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When smelting Al-Li alloy, the material inevitably comes into contact with various oxide-refractories. These refractories are subjected to varying degrees of melt-corrosion at high temperatures. The purpose of this study is to find stable oxide refractories at casting temperature.

Four materials were selected for evaluation, and their corrosion by the Al-Li alloy at casting temperature and different holding times was measured. Subsequently, scanning electron microscopy and energy-dispersive spectroscopy were used to study the interfaces. Stable refractory materials were selected by comparing the thicknesses of the reaction layers.

The thickness of the Al-Li/ZrO₂ reaction layer varies linearly with the square root of the holding duration. Therefore, the growth of the reaction layer is controlled by diffusion. The reaction layer of Al-Li/Al₂O₃ is thinner, and its growth is also controlled by diffusion. However, there were no obvious reaction layers between the Al-Li alloy and MgO or Y₂O₃. By comparing these reaction-layer thicknesses, the order of stability was found to be ZrO₂ < Al₂O₃ < MgO and Y₂O₃.

These results provide a scientific basis for the optimal selection of refractory materials for Al-Li alloy smelting.

The minimum profile problem of a sparse matrix is theoretically treated, and by using the results a new profile reducer is proposed. Numerical experiments clarify that the new reducer is effective for the node re‐ordering of graphs with rather complex configuration. Further considerations on the proposed method and numerical error of the skyline method are also given.

Multiple infectious control measures, e.g. social distancing, city lockdown and mask-wearing, have been implemented since the coronavirus disease 2019 (COVID-19) outbreak. Given the bidirectional relationship between foundational movement skills (FoMS) and physical activity (PA), and inadequate PA in Chinese children and adolescents, FoMS tends to decrease during and after the COVID-19 pandemic. Therefore, the purpose of this paper is to systematically review the literature about the impact of the COVID-19 pandemic on FoMS of individuals aged 5–17 years in Chinese societies.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses was followed. Peer-reviewed articles on four electronic databases (Scopus, Web of Science, EBSCOhost and PubMed) were searched on 8 May 2024. The quality of each study was evaluated by the Mixed Methods Appraisal Tool (MMAT) version 2018. Two independent reviewers were involved in all study selection and appraising procedures.

Among 18,450 records identified, 10 quantitative studies analysing student participants were included. The overall quality of these studies was high, with an average score of 86% in MMAT. The variations among these studies led to inconclusive evaluations. So as to advance the quality of future research and assessments, investigating more aspects of FoMS, standardising physical test protocols and report styles and adopting multiple research designs should be achieved.

To the best of the authors’ knowledge, this is the first review synthesising evidence about FoMS for Chinese children and adolescents. A definitive conclusion cannot be provided due to certain methodological issues. The current situation of FoMS and future research directions were illustrated.

The purpose of this study is to present the state of the art for fiber Bragg grating (FBG) acceleration sensing technologies from two aspects: the principle of the measurement dimension and the principle of the sensing configuration. Some commercial sensors have also been introduced and future work in this field has also been discussed. This paper could provide an important reference for the research community.

This review is to present the state of the art for FBG acceleration sensing technologies from two aspects: the principle of the measurement dimension (one-dimension and multi-dimension) and the principle of the sensing configuration (beam type, radial vibration type, axial vibration type and other composite structures).

The current research on developing FBG acceleration sensors is mainly focused on the sensing method, the construction and design of the elastic structure and the design of a new information detection method. This paper hypothesizes that in the future, the following research trends will be strengthened: common single-mode fiber grating of the low cost and high utilization rate; high sensitivity and strength special fiber grating; multi-core fiber grating for measuring single-parameter multi-dimensional information or multi-parameter information; demodulating equipment of low cost, small volume and high sampling frequency.

The principle of the measurement dimension and principle of the sensing configuration for FBG acceleration sensors have been introduced, which could provide an important reference for the research community.

In this paper the aim is that Aramid/alginate blended nonwoven fabrics were prepared, and the flame retardancy of the blended nonwoven fabrics was studied by thermogravimetric analysis, vertical flame test, limiting oxygen index (LOI) and cone calorimeter test.

The advantages of different fibers can be combined by blending, and the defects may be remedied. The study investigates whether incorporating alginate fibers into aramid fibers can enhance the flame retardancy and reduce the smoke production of prepared aramid/alginate blended nonwoven fabrics.

Thermogravimetric analysis indicated that alginate fibers could effectively inhibit the combustion performance of aramid fibers at a higher temperature zone, leaving more residual chars for heat isolation. And vertical flame test, LOI and cone calorimeter test testified that the incorporation of alginate fibers improved the flame retardancy and fire behaviors. When the ratio of alginate fibers for aramid/alginate blended nonwoven fabrics reached 80%, the incorporation of alginate fibers could notably decreased peak-heat release rate (54%), total heat release (THR) (29%), peak-smoke production rate (93%) and total smoke production (86%). What is more, the lower smoke production rate and lower THR of the blends vastly reduced the risk of secondary injury in fires.

