In the development of China's agricultural production, wheat, as a food crop, plays an important role. Its own output will have a direct impact on the safe development of agriculture. Therefore, when planting whea...In the development of China's agricultural production, wheat, as a food crop, plays an important role. Its own output will have a direct impact on the safe development of agriculture. Therefore, when planting wheat in the field, the field management of wheat must be strengthened, especially the comprehensive prevention and control of diseases and insect pests occurring in the growth process of wheat, which cannot be taken lightly. If diseases and insect pests cannot be effectively and timely controlled, the yield and quality of wheat will be severely reduced. When controlling wheat diseases and insect pests, it is necessary to master the specific characteristics of the diseases and insect pests, and adopt various technologies such as biology and agriculture to carry out comprehensive prevention and control, so as to improve the quality and yield of wheat.展开更多
Aero-engines,the core of air travel,rely on advanced high strength-toughness alloys(THSAs)such as titanium alloys,nickel-based superalloys,intermetallics,and ultra-high strength steel.The precision of cutting techniqu...Aero-engines,the core of air travel,rely on advanced high strength-toughness alloys(THSAs)such as titanium alloys,nickel-based superalloys,intermetallics,and ultra-high strength steel.The precision of cutting techniques is crucial for the manufacture of key components,including blades,discs,shafts,and gears.However,machining THSAs pose significant challenges,including high cutting forces and temperatures,which lead to rapid tool wear,reduced efficiency,and compromised surface integrity.This review thoroughly explores the current landscape and future directions of cutting techniques for THSAs in aero-engines.It examines the principles,mechanisms,and benefits of energy-assisted cutting technologies like laser-assisted machining and cryogenic cooling.The review assesses various tool preparation methods,their effects on tool performance,and strategies for precise shape and surface integrity control.It also outlines intelligent monitoring technologies for machining process status,covering aspects such as tool wear,surface roughness,and chatter,contributing to intelligent manufacturing.Additionally,it highlights emerging trends and potential future developments,including multi-energy assisted cutting mechanisms,advanced cutting tools,and collaborative control of structure shape and surface integrity,alongside intelligent monitoring software and hardware.This review serves as a reference for achieving efficient and high-quality manufacturing of THSAs in aero-engines.展开更多
Deep coal mining has become increasingly routine,and its complex geomechanical environment has led to higher intensity and frequency of rock bursts and coal and gas outbursts,while also resulting in more diverse disas...Deep coal mining has become increasingly routine,and its complex geomechanical environment has led to higher intensity and frequency of rock bursts and coal and gas outbursts,while also resulting in more diverse disaster types,with their coupling giving rise to more destructive compound disasters.Therefore,investigating and elucidating the disaster-causing mechanisms of coal-rock-gas compound disasters,developing effective monitoring and early warning systems,and exploring novel mitigation technologies are crucial for ensuring safe and efficient mine operations.This study systematically reviews the research progress and current status of coal-rock-gas compound disasters,comprehensively analyzes and summarizes three primary controlling factors influencing compound disasters:objective factors,anthropogenic factors,and natural factors.Based on the driving force sources,triggering and transformation sequence,and duration,the disaster formation model of coal-rock-gas compound disasters is refined.The full-cycle incubation and evolution process of coal-rock-gas compound disasters is dissected,and the inducing and transformation mechanisms underlying their occurrence are revealed,and the occurrence thresholds of compound disasters are defined.Based on the evolution patterns of overlying strata structures and gas distribution characteristics,coal-rock-gas compound disasters are classified into impact-induced outburst type and outburst-induced impact type.The study comprehensively describes the multi-source monitoring approaches for coal-rock-gas compound disasters,as well as a multi-parameter integrated early-warning system.A technical system integrating regional prevention and local risk mitigation for outburst elimination and rockburst pressure reduction is summarized,and a novel concept of compound disaster prevention and control based on structural regulation is proposed.The study discusses key technical challenges in the research on coal-rock-gas compound disasters,such as multi-field coupling mechanism studies,development of similar materials,refined geological exploration and modeling,optimization of monitoring and early-warning models,and exploration of novel prevention and control technologies,with the aim of further advancing research in the field of coal-rock-gas compound disasters,thereby ensuring the safe and efficient extraction of deep coal resources.展开更多
文摘In the development of China's agricultural production, wheat, as a food crop, plays an important role. Its own output will have a direct impact on the safe development of agriculture. Therefore, when planting wheat in the field, the field management of wheat must be strengthened, especially the comprehensive prevention and control of diseases and insect pests occurring in the growth process of wheat, which cannot be taken lightly. If diseases and insect pests cannot be effectively and timely controlled, the yield and quality of wheat will be severely reduced. When controlling wheat diseases and insect pests, it is necessary to master the specific characteristics of the diseases and insect pests, and adopt various technologies such as biology and agriculture to carry out comprehensive prevention and control, so as to improve the quality and yield of wheat.
