作者机构：
[Guiliang Gong; Zhongliang Gong; Dan Huang; Xiaoqiang Li] Department of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha 410004, China;Zoomlion Heavy Industry Science and Technology Co., Ltd., Changsha 410013, China;[Qiang Luo] State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China;[Ningtao Peng] Department of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;[Dian Lu] Department of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha 410004, China<&wdkj&>Zoomlion Heavy Industry Science and Technology Co., Ltd., Changsha 410013, China
通讯机构：
[Guiliang Gong] D;Department of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha 410004, China
摘要：
To date, existing research on the distributed flexible job shop scheduling problem typically overlooks the insertion of rush orders, i.e., it is assumed that once an order starts processing, other jobs cannot be inserted. However, in actual production, with the increasing demand for multiple varieties, small batches, and personalization, order insertion has become very common. In this paper, we propose a distributed flexible job shop scheduling problem considering rush order insertion (DFJSPR) for the first time; and design a two-stage memetic algorithm (TMA) to solve the DFJSPR with the optimization objectives of minimizing the makespan, total energy consumption, and total delay of jobs. In the TMA, a four-layer encoding operator and an effective initialization method for balancing load and transportation are designed to improve the quality of initial population. Some effective crossover, mutation, and local search operators are also designed to fully exploit the algorithm's solution space as well as improve its convergence speed. Finally, a new insertion rescheduling method is presented to reduce the total delay of jobs and makespan by making full use of the machine’s idle time. Sixty DFJSPR benchmark instances are constructed, and comprehensive experiments are conducted to demonstrate the superiority of the TMA. These studies will provide a theoretical basis for practical production scheduling in distributed flexible job shops and help production decision-makers obtain optimal scheduling schemes when considering rush order insertion problems.
To date, existing research on the distributed flexible job shop scheduling problem typically overlooks the insertion of rush orders, i.e., it is assumed that once an order starts processing, other jobs cannot be inserted. However, in actual production, with the increasing demand for multiple varieties, small batches, and personalization, order insertion has become very common. In this paper, we propose a distributed flexible job shop scheduling problem considering rush order insertion (DFJSPR) for the first time; and design a two-stage memetic algorithm (TMA) to solve the DFJSPR with the optimization objectives of minimizing the makespan, total energy consumption, and total delay of jobs. In the TMA, a four-layer encoding operator and an effective initialization method for balancing load and transportation are designed to improve the quality of initial population. Some effective crossover, mutation, and local search operators are also designed to fully exploit the algorithm's solution space as well as improve its convergence speed. Finally, a new insertion rescheduling method is presented to reduce the total delay of jobs and makespan by making full use of the machine’s idle time. Sixty DFJSPR benchmark instances are constructed, and comprehensive experiments are conducted to demonstrate the superiority of the TMA. These studies will provide a theoretical basis for practical production scheduling in distributed flexible job shops and help production decision-makers obtain optimal scheduling schemes when considering rush order insertion problems.
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：
Based on the investigation of mechanical response and microstructure evolution of a commercial 7003 aluminum alloy under high-speed impact, a new simple and effective method was proposed to determine the critical strain required for the nucleation of adiabatic shear band (ASB). The deformation results of cylindrical and hat-shaped samples show that the critical strain required for ASB nucleation corresponds to the strain at the first local minimum after peak stress on the first derivative curve of true stress−true strain. The method of determining the critical strain for the nucleation of ASB through the first derivative of the flow stress curve is named the first derivative method. The proposed first derivative method is not only applicable to the 7003 aluminum alloy, but also to other metal materials, such as commercial purity titanium, WY-100 steel, and AM80 magnesium alloy. This proves that it has strong universality.
Based on the investigation of mechanical response and microstructure evolution of a commercial 7003 aluminum alloy under high-speed impact, a new simple and effective method was proposed to determine the critical strain required for the nucleation of adiabatic shear band (ASB). The deformation results of cylindrical and hat-shaped samples show that the critical strain required for ASB nucleation corresponds to the strain at the first local minimum after peak stress on the first derivative curve of true stress−true strain. The method of determining the critical strain for the nucleation of ASB through the first derivative of the flow stress curve is named the first derivative method. The proposed first derivative method is not only applicable to the 7003 aluminum alloy, but also to other metal materials, such as commercial purity titanium, WY-100 steel, and AM80 magnesium alloy. This proves that it has strong universality.
