期刊文献+
共找到477,224篇文章
< 1 2 250 >
每页显示 20 50 100
Hot Compression Deformation Behavior and Processing Maps of Mg-Zn-Mn(-Sn)-Ca Alloy
1
作者 Chen Xia Zhu Yulong +2 位作者 Liu Quanyi Zhang Dingfei Pan Fusheng 《稀有金属材料与工程》 北大核心 2026年第3期627-635,共9页
The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from... The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from 0.001 s^(-1) to 1 s^(-1).The results show that the addition of Sn promotes dynamic recrystallization(DRX),and CaMgSn phases can act as nucleation sites during the compression deformation.Flow stress increases with increasing the strain rate and decreasing the temperature.Both the ZM61-0.5Ca and ZMT612-0.5Ca alloys exhibit obvious DRX characteristics.CaMgSn phases can effectively inhibit dislocation motion with the addition of Sn,thus increasing the peak fl ow stress of the alloy.The addition of Sn increases the hot deformation activation energy of the ZM61-0.5Ca alloy from 199.654 kJ/mol to 276.649 kJ/mol,thus improving the thermal stability of the alloy.For the ZMT612-0.5Ca alloy,the optimal hot deformation parameters are determined to be a deformation temperature range of 350–400℃and a strain rate range of 0.001–0.01 s^(-1). 展开更多
关键词 hot deformation constitutive equation processing map deformation activation energy magnesium alloy
原文传递
Optimization of Reaming Process and Design of Winding Motion Control for Type IV Composite Hydrogen Storage Cylinder
2
作者 SONG Junze LÜHongzhan 《Journal of Donghua University(English Edition)》 2026年第1期152-161,共10页
In order to optimize the reaming process of the type IV composite hydrogen storage cylinder,the netting theory was employed for the design of stacking sequences,and the thickness in the head section was predicted.A fi... In order to optimize the reaming process of the type IV composite hydrogen storage cylinder,the netting theory was employed for the design of stacking sequences,and the thickness in the head section was predicted.A finite element model of the plastic-lined composite hydrogen storage cylinder,designed to withstand a working pressure of 70.0 MPa,was established by using the wound composite modeler(WCM)in the Abaqus software to analyze the forces acting on the winding layer.The Hashin failure criterion was utilized as the standard for assessing composite failure,and a progressive failure analysis of the cylinder was conducted to predict both the bursting pressure and the failure location of the composite hydrogen storage cylinder.The results indicate that the reaming process can effectively reduce the maximum filament winding thickness in the head section and promote a more uniform transition.At the bursting pressure,the stress within the head liner decreases,thereby enhancing the ultimate bearing capacity of the cylinder.A control system for a four-axis winding machine was designed by utilizing an industrial computer and a programmable multi-axis controller(PMAC).The winding line pattern is designed and the G-code trajectory is generated by the industrial computer.The numerical control system,composed of the PMAC and servo motor,executes the four-axis interpolation motion. 展开更多
关键词 filament winding reaming process motion control progressive failure thickness prediction
在线阅读 下载PDF
Preparation Process and Performance Evaluation of Terminal Blend Composite-modified Asphalt
3
作者 YUAN Yan WANG Yefei +2 位作者 CHEN Hongyu XU Song ZHENG Zhidong 《Journal of Wuhan University of Technology(Materials Science)》 2026年第1期200-209,共10页
To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt b... To explore the best preparation process for terminal blend(TB)composite-modified asphalt and to filter its formulation with excellent performance,this study evaluates the performance of TB composite modified asphalt by physical property index,microscopic morphology,rheological testing,and infrared spectroscopy on multiple scales.The results show that the best preparation process for TB-modified asphalt is stirring at 260℃ for 4 h at 400 rpm,which significantly reduces the modification time of the asphalt.From a physical property viewpoint,the TB composite-modified asphalt sample with 5% styrene-butadiene-styrene(SBS)+1% aromatics+0.1% sulfur exhibits high-comprehensive,high-and low-temperature properties.More-over,its crosslinked mesh structure comprises black rubber particles uniformly interwoven in the middle,which further enhances the performance of the asphalt and results in an excellent performance formulation.In addition,the sample with 5%SBS content has a higher G*value and smaller δ value than that with 3%SBS content,indicating that its high-temperature resistance is improved.The effect of adding 3%SBS content on the viscoelastic ratio is,to some extent,less than that caused by 20% rubber powder. 展开更多
