Liaoning Technical University

Xia Y., Zhang F., Wang S., Wei S., Zhang X., Dong W., Shen D., Tang S., Liu F., Chen Y., Yang S.

The study of pore structure regulation methods has always been a central focus in enhancing the capacitance performance of porous carbon electrodes in lithium-ion capacitors (LICs). This study proposes a novel approach for the synergistic regulation of the pore structure in porous carbon using phenol-formaldehyde (PF) resin and boric acid (BA). PF and BA are initially dissolved and adsorbed onto porous carbon, followed by hydrothermal treatment and subsequent heat treatment in a N2 atmosphere to obtain the porous carbon materials. The results reveal that adding BA alone has almost no influence on the pore structure, whereas adding PF alone significantly increases the micropores. Furthermore, the simultaneous addition of PF and BA demonstrates a clear synergistic effect. The CO2 and H2O released during the PF pyrolysis contribute to the development of ultramicropores. At the same time, BA facilitates the N2 activation reaction of carbon, enlarging the small mesopores and aiding their transformation into bottlenecked structures. The resulting porous carbon demonstrates an impressive capacitance of 144 F·g−1 at 1 A·g−1 and a capacity retention of 19.44% at 20 A·g−1. This mechanism of B-catalyzed N2-enhanced mesopore formation provides a new avenue for preparing porous carbon materials. This type of porous carbon exhibits promising potential for applications in Li-S battery cathode materials and as catalyst supports.

Ma F., Qu Q., Yang F., Xu G.

Dong W., Sasaki K., Zhang H., Wang Y., Zhang X., Sugai Y.

Jia K., Chen Y.

With the accelerated advancement of the global technological revolution and industrial transformation, digitalization and greening are increasingly becoming important trends in the transformation and development of the global economy and society, and the deep integration and collaborative development between the two has become the core issue of current scientific exploration. This study examines the influence and underlying mechanisms of data factors on green innovation among Shanghai and Shenzhen A-share manufacturing listed companies in China, spanning from 2013 to 2023. The empirical analysis reveals a positive correlation between data factors and the enhancement of corporate green innovation. A deeper investigation indicates that this positive effect is more pronounced in eastern enterprises and non-state-owned entities. Additionally, data factors facilitate corporate green innovation by augmenting investment in innovation and intensifying external governance factors, such as analyst attention. Based on these empirical findings, this paper advocates for several measures as follows: enhancing the development of the data factor market; fostering research and development in digital technologies; and fostering integration between digital factors and business applications.

Sui X., Liao B., Wang C., Shi Z.

Zhu W., Yang T., Zhang R.

Unmanned Aerial Vehicles (UAVs) are increasingly utilized for bridge inspections and play a crucial role in detecting defects. Nevertheless, accurately identifying defects at various scales in complex contexts remains a significant challenge. To address this issue, we propose RDS-YOLO, an advanced algorithm based on YOLOv8n, designed to enhance small-scale defect detection through the integration of shallow, high-resolution features. The introduction of the RFW (Receptive Field Weighting) module dynamically expands the receptive field and balances multi-scale detection accuracy. Additionally, the DSF-Bottneck (Dilated Separable Fusion) module further optimizes feature extraction, emphasizing the representation of small defects against complex backgrounds. The SA-Head (Shuffle Attentio) module, with shared parameters, precisely localizes defect zones while reducing computational costs. Furthermore, the EigenCAM technique improves the interpretability of the model’s output, offering valuable insights for maintenance and monitoring tasks. The experimental results demonstrate that RDS-YOLO outperforms YOLOv8n, achieving a 3.7% increase in average detection precision and a 6.7% improvement in small defect detection accuracy.

Wen H., Fan C., Zhou L., Yang L., Fu X., Luo M., Shi H., Wang Y., Bai G.

Zhang P., Tang S., Wan D., Li X., Ai P., Guo W., Yan T., Zhang Y., Li Q., Bai S.

Wang Z., Topal E., Shao L., Yang C.

Xie L., Li X., Bao L., Zhang Y., Su H., Liu X., Wang F., Wei Y., Ji N., Zhou M.

Dieldrin is legacy organochlorine insecticide, which was listed in the Stockholm Convention because of its persistence, bioaccumulation and toxicity. However, it is still present in the environment and in organisms two decades after its ban. The current criteria used for risk assessment in China are based on acute toxicity data in water columns without considering the bioavailability and bioaccumulation, which accordingly lead to the under-protection of aquatic organisms and wildlife. In this study, the water quality criteria (WQC) for dieldrin were derived from a combination of tissue-based toxicity data and the bioaccumulation factor (BAF) to better protect aquatic ecosystems. The dieldrin residue data in surface water in China were obtained by literature review and the ecological risk was assessed using the quotient method. Combined with a BAF of 58,884.37 L/kg estimated by the model, the WQC were calculated as needing to be 3.86 and 1.4 ng/L to protect aquatic life and aquatic-dependent wildlife, respectively. The results of the risk assessment revealed the potential high risk posed by dieldrin bioaccumulation. This study provides scientific guidance for the determination of the water quality standard for dieldrin and to ensure the risk management of the aquatic environment in China.

Wang D., Wu Y., Yin L.

