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Hydrophobic coatings that could survive in harsh environment have a wide range of applications from industry to houseware. However, the state‐of‐the‐art polymer‐based coatings cannot meet such requirements due to their low melting point and poor wear resistance. In this study, we reported a plasma sprayed ceramic coating made of ceria with exceptional hydrophobicity, high‐temperature stability, and good wear resistance. The coating exhibited a water contact angle (WCA) up to 139°, due to the intrinsic hydrophobicity of ceria and unique surface morphology produced by plasma spraying. The WCA only slightly decreased to 131° after annealing at 773 K. In addition, the polished coating (WCA ~ 116°) was still more hydrophobic than the sintered bulk specimen (WCA ~ 95°) with the same composition and roughness, which can be attributed to the surface chemistry change induced by Ar+ ion bombing by plasma. It is believed that such robust hydrophobic coating should have great potential in engineering application. [ABSTRACT FROM AUTHOR]

Construction sites remain one of the most hazardous workplaces globally. To improve workplace safety in the construction industry and reduce the personal injuries and socioeconomic impacts resulting from workplace accidents, tacit knowledge containing fundamental causes of accidents or specific contextual factors can be extracted from past accident narrative reports. However, manually analyzing unstructured or semistructured textual data stored in records is a daunting task, and requires the use of automated and intelligent technologies to achieve rapid and accurate knowledge acquisition. Therefore, this paper proposes a text self-classification model based on deep learning natural language processing (NLP) technology for automated classification of construction site accident cases by accident type. First, combined with two statistical measures, mutual information and information entropy, the preprocessed text data were subjected to phrase segmentation to identify more complete and accurate accident precursor information without human intervention. Then a complete multilayer and multisize convolutional neural network (CNN) model was constructed using pretrained Word2Vec word embeddings for text self-classification tasks. Finally, the test results of the CNN classification algorithm were compared with the practical application results of three shallow learning algorithms, and the performance of different types of classification algorithms was evaluated. The results showed that the CNN-based deep learning algorithm developed in this paper demonstrated excellent feature extraction and learning abilities in the task of automatic text classification in the field of NLP. This not only demonstrated that reliable accident prevention knowledge could be obtained from the textual descriptions of construction accidents, but also provided a novel model reference for document archiving and information retrieval. [ABSTRACT FROM AUTHOR]

This paper investigates the valuation of vulnerable European options considering the market prices of common systematic jump risks under regime-switching jump-diffusion models. The way of regime-switching Esscher transform is adopted to identify an equivalent martingale measure for pricing vulnerable European options. Explicit analytical pricing formulae for vulnerable European options are derived by risk-neutral pricing theory. For comparison, the other two cases are also considered separately. The first case considers all jump risks as unsystematic risks while the second one assumes all jumps risks to be systematic risks. Numerical examples for the valuation of vulnerable European options are provided to illustrate our results and indicate the influence of the market prices of jump risks on the valuation of vulnerable European options. [ABSTRACT FROM AUTHOR]

Buckwheat plant height is an important indicator for producers. Due to the decline in agricultural labor, the automatic and real-time acquisition of crop growth information will become a prominent issue for farms in the future. To address this problem, we focused on stereo vision and a regression convolutional neural network (CNN) in order to estimate buckwheat plant height. MobileNet V3 Small, NasNet Mobile, RegNet Y002, EfficientNet V2 B0, MobileNet V3 Large, NasNet Large, RegNet Y008, and EfficientNet V2 L were modified into regression CNNs. Through a five-fold cross-validation of the modeling data, the modified RegNet Y008 was selected as the optimal estimation model. Based on the depth and contour information of buckwheat depth image, the mean absolute error (MAE), root mean square error (RMSE), mean square error (MSE), and mean relative error (MRE) when estimating plant height were 0.56 cm, 0.73 cm, 0.54 cm, and 1.7%, respectively. The coefficient of determination (R2) value between the estimated and measured results was 0.9994. Combined with the LabVIEW software development platform, this method can estimate buckwheat accurately, quickly, and automatically. This work contributes to the automatic management of farms. [ABSTRACT FROM AUTHOR]

NiS 2 hollow spheres with controllable size have been synthesized by a facile hydrothermal method through the exchanging reaction between rod-like supramolecular precursor and l -cysteine. Through modifying the diameter of rod-like precursor as template, accompanied by concomitant Rayleigh instability and chemical nonequilibrium interdiffusion, the size of NiS 2 hollow sphere can be tuned ranging from nanosize to microsize. The hollow morphology of as-obtained product was attributed to the Kirkendall effect involving different transport rates for Ni and S ions. Owing to the relatively large specific area, the as-obtained nanoscale NiS 2 hollow sphere manifest remarkable photo co-catalytic performance for H 2 production, which generate 5.8 mmol of H 2 gas under the irradiation of visible light after 6 h and 0.97 mmol/h of average H 2 production rate, indicating superior H 2 production performance of NiS 2 hollow spheres. [ABSTRACT FROM AUTHOR]