关键词 road engineering terminal blend rubberized asphalt preparation process modification mechanism
原文传递
Simulation Analysis of the Extrusion Process for Complex Cross-Sectional Profiles of Ultra-High Strength AluminumAlloy
4
作者 Tianxia Zou Yilin Sun +3 位作者 Fuhao Fan Zhen Zheng Yanjin Xu Baoshuai Han 《Computers, Materials & Continua》 2026年第4期471-491,共21页
Ultra-high-strength aluminumalloy profile is an ideal choice for aerospace structuralmaterials due to its excellent specific strength and corrosion resistance.However,issues such as uneven metal flow,stress concentrat... Ultra-high-strength aluminumalloy profile is an ideal choice for aerospace structuralmaterials due to its excellent specific strength and corrosion resistance.However,issues such as uneven metal flow,stress concentration,and forming defects are prone to occur during their extrusion.This study focuses on an Al-Zn-Mg-Cu ultra-high-strength aluminum alloy profile with a double-U,multi-cavity thin-walled structure.Firstly,hot compression experiments were conducted at temperatures of 350○C,400○C,and 450○C,with strain rates of 0.01 and 1.0 s^(−1),to investigate the plastic deformation behavior of the material.Subsequently,a 3D coupled thermo-mechanical extrusion simulation model was established using Deform-3D to systematically analyze the influence of die structure and process parameters on metal flow velocity,effective stress/strain,and temperature distribution.The simulation revealed significant velocity differences,stress concentration,and uneven temperature distribution.Key parameters,including mesh density,extrusion ratio,die fillet,and bearing length,were optimized through full-factorial experiments.This optimization,combined with a stepped flow-guiding die design,effectively improved the metal flow pattern during extrusion.Trial production based on both the initial and optimized parameters were carried out.A comparative analysis demonstrates that the optimized scheme results in a final profile whose cross-section matches the target design closely,with complete filling of complex features and no obvious forming defects.This research provides a valuable reference for the extrusion process optimization and die design of complex-section profiles made from ultra-high-strength aluminum alloys. 展开更多
关键词 Ultra-high-strength aluminum alloy EXTRUSION complex cross-section die optimization process optimization
在线阅读 下载PDF
Multi-pass intermittent local loading process of large-scale rib-web component:Forming characteristics and implementing apparatus
5
作者 Dawei ZHANG Peng DONG +2 位作者 Jingxiang LI Zijian YU Shengdun ZHAO 《Chinese Journal of Aeronautics》 2026年第1期601-625,共25页
The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and redu... The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption. 展开更多
关键词 Forming characteristics Hydraulic system Intermittent local loading process Material flow Rib-web component
原文传递
Could Increasing Minimally Processed Food Consumption Lower Body Fat Mass?
6
作者 Zhenyu Yang 《Biomedical and Environmental Sciences》 2026年第1期1-2,共2页
Overweight and obesity has been a major public health problem globally.It was estimated that more than 2.1 billion adults were affected by overweight or obese in 2021 worldwide,about one fifth of whom lived in China^(... Overweight and obesity has been a major public health problem globally.It was estimated that more than 2.1 billion adults were affected by overweight or obese in 2021 worldwide,about one fifth of whom lived in China^([1]).By 2050,the country is forecast to remain the one with the largest population of overweight and obese globally^([1]),if no effective strategies were applied on overweight/obesity control. 展开更多
关键词 OBESITY public health minimally processed food body fat mass OVERWEIGHT global health China overweight obesity
暂未订购
A peridynamics modeling approach for pre-cracked rock cracking processes under impact by integrating Drucker-Prager plasticity model and efficient contact model
7
作者 Jingzhi Tu Nengxiong Xu Gang Mei 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期179-195,共17页
