Journal of Shandong University(Engineering Science)

Multi-scale fusion and dynamic self-calibrating rotation-based catenary dropper detection algorithm

ZHAO Feng, LIU Rui,WANG Ying, CHEN Xiaoqiang, GE Leijiao, MA Aiping

Journal of Shandong University(Engineering Science). 2026, 56(2): 1-10. doi:10.6040/j.issn.1672-3961.0.2025.093

Abstract ( 113 )

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To address the issue of catenary dropper slackness and fractures in high-speed railway contact networks, which severely disrupt train operations, a multi-scale dynamic rotation YOLOv8n(MDR-YOLOv8n)algorithm was proposed to detect the abnormal states of the catenary dropper. High-resolution dropper images were acquired through the high-speed railway contact network 4C inspection system and enhanced via data augmentation. A convolutional local attention version 2(CloAttV2)was designed and integrated into the cross stage partial fusion(C2f)backbone network. Through collaborative axial adaptive pooling and dynamic sparse attention gating, the effectiveness of global-local feature fusion was boosted while the capture capability of key dropper features was enhanced. A lightweight multi-scale dynamic upsampling module with self-calibration mechanism was designed to adaptively adjust sampling weights of the feature maps, effectively utilizing contextual semantic information while reducing model parameters and enhancing anti-interference capability. An oriented bounding box-task align dynamic detection head(OBB-TADDH)was designed, which leveraged task-aligned optimization to enhance rotated object localization, suppress feature redundancy, and improve detection sensitivity for small targets. Experimental results demonstrated that MDR-YOLOv8n achieved 3.7 percentage points improvement in mean average precision at a confidence threshold of 0.5 and 2.3 percentage points increase in inference speed compared to the YOLOv8n model, while maintaining high detection performance under complex environmental conditions. MDR-YOLOv8n optimized the balance among detection accuracy, inference speed, and lightweight design, providing a novel solution for the intelligent upgrade of 4C inspection system.

Evaluation and analysis of unmanned aerial vehicle cluster combat effectiveness based on optimized XGBoost

ZHANG Shuiku, ZHANG Lun, GONG Jianxing, HUANG Jian

Journal of Shandong University(Engineering Science). 2026, 56(2): 11-18. doi:10.6040/j.issn.1672-3961.0.2025.102

Abstract ( 104 )

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To address the huge challenges of high time-sensitivity, behavioral complexity, and massive data volumes in the combat effectiveness evaluation of unmanned aerial vehicle(UAV)cluster, a data-driven effectiveness evaluation method based on the particle swarm optimization(PSO)-extreme gradient boosting(XGBoost)-Shapley additive explanations(SHAP)model was proposed. An effectiveness evaluation model was established using the XGBoost algorithm based on an evaluation index system. The mapping relationship between index data and combat effectiveness was analyzed and verified using simulation data to mine the combat effectiveness of the UAV cluster system. The PSO algorithm was employed to optimize the hyperparameters of the XGBoost model to enhance evaluation accuracy and efficiency. To balance the predictability and interpretability of the evaluation work, the SHAP mechanism was utilized to interpret the effectiveness evaluation process and identify directions for index optimization. Verified by UAV cluster combat simulation data collected via the Vensim platform, the proposed model demonstrated superior accuracy and interpretability compared to support vector regression(SVR), random forest(RF)algorithm, light gradient boosting machine(LightGBM), and back propagation(BP)neural network methods.

