Search

[Display omitted] • We prepared BVO@VO with dual-phase heterostructure. • The heterostructure enables rapid de/insertion of Zn2+ ions. • The Zn2+ diffusion rate in BVO@VO exceeds VO 2 by three orders of magnitude. • The BVO@VO presents a capacity retention of 96% after 2000 cycles at 2.0 A g−1. • The obtained all-solid-state pouch cell shows excellent electrochemical performance. Rechargeable aqueous zinc ion batteries (ZIBs) have emerged as a promising alternative to lithium-ion batteries due to their inherent safety, abundant availability, environmental friendliness and cost-effectiveness. However, the cathodes in ZIBs encounter challenges such as structural instability, low capacity, and sluggish kinetics. In this study, we constructed BiVO 4 @VO 2 (BVO@VO) heterojunction cathode material with bismuth vanadate and vanadium dioxide phases for ZIBs, which demonstrate significant advancements in both aqueous and quasi-solid-state ZIBs. Benefitting from the heterojunction structure, the materials present a high capacity of 262 mAh g−1 at 0.1 A g−1, superb cyclic stability with 96% capacity retention after 1000 cycles at 2 A g−1, and outstanding rate property with a specific capacity of 218 mAh g−1 even at a high rate of 5.0 A g−1. Furthermore, the flexible quasi-solid-state ZIBs incorporating the BVO@VO cathode demonstrate prolonged cyclic life performance with a remarkable specific capacity of 234 mAh g−1 over 100 cycles at a current density of 0.1 A g−1. This study potentially paves the way for the utilization of heterointerface-enhanced zinc ion diffusion for vanadium-based materials in ZIBs, thereby providing a new approach for the design and investigation of high-performance zinc-ion systems. [ABSTRACT FROM AUTHOR]

To obtain thermodynamically stable single-phase high-entropy monoborides (HEMBs), the formation abilities of two-compound monoborides were evaluated in advance by first principles calculations, which were constructed from two cation combinations chosen from 11 transition metals including Ti, V, Nb, Ta, Cr, Mo, W, Mn, Fe, Co, and Ni. And this method was extended to HEMBs on predicting the relative feasibility of synthesis and the tendency of phase segregation from the mean mixing enthalpy (μ local) and the standard deviation (σ local). Results showed that the contribution of entropy to free energy for entropy-stable HEMBs is large, and HEMBs with small σ local are easy to obtain the higher single-phase formation ability. In addition, four HEMBs ceramic with Vickers hardness (41–45 GPa) were synthesized as superhard materials. This work provides a realistic theoretical guidance for the design and performance research of HEMBs, and will effectively promote the application of superhard HEMBs ceramics. [Display omitted] [ABSTRACT FROM AUTHOR]

In this article, the magnetic energy harvester (MEH) based on the current transformer is an innovative method to provide a potential solution for the power supply of sensor networks. Due to the current fluctuation and nonlinearity of the core, the harvester may produce insufficient power at low primary currents, while the core saturates at high primary currents. Aiming at resolving this problem, a novel method is proposed to improve the performance of MEH. In this method, a capacitor and two switches are used to store energy and modulate the core saturation. The performed analyses demonstrate that the proposed method enhances the harvested power under different primary current and load conditions. This is especially more pronounced at low primary currents and loads. It is found that for a low primary current of 2 Arms at 50 Hz, the harvested power increases by 206%. Moreover, applying this method can also reduce the load voltage by controlling the alternating on–off of the switches, thereby protecting the harvester in case of high primary currents. The theoretical calculation, circuit simulation, and experimental results demonstrate the effectiveness of this method. [ABSTRACT FROM AUTHOR]

For the purpose of using coal gasification coarse slag, carbon/ash separation by flotation is necessary. In this work, kerosene and dodecylamine polyoxyethylene ether (AC1202) were combined to create a composite collector known as AK, which was used in flotation experiments. The findings reveal that when the dosage of the AK collector was raised to 14 kg/t, the tailings ash reached as high as 83.76% and the combustible recovery increased by 69.84% to 81.42%, which is almost 28.62% higher than that of kerosene. The characteristics of various collectors, the strength of the adsorption between various collectors and particles, and the variation in particle hydrophobicity after the action of various collectors are used to elucidate the mechanism of the improved flotation effect with composite collectors. A new technique for separating the carbon and ash from coal gasification coarse slag is provided by the use of the AK collector. [ABSTRACT FROM AUTHOR]

Fast and precise object detection for hgigh-resolution aerial images has been a challenging task over the years. Due to the sharp variations in object scale, rotation, and aspect ratio, most existing methods are inefficient and imprecise. In this paper, we propose a different approach polar method. We locate an object by centre-point, direct it by four polar angles, and measure it by polar ratio system. Our polar coordinate-based method, PolarDet, is a faster, simpler, and more accurate one-stage object detector. Also, our detector introduces a sub-pixel centre semantic structure to further improve classifying veracity. PolarDet achieves nearly all state-of-the-art (SOTA) performance in aerial object detection tasks with faster inference speed. In detail, our approach obtains the SOTA results on authoritative remote sensing object detection datasets DOTA, UCAS-AOD, and HRSC2016 with 76.64% mAP (mean average precision), 97.01% mAP, and 90.46% mAP respectively. Most noticeably, our PolarDet gets the best performance and reaches the fastest speed (32fps) at the UCAS-AOD dataset. [ABSTRACT FROM AUTHOR]

