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Ultrasonic vibration-assisted cutting of titanium alloys:A state-of-the-art review 被引量:3
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作者 Ahmar KHAN Xin WANG +7 位作者 Biao ZHAO Wenfeng DING Muhammad JAMIL Aqib Mashood KHAN Syed Hammad ALI Sadam HUSSAIN Jiong ZHANG Raj DAS 《Chinese Journal of Aeronautics》 2025年第1期3-42,共40页
The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and med... The remarkable ability of titanium alloys to preserve their superior physical and chemical characteristics when subjected to extreme conditions significantly enhances their importance in the aerospace,military,and medical sectors.However,conventional machining of titanium alloys leads to elevated tool wear,development of surface defects,and reduced machining efficiency due to their low heat conductivity,and chemical affinity.These issues can be somewhat counteracted by integrating ultrasonic vibration in the conventional machining of titanium alloys and also enhance sustainability.This review article offers a holistic evaluation of the influence of ultrasonic vibration-assisted milling and turning on cutting forces,temperature,tool wear,and surface integrity,encompassing surface morphology,surface roughness,surface residual stress,surface hardness,and surface tribological properties during titanium alloys machining.Furthermore,it investigates the sustainability aspect that has not been previously examined.Studies on the performance of ultrasonic-assisted cutting revealed several advantages,including decreased cutting forces and cutting temperature,improved tool life,and a better-machined surface during machining.Consequently,the sustainability factor is improved due to minimized energy consumption and residual waste.In conclusion,the key challenges and future prospects in the ultrasonic-assisted cutting of titanium alloys are also discussed.This review article provides beneficial knowledge for manufactur-ers and researchers regarding ultrasonic vibration-assisted cutting of titanium alloy and will play an important role in achieving sustainability in the industry. 展开更多
关键词 Ultrasonic vibration-assisted cutting Titanium alloys Material removal mechanism MACHINABILITY SUSTAINABILITY
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From crack-prone to crack-free:Eliminating cracks in additively manufacturing of high-strength Mg_(2)Si-modified Al-Mg-Si alloys 被引量:3
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作者 Tao Wen Zhicheng Li +6 位作者 Jianying Wang Yimou Luo Feipeng Yang Zhilin Liu Dong Qiu Hailin Yang Shouxun Ji 《Journal of Materials Science & Technology》 2025年第1期276-291,共16页
Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification.In this work,we develop novel crack-free Al-Mg_(2) Si... Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification.In this work,we develop novel crack-free Al-Mg_(2) Si alloys fabricated by laser powder-bed fusion(L-PBF).The results indicate that the eutectic Mg_(2) Si phase possesses a strong ability to reduce crack susceptibility.It can enhance the grain growth restriction factor in the initial stage of solidification and promote eutectic filling in the terminal stage of solidifica-tion.The crack-free L-PBFed Al-x Mg_(2) Si alloys(x=6 wt.%,9 wt.%,and 12 wt.%)exhibit the combination of low crack susceptibility index(CSI),superior ability for liquid filling,and grain refinement.Particularly,the L-PBFed Al-9Mg_(2) Si alloy shows improved mechanical properties(e.g.yield strength of 397 MPa and elongation of 7.3%).However,the cracks are more likely to occur in the region near the columnar grain boundaries of the L-PBFed Al-3Mg_(2) Si alloy with a large solidification range and low eutectic content for liquid filling.Correspondingly,the L-PBFed Al-3Mg_(2) Si alloy shows poor bearing capacity of mechanical properties.The precise tuning of Mg_(2) Si eutectic content can offer an innovative strategy for eliminating cracks in additively manufactured Al-Mg-Si alloy. 展开更多
关键词 Aluminium alloys Las powder-bed fusion Crack elimination Mechanical properties
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Ferroelectric domain engineering of Lithium niobate 被引量:1
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作者 Jackson J.Chakkoria Aditya Dubey +1 位作者 Arnan Mitchell Andreas Boes 《Opto-Electronic Advances》 2025年第2期46-79,共34页
Lithium niobate(LN)has remained at the forefront of academic research and industrial applications due to its rich material properties,which include second-order nonlinear optic,electro-optic,and piezoelectric properti... Lithium niobate(LN)has remained at the forefront of academic research and industrial applications due to its rich material properties,which include second-order nonlinear optic,electro-optic,and piezoelectric properties.A further aspect of LN’s versatility stems from the ability to engineer ferroelectric domains with micro and even nano-scale precision in LN,which provides an additional degree of freedom to design acoustic and optical devices with improved performance and is only possible in a handful of other materials.In this review paper,we provide an overview of the domain engineering