Modular-based adaptive weighted federated continual learning method

ZHOU Zhigang, SUN Boyang, DAI Longzheng, BAI Zengliang, MIAO Junzhong

Journal of Shandong University(Engineering Science). 2026, 56(2): 19-34. doi:10.6040/j.issn.1672-3961.0.2025.074

Abstract ( 95 )

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To address the challenges of horizontal and vertical catastrophic forgetting in resource-constrained federated continual learning(FCL)environments, a modular-based adaptive weighted federated continual learning(MAWFCL)method was proposed, which effectively addressed the difficulties of model knowledge retention and task adaptability caused by continuously evolving tasks. Personalized models were constructed by combining composable base parameter modules with adaptive control parameters to achieve adaptation to specific tasks. A module similarity-based reuse mechanism was introduced to enhance the efficiency of knowledge reuse. A parameter capacity-aware precision forgetting strategy was incorporated to prune low-contribution modules and maintain a compact model structure. An adaptive aggregation algorithm based on parameter distance was designed to alleviate knowledge conflicts during global model aggregation. Experimental results showed that MAWFCL method outperformed existing methods in terms of accuracy, catastrophic forgetting mitigation, and communication efficiency. On the CIFAR-100 dataset, MAWFCL method improved test accuracy over federated generative replay learning(FedGReL)and prompt-based dual knowledge transfer(Powder)by 10.93 percentage points and 10.17 percentage points, respectively, demonstrating significant advantages in complex tasks.

Identification of key nodes in complex networks based on the VIKOR-GRA model

ZHANG Shuiwang, YANG Chen, ZONG Qidong, HU Gang

Journal of Shandong University(Engineering Science). 2026, 56(2): 35-42. doi:10.6040/j.issn.1672-3961.0.2024.225

Abstract ( 96 )

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To address the limitations of single-metric approaches and subjective weighting in most traditional methods for identifying critical nodes in complex networks, a novel critical node identification method based on a VIKOR-GRA model(VIKOR-GRA-Key node identification, VGKNI)was proposed. The entropy weight method and grey relational analysis were employed. Building upon the selection of traditional centrality metrics, the bridge centrality metric was introduced. The proposed algorithm was validated using multiple real-world network datasets and was compared with various other methods through comparative analysis. It was demonstrated by the results that the ranking of critical nodes obtained by the proposed method was reasonable, and that superior monotonicity and simulation recovery effects were shown compared to some traditional methods. Therefore, advantages in handling the problem of identifying critical nodes in complex networks were offered by the method presented in this paper, and a new perspective and approach for complex network research were provided.

A logic synthesis delay predicting method based on LSTM

WANG Qingkang, ZHOU Ranran, WANG Yong

Journal of Shandong University(Engineering Science). 2026, 56(2): 43-51. doi:10.6040/j.issn.1672-3961.0.2025.057

Abstract ( 92 )

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To improve the prediction accuracy and efficiency for logic synthesis in digital integrated circuit design process, a logic synthesis delay predicting method based on long short-term memory(LSTM)was proposed. The timing path was treated as an ordered sequence of standard cells, and key feature parameters such as cell type, fanout, load capacitance, and input transition time were extracted and organized into structured sequence data. With the context memory capability of LSTM-based timing modeling, the complex timing dependencies between cells at different levels in the path were captured, achieving high-precision prediction of path delay. Experimental results showed that, compared to existing machine learning-based estimation methods that accumulate cell delays and wire delays, the LSTM-based prediction method demonstrated better adaptability to different types of cases while maintaining accuracy. In terms of running speed, a speedup of 2.8 to 3.2 times was achieved in most test cases. The prediction method was also validated on generic netlists without technology information and the performance was superior to traditional static timing analysis methods, demonstrating its effectiveness and potential for early-stage design applications.

Lightweight SAR ship detection algorithm based on asymptotic feature fusion

LIU Feiyu, ZHANG Jing, WANG Yinan

Journal of Shandong University(Engineering Science). 2026, 56(2): 52-59. doi:10.6040/j.issn.1672-3961.0.2025.099

Abstract ( 115 )

