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Large amounts of xanthate wastewater generated from mineral beneficiation significantly threaten the ecological environment. MOF photocatalysis is considered as a promising method for the removal of xanthate that is environmentally friendly and has high efficiency. However, the defects in MOFs limit their large-scale application due to poor visible light absorption efficiency and stability in water. In this study, a novel composite material composed of g-C 3 N 4 /AgCl/Ti-MOFs was prepared, and the catalytic degradation effect of butyl xanthate solution under different catalyst ratios and reaction conditions was investigated. The results showed that the composite could still maintain excellent catalytic performance (degradation rate of 99.5% within 90 min) under xenon light and low dosage. The characterization results showed that this excellent photocatalytic performance could be attributed to the following three points: 1) The material could absorb up to 670 nm visible light absorption capacity; 2) excellent stability was achieved (86% degradation efficiency after six cycles); and 3) the Schottky junctions formed by Ag0 and other materials in the composite increased the transfer rate of e−/h+. The possible photodegradation mechanism was proposed according to UV–vis DRS and trapping experiments. [ABSTRACT FROM AUTHOR]

This paper first proposes a novel framework for combining deep learning approach and Synthetic Aperture Radar (SAR) technique to evaluate and predict the condition of bridge displacement. The Long short-term memory (LSTM) neural network and the Small Baseline Subsets InSAR (SBAS-InSAR) are used to predict the longitudinal deformation of the bridge. Firstly, the proposed framework based on LSTM is established to obtain the relationship between the longitudinal deformation of the bridge and the influence parameters (such as temperature, temporal baseline, and others). In particular, the residual connection (RC) module is adapted to form the residual long short-term memory (Res-LSTM) neural network to improve prediction accuracy and robustness. A case study in Nanjing is analyzed to verify the performance of the proposed framework. The extracted datasets obtained from Sentienl-1 are divided into the training, validation, and testing dataset, which can satisfy the requirements in the engineering field. The R 2 and MSE of the testing datasets utilizing the proposed model are 93.17% and 15.62. Furthermore, the results indicated that the proposed framework based on Res-LSTM could predict and warn the abnormal structural deformation, extend the lifespan of structures, and minimize structural damage due to excessive deformation. [ABSTRACT FROM AUTHOR]

Graph convolutional networks (GCNs) have been shown to be effective for hyperspectral image (HSI) classification due to their capacity to learn representations of spatial–spectral features. However, the existing GCN-based models heavily rely on predefined receptive fields to capture and aggregate neighbor information for each node, which limits the ability to adaptively selecting the most significant receptive field from graph data. To address the aforementioned problem, in this article, we propose a novel dynamic adaptive sampling GCN (DAS-GCN) algorithm that captures neighbor information through adaptive sampling to allow the receptive field to be dynamically obtained. The basic underlying idea is that the most meaningful receptive field for each target node can be adaptively discovered, and the edge adjacency weights can be adjusted simultaneously after each adaptive sampling operation. Thus, we enable the graph to be dynamically updated and refined. Specifically, the adaptive sampling operation consists of two complementary components; in the first step, the importance of different remote nodes in a large-scale neighborhood is learned, while in the second step, rich underlying spatial–spectral information is extracted from local neighbors and filtered. The proposed model has the ability to learn how to extensively exploit spectral–spatial correlations from both local and remote nodes. Moreover, the proposed DAS-GCN model has a superior ability to leverage node feature information to naturally generalize and efficiently generate node embeddings for unseen data. The experimental results with overall accuracy on four real HSI datasets, i.e., Indian Pines, Pavia university, Houston 2013, and Salinas are 95.63%, 96.40%, 94.70%, and 99.08%, respectively, which clearly demonstrate the advantages of the proposed method compared with other state-of-the-art approaches. [ABSTRACT FROM AUTHOR]

• The Porous acid-leached expanded vermiculite with a hierarchical structure was obtained. • The mesoporous layered structures effectively enhance the dispersion of amines and serve as rapid diffusion channels for CO 2 towards amine capture sites. • A maximum CO 2 adsorption capacity of 3.29 mmol/g was obtained at 75℃. • The distributions of LUMO and HOMO orbitals, along with the corresponding energy values, were computed. Solid amine adsorbents have attracted significant attention due to their low energy consumption, high selectivity, and environmental friendliness, positioning them as the most promising technology for CO 2 capture. However, current adsorbent carrier materials commonly encounter challenges such as expensive costs and inadequate stability. In this study, acid-activated expanded vermiculite carrier (AEV) with a large pore volume and hierarchical pore structure was prepared. Subsequently, a series of functionalized polyethyleneimine (PEI) adsorbents were synthesized and employed in CO 2 capture experiments to investigate the impact of PEI loading and temperature on adsorption characteristics. The results showed that the acid-modified expanded vermiculite with a large pore volume structure significantly increased amine loading, while the layered structure network promoted amine dispersion. Under the conditions of 50 wt% PEI loading, the CO 2 capture capacity of AEV reached 3.29 mmol/L at 75 ℃. Furthermore, density functional theory was utilized to calculate the adsorption energy and Gibbs free energy change of CO 2 and polyethyleneimine molecules. The HOMO and LUMO distributions of CO 2 molecules with different polyethyleneimine chains were determined using frontier orbital theory , combined with infrared spectroscopy results confirming the conversion of CO 2 into carbamate. Additionally, AEV-PEI50 adsorbent exhibited good stability during 8 cycles of the adsorption process. The obtained results demonstrate that the utilization of layered mesoporous scaffolds offers notable benefits in terms of efficient CO 2 capture. [ABSTRACT FROM AUTHOR]

