction of biomass derivatives can be combined with electrolysis for hydrogen production. This process simultaneously generates high-value 2,5-furandicarboxylic acid and green energy (i.e., hydrogen). The present thesis focuses on the synthesis of a novel Fe-Co-Ni nanosheet catalyst foam using impregnation methods and one-pot hydrothermal techniques. Subsequently, the 3D nanoflower FeCoNi-S@NF catalysts are subsequently prepared by sulfurizing the FeCoNi-LDH@NF precursors. These catalysts were then employed for electrolytic seawater hydrogen production coupled with the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMFOR). This strategy is expected to address the slow kinetics of the oxygen evolution reaction (OER). The 3D nanoflower structure of the FeCoNi-S@NF catalyst enhances the exposure of catalytically active sites, while sulfur doping further improves the electron transfer ability. At a low reaction potential of 1.45 V vs. RHE, FeCoNi-S@NF exhibited remarkable performance with a 95.68 % conversion rate for 5-hydroxymethylfurfural (HMF), a 94.83 % yield for 2,5-furandicarboxylic acid (FDCA), and a Faraday efficiency of 94.71 %. Furthermore, FeCoNi-S@NF exhibits a remarkable response in terms of hydrogen evolution in seawater. By utilizing HMFOR as the anodic reaction and low-cost seawater as the cathodic electrolyte for the hydrogen evolution reaction (HER), simultaneous biomass upgrading and hydrogen production can be achieved. Incorporating HMFOR into a two-electrode system for the electrolytic seawater hydrogen production process significantly reduces the needed voltage (1.70 V@10 mA cm−2), thereby potentially decreasing the cost of this process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Classify the episodically rifting processes in PRMB according to their rifting rates. • Identified the provenance evolution in the North PRMB during the Eocene-Oligocene. • Quantitative analysis of the dominated factor to the S2S system developed. Pearl River Mouth Basin (PRMB) is a typical episodically rifting basin, and its sediment records exhibit a multistage infilling process. To build the coupling relationship between the spatial variability of tectonic movement and sediment dispersal pattern, we character the source-to-sink system distribution within continental margin and analysis their dominated factors with quantitative statistical methods. First, we identify the faults and calculate the rifting rate by interpreting the two-dimensional (2D) seismic data and zircon or apatite fission-track data (ZFT/AFT). Accordingly, based on the various trending of the rifting rate evolution, we classified rifting process episodically into three patterns: accelerated rifting decelerated rifting, and uniform rifting. Then, we integrated the data available on detrital zircon U–Pb, rare earth element, and heavy mineral assemblage to identify the responding S2S components associated with the above various rifting processes. Results show that in the first tectonic stage during the early Eocene, the sediments were mainly sourced from an intrabasin provenance area, whereas in the late Eocene to the Oligocene, the paleo-Pearl River provided the sediments to the sink area. We restore the facies association of the sink area by studying the core samples, electric well logs, and three-dimensional (3D) seismic data. During the accelerated and uniform rifting processes, coarse-grained deposited along the boundary faults, which includes the fan delta and subaqueous fans. During decelerated rifting, the depositional environment was dominated by braided channels, meandering channels, and tide-influenced channel accretion. Based on the quantitative analysis the relationship between the grain size of the sediment in each S2S segment and the rifting rate, more fine-grained components were preserved in the decelerated rifting system, while coarse-grained sediments fill the accelerated rifting depression and uniform rifting components. Furthermore, the sediment supply and relative height can influence the volume of the S2S system in the uniform rifting system. In the decelerated rifting basin, the sediment supply is the major factor associated with the development of S2S, whereas the relative height is the major factor associated with the accelerated rifting basin. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) and polystyrene nanoplastic (PSNP) are typical carbonaceous nanomaterials which likely co-exist in soil and sediment. Here, we describe the transport of GO, irradiation reduced GO (RGO) and PSNP in saturated quartz sand both in single and binary systems. In the single transport system, the materials exhibited mobility in the order of GO > RGO > PSNP, due to increased hydrophobicity and decreased negative surface charges. Nevertheless, the co-transport of (R)GO and PSNP in the binary transport system was much more intricate. In Na+ saturated porous media, PSNP preferred to interact with (R)GO relative to the highly negatively charged quartz sand, thus (R)GO carried PSNP to break through the sand column. However, in Ca2+ saturated porous media, the transport of both (R)GO and PSNP was depressed, attributed to the particle-collector and particle-particle bridging effects between Ca2+ and the metal-complexing moieties of the nanoparticles and sand grains. Moreover, GO influenced the co-transport of PSNP to a larger extent than RGO, especially at relatively high ionic strength, because of the more abundant surface O-functional groups on GO providing more complexion sites with Ca2+. These results demonstrated that the transport of negatively charged nanomaterials was greatly related to the hydrophobicity and surface O-functional groups. ga1 • The materials mobility followed the order of GO > RGO > PSNP, which obeyed EDLVO theory. • Highly mobile (R)GO facilitated the transport of PSNP in NaCl solutions. • PSNP decreased (R)GO mobility via narrowing pore throats and providing additional retention sites. • Inhibitory transport of (R)GO and PSNP occurred in CaCl 2 solutions due to cation bridging. • GO and RGO impacted PSNP mobility to varying degrees due to different O-functional groups contents. [ABSTRACT FROM AUTHOR]

