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
The hot deformation characteristics of induction quenched Zr-Sn-Nb-Fe-Cr alloy forged rod in the temperature range of 600–900°C and strain rate range of 0.001–1 s^(-1)were studied by Gleeble3800 uniaxial hot co...The hot deformation characteristics of induction quenched Zr-Sn-Nb-Fe-Cr alloy forged rod in the temperature range of 600–900°C and strain rate range of 0.001–1 s^(-1)were studied by Gleeble3800 uniaxial hot compression experiment.The results show that the flow stress decreases with the decrease in strain rate and the increase in deformation temperature in the true stress-true strain curve of Zr-Sn-Nb-Fe-Cr alloy forged rod.Moreover,the hot deformation characteristics of the material can be described by the hyperbolic sine constitutive equation.Under the experimental conditions,the average thermal activation energy(Q)of the alloy was 412.9105 kJ/mol.The microstructure analysis of the processing map and the sample after hot compression shows that the optimum hot working parameters of the alloy are 795–900°C,0.001–0.0068 s^(-1),at the deformation temperature of 600–900°C,and the strain rate of 0.001–1 s^(-1).展开更多
Using a Gleeble 3500 thermomechanical simulation testing machine,the hot deformation characteristics of 23Cr-8Ni steel were investigated under the conditions of 1000–1250℃ and 0.001‒10 s^(−1).Furthermore,the microst...Using a Gleeble 3500 thermomechanical simulation testing machine,the hot deformation characteristics of 23Cr-8Ni steel were investigated under the conditions of 1000–1250℃ and 0.001‒10 s^(−1).Furthermore,the microstructure of the characterization region was analyzed to investigate the recrystallization behavior of 23Cr-8Ni steel.Results show that as the strain rate decreases and the deformation temperature increases,the flow stress decreases.Because the softening phenomenon occurs after the peak stress,the flow stress decreases.The stress index(n)is 4.28,and the thermal deformation activation energy(Q)is 588878 J/mol.Processing map is established,and an optimal thermal processing range of 0.001–0.1 s^(−1) and 1000–1200℃ is achieved,therefore greatly promoting the yield rate.展开更多
Bacillus cereus is a significant pathogen responsible for toxin-induced foodborne diseases,and is widely distributed in the natural environment.B.cereus biofilm formation is regulated by multifactorial interactions,de...Bacillus cereus is a significant pathogen responsible for toxin-induced foodborne diseases,and is widely distributed in the natural environment.B.cereus biofilm formation is regulated by multifactorial interactions,demonstrating dynamic adaptability to environmental cues.In this study,crystal violet staining and MTT staining methods were employed to conduct an indepth investigation into the biofilm formation and metabolic activity changes of five strains of B.cereus in different culture media and with various culture conditions.Experimental data indicated that the composition of the culture medium,the length of incubation time,and the fluctuation of temperature all had a significant impact on the biofilm formation of B.cereus,and this impact exhibited obvious differences among different strains.This result provides a solid experimental basis for deeply elucidating the internal regulatory mechanism of B.cereus biofilm formation and the change principles of metabolic activity.展开更多
Flip-chip technology is widely used in integrated circuit(IC)packaging.Molded underfill transfer molding is the most common process for these products,as the chip and solder bumps must be protected by the encapsulatin...Flip-chip technology is widely used in integrated circuit(IC)packaging.Molded underfill transfer molding is the most common process for these products,as the chip and solder bumps must be protected by the encapsulating material to ensure good reliability.Flow-front merging usually occurs during the molding process,and air is then trapped under the chip,which can form voids in the molded product.The void under the chip may cause stability and reliability problems.However,the flow process is unobservable during the transfer molding process.The engineer can only check for voids in the molded product after the process is complete.Previous studies have used fluid visualization experiments and developed computational fluid dynamics simulation tools to investigate this issue.However,a critical gap remains in establishing a comprehensive three-dimensional model that integrates two-phase flow,accurate venting settings,and fluid surface tension for molded underfill void evaluation—validated by experimental fluid visualization.This study aims to address this gap in the existing literature.In this study,a fluid visualization experiment was designed to simulate the transfer molding process,allowing for the observation of flow-front merging and void formation behaviors.For comparison,a three-dimensional mold flow analysis