The hygroscopicity of expanded vermiculite is one of major influence factors for thermal insulating performance. To explore the water absorption properties of expanded vermiculite prepared via electrical heating method, heating temperature effect on the hygroscopicity of expanded vermiculite was investigated under various humidity circumstances. The influencing mechanisms were analyzed by means of Thermogravimetric Analysis-Differential Scanning Calorimeter technique (TG-DSC), Fourier-Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), and the Brunauer–Emmett–Teller technique (BET) for the measurement of the specific surface area. The results of water absorption experiments indicated that the hygroscopicity of vermiculite showed an inversely proportional relationship to heating temperature and the water absorption content of EV-900 was only 6.206 mg/g with a dramatic decline of 91.5% in comparison with that of RV. This decline of water absorption capacity was mainly attributed to the decrease of interlamellar spacing and specific surface area. In addition, environment humidity had a significant effect on water absorption capacity and velocity. The water absorption content of EV-400 sample increased dramatically from 48.414 mg/g at the humidity of 55%–72.929 mg/g at the humidity of 95%, and the equilibrium time reduced from 3 h to 0.5 h. This study will provide a new perspective and theoretical guidance for the development of vermiculite based thermal insulating materials. [ABSTRACT FROM AUTHOR]

Cable-supported bridges are prone to fire hazards, and the corrosion within further compromises their structural integrity. The present study provides a novel framework for assessing fire-corrosion damage of steel wires currently in use. The relations and failure modes of steel wires under coupled effects of fire-corrosion are established by conducting the tensile test utilizing the replaced steel wires after the fire. Experimental studies found that the deterioration tendency of in-service steel wires after the fire is consistent with that of intact ones, while the corrosion level and position of steel wire have a significant impact on its ultimate strain. To predict the residual mechanical properties of cables after the fire-corrosion coupled damage, a comprehensive database of steel wires properties after the fire is established, and then a data-driven surrogate model is proposed. Finally, four grades are suggested to evaluate various damage degrees of in-service cables under corrosion and fire. The findings can provide bridge owners with guidance on how to replace or repair the damaged components after accidents or natural disaster, thereby increasing the reliability and lifespan of bridges and decreasing the costs associated with maintenance, reconstruction, and replacement. • An assessment approach is proposed to evaluate damaged steel wire of in-service bridge under effects of corrosion and fire. • The relations of replaced steel wires under fire-corrosion coupled effects are established by tensile tests. • A surrogate model and database are developed to predict the response of damaged steel wires accurately and rapidly. • Four grades are suggested to assess various damage degrees of in-service cable under coupled effects fire-corrosion. [ABSTRACT FROM AUTHOR]

The thermal insulating performance of expanded vermiculite is closely related to expansibility. A novel method of Mg2+ modification was proposed to improve the vermiculite expansion ratio. The modification process was characterised by energy dispersive X-Ray spectroscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetric-differential scanning calorimeter and scanning electron microscopy. Moreover, the thermal expansion experiment was performed to investigate the expansion behaviours of Raw-V and Mg–V samples at various temperatures. The result indicated that the introduction of Mg2+ could increase the vermiculite interlayer water content through hydration interaction, and the expansion ratio increased 13.7% under the heating temperature of 900 °C after modification. To explain the interaction of magnesium ion and water molecules, a molecular dynamics model was developed, and the simulation results were validated using the binding energy calculation. The results of this study can provide a new perspective and theoretical guidance for the commercial process of vermiculite expansion. [ABSTRACT FROM AUTHOR]

Accurate, cost-efficient and lightweight quantitative detection of steel wire corrosion in cable is an unsolvable issue that puzzles researchers and bridge owners. This paper proposed a portable automatic detection system for quantitative corrosion detection of replaced steel wires. The developed system consists of three parts (an automatic detection device, high-precision infrared imager, and corrosion evaluation algorithm). The proposed method is derived on the basis of Joule's law and the formula for calculating heat release. Then, the corroded specimens with different corrosion degrees and corresponding mass loss ratio were obtained by pre-corroded test to simulate industrial air corrosion and pickling test. The prior knowledge acquisition test utilizing presented automatic detection equipment was conducted to acquire the surface temperature of steel wires with various corrosion ratios by infrared camera after electric heating. Subsequently, the optimal quantitative corrosion prediction model after electric excitation is selected after infrared image processing, outlier filtering, theoretical method comparison, and model modification. Finally, the damaged steel wires from an in-service cable-stayed bridge are chosen to validate the proposed model's generalization ability and predictive accuracy. Furthermore, based on the discovery of characteristics on surface temperature of corroded steel wires after heating, the automatic detection device can be upgraded to realize the quantitative detection of in-situ corrosion of bridge cable. • This study proposed a portable automatic detection system for quantitative corrosion detection of corroded steel wires. • Present a corrosion evaluation approach to characterize corroded steel wire's corrosion ratio. • Develop a predictive model for steel wire corrosion detection utilizing the infrared images of specimens after electrification. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel expanded vermiculite/xonotlite insulation composite was prepared via the hydrothermal method. • Vermiculite thermal expansion and nano xonotlite fiber synthesis were comprehensively studied. • The effect of intercalation on thermal insulating performance was systematically investigated. Natural disasters caused by global warming are threatening the survival of mankind. Reducing carbon emissions is an effective way to prevent global warming. In recent years, the construction industry is playing a dominant role in global energy consumption. Aimed to solve the problem of high energy consumption in the construction industry, a novel expanded vermiculite/xonotlite thermal insulation composite was successfully prepared via the hydrothermal method. The microstructure and thermal performance of the composite were systematically analyzed using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), laser flash analysis (LFA), and infrared thermal imaging. The test results indicated that xonotlite fibers could be inserted well into the interlayers of expanded vermiculite. And the intercalation of xonotlite greatly improved the thermal insulation performance of expanded vermiculite at high temperature. The thermal conductivity of this composite decreased with intercalation rate increasing. The composite with intercalation rate of 51.43 % had the lowest thermal conductivity of 0.2116 W/mK at 800 °C which was 55.36 % lower than the expanded vermiculite sample. Meanwhile, this composite had good thermal stability and high temperature resistance. In addition, the thermal expansion of vermiculite and the synthesis of nano-xonotlite fibers were comprehensively studied and discussed. This study will provide a new perspective and ideas for developing vermiculite-based thermal insulating materials. [ABSTRACT FROM AUTHOR]