A novel structure for a shell-and-tube heat exchanger (STHX) with triple-layer flower baffles consisting of three blades is proposed in this article. This study also compares the performance of three heat exchangers with triple-layer flower baffles, double-layer flower baffles, and segmental baffles. In order to compare the hydrodynamics and heat transfer characteristics of the three heat exchangers, a water–water heat transfer experiment is designed. The experiment is carried out in a counter-current flow pattern with hot water in the shell and cold water in the tube. Based on the experimental data, at the same flow rate, the shell-side heat transfer coefficients of the STHXs with triple-layer flower baffles and double-layer flower baffles are 31.7% and 14.3% higher than those of traditional segmental baffles, respectively. With an increased number of blades, the STHX with triple-layer flower baffles achieves a comprehensive performance that is 23.7% improved over the STHX with double-layer flower baffles. Finally, an experimental correlative formula is fitted for the heat exchanger with flower baffles and an optimal design scheme for shell-side heat transfer enhancement is proposed. [ABSTRACT FROM AUTHOR]

Ultrasound imaging has developed into an indispensable imaging technology in medical diagnosis and treatment applications due to its unique advantages, such as safety, affordability, and convenience. With the development of data information acquisition technology, ultrasound imaging is increasingly susceptible to speckle noise, which leads to defects, such as low resolution, poor contrast, spots, and shadows, which affect the accuracy of physician analysis and diagnosis. To solve this problem, we proposed a frequency division denoising algorithm combining transform domain and spatial domain. First, the ultrasound image was decomposed into a series of sub-modal images using 2D variational mode decomposition (2D-VMD), and adaptively determined 2D-VMD parameter K value based on visual information fidelity (VIF) criterion. Then, an anisotropic diffusion filter was used to denoise low-frequency sub-modal images, and a 3D block matching algorithm (BM3D) was used to reduce noise for high-frequency images with high noise. Finally, each sub-modal image was reconstructed after processing to obtain the denoised ultrasound image. In the comparative experiments of synthetic, simulation, and real images, the performance of this method was quantitatively evaluated. Various results show that the ability of this algorithm in denoising and maintaining structural details is significantly better than that of other algorithms. [ABSTRACT FROM AUTHOR]

A new high-entropy monoboride (Mo 0.2 Ta 0.2 Ni 0.2 Cr 0.2 W 0.2)B ceramic with a WB-type orthogonal structure was designed and synthesised by in-situ reactive hot pressing at 2000 °C and 30 MPa for 1.5 h under an argon atmosphere. The microstructure of the sintered samples was comprehensively characterised, and the formation of a high-entropy monoboride (Mo 0.2 Ta 0.2 Ni 0.2 Cr 0.2 W 0.2)B ceramic was confirmed. Owing to the high density of the dislocations and strengthening metal-boron bonds, the high-entropy (Mo 0.2 Ta 0.2 Ni 0.2 Cr 0.2 W 0.2)B ceramic exhibited a hardness of 48.51 ± 4.07 GPa, which enabled it to be classed as a new superhard material. In addition, the thermal conductivity (2.05 ± 0.10 W/(m·K) at 400 °C) and electric conductivity (132.30 S/cm) were determined. [ABSTRACT FROM AUTHOR]

Non-isothermal melting phenomenon widely exists in phase change process where mixtures are utilized as phase change materials. It is in the mushy zone that phase transition actually occurs during the melting process. Thus, an in-depth understanding of flow and heat transfer in the mushy zone can provide beneficial ways to improve melting technologies. This article focuses on the evolution of mushy zone for low-Prandtl material under Neumann boundary condition. A two-dimensional model composed of liquid zone, mushy zone, and solid zone is established based on the improved enthalpy-porosity method. The pressure and velocity are coupled with SIMPLER algorithm based on the finite volume method with a Fortran code. The results indicate that the temperature on the heating surface is uneven, which are different from the results under Dirac boundary condition. The existence of mushy zone can supply a buffer to the unsteady melting adjacent to the heating surface initially. And the mushy zone experiences expanding stage and shrinking stage. More time is needed for complete melting and the average temperature on the heating surface gets lower under greater melting temperature range. Increasing Ra can result in augmentation of heat transfer in liquid domain and more inclined interface, and the heat transfer is dominated by heat conduction when liquid phase fraction is less than 20%, and thereafter, it is dominated by natural convection. For the same material, increasing heat flux obviously shortens the total melting time. And the mushy zone is reduced for that greater temperature gradient is produced in the mushy area. [ABSTRACT FROM AUTHOR]