was also performed.It was found that the numerical simulation of the trapped air compression process under the chip was more accurate when considering the capillary force.The effect of design factors is evaluated in this paper.The results show that the most important factors for void size are fluid viscosity,the gap height under the chip,transfer time,contact angle between the fluid and the contact surfaces,and transfer pressure.Specifically,a smaller gap height beneath the chip aggravates void formation,while lower viscosity,extended transfer time,reduced contact angle,and increased transfer pressure are effective in minimizing void size.The overall results of this study will be useful for product and process design in selecting appropriate solutions for IC packaging,particularly in the development of void-free molded-underfill flip-chip packages.These findings support the optimization of industrial packaging processes in semiconductor manufacturing by guiding material selection and process parameters,ultimately enhancing package reliability and yield.展开更多
The cold-rolled quenching and partitioning(Q&P)steel with an initial microstructure of deformed ferrite and pearlite was studied.The microstructural evolution under various heating rates of 1.78,50,and 300℃/s was...The cold-rolled quenching and partitioning(Q&P)steel with an initial microstructure of deformed ferrite and pearlite was studied.The microstructural evolution under various heating rates of 1.78,50,and 300℃/s was investigated using microstructural characterization and theoretical modeling.At the same time,the characteristics of recrystallization and austenite formation kinetics were decoupled by examining recrystallized ferrite and deformed ferrite as initial conditions.The findings revealed that the austenite formation during continuous heating can be simplified into two stages:(i)the early nucleation-dominated formation stage and(ii)the later grain growth-dominated stage,resulting in the development of a modified two-stage model based on Johnson-Mehl-Avrami-Kolmogorov.Further experiments confirmed that when the austenite volume fraction exceeded approximately 5% at a heating rate of 1.78℃/s,ferrite recrystallization was suppressed.In consequence,a mixed model including recrystallization kinetics was employed to couple the austenite formation occurring in deformed ferrite and recrystallized ferrite,thereby describing the austenite formation kinetics affected by recrystallization.Precise predictions of non-isothermal austenite formation kinetics in cold-rolled Q&P steel were achieved during slow and ultrafast heating processes by integrating the suppression effect into the model for austenite formation.展开更多
For a long time,the conventional superplastic forming temperature for Ti alloys is generally too high(~900-920℃),which leads to too long production cycles,heavy surface oxidation,and property reduction.In this study,...For a long time,the conventional superplastic forming temperature for Ti alloys is generally too high(~900-920℃),which leads to too long production cycles,heavy surface oxidation,and property reduction.In this study,an ultrafine bimodal microstructure,consisting of ultrafine equiaxed microstructure(0.66μm)and 43.3%lamellar microstructure,was achieved in the Ti-6Al-4V alloy by friction stir processing(FSP).The low-temperature superplastic behavior and deformation mechanism of the FSP Ti-6Al-4V alloy were investigated at temperatures of 550-675℃and strain rates ranging from 1×10^(−4)to 3×10^(−3)s^(−1).The FSP alloy exhibited superplastic elongations of>200%at the temperature range from 550 to 650℃,and an optimal superplastic elongation of 611%was achieved at 625℃and 1×10^(−4)s^(−1).This is the first time to report the low-temperature superplasticity of the bimodal microstructure in Ti alloys.Grain boundary sliding was identified as the dominant deformation mechanism,which was effectively accommodated by the comprehensive effect of dislocation-inducedβphase precipitation and dynamic spheroidization of the lamellar structure.This study provides a novel insight into the low-temperature superplastic deformation behavior of the bimodal microstructure.展开更多
Mantle plumes and surface erosion and sediment deposition affect the modes of continental lithospheric rupturing in extensional tectonic settings,modulating the evolution of rifting margins.However,their relative cont...Mantle plumes and surface erosion and sediment deposition affect the modes of continental lithospheric rupturing in extensional tectonic settings,modulating the evolution of rifting margins.However,their relative contributions to the overall evolution of rifting margins and possible roles in the formation of microcontinent are still elusive.Here,we use coupled geodynamic and surface processes numerical modeling to assess the extent to which surface processes may determine the formation of microcontinent during lithospheric stretching