Currently, the MgO expansion agent is widely used to reduce the cracking risk of concrete. The influence of MgO reactivity (50 s and 300 s) and dosage (0, 4 wt.% and 8 wt.%, by weight of binder) on the air void, pore structure, permeability and freezing–thawing (F–T) resistance of concrete were studied. The results indicate (1) the addition of 4–8 wt.% reactive MgO (with reactivity of 50 s and termed as M50 thereafter) and weak reactive MgO (with reactivity of 300 s and termed M300 thereafter) lowers the concrete's compressive strength by 4.4–17.2%, 3.9–16.4% and 1.9–14.6% at 3, 28 and 180 days, respectively. The increase in MgO dosage and reactivity tends to further reduce the concrete strength at all hydration ages. (2) Permeability of the concrete is closely related to the pore structure. M50 can densify the pore structure and lower the fraction of large capillary pores at an early age, thus it is beneficial for the impermeability of concrete. In contrast, M300 can enhance the 180-day impermeability of concrete since it can densify the pore structure only at a late age. (3) The influence of MgO on F–T resistance is minor since MgO could not change the air void parameters. (5) MgO concretes exhibit obvious fractal characteristics. The fractal dimension of the pore surface (Ds) exhibits a close relationship with the permeability property of concrete. However, no correlation can be found between F–T resistance and Ds. [ABSTRACT FROM AUTHOR]

Hydrophobic coatings based on organic or ceramic materials usually suffer from low wear resistance and poor thermal stability, which limit their practical applications. Here we report a robust, hydrophobic CeO 2 /NiCoCrAlY composite coating prepared by air plasma spraying (APS), which shows superior wear resistance, excellent high-temperature stability and high bonding strength with the substrate. The coating can maintain its hydrophobicity after abrasion under 10 kPa over a 4 m distance, or after annealing at 773 K for 8 h. It also presents good corrosion resistance to protect the metallic substrate under corrosive working conditions. The CeO 2 /NiCoCrAlY composite coating provides a reliable and effective route to fabricate hydrophobic surfaces which may have potential applications in harsh environments. • CeO 2 /NiCoCrAlY composite coatings were prepared by APS. • The coating with 80% CeO 2 can maintain its hydrophobicity after abrasion under 10 kPa over a 4 m distance. • The coating with 80% CeO 2 can also maintain its hydrophobicity after annealing at 773 K for 8 h. • The coating can protect the substrate from corrosion. • The robust, hydrophobic and thermally-stable coating is promising to work under harsh environments. [ABSTRACT FROM AUTHOR]

Livestock dung, discarded crop straws, and residual plastic film are the primary agricultural non-point sources of pollution. For livestock dung and discarded crop straw, the general treatment focuses on compost, animal fodder, industrial raw material, and new energy. The development of degradable mulch film is the main way to solve pollution from residual plastic film. However, an effective way to solve the above three types of pollution simultaneously and use them for ecological circular agriculture has been less studied. In this study, using cow dung and flax straw wastes as raw materials, we prepared natural, fibre-based paper mulch using the rapid-Kothen method and analysed the film-forming mechanism. Based on the Van Soest method, the cow dung and flax straw waste contain abundant cellulose fibres: 36.75% and 54.69%, respectively. The tensile strength and tear strength of fibre paper mulch are 1.87 kN/m and 19.91 N/mm, respectively. To enhance the adaptability of the fibre paper mulch in humid environments, the surface of the mulch was treated with alkyl ketene dimer (AKD). The AKD-coated fibre paper mulch displays hydrophobic properties, indicated by a contact angle of 128° ± 2°. It has a wet tensile strength of 0.64 kN/m and a wet tear strength of 8.23 N/mm. Additionally, it exhibits a dry tensile strength and a tear strength of 2.13 kN/m and 16.43 N/mm, respectively. Notably, the dry tensile strength is increased by 16.31%. In this way, the livestock dung and discarded crop straw can be reused, reducing dung pollution and straw burning in livestock farms, and the final products can alleviate the residual film pollution simultaneously. [ABSTRACT FROM AUTHOR]

Enhancing the photocatalytic stability of Cu2O in the degradation of tetracycline is a great challenge in combating environmental water pollution because it is prone to deactivation by photocorrosion in aqueous environment. In this study, Cu2O/cellulose microfiber aerogel is synthesized through freeze‐drying, utilizing the self‐curling effect of cellulose and then calcined to produce Cu2O/C composite aerogel. The derived Cu2O/C composite aerogel features hollow carbon microfibers anchored with Cu2O nanocubes. Due to the curling structure and conductivity of the carbon microfibers, the photodegradation efficiency of the obtained Cu2O/C composite aerogel for tetracycline is drastically improved to 97.3% under 120 min of visible‐light irradiation, and remains a cycling photodegradation rate of 84.3% after 10 cycles. The Cu2O/C composite aerogel shows remarkable strategies for designing and constructing Cu2O‐based photocatalyst in the practical photodegradation of tetracycline under visible‐light exposure. [ABSTRACT FROM AUTHOR]