[Display omitted] • NiFe-LDH were grown vertically on the surface of BTO which provided more active sites. • t-BTO@NiFe-LDH has excellent OER property due to the self-polarized ferroelectric t-BTO. • Interface tension between BTO and NiFe-LDH made BTO easily self-polarize, causing band tilting. • The superior OER activity results from the active sites and the optimized d-band center. • The design of a ferroelectric OER electrocatalyst based on self-polarization is provided. A flower-like core–shell heterostructured oxygen evolution reaction (OER) electrocatalyst based on tetragonal BaTiO 3 nanoparticles (t-BTO NPs) and NiFe-layered double hydroxide (NiFe-LDH) nanoarrays was prepared in this study. The influence from the self-polarization effect of t-BTO on the OER performance of NiFe-LDH is reported. Intriguingly, the OER activity of the t-BTO@NiFe-LDH heterojunctions in an alkaline media (1.0 M KOH) exhibited a low overpotential of 186 mV at 10 mA/cm2 and a low Tafel slope of 38.3 mV dec-1, which were far superior to those of the component materials: NiFe-LDH (267 mV and 94.8 mV dec-1) and t-BTO NPs (517 mV and 132.4 mV dec-1). Density functional theory (DFT) calculations revealed that the effective electronic modulation between t-BTO NPs and NiFe-LDH nanoplatelets narrowed the bandgap, promoted the electric conductivity, moderately raised Ed (i.e., energy level of the d-band center), optimized the adsorption ability of the oxygen-containing intermediates (*O, *OH, and *OOH), and induced an apparent reduction in the free energy barrier for the transformation from O* to OOH* in the t-BTO@NiFe-LDH heterojunctions. The PDOS result confirmed that t-BTO in the heterojunctions was easier to polarize, which can cause the rapid electron transfer in the OER process. In these heterostructures, the interface tension between BTO NPs and NiFe-LDH endowed BTO with easier self-polarization, thus leading to greater band tilting and faster electron transfer. Multiple synergistic effects of the flower-like core–shell t-BTO@NiFe-LDH heterojunctions enabled them with higher electrocatalytic activity. This work provides an in-depth understanding of the rational design of a high-efficiency, noble metal-free ferroelectric OER electrocatalyst based on the self-polarization of t-BTO NPs. [ABSTRACT FROM AUTHOR]

[Display omitted] • A full-spectrum available photothermal S-scheme heterojunction is prepared. • Synergy of defects and IEF improves charge transport and separation efficiency. • The inverse opal structure with slow-light effect enhances light-capturing ability. • IO-B-TiO 2 /In 2 O 3 performs superior CO yield of 251.25 μmol·g−1·h−1. • DFT and experiments explored the reaction mechanism and S-scheme structure. The conversion of greenhouse gases such as carbon dioxide (CO 2) into fuel and high-value chemical materials using solar energy is considered as a viable solution to the environmental pollution and the alleviation of the energy crisis. Herein, a black titanium dioxide/indium oxide S-scheme heterojunction (IO-B-TiO 2 /In 2 O 3) with a three-dimensional porous inverse opal structure was prepared. In the photocatalytic reduction of CO 2 , IO-B-TiO 2 /In 2 O 3 exhibited an excellent CO production rate (251.25 μmol·g−1·h−1), being 8.62 and 1.55 times of pure IO-TiO 2 and IO-B-TiO 2 /In 2 O 3 under non-photothermal conditions, respectively. A series of characterizations and theoretical calculations (DFT) systematically demonstrated that the excellent photocatalytic performance results from the full spectral response of the material, fast charge separation and transport efficiency, and superior photothermal conversion efficiency of the infrared light. This work will provide a promising insight to the design of S-scheme catalysts with outstanding photocatalytic performance via photothermal assistance and the improved solar energy conversion efficiency. [ABSTRACT FROM AUTHOR]

Developed on the North China Craton, the intracratonic Ordos Basin contains a complete Paleozoic-to-Cenozoic sediment record, allowing for long-term paleoenvironmental and climate change investigation. During the Carboniferous–Permian period, convergence between the North China block and the paleo-Yangtze plate to the south resulted in a general marine regression characterized by a series of second-order transgression/regression cycles diachronous along the eastern margin of the Ordos. However, the detailed mechanisms that induced these cycles, as well as the associated paleoecological changes, remain unknown. In this study, we integrate multiple indices, including δ18O and δ13C, rare earth element (REE), paleontological assemblages, and clay content (w (chlorite + kaolinite)/ w ((Illite) ratio) planar distribution, to restore the paleo-water depth distribution. These parameters are then used to reconstruct the paleo-sea level from the Pennsylvanian to the middle Permian. We conclude that the direction of second-order transgression/regression was mainly toward the east during the Pennsylvanian–early Permian and switched clockwise toward the north during the middle Permian. We suggest that the second-order cycles, diachronous in space and time, are mainly linked to local variations in sediment supply and regional uplift. Using detrital zircon U–Pb data and the REE and trace element content and heavy mineral assemblages (HMA), we estimate the sediment provenance area. The sediment volumes deposited in the basin through time are obtained using 2D seismic data. During the Carboniferous, the coarse-grained sediments deposited in the eastern Ordos were derived from the uplifting Helan Mountain (Qiandam–Qilian orogenic belt). By the middle Permian, the detrital material became multi-sourced, thus issuing the Yinshan range to the north and the Qinling range to the south. We then integrate the description of numerous core samples with electric log and 2D seismic data to reconstruct the sediment facies associations across the first-order regression from the Carboniferous tidal flat depositional system to the middle Permian prograding fluvial delta system. According to the transfer of the glacial epoch, the sedimentation rate, and the transgression/regression rate above, we classify the evolution process into three patterns: low-transgression rate and less-sediment supply pattern (the late Carboniferous), high regression rate and mass sediment supply pattern (the north block during the early Permian), and low regression rate and mass sediment supply pattern (the south block during the Sakmarian stage). Lastly, with the quantitative calculation of the source-to-sink (S2S) parameters, including the S2S system volume and the elevated height of regional uplift with the 2D seismic data, we propose the mechanism of transgression/regression in the Ordos Basin, responding to the above three pattern s. The first pattern was controlled by regional uplift, whereas the second pattern was controlled by sediment supply. As to the third one, uplift and sediment supply could affect the transgression/regression process. • Identified provenance area of the eastern margin of the Ordos Basin during the Pennsylvanian to the early Permian. • Reconstructed the clockwise evolution process of the relative sea level in the study area. • Identified different types of source-to-sink systems insight from the sea level and sediment supply. • Proposed an integrated method to determine the dominating factors influencing the relative sea level. [ABSTRACT FROM AUTHOR]