An evolutionary modification approach, boron-doped carbon coating, has been used to improve the electrochemical performances of positive electrodes for lithium-ion batteries, and demonstrates apparent and significant modification effects. In this study, the boron-doped carbon coating is firstly adopted and used to decorate the performance of LiFePO 4 . The obtained composite exhibits a unique core-shell structure with an average diameter of 140 nm and a 4 nm thick boron-doped carbon shell that uniformly encapsulates the core. Owing to the boron element which could induce high amount of defects in the carbon, the electronic conductivity of LiFePO 4 is greatly ameliorated. Thus, the boron-doped composite shows superior rate capability and cycle stability than the undoped sample. For instance, the reversible specific capacity of LiFePO 4 @B 0.4 -C can reach 164.1 mAh g −1 at 0.1C, which is approximately 96.5% of the theoretical capacity (170 mAh g −1 ). Even at high rate of 10C, it still shows a high specific capacity of 126.8 mAh g −1 and can be maintained at 124.5 mAh g −1 after 100 cycles with capacity retention ratio of about 98.2%. This outstanding Li-storage property enable the present design strategy to open up the possibility of fabricating the LiFePO 4 @B-C composite for high-performance lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Spinel-type lithium titanate (Li 4 Ti 5 O 12 ) attracts increasing attention for large-scale energy storage as a promising alternative to the graphite in view of superior safety and stability. Nevertheless, the main challenge of Li 4 Ti 5 O 12 anode is the poor electronic conductivity which restricts its battery performance. Herein, the Ce-doped Li 4 Ti 5 O 12 /C embedded in multiwalled carbon nanotube (MWCNTs) network is successfully fabricated through a conventional sol-gel method. The doped Ce 3+ -ion and the formed conductive network between the coated carbon and MWCNTs are favorable to improve the kinetics of Li 4 Ti 5 O 12 toward fast electron transport and Li + -ions diffusion. Such a unique hybrid exhibits superior high-rate and long cycle-life performances when used as an anode material for lithium-ion batteries. It delivers specific capacities of 171.5 and 145.3 mA h g −1 at 0.2 and 10 C between 1.0 and 2.5 V, respectively, and reversible capacity of 129.3 mA h g −1 after 600 cycles at high rate of 20 C with capacity retention of 98.6%. Moreover, the EIS results reveal that this anode material exhibits high electronic conductivity and fast Li + -ions diffusion. This study provides a new stragety to prepare other electrode materials for high-performance energy storage device. [ABSTRACT FROM AUTHOR]

• This study proposed the surrogate model to predict recycled aggregate concrete (RAC) creep behavior utilizing machine learning (ML). • Both grid search algorithm and k-fold cross-validation were utilized to find the optimal hyperparameters. • The XGBoost, was shown to have a higher efficiency and accuracy for predicting RAC creep over other methods. • The results are helpful to comprehend the performance of RAC structures and promote the application of RAC in buildings. This paper comprehensively investigated the surrogate model of recycled aggregate concrete (RAC) creep behavior prediction for the first time utilizing five typical machine learning (ML) algorithms trained with the RAC_Creep_v1 database. The grid search algorithm and k -fold cross-validation are performed to find the optimal hyperparameters. Then, attribute importance analysis and correlation analysis were conducted to evaluate the effect of various input variables on the results. By retraining the XGBoost model after feature selection, the results revealed that loading age has the greatest impact on RAC creep performance. The XGBoost, the optimal model via evaluation and comparison, was shown to have a higher efficiency and accuracy for predicting RAC creep subjected to different variables. Furthermore, the result of this paper can assist designers in comprehending the performance of RAC structures, promoting the application of RAC in buildings and the study for reducing carbon emissions. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel humidity self-regulating interior wall coating composite based on red mud was prepared. • The hygroscopicity of HRCRM were systematically investigated and analyzed. • Various properties of HRCRM were tested and the moisture absorption mechanism was analyzed. Aimed to resolve the problem of excessively high indoor humidity in subtropical areas and develop a new resource disposal technique for red mud, a novel humidity self-regulating interior wall coating composite based on red mud (HRCRM) was successfully prepared using red mud as a matrix material and vermiculite as a humidity regulator. The effects of component proportion, ambient humidity, exposure time on hygroscopicity of this composite were systematically investigated. This composite exhibited good humidity regulating ability with the largest water absorption rate of 16.38% under experimental conditions. Moreover, various properties were tested including surface drying time, hardness, adhesion, coating appearance, water resistance and reusability, meeting the national standard requirements well. The mechanism was comprehensively analyzed by XRD, TG-DTG, FESEM, and FTIR, indicating that the humidity self-adjusting function of HRCRM was realized by regulating the interlayer water storage of vermiculite. This study can provide theoretical and technical guidance for residential environment improvement in subtropical areas and comprehensive utilization of red mud. [ABSTRACT FROM AUTHOR]