An auto-deformable supercapacitor which is composed of PPy(DBS) film (PPy doped with dodecyl benzene sulfonate anions, DBS−), reduced graphene oxide (rGO) film and Polyvinyl alcohol (PVA) gel electrolyte is fabricated. Benefiting from the synergy of flexible film electrodes and gel electrolyte, the volumetric effect of PPy(DBS) film produced by capacitance reaction is collected continually. The accumulated volumetric effect enables the as-designed supercapacitor to deform autonomously during the cyclic energy storage processes and generates more electrochemical active sites in PPy(DBS) film, which provides higher energy storage capacity for the supercapacitor. • Volumetric effect of PPy is collected and accumulated by synergy of flexible electrode and solid-state electrolyte. • The cumulative volumetric effect is applied to auto-deformable supercapacitor. • There is a quantitative relationship between the deformation degree and the capacitance. Polypyrrole (PPy) is one of the most extensively studied conducting polymers and it has promising application prospects in supercapacitors. However, PPy-based supercapacitors generally suffer from poor cycling stability due to the volumetric effect induced by ion doping/de-doping during the redox reactions. Therefore, the volumetric effect has usually been considered deleterious for supercapacitor applications. Herein, we demonstrate that the volumetric effect of PPy can be collected by synergy of flexible electrodes and solid-sate electrolytes. Furthermore, the accumulative volumetric effect is utilized in auto-deformable supercapacitors for the first time. The as-designed supercapacitor consists of flexible electrodes (PPy film, reduced graphene oxide (rGO) film) and a polyvinyl alcohol (PVA) gel electrolyte. When the redox reaction starts, the volumetric change of the PPy film induced by Na+ ion insertion is captured by the PVA gel electrolyte, resulting in mechanical deformation of the supercapacitor. As the accumulative volumetric effect drives greater deformation of the device, more electrochemically active sites are generated in the PPy film, leading to a higher energy storage capacity of the supercapacitor. Specifically, a certain correlation exists between the deformation degree and the energy storage capacity. As the deformation degree approaches 100% from 0%, the discharge capacity increases to 359 mF/cm3 from 101 mF/cm3. This auto-deformation characteristic endows the supercapacitor with subjective initiative, which establishes an important foundation for a smart energy storage device. [ABSTRACT FROM AUTHOR]

Water glass (WG) is generally considered to be the most effective activator to prepare alkali-activated slag (AAS) cement in terms of strength and durability. However, the rapid setting and hardening of WG activated slag results in rapid loss of fluidity of AAS concrete mixture, which limits its engineering application. In the paper, the effect of blended inorganic salts containing negative hydration ions on the fluidity, setting time and mechanical strength of AAS cement was studied. The hydration process and hydration products were used to explore the action mechanism. Ba(NO 3) 2 greatly delayed the hydration of AAS cement. The four inorganic salts (KCl, KNO 3 , KBr and NaCl) blended with a small amount of Ba(NO 3) 2 can improve both the initial fluidity and fluidity retention, and a wide setting time range can be obtained to meet engineering requirements. The compressive strength decreased with the increase of inorganic salts. The incorporation of inorganic salt did not change the composition of the main hydration products. Considering the fluidity required by construction, mechanical properties and the durability of structure, it is recommended to add 4%–5% KBr or KNO 3 blended with no more than 0.2% Ba(NO 3) 2 into AAS cement. [ABSTRACT FROM AUTHOR]

Industrial metabolism and symbiotic coupling has become the base paradigm of green, low-carbon development of coal mining. In the coal industrial symbiosis system (CISS), stability is increasingly fragile because of its unique industrial links and growth environment. Referring to the classic Lotka-Volterra population ecology model, and synthesizing the periodicity and time lag effects of industrial development, two entirely novel and more generalized CISS evolution models with time lag effects in the competitive and reciprocal scenarios are constructed respectively. Moreover, the conditions of CISS stability are proven and discussed through mathematical analysis. Simulation and theorem validation were carried out by taking the largest Chinese coal city, Ordos, as the research object. The main results are as follows. First, the time lag effect is an important factor leading to CISS instability. The shorter the time lag within the CISS, the better the collaboration between industries, and the easier it is that the CISS will achieve a stable ecological balance. Second, when the power of competition dominates, the development of industries within CISS will be inhibited; when the power of cooperation dominates, the evolution of CISS will toward a positive direction. Third, a certain degree of self-inhibition will contribute to the stable development of the industrial symbiosis system. At last, the social service industry not only can boost the industrial diversity within CISS, but also can promote the co-evolution of original and exogenous industries, which plays a positive role in the healthy and stable development of CISS. [ABSTRACT FROM AUTHOR]