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To address the limitations of restricted receptive fields, inefficient multi-scale feature fusion, and high computational complexity in existing synthetic aperture radar(SAR)ship detection models, a channel-aggregated feature pyramid network(CA-FPN)was proposed. At the feature pyramid architecture level, a cross-level dynamically weighted feature fusion mechanism was introduced. This mechanism adaptively calibrated multi-resolution features using learnable channel attention weights, which overcame the fixed sampling constraints of the traditional asymptotic feature pyramid network(AFPN)and significantly enhanced multi-scale target representation. In designing the feature extraction unit, a parallel multi-scale dilated convolution block(PDBlock)was developed. By integrating the squeeze-and-excitation(SE)channel attention mechanism with dilated convolution techniques, and employing a feature channel aggregation gating mechanism, the PDBlock effectively mitigated semantic conflicts during multi-scale feature fusion. Experimental evaluations on the standard SSDD and LS-SSDD datasets demonstrated that, compared to the baseline AFPN model, CA-FPN maintained detection accuracy while reducing model parameters from 1.93×10⁶ to 1.17×10⁶(a 39% reduction)and computational complexity(in G_FLOPs)from 4.24 to 3.19(a 24% reduction). The mean average precision increased by 2.8% on SSDD and 3.5% on LS-SSDD. CA-FPN was more effective and better adapted to the requirements of SAR ship target detection tasks.

Model test study on the influence of advance support on tunnel surrounding rock stress

MENG Haoran, LI Yao, CHEN Houxian, LI Lin, DU Xuchao

Journal of Shandong University(Engineering Science). 2026, 56(2): 60-75. doi:10.6040/j.issn.1672-3961.0.2025.180

Abstract ( 76 )

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To address the issue of stress redistribution in the surrounding rock during the construction of shallow, large-section loess tunnels, the stress redistribution patterns under three conditions—no advance support, advance small pipes, and advance pipe umbrella—were investigated through model testing and numerical simulation. In the experiments, 3D-printed sliding connectors were innovatively employed to simulate three-stage step excavation, and an internal stress monitoring system was established. The results showed that the advance pipe umbrella formed a strong three-dimensional soil arch with considerable longitudinal length and height ahead of the tunnel face. This significantly reduced the stress release rate of the surrounding soil(from 54.9% to 14.3%)and effectively transferred the overburden weight to both sides of the tunnel. At the same time, the expansion of the plastic zone was substantially suppressed(the plastic zone area was reduced by 49.1%), and the extent of the relaxation zone was diminished(the height decreased from 17.5 m to 14.1 m, and the area was reduced from 138 m² to 110 m². Consequently, the self-supporting capacity of the surrounding rock was enhanced, and its pressure characteristics were altered. This study revealed the mechanism by which advance support regulates stress redistribution through the reinforcement of the 3D soil arch effect, providing a theoretical basis for calculating surrounding rock pressure and designing advance support in shallow-buried loess tunnels.

Prediction model of reinforced concrete resistivity based on finite element simulation

JIA Liujian, HU Jie, BIAN Leixiang, XU Zhan, SHI Haotian, WANG Chong, LIU Hailong

Journal of Shandong University(Engineering Science). 2026, 56(2): 76-81. doi:10.6040/j.issn.1672-3961.0.2024.300

Abstract ( 106 )

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In order to accurately analyze the information of underground artificial structures from transient electromagnetic signals and improve the accuracy of inversion imaging, it was necessary to clearly set the initial value of underground artificial medium resistivity to extract its response. Based on the finite element analysis, the resistivity law of reinforced concrete obtained by the four-electrode method was studied, and the influence of reinforced concrete thickness and steel bar spacing on resistivity was revealed. The influence of electrode spacing on the test results was analyzed, and the optimal electrode arrangement method and prediction function model were proposed. The reinforced concrete under different working conditions was prepared and tested. The experimental data were compared with the predicted values and the mean square error was analyzed to verify the advantages of the model.