In rock engineering,natural cracks in rock masses subjected to external loads tend to initiate and propagate,leading to potential safety hazards.To investigate the effect of cracking behavior on the mechanical propert... In rock engineering,natural cracks in rock masses subjected to external loads tend to initiate and propagate,leading to potential safety hazards.To investigate the effect of cracking behavior on the mechanical properties of rocks,the cracking processes of pre-cracked rocks have been extensively studied using numerical modeling methods.The peridynamics(PD)exhibits advantages over other numerical methods due to the absence of the requirements for remeshing and external crack growth criterion.However,for modeling pre-cracked rock cracking processes under impact,current PD implementations lack generally applicable rock constitutive models and impact contact models,which leads to difficulties in determining rock material parameters and efficiently calculating impact loads.This paper proposes a non-ordinary state-based peridynamics(NOSBPD)modeling method integrating the Drucker-Prager(DP)plasticity model and an efficient contact model to address the above problems.In the proposed method,the Drucker-Prager plasticity model is integrated into the NOSBPD,thereby equipping NOSBPD with the capability to accurately characterize the nonlinear stress-strain relationship inherent in rocks.An efficient contact model between particles and meshes is designed to calculate the impact loads,which is essentially a coupling method of PD with the finite element method(FEM).The effectiveness of the proposed NOSBPD modeling method is verified by comparison with other numerical methods and experiments.Experimental results indicate that the proposed method can effectively and accurately predict the 3D cracking processes of pre-cracked cracks under impact loading,and the maximum principal stress is the key driver behind wing crack formation in pre-cracked rocks. 展开更多
关键词 Pre-cracked rocks Cracking processes Non-ordinary state-based peridynamics (NOSBPD) Drucker-Prager plasticity model Efficient contact model
在线阅读 下载PDF
Tailoring oxygen vacancies in Ni-doped In_(2)O_(3) for improved thin-film transistor stability and performance via solution processing
8
作者 Fakhari Alam Sara Ajmal +3 位作者 Muhammad Asim Shahzad Ghulam Dastgeer Aamir Rasheed Gang He 《Journal of Semiconductors》 2026年第2期61-71,共11页
Doping in thin-film transistors(TFTs) plays a crucial role in tailoring material properties to enhance device performance, making them essential for advanced electronic applications. This study explores the synthesis ... Doping in thin-film transistors(TFTs) plays a crucial role in tailoring material properties to enhance device performance, making them essential for advanced electronic applications. This study explores the synthesis and characterization of TFTs fabricated using nickel(Ni)-doped indium oxide(In_(2)O_(3)) via a wet-chemical approach. The presented work investigates the effect of "Ni" incorporation in In_(2)O_(3) on the structural and electrical transport properties of In_(2)O_(3), revealing that higher "Ni" content decreases the oxygen vacancies, leading to a reduction in leakage current and a forward shift in threshold potential(V_(th)).Experimental findings reveal that Ni In O-based TFTs(with Ni = 0.5%) showcase enhanced electrical performance, achieving mobility of 7.54 cm^(2)/(V·s), an impressive ON/OFF current ratio of ~10^(7), a V_(th) of 6.26 V, reduced interfacial trap states(D_(it)) of 8.23 ×10^(12) cm^(-2) and enhanced biased stress stability. The efficacy of "Ni" incorporation is attributed to the upgraded Lewis acidity, stable Ni-O bond strength, and small ionic radius of Ni. Negative bias illumination stability(NBIS) measurements further indicate that device stability diminishes with shorter light wavelengths, likely due to the activation of oxygen vacancies. These findings validate the solution-processed techniques' potential for future large-scale, low-cost, energy-efficient, and high-performance electronics. 展开更多
关键词 thin-film transistors Ni-doped In_(2)O_(3) solution processing bias illumination stability
在线阅读 下载PDF
An Integrated Approach to Condition-Based Maintenance Decision-Making of Planetary Gearboxes: Combining Temporal Convolutional Network Auto Encoders with Wiener Process
9
作者 Bo Zhu Enzhi Dong +3 位作者 Zhonghua Cheng Xianbiao Zhan Kexin Jiang Rongcai Wang 《Computers, Materials & Continua》 2026年第1期661-686,共26页