摘要：
The preparation of efficient CO2 adsorbents is crucial for CO2 capture. Compared to polymer-based carbons and metal-organic frameworks (MOFs), biomass-based carbon exhibits lower adsorption performance. Here, we prepared high oxygen doped ultramicroporous carbon through hydrothermal treatment and mechanical compaction assisted KOH activation. The study found that mechanical compaction treatment can target a 24 % increase in the volume of ultra-micropores, resulting in a CO2 capture of the prepared ultramicroporous carbon reaching 5.6 mmol g−1, which is 22 % higher than that of conventionally prepared porous carbon. Molecular simulation calculations roughly estimated that functional groups and pore structures contribute 60 % and 40 %, respectively, to CO2 capture at 0.15 bar, and 47 % and 53 % at 1 bar. Meanwhile, we found that the selectivity of CO2/N2 is mainly related to the trend of oxygen functional groups, and is not significantly correlated with the micropore volume smaller than 0.7 nm. Theoretical calculations revealed that the introduction of oxygen groups into porous carbon resulted in an increase in selectivity of over 150 %, which is stronger than the effect of pore structure. This work provides valuable theoretical and experimental support for the design, preparation, and application of adsorbents for capturing CO2 in flue gas.
The preparation of efficient CO2 adsorbents is crucial for CO2 capture. Compared to polymer-based carbons and metal-organic frameworks (MOFs), biomass-based carbon exhibits lower adsorption performance. Here, we prepared high oxygen doped ultramicroporous carbon through hydrothermal treatment and mechanical compaction assisted KOH activation. The study found that mechanical compaction treatment can target a 24 % increase in the volume of ultra-micropores, resulting in a CO2 capture of the prepared ultramicroporous carbon reaching 5.6 mmol g−1, which is 22 % higher than that of conventionally prepared porous carbon. Molecular simulation calculations roughly estimated that functional groups and pore structures contribute 60 % and 40 %, respectively, to CO2 capture at 0.15 bar, and 47 % and 53 % at 1 bar. Meanwhile, we found that the selectivity of CO2/N2 is mainly related to the trend of oxygen functional groups, and is not significantly correlated with the micropore volume smaller than 0.7 nm. Theoretical calculations revealed that the introduction of oxygen groups into porous carbon resulted in an increase in selectivity of over 150 %, which is stronger than the effect of pore structure. This work provides valuable theoretical and experimental support for the design, preparation, and application of adsorbents for capturing CO2 in flue gas.
摘要：
In this article, the concept of topological rainbow is introduced into the plate-mode waves system of 1D phononic crystal slabs, achieving adjustable topological elastic rainbow trapping by employing gradient-tuned Su-Schrieffer-Heeger (SSH) structures. First, based on the classical SSH model, a phononic crystal slab composed of steel and aluminum is set up, and the band structure of plate-mode waves is studied using the finite-element method. Band inversion can be induced by changing the height of the steel in the unit cell, leading to topological phase transitions. Then, phononic crystals with different topological properties are connected to form a phononic crystal slab, realizing topological interface states. Furthermore, a sandwich-like ultrathin structure is constructed to couple the adjacent two topological interface states. Finally, a 1D alternating SSH structure of phononic crystal slab is designed under gradient structural parameters, and based on eigenfrequency and full-wave simulation, adjustable topological rainbow trapping based on coupled interface states is achieved. The designed device can trap wide frequencies exceeding 15 kHz, providing more possibilities for the design of elastic-energy-harvesting devices. Topological rainbow in 1D phononic crystal slabs, achieving adjustable elastic trapping using gradient-tuned Su-Schrieffer-Heeger structures, is introduced. By varying steel heights, band inversion induces topological phase transitions, forming interface states. A sandwich-like structure couples these interface states, enabling rainbow trapping frequencies exceeding 15 kHz, outside the common bandgap, expanding design possibilities for energy-harvesting devices.image (c) 2024 WILEY-VCH GmbH
摘要：
The fiber Bragg gratings (FBGs) are important for the fiber sensing systems. The high-quality FBGs were inscribed by picosecond laser direct writing method in single-mode fiber for the first time. The mechanism of refractive index (RI) modulation in fiber by picosecond laser was revealed by Raman spectra and the results show that the RI modulation is mainly caused by the increase of fictive temperature. Further high-temperature testing showed that the FBGs have good stability under temperature of 1130 degrees C. In addition, the XRD experimental results reveal that the probable cause of FBGs failure is mainly caused by cracks due to crystallization and redundant stresses at 1150 degrees C. This research provides an effective, economic, fast and reliable new approach for the fabrication of FBGs with high temperature resistant. In other words, the FBGs fabricated by picosecond laser direct writing demonstrate great potential for applications in extreme environments.