The extensive application of antibiotics in livestock industry inescapably leads to their release to the aquatic environment. The occurrence of multiple engineered nanomaterials (ENMs) in various water systems also has been widely observed. The interaction between the coexisting antibiotics and ENMs will affect their transport and fate in water. In this study, the adsorption of two representative veterinary antibiotics—tylosin (TYL) and sulfamethazine (SMT) by binary nano-adsorbents—carbon nanotubes (CNTs) and titanium dioxide nanoparticles (nTiO 2) was investigated. Results exhibited that the adsorption behavior and mechanisms of TYL/SMT by the binary nano-adsorbents were highly pH-dependent. Under near-neutral condition (pH unadjusted), nTiO 2 inhibited the adsorption of TYL/SMT by CNTs, mainly because of adsorption sites competition, weaker EDA interaction and less negatively charged CNT-nTiO 2 clusters formation. Under acidic condition (pH 5.0), nTiO 2 heteroaggregated with the oppositely charged CNTs via electrostatic attraction and generated large agglomerates, thus significantly decreased the possible adsorption sites of the adsorbents. Under alkaline condition (pH 8.0), nTiO 2 inhibited the adsorption of TYL, but slightly promoted the adsorption of SMT, which resulted from the weaker electrostatic repulsion between the anionic SMT− and the less negatively charged nTiO 2. The adsorption behavior and mechanisms were also confirmed by the dynamic light scattering (DLS) and electrophoretic mobility (EPM) measurement, the transmission electron microscopy (TEM) images and the Derjaguin–Landau–Verwey–Overbeek (DLVO) calculation. The observations of this study highlighted the mechanisms controlling the adsorption affinity between antibiotics and binary nano-adsorbents, and also opened up new horizons for the interaction and fate of nanomaterials and organic contaminants in the aquatic environment. [ABSTRACT FROM AUTHOR]

Sedimentary features of a source-to-sink (S2S) system produce distinct responses to diverse bedrock types (i.e., silicate and carbonate rocks) in the catchment; these majorly influence the sediment flux, volume, and grain size in the sink area. By comparing a modern S2S system of Holocene Erhai Lake Basin (ELB) (in southwestern China) and an ancient S2S of Eocene western Offshore Bohai Bay Basin (OBBB) (in eastern China), we investigated the differences and proportional ranges among sandy sediment flux (Q f) and sediment discharge (Q s) from catchment associated with diverse bedrock types in a humid and subtropical lacustrine rift basin by combining with the Google-topographic-map, BQART-model, and seismic-geomorphology analysis. Based on geomorphological and 3D visualization analysis, we identified the differences among multiscale catchment-fluvial segments and their sedimentary responses in S2S systems, and then extracted parameters of catchment-unit area (A), catchment relief (R), and total sediment discharge (Q s , calculated by BQART model). Furthermore, we analyzed sediment-dispersal patterns and sandy sediment fluxes in the nearshore (Q f) using regional geologic data, outcrops and the Google Earth database in the Holocene ELB, and using seismic geomorphology in the Eocene western OBBB. Finally, quantitative analysis of the modern and ancient S2S segments was used to investigate the total sandy sediment flux (Q f), which is supplied by >60% of the entire sediment discharge (Q s) for catchments with silicate bedrocks (e.g., metamorphic rock and granite), while the ratio Q f /Q s corresponding to carbonate bedrocks is less than 30%. Additionally, the ratio Q f /Q s for catchments with mixed silicate carbonate bedrocks ranges between 30% and 60%. These results not only provide a new perspective for investigating sandy sediments in a subtropical lacustrine rift basin, but also yield implications for better understanding of continental S2S system theory for diverse bedrock types. • Divide the modern and ancient source-to-sink (S2S) segments into multi-order catchment units and fan-lobes. • Extract the kernel parameters of sediment discharge from catchments and sediment flux of proximal fans. • Discuss the proportional range between sandy sediment flux and sediment discharge associated with diverse bedrock types. • Establish a flux model of source-to-sink segments with diverse bedrock types in subtropical lacustrine rift basins. [ABSTRACT FROM AUTHOR]

During the Eocene, the western Shaleitian Uplift and its adjacent sags constituted a source-to-sink (S2S) system on an active lacustrine basin margin with a steeply dipping boundary fault. We integrated a range of data types with subsurface observations from the western offshore Bohai Bay Basin (OBBB) that allowed us to quantify the size and classification of catchment-fluvial segments, and analyze the sedimentary architecture and sediment fluxes of the proximal fan-delta system. We then discovered quantitative coupling relationships among the parameters of ancient source-to-sink segments. Results show that in the study area the bedrock of the western Shaleitian Uplift is composed of Proterozoic migmatized granites or granites. On the basis of paleogeomorphology reconstruction, we established classification standards for multi-scale catchment units, divided the provenance into four third-order catchment units, obtained quantitative parameters of the catchment-unit area (A), catchment relief (R), and total sediment discharge (Q s , calculated by BQART model) and then confirmed the scales and distribution (cross-sectional area, S cs) of sediment-transport pathways. Furthermore, we analyzed tectonic subsidence, sediment-dispersal patterns, and sediment fluxes of fan-delta systems (Q f) using seismic sedimentology in the third member of the Eocene Shahejie Formation (Es 3). Finally, we used quantitative, multivariate, statistical analysis of the parameters involved in the source-to-sink segments to (1) show the proportional range between total sediment fluxes of fan delta (Q f) and sediment discharge (Q s) from catchment (largest rate of Q f /Q s in the lower part of Es 3 , smallest rate of Q f /Q s in the middle part of Es 3 , and the range from 30% to 70%) and (2) arrange the mainly controlled parameters in terms of their importance (i.e., rate of tectonic subsidence, catchment area, catchment relief, and cross-sectional area of sediment-transport pathway are listed in order of importance). This study can provide an effective way of quantifying and ordering the parameters important in that controlling a complex ancient source-to-sink system, thus helping to achieve an understanding of the process of tectono-sedimentary evolution on a rifted, lacustrine-basin margin. • Divide the catchment segment into different orders and pick up the main parameters. • Indicate the sediment-dispersal patterns and sediment flux of fan-deltas in an active extensional setting. • Reveal the correlation and ordering of multiple important parameters of ancient source-to-sink in a rift basin margin. [ABSTRACT FROM AUTHOR]