With the increasing complexity of industrial automation,planetary gearboxes play a vital role in largescale equipment transmission systems,directly impacting operational efficiency and safety.Traditional maintenance s... With the increasing complexity of industrial automation,planetary gearboxes play a vital role in largescale equipment transmission systems,directly impacting operational efficiency and safety.Traditional maintenance strategies often struggle to accurately predict the degradation process of equipment,leading to excessive maintenance costs or potential failure risks.However,existing prediction methods based on statistical models are difficult to adapt to nonlinear degradation processes.To address these challenges,this study proposes a novel condition-based maintenance framework for planetary gearboxes.A comprehensive full-lifecycle degradation experiment was conducted to collect raw vibration signals,which were then processed using a temporal convolutional network autoencoder with multi-scale perception capability to extract deep temporal degradation features,enabling the collaborative extraction of longperiod meshing frequencies and short-term impact features from the vibration signals.Kernel principal component analysis was employed to fuse and normalize these features,enhancing the characterization of degradation progression.A nonlinear Wiener process was used to model the degradation trajectory,with a threshold decay function introduced to dynamically adjust maintenance strategies,and model parameters optimized through maximum likelihood estimation.Meanwhile,the maintenance strategy was optimized to minimize costs per unit time,determining the optimal maintenance timing and preventive maintenance threshold.The comprehensive indicator of degradation trends extracted by this method reaches 0.756,which is 41.2%higher than that of traditional time-domain features;the dynamic threshold strategy reduces the maintenance cost per unit time to 55.56,which is 8.9%better than that of the static threshold optimization.Experimental results demonstrate significant reductions in maintenance costs while enhancing system reliability and safety.This study realizes the organic integration of deep learning and reliability theory in the maintenance of planetary gearboxes,provides an interpretable solution for the predictive maintenance of complex mechanical systems,and promotes the development of condition-based maintenance strategies for planetary gearboxes. 展开更多
关键词 Temporal convolutional network autoencoder full lifecycle degradation experiment nonlinear Wiener process condition-based maintenance decision-making fault monitoring
在线阅读 下载PDF
郭为与他的AI for Process
10
作者 姜奇平 端利涛 《互联网周刊》 2026年第2期8-12,共5页
一、作为哲学的AI for Process(一)郭为的哲学思想1.郭为是谁郭为是谁?他是一位哲学家。顺便说,他同时还领导着神州数码。为什么说郭为是哲学家呢?因为他在著作中谈到高深的哲学,如“数据如水,奔流不息,无界融合”。他引述古希腊哲学家... 一、作为哲学的AI for Process(一)郭为的哲学思想1.郭为是谁郭为是谁?他是一位哲学家。顺便说,他同时还领导着神州数码。为什么说郭为是哲学家呢?因为他在著作中谈到高深的哲学,如“数据如水,奔流不息,无界融合”。他引述古希腊哲学家赫拉克利特所说的“万物流转”,又说“你不能两次踏进同一条河流,因为新的水不断地流过你的身旁”,他所表达的意思是“世界上唯一不变的就是变化”。 展开更多
关键词 AI for process 郭为
在线阅读 下载PDF
MP 23S rRNA突变、LDH交互影响肺炎支原体肺炎患儿阿奇霉素响应性的效能及其预测价值
11
作者 段永彬 梁娟 +2 位作者 张敬芳 胡湘萍 张俊霞 《河南医学研究》 2026年第5期888-893,共6页
目的探讨肺炎支原体(MP)肺炎患儿MP 23S rRNA突变、乳酸脱氢酶(LDH)交互作用对阿奇霉素响应性的影响及其对阿奇霉素响应性的预测价值。方法选取2023年3月至2025年2月濮阳市人民医院收治的196例MP肺炎患儿,依据阿奇霉素响应性分为不良组... 目的探讨肺炎支原体(MP)肺炎患儿MP 23S rRNA突变、乳酸脱氢酶(LDH)交互作用对阿奇霉素响应性的影响及其对阿奇霉素响应性的预测价值。方法选取2023年3月至2025年2月濮阳市人民医院收治的196例MP肺炎患儿,依据阿奇霉素响应性分为不良组、良好组。比较两组临床资料及MP 23S rRNA突变、LDH水平。多因素logistic回归分析MP 23S rRNA突变、LDH对阿奇霉素响应性的影响效应。交互作用分析MP 23S rRNA突变、LDH对阿奇霉素响应性的交互影响效应。采用受试者工作特征(ROC)曲线及曲线下面积(AUC)分析MP 23S rRNA突变、LDH对阿奇霉素响应性的预测价值。结果196例MP肺炎患儿中阿奇霉素响应性不良47例(23.98%)、良好149例(76.02%);不良组MP 23S rRNA突变占比、LDH水平高于良好组,差异有统计学意义(P<0.05);多因素logistic回归分析显示,MP 23S rRNA突变、LDH均是阿奇霉素响应性的相关影响因素(P<0.05);根据MP 23S rRNA突变、LDH将全部对象分为MP 23S rRNA无突变+LDH正常水平(R_(00))、MP 23S rRNA无突变+LDH升高(R_(01))、MP 23S rRNA突变+LDH正常水平(R_(10))、MP 23S rRNA突变+LDH升高(R_(01))4个亚组,以R_(00)为参照,R_(01)、R_(10)、R_(01)可将阿奇霉素响应不良风险提高1.139倍、2.709倍、5.332倍(P<0.05);MP 23S rRNA突变联合LDH预测阿奇霉素响应性的AUC值为0.949,大于单独的MP 23S rRNA突变的0.872、LDH的0.776(P<0.05)。结论MP肺炎阿奇霉素响应性不良患儿MP 23S rRNA突变占比、LDH水平较良好患儿明显升高,且MP 23S rRNA突变、LDH对阿奇霉素响应性具有正向相加交互效应,联合检测其水平可用于早期预测阿奇霉素响应性,为临床个体化治疗提供决策依据。 展开更多
关键词 肺炎支原体 肺炎支原体肺炎 mp 23S rRNA 突变 乳酸脱氢酶 交互影响 预测
暂未订购
Buoyancy characteristic analysis and optimization of precast concrete slab track during casting process of self-compacting concrete 被引量:1
12
作者 Pengsong Wang Tao Xin +2 位作者 Peng Chen Sen Wang Di Cheng 《Railway Sciences》 2025年第2期159-173,共15页
Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of prec... Purpose–The precast concrete slab track(PST)has advantages of fewer maintenance frequencies,better smooth rides and structural stability,which has been widely applied in urban rail transit.Precise positioning of precast concrete slab(PCS)is vital for keeping the initial track regularity.However,the cast-in-place process of the self-compacting concrete(SCC)filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC,even cracking of PCS.Currently,the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.Design/methodology/approach–In this work,a Computational Fluid Dynamics(CFD)model is established to calculate the buoyancy of PCS caused by the flowing SCC.The main influencing factors,including the inlet speed and flowability of SCC,have been analyzed and discussed.A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.Findings–The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.Originality/value–The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process. 展开更多