摘要：
In response to global energy and environmental challenges, this study systematically evaluates performance of methanol-gasoline blends (M100, M85) in comparison to pure gasoline in a spark-ignition (SI) engine. Through experimental data and numerical simulations, the combustion characteristics, energy flow distribution, and thermomechanical conversion processes of the three fuels were analyzed across compression ratios (CRs) ranging from 11 to 15. Under full-load conditions at 3500 r/min, gasoline showed 7.58 % and 8.69 % higher power outputs than M100 and M85, respectively. Additionally, when operating at the same speed under high loads (exceeding 125 Nm), methanol demonstrated better fuel economy than gasoline. This improvement stems from increased high-pressure cycle work, reduced heat transfer, and incomplete combustion losses. Both the effective expansion ratio (EER) and energy economy efficiency (EEE) peaked at a CR of approximately 13, beyond which efficiency gains plateaued while knock propensity intensified. Between 2500 and 3500 r/min with CR exceeding 13, methanol blends exhibited 18–23 % higher efficiency than gasoline, owing to their superior knock resistance resulting from greater octane sensitivity. The combustion characteristics of M85 fell between those of gasoline and M100, highlighting its potential as promising alternative fuel. These findings provide critical insights into enhancing methanol-gasoline engines through CR optimization, combustion phasing (CA50) calibration, and implementation of an effective thermal conversion process. The study systematically analyzes the combustion characteristics and energy flow synergy of high-proportion methanol-gasoline blends under high CR, along with the interactive effects of CR, load, and combustion timing.
In response to global energy and environmental challenges, this study systematically evaluates performance of methanol-gasoline blends (M100, M85) in comparison to pure gasoline in a spark-ignition (SI) engine. Through experimental data and numerical simulations, the combustion characteristics, energy flow distribution, and thermomechanical conversion processes of the three fuels were analyzed across compression ratios (CRs) ranging from 11 to 15. Under full-load conditions at 3500 r/min, gasoline showed 7.58 % and 8.69 % higher power outputs than M100 and M85, respectively. Additionally, when operating at the same speed under high loads (exceeding 125 Nm), methanol demonstrated better fuel economy than gasoline. This improvement stems from increased high-pressure cycle work, reduced heat transfer, and incomplete combustion losses. Both the effective expansion ratio (EER) and energy economy efficiency (EEE) peaked at a CR of approximately 13, beyond which efficiency gains plateaued while knock propensity intensified. Between 2500 and 3500 r/min with CR exceeding 13, methanol blends exhibited 18–23 % higher efficiency than gasoline, owing to their superior knock resistance resulting from greater octane sensitivity. The combustion characteristics of M85 fell between those of gasoline and M100, highlighting its potential as promising alternative fuel. These findings provide critical insights into enhancing methanol-gasoline engines through CR optimization, combustion phasing (CA50) calibration, and implementation of an effective thermal conversion process. The study systematically analyzes the combustion characteristics and energy flow synergy of high-proportion methanol-gasoline blends under high CR, along with the interactive effects of CR, load, and combustion timing.
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.
期刊：
International Journal of Impact Engineering,2025年208:105560 ISSN：0734-743X
通讯作者：
Wen Shao
作者机构：
State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Central South University, Changsha 410083, China;College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha 410004, China;[Guoxi Feng; Jinyuan Tang; Wen Shao; Weiwei Huang; Tingting Jiang; Hao Li] State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Central South University, Changsha 410083, China<&wdkj&>College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;[Xuelin Chen] State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Central South University, Changsha 410083, China<&wdkj&>College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China<&wdkj&>School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha 410004, China
通讯机构：
[Wen Shao] S;State Key Laboratory of Precision Manufacturing for Extreme Service Performance, Central South University, Changsha 410083, China<&wdkj&>College of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China
摘要：
Hardened AISI 9310 steel, renowned for its superior mechanical properties, is widely employed in aviation transmission systems. While the finite element method based on the Johnson-Cook(J-C) has proven effective for studying chip formation and machining performance, research on the mechanical behavior of hardened AISI 9310 steel remains limited, particularly concerning accurate J-C parameters and chip formation mechanisms. In this study, the J-C model parameters for hardened AISI 9310 steel were determined through Quasi-static tensile tests, Split Hopkinson Tensile/Pressure Bar (SHTB/SHPB) tests, notched round bar experiments and corresponding finite element simulations. These calibrated parameters were subsequently integrated into a finite element model for orthogonal cutting simulations, validated by experimental orthogonal cutting tests. Results confirmed that the derived J-C parameters enable accurate prediction of key machining process variables. Superior machining performance, characterized by reduced cutting forces, thinner chips, and a shorter tool-chip contact length, was achieved at low feed rates and high cutting speeds. Tool tip temperature is primarily governed by cutting speed. Increasing cutting speed generates a heat migration effect, leading to an improved thermal environment at the tool tip.Conversely, higher feed rates elevate cutting forces and expand the high-temperature zone on the rake face, inducing significant cumulative thermal damage and degradation of machining performance. These results provide critical insights for optimizing chip formation mechanisms and process parameters in hardened steels.