techniques developed for LN,their principles,and the typical domain size and pattern uniformity they provide,which is important for devices that require high-resolution domain patterns with good reproducibility.It also highlights each technique's benefits,limitations,and adaptability for an application,along with possible improvements and future advancement prospects.Further,the review provides a brief overview of domain visualization methods,which is crucial to gain insights into domain quality/shape and explores the adaptability of the proposed domain engineering methodologies for the emerging thin-film lithium niobate on an insulator platform,which creates opportunities for developing the next generation of compact and scalable photonic integrated circuits and high frequency acoustic devices. 展开更多
关键词 lithium niobate FERROELECTRIC domain engineering lithium niobate on insulator domain visualization periodic poling quasi-phase matching acoustic
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Kirkendall effect-assisted electrospinning porous FeCo/Zn@C nanofibers featuring well-dispersed FeCo nanoparticles for ultra-wide electromagnetic wave absorption 被引量:1
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作者 Qi-Hui Sun Hao-Cheng Zhai +4 位作者 Yi-Fan Liu Chun-Sheng Li Jun-Wei Wang Xian Jian Nasir Mahmood 《Rare Metals》 2025年第3期1856-1868,共13页
Ultra-wide absorption band and flexibility are needed in multi-scenario applications,however,current electromagnetic wave absorption materials(EMWAMs)are not capable enough to deliver due to rigid structure.Here,we ha... Ultra-wide absorption band and flexibility are needed in multi-scenario applications,however,current electromagnetic wave absorption materials(EMWAMs)are not capable enough to deliver due to rigid structure.Here,we have designed a porous flexible mat composed of Zn-doped carbon(Zn@C)nanofibers(NFs)having encapsulated uniformly dispersed FeCo nanoparticles(NPs)(FeCo/Zn@C)as ultra-wideband absorber.During the electrospinning,the Fe^(3+),Co^(2+)and Zn^(2+)are uniformly immobilized within the NFs nanocrystallization process.Subsequently,the Kirkendall effect is deployed to trigger the generation of FeCo NPs and porous framework under thermal annealing.The FeCo/Zn@C NFs effectively favor magnetic-dielectric synergies due to the coexistence of magnetic FeCo NPs and dielectric carbon components.One-dimensional porous fiber prolongs the attenuation path and enhances multi-scattering and reflection.While the FeCo NPs encapsulated in Zn-doped carbon NFs provide abundant dipole and interfacial polarization.These favorable factors synergistically enhance absorption performance,resulting in a reflection loss value of-71.58 dB.Moreover,by varying the thickness of absorbers,effective absorption bandwidth spans from 4.26 to 18.00 GHz.Hence,this work offers innovative insights for fabricating advanced EMWAMs. 展开更多
关键词 FeCo nanoparticles Multi-interface structure Flexible mat Electromagnetic wave absorption
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Characterization and correlation of engineering properties with microstructure in peanuts:A microscopic to macroscopic analysis 被引量:1
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作者 Fei Xiang Zhenyuan Li +9 位作者 Yichen Zheng Caixia Ding Benu Adhikari Xiaojie Ma Xuebing Xu Jinjin Zhu Bello Zaki Abubakar Aimin Shi Hui Hu Qiang Wang 《Journal of Integrative Agriculture》 2025年第1期339-352,共14页
Peanut varieties are diverse globally,with their characters and nutrition determining the product quality.However,the comparative analysis and statistical analysis of key quality indicators for peanut kernels across t... Peanut varieties are diverse globally,with their characters and nutrition determining the product quality.However,the comparative analysis and statistical analysis of key quality indicators for peanut kernels across the world remains relatively limited,impeding the comprehensive evaluation of peanut quality and hindering the industry development on a global scale.This study aimed to compare and analyze the apparent morphology,microstructure,single-cell structure,engineering and mechanical properties,as well as major nutrient contents of peanut kernels from 10 different cultivars representing major peanut-producing countries.The surface and cross-section microstructure of the peanut kernels exhibited a dense“blocky”appearance with a distinct cellular structure.The lipid droplets were predominantly spherical with a regular distribution within the cells.The single-cell structure of the kernels from these 10 peanut cultivars demonstrated varying morphologies and dimensions,which exhibited correlations with their mechanical and engineering properties.Furthermore,the mass loss versus temperature profiles of the peanut kernels revealed five distinct stages,corresponding to moisture loss,volatile loss,protein denaturation,and the degradation of various biomacromolecules.Variations were also observed in the lipid,protein,and sucrose contents,texture,bulk density,true density,porosity,geometric mean diameter,and sphericity among the diferent peanut varieties.This study establishes relationships and correlations among microstructure,engineering properties,and nutritional composition of commonly grown peanut varieties in major peanut-processing countries.The findings provide valuable insights into peanut quality evaluation,empowering the peanut industry to enhance their processing and product development efforts. 展开更多