• A machine learning framework is developed to predict the cable damage under coupling effects of corrosion and fire. • LS-SVM method is utilized to establish surrogate model for cable damage detection. • Effect of material uncertainties on cable damage prediction analysis are considered. • The proposed computational framework can be utilized in cable damage identification and time-dependent analysis. This paper proposes a novel machine learning-based cable damage detection model to investigate the upper and lower bounds of bridges' cable damage degrees under the effects of corrosion and fire. In the proposed approach, the surrogate model for bridge cable damage detection under stochastic effects of corrosion and fire was established by combining machine learning and finite-element analysis to estimate the remaining life of cables. Then the accuracy and generalization performance of three typical machine learning methods for cable damage prediction are compared, such as Back Propagation neural network(BPNN), Radial Basis Function neural network(RBFNN) and Least Square-Support Vector Machine (LS-SVM). It is conducted that LS-SVM owns better prediction accuracy for cable damage under the coupling effects of corrosion and fire than the others. Additionally, the LS-SVM surrogate model combined with stochastic analysis and time-dependent deterioration model of steel wires under corrosion and fire is used to obtain the upper and lower bounds of cable damage under coupling effect of corrosion and fire. The proposed surrogate model can assist management in diagnosing and evaluating cable damage more quickly, efficiently, and flexibly once the real-time monitoring data is obtained. In addition, the surrogate model can guide bridge maintenance in advance. [ABSTRACT FROM AUTHOR]

Abstract: This work investigated thermal stability of fumed silica based thermal insulating composites prepared by dry molding technology. The results showed that the composites could keep excellent thermal stability at the temperatures below 800°C. However, when the samples were used at higher temperatures (>800°C), the volume shrinkage increased sharply, which directly led to a serious deformation and then affected thermal insulating properties in applications. The utilization of fumed alumina could significantly improve thermal stability of the composites. When 5wt.% fumed alumina was added, the volume shrinkage decreased from 10.49% to 3.47% at 1000°C. The desirable results would be achieved by adjusting the amount of fumed alumina according to practical using temperature. In addition, field emission scanning electron microscope (FESEM) and X-ray diffraction (XRD) were employed to characterize the microstructure and phase transformations of the composites treated at different temperatures. [Copyright &y& Elsevier]

Abstract: Mineral powders were added into fumed silica as IR opacifers in order to develop opacified thermal insulating composites for application at high temperatures up to 1000°C. The opacifying effect was evaluated with effective specific extinction. The results indicated that opacifiers could effectively block IR radiation heat transfer and improve thermal insulating properties of fumed silica. Among four opacifiers investigated in this paper, SiC was proved to be the best one for excellent extincting performance. When SiC was adopted with average particle size of 3.029μm and mass ratio of 25%, the values of effective specific extinction increased from less than 12.6 m2/kg to about 55 m2/kg in the wavelength range from 2.5 to 7μm. It was demonstrated that fumed silica-opacifier composites are efficient high temperature insulating materials. [Copyright &y& Elsevier]

[Display omitted] • Cyano group (CN)'s monomer-specific affinity determines the rapid Pd-Pt separation. • MnHCF can adsorb 90.30 % of Pd(Ⅱ) with ∼ 5 min at low initial concentrations of 10 ppm. • Electron-losing of C and N jointly contributes to the formation of N -Pd coordination bonds. • The strong and direct coordination between CN and Pd(Ⅱ) drives the rapid and selective adsorption. Rapid separation of low concentration palladium (Pd) from Pd-Platinum (Pt) coexisting systems remains a formidable challenge, primarily due to the undifferentiated substitution of ligands in Pd/Pt complexes by adsorption sites. The development of an adsorbent featuring monomer-specific affinity adsorption sites for Pd/Pt could mitigate this drawback. Herein, Manganese hexacyanoferrate (MnHCF) possessing the sensitivity and specificity to Pd ions (Pd(II)) was synthesized via the facile co-precipitation method. MnHCF could rapidly and selectively capture 90.30 % of Pd(II) from a 10 ppm Pd-Pt coexisting system within just 5 min. Spectroscopic analyses and density functional theory (DFT) calculations indicated that cyano-group (CN) in MnHCF exhibited the monomer-specific affinity for targeted capturing Pd via the direct and strong coordination interaction (Fe-CN-PdCl 2), which was co-determined by the electron-losing of C (0.06 e) and N (0.07 e) atom. At the same time, CN could neither react directly with the fully coordinated [PtCl 6 ]2− species nor substitute the Cl− ligand, both of which contributed to the non-adsorption of Pt, thus triggering the Pd-Pt separation. This study provides a promising candidate adsorbent for practical applications in platinum group metals recovery by the design of adsorption sites with monomer-specific affinity. [ABSTRACT FROM AUTHOR]

• Modified vermiculite achieved a better expansibility under microwave irradiation. • A novel quantitative analysis method of microwave energy absorption was proposed. • Influence mechanism of Mg2+ modification on microwave absorption was analyzed. This work investigated the effect of microwave power on vermiculite expansibility for different exposure time and compared the changes after Mg2+ modification. The expansion ratio of the modified vermiculite sample reached up to 5.29 at 800 W with a significant increase of 23.89 % in contrast to the raw vermiculite sample. Aimed to quantify the microwave energy absorption of vermiculite, a novel method was proposed by employing water as a medium material due to its sensitivity to microwave energy. Using this method, the effect of microwave power on microwave energy absorption of vermiculite was studied. Meanwhile, the influence mechanism of Mg2+ modification on microwave energy absorption of vermiculite was analyzed by means of energy dispersive X-ray spectroscopy and thermogravimetric-differential scanning calorimeter. Mg2+ modification could significantly improve the microwave energy absorption ability of vermiculite, which was mainly ascribed to the increase of interlayer water content through Mg2+ hydration reaction. [ABSTRACT FROM AUTHOR]

