With the increasing demand for energy conservation and emissions reduction in the shipping industry, suctionbased turbine sails have emerged as a novel wind energy utilization technology and have become a research hotspot. This study focuses on the aerodynamic performance of suction-based turbine sails with the aim of investigating the effects of suction intensity and suction port position on their aerodynamic characteristics. By employing Computational Fluid Dynamics (CFD) numerical simulations using the Re-Normalization Group (RNG) k–ε turbulence model and the SIMPLE algorithm, this study provides a detailed analysis of lift and drag coefficients, pressure distribution, and vorticity distribution under various combinations of suction intensity (γ) and suction port position (α). The results show that variations in suction intensity significantly affect the lift and drag characteristics of the turbine sail, while changes in the suction port position directly influence the attachment and separation behavior of airflow on the sail surface. Furthermore, a synergistic effect is observed between γ and α—their interaction not only alters the flow distribution but also plays a critical role in determining the overall performance of the turbine sail.By comprehensively considering the influence of these two factors, the study draws key conclusions for optimizing the design of suction-based turbine sail, providing valuable theoretical insights and technical guidance for their practical application in wind-assisted marine propulsion.

The escalating impacts of climate change are compelling individuals to flee their homes, giving rise to a new category of refugees known as climate refugees. Despite clear evidence linking climate change to forced migration, the protection of these refugees’ human rights remains unaddressed by any existing international legal framework. This paper explores the necessity of embracing a new comprehensive international legal framework tailored to climate refugees. It advocates for a legal framework that addresses prevention and remedies the issues faced by climate refugees and ensures their human rights are safeguarded. We also argued that the Comprehensive International Legal Framework should have a collective obligation to safeguard the rights of climate refugees on the global scale and to provide a solution that integrates the various rules of law, meets humanitarian needs, and is tailored to the protection of the rights of climate refugees.

Sodium sulfate, as a commonly used early strengthening agent, has been widely used in different areas. Because of its sulfonic acid group, sodium sulfate is also used as a cement capillary crystal waterproof material. However, temperature has a significant effect on concrete mixed with sodium sulfate. The effect of sodium sulfate on the early hydration rate at different temperatures was studied by conducting a time and hydration thermal analysis. The effects of sodium sulfate on the mechanical properties of concrete at different temperatures were studied through compressive strength experiments. Impermeability at different temperatures was studied by testing resistance to chloride ion penetration and resistance to water penetration. The effect of resistance to sulfate attack was also experimentally. The hydration products were analyzed by electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The experimental results showed that at low temperature, sodium sulfate can accelerate the early hydration reaction rate, and the effect becomes weaker with increasing temperature. At low temperature, the addition of sodium sulfate can effectively improve the degree of hydration, and enhance the permeability resistance and ion erosion resistance of the matrix.

This study investigated the growth dynamics of Lilium miquelianum bulb scales cultured in four different media formulations: Full Murashige-Skoog (FMS), Half Murashige-Skoog (HMS), Anderson Vitamin (AV), and Knudson Vitamin (KV). Bulb scales were collected from native populations on Jeju Island, Korea, and cultured in vitro for 12 weeks. Growth parameters, including bulb area and scale count, were measured at 3-week intervals. Statistical analyses revealed significant differences in growth rates across media types and time points. FMS consistently demonstrated the highest growth rates and final bulb area and scale count, while KV exhibited the lowest performance. Heatmap analysis showed that FMS achieved the highest weekly growth rates in most time points, with HMS showing comparable performance during early growth stages. Individual sample growth rates varied within media, highlighting the influence of both external and internal factors on growth. Correlation analysis revealed a positive association between bulb size and scale quantity, with FMS exhibiting the strongest relationship. These findings emphasize the importance of appropriate media selection for optimal L. miquelianum propagation, with FMS being the most suitable for extended cultivation. This research provides valuable insights for improving propagation efficiency and conservation efforts of L. miquelianum.

In response to the escalating demands of global trade and the pressing imperative for environmental preservation, the shipping industry is confronted with the dual challenges of augmenting energy efficiency and significantly curtailing carbon emissions. Ship drag reduction technology emerges as a promising solution to address these critical issues. Over the recent years, a spectrum of diverse drag reduction technologies has been developed, each precisely targeting distinct components of ship resistance and influenced by a multitude of factors. We provide a comprehensive synthesis and critical evaluation of the existing literature on ship drag reduction technologies. It categorizes these technologies into four primary domains: body-attached drag reduction, surface drag reduction, air lubrication drag reduction, and other specialized drag reduction techniques. By presenting detailed and extensive experimental data, coupled with real-world application cases, we underscore the practical implementation and proven efficacy of these technologies in reducing ship drag. We delve into the current limitations and challenges encountered by these technologies. We also offer strategic recommendations for future research endeavors and practical applications, aiming to overcome these limitations and enhance the overall performance of drag reduction technologies. The insights provided in this paper aim to serve as a guide for ongoing efforts in developing innovative and effective utilization of ship drag reduction technologies, ultimately contributing to the sustainability and efficiency of the shipping industry.

Research on teaching of Chinese characters has seen a relatively late start in international Chinese language education. Since there is little experience in teaching handwritten characters in previous Chinese as a foreign language instruction, the theory and practice of Chinese character teaching for non-native speakers have developed gradually. The latest Chinese Proficiency Grading Standards for International Chinese Language Education list the Handwritten Chinese Character List as a separate item, strengthening the guiding position of the separation of character recognition and writing principle in teaching Chinese characters. It also allows us to re-examine the issue of handwritten instruction in teaching Chinese characters to those learning Chinese as a foreign language. This paper examines issues in Chinese character teaching based on the theory of Chinese character formation, focusing on three levels of mastery: whole character, component, and stroke. The component teaching method has gained a high level of attention in recent pedagogical circles, and this method offers both advantages and disadvantages. Stroke instruction, often overlooked, is also essential for mastering handwritten Chinese characters. Stroke instruction goes beyond merely practicing basic strokes and their order and emphasizes understanding of the logic behind stroke writing.

