Biodiesel is a low carbon, renewable, and sustainable fuel, which is a promising alternative fuel used in diesel engines in the future. However, the high viscosity of biodiesel results in poor spray atomization, hindering its ability to fully combustion. Therefore, biodiesel is usually mixed with diesel or oxygen-containing additives to change the physicochemical properties and improve combustion efficiency. In this paper, biodiesel is prepared according to the following mixing mode: (1) diesel is mixed into biodiesel at a ratio of 30% and 50% v/v, and (2) diethyl carbonate is mixed into B30 at a ratio of 10% and 20% v/v. The combustion and emission performance of different blends were compared on a high-pressure common-rail diesel engine that meets current European emission regulations. The test loads consisted of 0.3, 0.6, and 1.0 MPa at 1,600 revolutions/min. The experiment results show that B30DEC20 had the characteristics of low viscosity, high oxygen content, and moderate heating value, and B30DEC20 combined with exhaust gas recirculation (EGR) can achieve more efficient and clean combustion.

Focusing on the Indian subcontinent, a tropical region with ample sunshine, this paper examines the building integrated semitransparent photovoltaic thermal (BiSPVT) system’s viability. The study improves the system’s feasibility by incorporating a thermal mass and water circulation over the panels, which lower the solar cell temperature, reduce thermal gains and room air temperature, and increase solar cell efficiency. Previous studies often overlooked real-time conditions, assuming stable wind conditions. This paper addresses the impact of wind on evaporative cooling and the system’s thermal performance. Unlike earlier research that broadly categorized climates as hot or cold, this research explores six climatic conditions, including moderate and composite climates, and analyzes performance specifically for summer and winter months to provide a comprehensive understanding for effective implementation. The model has proven to be effective, achieving a temperature of 22.03°C under hot and dry conditions in January. For composite conditions during the same month, it reaches 20.68°C, and under cold and sunny climatic conditions in June, it maintains a temperature of 28°C. This effectiveness is a performance-based outcome that reflects the system’s ability to maintain comfortable indoor conditions relative to extreme external weather.

Coal is the second largest global energy source. Accurate identification of tectonic coal is of great significance to many key fields such as coal mining, energy production, and geological research. This paper presents a comprehensive review of tectonic coal identification methods, grounded in an analysis of its classification, genetic mechanisms, and key characteristics. It discusses current identification technologies from both traditional and emerging perspectives and examines their applications in industrial and energy contexts, while identifying key challenges and research gaps. Finally, in view of the shortcomings of the tectonic coal identification method, suggestions are put forward for future research directions, and its future development trends are pointed out from the aspects of multidisciplinary integration, sustainable development, and technological innovation. It highlights underground image recognition as a key area of future development, which holds significant potential for the intelligent identification of tectonic coal and the intelligent prediction of coal and gas outburst.

Reducing Pt usage in proton exchange membrane fuel cells (PEMFCs) is crucial for their widespread adoption. However, lowering Pt loading enhances oxygen transport resistance through ionomer films, negatively affecting performance at high current. Existing mathematical models have struggled to accurately predict this resistance, highlighting the need for a deeper understanding of the underlying mechanisms. This study presents an modified agglomerate model that incorporates a solution-diffusion submodel to better describe oxygen transport behavior under low-Pt loading. The model is validated against experimental data, demonstrating its improved accuracy. Furthermore, the research investigates the impact of electrode structural parameters, including Pt mass fraction, catalyst layer thickness, and ionomer content, on oxygen transport. This work provides new insights into oxygen transport mechanisms in low-Pt catalyst layers, with significant implications for the development of high-performance, low-Pt PEMFCs.

The components and pore structures of shale are complex due to the heterogeneous distribution of organic and inorganic minerals. Understanding the pore structures properties of shale is essential for elucidating the fluid storage and migration mechanisms, which ultimately enhance recovery. This study employs X-ray diffraction to determine the mineral composition of shale. Focused ion beam scanning electron microscope (FIB-SEM) experiments are carried out to analyze the shale components and pore structures. In addition, fractures are described based on micro-computed tomography (CT) scanning techniques. Combining low-temperature nitrogen adsorption and high-pressure mercury injection experiments provides a quantitative description of the micro- and nanoscale pore structures of shale. The results show that clay, quartz, and carbonate content is high in shale samples. Coated, convoluted, and spongy pores exist in organic matter, with fractal dimensions of 1.12, 1.21, and 1.45, respectively. Fractal dimension increases with the maturity of organic matter. Due to complex shale components, the inorganic pores are highly heterogeneous, and the fractal dimensions are distributed in the range of 1.02–1.22. In organic pores, the pore volume in the diameter range of 800–1,200 nm accounts for a large proportion. For clay minerals, pores with diameters less than 100 nm constitute a substantial portion, and the pore volume exhibits a pronounced bimodal distribution. Fracture development is closely related to mineral composition, and the clay minerals restrict the fracture development. In addition, the multiscale pore structures of shale are further analyzed. The pore size of shale exhibits a bimodal distribution. Pores with a diameter of 20–50 nm and fractures with a diameter of about 50 μm occupy a large pore volume. The fractal dimensions of mesopores are distributed in the range of 2.16–2.59, and the fractal dimensions of macropores are distributed in the range of 2.908–2.976.