in presence or absence of a mantle plume underneath.Our modeling results indicate that fast extension rates and hillslope(i.e.,diffusion)erosion promote ridge jump events and therefore the formation of microcontinents.On the contrary,efficient fluvial erosion and far-reaching sediment transport(i.e.,stream power erosion)inhibits ridge jump events and the formation of microcontinents.The ridge jump event and overall evolution in our numerical models is consistent with the shift from the Mascarene Ridge to the Carlsberg Ridge that determined the formation of the Seychelles microcontinent.We therefore speculate that hillslope erosion,rather than fluvial erosion,was predominant during the formation of the Seychelles,a possible indication of overall dry local climate conditions.展开更多
This study systematically investigates the hot deformation behavior and microstructural evolution of CoNiV medium-entropy alloy(MEA)in the temperature range of 950-1100℃ and strain rates of 0.001-1 s^(-1).The Arrheni...This study systematically investigates the hot deformation behavior and microstructural evolution of CoNiV medium-entropy alloy(MEA)in the temperature range of 950-1100℃ and strain rates of 0.001-1 s^(-1).The Arrhenius model and machine learning model were developed to forecast flow stresses at various conditions.The predictive capability of both models was assessed using the coefficients of determination(R^(2)),average absolute relative error(AARE),and root mean square error(RMSE).The findings show that the osprey optimization algorithm convolutional neural network(OOA-CNN)model outperforms the Arrhenius model,achieving a high R^(2) value of 0.99959 and lower AARE and RMSE values.The flow stress that the OOA-CNN model predicted was used to generate power dissipation maps and instability maps under different strains.Finally,combining the processing map and microstructure characterization,the ideal processing domain was identified as 1100℃ at strain rates of 0.01-0.1 s^(-1).This study provided key insights into optimizing the hot working process of CoNiV MEA.展开更多
The hot deformation behavior of GH3230 superalloy under selected deformation conditions ranging from 950 to 1150℃with strain rates ranging from 0.01 to 10 s^(–1)was studied through isothermal hot compression experim...The hot deformation behavior of GH3230 superalloy under selected deformation conditions ranging from 950 to 1150℃with strain rates ranging from 0.01 to 10 s^(–1)was studied through isothermal hot compression experiments.Based on the obtained flow stresses,a strain-compensated Arrhenius-type model was developed for the description of hot deformation behavior,and the consistency of the predicted flow stresses with the experimental values confirms the accuracy of the developed model.Furthermore,the processing maps were constructed and classified into the instability domain,low-dissipation stability domain and high-dissipation stability domain in accordance with the dynamic material model and the instability criterion.Microstructure observations indicated that the instability domain exhibits the adiabatic shear bands formation,and the low-power dissipation domain exhibits partial dynamic recrystallization(DRX),with the temperature increase/strain rate decrease being favorable for the DRX.The high-dissipation stability domain was occupied by uniformly fine equiaxed grains,and was identified as the optimal processing window,which corresponds to the deformation conditions at 1070–1150℃ with strain rates ranging from 0.01 to 0.15 s^(–1).Moreover,various DRX mechanisms are observed to occur during the hot deformation,which include the discontinuous dynamic recrystallization,characterized by nucleation at bulged boundaries,the continuous dynamic recrystallization with subgrain progressive rotation and the particle stimulated nucleation mechanism with stimulated nucleation of carbide particles.展开更多
It is of great significance for deep oil and gas exploration to understand the origin and evolution behind overpressure.Overpressure occurs in the deep Shahezi Formation of Xujiaweizi fault depression.However,due to l...It is of great significance for deep oil and gas exploration to understand the origin and evolution behind overpressure.Overpressure occurs in the deep Shahezi Formation of Xujiaweizi fault depression.However,due to limited degree of exploration,there are some problems in the study area,such as unclear understanding of the origin of overpressure and the vague investigation of overpressure evolution.To clarify the impact of overpressure on oil and gas migration and accumulation in the study area,this study focuses on the research of the origin and evolution of overpressure in the Shahezi Formation of the study area,utilizing single well logging parameters and combining methods such as microthermometry of fluid inclusions,laser Raman spectrum,and basin simulation.The results show that the overpressure of the