摘要：
Proactive maintenance is widely recognized for enhancing equipment reliability and reducing downtime costs. However, its role in optimizing spare parts production and distribution decisions remains underexplored, thereby limiting efficient cross-domain resource utilization within the supply-demand system. This paper addresses this gap by studying a maintenance-driven multi-stage joint optimization problem (MMJOP), which integrates flexible spare parts production, multi-vehicle distribution, and imperfect maintenance. We propose an optimal imperfect maintenance strategy to link these cross-domain business activities precisely, and further develop a mathematical model aimed at minimizing energy consumption on the supply side and operational costs on the demand side. To solve the MMJOP, we design an enhanced non-dominated neighbor immune algorithm, featuring a customized initialization operator and a problem-specific local search operator. Additionally, a Q -learning mechanism is employed to automatically select the most appropriate key parameters in the proposed algorithm. Extensive experiments indicate that: (1) the proposed components greatly enhance QNNIA's search performance; and (2) the QNNIA outperforms four well-known comparison algorithms regarding computational optimality, convergence, distribution, and stability. More importantly, the proposed model yields significant economic value, i.e., saving operational costs by 49% with negligible impact on overall energy consumption, proving the necessity of cross-domain business cooperation and resource optimization in the high-end equipment industry.
Proactive maintenance is widely recognized for enhancing equipment reliability and reducing downtime costs. However, its role in optimizing spare parts production and distribution decisions remains underexplored, thereby limiting efficient cross-domain resource utilization within the supply-demand system. This paper addresses this gap by studying a maintenance-driven multi-stage joint optimization problem (MMJOP), which integrates flexible spare parts production, multi-vehicle distribution, and imperfect maintenance. We propose an optimal imperfect maintenance strategy to link these cross-domain business activities precisely, and further develop a mathematical model aimed at minimizing energy consumption on the supply side and operational costs on the demand side. To solve the MMJOP, we design an enhanced non-dominated neighbor immune algorithm, featuring a customized initialization operator and a problem-specific local search operator. Additionally, a Q -learning mechanism is employed to automatically select the most appropriate key parameters in the proposed algorithm. Extensive experiments indicate that: (1) the proposed components greatly enhance QNNIA's search performance; and (2) the QNNIA outperforms four well-known comparison algorithms regarding computational optimality, convergence, distribution, and stability. More importantly, the proposed model yields significant economic value, i.e., saving operational costs by 49% with negligible impact on overall energy consumption, proving the necessity of cross-domain business cooperation and resource optimization in the high-end equipment industry.
摘要：
We propose a simple and effective strategy to improve the high-temperature sensing characteristics of fiber Bragg gratings (FBGs) by introducing compressive stress into the grating structure by means of torsion assisted. Specifically, comparative analysis reveals that the torsion-assisted FBG has exhibited better high-temperature stability within the temperature range of 200∼800 °C as evidenced by a decay rate of 0.0064 dB/°C, which is significantly lower than the bare FBG (0.0081 dB/°C). Careful investigation shows that the thermal decay of the FBG can be further mediated by regulating the applied torsion and the simulation analysis has demonstrated that applied torsion can effectively introduce compressive stresses into the grating. Moreover, the torsion-assisted FBG also shows better high-temperature wavelength stability, slower heating decay rate, and improved wavelength hysteresis. In addition, the high-temperature strain characteristics of the torsion-assisted FBGs have also been investigated. Given the merits such as easy implementation, no need for complex heat treatment processes, good controllability, and low cost, we envision that the torsion-assisted FBG is promising in the field of high-temperature sensing.