关键词 peanut kernels apparent morphology MICROSTRUCTURE engineering properties mechanical properties
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非均相催化CO_(2)与烃类协同催化转化的最新进展
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作者 张红红 魏振 +5 位作者 Derek Hao 敬林 刘雨溪 戴洪兴 魏伟钦 邓积光 《物理化学学报》 北大核心 2025年第7期44-64,共21页
在当今时代,全球极端天气事件呈现出愈发频繁的态势,过量温室气体排放是极为关键的诱因。二氧化碳(CO_(2))是最主要的温室气体之一,排放量逐年递增,迫使人们采取行之有效的行动以应对过量CO_(2)排放的影响和威胁。全球各国都在探索脱碳... 在当今时代,全球极端天气事件呈现出愈发频繁的态势,过量温室气体排放是极为关键的诱因。二氧化碳(CO_(2))是最主要的温室气体之一,排放量逐年递增,迫使人们采取行之有效的行动以应对过量CO_(2)排放的影响和威胁。全球各国都在探索脱碳技术以实现净零排放。从能源角度来说,CO_(2)是一种丰富且低成本的碳资源,其可通过与烃类化合物(如烷烃、烯烃、芳香烃和聚烯烃等)协同转化为高值化学品。通过氢转移,CO_(2)可被还原成CO,同时形成H_(2)O。通过CO_(2)和烃分子干重整,可转化为合成气(CO和H_(2))。此外,CO_(2)还可以插入烃分子,引起碳链增长,生成醇类、羧酸和芳烃等物种。然而,由于CO_(2)的热力学稳定性和动力学惰性,以及烃类中C―H键的键能较高和极性较小,CO_(2)和烃类的协同转化极具挑战。本综述重点介绍在非均相催化剂上协同催化CO_(2)和不同烃类增值转化的产物和反应效率的最新进展,探讨了CO_(2)和烃类转化中涉及的相关反应动力学模型(Langmuir-Hinshelwood和Eley-Rideal)。此外,设计具有不同活性位点的双功能催化剂可分别活化这两种反应分子,以及调控酸碱性、构筑氧空位和优化界面位点是增强催化性能的有效策略。最后,提出了CO_(2)与烃类共转化技术的未来发展方向,并对低碳发展战略提出了建议。 展开更多
关键词 二氧化碳 烃类 协同催化增值 增值化学品 非均相催化
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Molecular Structure Tailoring of Organic Spacers for High‑Performance Ruddlesden–Popper Perovskite Solar Cells
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作者 Pengyun Liu Xuejin Li +6 位作者 Tonghui Cai Wei Xing Naitao Yang Hamidreza Arandiyan Zongping Shao Shaobin Wang Shaomin Liu 《Nano-Micro Letters》 SCIE EI CAS 2025年第2期314-357,共44页
Layer-structured Ruddlesden–Popper(RP)perovskites(RPPs)with decent stability have captured the imagination of the photovoltaic research community and bring hope for boosting the development of perovskite solar cell(P... Layer-structured Ruddlesden–Popper(RP)perovskites(RPPs)with decent stability have captured the imagination of the photovoltaic research community and bring hope for boosting the development of perovskite solar cell(PSC)technology.However,two-dimensional(2D)or quasi-2D RP PSCs are encountered with some challenges of the large exciton binding energy,blocked charge transport and poor film quality,which restrict their photovoltaic performance.Fortunately,these issues can be readily resolved by rationally designing spacer cations of RPPs.This review mainly focuses on how to design the molecular structures of organic spacers and aims to endow RPPs with outstanding photovoltaic applications.We firstly elucidated the important roles of organic spacers in impacting crystallization kinetics,charge transporting ability and stability of RPPs.Then we brought three aspects to attention for designing organic spacers.Finally,we presented the specific molecular structure design strategies for organic spacers of RPPs aiming to improve photovoltaic performance of RP PSCs.These proposed strategies in this review will provide new avenues to develop novel organic spacers for RPPs and advance the development of RPP photovoltaic technology for future applications. 展开更多
关键词 Ruddlesden-Popper perovskites Low-dimensional perovskite solar cells Organic spacers Molecular structure Design strategies
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Explaining machine learning models trained to predict Copernicus DEM errors in different land cover environments
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作者 Michael Meadows Karin Reinke Simon Jones 《Artificial Intelligence in Geosciences》 2025年第2期113-130,共18页
Machine learning models are increasingly used to correct the vertical biases(mainly due to vegetation and buildings)in global Digital Elevation Models(DEMs),for downstream applications which need‘‘bare earth"el... Machine learning models are increasingly used to correct the vertical biases(mainly due to vegetation and buildings)in global Digital Elevation Models(DEMs),for downstream applications which need‘‘bare earth"elevations.The predictive accuracy of these models has improved significantly as more flexible model architectures are developed and new explanatory datasets produced,leading to the recent release of three model-corrected DEMs(FABDEM,DiluviumDEM and FathomDEM).However,there has been relatively little focus so far on explaining or interrogating these models,especially important in this context given their downstream impact on many other applications(including natural hazard simulations).In this study we train five separate models(by land cover environment)to correct vertical biases in the Copernicus DEM and then explain them using SHapley Additive exPlanation(SHAP)values.Comparing the models,we find significant variation in terms of the specific input variables selected and their relative importance,suggesting that an ensemble of models(specialising by land cover)is likely preferable to a general model applied everywhere.Visualising the patterns learned by the models(using SHAP dependence plots)provides further insights,building confidence in some cases(where patterns are consistent with domain knowledge and past studies)and highlighting potentially problematic variables in others(such as proxy relationships which may not apply in new application sites).Our results have implications for future DEM error prediction studies,particularly in evaluating a very wide range of potential input variables(160 candidates)drawn from topographic,multispectral,Synthetic Aperture Radar,vegetation,climate and urbanisation datasets. 展开更多