The East China Sea Shelf has an unusually wide and low gradient shelf, supplied from sediment‐charged rivers and large river delta systems, with bottom currents sweeping the sea floor and located in the path of strong typhoons. Sediment gravity flow deposits, including four hybrid event beds and a high density turbidite, are identified in a core from the mid‐shelf of the East China Sea. The hybrid event beds typically comprise three or two internal divisions from the base to the top: (i) H1, H3 and H5; or (ii) H3 and H5. Radiocarbon ages of the hybrid event beds were in the range of 3821 to 8526 yr bp. Based on correlation with surrounding cores, the hybrid events may have happened at any time between 1930 yr bp and 3890 yr bp. The δ13C values in hybrid event beds together with bathymetry data suggest local erosion on the shelf. The average δ13C value for the H1 division is similar to the H3 division in the hybrid event beds, implying that the organic matter in the H1 and H3 divisions may come from the same source area. Cross‐plots of upper continental crust normalized rare earth elements in the five units reveal that the sediment source of the four hybrid event beds and the turbidite was ultimately primarily from Korean rivers. Partial transformation from a moderate‐strength debris flow with the additional role of erosional bulking can explain occurrences of hybrid event beds on the East China Sea Shelf. The data indicate that hybrid sediment gravity flow deposits were sourced from intra‐shelf failures and subsequently transformed and deposited as hybrid event beds. The study shows that hybrid sediment gravity flows and turbidity currents may not necessarily indicate proximity to a major fluvial or deltaic system and that intra‐shelf sedimentation can be a sediment source. It is unlikely that the debris flows and turbidity currents were triggered by a hyperpycnal flow or tsunami, because both can carry continental and/or coastal signals which have not been recognized in the core. Typhoons are the probable triggering mechanism. [ABSTRACT FROM AUTHOR]

In multi-phase rift basins, the links between fault activities and sequence stratigraphic architectures are still poorly understood compared to single-rift basins. The purpose of this work is to give implications for tectono-stratigraphic signatures in multiphase rifts based on seismic data from the Zhu-3 Depression in the Pearl River Mouth Basin, China. Stratigraphically, three composite sequences (CS1-3) defined by major unconformities in the Paleogene successions of the Zhu-3 Depression are interpreted, with each one subdivided into two or three third-order sequences. Regional unconformities and basin configurations indicate two episodic rift phases, termed rift phase 1 (formed CS1), and rift phase 2 (formed CS2) followed by a lithospheric breakup phase (formed CS3). From rift phase 1 to rift phase 2, the basin evolved from small-sized, independent half-grabens into relatively large-scale grabens and finally a dish-like basin configuration. Fault displacement and stratigraphic stacking patterns revealed three distinctive structural stages of rift phase 1: rift initiation (WC-SQ1), rift development (WC-SQ2), and rift termination (WC-SQ3) stages. However, an immediate decrease in fault activity was recorded in the rift phase 2. Immediate strain localization under rotated extension fields during episodic rift phases led to variabilities in tectono-stratigraphic architectures. In turn, this transition may likely contribute to interpreting the depositional pattern from balanced infill during rift phase 1 to an overfilled pattern during rift phase 2 as well as the breakup stage in response to possible enhanced sediment supply. This work enhanced our understanding of additional hydrocarbon evaluations in the Zhu-3 Depression, South China Sea. • The Eocene-Oligocene sequence framework in the Zhu-3 rift are systematically reported. • Fault pattern, basin geometry and drainages basin in episodic rift phases are illustrated. • Tectono-stratigraphic signatures of three rift cycles in the Zhu-3 rift are proposed. • Controls of boundary fault arrays evolution on two-phase rift development are discussed. [ABSTRACT FROM AUTHOR]

Abstract Mitigation of space debris draws much concern today since its steadily increasing number and the consequent increased risk of space activities. Among all the active debris removal strategies, tethered space-tug is considered as a promising method due to its safeness of capture and dynamic stability of pull strategy. Although promising, challenges remain in its position and attitude control especially when the target is tumbling, which may cause damage to the appendages or result in collisions. This paper addresses the problem of position and attitude control of a tethered space-tug system with only tether tension available for the target. Based on Takagi-Sugeno fuzzy technology, a guaranteed cost guidance and control law is obtained by solving a set of linear matrix inequalities. The effectiveness of the guidance and control strategy is validated by numerical simulations. [ABSTRACT FROM AUTHOR]

This paper deals with the problem of mixed H∞ and passive control for flexible spacecrafts subject to nonuniform sampling and time-varying delay in the input channel. An impulsive observer-based controller is introduced and the resulting closed-loop system is a hybrid system consisting of a continuous time-delay subsystem and an impulsive differential subsystem. As a first result, we derive a generalized bounded real lemma (GBRL), that is, a generalized H∞ performance criterion, for the impulsive differential subsystem by constructing a time-varying Lyapunov functional. Then, on the basis of this GBRL and utilizing the Lyapunov–Krasovskii approach, a sufficient condition is derived to asymptotically stabilize the closed-loop system and simultaneously guarantee a prescribed mixed H∞ and passivity performance index. A design method is proposed for the desired controller, which can be readily constructed by solving a convex optimization problem with linear matrix inequalities (LMIs) constraints. Finally, numerical experiments are provided to support the theoretical results, and comparisons with former approaches are also discussed. [ABSTRACT FROM AUTHOR]