关键词 Casting process Buoyancy characteristics Precast concrete slab track SIMULATION Field test OPTIMIZATION
在线阅读 下载PDF
Numerical calculation of bottom hole circulating temperature in wellbore cementing processes with multi-fluid and multi-step 被引量:1
13
作者 Xu-Ning Wu Zheng-Meng Hou +5 位作者 Zao-Yuan Li Bo Feng Lin Wu Qian-Jun Chen Nan Cai Ting-Cong Wei 《Petroleum Science》 2025年第4期1578-1595,共18页
In oil and gas well cementing processes,accurately predicting the bottom hole circulating temperature(BHCT)is critical to ensuring effective zonal isolation.Overestimating the temperature can lead to excessive retarda... In oil and gas well cementing processes,accurately predicting the bottom hole circulating temperature(BHCT)is critical to ensuring effective zonal isolation.Overestimating the temperature can lead to excessive retardation issues,while underestimation can cause cementing accidents.Current methods for calculating the BHCT of cement slurry typically simplify the cementing processes to a single-fluid circulation and ignore the impact of pre-cementing processes on temperature,leading to significant discrepancies between calculated and actual results.In this study,the wellbore and formation are simplified into a two-dimensional axisymmetric structure,and a mathematical model of the temperature field under multi-fluid and multi-step conditions is established based on the law of energy conservation.The finite volume method was used to discretize the model,and a transient temperature field solver for the entire cementing process was developed,which can numerically calculate the temperature of any fluid at any time,any location.For an actual well example,the temperature distribution of the wellbore and formation after casing running is taken as the initial condition.Numerical calculations were performed sequentially to calculate the temperature fields of circulation flushing,wellbore preparation,and cementing,as well as the BHCT of the cement slurry.The study reveals that during the circulation flushing stage,the maximum temperature point in the wellbore is located at a distance of about 366 m above the bottom of the well.In the wellbore preparation stage,due to static heat exchange,the maximum temperature point gradually shifts to the bottom of the well.The BHCT of cement slurry changes continuously under cementing processes with multi-fluid and multi-step,making it a transient value.The BHCT of the lead slurry and tail slurry are not equal,with the maximum BHCT of the tail slurry being 2.46°C higher than that of the lead slurry.If circulation flushing and wellbore preparation are not considered,the calculated BHCT of the cement slurry will have errors of+6.8%and-1.9%.The study highlighted that considering thermal effects of all cementing stages,such as circulation flushing and wellbore preparation,in BHCT calculations can help improve prediction accuracy. 展开更多
关键词 Cementing processes Bottom hole circulating temperature Multi-fluid injection Transient temperature field
原文传递
Relative vacuum reduction innovative processes applied in primary magnesium production-Comprehensive analysis of thermodynamics,resource,energy flow,and carbon emission 被引量:1
14
作者 Xiaolong Li Tingan Zhang +3 位作者 Yan Liu Junhua Guo Jingzhong Xu Yuanyuan Liang 《Journal of Magnesium and Alloys》 2025年第7期3134-3149,共16页
Magnesium and magnesium alloys,serving as crucial lightweight structural materials and hydrogen storage elements,find extensive applications in space technology,aviation,automotive,and magnesium-based hydrogen industr... Magnesium and magnesium alloys,serving as crucial lightweight structural materials and hydrogen storage elements,find extensive applications in space technology,aviation,automotive,and magnesium-based hydrogen industries.The global production of primary magnesium has reached approximately 1.2 million tons per year,with anticipated diversification in future applications and significant market demand.Nevertheless,approximately 80%of the world’s primary magnesium is still manufactured through the Pidgeon process,grappling with formidable issues