Numerical simulation of construction control for residual stress in Q355 steel butt welds

ZHANG Heng, ZHENG Yang, SUN Yindong, WU Ke, ZHANG Maoyong, CHANG Hao

Journal of Shandong University(Engineering Science). 2026, 56(2): 82-95. doi:10.6040/j.issn.1672-3961.0.2025.036

Abstract ( 107 )

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Welded connections are widely used in prefabricated steel residential structures, and residual stresses from welding adversely affect structural quality. Welding simulations were conducted using ABAQUS to compare the effectiveness of weld activation methods, including the event sequence method, element birth and death method, and field variable method. The event sequence method was selected to improve computational efficiency, and its accuracy was validated by experiment. The effects of groove shape, post-weld heat treatment(holding temperature and time), and ambient temperature on residual stress in Q355 steel butt welds were investigated. Results showed that U-shaped grooves suppressed residual stress, and the selection of groove shape should consider both stress control and processing cost. Increasing holding temperature and time improved stress relief, with 500 ℃ for 3 hours recommended. Lower ambient temperatures reduced interpass cooling time and improved welding efficiency, while a range of 5-20 ℃ was suggested to ensure welding quality.

The data recovery, extraction and detection methods of acoustic wave detection in complex tunnel construction environments

YE Shengming, WANG Rui, CHEN Long, ZHANG Xiangchao, CHEN Lei, CAO Hongyi

Journal of Shandong University(Engineering Science). 2026, 56(2): 96-111. doi:10.6040/j.issn.1672-3961.0.2025.095

Abstract ( 83 )

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To acquire the detected reflected acoustic waves of unfavorable geology inside the rock mass, sensors needed to be installed on the tunnel sidewalls for seismic wave vibration collection. However, the excavated surface of the tunnel rock mass was uneven, which affected the coupling of sensors and led to distortion in the collection of characteristics such as amplitude and waveform. Meanwhile, strong noise was generated by multiple operating processes including tunnel motors and pump stations, which interfered with the identification and extraction of acoustic wave responses related to unfavorable geology in the tunnel.In response to these issues, a method for detecting unfavorable geology in tunnel construction based on acoustic wave attenuation compensation and denoising was proposed in this research. Focusing on the uneven rock mass surface caused by excavation, the acoustic wave signal characteristics under different coupling forms were revealed through numerical simulation studies, and the dry coupling materials suitable for acoustic wave collection were optimally selected. At the same time, aiming at the energy attenuation of acoustic wave propagation on uneven surfaces, the amplitude attenuation law was analyzed based on measured data. An amplitude attenuation compensation method for acoustic wave transmission on uneven surfaces was constructed based on Butterworth filtering, and the acoustic wave noise suppression method combined with empirical mode decomposition(EMD)and wavelet transform was improved. Through these measures, the identification and extraction of high-resolution acoustic wave reflected wavefields were realized.The above method was successfully verified on the surface of the actual engineering rock mass in front of the roadway of Ezhuang Coal Mine. The test results showed that the quality of acoustic wave signals on the uneven rock surface of the tunnel was improved, which was conducive to identifying the acoustic wave response signals of unfavorable geology and provided guidance for the detection of unfavorable geology in front of the tunnel.

Analytical model and verification of stress calculation for backward immersed pipe in ditch

SHAN Lijie, ZHANG Lisong, YANG Qingchun, LI Longsheng, ZHAO Xinbo

Journal of Shandong University(Engineering Science). 2026, 56(2): 112-120. doi:10.6040/j.issn.1672-3961.0.2025.079

Abstract ( 73 )

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The coupling effect between the pipe and soil was considered during the process of sinking the pipe into the trench. Based on the theory of elastic foundation beams, a stress analysis model for the pipeline under the back sinking pipe into the trench was constructed using the deflection curve equation and deformation coordination conditions. To verify the accuracy of the analytical model, a finite element model considering the plastic constitutive relationship of soil was established with Abaqus for comparative analysis. When the results of the standard model, analytical model, and finite element model were compared on parameters(length of the arch section, length of the suspended section, maximum stress, and bending moment of the pipeline), the errors between the analytical model and the finite element model were found to be 3.58%, 3.50%, 4.89%, and 3.52%, respectively. Meanwhile, the maximum error between the standard model and the finite element model was observed to reach 13.40%.The results showed that during the lowering of the pipeline into the trench, the maximum stress first occurred at the middle position of the immersed tube. After 80 m of excavation, it appeared at the end of the trench excavation. Before contact with the trench bottom was made, three stress concentration points were identified in the pipeline. After contact with the trench bottom was established, four stress concentration points were observed in the pipeline.This modeling method, based on the interaction mechanism, was demonstrated to more accurately characterize the mechanical response characteristics of the pipeline-soil system. From an engineering practice perspective, the model was confirmed to significantly improve the accuracy of pipeline system mechanical analysis. It is considered to hold important engineering application value for ensuring the structural integrity and operational safety of long-distance pipelines.