Objective. To explore altered regional neuronal activity in patients with nonarteritic anterior ischemic optic neuropathy (NAION) and its correlation with clinical performances using the regional homogeneity (ReHo) method, which is based on resting-state functional magnetic resonance imaging (fMRI). Method. Thirty-one patients with NAION (20 males, 11 females) and 31 age- and sex-matched normal controls (NCs) (20 males, 11 females) were enrolled in the study. All patients underwent ophthalmic examination, including eyesight, intraocular pressure measurement, optimal coherence tomography (OCT), visual field analysis, and fMRI scans. After ReHo was calculated, we investigated group differences in results between the patients and NCs. We analyzed the relationship between ReHo values for different brain regions in patients with NAION and intraocular pressure, visual field analysis, and OCT. A receiver operating characteristic (ROC) curve was used to assess the diagnostic ability of the ReHo method. Results. Compared with NCs, patients with NAION exhibited higher ReHo values in the left middle frontal gyrus, left middle cingulate gyrus, left superior temporal gyrus, and left inferior parietal lobule. Additionally, they exhibited lower ReHo values in the right lingual gyrus, left putamen/lentiform nucleus, and left superior parietal lobule. ReHo values in the left superior parietal lobule were negatively correlated with right retinal nerve fiber layer values (r = − 0.462 , P = 0.01). The area under the ROC curve for each brain region indicated that the ReHo method is a credible means of diagnosing patient with NAION. Conclusion. NAION was primarily associated with dysfunction in the default mode network, which may reflect its underlying neural mechanisms. [ABSTRACT FROM AUTHOR]

Accurate identification and understanding of various metallic minerals are crucial for deciphering geological formations, structures, and ages. Giving their pivotal role as essential natural resources, a microscopic exploration of metallic minerals becomes imperative. Traditional analytical methods, while helpful, exhibit certain limitations. However, terahertz time-domain spectroscopy, distinguished by its high signal-to-noise ratio, expansive frequency band, and low incident wave energy, is a promising complement to conventional techniques in characterizing metallic minerals. This study employs terahertz time-domain spectroscopy to examine samples of Stibnite, Sphalerite, Galena, and Pyrite originating from diverse geological conditions. The vibrations of molecules within these metallic minerals induce discernible changes in the terahertz spectra. Our findings untiate the extensive potential of terahertz time-domain spectroscopy in the characterization of metallic minerals, affirming its considerable practical value in mineral resource exploration. [ABSTRACT FROM AUTHOR]

High-entropy monoborides (HEMBs) are promising materials for use in cutting tools and wear-resistant coatings owing to their super hardness. Because of the scarcity of reports on powder synthesis, extensive application of HEMBs is limited. To address this problem, a molten-salt-assisted strategy for synthesising HEMB powders is proposed herein. High-entropy (V 0.2 Cr 0.2 Mo 0.2 W 0.2 Ni 0.2)B powders with CrB-type orthogonal crystal structures were successfully synthesised at 1500 °C and examined by using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Subsequently, the mechanism of powder synthesis using molten salt and the advantages of powders prepared by employing molten salt for the densification and hardness enhancement of ceramics were comprehensively evaluated. The (V 0.2 Cr 0.2 Mo 0.2 W 0.2 Ni 0.2)B powders were densified by applying spark plasma sintering to study the microstructural evolution of bulk ceramics with a super hardness of 42.19 ± 2.66 GPa. This work has expanded the family of superhard HEMBs and provides a strong support for the further application of HEMBs. • High-entropy (V 0.2 Cr 0.2 Mo 0.2 W 0.2 Ni 0.2)B powder was synthesized assisted by molten salt for the first time. • High-entropy (V 0.2 Cr 0.2 Mo 0.2 W 0.2 Ni 0.2)B ceramic with hardness of 42.19 ± 2.66 GPa was successfully prepared. • The corresponding molten salt assisted mechanism was analyzed thought a reasonable hypothesis. [ABSTRACT FROM AUTHOR]

[Display omitted] • The high-entropy monoboride ceramic coating was successfully prepared for the first time by atmospheric plasma spraying technology. • The novel design concept-typical precipitation reaction was applied to improve the failure of multiphase coatings caused by interface cracks. • The cooperative effect of the two phases is the main reason for the high wear resistance of high-entropy monoboride ceramic coating. Surface wear-resistant coatings are an effective way to protect tools and provide certain desired properties; however, these coatings often fail prematurely owing to their low plastic deformation ability. High-entropy monoboride (VCrMoWNi)B with an super hardness is a promising material for wear resistance. To balance the high hardness and plastic deformation ability of coating, a novel design concept for the plastic phase precipitate reaction was developed based on the crystallization conditions of the different elements of the composite during deposition of the plasma sprayed high-entropy monoboride (VCrMoWNi)B-Ni 2 B (HEMB-Ni 2 B) composite coating. The microstructure evolution, hardness, and wear resistance mechanism of the HEMB-Ni 2 B coating were thoroughly investigated. Because the second phase Ni 2 B is beneficial for producing plastic deformation and absorbing large strain energy, the cooperation effect between the super hardness of HEMB and large plastic deformation ability of Ni 2 B can significantly enhance the wear resistance of the HEMB-Ni 2 B coating. Particularly, a friction coefficient as low as 0.13 for the HEMB-Ni 2 B coating and outstanding wear resistance are achievable. This study paves the way for the design of high-entropy ceramic coatings with excellent mechanical performance. Moreover, it has a high practical application value in the field of wear resistant coatings. [ABSTRACT FROM AUTHOR]