Crystalline heptazine carbon nitride (HCN) is an ideal photocatalyst for photocatalytic ammonia synthesis. However, the limited response to visible light has hindered its further development. As a noble metal, Au nanoparticles (NPs) can enhance the light absorption capability of photocatalysts by the surface plasmon resonance (SPR) effect. Therefore, a series of Au NPs-loaded crystalline carbon nitride materials (AH) were prepared for photocatalytic nitrogen fixation. The results showed that the AH displayed significantly improved light absorption and decreased recombination rate of photo-generated carriers owing to the introduction of Au NPs. The optimal 2AH (loaded with 2 wt% Au) sample demonstrated the best photocatalytic performance for ammonia production with a yield of 70.3 μmol g− 1 h− 1, which outperformed that of HCN. This can be attributed to the SPR effect of Au NPs and alkali metal of HCN structure. These findings provide a theoretical basis for studying noble metal-enhanced photocatalytic activity for nitrogen fixation and offer new insights into advances in efficient photocatalysts.

Graphitic nitrogen-doped carbon film/nanoparticle composite, in which the films were wrapped and separated by the nanoparticles, was prepared through a simple co-calcination route. Due to its unique porous structure and improved nitrogen content, the as-prepared electrode material could exhibit high specific capacitances of 317.5 F g− 1 at 0.5 A g− 1 and 200.0 F g− 1 at 20 A g− 1, and stable cycling behavior with no capacitance decline after 10,000 cycles in three-electrode system. When assembled in two-electrode capacitor, its specific capacitance could be well kept at 265.5 F g− 1 at 0.5 A g− 1, and thus the supercapacitor with a high energy density of 9.22 Wh kg− 1 was obtained. The superior energy storage properties of the as-prepared material indicate its promising application as high-performance carbon-based electrode for supercapacitors.

Silicon carbide (β-SiC) was synthesized through an improved sol–gel method, then Ni/SiC catalysts were prepared using a hydrothermal method. The catalysts were characterized using TEM, H2- TPR, CO2- TPD and N2- TPD, etc. The results showed that the synthesized β-SiC had a large specific surface area, promoting the dispersion of Ni species and thus exposing more active sites. The interaction between Ni species and β-SiC contributed significantly to catalytic performance. Furthermore, the strong alkalinity of catalyst could adjust the bond energy of the active metal and N (M–N), which were conducive to desorption of the recombinant N2 from the metal surface, promoting to ammonia decomposition. Among the Ni/SiC catalysts, 30Ni/SiC-700 synthesized with the Ni loading of 30 wt% and calcination temperature of 700 °C, exhibited the optimal ammonia conversion rate of 93.4% at 600 °C under the space speed of 30,000 mL∙gcat −1∙h−1, and demonstrated a long-term stability, suggesting a very promising catalyst in ammonia decomposition.

The economical manufacturing of high-quality graphene has been a significant challenge in its large-scale application. Previously, we used molten Sn and Cu as the heat-transfer agent to produce multilayer graphene on the surface of gas bubbles in a bubble column. However, element Sn and Cu have poor catalytic activity toward methane pyrolysis. To further improve the yield of graphene, we have added active Ni into Sn to construct a Sn–Ni alloy in this work. The results show that Sn–Ni alloy is much more active for methane pyrolysis, and thus more graphene is obtained. However, the graphene product is more defective and thicker because of the faster growth rate. By using 300 ml molten Sn–Ni alloy (70 mm height) and 500 sccm source gas ( CH4:Ar = 1:9), this approach produces graphene with a rate of 0.61 g/hr and a conversion rate of methane to carbon of 37.9% at 1250 ℃ and ambient pressure. The resulting graphene has an average atom layer number of 22, a crumpled structure and good electrical conductivity.

Chlorine is a crucial radionuclide that must be removed in irradiated nuclear graphite. Understanding the interaction between chlorine and graphene-based materials is essential for studying the removal process of 36Cl from irradiated nuclear graphite. In this study, first-principle density functional theory (DFT) was utilized to investigate the adsorption characteristic of chlorine on the original and reconstructed edges of graphene-based materials. Based on the calculation of adsorption energy of the structures after each step of adsorption, the most energetically favorable adsorption routes at four types of edge were determined: Along the armchair edge and reconstructed zigzag edge, the following adatoms would be adsorbed to compensate the distortion induced by the previously adsorbed atom. Meanwhile at the original zigzag edge, chlorine atoms would be adsorbed alternatively along the edge to minimize the repulsion between two adjacent chlorine atoms. The chemical nature of the bonds formed as a result of adsorption was elucidated through an examination of the density of states (DOS) for the two adsorbed chlorine atoms and the carbon atoms attached. Furthermore, to assess the relative stability of the adsorption structures, formation energy of all energetically favorable structures following adsorption was computed. Consequently, the predominant adsorption structure was identified as the reconstructed armchair edge with two chlorine atoms adsorbed. The desorption process of 36Cl2 from the predominant structure following adsorption was simulated, revealing an energy barrier of 1.14 V for desorption. Comparison with experimental results suggests that the chlorine removed from reconstructed armchair edges significantly contributes to the low-temperature removal stage of 36Cl from irradiated nuclear graphite.