including high energy consumption,massive carbon emission,significant resource depletion,and environmental pollution.The implementation of the relative vacuum method shows potential in breaking through technological challenges in the Pidgeon process,facilitating clean,low-carbon continuous magnesium smelting.This paper begins by introducing the principles of the relative vacuum method.Subsequently,it elucidates various innovative process routes,including relative vacuum ferrosilicon reduction,aluminum thermal reduction co-production of spinel,and aluminum thermal reduction co-production of calcium aluminate.Finally,and thermodynamic foundations of the relative vacuum,a quantitative analysis of the material,energy flows,carbon emission,and production cost for several new processes is conducted,comparing and analyzing them against the Pidgeon process.The study findings reveal that,with identical raw materials,the relative vacuum silicon thermal reduction process significantly decreases raw material consumption,energy consumption,and carbon dioxide emissions by 15.86%,30.89%,and 26.27%,respectively,compared to the Pidgeon process.The relative vacuum process,using magnesite as the raw material and aluminum as the reducing agent,has the lowest magnesium-to-feed ratio,at only 3.385.Additionally,its energy consumption and carbon dioxide emissions are the lowest,at 1.817 tce/t Mg and 7.782 t CO_(2)/t Mg,respectively.The energy consumption and carbon emissions of the relative vacuum magnesium smelting process co-producing calcium aluminate(12CaO·7Al_(2)O_(3),3CaO·Al_(2)O_(3),and CaO·Al_(2)O_(3))are highly correlated with the consumption of dolomite in the raw materials.When the reduction temperature is around 1473.15 K,the critical volume fraction of magnesium vapor for different processes varies within the range of 5%–40%.Production cost analysis shows that the relative vacuum primary magnesium smelting process has significant economic benefits.This paper offers essential data support and theoretical guidance for achieving energy efficiency,carbon reduction in magnesium smelting,and the industrial adoption of innovative processes. 展开更多
关键词 Magnesium smelting Relative vacuum reduction process THERMODYNAMICS Resource and energy flow Carbon emission
在线阅读 下载PDF
A Composite Structure of Al–Mg–Sc Alloy Prepared by Wire Arc‑Directed Energy Deposition with Interlayer Friction Stir Processing 被引量:1
15
作者 Y.P.Cui X.P.Guo +4 位作者 P.Xue R.Z.Xu X.M.Guo D.R.Ni Z.Y.Ma 《Acta Metallurgica Sinica(English Letters)》 2025年第10期1794-1808,共15页
Interlayer friction stir processing(FSP)has been proved to be an efective method of enhancing the mechanical properties of wire arc-directed energy deposited(WA-DED)samples.However,the original deposition structure wa... Interlayer friction stir processing(FSP)has been proved to be an efective method of enhancing the mechanical properties of wire arc-directed energy deposited(WA-DED)samples.However,the original deposition structure was still retained in the FSP-WA-DED component besides the processed zone(PZ),thus forming a composite structure.Considering the material utilization and practical service process of the deposited component,more attention should be paid on this special composite structure,but the relevant investigation has not been carried out.In this study,an Al–Mg–Sc alloy was prepared by WA-DED with interlayer FSP treatment,and the composite structure was frstly investigated.Almost all of the pores were eliminated under the pressure efect from the tool shoulder.The grains were further refned with an average size of about 1.2μm in the PZ.Though no severe plastic deformation was involved in the retained WA-DED deposition zone,comparable tensile properties with the PZ sample were obtained in the composite structure.Low ultimate tensile strength(UTS)of 289 MPa and elongation of 3.2%were achieved in the WA-DED sample.After interlayer FSP treatment,the UTS and elongation of the PZ samples were signifcantly increased to 443 MPa and 16.3%,while those in the composite structure remained at relatively high levels of 410 MPa and 13.5%,respectively.Meanwhile,a high fatigue strength of 180 and 130 MPa was obtained in the PZ and composite structure samples,which was clearly higher than that of the WA-DED sample(100 MPa).It is concluded that the defects in traditional WA-DED process can be eliminated in the composite structure after interlayer FSP treatment,resulting in enhanced tensile and fatigue properties,which provides an efective method of improving the mechanical properties of the WA-DED sample. 展开更多