关键词 TOPOGRAPHY Explainability INTERPRETABILITY XAI SHAP ENSEMBLE
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Research progress and application prospects of die cast magnesium alloys
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作者 Mark Easton Trevor Abbott 《Journal of Magnesium and Alloys》 2025年第10期4685-4688,共4页
1.Introduction Casting accounts for over 90%of magnesium-based alloy applications with die-cast and thixomolded parts dominating.The high strength-to-weight ratio coupled with excellent fluidity,low volumetric latent ... 1.Introduction Casting accounts for over 90%of magnesium-based alloy applications with die-cast and thixomolded parts dominating.The high strength-to-weight ratio coupled with excellent fluidity,low volumetric latent heat and heat capacity,reduced cycle times,and low soldering tendencies,all make magnesium alloys excellent choices for die casting applications.Despite these advantages,in recent years,the use of magnesium in die casting applications has been declining. 展开更多
关键词 FLUIDITY high strength weight ratio heat capacity die casting die cast magnesium alloys volumetric latent heat thixomolded parts cycle times
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Acupuncture for pain management in Australia: Current status and future directions
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作者 Yanyi Wang Zhen Zheng 《Journal of Traditional Chinese Medical Sciences》 2025年第4期454-463,共10页
Chronic pain affects 3.6 million Australians and this number is projected to reach 5.23 million by 2050,costing A$73.2 billion annually.Current care relies heavily on pharmacotherapy-particularly opioids-which leads t... Chronic pain affects 3.6 million Australians and this number is projected to reach 5.23 million by 2050,costing A$73.2 billion annually.Current care relies heavily on pharmacotherapy-particularly opioids-which leads to approximately 150 hospitalizations,14 emergency visits,and three opioid-related deaths daily.National strategies now promote multimodal and non-pharmacological options.One of these options-acupuncture-offers a safe,evidence-based alternative with opioid-sparing effects for patients with acute and chronic pain.Therefore,its current application across various settings highlights its strong potential for integration into mainstream care.Here,we conducted a structured review of peer-reviewed literature,regulatory documents,workforce reports,and government publications on acupuncture to assess registration and education standards,workforce capacity,and professional and consumer acceptance of acupuncture.Australian pain management guidelines(2015-2025)that included acupuncture were systematically identified and evaluated.Acupuncture is a nationally registered profession with the protected title of“Acupuncturist.”Over 4800 practitioners currently provide care and consumer and professional attitudes are generally positive.However,public funding is minimal,with access largely dependent on out-of-pocket payments or limited private health insurance rebates.Few Australian guidelines recommend acupuncture for pain,in contrast to its more widespread endorsement in the United States and Europe.Some state health services and hospitals have piloted programs;however,their implementation remains fragmented.Global evidence,consumer acceptance,and the person-centered nature of acupuncture allow it to complement existing pain strategies and reduce opioid reliance in Australia.However,to achieve this,the profession must strengthen education in contemporary pain science,foster inter-professional collaboration,and expand research on its role in multidisciplinary care.Advocating for public funding is also critical.Embedding acupuncture within an integrated pain framework can better meet consumer needs,improve outcomes,and contribute to the long-term sustainability of the healthcare system. 展开更多
关键词 ACUPUNCTURE Pain management OPIOID REGULATORY GUIDELINES
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Revealing the limits of laser energy density: A study of the combined effects of process parameters on melt pool and microstructure in WE43 magnesium alloys
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作者 Chee Ying Tan Cuie Wen +2 位作者 Edwin Mayes Dechuang Zhang Hua Qian Ang 《Journal of Magnesium and Alloys》 2025年第3期1034-1049,共16页