This study proposes to inhibit the flue gas release of aramid fiber and enhance the flame retardant by mixing with alginate fiber, and proposes that alginate fiber can be used as a biological smoke inhibitor, as well as a flame retardant for aramid fiber.

Fabric has complicated anisotropic mechanical behavior because of the woven pattern and complex physical properties. However, most current fabric simulation models are not satisfied because the models are usually geometrical models with stiffness parameters.

In this paper, the authors present a modeling technique to simulate fabric with Riemann manifold. The proposed nonlinear model is formed with ridge wave-curved surface based on the Riemann zero curvature, and the authors develop a solution to conserve the surface area. It decomposes the m × n matrix constituting the fabric into several batches and processes the fabric dots in batches. In this model, the distance between any two adjacent particles of the fabric's is assumed to be equal, and the area of the curved surface is always constant, and the inclination and decay of the ridge wave-curved surface are also considered.

As the result, the simulated shape is lifelike. In time cost performance, the model improves the efficiency of the fabric styling and meets the requirements of real-time simulation.

The proposed nonlinear model is formed with ridge wave-curved surface based on the Riemann zero curvature, and the authors develop a solution to conserve the surface area.

In 2002, Equal Opportunities International published a United States wage and hour law “primer” for foreign companies. That primer provided a basic overview of the U.S. laws regulating the compensation of employees who are working in the United States. On August 23, 2004, one major component of that primer changed: who is exempt from the over time requirements of the Fair Labor Standards Act. This article explains the new Fair Pay Regulations governing which employees may be classified as “exempt” and, consequently, not paid overtime for working more than forty hours in a work week.

Drawing on the resource-based view and institutional theory, this study explores how firms select export channels to realise the value of their product development capabilities (PDC) and improve export performance by aligning PDC, entrepreneurial orientation (EO), cultural-cognitive institutional distance (CCID) and channel selection.

This study adopted a quantitative design and used data collected from multiple respondents in 294 Chinese exporting ventures. Hypotheses were tested using logistic regression analysis and multiple regression analysis.

The results of the study suggest that PDC plays a vital role in export channel decisions. The results also show that there is a three-way interaction between PDC, EO and CCID regarding export channel selection. More importantly, this study suggests that firms using export channels that align with PDC, contingent on EO and CCID, generate superior export performance.

This study extends the export channel literature by looking at the different roles of important organisational capabilities (i.e. PDC and EO) on export channel selection. Further, it shows that firms need to align the exploitation of their PDC with the export channel selection, along with EO capabilities, and CCID to achieve better performance in the export market.

Manufacturing processes, such as laminations, may introduce uncertainties in the magnetic properties of materials used in electrical machines. This issue, together with magnetization errors, can cause serious deterioration in the performance of the machines. Hence, stochastic material models are required for the study of the influences of the material uncertainties. The purpose of this paper is to present a methodology to study the impact of magnetization pattern uncertainties in permanent magnet electric machines.

The impacts of material uncertainties on the performances of an interior permanent magnet (IPM) machine were analyzed using two different robustness metrics (worst-case analysis and statistical study). In addition, two different robust design formulations were applied to robust multi-objective machine design problems.

The computational analyses show that material uncertainties may result in deviations of the machine performances and cause nominal solutions to become non-robust.

In this paper, the authors present stochastic models for the quantification of uncertainties in both ferromagnetic and permanent magnet materials. A robust multi-objective evolutionary algorithm is demonstrated and successfully applied to the robust design optimization of an IPM machine considering manufacturing errors and operational condition changes.

To improve the corrosion resistance of magnesium alloys, the construction of protective coatings is necessary to extend the service life of Mg-based materials.

SiO₂ nanoparticles modified by dodecyltrimethoxysilane (DTMS) were added to the PP and a superhydrophobic Mg(OH)₂/PP-60mSiO₂ composite coating was fabricated on the surface of AZ31 magnesium alloy via the hydrothermal method and subsequently the immersion treatment.

Hydrophilic SiO₂ nanoparticles become hydrophobic after modified by DTMS, showing a higher dispersibility in xylene. By incorporating modified SiO₂ nanoparticles into the composite PP coating, the hydrophobicity of the layer was enhanced, resulting in a contact angle of 166.3° and a sliding angle of 3.4°. It also improved the water repellency and durability of the coating. Furthermore, the intermediate layer of Mg(OH)₂ significantly strengthened the bond between the PP layer and the substrate. The Mg(OH)₂/PP-60mSiO₂ composite coating significantly enhances the corrosion resistance of the magnesium alloy by effectively blocking the infiltration of the corrosion anions during corrosion. The corrosion current density of the Mg(OH)₂/PP-60mSiO₂ composite coating is approximately 8.23 × 10^–9 A·cm^-2, which can achieve a magnitude three times lower than its substrate, making it a promising surface modification for the Mg alloy.

The composite coating effectively and durably enhances the corrosion resistance of magnesium alloys.