Developing nanoporous thermal insulation materials is an effective method for solving energy consumption problems. In this study, fumed silica based thermal insulating composite was prepared using a novel dry molding method. Thermal conductivity was measured using a guarded hot plate method in the steady state. The results indicated that this composite exhibited excellent thermal insulating performance, achieving an ultra-low thermal conductivity of 0.0205 W/mK at 100 °C. By analyzing the microstructure using field emission scanning electron microscopy (FESEM), we found that the fiber surface was modified by a 12 μm-thick layer of fumed silica particles that reduced solid heat transfer. However, at high temperatures, thermal insulating performance decreased rapidly, and thermal conductivity reached up to 0.119 W/mK at 500 °C. Based on this problem, a heat transfer model was constructed to explain micro-nano scale heat transfer mechanisms of this composite. The results indicated that gas-solid coupled thermal conductivity occupied a large proportion of 78.3% at 100 °C, but the value was only 0.015 W/mK. As the serving temperature increased, radiative heat transfer gradually occupied the dominant position in total heat transfer. Radiative thermal conductivity reached up to 0.101 W/mK at 500 °C, which was approximately 93.3% of total thermal conductivity. Therefore, it was apparent that the increase in radiative heat transfer was the main cause of the decline in thermal insulating performance at high temperatures. Additionally, the effect of the fiber mass ratio on thermal conductivity was investigated at various temperatures. Empirical and simulated data were compared, and the results revealed that the heat transfer model was basically consistent with experimental findings, achieving a mean error of only 4.78%. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microwave-activated persulfate is innovatively applied in cyanide degradation. • Cyanides in SPL can be completely degraded in 3 mins. • The degradation mechanism of Fe-CNs was analyzed systematically. • The persulfate can be activated to generate SO 4 − by Fe (II) in ferricyanide. Cyanide in spent potlining (SPL) is primarily present as sodium cyanide (NaCN) and iron (II, III) cyanide complexes (Fe-CNs). NaCN is easy to degrade, while Fe-CNs is extremely difficult to degrade. In this work, a novel microwave-activated persulfate technology (MW-PS) was firstly proposed to degrade Fe-CNs promptly and efficiently. The removal rate of 99.88 % was achieved within 180 s under optimal conditions of pH = 10.15, [oxidant]:[Fe-CNs] molar ratio of 5:1, and microwave power of 300 W. The remaining total cyanide content was less than 0.04 mg·L−1. The degradation mechanism of ferrocyanide (II) and ferricyanide (III) in the MW-PS degradation system was systematically analyzed through electron paramagnetic resonance (EPR) and element identification techniques. The ROS (SO 4 −, HO, O 2 −, and 1O 2) generated under microwave activation and first attacked the C-Fe complex bond in Fe-CNs, causing the bond to dissociate and release the free CN−, and then CN− was thoroughly oxidized. This work develops a simple and high-efficiency decyanation technology for complex cyanide contained industrial waste disposal. [ABSTRACT FROM AUTHOR]

A novel approach is proposed, combining pyrometallurgical and hydrometallurgical processes, to enhance the recovery of Fe and Al while effectively breaking down the mineral composition of red mud. The study delves into the roasting reduction behavior and conversion mechanism of red mud, utilizing thermodynamic analysis and conducting roasting experiments. Extensive investigations were conducted to analyze the impact of roasting temperature and time on the carbothermal reduction of red mud. The results indicate that the most favorable leaching effect of iron and aluminum from red mud was achieved after roasting at 1000 °C for 45 min. The behavior of roasted red mud during acid leaching was meticulously explored. During the roasting process, the majority of hematite in the red mud underwent reduction to wustite (FeO) and zero-valent iron, while the aluminum-bearing minerals melted and decomposed to form NaAlSiO 4 and Ca 2 Al 2 SiO 7 , along with other substances. The formation of low-valent and independently present iron products played a role in achieving high Fe leaching efficiency. The presence of Ca and Al-containing compounds such as Ca 2 Al 2 SiO 7 in the product of roasting proved difficult to leach, leading to poor Al leaching efficiency. The acid leaching process exhibited promising results, with maximum leaching efficiency of iron and aluminum reaching 95.7% and 72.5%, respectively. This success can be attributed to the control over experimental conditions, which allowed for the generation of desired iron oxides with various valence states. • A controlled reduction process for red mud roasting is proposed. • The recovery of iron from red mud exceeded 95%. • The directions of physical phase changes and valence transformations of iron and aluminum during roasting were traced. • A definite direction was given for the subsequent improvement of the process of aluminum recycling. [ABSTRACT FROM AUTHOR]

• Time-dependent nonlinear buckling behaviour of 3D concrete-filled steel tubular (CFST) arch structures considering both random and interval uncertainties were investigated. • Critical nonlinear limit and bifurcation buckling loads were formulated using Chebyshev surrogate model strategy combined with finite element method. • The present method can accurately predict the critical buckling loads and load–displacement paths at any time of the loading age. • The present approach is capable of analysing nonlinear buckling of complex 3D structures with hybrid random interval uncertainties. Limit point and bifurcation buckling loads are critical concerns in structural stability design. With the inevitable viscoelastic effects of creep and shrinkage in concrete, such critical buckling points may vary due to the time-dependent change of equilibrium configuration. Furthermore, the intrinsic uncertainty and natural randomness in the geometry and material characteristics would affect the structural stability performance significantly. The present study provides a new robust method, called the generalized Chebyshev surrogate model-based sampling approach, in assessing the time-dependent nonlinear buckling behaviour of 3D concrete-filled steel tubular (CFST) arch structures when both random and interval uncertainties are involved. In the proposed approach, the relationships between the uncertain parameters and the critical nonlinear limit and bifurcation buckling loads are formulated using Chebyshev surrogate model strategy combined with finite element method. The extreme bounds of the statistical features, including means, standard deviations, of the critical nonlinear buckling loads are furnished by using Monte Carlo method and Quasi Monte Carlo simulation method. Finally, the applicability and the validity of the proposed approach are illustrated with a series of numerical investigations. [ABSTRACT FROM AUTHOR]

