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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]

Building resilient cities has become a hot topic in urban planning and risk management. Adopting the perspective of the social‐ecological system (SES), this paper incorporated economy–ecology–society–infrastructure into an integrated research framework and established a system for assessing the urban resilience development level. The entropy weight method was combined with a cloud model to systematically calculate and classify the resilience of 31 provinces (cities) in China. The evaluation results show that (1) the overall level of urban resilience in China was relatively low; the regional analysis showed that (2) the urban resilience of the eastern region was higher than the national average and that of the central and western regions, and from the perspective of the four subsystems, (3) the comprehensive development of each subsystem was the key to improving urban resilience. Finally, five improvement strategies were proposed to provide ideas for enhancing urban SES ability. [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]

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]

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]

For a stock market, a critical problem is the maintenance of its liquidity. Market liquidity can be described in various ways, in particular, in terms of the bid/offer spread and the market depth. A model of market liquidity dynamics has been proposed in the literature. In our study, we improve on this model. On the one hand, we think that trading volume is determined by the total number of traders, as well as the relations between the numbers of buyers and sellers, while the model of Schmidt only considered the first term. On the other hand, Schmidt assumes that the number of ‘newcomers’ in the market is in proportion to the current number of trades. However, we all know that the continual rising or decrease of the price will also attract more buyers or sellers, that is, ‘newcomers’, into the market, which Schmidt has not taken for granted. On the assumption that price variation can be neglected, we discuss the conditions in which chaos will emerge through analysis of the Lyapunov exponent. Finally, we implement a computer simulation of the model in MATLAB, and obtain more interesting results. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]