This paper presents the current body of knowledge regarding the evolution of a braided–meandering system in the southern Junggar Basin, north‐west China, based on the preserved architecture evidences. The response to climate change was also discussed. Herein, 10 types of lithofacies are summarized, including information of their primary sedimentary structures, characteristic lithology, and geometry. This study focuses on recognizing the architectural elements within the channels (migrating channel: CHm, switching channel: CHs, transiting channel: CHt, and filling channel: CHf), the bar units (downstream accretion: DA, lateral accretion: LA, unit bar: UB, and compound bar: CB), and fine‐grained clastic deposits (floodplain fines: FF and overbank fines: OF). Three representative sections of outcrops were selected, and detailed observation and analysis of these sections revealed 3 stages can be divided: the braided stage, in which the deposits show an evidence of CHm, DA elements which are the mainly architectural elements, multichannel with aggradational filling; The transformation between braided–meandering stage, during which the fluvial system consists of CHt and CHm elements with lateral accretion; and meandering stage which is characterized by dominance of CHm, LA elements, and the channels become isolated and meandering. Finally, this paper concludes with an interpretation of climate events as manifested by the fluvial archives of the colours of sedimentary rocks, special mineral, palaeontology, geochemistry spanning the Middle–Upper Jurassic (between 166.1 and 152.1 Ma). [ABSTRACT FROM AUTHOR]

This paper considers the robust stability and stabilisation of uncertain impulsive positive systems with delay in state. The robust global exponential stability criterion under ranged dwell-time is first established by employing an impulse-time-dependent copositive Lyapunov function. Extensions to the exponential stability of the considered system under constant, arbitrary, maximal and minimal dwell-time are then derived. To positively stabilise the considered system under ranged dwell-time, a method of state-feedback controller design is presented based on the derived stability condition. Several numerical examples illustrate the reduced conservatism and effectiveness of the obtained theoretical results. [ABSTRACT FROM AUTHOR]

Attribute weight assignment plays a key role in multiple attribute decision making (MADM). For the issue of labeled multiple attribute decision making (LMADM), the existing methods of attribute weight determination that have been well developed for MADM usually ignore or do not take full advantage of the supervisory function of labels. As a result, the weights produced by these methods may not be ideal in practice. To make up for this deficiency, this paper develops an objective method based on Bayes risk. Specifically, the LMADM problem is first put forward, then a Gaussian kernel based loss function is proposed to cope with the drawback that the loss function in Bayes risk is usually determined by experts. Meanwhile, Mahalanobis distance and fuzzy neighborhood relationship are employed to measure the fuzziness of data set. Finally, a number of experiments, including the comparison experiments on UCI data and the effectiveness evaluation of fighter, are carried out to illustrate the superiority and applicability of the proposed method. [ABSTRACT FROM AUTHOR]

This paper investigates the trajectory planning and control of autonomous spacecraft proximity operations with impulsive dynamics. A new integrated guidance and control scheme is developed to perform automated close-range rendezvous for underactuated microsatellites. To efficiently prevent collision, a modified RRT* trajectory planning algorithm is proposed under this context. Several engineering constraints such as collision avoidance, plume impingement, field of view and control feasibility are considered simultaneously. Then, the feedback controller that employs a turn-burn-turn strategy with a combined impulsive orbital control and finite-time attitude control is designed to ensure the implementation of planned trajectory. Finally, the performance of trajectory planner and controller are evaluated through numerical tests. Simulation results indicate the real-time implementability of the proposed integrated guidance and control scheme with position control error less than 0.5 m and velocity control error less than 0.05 m/s. Consequently, the proposed scheme offers the potential for wide applications, such as on-orbit maintenance, space surveillance and debris removal. [ABSTRACT FROM AUTHOR]

Rough set theory has been playing a significant role in data mining, but deficiencies still exist in fast attribute reduction and self-learning for decision systems. Grid-clustered rough set (GCRS) model computing the universe partition based on grid subspace cluster (GSC) algorithm is constructed in this paper to fill the aforementioned gaps. GSC algorithm characterized by densities and distances in grid subspace is firstly presented along with the automatically selecting of cluster centers. Then a rough self-learning theory including extensional learning and intensional learning is raised. To realize quick attribute reduction and self-learning, a novel rough set model named GCRS that integrates rough set theory and GSC algorithm is proposed, and a corresponding quick attribute reduction algorithm and a rough self-learning algorithm based on GCRS are subsequently designed. A multitude of experiments demonstrate three aspects: a) results of attribute reduction using GCRS model are proved to be of higher classification accuracies; b) attribute reduction based on GCRS model for big data manifests faster speed; c) results of rough self-learning experiments illustrate the validity of the proposed theory. [ABSTRACT FROM AUTHOR]

The bottom-up construction of highly functional metallamacrocycles from simple building blocks is a challenge of much current interest. We have used solvothermal reactions of a bifunctional p-bitmb ligand with [Ru(arene)X2]2 in CH2Cl2 or CH2Br2 to generate the novel mononuclear metallamacrocyclic [RuX(arene)L2CH2]X3 complexes 1–3 (1, arene = p-cym, X = Cl; 2, arene = bip, X = Cl; 3, arene = p-cym, X = Br), which were characterized by various techniques. These complexes are “bowl-like” and have two faces: one coordinative Ru centre (arene)Ru(N,N)X bridged by L (L = 1,4-bis(imidazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene, p-bitmb) to a dipositive bis-imidazolinium centre. Cl− or Br− anions can be trapped inside the cavity of the “bowl-like” structure, forming H-bonds with the backbone. Experimental (NMR and ESI-MS) and computational (DFT calculations) studies show that the source of the bridging –CH2– group is the dihalogenated solvent (CH2Cl2 or CH2Br2) that links the two arms of an initially formed non-cyclic complex (arene)RuX2L2 by a mechanism of nucleophilic substitution. Optimization of the reaction conditions afforded the macrocyclic complexes in almost quantitative yields. The applications of these complexes as anti-proliferative agents towards cancer cells and for selective anion sensing have been explored. [ABSTRACT FROM AUTHOR]