The present study aimed to increase the utilization of phosphogypsum and reduce cement consumption. Single-factor experiments were designed to the effects of water-cement ratio (0.45–0.30), silica fume (1 %∼7 %), cement dosage (0 %∼20 %), and the RPG/HPG (20/80–0/100) on mechanical properties of phosphogypsum-based concretes (PGBCs). A new phosphogypsum-based concrete was prepared to meet the compressive strength requirement of C30 grade. The maximum 28d compressive strength of this PGBC reached 45.1 MPa. Simultaneously, the effect mechanisms of above four factors on the mechanical properties of PGBCs were discussed by combining XRD and SEM results. Moreover, the volume stability, elastic parameters, and compressive constitutive model of this PGBC with compressive strength above 30 MPa were investigated. This PGBC used more than 80 % phosphogypsum and 10∼20 % cement, exhibiting well economy and environmental friendliness. Moreover, the constitutive model was established to well predict the compressive behavior of PGBC with different RPG/HPG relative ratios. This PGBC had better volume stability and weaker deformation resistance than cement-based concrete. The present results can provide more theoretical and technical supports for the large utilization of PG. • PGBC is prepared with a large amount of PG as a cementing material. • The effects of four facters on the strength of PGBC were discussed. • The strength formation mechanism of PGBC were discussed by XRD&SEM. • A damage constitutive model with good correlation coefficient was established. • Providing theoretical and technical supports for the efficient utilization of PG. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dual electric field is constructed in Bi x O y I z /g-C 3 N 4 to enhance tetracycline removal. • Interfacial electric field achieves spatial separation of photogenerated carriers. • Enhanced internal electric field accelerates bulk charge separation and transfer. • This work provides a new perspective to separate bulk charge in heterojunctions. The electric fields created by semiconductor heterojunctions often only separated photogenerated charges at component interface, not sufficiently inhibiting carriers' recombination in their bulk phases. Herein, we introduced the enhanced bulk internal electric field into Bi x O y I z /g-C 3 N 4 heterojunction, constructing a dual electric field structure through in-situ precipitation and calcination to boost photocharge separation and transfer at both the interface and the bulk. The interfacial electric field created by heterojunction boosted the photocharge separation, and the enhanced internal electric field resulting from iodine reduction improved the bulk charge dynamics of Bi x O y I z. The dual electric field endowed Bi x O y I z /g-C 3 N 4 with high photocatalytic activity and broad application potential. Specifically, the photocatalytic reaction rate constants of Bi x O y I z /g-C 3 N 4 calcined at 460 °C for tetracycline removal reached 0.024 min−1, which was 3.42 times higher than that of BiOI/g-C 3 N 4. The electron paramagnetic resonance (EPR) and scavenging experiments proved that ·O 2 − was the predominant active species in oxidizing tetracycline. The experiments on simulated real water showed that Bi x O y I z /g-C 3 N 4 has a broad range of pH applicability, strong resistance to anionic interference, and good cycling performance. This work provided new insights for inhibiting bulk phase photocharge recombination of individual components in heterojunctions. [ABSTRACT FROM AUTHOR]

Spent potliner (SPL) has been listed as a hazardous waste derived from aluminum electrolysis production with high cyanide content. In this study, a novel microwave-sensitizer synergistic technique was proposed to rapidly remove cyanides in SPL. The occurrence states and removal behavior of cyanide in SPL were studied systematically. The results show that cyanide in SPL mainly exists in the form of sodium cyanide and ferricyanide. The maximum cyanide removal rate of 96.67% was successfully achieved under the experimental conditions. Meanwhile, the synergistic removal mechanisms were comprehensively investigated by XRD, XRF, TG-DTA, TG-MS, and FactSage thermal simulation software. The sensitizer Fe 2 O 3 can accelerate the decyanation reaction by decreasing activation energy and acting as an oxidant. This study not only develops a high-efficiency and rapid cyanide removal technique, but also provides theoretical guidance for non-hazardous treatment of other cyanogens-containing wastes. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, the sugarcane bagasse solid waste was used as raw material to prepare a novel bagasse biochar/ferrites (BB/FE) nanocomposite by one-step microwave pyrolysis method. This nanocomposite was used to adsorb As(V) in wastewater and the maximum As(V) adsorption capacity of 12.8 mg/g was successfully achieved under the experimental conditions. The synergistic effect of bagasse biochar and ferrites on As(V) adsorption was comprehensively investigated by TEM, FT-IR, XPS, adsorption thermodynamics and kinetics analysis, and DFT calculations. The results showed that the excellent As(V) adsorption performance of the BB/FE nanocomposite was attributed to the synergistic effects including electrostatic interaction, redox reaction, and complexation. This study not only develops a new pathway for bagasse resource utilization, but also provides theoretical guidance for design and preparation of high-performance nanocomposite adsorbents. [Display omitted] • A novel BB/FE nanocomposite was prepared via one-step microwave pyrolysis method based on sugarcane bagasse solid waste. • The BB/FE nanocomposite exhibited excellent As(V) adsorption performance. • The synergistic effect of bagasse biochar and ferrites on As(V) adsorption was comprehensively investigated. [ABSTRACT FROM AUTHOR]

Grey fixed weight clustering (GFWC) method is studied to predict the slagging tendency of biomass fuels combustion. Then the results of the GFWC method were verified and compared with experimental results. In the experiment, bagasse was chosen as an example to prepare ash from three different pretreatment groups (non-washing (NW), water-washing (WW), acid-washing (AW)) and two samples adding kaolin and calcite respectively. The degree of slagging was determined by measuring the ash melting point temperature with the ash melting point analyzer and observing the structural morphology of the particles by the scanning electron microscope (SEM). The GFWC method was used to synthesize the five single slagging prediction indexes, and a mathematical model for the evaluation of slagging was proposed to improve the accuracy of the evaluation results. Furthermore, the accuracy and applicability of the GFWC method for the estimation of slagging tendency of 25 kinds of biomass were tested. Compared with SI method and ternary equilibrium phase diagram, the estimation of GFWC method can avoid the uncertainty and it agreed with the SEM characteristics and ash fusibility temperatures (AFT). This study provides a new reference for biofuel slagging trend estimation based on ash composition. [Display omitted] • The GFWC model was proposed to evaluate the slagging tendency. • The effects of pretreatment and additive on slagging tendency were compared. • The accuracy of the algorithm was verified through experiments. • The other 25 biomass slagging tendencies were estimated by GFWCM. • Compared with SI and SCK system diagram, GFWCM can avoid the uncertainty. [ABSTRACT FROM AUTHOR]