Targeting the concern that nearby inflexible buildings may be at risk for safety issues due to the surface deformation caused by foundation pit excavation disruptions, this paper took the large-scale foundation pit in the Hongshaquan second mine stope in Xinjiang as the research backdrop. To examine the deformation mechanism, generic numerical simulation models were built with varying excavation depths. The unloading effect of foundation pit excavation was addressed using the Fourier integral approach, which is based on elastic theory. An elastic theoretical analytical approach for the surrounding deformation during disturbances due to the excavation of foundation pits was derived by superimposing the unloading impact of the surrounding soil and including pertinent boundary conditions. By contrasting the outcomes of the numerical simulation with the theoretical analysis and the real on-site monitoring data, the accuracy of this approach was confirmed. The findings indicated that the deformation of the surrounding ground surface rises as the excavation depth grows during the foundation pit excavation process in open-pit mines. The deformation decreases with increasing distance from the slope crest to the monitoring location. The deformation of the surrounding ground surface reduces as the rock and soil mass’s elastic modulus and Poisson’s ratio rise. However, the deformation of the surrounding ground surface increases as the excavation depth and slope angle rise. This study offers fresh ideas and approaches for examining how the surrounding ground surface deforms while a foundation hole is excavated.

Gao K., Ma S.

With the popularization of comprehensive mechanized mining methods and the increase in coal mining intensity, production has become more concentrated and efficient, which inevitably leads to Coal seam accumulates a large amount of gas The existence of huge goaf and mining overburden cracks that form behind the working face provides favorable conditions for the migration of gas to the goaf and its subsequent accumulation. The high concentration of gas that accumulates in the goaf gradually flows toward the working face under the action of pressure and concentration gradients, which can easily cause gas overrun accidents at the working face. Therefore, effective relief of the gas pressure in the goaf is important to guarantee safe and efficient mining at the coal mine working face. One of the most used gas drainage methods in such mines is high-level borehole gas drainage. This method can effectively reduce the gas content of coal seams, ensure the safe production of working faces, and reduce carbon emissions. In this study, the mining of a high-gas and low-permeability extra-thick coal seam in the Shanxi mining area is taken as the engineering background. In order to optimize the extraction design and improve the efficiency of gas extraction, according to the dual characteristics of coal seam pores and cracks, the permeability, and migration form of the gas in the coal body are analyzed, and a COMSOL coal seam gas migration model is established. By controlling different gas extraction horizons, pressure, and the number of boreholes and by optimizing the trajectory of the boreholes, the law of gas migration during high-level borehole gas extraction and the variation law with extraction time and pressure are studied. From this, the effective extraction calculation formula is fitted and statistical analyses are carried out. Through on-site extraction and simulation verification, the gas concentration was found to reach a maximum of 86% at a distance of 23 m from the floor. When using similar extraction times, 20 MPa gas extraction was found to have the best effect. The highest gas concentration in the upper corner was only 0.71%, and the extraction efficiency is higher when the high-level borehole trajectory angle is 30 degrees. The research results have important reference value for gas disaster control in the fully mechanized caving face of high-gas low-permeability and extra-thick coal seams.

Xiao J., Zhang X., Wang Z.

Cheng L., Zhao L., Cheng L., Gao Y., Guo H., Che Y., Fu H.

Coal gangue (CG) is one of the most frequent solid wastes in the world, and it poses a severe hazard to both human society and natural ecosystems. In light of the progressive increase in environmental awareness and the unavoidable trend of the requirements of a sustainable development plan, how to efficiently use these vast quantities of CG has become an important subject in China. Concrete aggregate, which can not only solve environmental pollution but also compensate for the scarcity of natural gravel and sand resources, is the most cost-effective and eco-friendly way to utilize CG resources in accordance with the strategic requirements of green and sustainable development. However, how to deal with the preparation of high-quality gangue aggregate needs to be targeted research; blindly using gangue for concrete may bring some safety hazards. This requires that based on the source, distribution, storage, chemical composition, mineral composition of the gangue and the problems in the utilization process, efforts are made to open up the key routes of gangue concrete utilization, and to provide theoretical guidance for the high-value and environmentally friendly utilization of the CG. This paper summarizes the CG aggregate characteristics and its impact on concrete performance, discusses the technical means to improve the performance of CG aggregate concrete, and analyzes if the current CG aggregate in the concrete application of the problem still exists, with a view to gradually realize the CG of low-energy consumption bulk utilization. The popularization and application of CG aggregate will accelerate the solution of the environmental pollution problem it brings, and can to a certain extent alleviate the current situation in that the supply of natural sand and gravel resources is insufficient to meet the demand; the sustainable development of today’s research on CG aggregate for concrete has important environmental and economic significance.

Wang D., Yan H., Qi C., Lu S., Li B.

To improve the quality of trench, backfill projects, this study utilizes solid waste to prepare a controllable low-strength material. Through uniaxial compression, three-point bending tests, and scanning electron microscopy (SEM), the mechanical performance evolution and fiber reinforcement mechanisms of the backfill material are revealed. Based on a two-parameter Weibull distribution probability model, an intrinsic correlation between the number of freeze–thaw cycles, damage variables, and compressive strength is established. The research results indicate that when the NaOH content is 3%, the water-to-solid ratio is 0.4, and the number of freeze–thaw cycles is 0, the sample’s mechanical properties reach their local optimum. After curing for 28 days, a significant amount of amorphous gel-like substance is formed inside the system, filling the intergranular spaces between aeolian sand particles, resulting in a relatively dense structure for the backfill material. In response to the degradation caused by the initial defects in the sample, fibers effectively prevent crack initiation. Based on the stochastic characteristics of freeze–thaw damage, the number of freeze–thaw cycles (n) follows the Weibull distribution model well. Using experimental data, evolution equations for the number of freeze–thaw cycles, intrinsic damage, and compressive strength were developed, ultimately establishing the intrinsic relationship between sample damage and strength. The findings provide theoretical support for addressing trench backfill engineering disasters in seasonally frozen regions.