The Baxian depression is a typical half-graben located in the Jizhong sub-basin, north China. Commercial petroleum traps have been discovered in the Jizhong sub-basin. However, the 3rd and 4th members of the Shahejie Formation in this sub-basin have been poorly explored. These two members, belonging to the Lower Paleogene age, are buried deeply in the depression. Favorable petroleum reservoir conditions exist in such deep intervals of the half-graben due to the presence of different types and extent of deltas and turbidity fans in various areas. In fact, three types of turbidite fans are developed in the sag below the transitional belt on the eastern gentle slope. This work summarized three stratigraphic trap belts, i.e., the steep slope, gentle slope, and sag. On the steep slope, structural-stratigraphic traps with small-scale delta fronts and turbidite sandbodies are well developed. On the gentle slope, hydrocarbons generally accumulate in the large-scale delta front, onlapping beds and those sandbodies adjacent to unconformities. In the sag, petroleum trap models are typically characterized by pinched-out turbidite sandbodies. Stratigraphic traps were easily formed in turbidite fans below the eastern transitional belt. The petroleum traps that have already been discovered or predicted in the study area indicate that stratigraphic traps have favorable petroleum exploration potential in deeply buried areas (depth >5000 m) in a half-graben basin or depression. [ABSTRACT FROM AUTHOR]

This paper investigates the reservoir characteristics of deep-water lacustrine-delta sandstones in the Upper Triassic Yanchang Formation in the western Ordos Basin, north-central China. The Yanchang Formation has previously been interpreted as a shallow-water lacustrine deltaic succession, and this interpretation has been used to guide petroleum exploration activities which have however met with only limited success. The present study integrates thin-section, wireline log, X-ray diffraction and SEM data from wells in the western Ordos Basin to determine the sedimentary and diagenetic characteristics of sandstones in the C6 and C4+5 sub-members of the Yanchang Formation, and to interpret the units' depositional environment. The C6 and C4+5 sub-members in the study area are composed of: mudstones and fine-grained sandstones, which are interpreted as deep-water pro-delta deposits; laterally-extensive sand sheets (outer delta-front deposits); and small-scale distributary channel and mouth bar sandbodies (inner delta-front deposits). The sandstones have reservoir potential but diagenesis has had a range of effects on reservoir quality. Compaction together with cementation by calcite and clay minerals including chlorite and kaolinite may have affected pore throat geometry and permeability adversely. However dissolution of feldspars and calcite cement created secondary porosity. Hydrocarbon accumulations may occur in delta-front channel and mouth bar sandbodies. Core studies show that some sandstone intervals have relatively good reservoir properties with porosity up to 15% and permeability up to 9mD. [ABSTRACT FROM AUTHOR]

In this paper, a guidance algorithm is presented based on successive convexification for the generation of fuel-optimal 6-DOF spacecraft close proximity trajectory subject to multiple path constraints on sensor field-of-view, collision avoidance, and plume impingement. The whole maneuver process is divided into fly-around and docking phases, where the collision avoidance constraints are only considered in the first stage, while the plume impingement restrictions are implemented when the chaser spacecraft lies within the docking corridor. These discrete decisions are embedded into continuous optimization framework by using the scheme of compound state-triggered constraints. Besides, in order to make full use of the control ability of actuator, the translational and rotational dynamics are reformulated with the thruster configuration. The original optimal guidance problem is converted into a series of convex subproblems by the linearization and discretization of nonlinear system dynamics and constraint functions around the reference trajectory, and iteratively solved by convex programming. Particularly, the algorithm is initialized with an imprecise trajectory obtained from pseudospectral method, and the reference states in the subsequent iterations are obtained by the propagation of the system dynamics in each discrete time interval rather than directly inheriting the latest solution. The convergence analysis is presented to prove that the proposed guidance algorithm converges to the stationary point of original problem under mild conditions. Finally, the effectiveness of the algorithm is demonstrated by numerical simulations. [ABSTRACT FROM AUTHOR]

Mudflow gullies are well developed in offshore areas and on the upper deepwater slope. In this paper, we discuss the formation and characteristics of mudflow gullies in a gas field in the Yinggehai Basin along the northwestern South China Sea margin, and address their impacts on sand body distribution, reservoir heterogeneity, and hydrocarbon accumulation. The geological setting and sedimentary characteristics indicate that the sedimentary environment of the study intervals is located in an area between lower shore face and offshore. The gullies are several meters to a few tens of meters wide, and are filled mainly with thick mudstones interbedded with thin siltstones. Gully fills show an overall fining upward depositional trend, and exhibit a high value, low-amplitude linear GR wireline log shape. Mudflow gullies always incise the underlying sand bars or sand sheets, are overlain by offshore shales and are therefore considered to have developed in a transgressive setting. They are of three basic types, i.e., deep-, moderate- and shallow-classes according to the incision depth. The mudflows developed in offshore environment with rapidly varying topography, and deeply cut the underlying sand bars in lower shore face environment. Influenced by diapiric events, plastic mud-rich sediments were apt to slump, yielding the studied gullies. Gullies can converge to generate a lobe at front of them. In particular, during marine transgression, due to the high depositional rate of muddy sediments and tectonic activity, marine transgression offered the most favorable scenario for the development of these gullies. The mudflows also slumped down the slope into the deep water areas of the basin. Because of the incision of mudflow gullies and transgressive wave ravinement from the southeast, the pre-existing sand bars on the lower shore face were reworked by waves and oriented in a NE–SW direction, perpendicular to the east shoreline to Hainan Island. The sand bars were affected by the mudflow gullies and diapir faults, often isolated from each other, resulting in a weak sand connectivity vertically and laterally. The degree of erosion of the sand bodies by mudflows decreases with depth. In addition, diapiric activity not only induces the formation of mudflow, but also causes CO 2 in the deep buried intervals to migrate into gas reservoir attached by faults. The mudflow gullies are important causes of gas reservoir compartmentalization. CO 2 filling process and gully development in the area resulted in more heterogeneity than the areas without them. Therefore, mudflow gullies control not only the reservoir compartments but also the gas content in the reservoir. [ABSTRACT FROM AUTHOR]