Low-frequency oscillation suppression method in train-network systems based on sliding mode control structure of onboard rectifiers

TIAN Jiangtao, LI Yanzhe, CHEN Xinzhou, GANG Tiecheng

Journal of Shandong University(Engineering Science). 2026, 56(2): 121-129. doi:10.6040/j.issn.1672-3961.0.2025.042

Abstract ( 90 )

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To address the low-frequency oscillation occurring during the pantograph-raising and preparation phase of high-speed trains, an adaptive sliding mode control(ASMC)strategy was proposed for electric multiple unit(EMU)rectifiers. Using the CRH5 model as the test subject, a return ratio matrix model of the coupled system with the traction network was established. By incorporating an improved sum-norm criterion, the cause and critical conditions of low-frequency oscillation were analyzed. Based on the operational conditions of the EMU during low-frequency oscillation, a state-space model was derived. Adaptive sliding mode controllers were designed for the voltage outer loop and current inner loop to replace conventional linear proportional-integral(PI)controllers. A simulation model of the train-network coupling system was developed in Simulink/MATLAB. Comparative simulations with several traditional control strategies demonstrated that the ASMC approach comprehensively outperformed others in overshoot, settling time, voltage fluctuation, and low-frequency oscillation suppression, exhibiting superior performance and effectively mitigating the low-frequency oscillation phenomenon.

Short-term wind power prediction model based on spatial-temporal graph convolutional network with dual-graph structure

ZHENG Zheming, KONG Lingling, HE Yin

Journal of Shandong University(Engineering Science). 2026, 56(2): 130-138. doi:10.6040/j.issn.1672-3961.0.2025.030

Abstract ( 100 )

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To address the limitations of traditional wind power prediction methods that ignored the interaction of spatial-temporal features, a spatial-temporal graph convolutional network with attention(STGCN-A)was proposed. A correlation matrix was constructed by the maximal information coefficient to form a statistical correlation-based spatial graph, while an Euclidean distance-based geographic proximity spatial graph was built to achieve dual-graph modeling among wind turbines. Spatial features were extracted through a graph convolutional network(GCN), and temporal dependencies were captured by a gated recurrent unit(GRU). An attention mechanism(AM)was introduced to dynamically weight different time steps, enhancing the representation of critical information in spatial-temporal features. Comparative experiments on real wind power datasets demonstrated that the proposed model outperformed traditional methods in terms of root mean square error(E_RMS), mean absolute error(E_MA), and coefficient of determination(R²). The results indicated higher prediction accuracy and strong potential for practical applications.

Design and performance analysis of pumped two-phase cooling system for more electric aircraft thermal management

WU Tao, WANG Lizhi, RONG Yi, ZHANG Xueqin, TANG Yicun

Journal of Shandong University(Engineering Science). 2026, 56(2): 139-146. doi:10.6040/j.issn.1672-3961.0.2024.330

Abstract ( 95 )

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In order to address the heat dissipation problem for high heat flux devices such as electric actuators and electronic equipment on more electric aircraft, in this paper a pumped two-phase cooling system with multiple evaporators in parallel was proposed. Based on the characteristics of the thermal load, the overall design of the cooling system was completed, and the operating performance of the pumped two-phase cooling system was analyzed and evaluated using simulation methods. The results showed that the microchannel evaporators with a channel size of less than 1 mm could effectively cool electronic devices and electric actuators with a heat flux density of more than 40 W/cm². The cooling system exhibited excellent steady-state and dynamic performance and could effectively dissipate up to 40 kW heat load. Under all the operating conditions studied in this paper, the cooling and temperature control requirements were all met.