Shahezi Formation in Xujiaweizi fault depression is primarily generated by hydrocarbon generation pressurization,and the evolution of overpressure is closely related to hydrocarbon generation.The development of overpressure can be divided into two evolutionary stages:early hydrocarbon generation pressurization and late uplift release,with slight variations in different regions.Tight glutenite gas reservoirs in the Shahezi Formation are characterized by continuous charging.The overall charging period ranges from the late Denglouku to the early Mingshui(110-67 Ma ago).There is an obvious paleo-overpressure during the gas reservoir formation period.The gas generation period of source rocks occurred approximately 125-60 Ma ago,and the main gas generation period(112-67 Ma ago)highly coincides with the period of natural gas charging.The anomalously high pressure during the accumulation period is considered the significant driving force for natural gas charging.In addition,the sustained effect of overpressure provides better conditions for the preservation of tight gas reservoirs within the source.The results of the study are of guiding significance for the in-depth exploration and development of deep tight sandstone gas in the Shahezi Formation of Xujiaweizi fault depression.展开更多
Ti750s titanium alloy,a novel high-temperature titanium alloy designed for short-term service at elevated temperatures(700–750℃),has previously lacked comprehensive understanding of its hot processing behavior.In th...Ti750s titanium alloy,a novel high-temperature titanium alloy designed for short-term service at elevated temperatures(700–750℃),has previously lacked comprehensive understanding of its hot processing behavior.In this study,the high-temperature deformation behavior and microstructural evolution of the Ti750s alloy were systematically investigated through thermal simulation compression tests conducted at temperatures ranging from 900 to 1070℃and strain rates between 0.1 and 10 s⁻1.A hot processing map was constructed using the dynamic material model to optimize the hot processing parameters.The results indicated that the optimal processing window was between 1040 and 1070℃with a strain rate of 0.1 s⁻1.Processing within the instability region resulted in localized plastic deformation,manifesting as pronounced shear bands and a highly heterogeneous strain distribution;this region should be avoided during hot deformation.Within theα+βphase safety zone characterized by low power dissipation rates between 0.32 and 0.4,the primary deformation mechanism in this region was dynamic recovery(DRV),where the lamellarαgrains underwent deformation and rotation.Conversely,in theα+βphase safety zone with high-power dissipation rates between 0.45 and 0.52,dynamic spheroidization of theαphase and dynamic recrystallization(DRX)of theβphase occurred concurrently.In theβphase safety zone with low power dissipation rates between 0.32 and 0.51,the primary deformation mechanism consisted of DRV ofβgrains,accompanied by limited DRX.However,in theβphase safety zone with high-power dissipation rates exceeding 0.56,both DRV and DRX ofβgrains took place,resulted in a significant increase in the size and number of recrystallized grains compared to those observed under low power dissipation conditions.展开更多
The microstructure development of 55VNb1 microalloyed steel after warm deformation via multi-pass biaxial compression tests was studied,and the effect of thermomechanical conditions on spheroidisation of cementite lam...The microstructure development of 55VNb1 microalloyed steel after warm deformation via multi-pass biaxial compression tests was studied,and the effect of thermomechanical conditions on spheroidisation of cementite lamellae and ferrite recrystallisation for a range of deformation temperatures(600–700℃),cooling/soaking time(water quenching,air cooling,10 and 30 min of soaking time)and interpass time(0–10 s)was analysed.During deformation,the spheroidisation of pearlite is dynamically accelerated mainly by boundary splitting mechanism together with the rapid dissolution of cementite,while ferrite softening is attributed to dynamic recovery and continuous dynamic recrystallisation.The strong microstructural evolution during cooling/soaking time indicates that deformation energy accumulated is sufficient to activate metallurgical phenomena in both phases also statically.Static spheroidisation is a diffusive process,with rate controlled by the diffusion of vacancies,as suggested by the estimated activation energy.Ferrite refinement is the result of the evolution of continuous recrystallisation and pinning effect exerted by fine,globulised and homogeneously dispersed cementite particles.Increasing temperature causes accelerated kinetics in metallurgical phenomena;therefore,cooling/soaking time becomes key parameters to achieve ultrafine grained and spheroidised microstructures.Interpass time favours spheroidisation and promotes continuous recrystallisation;however,it must be carefully controlled to find a balance between recrystallisation and Ostwald ripening to optimise microstructural development.展开更多