Cofiring sludge with coal based on existing power plants is a promising method to realize harmless recycling treatment for sludge disposal. However, the influences of sludge addition on NOx emission are still controversial. Moreover, the optimal operating strategies for the cocombustion boiler need further investigations. In this study, the influences of sludge blending ratio, moisture content, sludge inlet position, and air-staging parameter on the combustion characteristics and NOx emission behaviors in a 330-MW boiler were analyzed numerically. The results show that with the increase of sludge blending ratio, the flue gas temperature in the primary zone decreases. The overall burnout ratio declines with the addition of sludge due to the higher ash and moisture contents. Although the sludge contains more N than coal, the NOx emissions in the cofiring case are lower than those in the coal-fired case due to the lower temperature and stronger reducing atmosphere in the primary zone. Reducing the moisture in the sludge is beneficial to the combustion within the furnace. Nevertheless, because of the higher temperature and lower CO concentration within the furnace, the NOx concentration at the furnace outlet increases. For wall-fired boilers, feeding the sludge from the lower burners should be avoided considering the potential surge in NOx emission. When the excess air ratio in the primary zone increases from 0.74 to 0.96, the NOx concentration at the furnace outlet rises by 58%. Hence, although relatively lower excess air ratio in the primary zone could bring adverse impacts on the burnout behaviors, air-staging combustion is still necessary when cofiring sludge in the coal-fired boiler. [ABSTRACT FROM AUTHOR]

SAPO-34 molecular sieve was hydrothermally synthesized by using organosilane phenylaminopropyl-trimethoxysilane (PHAPTMS) as a part of silicon source and tetraethylammonium hydroxide as microporous template at 160 °C. The XRD, SEM and N2 adsorption/desorption characterizations revealed the hierarchical SAPO-34 is a nanocrystal assembly of 50 nm particles prepared in the system. The catalyst showed improved stability and unusual selectivity of propylene and butylene in methanol to olefins reaction by introducing the mesoporous structure and changing the surface acid sites distribution. The yield of light olefins in hydrocarbons was up to 86%, the selectivity of C3= and C4= reached more than 40% and 10%. [ABSTRACT FROM AUTHOR]

Geolocation is a fundamental component of route planning and navigation for unmanned vehicles, but GNSS-based geolocation fails under denial-of-service conditions. Cross-view geo-localization (CVGL), which aims to estimate the geographic location of the ground-level camera by matching against enormous geo-tagged aerial (e.g., satellite) images, has received a lot of attention but remains extremely challenging due to the drastic appearance differences across aerial–ground views. In existing methods, global representations of different views are extracted primarily using Siamese-like architectures, but their interactive benefits are seldom taken into account. In this paper, we present a novel approach using cross-view knowledge generative techniques in combination with transformers, namely mutual generative transformer learning (MGTL), for CVGL. Specifically, by taking the initial representations produced by the backbone network, MGTL develops two separate generative sub-modules—one for aerial-aware knowledge generation from ground-view semantics and vice versa—and fully exploits the entirely mutual benefits through the attention mechanism. Moreover, to better capture the co-visual relationships between aerial and ground views, we introduce a cascaded attention masking algorithm to further boost accuracy. Extensive experiments on challenging public benchmarks, i.e., CVACT and CVUSA, demonstrate the effectiveness of the proposed method, which sets new records compared with the existing state-of-the-art models. Our code will be available upon acceptance. [ABSTRACT FROM AUTHOR]

Schematic diagram of two stages of membrane fouling. [Display omitted] • Desalination performance of PV membrane to industrial reverse osmosis concentrate is first reported. • The produced water meets the discharge standard. • Chemical softening pretreatment is necessary to mitigate fouling. • Membrane flux is recovered 98% after chemical washing. Pervaporation (PV), as a cost-efficient concentrating process, has been studied for Zero Liquid Discharge (ZLD) of desalination. Although high water flux and excellent salt rejection have been reported for many PV membranes. The desalination performance, fouling behavior, and cleaning protocol for treating real reverse osmosis concentrate (ROC) generated from industrial plants have never been studied. Meanwhile, understanding the fouling behavior and cleaning method in the treating process is crucial for the development of suitable PV desalination membranes. In this study, we used a lab-made PV membrane to treat industrial ROC with a high chemical oxygen demand (COD) value and high salt concentrations. The results showed that conductivity and COD of the produced water were below 20 μs/cm and 70 mg/L, respectively, which fulfilled the discharge standard. However, the membrane fouling problem was not trivial. To address the fouling issue, a chemical softening method was adopted to remove the calcium salts of the ROC, and a membrane cleaning method was developed to regenerate the water flux. As a result, a long-term water flux of 31.27 kg/m2·h with a flux recovery rate of 98% were realized. This highlights the potential of PV desalination technology for ROC reclamation. [ABSTRACT FROM AUTHOR]

Pervaporation (PV) is a low-energy membrane separation technology widely studied for desalination, water treatment and solvent recovery where heat is applied to vaporize the feed solution and a vacuum is applied at the permeate side to drive the separation of miscible mixtures. The heart of this technology – polyvinyl alcohol (PVA) that is commonly used as the separation layer of polymer membranes is often fabricated over long cross-linking durations, high temperatures or toxic cross-linkers to prevent it from being dissolved in water. Here we overcome these intrinsic material limitations with a photo-crosslinkable polymer, poly(vinyl alcohol)-stilbazol quaternized (PVA-SBQ), commonly deployed in the printing industry, as the dense selective layer of a thin-film composite PV membrane. The separation performances of the resultant PVA-SBQ/nanofiber thin-film composite membranes were optimized as a function of photo-crosslinking conditions where ultra high water fluxes of 122.6 ± 10.8 kg·m−2·h−1 were achieved while desalinating 3.5 wt% NaCl from water at 75 °C and a permeate pressure of 100 Pa. This high PV desalination performance was also maintained during brine (containing 10 and 20 wt% of NaCl) treatment. [Display omitted] • A fast and green preparation method of PV composite desalination membrane was developped. • Nanocellulose was used as a transition layer for pore size control. • The composite membrane show ultra-high water flux of 122.6 ± 10.8 kg·m−2·h−1 with salt rejection>99.9%. • This membrane was suitable for desalinating brine solutions (containing 10 and 20 wt% of NaCl). [ABSTRACT FROM AUTHOR]