关键词 Wire arc-directed energy deposition Al-Mg-Sc alloys Friction stir processing Composite structure Mechanical property
原文传递
Optimization of Surface Layer Properties of Mg-9Li-1Zn Alloy by Ultrasonic Surface Rolling Process and its Impact on Corrosion Behavior 被引量:1
16
作者 Huimin Yang Kun Yang +1 位作者 Guobing Wei Rongguang Li 《Acta Metallurgica Sinica(English Letters)》 2025年第8期1421-1435,共15页
The Mg-9Li-1Zn(LZ91)alloy was subjected to an ultrasonic surface rolling process(USRP)with varying passes for the purpose of modifying its surface state.The USRP transformed surface residual stress from initial tensil... The Mg-9Li-1Zn(LZ91)alloy was subjected to an ultrasonic surface rolling process(USRP)with varying passes for the purpose of modifying its surface state.The USRP transformed surface residual stress from initial tensile stress to compressive stress,decreasing the surface roughness and increasing the ratio of the β-Li phase.The USRPed LZ91 sample(3 passes)showed superior corrosion resistance,with the corrosion current density changing from 57.11 to 24.70μA cm^(-2),and the polarization resistance increasing from 576.3 to 1146.1Ωcm^(2).According to the corrosion procedure evaluations,in situ observation revealed that the LZ91 alloy initially experiences pitting,which subsequently develops into cracking.The substantial area coverage of the β-Li phase facilitates the formation of a protective film on the surface,effectively delaying localized corrosion. 展开更多
关键词 Dual-phase Mg-Li alloy Ultrasonic surface rolling process Oxide film Local corrosion Compressive residual stress
原文传递
Multi-objective optimization of grinding process parameters for improving gear machining precision 被引量:1
17
作者 YOU Tong-fei HAN Jiang +4 位作者 TIAN Xiao-qing TANG Jian-ping LU Yi-guo LI Guang-hui XIA Lian 《Journal of Central South University》 2025年第2期538-551,共14页
The gears of new energy vehicles are required to withstand higher rotational speeds and greater loads,which puts forward higher precision essentials for gear manufacturing.However,machining process parameters can caus... The gears of new energy vehicles are required to withstand higher rotational speeds and greater loads,which puts forward higher precision essentials for gear manufacturing.However,machining process parameters can cause changes in cutting force/heat,resulting in affecting gear machining precision.Therefore,this paper studies the effect of different process parameters on gear machining precision.A multi-objective optimization model is established for the relationship between process parameters and tooth surface deviations,tooth profile deviations,and tooth lead deviations through the cutting speed,feed rate,and cutting depth of the worm wheel gear grinding machine.The response surface method(RSM)is used for experimental design,and the corresponding experimental results and optimal process parameters are obtained.Subsequently,gray relational analysis-principal component analysis(GRA-PCA),particle swarm optimization(PSO),and genetic algorithm-particle swarm optimization(GA-PSO)methods are used to analyze the experimental results and obtain different optimal process parameters.The results show that optimal process parameters obtained by the GRA-PCA,PSO,and GA-PSO methods improve the gear machining precision.Moreover,the gear machining precision obtained by GA-PSO is superior to other methods. 展开更多
关键词 worm wheel gear grinding machine gear machining precision machining process parameters multi objective optimization
在线阅读 下载PDF
Design method of civil aircraft based on MBSE with improved process model
18
作者 Yunong WANG An ZHANG +2 位作者 Wenhao BI Yanlong HAN Haomin LI 《Chinese Journal of Aeronautics》 2025年第12期192-213,共22页
With the raising complexity of modern civil aircraft,both academy and industry have shown strong interests on MBSE(Model-Based System Engineering).However,following the application of MBSE,the duration of the design p... With the raising complexity of modern civil aircraft,both academy and industry have shown strong interests on MBSE(Model-Based System Engineering).However,following the application of MBSE,the duration of the design phase exceeded expectations.This paper conducted a survey to the relevant participants involved in the design,revealed that a lack of proper process management is a critical issue.The current MBSE methodology does not provide clear guidelines for monitoring,controlling,and managing processes,which are crucial for both efficiency and effectiveness.To address this,the present paper introduced an improved Process Model(PM)within the MBSE framework for civil aircraft design.This improved model incorporates three new Management Blocks(MB):Progress Management Block(PMB),Review Management Block(RMB),and Configuration Management Block(CMB),developed based on the Capability Maturity Model Integration(CMMI).These additions aim to streamline the design process and better align it with engineering practices.The upgraded MBSE method with the improved PM offers a more structured approach to manage complex aircraft design projects,and a case study is conducted to validate its potential to reduce timelines and enhance overall project outcomes. 展开更多