Laminated metal composites(LMCs)have widespread application prospects and are set to become indispensable in addressing modern engineering challenges owing to their capability of leveraging the synergy between differe...Laminated metal composites(LMCs)have widespread application prospects and are set to become indispensable in addressing modern engineering challenges owing to their capability of leveraging the synergy between different metals and tailoring performance by flexibly regulating the layered configuration.The plastic forming process,as a promising advanced manufacturing technology,has been increasingly adopted for the fabrication of LMC components due to its advantages of high material utilization rate,high production efficiency,and excellent mechanical properties of the product.This review delved into the research progress on the plastic-forming process of LMCs,including rolling,extrusion,spinning,etc.It outlined the forming principles,unique characteristics,bonding mechanisms,and the influence of key process parameters on deformation,microstructure,and property.This review focused on the heterogeneous deformation and interfacial regulation of LMCs,providing insights into the mechanisms of heterogeneous deformation,damage and fracture,and formation mechanisms of intermetallic compounds.It also delineated the experimental characterization and numerical modeling methods to elucidate the heterogeneous deformation behavior,as well as the approaches to evaluating and enhancing the performance of LMCs.Finally,the challenges and prospects of manufacturing high-performance LMCs by plastic forming process are orchestrated.展开更多
The spherical Ti particle(Ti_(p))reinforced Mg-5Zn-0.5Ca(Ti_(p)/ZX50)composite was prepared via the semisolid stirring casting process and the effects of Ti_(p)on the hot deformation and hot processing behavior of mat...The spherical Ti particle(Ti_(p))reinforced Mg-5Zn-0.5Ca(Ti_(p)/ZX50)composite was prepared via the semisolid stirring casting process and the effects of Ti_(p)on the hot deformation and hot processing behavior of matrix alloy were investigated through uniaxial hot compression testing.The results indicate that a particle deformation zone(PDZ)forms around the Ti_(p)with the deformation of the Ti_(p)/ZX50 composite,which is propitious to the dynamic recrystallization(DRX)of the matrix alloy.The range of the PDZ and the promoting effect of the Ti_(p)on DRXed nucleation are inversely related to the deformation degree of the Ti_(p).Moreover,the deformation of Ti_(p)alleviates the high stress in the matrix alloy during deformation,expanding the processing range and reducing the average deformation activation energy of the matrix alloy.Notably,the minimum processing temperature(493 K)of the Ti_(p)/ZX50 composite is significantly lower than that of hardened particle reinforced magnesium matrix composites.The hot deformation mechanism of the Ti_(p)/ZX50 composite is dislocation climb controlled by both lattice diffusion and pipe diffusion.展开更多
In the Pidgeon process involving a vertical pot,bonded slag pellets occasionally emerge at the bottom of the reduction pot,impeding smooth slag discharge.To reveal the formation mechanism of the bonded slag pellets,th...In the Pidgeon process involving a vertical pot,bonded slag pellets occasionally emerge at the bottom of the reduction pot,impeding smooth slag discharge.To reveal the formation mechanism of the bonded slag pellets,thermodynamic calculations,X-ray diffraction(XRD),X-ray fluorescence spectrometry(XRF),electron probe microanalyzer(EPMA),X-ray photoelectron spectroscopy(XPS),and differential scanning calorimetry(DSC)were employed.The bonded slag pellets mainly comprise MgO,CaSi_(2),CaO,and Ca2SiO_(4).CaSi_(2) in the bonded slag pellets is attributed to the reduction reaction between Si and CaO,yielding liquid CaSi_(2).Simultaneously,the reaction between CaSi_(2) and MgO,which will typically produce Mg vapor,is inhibited,resulting in the accumulation of CaSi_(2).Owing to the solid-liquid transition of CaSi_(2),this process culminates in the bonding of slag pellets.This study can guide the Pidgeon process optimization,enabling mitigation of the“dead pot”issue,thereby enhancing efficiency and reducing costs.展开更多
Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim ...Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.展开更多
Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing addit...Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.展开更多