Hardened AISI 9310 steel, renowned for its superior mechanical properties, is widely employed in aviation transmission systems. While the finite element method based on the Johnson-Cook(J-C) has proven effective for studying chip formation and machining performance, research on the mechanical behavior of hardened AISI 9310 steel remains limited, particularly concerning accurate J-C parameters and chip formation mechanisms. In this study, the J-C model parameters for hardened AISI 9310 steel were determined through Quasi-static tensile tests, Split Hopkinson Tensile/Pressure Bar (SHTB/SHPB) tests, notched round bar experiments and corresponding finite element simulations. These calibrated parameters were subsequently integrated into a finite element model for orthogonal cutting simulations, validated by experimental orthogonal cutting tests. Results confirmed that the derived J-C parameters enable accurate prediction of key machining process variables. Superior machining performance, characterized by reduced cutting forces, thinner chips, and a shorter tool-chip contact length, was achieved at low feed rates and high cutting speeds. Tool tip temperature is primarily governed by cutting speed. Increasing cutting speed generates a heat migration effect, leading to an improved thermal environment at the tool tip.Conversely, higher feed rates elevate cutting forces and expand the high-temperature zone on the rake face, inducing significant cumulative thermal damage and degradation of machining performance. These results provide critical insights for optimizing chip formation mechanisms and process parameters in hardened steels.
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：
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.
期刊：
Renewable & Sustainable Energy Reviews,2025年219:115847 ISSN：1364-0321
通讯作者：
Duan, Xiongbo;Sun, ZQ
作者机构：
[Zhou, Feng; Wu, Chenghao] Cent South Univ Forestry & Technol, Coll Mech & Elect Engn, Changsha 410004, Peoples R China.;[Fu, Jianqin; Zhou, Feng; Liu, Jingping] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China.;[Sun, Zhiqiang; Sun, ZQ; Duan, Xiongbo; Duan, XB] Cent South Univ, Hunan Engn Res Ctr Clean & Low Carbon Energy Techn, Sch Energy Sci & Engn, Changsha 410083, Peoples R China.
通讯机构：
[Sun, ZQ ; Duan, XB] C;Cent South Univ, Hunan Engn Res Ctr Clean & Low Carbon Energy Techn, Sch Energy Sci & Engn, Changsha 410083, Peoples R China.
关键词：
Hydrogen internal combustion engine;Mixture formation;Abnormal combustion;Combustion control strategy;NOx emissions
摘要：
Fossil fuel use raises concerns regarding environmental pollution and limited storage capacity. Internal combustion engines significantly depend on the conventional gasoline and diesel, emphasizing the need for alternative fuels. Hydrogen is currently gaining attention as a potential clean energy alternative to traditional fossil fuels owing to its zero carbon emissions, high energy density, fast refueling, compatibility with the existing infrastructure, flexibility, and versatility. Hydrogen use in internal combustion engines signifies a paradigm shift in the engine community toward cleaner and more sustainable transportation solutions. However, challenges such as production costs, distribution infrastructure, and security requirements must be addressed for widespread use. Ongoing research aims to overcome these challenges and enhance the feasibility of using hydrogen as a carbon-free energy source for the engines. This study comprehensively overviews recent research progress and advancements in hydrogen internal combustion engine in terms of the mixture formation mechanism, combustion modes, abnormal combustion mechanism, and the formation mechanism of the nitrogen oxide emissions. In addition, advanced combustion control strategies and technologies have been proposed and summarized to regulate abnormal combustion and nitrogen oxide emissions in the hydrogen engine. The main objectives of this study are to overcome or address these challenges and problems and further enhance the feasibility of hydrogen as a carbon-free alternative fuel for the engine.