Novel polypyrrole–polyoxometalate/reduced graphene oxide ternary nanohybrids (TNHs) are synthesized via a one-pot redox relay strategy. The TNHs exhibit high areal specific capacitance (2.61 mF cm−2), and the fabricated solid device also exhibits good rate capability, excellent flexibility and mechanical stability. [ABSTRACT FROM AUTHOR]

This study presents a hybrid receiving array architecture that combines analog and digital beamforming to offer a solution for the phased-array feed and other multifunction receive-only applications. This architecture is capable of handling multiple beams forming simultaneous and precision beam steering. To further reduce the hardware counts of the online performance monitoring, a calibration method is proposed in which none of the transmitters or the dedicated distribution network are used. The hybrid architecture concept and built-in calibration are validated experimentally via a prototype. The system performance, including the statistical results of the baseband measurement, phase error, and radiation patterns under various array configurations, are illustrated. An effective phase tuning step of 0.1^\circ, as well as a steering resolution at the subdegree level, is achieved, and the measured aperture distribution is in good agreement with that derived from the proposed online calibration. [ABSTRACT FROM PUBLISHER]

Abstract: The South China Sea (SCS) shows favorable conditions for gas hydrate accumulation and exploration prospects. Bottom simulating reflectors (BSRs) are widely distributed in the SCS. Using seismic and sequence stratigraphy, the spatial distribution of BSRs has been determined in three sequences deposited since the Late Miocene. The features of gas hydrate accumulations in northern SCS were systematically analyzed by an integrated analysis of gas source conditions, migration pathways, heat flow values, occurrence characteristics, and depositional conditions (including depositional facies, rates of deposition, sand content, and lithological features) as well as some depositional bodies (structural slopes, slump blocks, and sediment waves). This research shows that particular geological controls are important for the presence of BSRs in the SCS, not so much the basic thermodynamic controls such as temperature, pressure and a gas source. Based on this, a typical depositional accumulation model has been established. This model summarizes the distribution of each depositional system in the continental shelf, continental slope, and continental rise, and also shows the typical elements of gas hydrate accumulations. BSRs appear to commonly occur more in slope-break zones, deep-water gravity flows, and contourites. The gas hydrate-bearing sediments in the Shenhu drilling area mostly contain silt or clay, with a silt content of about 70%. In the continental shelf, BSRs are laterally continuous, and the key to gas hydrate formation and accumulation lies in gas transportation and migration conditions. In the continental slope, a majority of the BSRs are associated with zones of steep and rough relief with long-term alternation of uplift and subsidence. Rapid sediment unloading can provide a favorable sedimentary reservoir for gas hydrates. In the continental rise, BSRs occur in the sediments of submarine fans, turbidity currents. [Copyright &y& Elsevier]

Materials with photochromic properties have great potential for applications such as molecular switches, light-controlled materials, optical patterns, information storage, etc. Therefore, photochromic materials are urgently needed to meet the demand for such practical applications. Herein, a novel photochromic molecule perylene diimide salicyl hydrazide (PDISH) was synthesized, and its photochromic behavior and self-assembly properties were systematically studied. It exhibits reversible photo-controllable colour changes in the solution and solid states due to the excited-state intramolecular proton transfer (ESIPT) effect-coupled charge transfer (CT). Furthermore, the prominent morphological transition of PDISH from nanospheres to micro-rods occurred via self-assembly, rendering the fluorophores useable for monitoring and visualising the aggregation process. And the result of theoretical calculations of PDISH indicates that protons on nitrogen atoms have a significant effect on the fluorescence properties of PDISH. More interestingly, in the presence of Cu2+, the intramolecular hydrogen bonds of the compound were destroyed, resulting in rearrangement of its structure. Therefore, this PDISH has potential applications for Cu2+ detection. This study demonstrates that the PDISH compound is a multifunctional organic luminescent material that exhibits excellent photochromism, self-assembly, and ion probe properties. [Display omitted] • A photochromic salicylhydrazide based on perylene diimide and its application for ion sensor probes. • A salicyl hydrazide-disubstituted perylene diimide PDISH was developed. • Compound exhibit the eye-detectable photochromism and photocontrolled luminescence. • Novel self-assembly morphological transitions from nano-vesicles to micro-rods. • Multifunctional combination of photochromism, self-assembly and ion response. [ABSTRACT FROM AUTHOR]

• A high-performance ORR/OER catalyst is prepared by using corn stalks as precursor. • FeN x and FeC x originated from Fe, N-dual doped improve catalytic performance. • The Fe-MNC catalyst achieves an excellent performance for Zn-air batteries. [Display omitted] The development of affordable and perdurable electrocatalysts for oxygen reduction/evolution reaction (ORR/OER) has been considered as an alternative to address the global energy crisis and grievous environmental pollution. Therefore, exhaustively developing low-cost bifunctional electrocatalysts is of significance especially derived from the ubiquitous carbonous biomass materials. Here, an advanced catalyst of Fe, N-dual doped mesoporous and microporous carbon nanosheets (Fe-MNC) is synthesized by using Fe-pyridine coordination complex as the sources of Fe, N and corn stalk soot as the support. The Fe-MNC possesses vigorous electrocatalytic performance for ORR with an E 1/2 of 0.85 V. Moreover, for OER, the overpotential is as low as 309 mV at the current density (j) of 10 mA cm−2 and the Tafel slope is 127 mV dec−1. What's more, a rechargeable Zn-Air battery is constructed based on Fe-MNC as the air cathode. This work not only establishes an easy access and sustainable way to produce a cost-cutting and highly efficient ORR/OER catalyst, but also paves a new way for a greater value-added utilization of biomass carbon for sustainable energy conversation. [ABSTRACT FROM AUTHOR]