Analysis of flow and heat transfer characteristics in the novel energy storage battery module with immersion cooling

GUO Junshan, ZHU Lingkai, GONG Zhiqiang, LIANG Kai, ZHONG Ziwei, SHANG Panfeng, WANG Xinyu

Journal of Shandong University(Engineering Science). 2026, 56(2): 147-157. doi:10.6040/j.issn.1672-3961.0.2024.328

Abstract ( 101 )

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To address the limitations of immersion liquid-cooled battery modules, such as limited heat transfer performance and inaccurate internal heat transfer prediction models, a novel immersion liquid-cooled energy storage battery module was proposed. In this work, the flow and heat transfer characteristics of the novel module incorporating an internal baffle were systematically compared with those of traditional immersion modules. The effects of coolant velocity and initial temperature on battery heat transfer performance were comprehensively investigated. Furthermore, a Nusselt number correlation was developed to predict the heat transfer process associated with coolant sweeping across the cells. The results demonstrated that the novel battery module exhibited superior flow and heat transfer performance compared with the traditional immersion module. Increasing the coolant flow rate significantly enhanced the heat transfer capability and temperature uniformity of the module, resulting in a 5.7% reduction in the average battery temperature of the high-temperature battery and a 47.6% reduction in the maximum temperature difference within the module. In addition, raising the initial temperature deteriorated the heat transfer performance but improved the module temperature uniformity, which increased the average battery temperature by 28.2% and decreased the temperature difference by 59.5%. Within the specified range, the proposed correlation predicted the heat transfer behavior with an average relative error of 2.0% compared with numerical simulation results, indicating high accuracy in characterizing the heat transfer performance of the novel module.

Roll bond aluminum flat loop heat pipe for high-temperature strong cooling air-conditioner

WANG Dingyuan, GUO Zhongchang, LI Yong, PEI Yuzhe, ZHAO Pengda, ZHANG Chuanmei, WANG Weifeng, CHANG Lihua, WANG Fei, LUO Rongbang

Journal of Shandong University(Engineering Science). 2026, 56(2): 158-165. doi:10.6040/j.issn.1672-3961.0.2024.331

Abstract ( 66 )

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In order to solve the high-temperature heat dissipation problem of inverter power devices in air conditioner outdoor units, this paper proposed and developed a novel pump-free roll bond aluminum flat-plate loop heat pipe and radiator.Thermal simulation and experimental investigations were carried out on a cabinet air conditioner with rated cooling capacity of 7 600 W, thereby effectively resolving the high-temperature heat dissipation issue of inverter power devices under air-forced cooling conditions.The prototype air conditioner achieved 100% of its rated refrigerating capacity when the ambient temperature of the outdoor unit reached 53 ℃, and was capable of continuous operation even at an outdoor ambient temperature of 62 ℃. This performance enabled the air conditioner to adapt well to the extreme high-temperature weather in summer.

Experimental study on start-up and heat transfer characteristics of C-shaped pulsating heat pipe

LI Xinze, HONG Rui, DU Wenjing

Journal of Shandong University(Engineering Science). 2026, 56(2): 166-174. doi:10.6040/j.issn.1672-3961.0.2024.326

Abstract ( 91 )

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The heat transfer performance of a C-shaped pulsating heat pipe(PHP)was experimentally investigated using acetone, absolute ethanol, deionized water, methanol, and an acetone-methanol mixture as working fluids. The experiments were conducted under varying heating powers(ranging from 30 W to 270 W)and filling ratios(ranging from 30% to 80%). The results indicated that within the experimental parameter range, the C-shaped PHP exhibited excellent flow pattern transition speed and startup performance when acetone and methanol were used as working fluids. The thermal resistance generally showed a decreasing trend with the increase in heating power; however, the improvement of thermal resistance by power increment exhibited a significant marginal effect. Thermal resistance demonstrated obvious filling ratio-dependent characteristics in different power intervals. Thus, the optimal filling ratio of the C-shaped PHP should be selected based on the actual operating power to achieve the best heat transfer effect. In the pre-startup stage of the PHP, the thermal resistance during the power-up process was slightly lower than that during the power-down process. After startup, the thermal resistance during the power-up process became slightly higher than that during the power-down process. This difference was suppressed when the filling ratio increased from 50% to 60%.