摘要：
In order to achieve carbon neutrality in transportation sector, this study examines the performance of three different fuels in a spark ignition (SI) engine from green and renewable methanol and hydrogen: M0G100 (pure gasoline), M10G90 (90 % gasoline mixed with 10 % methanol), M30G70 (70 % gasoline mixed with 30 % methanol), and M30G70 with hydrogen (7.5 % hydrogen energy share in blended fuel). The study explores the synergistic optimization influences of adding methanol and hydrogen on performance of a gasoline SI engine thorough comparative analysis. The results show that using hydrogen and methanol can improve combustion process of the gasoline engine. The coefficient of variation (COV) of peak combustion pressure for the test gasoline engine using different fuel mixtures (M0G100, M10G90, M30G70, and M30G70/hydrogen) is 16.25 %, 17.58 %, 18.75 %, and 9.55 % respectively. Similarly, the COV of indicated mean effective pressure for these mixtures is 7.6 %, 11.41 %, 33.45 %, and 4.41 % respectively. Additionally, using M30G70 with hydrogen in gasoline engine shows a 14.3 % decrease in fuel consumption and a 12.5 % increase in indicated thermal efficiency. The carbon dioxide (CO2) emissions of the test gasoline engine with M10G90, M30G70 and M30G70/hydrogen fuels are respectively reduced by 7.37 %, 26.78 % and 33.27 % compared to the gasoline engine.
In order to achieve carbon neutrality in transportation sector, this study examines the performance of three different fuels in a spark ignition (SI) engine from green and renewable methanol and hydrogen: M0G100 (pure gasoline), M10G90 (90 % gasoline mixed with 10 % methanol), M30G70 (70 % gasoline mixed with 30 % methanol), and M30G70 with hydrogen (7.5 % hydrogen energy share in blended fuel). The study explores the synergistic optimization influences of adding methanol and hydrogen on performance of a gasoline SI engine thorough comparative analysis. The results show that using hydrogen and methanol can improve combustion process of the gasoline engine. The coefficient of variation (COV) of peak combustion pressure for the test gasoline engine using different fuel mixtures (M0G100, M10G90, M30G70, and M30G70/hydrogen) is 16.25 %, 17.58 %, 18.75 %, and 9.55 % respectively. Similarly, the COV of indicated mean effective pressure for these mixtures is 7.6 %, 11.41 %, 33.45 %, and 4.41 % respectively. Additionally, using M30G70 with hydrogen in gasoline engine shows a 14.3 % decrease in fuel consumption and a 12.5 % increase in indicated thermal efficiency. The carbon dioxide (CO2) emissions of the test gasoline engine with M10G90, M30G70 and M30G70/hydrogen fuels are respectively reduced by 7.37 %, 26.78 % and 33.27 % compared to the gasoline engine.
摘要：
Dry machining has become one of the most promising and sustainable manufacturing processes in mechanical machining. One of the main puzzles for industrial applications of dry machining is tool wear, which are closely related with the transient thermomechanical characteristics of tool-chip interface (TCI). Simultaneously, those characteristics at micro scale can provided the critical insight of cutting mechanics and tool wear in ultrasonic vibration assisted cutting (UVC). However, reports in literature appear to be scarce. In this study the transient model of thermomechanical behavior in TCI is proposed, with a consideration of characteristics changes induced by ultrasonic vibration, as well as a focus on the transient cutting mechanism, as well as stress and friction. The proposed model is validated by comparison with the experimental and published analytical results. Obtained results from the proposed model indicate that the distribution of normal stress and average shear stress are similar to those that are predicted by Zorev's model. However, a noticeable apparent discrepancy appears between the two models regarding the distribution of shear stress. Apparently, the ultrasonic vibration changes the friction via alternating normal and shear stresses, and delays the time for the cutting force and the stress to reach their peak point. Additionally, it is confirmed that the fluctuation and increment of friction coefficient is due to the cutting force reduction in UVC under sustainable dry conditions.