Processes supported by process-aware information systems are subject to continuous and often subtle changes due to evolving operational,organizational,or regulatory factors.These changes,referred to as incremental con...Processes supported by process-aware information systems are subject to continuous and often subtle changes due to evolving operational,organizational,or regulatory factors.These changes,referred to as incremental concept drift,gradually alter the behavior or structure of processes,making their detection and localization a challenging task.Traditional process mining techniques frequently assume process stationarity and are limited in their ability to detect such drift,particularly from a control-flow perspective.The objective of this research is to develop an interpretable and robust framework capable of detecting and localizing incremental concept drift in event logs,with a specific emphasis on the structural evolution of control-flow semantics in processes.We propose DriftXMiner,a control-flow-aware hybrid framework that combines statistical,machine learning,and process model analysis techniques.The approach comprises three key components:(1)Cumulative Drift Scanner that tracks directional statistical deviations to detect early drift signals;(2)a Temporal Clustering and Drift-Aware Forest Ensemble(DAFE)to capture distributional and classification-level changes in process behavior;and(3)Petri net-based process model reconstruction,which enables the precise localization of structural drift using transition deviation metrics and replay fitness scores.Experimental validation on the BPI Challenge 2017 event log demonstrates that DriftXMiner effectively identifies and localizes gradual and incremental process drift over time.The framework achieves a detection accuracy of 92.5%,a localization precision of 90.3%,and an F1-score of 0.91,outperforming competitive baselines such as CUSUM+Histograms and ADWIN+Alpha Miner.Visual analyses further confirm that identified drift points align with transitions in control-flow models and behavioral cluster structures.DriftXMiner offers a novel and interpretable solution for incremental concept drift detection and localization in dynamic,process-aware systems.By integrating statistical signal accumulation,temporal behavior profiling,and structural process mining,the framework enables finegrained drift explanation and supports adaptive process intelligence in evolving environments.Its modular architecture supports extension to streaming data and real-time monitoring contexts.展开更多
UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important...UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important floral and fruity characteristic aroma.UV-B treatment significantly improved the aroma quality of‘Foshou’and‘Yuquan’oolong teas,increasing a-farnesene levels by 1.8-and 1.4-fold,respectively.The a-farnesene synthase(CsAFS),ELONGATED HYPOCOTYL 5(CsHY5),and myelocytomatosis protein 2(CsMYC2)exhibited a highly correlated expression pattern closely associated with a-farnesene accumulation.Single-factor treatment revealed that CsAFS expression was induced by both UV-B and mechanical wounding,with CsHY5 predominantly responding to UV-B radiation,while CsMYC2 primarily responded to tumbling-induced mechanical wounding signal.Transient suppression of CsHY5 in tea leaves reduced the expression of both CsAFS and CsMYC2 whereas CsMYC2 suppression decreased CsAFS expression.G-box motifs were identified in promoters of CsMYC2 and CsAFS,and the dual-luciferase reporter assay(LUC)and electrophoretic mobility shift assays(EMSA)demonstrated direct binding functions of CsHY5 to CsAFS and CsMYC2 promoters,as well as CsMYC2 to the CsAFS promoter.Based on sensory evaluation,odourant quantification,gene expression,and molecular functional analysis,we propose that UV-B radiation and tumbling-induced wounding signals synergistically regulate a-farnesene biosynthesis through a coordinated interaction of CsHY5 and CsMYC2 during oolong tea processing.These findings improve our understanding of flavour formation during oolong tea production and also provide novel insights into artificial light application in tea manufacturing.展开更多
文摘一、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”。
文摘The hot deformation characteristics of induction quenched Zr-Sn-Nb-Fe-Cr alloy forged rod in the temperature range of 600–900°C and strain rate range of 0.001–1 s^(-1)were studied by Gleeble3800 uniaxial hot compression experiment.The results show that the flow stress decreases with the decrease in strain rate and the increase in deformation temperature in the true stress-true strain curve of Zr-Sn-Nb-Fe-Cr alloy forged rod.Moreover,the hot deformation characteristics of the material can be described by the hyperbolic sine constitutive equation.Under the experimental conditions,the average thermal activation energy(Q)of the alloy was 412.9105 kJ/mol.The microstructure analysis of the processing map and the sample after hot compression shows that the optimum hot working parameters of the alloy are 795–900°C,0.001–0.0068 s^(-1),at the deformation temperature of 600–900°C,and the strain rate of 0.001–1 s^(-1).