Chlorine resistance mechanism diagram of SMA-g-PVA/FS layer. [Display omitted] • 1, 2-diols of PVA were removed to improve chlorine resistance. • Crystallinity of PVA was decreased by grafting reaction. • Grafted PVA was crosslinked by crosslinker compound to increase both chlorine resistance and hydrophilicity. • PV membranes exhibit high desalination property and superior chlorine resistance. Pervaporation (PV) desalination membranes have good anti-fouling properties due to its hydrophilic dense surface structure. However, organic fouling is inevitable in long-term operation. Sodium hypochlorite (NaClO) is commonly used for cleaning organic pollutant, but it may damage polymeric membrane. Thus, designing membrane material with good chlorine resistance is crucial for expanding its lifespan. In this study, polyvinyl alcohol (PVA) was selected to prepare PV membrane in concern of its hydrophilicity and good film forming property. Its chlorine resistance was improved by removing the more active 1,2-diols of PVA by reacting with sodium periodate, grafting with poly (styrene-co-maleic anhydride) to decrease its crystallinity, and crosslinking using a fluorocarbon surfactant (FS). The resulting PV membrane exhibited the highest reported chlorine resistance of 768000 ppm·h among PV and RO membranes with a high-water flux of 44.5 ± 1.5 kg/m2·h and salt rejection of 99.93%. A long-term fouling and cleaning cycle experiment was carried out using 10000 ppm humic acid to mimic organic foulants. The flux was recovered 100% after the NaClO cleaning. Hence, the chlorine-resistant PV membrane had the ability for sustainable desalination application. [ABSTRACT FROM AUTHOR]

The effects of high-energy ball milling (HEBM) on the sintering ability and microstructure of hafnium diboride (HfB 2) ultrahigh-temperature ceramics (UHTCs) were investigated. After HEBM, the average particle size range of the HfB 2 ceramics decreased to 10–20 nm with a slight alteration in the crystal structure. The microscopic grains of the sintered samples were homogeneous and fine in size. WC removed oxide impurities on the surface of the HfB 2 particles by reacting with the oxide impurities, which further improved the sintering ability of the HfB 2 ceramics. The densification mechanism of the HfB 2 ceramics was also investigated, and nearly fully dense HfB 2 (99.1%) was fabricated by reactive spark plasma sintering (R–SPS) at 2100 °C for 35 min under a pressure of 40 MPa. HEBM increased the surface energy of the fine particles, which provided a sufficient driving force to improve the sintering ability and significantly increase the densification of HfB 2. • HfB 2 ceramics with nearly full density (99.1% relative density) has been successfully prepared. • The high energy ball mill slightly causes lattice distortion and improves sintering property. • Study of the mechanism of densification and grain coarsening of HfB 2 during SPS. [ABSTRACT FROM AUTHOR]

Pervaporation membranes have exhibited great potential for desalinating brine solutions. However, the flux recovery after membrane washing and the membrane's resistance to chemical cleaning reagents were barely studied. Our group has reported excellent desalination properties of PVA based pervaporation membranes. Nevertheless, the membranes were damaged during chemical cleaning due to the poor chlorine resistance of PVA. In this study, the more active 1, 2-diol units of PVA were removed by sodium periodate treatment. And then, the modified PVA was crosslinked by FS-3100, a fluorocarbon based crosslinker, to improve its hydrostability and chlorine resistance. The FS-3100 crosslinked composite (PVA-FS/PVDF) showed a water flux of 34 ± 1 kg m−2 h−1 with a NaCl rejection of 99.93% when desalinated a 35000 ppm NaCl solution at 70 °C. Salt rejections were maintained after soaking in 2000 ppm NaClO, acid (pH = 2), and alkali (pH = 12) solutions for 168, 180, and 180 h, respectively. A long term desalination experiment was carried out using Tween 20 and HA as foulants. The water fluxes could be recovered to 100% after chemical washing without losing salt rejections, indicating an excellent long term operation stability of the FS-3100 crosslinked PV membranes. PVA with superior chemical resistance is obtained by crosslinked with fluorocarbon containing chemical. Image 1 • 1, 2-diols of PVA were removed to improve chlorine resistance. • The PVA was further crosslinked by FS-3100. • The crosslined PVA membrane had superior tolerance to acid, alkali, and chlorine. • Membrane flux could be recovered 100% after chemical washing. [ABSTRACT FROM AUTHOR]