Additive manufacturing(AM)has revolutionized modern manufacturing,but the application of magnesium(Mg)alloys in laser-based AM remains underexplored due to challenges such as oxidation,low boiling point,and thermal ex... Additive manufacturing(AM)has revolutionized modern manufacturing,but the application of magnesium(Mg)alloys in laser-based AM remains underexplored due to challenges such as oxidation,low boiling point,and thermal expansion,which lead to defects like porosity and cracking.This study provides a comprehensive analysis of microstructure changes in WE43 magnesium(Mg)alloy after laser surface melting(LSM),examining grain morphology,orientation,size,microsegregation,and defects under various combinations of laser power,scan speed,and spot size.Ourfindings reveal that variations in laser power and spot size exert a more significant influence on the depth and aspect ratio of the keyhole melt pool compared to laser scan speed.Critically,we demonstrate that laser energy density,while widely used as a quantitative metric to describe the combined effects of process parameters,exhibits significant limitations.Notable variations in melt pool depth,normalized width,and microstructure with laser energy density were observed,as reflected by low R²values.Additionally,we underscore the importance of assessing the temperature gradient across the width of the melt pool,which determines whether conduction or keyhole melting modes dominate.These modes exhibit distinct heatflow mechanisms and yield fundamentally different microstructural outcomes.Furthermore,we show that the microstructure and grain size in conduction mode exhibit a good correlation with the temperature gradient(G)and solidification rate(R).This research provides a framework for achieving localized microstructural control in LSM,providing insights to optimize process parameters for laser-based 3D printing of Mg alloys,and advancing the integration of Mg alloys into AM technologies. 展开更多
关键词 Laser surface melting(LSM) Magnesium alloys MICROSTRUCTURE Laser processing parameters Spot size
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Simulation Framework for Addressing Challenges in Path Planning Evaluation for an Autonomous Surface Vehicle
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作者 Chuong Nguyen Minh Tran +3 位作者 Trung-Tin Nguyen Nuwantha Fernando Liuping Wang Hung Nguyen 《哈尔滨工程大学学报(英文版)》 2025年第4期816-828,共13页
An efficient algorithm for path planning is crucial for guiding autonomous surface vehicles(ASVs)through designated waypoints.However,current evaluations of ASV path planning mainly focus on comparing total path lengt... An efficient algorithm for path planning is crucial for guiding autonomous surface vehicles(ASVs)through designated waypoints.However,current evaluations of ASV path planning mainly focus on comparing total path lengths,using temporal models to estimate travel time,idealized integration of global and local motion planners,and omission of external environmental disturbances.These rudimentary criteria cannot adequately capture real-world operations.To address these shortcomings,this study introduces a simulation framework for evaluating navigation modules designed for ASVs.The proposed framework is implemented on a prototype ASV using the Robot Operating System(ROS)and the Gazebo simulation platform.The implementation processes replicated satellite images with the extended Kalman filter technique to acquire localized location data.Cost minimization for global trajectories is achieved through the application of Dijkstra and A*algorithms,while local obstacle avoidance is managed by the dynamic window approach algorithm.The results demonstrate the distinctions and intricacies of the metrics provided by the proposed simulation framework compared with the rudimentary criteria commonly utilized in conventional path planning works. 展开更多
关键词 Autonomous surface vehicle Global path planner Local path planner Simulation Robot operating system Gazebo
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Effect of fine-grained wood biochar on the geotechnical and microstructural behaviour of expansive clay as pavement subgrade
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作者 Mohammad Saberian Jiasheng Zhu +3 位作者 Rajeev Roychand Xi Sun Jie Li Chun-Qing Li 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第10期6648-6661,共14页
Biochar,a solid carbonaceous material produced by heating biomass in oxygen-free or low-oxygen conditions(pyrolysis),has been used in various applications,including wastewater treatment,carbon sequestration,and improv... Biochar,a solid carbonaceous material produced by heating biomass in oxygen-free or low-oxygen conditions(pyrolysis),has been used in various applications,including wastewater treatment,carbon sequestration,and improving soil fertility.However,very limited research has been performed to explore its feasibility to improve the expansive clay(EC)subgrade.In this study,fine-grained wood biochar derived from wood waste was used to stabilise and enhance the mechanical performance of the EC as road subgrade.A comprehensive series of geotechnical tests,including unconfined compressive strength(UCS),California bearing ratio(CBR),repeated load triaxial(RLT),and swelling-shrinkage tests,were conducted to investigate the engineering properties of expansive clay mixed with different contents of the fine-grained biochar(FGB)(i.e.0,1%,2%,3%,and 4%by weight of dry soil).Furthermore,X-ray diffraction(XRD),X-ray fluorescence(XRF),X-ray micro-CT,and thermogravimetric analysis(TGA)analyses were performed to study the microchemical modification of the EC-FGB mixtures.The results showed that adding FGB reduced the swelling and shrinkage potential while enhancing the mechanical properties of the EC.The micro-level analysis also supported the enhancement of the geotechnical performance of the EC resulting from the incorporation of FGB.According to the test results,2%FGB was considered the optimum content,increasing UCS,CBR,and resilient modulus by 31.1%,24.1%,and 31.5%,respectively,and decreasing the swell-shrinkage index by 7%. 展开更多