Fossil fuel use raises concerns regarding environmental pollution and limited storage capacity. Internal combustion engines significantly depend on the conventional gasoline and diesel, emphasizing the need for alternative fuels. Hydrogen is currently gaining attention as a potential clean energy alternative to traditional fossil fuels owing to its zero carbon emissions, high energy density, fast refueling, compatibility with the existing infrastructure, flexibility, and versatility. Hydrogen use in internal combustion engines signifies a paradigm shift in the engine community toward cleaner and more sustainable transportation solutions. However, challenges such as production costs, distribution infrastructure, and security requirements must be addressed for widespread use. Ongoing research aims to overcome these challenges and enhance the feasibility of using hydrogen as a carbon-free energy source for the engines. This study comprehensively overviews recent research progress and advancements in hydrogen internal combustion engine in terms of the mixture formation mechanism, combustion modes, abnormal combustion mechanism, and the formation mechanism of the nitrogen oxide emissions. In addition, advanced combustion control strategies and technologies have been proposed and summarized to regulate abnormal combustion and nitrogen oxide emissions in the hydrogen engine. The main objectives of this study are to overcome or address these challenges and problems and further enhance the feasibility of hydrogen as a carbon-free alternative fuel for the engine.
作者机构：
[Yang, Qi-Hua; Luo, Zhi-Wei; Cai, Ge-Mei; Li, Gui-Hua] Cent South Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.;[Yang, Qi-Hua; Cai, Ge-Mei; Li, Gui-Hua] Cent South Univ, Sci Ctr Phase Diagram & Mat Design & Manufacture, Changsha 410083, Peoples R China.;[Li, Gui-Hua] Guilin Univ Elect Technol, Sch Mat Sci & Engn, Guilin 541004, Peoples R China.;[Li, Gui-Hua] Guilin Univ Elect Technol, Guangxi Key Lab Informat Mat, Guilin 541004, Peoples R China.;[Si, Jia-Yong] Cent South Univ Forestry & Technol, Coll Mech & Elect Engn, Changsha 410004, Peoples R China.
通讯机构：
[Cai, GM ] C;Cent South Univ, Sch Mat Sci & Engn, Changsha 410083, Peoples R China.
关键词：
Broadband;Near-infrared phosphor;LED;Optical temperature sensing;Blood oxygen saturation analysis
摘要：
Near-infrared (NIR) light sources have important applications in biomedical detection, food inspection, biochemical sensing, night vision, and other fields. Developing a broadband NIR luminescent material with multifunction will help the application and promotion of NIR light sources in various fields. This work designed Cr 3+ to occupy the weaker crystal field sites in the phosphate KInP 2 O 7 (KIPO) lattice for achieving NIR phosphors with a broad emission band. Under 472 nm excitation, KIPO: Cr 3+ exhibits NIR broadband emission centering ∼900 nm owing to the 4 T 2 → 4 A 2 transition of Cr 3+ in InO 6 . The full width at half maximum (FWHM) is as large as 175 nm as its weak crystal field strength . Besides, the emission intensity, FWHM, and fluorescence lifetime of KIPO: 0.05Cr 3+ were systematically investigated in response to temperature. A wide range of highly temperature-sensitive performances (1.92 % K −1 @ 423 K and 1.67 % K −1 @ 393 K) from 298 K to 573 K were obtained. Meanwhile, KIPO: 0.05Cr 3+ phosphors were encapsulated with a 660 nm LED chip to obtain a red-NIR pc-LED, demonstrating the potential application of the newly developed valuable NIR phosphors for oxygen saturation detection. This work hatches out a new idea for the development of new multifunctional NIR luminescent materials integrating optical temperature sensing and blood oxygen detection.
Near-infrared (NIR) light sources have important applications in biomedical detection, food inspection, biochemical sensing, night vision, and other fields. Developing a broadband NIR luminescent material with multifunction will help the application and promotion of NIR light sources in various fields. This work designed Cr 3+ to occupy the weaker crystal field sites in the phosphate KInP 2 O 7 (KIPO) lattice for achieving NIR phosphors with a broad emission band. Under 472 nm excitation, KIPO: Cr 3+ exhibits NIR broadband emission centering ∼900 nm owing to the 4 T 2 → 4 A 2 transition of Cr 3+ in InO 6 . The full width at half maximum (FWHM) is as large as 175 nm as its weak crystal field strength . Besides, the emission intensity, FWHM, and fluorescence lifetime of KIPO: 0.05Cr 3+ were systematically investigated in response to temperature. A wide range of highly temperature-sensitive performances (1.92 % K −1 @ 423 K and 1.67 % K −1 @ 393 K) from 298 K to 573 K were obtained. Meanwhile, KIPO: 0.05Cr 3+ phosphors were encapsulated with a 660 nm LED chip to obtain a red-NIR pc-LED, demonstrating the potential application of the newly developed valuable NIR phosphors for oxygen saturation detection. This work hatches out a new idea for the development of new multifunctional NIR luminescent materials integrating optical temperature sensing and blood oxygen detection.
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.
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.
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>