Fast and accurate object detection in aerial images remains a challenging task. Usually, to better describe an object, oriented bounding boxes (OBBs) can better fit objects. Due to high background complexity and large object scale variation, single-angle anchor-based two-stage detectors are widely adopted, which offer better accuracy. However, the single-angle prediction has a small error tolerance for objects with a large aspect ratio, and the hyperparameters of the anchor-based network are difficult to adjust, and the number of hyperparameters is extremely large. Furthermore, the two-stage detection inference speed is slow, and it is difficult to achieve real-time detection. In this paper, we propose Dual-Det, a keypoint-based oriented object detector. We firstly propose a dual-angle with a short-side and ratio regression strategy (DASR), which uses the object centre and the length and angles of two diagonals to represent an object. A short side guided (SSG) loss is further added to guide the direction of the diagonal regression box. To improve the detection performance for dense and tiny objects, a lightweight supervised pixel attention learner is finally proposed. The experiment results show that Dual-Det achieves 90.23 % mAP at 46FPS on HRSC2016, 90.83 % mAP at 46FPS on UCAS-AOD and 72.00 % mAP at 0.018 s per image in the inference phase on DOTA. The code will be open source on . [ABSTRACT FROM AUTHOR]

An I2‐promoted strategy has been developed for the synthesis of thiazol‐2(3H)‐one derivatives from 1,3‐diketones with potassium thiocyanate. This [3+2] cyclization reaction involves C−S and C−N bond formation and exhibits good functional group tolerance. A series of thiazol‐2(3H)‐one derivatives are obtained in moderate to good yields. [ABSTRACT FROM AUTHOR]

As a typical ceramic tool, the wear resistance of Al 2 O 3 /SiC w composites is a prominent parameter in engineering applications. Therefore, how to improve its wear resistance has becomes a research emphasis of ceramic tools. In this work, the Al 2 O 3 /SiC w composites with improved wear resistance were prepared by a novel oscillatory pressure-assisted sinter forging (OPSF) process. The composites prepared by OPSF process not only exhibit higher density and significantly improved mechanical properties, but also own lower coefficient of friction than conventional sinter forging and hot oscillatory pressing processes. EBSD results indicated that the OPSF process could improve the texture of (0001) crystal face, low-angle grain boundaries, high-angle grain boundaries with special angles in the Al 2 O 3 matrix and enhance shear deformation at micro-scales, which are multiple contributed to enhanced wear resistance. Therefore, OPSF process is a promising technique to prepare ceramic-based cutting tools with excellent mechanical properties and wear resistance. [ABSTRACT FROM AUTHOR]

We studied the chaotic peculiarities of magnetic-mechanical coupled system of GMA. Based on the working principle of GMA and according to Newton's second law of motion, first piezomagnetic equation, disk spring design theory, and structural dynamics principle of GMA, the present study established a GMA magnetic-mechanical coupled system model. By carrying out data modeling of this coupled system model, the bifurcation chart of the system with the variation of damping factor, excitation force, and exciting frequency parameters as well as the homologous offset oscillogram, phase plane trace chart, and Poincaré diagram was obtained, and the chaotic peculiarities of the system were analyzed. The influence of parametric errors on the coupled system was studied. The analytical results showed that the oscillation equation of the GMA magnetic-mechanical coupled system had nonlinearity and the movement morphology was complicated and diversified. By adjusting the damping factor, exciting frequency, and excitation force parameters of the system, the system could work under the stable interval, which provided theoretical support for the stability design of GMA. [ABSTRACT FROM AUTHOR]

Desertification leads to the extreme fragility of ecosystems and seriously threatens ecosystem functioning in desert areas. The planting of xerophytes, especially leguminous shrubs, is an effective and common means to reverse desertification. Soil microorganisms play a crucial role in nutrient cycling and energy flow in ecosystems. However, the effects of introducing leguminous shrubs on soil microbial diversity and the relevant mechanisms are not clear. Here, we employed the high-throughput absolute quantification 16S rRNA sequencing method to analyze the diversity of soil bacteria in sand-fixing areas of mixed shrublands with three combinations of shrubs, i.e., C. korshinskii × Corethrodendron scoparium (CaKCoS), C. korshinskii × Calligonum mongolicum (CaKCaM), and C. scoparium × C. mongolicum (CoSCaM), in the south of the Mu Us Sandy Land, China. This area suffered from moving dunes 20 years ago, but after introducing these shrubs to fix the dunes, the ecosystem was restored. Additionally, the effects of soil physicochemical properties on soil bacterial composition and diversity were analyzed with redundancy analysis (RDA) and structural equation modeling (SEM). It was found that the Shannon index of soil bacteria in CaKCoS was significantly higher than that in CaKCaM and CoSCaM, and the abundance of the dominant phyla, including Actinobacteria, Proteobacteria, Acidobacteria, Chloroflexi, Planctomycetes, Thaumarchaeota, Armatimonadetes, candidate_division_WPS-1, and Nitrospirae, increased significantly in CaKCoS and CaKCaM compared to that in CoSCaM. RDA showed that the majority of soil properties, such as total nitrogen (TN), available potassium (AK), N:P ratio, soil moisture (SM), and available phosphorus (AP), were important soil environmental factors affecting the abundance of the dominant phyla, and RDA1 and RDA2 accounted for 56.66% and 2.35% of the total variation, respectively. SEM showed that the soil bacterial α-diversity was positively affected by the soil organic carbon (SOC), N:P ratio, and total phosphorus (TP). Moreover, CaKCoS had higher SM, total carbon (TC), total potassium (TK), and AP than CaKCaM and CoSCaM. Collectively, these results highlight a conceptual framework in which the combination of leguminous shrubs can effectively drive soil bacterial diversity by improving soil physicochemical properties and maintaining ecosystem functioning during desertification reversal. [ABSTRACT FROM AUTHOR]