Adsorption for recovery of low-concentration platinum (Pt) from the complex composition of acidic digestates was challenging because of slow kinetic and poor affinity. It was expected to be overcome by the improvement of pore size distribution and adsorption site activity. Herein, a series of Prussian blue etchings (PBE) with porosity-rich and activity-high cyano (CN) was synthesized to recover low-concentration Pt. The N 2 isotherm results showed that the pore structure evolved from mesoporous to microporous. The Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and density functional theory (DFT) calculations results revealed that the modulation of electronic structure converted FeII to FeIII in [FeII(CN) 6 ]4−. The coexistence of micro- and meso-pore structures provided channels to accelerate adsorption and ensured PtII enrichment. The regulation of Fe valence state activated CN, which reinforced the strength of coordination interaction between Pt and Fe-CN- at N-atom. The adsorption rate and maximum capacity of PBE1 were 4.4 and 2.5 times higher than those of PB, respectively, due to the dual efficacy of accelerated kinetic and reinforced coordination. This study systematically analyzes the pivotal role of pore and electronic structure modulation in adsorption kinetic and affinity, which provides a novel strategy for PtII targeted recovery. [Display omitted] • A porosity-rich and CN-activated Prussian blue is prepared by simple acid etching. • PBE1 exhibits 2.5- and 4.4-fold rise in adsorption capacity and rate compared to PB. • Modulating pore structure accelerates adsorption kinetic and ensures PtII enrichment. • Regulating Fe valence state to activate CN and reinforce coordination with PtII. [ABSTRACT FROM AUTHOR]

In this study, a sugarcane bagasse biochar/nano-iron oxide composite was prepared via a one-pot pyrolysis method by using the sugarcane bagasse-based solid waste and microwave as the raw material and energy source, respectively. The developed composite was characterized by BET, XRD, FT-IR and TEM and was applied for the removal of Cr (VI) from water. The composite was observed to be mainly composed of amorphous carbon, Fe 3 O 4 and Fe 2 O 3. The iron oxides were uniformly embedded on the surface of the carbon layer by van der Waals force. The sugarcane bagasse-based biochar/nano-iron oxide composite material exhibited an optimal Cr (VI) adsorption capacity of 55 mg/g under the experimental conditions specified in this study. The Cr (VI) adsorption mechanism of the Fe 2 O 3 /Fe 3 O 4 /WBC composite was explained through FTIR, XPS, charge transfer analyses, and density functional theory calculations (DFT). The deposition of Cr (VI) on the surface of the composite was attributed to electrostatic interaction, redox reactions and complexation between the Fe 2 O 3 /Fe 3 O 4 /WBC composite and Cr (VI) contained in the solution. [Display omitted] • A sugarcane bagasse-based biochar/nano-iron oxide composite was prepared via a one-pot pyrolysis method. • This composite features a more uniform distribution of iron oxides and a significantly improved Cr (VI) adsorption capacity. • The Cr (VI) adsorption of this composite is attributed to electrostatic interaction, complexation and redox reactions. [ABSTRACT FROM AUTHOR]

While semisupervised methods based on graph convolutional networks (GCNs) can achieve good results in hyperspectral image (HSI) classification, their performance is limited as they rely only on spatial–spectral similarity when constructing local adjacency graphs. Moreover, relying on local adjacency graphs can limit the ability of the methods to ensure the consistency of global feature in complex hyperspectral remote sensing environments. Using the spatial–spectral information is typically not sufficient for providing a reliable similarity measurement to construct a global graph when the spectral variability is large and the spatial distance is long in intraclass pixels. To address this issue, this article presents a novel globally consistent GCN (GCGCN) for HSI classification. According to the proposed method, a local reliable initial graph is first built from inherent spatial–spectral information by considering this graph as a variable to optimize. Then, adaptive global high-order neighbors are explored to capture the underlying rich spatial contextual information by utilizing the graph topological consistent connectivity instead of the common strategy of using only the spatial–spectral similarity measurement. Finally, the adaptive global high-order graph structure and two-layer networks are combined to achieve the global feature smoothing of the same class samples and maintain high global feature consistency. The proposed GCGCN method is evaluated on three real HSI data sets to demonstrate its superiority compared to ten different classification methods. Moreover, the proposed GCGCN method achieves state-of-the-art classification results on three data sets in terms of four classification evaluation metrics, including overall accuracy (OA), kappa coefficient (KC), average accuracy (AA), and class accuracy (CA). [ABSTRACT FROM AUTHOR]