关键词 Expansive clay Wood biochar Soil stabilisation Pavement subgrade
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Effect of oxygen on the microstructure,tensile properties and deformation behaviours of a biocompatible Ti40Zr25Nb25Ta10 high entropy alloy
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作者 L.Mustafi V.T.Nguyen +5 位作者 T.Song Q.Deng L.Jiang X.B.Chen D.M.Fabijanic M.Qian 《Journal of Materials Science & Technology》 2025年第11期62-73,共12页
The effect of oxygen on the microstructure,mechanical properties and deformation behaviours of as-cast biocompatible Ti40Zr25Nb25Ta10Ox(x=0.5,1.0 and 2.0 at.%)high entropy alloys(HEAs)was investi-gated.All three oxyge... The effect of oxygen on the microstructure,mechanical properties and deformation behaviours of as-cast biocompatible Ti40Zr25Nb25Ta10Ox(x=0.5,1.0 and 2.0 at.%)high entropy alloys(HEAs)was investi-gated.All three oxygen-doped HEAs solidified as a single body-centred cubic(BCC)phase grain structure with predominantly high-angle grain boundaries following the Mackenzie prediction.Increasing oxygen content significantly increased tensile strength at a rate of about 180 MPa/1.0 at.%,but decreased ten-sile ductility.However,at the addition level of 0.5 at.%O,the as-cast Ti40Zr25Nb25Ta10O0.5 HEA can achieve a yield strength(σ_(0.2))of 947±44 MPa and an elongation at break(ε_(f))of 9.5%±1.8%.These properties make this HEA comparable to medical grade Ti-6Al-4V(wt.%)alloy(ASTM Grade 23 titanium)(σ_(0.2)≥759 MPa;ε_(f)≥10%)in itsability to absorbenergy in plasticdeformation,whileoffering greater resistance to permanent shape changes.Due to the possible strong interaction between oxygen atoms and dislocations through pinning and de-pinning,all oxygen-doped HEAs exhibited discontinuous yield-ing,whereas the low oxygen base HEA underwent normal yielding.No oxygen clusters were detected through atom probe tomography(APT)analysis.The deformation mechanism depends on oxygen con-tent.The plastic deformation of the Ti40Zr25Nb25Ta10O0.5 HEA occurred through the formation of pri-mary and secondary shear bands.In contrast,planar slip bands and a limited number of primary shear bands(without secondary shear bands)were observed in the Ti40Zr25Nb25Ta10O2.0 HEA.To ensure suf-ficient ductility,the oxygen content should be limited to 0.5 at.%.Furthermore,at this oxygen content,the corrosion resistance of the Ti40Zr25Nb25Ta10O0.5 HEA in Hank’s solution is comparable to that of Ti-6Al-4V. 展开更多
关键词 High entropy alloy TITANIUM TANTALUM NIOBIUM ZIRCONIUM Deformation Corrosion resistance
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Feasibility of Micro-Hydro Power for Rural Electrification in Bangladesh:A Case Study from the Chittagong Hill Tracts
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作者 Ratan Kumar Das Abhijit Date +1 位作者 Harun Chowdhury Hamed Hassan 《Energy Engineering》 2025年第12期4815-4835,共21页
Bangladesh has achieved notable progress in expanding electricity access nationwide.Nonetheless,remote and topographically challenging regions such as the Chittagong Hill Tracts(CHT)continue to face coverage gaps due ... Bangladesh has achieved notable progress in expanding electricity access nationwide.Nonetheless,remote and topographically challenging regions such as the Chittagong Hill Tracts(CHT)continue to face coverage gaps due to grid extension difficulties.This research investigates the technical feasibility of micro-hydro power(MHP)systems as viable off-grid solutions for rural electrification in CHT.Field surveys conducted across various sites assessed available head and flow rates using GPS-based elevation measurements and portable flowmeters.Seasonal fluctuations were factored into the analysis to ensure year-round operational viability.The study involved estimating power output,selecting appropriate turbine types based on head-flow data,and proposing preliminary plant configurations.Results identify multiple locations with adequate head(2.5 to 10.4 m)and flow rates(0.10 to 0.35 m3/s),capable of generating between 1.5 and 16.5 kW,sufficient for essential rural applications.Based on site-specific head and discharge characteristics,Kaplan and Francis turbines were identified as the most suitable configurations,offering high efficiency for the medium-flow,low-to-medium head environments typical of the studied regions.Despite inherent technical potential,challenges such as seasonal variability,infrastructure complexities,and policy deficiencies remain.This investigation addresses a critical knowledge gap in local renewable energy planning.It offers a data-driven foundation for pilot projects and community-scale electrification initiatives in Bangladesh’s remote mountainous areas. 展开更多