[Display omitted] • The co-firing of coal and municipal sludge with high moisture content was studied. • The more sludge co-fired, the less NO x emission. • There are higher flue gas temperature and NO x emission at lower moisture content. • Co-firing sludge from the medium-upper burner can reduce the layers of burner. • The shrunk-middle type is the optimum scheme of SA distribution. Using the current coal-fired power plant to treat sludge with large annual production is an efficient sludge treatment method. Nevertheless, the majority of the previous studies concentrated on sludge co-firing with low blending ratio and moisture content in utility boiler. Further analysis and discussion are necessary regarding the impact of sludge with high blending ratio and high moisture content on co-firing performance as well as the potential interactions between high moisture content sludge and coal during the co-firing process. The simulation results of the verified computational fluid dynamic (CFD) model can be regarded as numerical experiments. In the present research, CFD was used to analyze the co-firing characteristics of municipal sludge and coal in a 600 MW tangentially fired utility boiler. The impacts of sludge moisture content, blending ratio, blending strategy, and secondary air (SA) distribution on co-combustion characteristics and NO x emissions were investigated, and their potential synergistic effects were assessed. The co-firing of coal and sludge has little impact on the furnace outlet temperature while potentially lowering NO x emissions, provided that the net calorific value of the feeding of the mixture of sludge and coal is kept constant. The reduction of sludge moisture content can significantly improve co-combustion performance, but it also facilitates NO x production. Blending sludge from the position of the medium-upper burners can reduce the number of layers needed to burn the sludge in practical coal-fired boiler. Furthermore, the SA distribution has a major impact on the furnace outlet flue gas temperature and NO x content. The shrunk-middle type is the optimum scheme for SA distribution. This study contributes to a deeper knowledge of the actual co-firing of sludge and coal in the utility boiler and provides a possible theoretical foundation for the widespread, clean, and effective use of sludge. [ABSTRACT FROM AUTHOR]

The study on CO2 gasification behavior helps to promote the clean and efficient utilization of high-alkali fuels. The high-alkali fuels feature high contents of alkali metals, and sometimes they are also rich in alkali earth metals and iron. Though the influences of minerals on gasification characteristics have been extensively studied, few researchers have selected minerals based on the ash composition of high-alkali fuel. Moreover, the complex interactions among minerals could lead to inaccurate conclusions. In this paper, the CO2 gasification behavior of chars originated from one high-alkali biomass and three high-alkali coals was studied. The effects of principal minerals related to the high-alkali fuels, which were determined through the new plasma ashing method and traditional muffle ashing method, were also further evaluated via synthetic coal char. The synthetic coal char was free from any intrinsic minerals. The results indicate that the gasification reactivities of chars from high-alkali fuels are positively associated with the reaction temperature (900–1200 °C). The biomass char possesses the highest gasification reactivity, and three coal char samples are inferior to various degrees. The related chemicals offer their catalytic activities at 1000 °C in the sequence of K/Na-containing chemicals > Fe-containing chemicals > Ca-containing chemicals. The shrinking core model (SCM) and two-dimensional growth of nuclei model (2DGM) were chosen to conduct the kinetic analysis. The reaction constants of chars from different high-alkali fuels agree with their gasification behavior. Generally, the 2DGM is more suitable than SCM to predict the conversion of selected char samples. In most cases, the additions of chemicals increase the reaction constants. When Fe2O3 and CaCO3 are added into synthetic coal char, the SCM is more accurate to describe the gasification behavior at 900 °C, but the addition of Na2SO4 makes the 2DGM a better one. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) devices play an increasingly important role in solving the energy crisis. However, the conversion efficiency of the PV panel is small. Cooling of PV panels using phase change devices is an effective way to improve the working performance of PV panels. A phase change device with a two-level arrangement of metal-organic phase change materials (PCMs) is proposed. The PCM is filled in a metal cavity made of aluminium plates. A numerical model of the melting process of the combined PCMs is established, and the flow and heat transfer characteristics of the melting process are analysed. The results show that the temperature variation curve of the metal cavity wall close to the PV panel can be divided into three main stages according to the temperature increasing rate, i.e., the first rapidly rising stage, the slowly rising stage and the second rapidly rising stage. The temperature distribution inside the metallic cavity is more uniform compared to the temperature distribution inside the organic material cavity, and the flow in the metallic cavity is weaker, and the temperature controlling time shows a unimodal variation with the increase of gallium filling proportion in the studied ranges, and the optimal filling proportion is 56.9%. [Display omitted] • Solve the dimensionless temperature and velocity governing equations simultaneously. • Ambient and melting temperature influences different stage of temperature rising. • The flow in the metallic cavity is weaker than that in the organic cavity. • The temperature controlling ability of 2-stage heat sink is better than 1-stage. [ABSTRACT FROM AUTHOR]

In the paper, machine learning is demonstrated for the diagnostic enhancement of magnetized plasma probes. In the plasma experiment, the magnetic field greatly affects the properties of plasma and the performance of the probe, which limits the range of measurement parameters and reduces the accuracy of probe diagnostic results. Existing probe correction methods based on improved theory and mechanics cannot completely eliminate the influence of magnetic field and often introduce additional errors. In this paper, a novel machine learning method is proposed to improve magnetized plasma probe diagnostic based on existing methods and traditional probe correction theory. The pressure of the plasma, the total voltage of the circuit, and the magnetic induction intensity are used as input parameters, and the electron density obtained from the probe diagnostics are used as output parameters. The paper presents experiments to analyse the original probe results and the probe results revised by magnetic field probe theory through the machine learning algorithm and compare them with the results of theoretical simulations. The experimental results prove that the machine learning model based on revised data has better learning efficiency and prediction results, which can expand the application scope of traditional probe correction theory and predict results closer to the theoretical value. [ABSTRACT FROM AUTHOR]