Wire-shaped supercapacitors (WSSCs) are of considerable interest for next-generation wearable electronics. However, the poor stretchability of WSSCs based on inelastic yarn electrode seriously lead to the deficient size-adjustability of the devices. Herein, a novel kind of highly conductive, flexible and elastic yarn electrode has been put forward, which is realized by coating electro-active carbon nanotubes (CNTs) network onto the Ag-plated double-covered yarns (Ag-DCYs). On the one hand, highly conductive Ag-DCYs with “twining spring” architecture serve as the elastic substrate of the electrode. On the other hand, thin CNTs layer is uniformly wrapped on the whole yarns, which provides remarkable electrochemical capacitance for the electrode. Benefiting from the intriguing configuration, WSSCs based on the yarn electrode act as the efficient energy storage devices, which exhibit high volumetric energy density (4.17 mWh/cm 3 ), volumetric power density (1080 mW/cm 3 ), strong durability. More importantly, the integrated devices are randomly bendable and stretchable without the degradation of electrochemical performance. Such superior energy storage performance and steady electrochemical behaviors under high strain (150% maximum) have almost never been reported before. As a result, the WSSCs can be readily knitted with textiles and woven into different shapes, which distinctly represent the available self-stretchable and size-adjustable ability, thereby throwing light on a new avenue for the development of wearable electronics. [ABSTRACT FROM AUTHOR]

The agronomic technology of whole plastic-film mulching on double ridges has been widely promoted in the arid region of northwest China, which has caused serious residual film pollution in the field. Mechanized residual plastic-film collecting is the main way, but this way of residual plastic-film collecting is more complicated. To prove the effect of typical film-lifting parts on residual plastic-film collecting performance by a numerical simulation method, further evaluate and select the working parts suitable for residual plastic-film collecting and improve the collecting efficiency, virtual whole plastic-film mulching on double ridges needs to be established. In this study, the film-lifting parts and the double ridge with flexible, deformable, mulching, film interaction model was developed using the discrete element method (DEM). The interaction model was used to simulate the operation process of a typical third-order shovel, hug plate and elastic teeth film-lifting parts. Furthermore, the operation resistance, seed bed disturbance and collecting residual film form under different working conditions were analyzed. The simulation results show that: the disturbance of the ridge from strong to weak is the third-order shovel, elastic teeth and hug plate film-lifting parts; the crushing of the ridge soil from strong to weak is the elastic teeth, the hug plate and the third-order shovel film-lifting parts; the collecting film from strong to weak is the hug plate, elastic teeth and the third-order shovel film-lifting parts; the median value of the horizontal force fluctuation range of the ridge soil on the film-lifting parts is increased, and the increase trend is from large to small in the third-order shovel, elastic teeth and hug plate film-lifting parts (the third-order shovel is 5250 N, 6250 N and 7750 N; the hug plate is 3250 N, 3500 N and 4000 N; and the elastic teeth are 4150 N, 4550 N and 5450 N). The comparative analysis results show that the hug plate film-lifting parts are more suitable for the residual-film collecting of whole plastic-film mulching on double ridges. Field trials were carried out to verify the operational effectiveness of the hug plate film-lifting parts. The results show that the morphological changes of the recovered residual film and the simulated mulching film during the operation of the hug plate-type residual film machine, and the distribution of the surface properties of the ridge after the residual-film collecting are basically consistent with the simulation results, and the film pick-up rate of hug plate film-lifting parts reaches 95.20%, and the established discrete element interaction model is reliable. The research results can provide reference for the research and development of full film duopoly furrow-mechanized residual film-collecting agricultural equipment in the arid region of northwest China. [ABSTRACT FROM AUTHOR]

In the context of the depth adjustment of the global economy and wild fluctuations in energy prices, the vulnerability issue of the coal mining industrial ecosystem (CMIES) has seriously affected the sustainable development of the regional economy. Comparisons of CMIES health status at a regional level are worthy of being conducted. This not only contributes to understanding a particular coal mining area's situation in regards to CMIES vulnerability, but also helps to discover a meaningful benchmark to learn the experiences in terms of action programmes formulation. In this study, based on the analysis of the vulnerability response mechanism of CMIES to economic fluctuations, an initial indicator system for vulnerability assessment of CMIES was constructed. Ultimately, 14 vulnerability-evaluating indicators and their weights were obtained using rough set attribute reduction. Based on a composite CMIES Vulnerability Index (CVI), the Rough Set-Technique for Order Preference by Similarity to Ideal Solution-Rank-sum Ratio (RS-TOPSIS-RSR) methodology is proposed to conduct the CMIES vulnerability assessment process from an overall perspective. Using this methodology, 33 coal mining areas in China are ranked as well as grouped into three specific groups based on the CVI score. The results demonstrate the feasibility of the proposed method as a valuable tool for decision making and performance evaluation with multiple alternatives and criteria. [ABSTRACT FROM AUTHOR]