关键词 Micro-hydro power(MHP) rural electrification Chittagong Hill Tracts(CHT) renewable energy feasibility head-flow assessment off-grid energy solutions
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Decomposition for Large-Scale Optimization Problems:An Overview
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作者 Thai Doan CHUONG Chen LIU Xinghuo YU 《Artificial Intelligence Science and Engineering》 2025年第3期157-174,共18页
Formalizing complex processes and phenomena of a real-world problem may require a large number of variables and constraints,resulting in what is termed a large-scale optimization problem.Nowadays,such large-scale opti... Formalizing complex processes and phenomena of a real-world problem may require a large number of variables and constraints,resulting in what is termed a large-scale optimization problem.Nowadays,such large-scale optimization problems are solved using computing machines,leading to an enormous computational time being required,which may delay deriving timely solutions.Decomposition methods,which partition a large-scale optimization problem into lower-dimensional subproblems,represent a key approach to addressing time-efficiency issues.There has been significant progress in both applied mathematics and emerging artificial intelligence approaches on this front.This work aims at providing an overview of the decomposition methods from both the mathematics and computer science points of view.We also remark on the state-of-the-art developments and recent applications of the decomposition methods,and discuss the future research and development perspectives. 展开更多
关键词 decomposition methods nonlinear optimization large-scale problems computational intelligence
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Adoption of digital transformation from a firm’s creation to decline:the role of China’s mass entrepreneur and innovation campaign
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作者 Umer Sahil Maqsood Qian Li R.M.Ammar Zahid 《Financial Innovation》 2025年第1期1831-1859,共29页
Following the global economy’s shift toward a digital-based system,the significance of digital transformation(DT)at the firm level has become increasingly important.Accordingly,this study aims to enhance understandin... Following the global economy’s shift toward a digital-based system,the significance of digital transformation(DT)at the firm level has become increasingly important.Accordingly,this study aims to enhance understanding of a firm’s DT by examining the varying impacts ofirm life cycle(FLC)stages on DT adoption.We consider the impact of the mass entrepreneur and innovation campaign(MEIC)on this relationship.Based on the data of China A-share non-financial companies listed on the Shanghai and Shenzhen stock exchanges from 2010 to 2020.The baseline findings reveal that firms in the growth stage are likelier to adopt DT than firms in the introduction and decline stages;however,DT adoption in the maturity stage is uncertain.MEIC encourages DT adoption during the introduction,maturity,and decline stages.Furthermore,the univariate test demonstrates a relative enhancement in DT after implementing MEIC,underscoring its role in effectively allocating resources within the firms to embrace DT.This study’s results are robust across various estimation techniques and instrumental variables.The empirical results offer insights into policy implications,highlighting the factors shaping firms’DT adoption decisions at different FLC stages and endorsing resource-based and agency theories. 展开更多
关键词 Digital transformation Digital economy Firm life cycle Mass entrepreneur Innovation campaign
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A High-Power,Flexible,and Magnetically Attachable Radiative Cooling Film
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作者 Xianbo Nian Keng-Te Lin +7 位作者 Ke Li Jifang Hei Jihong Han Yun Li Chunsheng Guo Han Lin Jinchuan Zheng Baohua Jia 《Engineering》 2025年第6期122-133,共12页
Radiative cooling is an environmentally friendly,passive cooling technology that operates without energy consumption.Current research primarily focuses on optimizing the optical properties of radiative cooling films t... Radiative cooling is an environmentally friendly,passive cooling technology that operates without energy consumption.Current research primarily focuses on optimizing the optical properties of radiative cooling films to enhance their cooling performance.In practical applications,thermal contact between the radiative cooling film and the object significantly influences the ultimate cooling performance.However,achieving optimal thermal contact has received limited attention.In this study,we propose and experimentally demonstrate a high-power,flexible,and magnetically attachable and detachable radiative cooling film.This film consists of polymer metasurface structures on a flexible magnetic layer.The monolithic design allows for convenient attachment to and detachment from steel or iron surfaces,ensuring optimal thermal contact with minimal thermal resistance and uniform temperature distribution.Our magnetic radiative cooling film exhibits superior cooling performance compared to non-magnetic alternatives.It can reduce the temperature of stainless-steel plates under sunlight by 15.2℃,which is 3.6℃ more than that achieved by non-magnetic radiative cooling films.The radiative cooling power can reach 259W·m^(-2) at a working temperature of 70℃.Unlike other commonly used attachment methods,such as thermal grease or one-off tape,our approach allows for detachment and reusability of the cooling film according to practical needs.This method offers great simplicity,flexibility,and cost-effectiveness,making it promising for broad applications,particularly on non-horizontal irregular surfaces previously considered challenging. 展开更多