• Mg-Fe binary metal oxide are loaded onto carbon fiber by microwave pyrolysis. • The adsorption capacity of composite adsorbent has reached a new height (249 mg/g). • The proposed adsorption mechanism was verified by DFT calculation for the first time. • Gibbs free energy (ΔG) was used to verify the influence mechanism and of co-existing anions. Improving the adsorption capacity and efficient separation of fluorine removal adsorbents will greatly enhance their cost-performance in applications. In order to explore the excellent performance of fluoride removal adsorbents, in this work, MgO, Fe 2 O 3 , and Fe 3 O 4 nanoparticles were loaded onto carbon fiber by microwave pyrolysis to prepare a magnetic composite adsorbent material (MgO/Fe 2 O 3 /Fe 3 O 4 /CF) for fluoride removal. To verify the payload of metal oxide on the carbon foam, the adsorbent was thoroughly characterized. In application, the adsorption process is consistent with the pseudo-second-order kinetic model and Langmuir isotherm model, and the highest adsorption capacity reached 249.0 mg/g. Such a high adsorption capacity is rare among the complex adsorbents reported in the past. In addition, a possible mechanism was proposed by the analysis of EDS, XRD, FTIR, XPS, and water chemical equilibrium parameters. The reactivity, adsorption energy between F− and metal oxides, and interaction configurations of F− with hydrated ions were calculated using Density Functional Theory (DFT). Moreover, the Gibbs free energy change (ΔG) of ion exchange reactions between anions (OH–, Br−, Cl−, CO 3 2–, NO3–, SO 4 2−, HCO 3 –, and PO 4 3−) and different forms of fluorine in solution was calculated to express the inhibitory behavior. Finally, the adsorbent can be separated efficiently from the water by means of an applied magnetic field, and then it can be recycled. In summary, the research content in this paper not only discusses an excellent fluorine removal material but also makes up for the partial absence of the influencing factors in the adsorption mechanisms of MgO and Fe 2 O 3. [ABSTRACT FROM AUTHOR]

An environmentally friendly and simple homogeneous precipitation method synthesized MgO nanoparticles with highly efficient fluorine removal. The prepared MgO nanoparticles have an average size of 53 nm, the composition and structure of MgO nanoparticles were analyzed by XRD, SEM, TEM, STEM and BET. The high specific surface area (242.6 m2/g) and abundant pores (1.18 cm3/g) of MgO nanoparticles contribute to the increase of adsorption sites. The adsorption properties of MgO nanoparticles for fluorine were investigated by discussing the adsorption kinetics, isotherms and thermodynamics, the outcomes demonstrated that the Pseudo-second-order kinetics, Langmuir isotherm model and Freundlich model could describe the adsorption behavior for fluorine, and the maximum adsorption capacity is 372.65 mg/g. The Gibbs free energy change G°< 0 at different temperatures proves that the adsorption for fluorine by MgO is endothermic and spontaneous. In addition, the findings from FT-IR, XRD, XPS and hydrochemical equilibrium analysis demonstrate that the substances that play an adsorption role in MgO nanoparticles, and analyzed the reason why MgO nanoparticles have better adsorption properties than commercial MgO. Moreover, the environmental factors such as pH (3−10) and coexisting ions (Cl-, NO 3 2-, SO 4 2-, HCO 3 -, CO 3 2-, PO 4 3-) that may affect adsorption property in practical applications are also explored. The separation percentage of the adsorbent from the aqueous solution after adsorption indicates that it can be easily separated from water by filtration. Hence, the MgO nanoparticles in this study can be considered as a fluorine adsorbent with great potential. [Display omitted] • Using a clean and low-energy-consumption precipitation method prepared MgO nanoparticles with an average size of 50.3 nm. • The maximum adsorption capacity of MgO nanoparticles for fluoride reached a new high value of 372.65 mg/g. • It is found that MgO nanoparticles have better adsorption properties than commercial MgO. • The substances that play an adsorption role in MgO nanoparticles are mainly Mg2+ and MgOH+ formed by the reaction of MgO and water. • MgO nanoparticle adsorbents can be easily separated from water by filtration. [ABSTRACT FROM AUTHOR]

Bentonite is an important clay for preparation of adsorbents for potential treatment of industrial effluents. However, due to its natural occurrence as fine particles and swelling after moisture absorption, bentonite is difficult to be separated from the liquid for regeneration purpose, which limits its application in effluent treatment. In this study, two different bentonite-polypropylene composites were synthesized, i.e., with and without pore-enlarging treatment. They both showed strong ability to resist hydraulic agitation damage with a small breakage rate in water. The obtained results from SEM and XRD characterization revealed that the compounding of bentonite with the polypropylene was a physical process, and the structural characteristics of bentonite particles were maintained in the new products. The granular composite adsorbents were effective in removing Pb 2+ in aqueous solution. The suggested pore-enlarging treatment was verified as a successful operation to increase greatly the adsorption rate of contaminants on the granular bentonite composite. [ABSTRACT FROM AUTHOR]

[Display omitted] • Regulable O-doped graphitic carbon nitride (OCN) has been fabricated by a facile one-step annealing strategy. • The introduced O enhanced photocatalytic efficiency by 29 times. • The upshift of CB potential is responsible for the generation of O 2 ∙-. • The doped O is conducive to the separation of photogenerated carriers. Oxygen atoms with lone pair electrons have been used to improve the photocatalytic activity of graphitic carbon nitride (g-C 3 N 4). Herein, a one-step annealing strategy without co precursor is used to prepare O-doped graphitic carbon nitride (OCN) for photocatalytic degradation of bisphenol A (BPA). The band structure and photocatalytic performance are tuned by simply controlling the heating time. The degradation rate constant for OCN6 is improved by 29 times compared to the original CN. Experimental and the density functional theory calculated results prove that the doped-O is the key factor in promoting photocatalytic performance. The introduced O not only adjusts local electron density, but also decreases the band gap to boost e - transfer and carrier generation and separation. The elevated conductive band energy is responsible for producing O 2 ∙-, which is the dominated reactive oxygen species. This work offers a simple and effective way for the self-modification of metal-free catalysts to resolve environmental issues. [ABSTRACT FROM AUTHOR]

The plane-wave expansion method and coupled-mode theory were used to calculate the reflection spectra of photonic crystal fiber (PCF) Bragg gratings (BGs) filled with liquids (PCF-BGs-liquids). The simulated reflection spectra of the PCF-BGs-liquids agree well with the reported experimental results. The simulated Bragg wavelength shift of the PCF-BGs filled with optical index matched liquid is 100 pm/ °C as the temperature changes from 25 °C to 65 °C. Therefore, PCF-BGs-liquids can be used as high sensitivity temperature sensors. [ABSTRACT FROM AUTHOR]