基金National Natural Science Foundation of China(Nos.92160301,92060203,52175415,and 52205475)Science Center for Gas Turbine Project(No.P2023-B-IV-003-001)+1 种基金Natural Science Foundation of Jiangsu Province(No.BK20210295)Fundamental Research Funds for the Central Universities(Nos.NS2023028 and NG2024015)。
文摘Aero-engines,the core of air travel,rely on advanced high strength-toughness alloys(THSAs)such as titanium alloys,nickel-based superalloys,intermetallics,and ultra-high strength steel.The precision of cutting techniques is crucial for the manufacture of key components,including blades,discs,shafts,and gears.However,machining THSAs pose significant challenges,including high cutting forces and temperatures,which lead to rapid tool wear,reduced efficiency,and compromised surface integrity.This review thoroughly explores the current landscape and future directions of cutting techniques for THSAs in aero-engines.It examines the principles,mechanisms,and benefits of energy-assisted cutting technologies like laser-assisted machining and cryogenic cooling.The review assesses various tool preparation methods,their effects on tool performance,and strategies for precise shape and surface integrity control.It also outlines intelligent monitoring technologies for machining process status,covering aspects such as tool wear,surface roughness,and chatter,contributing to intelligent manufacturing.Additionally,it highlights emerging trends and potential future developments,including multi-energy assisted cutting mechanisms,advanced cutting tools,and collaborative control of structure shape and surface integrity,alongside intelligent monitoring software and hardware.This review serves as a reference for achieving efficient and high-quality manufacturing of THSAs in aero-engines.
基金Projects(U23B2093,52034009)supported by the National Natural Science Foundation of ChinaProject(2022YFC3004602)supported by the National Key R&D Program of China。
文摘Deep coal mining has become increasingly routine,and its complex geomechanical environment has led to higher intensity and frequency of rock bursts and coal and gas outbursts,while also resulting in more diverse disaster types,with their coupling giving rise to more destructive compound disasters.Therefore,investigating and elucidating the disaster-causing mechanisms of coal-rock-gas compound disasters,developing effective monitoring and early warning systems,and exploring novel mitigation technologies are crucial for ensuring safe and efficient mine operations.This study systematically reviews the research progress and current status of coal-rock-gas compound disasters,comprehensively analyzes and summarizes three primary controlling factors influencing compound disasters:objective factors,anthropogenic factors,and natural factors.Based on the driving force sources,triggering and transformation sequence,and duration,the disaster formation model of coal-rock-gas compound disasters is refined.The full-cycle incubation and evolution process of coal-rock-gas compound disasters is dissected,and the inducing and transformation mechanisms underlying their occurrence are revealed,and the occurrence thresholds of compound disasters are defined.Based on the evolution patterns of overlying strata structures and gas distribution characteristics,coal-rock-gas compound disasters are classified into impact-induced outburst type and outburst-induced impact type.The study comprehensively describes the multi-source monitoring approaches for coal-rock-gas compound disasters,as well as a multi-parameter integrated early-warning system.A technical system integrating regional prevention and local risk mitigation for outburst elimination and rockburst pressure reduction is summarized,and a novel concept of compound disaster prevention and control based on structural regulation is proposed.The study discusses key technical challenges in the research on coal-rock-gas compound disasters,such as multi-field coupling mechanism studies,development of similar materials,refined geological exploration and modeling,optimization of monitoring and early-warning models,and exploration of novel prevention and control technologies,with the aim of further advancing research in the field of coal-rock-gas compound disasters,thereby ensuring the safe and efficient extraction of deep coal resources.