Graphene resonant sensors have shown strong competitiveness with respect to sensitivity and size. To advance the applications of graphene resonant sensors, the damage behaviors of graphene harmonic oscillators after thermal annealing and laser irradiation were investigated by morphology analysis and frequency domain vibration characteristics. The interface stress was proven to be the key factor that directly affected the yield of resonators. The resulting phenomenon could be improved by appropriately controlling the annealing temperature and size of resonators, thereby achieving membrane intactness of up to 96.4%. However, micro-cracks were found on the graphene sheets when continuous wave (CW) laser power was more than 4 mW. Moreover, the fluctuating light energy would also cause mechanical fatigue in addition to the photothermal effect, and the threshold damage power for the sinusoidally modulated laser was merely 2 mW. In this way, based on the amplitude-frequency surface morphology of the graphene resonator, the thermal time constant of the order of a few microseconds was confirmed to evaluate the damage of the graphene oscillator in situ and in real time, which could be further extended for those resonators using other 2D materials. [ABSTRACT FROM AUTHOR]

As the important electric loss of a graphene resonator, intrinsic current loss has received increasing attention, but the existing research is limited to qualitative analysis and approximate calculation. Based on the microscopic behavior of carriers, we have accurately established the calculation model of induced current loss, which is in good agreement with the existing experimental results. Compared with the previous models, the model in this work can not only fit the inverse V-shaped Q − Vdc curve well but also be compatible with the V-shaped Q − Vdc curve, which is beyond the reach of the previous models. In addition, the calculation results show that selecting the appropriate gate voltage combination when stimulating the graphene resonator can increase the quality factor by nearly 1–2 orders of magnitude. Furthermore, we reasonably explain the importance of DC gate voltage applied in the experiment compared with the case of non-DC gate voltage. This work realizes the accurate calculation of intrinsic current loss and is of great significance for reducing the intrinsic current loss in the practical application of graphene resonators. [ABSTRACT FROM AUTHOR]

Near-neutral salt activated slag cement has better performance in environmental protection and shrinkage behavior than common sodium silicate -activated slag (AAS) cement. However, the growth of mechanical performance is too slow, which limits its application. Reactive MgO can improve early mechanical properties, while it may have different effects on the shrinkage due to changes in alkali-activators. Two near-neutral salts, sodium carbonate (SC) and sodium sulfate (SS), were selected to prepare AAS cement. The influence of reactive MgO on autogenous and drying shrinkages was studied. The hydration process and pore structure were assessed with hydration heat and nitrogen adsorption, respectively. The phase composition was evaluated by thermogravimetry (TG/DTG) and X-ray diffraction (XRD). The results indicate that the addition of reactive MgO increases the autogenous shrinkage of SC and SS activated slag. This is mainly due to accelerated reaction by reactive MgO. The drying shrinkage of AAS mortars activated with SC increases first and then decreases with the increase in reactive MgO. For SS activated slag, the more the reactive MgO used, the lower the drying shrinkage is observed. This is related to the effect of reactive MgO on pore structure and hydration products. When reactive MgO increases from 2% to 10%, the mesopore in SC activated slag increases at first and then decreases, while the SS activated slag group shows a constant decrease. Reactive MgO promotes the formation of hydrotalcite in SC activated slag, while AFt is found in SS activated slag. Hydrotalcite and AFt are crystalline products, which are beneficial to inhibit drying shrinkage. [ABSTRACT FROM AUTHOR]

CO 2 methanation is a promising strategy to convert the greenhouse gas into synthetic natural gas, which is known as a clean fuel with higher energy density. Ni/CeO 2 is one of the active catalysts for CO 2 methanation reaction. However, Ni/CeO 2 with conventional metal/support structure suffers from the problem of nanocrystal coarsening during high-temperature reaction and thus decreasing catalytic activity. In this work, a Ni/CeO 2 catalyst with novel structure was designed and synthesized through impregnation of Ce-based metal organic framework (MOF) with Ni precursor followed by calcination process. Due to the confinement effect of ultra-small pores derived from the MOF, Ni/CeO 2 catalysts with ultrafine Ni nanoparticles, high dispersion and good thermostability were resulted. Among all the samples, Ni/CeO 2 calcined at 600 °C showed the best catalytic performance due to the highest amount of oxygen vacancies. This work demonstrates a facile way to synthesize a broad range of ultra-fine metal/metal oxide nanocomposite catalysts with high catalytic activity and good stability for various applications. [ABSTRACT FROM AUTHOR]