Benefitting from the synergistic effect of La3+ intercalation and phytic acid encapsulation, LPVO cathode presents high specific capacity, excellent rate performance, and long cycle life. [Display omitted] • La3+ intercalated and phytic acid-coated V 2 O 5 (LPVO) was prepared. • La3+ intercalation enlarge the lattice spacing of the (0 0 1) crystal plane. • The phytic acid improved structural stability and rate performance of LPVO. • LPVO shows excellent electrochemical performance with high capacity retention rate. The vanadium oxide cathode material is widely regarded as a promising candidate for aqueous zinc-ion batteries (AZIBs). However, its low activity, poor cycling stability, and inadequate rate performance have significantly impeded its commercial viability. In this study, we report a composite electrode material of V 2 O 5 modified with La3+ and phytic acid (LPVO) with enhanced electrochemical performance. The La3+ are capable of intercalating into the interlayer of V 2 O 5 , effectively expanding the interlayer spacing for fast Zn2+ transport, and facilitating the exposure of more Zn2+ storage sites with improved capacity. Additionally, the encapsulated phytic acid could serve as a protective layer to prevent the detachment and dissolution of vanadium compounds during cycles, thereby improving the electrochemical stability. Under the current density of 0.1 A g−1, the capacity of LPVO electrode reaches as high as 385 mAh g−1. Even after 2000 charge–discharge cycles, the capacity retention rate remains as high as 75% (at 3 A g−1). Compared to commercial V 2 O 5 , the Zn2+ diffusion rate of the LPVO composite is improved by nearly 1000 times, reaching 5∼7 × 10−10 cm2 s−1. This approach is universally applicable to enhance electrochemical performance of diverse layered electrode materials, aiding the rapid advancement of cathode design for AZIBs. [ABSTRACT FROM AUTHOR]

This study systematically investigated the variable main electrooxidation mechanism of chlorophene (CP) and dichlorophen (DCP) with the change of reaction conditions at Ti 4 O 7 anode operated in batch and reactive electrochemical membrane (REM) modes. Significant degradation of CP and DCP was observed, that is, CP exhibited greater removal efficiency in batch mode at 0.5–3.5 mA cm−2 and REM operation (0.5 mA cm−2) with a permeate flow rate of 0.85 cm min−1 under the same reaction conditions, while DCP exhibited a faster degradation rate with the increase of current density in REM operation. Density functional theory (DFT) simulation and electrochemical performance tests indicated that the electrooxidation efficiency of CP and DCP in batch mode was primarily affected by the mass transfer rates. And the removal efficiency when anodic potentials were less than 1.7 V vs SHE in REM operation was determined by the activation energy for direct electron transfer (DET) reaction, however, the adsorption function of CP and DCP on the Ti 4 O 7 anode became a dominant factor in determining the degradation efficiency with the further increase of anodic potential due to the disappeared activation barrier. In addition, the degradation pathways of CP and DCP were proposed according to intermediate products identification and frontier electron densities (FEDs) calculation, the acute toxicity of CP and DCP were also effectively decreased during both batch and REM operations. [Display omitted] • Evident degradation of CP and DCP was achieved during both batch and REM modes. • Electrooxidation efficiency in batch mode was limited by the mass transfer rates. • DET reaction was the main electrooxidation mechanism at low anodic potential. • Adsorption energy was key factor during REM treatment at higher anodic potential. • REM treatment exhibited more advantages to reduce ecological risks of CP or DCP. [ABSTRACT FROM AUTHOR]

The technology of oxy-fuel co-combustion is beneficial to consume the large amount of ultra-low volatile coal-based solid fuels (UCF). Moreover, the oxy-fuel co-combustion of various UCFs could also promote the development of coal-chemical industry and reduce the carbon emission in power plants. However, the co-gasification behaviors of various coal-based solid fuels blends at initial oxy-fuel co-firing stage are still vague, which need to be further studied. In the present, the co-gasification features of various coal-based solid fuels blends during initial oxy-fuel co-combustion process were investigated by oxy-fuel co-combustion system experimentally. The rise of O 2 concentration could obtain low Brunner−Emmet−Teller surface area and high Barrett-Joyner-Halenda average pore owing to the collapse of internal structures. The nitrogen gases (X–N) yields show a decreasing trend with the UCF proportion raised. The increasing temperature could promote the gas release of sample. The ash droplets observed on the surface of blend were formed by reactions between oxygen and carbon on the sample surface in 3% O 2 /97% CO 2 atmosphere, which are enlarged with temperature significantly. The present research could be beneficial for efficiency utilization of low-rank coal, together with the reduction of NO x emission and realization of carbon neutrality. • The co-gasification features at initial stage of oxy-fuel combustion were examined. • The synergistic effects of blends during co-gasification process were elucidated. • Tiny oxygen concentration results in collapsing of carbon and ash skeletons. • The addition of UCF could lead to the decreases of X–N yields in blends. • Ash droplets observed on the blend surface are enlarged with the T increased. [ABSTRACT FROM AUTHOR]