关键词 Capability Maturity Model Integration(CMMI) Civil aviation Design method MBSE process engineering process Model(PM)
原文传递
Explicit ARL Computational for a Modified EWMA Control Chart in Autocorrelated Statistical Process Control Models
19
作者 Yadpirun Supharakonsakun Yupaporn Areepong Korakoch Silpakob 《Computer Modeling in Engineering & Sciences》 2025年第10期699-720,共22页
This study presents an innovative development of the exponentially weighted moving average(EWMA)control chart,explicitly adapted for the examination of time series data distinguished by seasonal autoregressive moving ... This study presents an innovative development of the exponentially weighted moving average(EWMA)control chart,explicitly adapted for the examination of time series data distinguished by seasonal autoregressive moving average behavior—SARMA(1,1)L under exponential white noise.Unlike previous works that rely on simplified models such as AR(1)or assume independence,this research derives for the first time an exact two-sided Average Run Length(ARL)formula for theModified EWMAchart under SARMA(1,1)L conditions,using a mathematically rigorous Fredholm integral approach.The derived formulas are validated against numerical integral equation(NIE)solutions,showing strong agreement and significantly reduced computational burden.Additionally,a performance comparison index(PCI)is introduced to assess the chart’s detection capability.Results demonstrate that the proposed method exhibits superior sensitivity to mean shifts in autocorrelated environments,outperforming existing approaches.The findings offer a new,efficient framework for real-time quality control in complex seasonal processes,with potential applications in environmental monitoring and intelligent manufacturing systems. 展开更多
关键词 Statistical process control average run length modified EWMA control chart autocorrelated data SARMA process computational modeling real-time monitoring
在线阅读 下载PDF
Proteomic studies of the effects of processing techniques on properties of abalone muscles:a comprehensive review
20
作者 Yan Tian Shuyi You +2 位作者 Yi Zhang Baodong Zheng Hongliang Zeng 《Food Science and Human Wellness》 2025年第11期4351-4362,共12页
With the increasing per capita demand for animal protein,there is a growing interest in the abundant abalone protein resources.Abalone proteins are known for their nutritional and functional properties that contribute... With the increasing per capita demand for animal protein,there is a growing interest in the abundant abalone protein resources.Abalone proteins are known for their nutritional and functional properties that contribute to flavor and texture.We systematically constructed the relationship between abalone protein,processing,and proteomics.This paper reviews the nutritional properties of abalone proteins and evaluates the effects of different thermal processing techniques,non-thermal processing,and freezing on abalone proteins.In addition,we synthesize published abalone proteomics studies and the use of proteomics technology to better elucidate the quality changes of abalone and its products,and as a technical basis for the study of blue food marker proteins.It is important direction to clearly explain the protein composition and meat quality mechanism of abalone in the processing and storage by proteomic.During various types of thermal processing,non-thermal processing,and freezing of abalone,the various chemical forces between protein molecules are disrupted,which in turn leads to different degrees of denaturation,aggregation,and gelation,which may have an impact on the organoleptic properties,bioavailability,and digestibility of abalone muscle.Proteomics is used in abalone biology studies to understand developmental biology,physiology,disease,stress,and species identification and can also be a powerful tool to characterize processing methods on abalone quality properties. 展开更多
关键词 ABALONE PROTEIN process Quality characteristics PROTEOMICS
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部