Self-standing film with desirable properties is a promising candidate for flexible electronic applications. Conducting polymers (CP) have intrinsic film forming and pseudocapacitive characteristics. However, pure CP films are rarely applied in energy storage devices due to their disordered molecular structure which would result in insufficient utilization of the supported active materials and apparent volumetric effect. The specific lamellar structure of 2D nanosheets is an ideal platform for CP growing into self-standing film with desirable structure. Herein, a facile interface engineering strategy is proposed for in-situ integrating 2D MoS 2 nanosheets into 3D polypyrrole (PPy) framework, in which dodecylbenzene sulfonate (DBS−) anions intercalate into MoS 2 nanosheets and guide PPy to grow into ordered molecular structure. The resultant self-standing films with PPy chains in a high degree of ordering can deliver a high area capacitance of 1200 mF/cm2 and a high volumetric capacitance of 325 F/cm3, which are significantly superior to pure PPy films and show a great potential for high performance flexible supercapacitor application. Image 1 [ABSTRACT FROM AUTHOR]

Designing defect‐rich MoS2/C architectures with three‐dimensional (3D) porous frame effectively improve the electrochemical performance of lithium‐ion batteries (LIBs) owing to the improved conductivity and decreased diffusion distance of Li+ ions for lithium storage. Herein, we report a reliable morphology engineering method combining with tunable defects to synthesize defect‐rich MoS2 nanosheets with a few layers entrapped carbon sheath, forming a 3D porous conductive network architecture. The defect‐rich MoS2 nanosheets with expanded interlayers can provide a shortened ion diffusion path, and realize the 3D Li+ diffusion with faster kinetics. A 3D conductive interconnected carbon network is able to improve interparticle conductivity, concurrently maintaining the structural integrity. Benefiting from these intriguing features, the as‐prepared MoS2/C architectures exhibit excellent electrochemical performance: a high reversible capacity of 1163 mAh g−1 at a current density of 0.1 A g−1 after 100 cycles and a high rate capability of 800 mAh g−1 at 5 A g−1. Defect content in MoS2/C architectures can be obtained by changing H2 concentration. Compared with the counterparts with few defects, the defect‐rich MoS2/C architectures show improved electrochemical stability with a superior cycle life, illustrating a highly reversible capacity of 751 mAh g−1 at 0.5 A g−1 after 500 cycles. [ABSTRACT FROM AUTHOR]

Microcystins (MCs) is a harmful toxin generated by blue‐green algae in water, which has seriously threatened the ecological safety of water and human body. It is urgent to develop new catalysts and techniques for the degradation of MCs. A feasible electrostatic self‐assembly method was carried out to synthesize BiVO4/g‐C3N4 heterojunction photocatalyst with highly efficient photocatalytic ability, where BiVO4 nanoplates with exposed {010} facets anchored to the g‐C3N4 ultrathin nanosheets. The morphology and microstructure of the heterojunction photocatalysts were identified by XRD, SEM, TEM, XPS, and BET. The g‐C3N4 nanosheets have huge surface area over 200 m2/g and abundant mesoporous ranging from 2‐20 nm, which provides tremendous contact area for BiVO4 nanoplates. Meanwhile, the introduction of BiVO4 led to red‐shift of the absorption spectrum of photocatalyst, which was characterized by UV‐vis diffuse reflection spectroscopy (DRS). Compared with pure BiVO4 and g‐C3N4, the BiVO4/g‐C3N4 heterojunction shows a drastically enhanced photocatalytic activity in degradation of microcystin‐LR (MC‐LR) in water. The MC‐LR could be removed within 15 minutes under the optimal ratio of BiVO4/g‐C3N4. The outstanding performance of the photocatalyst is attributed to synergetic effect of interface Z‐scheme heterojunction and high active facets {010} of BiVO4 nanoplates, which provides an efficient transfer pathway to separate photoinduced carriers meanwhile endows the photocatalysts with strong redox ability. [ABSTRACT FROM AUTHOR]

A novel method based on sound signals is proposed to realize realtime quantitative monitoring of abrasive belt conditions in robotic grinding system. Robotic belt grinding experiments are carried out on Inconel 718 alloy workpieces. The belt wear styles are observed under scanning electron microscope (SEM). The belt wear conditions are quantified by the grinding ability factor. During grinding process, sound signals are obtained concurrently by an omnidirectional capacitance microphone. Fast Fourier Transform (FFT) and Discrete Wavelet Decomposition (DWD) are conducted to separate the belt-condition-related sound signals from the raw signals. Then sound features are extracted to establish a novel data-driven model using Optimally Pruned Extreme Learning Machine (OP-ELM). The model is developed to predict the belt grinding ability factor. Experimental datasets are used to train and validate the established model. The results show that the grinding sound in high frequency region from 10 to 15 kHz is sensitive to the belt wear conditions, and that the OP-ELM model speedily and accurately predicts the belt grinding ability factor after optimizing the hidden layer numbers and kernel function type. Compared with experimental results, the mean absolute percentage errors (MAPE) of the predicted grinding ability factor are less than 0.4% and the maximum absolute percentage errors (MAXE) are within 14%. It is thus concluded that the proposed sound-based monitoring approach using the OP-ELM model is robust in accurately predicting the grinding belt condition despite grinding dynamics involving contact pressures. [ABSTRACT FROM AUTHOR]

