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Cross-regional air pollutant spillovers aggravate air pollution in China. To mitigate air pollution, identifying and monitoring air pollution spreaders (APS) is a vital strategy that helps locate the source of air pollution and guides the Joint Prevention and Control of Air Pollution. In this paper, we define an APS as a city with a high spillover impact (CHSI) of air pollution and propose a transfer entropy network to investigate the APS from a multi-timescale analysis perspective. Taking the time series of PM2.5 concentration of 358 Chinese cities from 1 January 2015 to 31 December 2020 as the sample, they are decomposed into short, medium, and long timescales, corresponding to an average period of 12, 111, and 530 days, respectively. Then, we use transfer entropy networks to analyze APS’s spatial distribution and temporal variation patterns on each timescale. The results demonstrate that air pollution spillover widely exists in Chinese cities, and the short-term air pollution spillover dominates all spillovers. The CHSIs form large agglomeration areas in Central and East China on short and medium timescales, while the results of the undecomposed data show a more discrete distribution. In addition, the cities’ air pollution spillover impact is usually high in winter and spring and low in summer. Moreover, the spillover impacts of half of the cities have a lead-lag relationship between short and medium timescales. All results suggest that combining short-term controls and longer-term strategies helps China mitigate air pollution and develop sustainably.

A risk assessment for storm surge disasters can provide scientific support for coastal management as well as marine disaster prevention and mitigation. By taking the Wenchang City of Hainan Province as a pilot area, a risk assessment approach for typhoon-induced storm surge disasters is introduced in detail in this article. First, a numerical simulation system for storm surge inundation is developed, which is applied for the simulation and calculation of the probable maximum storm surge in Wenchang, and the obtained inundation areas and depths are used to assess the storm surge hazard. Then, the data of land use and disaster-bearing bodies are used to classify and assess the vulnerability of Wenchang. Finally, by taking the community as unit, the risk assessment for typhoon-induced storm surge affecting Wenchang is performed by combining the assessment results of both hazard and vulnerability, thereby obtaining a level map of risk distribution. The results show that there are risks of typhoon-induced storm surge in most of the coastal areas of Wenchang, especially for its northeast and east coastal areas, where the risks reach Levels I–II. This approach can be conveniently applied to risk assessments of storm surge in other coastal areas. Note that this approach focuses on the current risk of typhoon-induced storm surge in coastal areas, and further studies will be conducted on the assessment methods for the potential risk.

Duodenal biliary reflux has been a challenging common problem which could cause dreadful complications after biliary stent implantation. A novel anti-reflux biliary stent with a retractable bionic valve was proposed according to the concertina motion characteristics of annelids. A 2D equivalent fluid-structure interaction (FSI) model based on the axial section was established to analyze and evaluate the mechanical performances of the anti-reflux biliary stent. Based on this model, four key parameters (initial shear modulus of material, thickness, pitch, and width) were selected to investigate the influence of design parameters on anti-reflux performance via an orthogonal design to optimize the stent. The results of FSI analysis showed that the retrograde closure ratio of the retractable valve primarily depended on initial shear modulus of material (p < 0.05) but not mainly depended on the thickness, pitch, and width of the valve (p > 0.05). The optimal structure of the valve was finally proposed with a high retrograde closing ratio of 95.89%. The finite element model revealed that the optimized anti-reflux stent possessed improved radial mechanical performance and nearly equal flexibility compared with the ordinary stent without a valve. Both the FSI model and experimental measurement indicated that the newly designed stent had superior anti-reflux performance, effectively preventing the duodenobiliary reflux while enabling the bile to pass smoothly. In addition, the developed 2D equivalent FSI model provides tremendous significance for resolving the fluid-structure coupled problem of evolution solid with large deformation and markedly shortens the calculation time.

Nickel is a strategic mineral resource, with 65% of nickel being used in stainless steel. The situation in Ukraine starting in February 2022 has led to significant fluctuations in nickel prices, with prices of nickel products along the same chain affecting and passing through each other. Using systematic risk entropy and granger causality networks, we measure the volatility risk of trade prices of nickel products using the nickel industry chain trade data from 2000–2019 and explore the transmission patterns of different volatility risk prices from the industry chain perspective. The findings show that: (1) Nickel ore has the highest risk of import trade price volatility and a strong influence, but low risk transmission. Stainless steel has the highest trade price impact but is also subject to the strongest passive influence. (2) The Americas have a higher risk of trade price volatility but a weaker influence. The influence and sensitivity of trade prices is stronger in Asia and Europe. (3) Indonesia’s stainless steel export prices have a high rate of transmission and strong influence. Germany’s ferronickel export prices are highly susceptible to external influences and can continue to spread loudly. Russian nickel ore export prices are able to quickly spread their impact to other regions.

In the context of the economic situation, international relations, and the consequences of COVID-19, the future competition pattern of crude oil trade is uncertain. In this paper, the crude oil international import competition and export competition networks are based on a complex network model. The link prediction method is used to construct a crude oil competition relationship prediction model. We summarize the evolving characteristics of the competitive landscape of the global crude oil trade from 2000 to 2019 and explore the reasons for the changes. Finally, we forecast the future potential crude oil import and export competition. The results indicate the following. (1) The crude oil import competition center is transferred from Europe and America to the Asia–Pacific region and it may continue to shift to developing regions. (2) At present, the competition among traditional crude oil exporters is the core of crude oil export competition, such as OPEC, Canada, and Russia. The United States has become the world’s largest crude oil exporter, which means that the core of crude oil export competition has begun to shift to emerging countries. The competition intensity of emerging crude oil exporters is gradually increasing. There is likely to be fierce export competition between traditional and emerging exporters. (3) In the future crude oil competition, we should pay attention to the trend of the United States, which may lead to the restructuring of the global oil trade pattern. Finally, this paper considers the exporters and importers and puts forward policy suggestions for policymakers to deal with the future global crude oil trade competition.

The synthesis of a novel hierarchical flower-like NiS via a solvothermal method for the electrochemcial oxidation of H2O2 on a carbon paste electrode with high catalytic activity for the (MOR) in an alkaline medium has been reported. Novel nickel sulfide (NiS) hierarchical flower-like structures were characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscopy. A carbon paste electrode was modified with the as-prepared hierarchical flower-like NiS, resulting in a high electrocatalytic activity toward the oxidation of H2O2. The NiS-modified electrode was used for H2O2 sensing, which was achieved over a wide linear range from 0.5 µM to 1.37 mM (I/µA = -0.19025 + 0.06094 C/mM) with a low limit of detection (LOD) of 0.3 µM and a limit of quantitation (LOQ) of 0.8 µM. The hierarchical flower-like NiS also exhibited a high electrocatalytic activity for the methanol oxidation reaction (MOR) in an alkaline medium with a high tolerance toward the catalyst-poisoning species generated during the MOR. The MOR proceeded via the direct electrooxidation of methanol on the oxidized NiS surface layer because the oxidation peak potential of the MOR was more positive than that of the oxidation of NiS. [ABSTRACT FROM AUTHOR]

Abstract: Aiming at overcoming the limitations of the plaster-casting method in traditional prosthetic socket fabrication, the idea of reconstructing the 3D models for bones and skin of the residual limb is proposed. Given the two-dimensional obtained image through CT scanning, using image processing and reverse engineering techniques, the 3D solid model of the residual limb can be successfully reconstructed. The new approach can reproduce both the internal and the external structure of the residual limb. It can moreover avoid making a positive mould by the way of manual modifications. In addition to this, it can provide a scientific basis for the individualization of prosthetic socket design. [Copyright &y& Elsevier]