Dry machining has become one of the most promising and sustainable manufacturing processes in mechanical machining. One of the main puzzles for industrial applications of dry machining is tool wear, which are closely related with the transient thermomechanical characteristics of tool-chip interface (TCI). Simultaneously, those characteristics at micro scale can provided the critical insight of cutting mechanics and tool wear in ultrasonic vibration assisted cutting (UVC). However, reports in literature appear to be scarce. In this study the transient model of thermomechanical behavior in TCI is proposed, with a consideration of characteristics changes induced by ultrasonic vibration, as well as a focus on the transient cutting mechanism, as well as stress and friction. The proposed model is validated by comparison with the experimental and published analytical results. Obtained results from the proposed model indicate that the distribution of normal stress and average shear stress are similar to those that are predicted by Zorev's model. However, a noticeable apparent discrepancy appears between the two models regarding the distribution of shear stress. Apparently, the ultrasonic vibration changes the friction via alternating normal and shear stresses, and delays the time for the cutting force and the stress to reach their peak point. Additionally, it is confirmed that the fluctuation and increment of friction coefficient is due to the cutting force reduction in UVC under sustainable dry conditions.
摘要：
Road cracks pose a serious threat to the stability of road structures and traffic safety. Therefore, this paper proposes an optimized accurate road crack segmentation network called MBGBNet, which can solve the problems of complex background, tiny cracks, and irregular edges in road segmentation. First, multi-scale domain feature aggregation is proposed to address the interference of complex background. Second, bidirectional embedding fusion adaptive attention is proposed to capture the features of tiny cracks, and finally, Gaussian weighted edge segmentation algorithm is proposed to ensure the accuracy of crack edge segmentation. In addition, this paper uses the preheated bat optimization algorithm, which can quickly determine the optimal learning rate to converge the equilibrium. In the validation experiments on the self-built dataset, mean intersection over union reaches 80.54% and precision of 86.38%. MBGBNet outperforms the other seven state-of-the-art crack segmentation networks on the three classical crack datasets, highlighting its advanced segmentation capabilities. Therefore, MBGBNet is an effective auxiliary method for solving road safety problems.
通讯机构：
[Yang, Y ] N;Northwestern Polytech Univ, Natl Key Lab Aerosp Flight Dynam, Youyi Rd, Xian 710072, Peoples R China.;Northwestern Polytech Univ, Res Ctr Intelligent Robot, Sch Astronaut, Youyi Rd, Xian 710072, Peoples R China.
关键词：
bilateral synchronization control;communication problem;networked teleoperation robot system;uncertainty problem
摘要：
<jats:title>Abstract</jats:title><jats:p>Bilateral synchronization control for Network Teleoperation Robot System (NTRS) in discrete domain is discussed in this paper, where time delay, data loss and disorder, and quantization error coexist. Firstly, it is assumed that time delay and data loss are asymmetric and randomly vary in the master–slave channel and slave–master channel according to different Markov jump change rules. By introducing the virtual variables, a clever normalization method is proposed for time delay or data loss. It not only uniforms time delay and data loss into a same framework, but also effectively handles the problem of data disorder. And then, a logarithmic quantizer is designed to dispose quantization error. Meanwhile, utilize the sector bound method to describe the quantization error and transform the quantization feedback control problem into a robust control problem, so the familiar robust control methods can be adopted to solve quantization problem. In addition, human and environmental forces are treated as external disturbances and processed using neural network techniques. Subsequently, stochastic stability and synchronization control property are guaranteed by the designed analogous PD controller that consists of proportion, derivative, and uncertainty estimation items. Finally, validity of the proposed method is certified by some simulation examples.</jats:p>
摘要：
Biomass based porous carbon is a green and low-cost promising adsorbents for CO2 capture. However, most of these porous carbon were prepared under high-temperature and even multistep pyrolysis, and possessed poor textural properties and controllability. Here, enzymatic hydrolysis lignin (EHL) was used as carbon source to prepare O-rich N-doped porous carbon (LNPC) through a synthesis strategy that coupled hydrothermal treatment, mechanochemical assistance, and low-temperature activation for the first time. These porous carbon had the large specific surface areas (602.2 similar to 2030.7 m(2)/g), high microporosity, and abundant ultramicroporous (V-ultra) (0.19 cm(3)/g), as well as significant N doping and high O content (30.93 similar to 55.32 %). And the effects of the coupling method, activation temperature, and mechanical pressure and residence time on structural properties of lignin based porous carbon were investigated in detail. We found that the residence time had a good linear correlation for surface areas and micropore volume, respectively, meanwhile, the mechanical pressing exhibited better linear correlation for O content of LNPC, implied the preparation method had good controllability. LSY-P20-T20 prepared at activation temperature of 600 degree celsius with the mechanical pressure and time (20 MPa and 20 min) had the highest V-ultra, and high O content, and possessed the highest CO2 uptake (5.00 mmol/g). Subsequently, we found that the narrow micropore volume (with d < 1.0 nm) was the main factor for CO2 adsorption capacity, while O content showed more significant impact on determining CO2/N-2 selectivity and isosteric heat of adsorption (Q(st)) of LNPCs. This work provided a new feasible approach for cost-effective carbon-based adsorbents for CO2 capture.