• Tridoped defect-rich porous carbon-based electrocatalyst was synthesized. • Electrocatalyst (GNP-900) featured with high surface area and enormous defect sites. • GNP-900 has excellent trifunctional catalytic performances of HER, OER, and ORR. Electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) are practical mechanisms for sustainable energy conversion and storage. Metal-based electrocatalysts are widely used in the above fields. However, metal-based electrocatalysts have many disadvantages, including resource scarcity, low durability, and damaging environmental effects. To address this dilemma, we investigated a simple pyrolysis mode to synthesize a nitrogen (N), phosphorus (P), and oxygen (O) -doped (i.e., tridoped) defect-rich porous carbon-based electrocatalyst, named as GNP-900, for HER, OER, and ORR by heating the assembled hybrid super molecule of graphene oxide (GO), phytic acid (PA), and polyethyleneimine (PEI) at 900 °C. The developed GNP-900 shows high electrocatalytic activities for HER and OER with low Tafel slopes of 93 mV dec−1 and 127 mV dec−1 and small overpotentials of 179 mV and 299 mV, respectively, to achieve the current density of (j) ± 10 mA cm−2. For ORR, the GNP-900 offers a very small loop current density and presents good CH 3 OH tolerance. In addition, features with a positive onset potential of 0.96 V and half-wave potential (E 1/2) of 0.824 V, strongly suggesting the high electrocatalytic performance. The excellent electrocatalytic performance of the porous GNP-900 is mainly ascribed to the tridoped heteroatoms and the abundant defect sites on the substrate. [ABSTRACT FROM AUTHOR]

In order to control the microstructure of polyaniline (PANI) and enhance the interfacial bonding between PANI and carbon substrate, a vacuum infiltration method is put forward to prepare functionalized carbonized cotton cloth (FCC)@PANI nanocomposite. In which, FCC is soaked in dilute PANI solution under vacuum to achieve the permeation adsorption of PANI. After the solvent evaporated, strawberry-like FCC@PANI nanocomposite is produced with PANI nanoparticles embedding on the fiber surface. This novel method effectively avoids the generation of PANI nanofibers and their agglomeration, even at a high PANI loading of 28.1 wt%. Serving as electrodes in symmetric supercapacitors, the optimum FCC@PANI composite exhibits the maximum capacitance of 350.8 F g−1 (1859.2 mF cm−2) at 1 A g−1, and a high capacitance retention of 90.8% for 10,000 cycles. The performance is much better than that of optimized FCC/PANI composite synthesized by in-situ polymerization, due to the low internal resistance, fast transfer of electrons/ions and a strong interfacial bonding interaction. In view of the easy operation and scalability, vacuum infiltration method has a promising prospect for preparing carbon fabrics/PANI composite electrodes in large scale. Image 1 • Vacuum infiltration method is put forward to prepare FCC@PANI composite. • The novel method enables the composite with a strawberry-like structure. • Strong interfacial bonding is formed between PANI nanoparticles and fiber. • The capacitance retention is 90.8% after cycling for 10,000 cycles at 10 F g−1. [ABSTRACT FROM AUTHOR]

• Corn stalks was used as the precursor of electrocatalyst. • Electrocatalyst (NPCSS) is featured with a few-layer N-doped porous carbon nanosheets. • NPCSS shows outstanding water splitting electrocatalysis. The environmental crisis of the earth's living has led to in-depth research on energy generation and conversion, and electrocatalytic water splitting appeared suitable for sustainable energy cycles and conversion. Here, a N-doped few-layer porous carbon nanosheets catalyst (labeled as NPCSS) with high specific surface area, enormous active sites and high atom ratio of pyridinic/pyrrolic N was obtained by pyrolysis of mixture of corn stalks soot and melamine. Compared with corn stalks soot during pyrolysis without melamine, the NPCSS is featured with more electrochemically active sites and smaller mass transfer resistance, leading to a superior water splitting activity in 1 M KOH solution. NPCSS shows outstanding water splitting performance with small overpotentials of 195 mV and 358 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) at the current density (j) of 10 mA cm−2, respectively. Our method realizes the high value-added utilization of biomass carbon. [ABSTRACT FROM AUTHOR]

Outcrops of the early-mid Pliocene Orinoco Delta succession on the Atlantic-facing Trinidad continental margin demonstrate facies and stratigraphic architecture of a shelf margin developed in a setting of high sediment supply (Orinoco River) and unusually rapid, sediment accumulation/subsidence (averaging >1 km/My). The studied Moruga clastic wedge of the Orinoco margin consists of a series of topset to deepwater clinoforms with channelized sandstones, river- and mixed-process delta front, wave-dominated delta front, shoreface, prodelta-offshore transition-shelf, upper-slope turbidite channels and mass-transport deposits. The succession is sand-prone and generally consists of coarsening- and thickening-upward delta-front lobes with hummocky/swaley and wave-ripple stratified sandstones indicating dominant storm wave reworking of the delta, particularly when the delta lobes had reached outer shelf sites after long shelf transits. The lower parts of distributary channels are well preserved and characterized by cross-bedded to parallel-laminated sandstones with mud clast lags. The upper parts of channel fills were wave reworked during transgressions, creating hummocky/swaley cross-stratified strata. River-dominated and mixed-process (wave and tide) delta-front deposits occur commonly within stacked, coarsening-upward units. The river-dominated delta front deposits exhibit parallel-laminated to current ripple-laminated intervals with normally graded thin beds changing upward to parallel and low-angle cross lamination, but mixed-process delta front deposits also contain wave and bidirectional current ripples as well as discrete intervals of hummocky/swaley cross-stratification. The preservation of the channel-base as well as river- and mixed-process delta-front deposits in the otherwise storm wave-dominated Atlantic-facing setting suggests some sheltering of the coastal morphology, and possibly low-frequency of large storms, but it is more likely that the unusually rapid subsidence (at rates competing well with Icehouse rates of eustatic sea-level change) and burial of deposits may have prevented the fluvial and tidal signals from being completely reworked by the storm waves in the studied outcrop area. This study demonstrates an example of how the interactions of river-, tide- and wave-generated facies impacted stratigraphic architecture of a rapid subsiding shelf margin built by shelf-edge deltas with high sediment supply. [ABSTRACT FROM AUTHOR]