Experimental study of heat transfer in manifold microchannel heat sinks

ZHOU Naixiang, XU Jinjin, ZHANG Jingzhi

Journal of Shandong University(Engineering Science). 2026, 56(2): 175-180. doi:10.6040/j.issn.1672-3961.0.2024.332

Abstract ( 83 )

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To study the performance of high heat flux cooling devices, a visual experimental setup for flow and heat transfer in manifold microchannels was built. Experiments were conducted to investigate the heat transfer performance of copper-based microchannels. Using deionized water as the coolant, the heat power was varied from 100 to 400 W. The effects of single-phase and boiling flow on heat transfer were analyzed at coolant flow rates of 120 and 300 mL/min. The bubble growth process was also observed. Results showed that under both single-phase and boiling conditions, the thermal resistance decreased slightly as the heat flux increased. During boiling, bubbles formed along the wall, detached from the bottom, and migrated into the manifold channels. When gas had accumulated sufficiently at the inlet of the manifold, it quickly passed through the microchannels below and exited through the outlet channel, enhancing heat transfer performance.

Comparison on manual and automatic monitoring of greenhouse gases from fixed pollution sources in sewage treatment plants and waste incineration power plants

LIU Tiedong, LIN Na, XIE Tingting, LENG Yaling, YAO Tingting, MA Zhitong, ZHAO Hongxia

Journal of Shandong University(Engineering Science). 2026, 56(2): 181-188. doi:10.6040/j.issn.1672-3961.0.2024.298

Abstract ( 105 )

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In order to solve the monitoring difficulties of greenhouse gas emissions in industries such as sewage treatment plants and municipal waste incineration power plants, break the dependence of monitoring equipment performance indicators on foreign countries, and establish a traceability system for N₂O and CH₄ monitoring equipment, by manual monitoring and portable device, this article analyzed the differences in mass concentration of N₂O and CH₄ emissions through two methods: manual monitoring and portable device measurements. Results showed that, at three different locations in a typical wastewater treatment plant scenario, the differences in average mass concentrations were 8.66, 12.20, 0.75 mg/m³ for N₂O, respectively, and 45.74, 64.30, 214.82 mg/m³ for CH₄ respectively. The two measurement methods showed significant discrepancies. In typical scenarios of power plants, manual monitoring data showed little difference from that of online monitoring, but significant to portable device measurements, which was mainly due to the portable device being susceptible to temperature, humidity and mutual interference between different gases. Research on portable devices in terms of water vapor, high temperature, high humidity, and the coexistence of multiple gases should be strengthened to improve the accuracy of portable devices. Generally, manual monitoring was more accurate and reliable compared to other methods.

Water footprint of major red meat products from a life cycle assessment perspective

LI Mengqing, ZHANG Tianzuo, MA Xiaotian, HONG Jinglan

Journal of Shandong University(Engineering Science). 2026, 56(2): 189-196. doi:10.6040/j.issn.1672-3961.0.2025.050

Abstract ( 64 )

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To address the issues of water consumption and pollution caused by large-scale red meat production, an indigenized water footprint model based on life cycle assessment theory was adopted to systematically quantify and analyze the water footprints of three red meat products: pork, beef, and mutton. The results indicated that, within the “cradle-to-gate” system boundary, pork production had the highest water footprint across most midpoint and endpoint impact categories, followed by beef, while mutton had the lowest. The water footprints of the three types of meat production showed similar patterns in the analysis of key processes, mainly driven by feed production and direct emissions. Directly consumed water and copper discharged to soil were identified as key substances contributing to impacts on human health and ecosystem quality, respectively. The spatiotemporal analysis suggested that restructuring livestock systems, adopting site-specific strategies, and improving feed use efficiency are essential measures to reduce the sector's water footprint.

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