摘要：
The modulation mechanism of iron (Fe) and manganese (Mn) in transition-metal elements on the interface bonding and mechanical properties of bronze (Cu3Sn)-based/diamond composites is investigated through first-principles calculations. Transition-elements-doping scenarios are investigated employing six-layer slab models. It is revealed that the doping of Fe or Mn can make the Cu3Sn/diamond interface more stable, which effectively improves the wettability of the Cu3Sn/diamond interface based on the calculation results and analysis of interface energy, differential charge density model, and density of states. However, co-doping with both Fe and Mn weakens the wettability of the Cu3Sn/diamond interface. Finally, wettability tests and microstructure characterizations demonstrate that the doping of Fe and Mn represents an effective approach to controlling the interface bonding performance of bronze/diamond composites. Fe- and Mn-doping effects on the interface binding and mechanical properties of Cu3Sn/diamond composites are studied using first-principles calculations. Analysis of interface energy, charge density models, and density of states reveals that individual Fe or Mn doping improves Cu3Sn//diamond interface wettability. Conversely, co-doping weakens Cu3Sn/diamond interface wettability. Wettability tests and microscopic characterization validate these findings.image (c) 2023 WILEY-VCH GmbH
关键词：
Lithium-ion battery;Thermal regulation strategy;Spectral method;Thermoelectric cooler;Nonlinear model predictive control
摘要：
An efficient thermal regulation strategy is of great significance in ensuring the safe operation of electric vehicles (EVs). However, the commonly used thermal management systems suffer from the problem of not being able to accurately and uniformly control the temperature distribution of lithium-ion batteries (LIBs), which poses great risks to the thermal safety control of batteries. In this paper, an advanced thermal management system for LIBs based on thermoelectric cooler (TEC) was designed to overcome the above problems. First, a temperature regulation mechanism model for LIB was constructed. Then, a novel temperature distribution modeling method for TEC was developed by using spectral method. This modeling process took into account the unsteady heat transfer characteristics, which can achieve high modeling accuracy. Next, a state space model of temperature control was constructed by combining a differential model of LIB with the proposed cooler model. On this basis, a temperature control strategy for LIB using nonlinear model predictive control (NMPC) method was proposed to optimize the cooling process because of its superior processing ability to constraints and nonlinearity. A various of experiments and verifications demonstrated that the presented thermal regulation strategy was effective and feasible.