We establish a vulnerability analytical framework of CISN, and illustrate the impact path of economic fluctuation on CISN performance. Based on this, we propose an improved cascading failure model with directed weighted network, and design five network performance indicators (i.e., relative value of cascading failure, average path length, relative value of maximal connected sub-graphs, network efficiency, and structure entropy). Taking three coal eco-industrial parks in China as cases, we simulate and compare the impacts on CISN vulnerability (i.e., equality-based, dependent-based, and nested-based CISNs) of economic fluctuation. The results indicate that the interaction between economic fluctuation and network structure is the key factor in determining system vulnerability. Concerning overall vulnerability, equality-based CISN is highest, dependent-based CISN is next, and nested-based CISN is lowest. Regarding disturbance type, the changes in the five performance indicators of the three types of CISN are more intense under energy price shocks than with declining demand. Moreover, the cascading failure scale of equality-based CISN is greatest with declining demand, while the other two kinds of CISN’s is greatest under energy price shocks. Concerning disturbance intensity, equality-based CISN shows initial value sensitivity to economic fluctuation, and nested-based CISN has the strongest tolerances for economic fluctuation. From the network performance perspective, the performance of nested-based CISN is superior to that of dependent-based and equality-based CISNs. Due to longer average path length and lower network efficiency, the failure diffusion trend of equality-based CISN shows the curve of Type-S, and the diffusion rate is smooth and slow. Contrariwise, the initial diffusion rate of dependent-based CISN is the highest, indicating that the loss of system efficiency can somewhat improve the system’s anti-risk ability. [ABSTRACT FROM AUTHOR]

Pt nanoparticles are the most frequently used catalyst for Si photocathode. Alternative catalyst based on transition metal or metal oxide as cathode catalyst is greatly desired to replace Pt. A mesoporous α-Fe 2 O 3 thin film (80 nm) was deposited on the surface of planar p-Si using a facile atmospheric pressure chemical vapor deposition (APCVD) method through pyrolysis of ferrocene. The planar Si photocathode shows a 400% enhancement in photocurrent at −1.0 V RHE and an anodic onset potential shift of 0.5 V upon deposition of surface mesoporous α-Fe 2 O 3 layer. This composite photoelectrode also shows superior photoelectrochemical performance to the Pt/planar Si photoelectrode. [ABSTRACT FROM AUTHOR]

With the increasing of frequency and destructiveness of product-harm events, study on enterprise crisis management becomes essentially important, but little literature thoroughly explores the risk prediction method of product-harm event. In this study, an initial index system for risk prediction was built based on the analysis of the key drivers of the product-harm event's evolution; ultimately, nine risk-forecasting indexes were obtained using rough set attribute reduction. With the four indexes of cumulative abnormal returns as the input, fuzzy clustering was used to classify the risk level of a product-harm event into four grades. In order to control the uncertainty and instability of single classifiers in risk prediction, multiple classifier fusion was introduced and combined with self-organising data mining (SODM). Further, an SODM-based multiple classifier fusion (SB-MCF) model was presented for the risk prediction related to a product-harm event. The experimental results based on 165 Chinese listed companies indicated that the SB-MCF model improved the average predictive accuracy and reduced variation degree simultaneously. The statistical analysis demonstrated that the SB-MCF model significantly outperformed six widely used single classification models (e.g. neural networks, support vector machine, and case-based reasoning) and other six commonly used multiple classifier fusion methods (e.g. majority voting, Bayesian method, and genetic algorithm). [ABSTRACT FROM AUTHOR]

Well dispersed Ni and Cu–Ni alloy nanoparticles (∼7 nm) embedded in nanosheets of hierarchical SiO 2 hollow spheres (surface area > 400 m 2 /g) have been synthesized through a hydrothermal process and have shown superior catalytic performance in methane dry reforming (DRM) reaction to the impregnated control sample based on SiO 2 nanospheres. The catalytic activity and the sintering and coke resistant properties of the hierarchical composite catalysts in the high temperature DRM catalysis are ascribed to the strong metal–support interaction and the well dispersed small metal nanoparticles. [ABSTRACT FROM AUTHOR]