关键词 Radiative cooling Thermal management MAGNETIC FLEXIBLE Cooling power
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Electrospun Membranes of Hydrophobic Polyimide and NH_(2)-UiO-66 Nanocomposite for Desalination
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作者 Seungju Kim Jue Hou +1 位作者 Namita Roy Choudhury Sandra EKentish 《Energy & Environmental Materials》 2025年第2期264-272,共9页
Hydrophobic nanofiber composite membranes comprising polyimide and metal-organic frameworks are developed for desalination via direct contact membrane distillation(DCMD).Our study demonstrates the synthesis of hydroph... Hydrophobic nanofiber composite membranes comprising polyimide and metal-organic frameworks are developed for desalination via direct contact membrane distillation(DCMD).Our study demonstrates the synthesis of hydrophobic polyimides with trifluoromethyl groups,along with superhydrophobic UiO-66(hMOF)prepared by phenylsilane modification on the metal-oxo nodes.These components are then combined to create nanofiber membranes with improved hydro ph obi city,ensuring long-term stability while preserving a high water flux.Integration of hMOF into the polymer matrix further increases membrane hydrophobic properties and provides additional pathways for vapor transport during MD.The resulting nanofiber composite membranes containing 20 wt%of hMOFs(PI-1-hMOF-20)were able to desalinate hypersaline feed solution of up to 17 wt%NaCl solution,conditions that are beyond the capability of reverse osmosis systems.These membranes demonstrated a water flux of 68.1 kg m^(-2)h^(-1) with a rejection rate of 99.98%for a simulated seawater solution of 3.5 wt%NaCl at 70℃,while maintaining consistent desalination performance for 250 h. 展开更多
关键词 DESALINATION ELECTROSPINNING membrane distillation metal organic frameworks POLYIMIDE
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MnS/MnO heterostructures with dual ion defects for high-performance aqueous magnesium ion capacitors
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作者 Minghui Liu Mudi Li +7 位作者 Siwen Zhang Yaxi Ding Ying Sun Jiazhuo Li Haixi Gu Bosi Yin Hui Li Tianyi Ma 《Journal of Magnesium and Alloys》 2025年第1期219-228,共10页
The advancement of aqueous magnesium ion energy storage devices encounters limitations due to the substantial hydration radius of magnesium ions(Mg^(2+))and their strong electrostatic interaction with the primary mate... The advancement of aqueous magnesium ion energy storage devices encounters limitations due to the substantial hydration radius of magnesium ions(Mg^(2+))and their strong electrostatic interaction with the primary material.Consequently,this study successfully developed a MnS/MnO heterostructure through a straightforward hydrothermal and annealing method,marking its initial application in aqueous magnesium ion capacitors(AMICs).The fabricated MnS/MnO heterostructure,characterized by S defects,also generates Mn defects via in-situ initiation of early electrochemical processes.This unique dual ion defects MnS/MnO heterostructure(DID-MnS/MnO)enables the transformation of MnS and MnO,initially not highly active electrochemically for Mg^(2+),into cathode materials exhibiting high electrochemical activity and superior performance.Moreover,DID-MnS/MnO enhances conductivity,improves the kinetics of surface redox reactions,and increases the diffusion rate of Mg^(2+).Furthermore,this study introduces a dual energy storage mechanism for DID-MnS/MnO,which,in conjunction with dual ion defects,offers additional active sites for Mg^(2+)insertion/deinsertion in the host material,mitigating volume expansion and structural degradation during repeated charge-discharge cycles,thereby significantly enhancing cycling reversibility.As anticipated,using a three-electrode system,the developed DID-MnS/MnO demonstrated a discharge specific capacity of 237.9 mAh/g at a current density of 0.1 A/g.Remarkably,the constructed AMIC maintained a capacity retention rate of 94.3%after 10000 cycles at a current density of 1.0 A/g,with a specific capacitance of 165.7 F/g.Hence,DID-MnS/MnO offers insightful perspectives for designing alternative clean energy sources and is expected to contribute significantly to the advancement of the clean energy sector. 展开更多
关键词 DID-MnS/MnO Dual ion defects Initial electrochemical process-induced defects Dual energy storage mechanism Aqueous magnesium ion capacitors
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