High-efficiency and energy-saving comprehensive energy systems can provide both economic and environmental benefits. These are crucial for promoting the economy of distribution-network systems. A distributionally robust optimization model is proposed to jointly operate integrated energy systems with wind, hydrogen, cogeneration, combined heat and power (CHP), and other agents, which considers joint demand response and energy sharing across agents. A profit distribution mechanism based on an improved Shapley value is proposed for equally redistributing excessive income. The simulation results show that: (1) the combined wind hydrogen cogeneration-generation (IDR) system reduces hydrogen energy extraction expenses and improves renewable energy utilization efficiency; (2) in line with distributionally robust optimization theory, the optimization model of a wind hydrogen cogeneration direct-drive integrated system for maximizing joint income solves uncertain renewable energy outputs, such as wind energy and photovoltaics, improving the overall benefit of wind hydrogen combined heat and power generation systems; and (3) the improved Shapley value approach solves the income distribution problem for relevant stakeholders, and a reasonable distribution of additional income increases the enthusiasm of all participants.

Coal and gas outburst accidents seriously jeopardize and restrict coal mine safety measures. To effectively reduce the risk of outburst accidents, early warning technology will certainly become a key research topic, which takes the outburst mechanism as theoretical guidance, adopts suitable prediction methods to construct an outburst prediction index, and uses a new generation of information technology to collect and analyze relevant data, predict real-time outburst trends, and apply outburst early warning. This paper analyzes the serious hazards of outburst accidents and summarizes the research on the mechanism of coal and gas outbursts carried out by Chinese and international researchers under different influencing factors. It focuses on the prediction of coal seam outburst danger from two perspectives, local and regional, and analyzes its application effect. This paper provides a systematic summary of current research on four intelligent salient warning techniques based on neural networks, gray theory, data mining, and integrated warning. Combined with the changes in the coal mining industry, it is pointed out that there are deficiencies in the prediction and early warning of coal and gas outbursts: the outburst mechanism is not well understood; the reliability of manual testing of prediction indexes is not high; there is insufficient research on sensitivity; and the intelligence level of early warning technology is low. Given this, its future development is pointed out to provide new technical support for the work of improving gas outburst prediction and prevention.

The mineral composition and content vary greatly in different layers of the clayey silt hydrate-bearing reservoirs in the South China Sea, and the changes in mineral composition and content directly affect the formation and dissociation characteristics of gas hydrates, resulting in differences in electrical characteristics, especially the changes in clay mineral type and content, which have a more significant impact on the hydrate-bearing sediments. In this investigation, the effects of clay mineral types and contents on the synthesis and electrical characteristics of clayey silt hydrate-bearing sediments were studied by simulating the formation and dissociation of gas hydrates. Besides, the microscopic characteristics of gas hydrates were analyzed by high-precision X-ray computed tomography (CT) scanning technology, and the macroscopic electrical behavior mechanism of clayey silt hydrate-bearing sediments containing different clay minerals was revealed. The results show that the formation rate and dissociation rate of montmorillonite silt hydrate-bearing sediments are lower than those of illite silt hydrate-bearing sediments under the same formation and dissociation conditions. Besides, the resistivity of illite silt hydrate-bearing sediments is more significantly affected by gas hydrates. During the process of formation and dissociation, the resistivity of illite silt hydrate-bearing sediments with the same gas hydrate saturation is higher than that of montmorillonite samples.

After a diesel engine is fueled with biodiesel, the morphology and oxidation activity of particulate matter will change, which will affect the performance and regeneration effect of the diesel particle filter (DPF). This article measured the CO2 concentration and regeneration efficiency during the DPF regeneration process under different biodiesel blending ratios, carbon load, heating rates, gas flow rates, and ash content by building a regeneration burner test bench and explored the influence of different regeneration conditions on the oxidation characteristics of biodiesel particulate matter. The results showed that with the increase of biodiesel blending ratio, carbon load, heating rate, and ash content, the CO2 concentration increased and the regeneration efficiency was improved. Notably, when using pure biodiesel, the regeneration efficiency can reach up to 94%. Thermogravimetric analysis showed that under different regeneration conditions, the particle oxidation activity did not change significantly when the regeneration temperature was between 300°C and 400°C, but the activity changed significantly at 500°C. Increasing carbon loading, heating rate, gas flow rate, and ash content to some extent helped improve oxidation activity. Scanning electron microscopy analysis revealed that an increase in biodiesel blending ratio leads to a decrease in particle size and an increase in quantity, and the particles become finer during oxidation, with an increase in porosity and internal voids.