In order to enhance the sensitivity of a Fabry–Perot (F-P) acoustic sensor without the need of fabricating complicated structures of the acoustic-sensitive diaphragm, a mini-type external sound pressure amplification structure (SPAS) with double 10 μm thickness E-shaped diaphragms of different sizes interconnected with a 5 mm length tapered circular rod was developed based on the acoustic sensitive mechanism of the ossicular chain in the human middle ear. The influence of thickness and Young's modulus of the two diaphragms with the diameters of 15 mm and 3 mm, respectively, on the amplification ratio and frequency response were investigated via COMSOL acoustic field simulation, thereby confirming the dominated effect. Then, three kinds of dual-diaphragm schemes relating to steel and thermoplastic polyurethanes (TPU) materials were introduced to fabricate the corresponding SPASs. The acoustic test showed that the first scheme achieved a high resonant response frequency with lower acoustic amplification due to strong equivalent stiffness; in contrast, the second scheme offered a high acoustic amplification but reduced frequency range. As a result of sensitivity enhancement, adapted with the steel/TPU diaphragm structure, an optical fiber Fabry–Perot sensor using a multilayer graphene diaphragm with a diameter of 125 μm demonstrated a remarkable sensitivity of 565.3 mV/Pa @1.2 kHz due to the amplification ratio of up to ~29.9 in the range of 0.2–2.3 kHz, which can be further improved by miniaturizing structure dimension, along with the use of microstructure packaging technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • ATP modulated nickel nanowires/graphene aerogel was prepared. • Effective absorption bandwidth can be up to 6.8 GHz at 2.5 mm. • Magnetic nickel nanowire is like a thorny rose-like stalk. While bringing convenience to our life, the extensive use of electromagnetic waves also does harm to the environment and human health. It is crucial to develop electromagnetic wave absorption materials (EAMs) which can solve these problems. However, the developed EAMs cannot meet the increasing requirement well. Here, a novel attapulgite modulated thorny nickel nanowires/graphene aerogel was fabricated by a simple one-pot solvothermal method and freeze drying process. Among all synthesized samples, the minimum reflection loss is −47 dB and the widest effective absorption bandwidth is 6.80 GHz, which is the result of great impedance matching and strong attenuation capability. Attapulgite effectively regulates the electromagnetic parameters, and multiple components provide multiple ways to absorb electromagnetic waves. Our results may help to further design cost-effective EAMs which exhibit excellent absorption performance and broaden the application fields of attapulgite clay minerals. [ABSTRACT FROM AUTHOR]

Refilled friction stir spot welding is proposed to replace friction stir spot welding to solve the problem of keyhole in joining of light metals. However, it is rather challenging to ensure the mechanical property of refilled friction stir spot welding joints because of hook defect. In this study, a novel method was proposed to use graphene nanosheets to strengthen the tip of hook defect and improve overall mechanical properties of joint. The joints of AA2014 aluminum alloy with 0.6%wt graphene nanosheets were fabricated by refilled friction stir spot welding. The results show that the tensile/shear strength of joint increases by 31% and the fracture toughness also is improved by nearly 20% with graphene nanosheets. Extension in fatigue life was achieved on joint with graphene nanosheets. Microstructural observations, fracture characteristics and electron back scattered diffraction analysis were systematically investigated to clarify the mechanism for improvement of strength and toughness. The synergetic effect including grain refinement, load transfer, dislocation strengthening and crack bridging, caused by graphene nanosheets, leads to hardening behavior of graphene nanosheets pinned zone and a significant crack deflection during fracture process, which contributes greatly to improving strength and toughness of joint. Image 1 • An innovative method is proposed to improve overall strength and fatigue life of refilled friction stir spot welding joint through using graphene nanosheets to strengthen the tip of hook defect. • High strength and pinning effect of graphene nanosheets can contribute to strengthening of the tip of hook defect. • Crack deflection and bridging mechanism provided by the robust C–Al interface can be effective to improve toughness of joint. [ABSTRACT FROM AUTHOR]

Surface corrosion resistance of nickel-based superalloys after grinding is an important consideration to ensure the service performance. In this work, robotic belt grinding is adopted because it offers controllable material processing by dynamically controlling process parameters and tool-workpiece contact state. Surface corrosion behavior of Inconel 718 after robotic belt grinding was investigated by electrochemical testing in 3.5 wt % NaCl solution at room temperature. Specimens were characterized by morphology, surface roughness and residual stress systematically. The potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) analysis indicate the corrosion resistance of the specimen surface improves remarkably with the decrease of abrasive particle size. It can be attributed to the change of surface roughness and residual stress. The energy dispersive X-ray spectroscopy (EDS) indicates that niobium (Nb) is preferentially attacked in the corrosion process. A plausible electrochemical dissolution behavior for Inconel 718 processed by robotic belt grinding is proposed. This study is of significance for achieving desired corrosion property of work surface by optimizing grinding process parameters. [ABSTRACT FROM AUTHOR]