关键词：
Battery electric vehicle;Energy flow;Vehicle test;Integrated simulation;Driving cycles
摘要：
To comprehensively investigate the energy distribution and performance of a battery electric vehicle (BEV), an integrated simulation model based on energy flow test data was developed and validated, and the energy flow characteristics of the BEV throughout the entire driving range in low-temperature conditions were studied. The results show that the battery heat loss and motor energy loss first increase and then decrease with an increment in cycle number, while the transmission loss first decreases and then remains constant. The energy recovery efficiency demonstrates an incremental trend with the number of cycles post-battery charging, while the energy utilization efficiency experiences a decline due to escalating energy losses within the power distribution unit (PDU). The energy flow characteristics of the BEV exhibit a pronounced connection with the speed properties inherent in the driving cycle. The battery charge energy is maximal under Urban Dynamometer Driving Schedule (UDDS), whereas the electricity consumption per 100 km is minimized under China light-duty vehicle test cyclepassenger (CLTC-P). Conversely, the energy utilization and recovery efficiency are the highest under Worldwide Light-duty Test Cycle (WLTC). These findings provide directional insights, theoretical support and data basis for rational performance evaluation and optimal energy distribution of BEVs.
摘要：
The white-light-emitting devices (WLEDs) for urban ecological lighting remain the challenge. The current urban lighting system destroys the growth habits of plants and leads to inhibition of plant growth, reduced branching, smaller leaf area and reduced total dry weight due to excessive blue light. In this work, a series of blue -green and red dual-emission Na 3 Ba 2 Ca(PO 4 ) 3 :Eu 2+ , Mn 2+ phosphors have been successfully synthesized by the hightemperature solid -state reaction method. The crystal structure, the occupancy of the dopant ions and the luminescence characteristics were carefully investigated. The excitation and emission spectra as well as the decay lifetime confirm the effective energy transfer from Eu 2+ to Mn 2+ , which leads to a tunable luminescence with greatly reduced blue emission. Especially, the optimal Na 3 Ba 2 Ca(PO 4 ) 3 :0.02Eu 2+ , 0.11Mn 2+ phosphor demonstrates a high internal quantum yield of 99.7%. At 150 degrees C, the luminescence intensity of Na 3 Ba 2 Ca (PO 4 ) 3 :0.02Eu 2+ , 0.11Mn 2+ can maintain 64.5% of room temperature intensity. In addition, the WLED device fabricated with Na 3 Ba 2 Ca(PO 4 ) 3 :Eu 2+ , Mn 2+ phosphor shows white light emission with CIE coordinates of (0.3800, 0.3852), rendering index (Ra) of 65.4 and correlated color temperature (CCT) of 3640 K. These results confirm that the Na 3 Ba 2 Ca(PO 4 ) 3 :Eu 2+ , Mn 2+ phosphor can be applied as a white light source in the urban ecological field.
作者机构：
[文韬; 代兴勇; 李浪; 刘豪] College of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Hunan, Changsha, 410004, China
关键词：
District energy system (DES);Renewable energy;Game theory;Deep decarbonization;Subsidy strategy;Optimization
摘要：
Renewable district energy systems present a promising solution for decarbonizing the energy sector. However, optimal strategies to mitigate the financial challenges of deep decarbonization are still underexplored. This study aims to optimize government subsidy strategies and users' system designs to facilitate cost-effective deep decarbonization using game theory. Two indicators, the renewable generation rate (RGR) and the self-sufficiency rate (SSR), are formulated to understand the principles of achieving deep decarbonization. Additionally, the study introduces a new strategy called subsidy plus energy storage service (SUB + ESS), contrasting it with the traditional subsidy-only strategy. Key findings indicate that merely increasing the RGR requirements does not achieve deep decarbonization due to energy mismatches. Restricting the SSR requirements proves effective in achieving deep decarbonization but imposes a significant economic burden on the government. When the SSR requirement is set at 100%, carbon emissions are reduced by 93%, but the government's subsidy expenditure increases nearly fivefold. In contrast to the subsidy-only strategy, the novel SUB + ESS strategy, with a 100% SSR requirement, reduces government expenditure by approximately 52% and lowers total expenditure by 19.7%. A two-stage decarbonization strategy is proposed: initially, offering subsidies is sufficient, but as deeper decarbonization is pursued, establishing energy storage service becomes essential.