文摘Using a Gleeble 3500 thermomechanical simulation testing machine,the hot deformation characteristics of 23Cr-8Ni steel were investigated under the conditions of 1000–1250℃ and 0.001‒10 s^(−1).Furthermore,the microstructure of the characterization region was analyzed to investigate the recrystallization behavior of 23Cr-8Ni steel.Results show that as the strain rate decreases and the deformation temperature increases,the flow stress decreases.Because the softening phenomenon occurs after the peak stress,the flow stress decreases.The stress index(n)is 4.28,and the thermal deformation activation energy(Q)is 588878 J/mol.Processing map is established,and an optimal thermal processing range of 0.001–0.1 s^(−1) and 1000–1200℃ is achieved,therefore greatly promoting the yield rate.
基金supported by the National Key R&D Pro-gram of China(No.2022YFD1301003)the Shandong Modern Agricultural Technology and Industry System(No.SDAIT-11-11)+4 种基金the Marine Science and Technology Innovation Project of Qingdao(No.24-1-3-hygg-25-hy)the Cooperative Scientific Research Project‘Chunhui Plan’of the Ministry of Education of PRC(No.HZKY 20220481)the Open Foundation of State Key Laboratory of Marine Food Processing&Safety Control(No.SKL202408)the Shandong Province Grant for Distin-guished Young Scholars(No.ZR2022JQ15)the Young Taishan Scholars Program of Shandong Province(No.tsqn202103094)。
文摘Bacillus cereus is a significant pathogen responsible for toxin-induced foodborne diseases,and is widely distributed in the natural environment.B.cereus biofilm formation is regulated by multifactorial interactions,demonstrating dynamic adaptability to environmental cues.In this study,crystal violet staining and MTT staining methods were employed to conduct an indepth investigation into the biofilm formation and metabolic activity changes of five strains of B.cereus in different culture media and with various culture conditions.Experimental data indicated that the composition of the culture medium,the length of incubation time,and the fluctuation of temperature all had a significant impact on the biofilm formation of B.cereus,and this impact exhibited obvious differences among different strains.This result provides a solid experimental basis for deeply elucidating the internal regulatory mechanism of B.cereus biofilm formation and the change principles of metabolic activity.
文摘Flip-chip technology is widely used in integrated circuit(IC)packaging.Molded underfill transfer molding is the most common process for these products,as the chip and solder bumps must be protected by the encapsulating material to ensure good reliability.Flow-front merging usually occurs during the molding process,and air is then trapped under the chip,which can form voids in the molded product.The void under the chip may cause stability and reliability problems.However,the flow process is unobservable during the transfer molding process.The engineer can only check for voids in the molded product after the process is complete.Previous studies have used fluid visualization experiments and developed computational fluid dynamics simulation tools to investigate this issue.However,a critical gap remains in establishing a comprehensive three-dimensional model that integrates two-phase flow,accurate venting settings,and fluid surface tension for molded underfill void evaluation—validated by experimental fluid visualization.This study aims to address this gap in the existing literature.In this study,a fluid visualization experiment was designed to simulate the transfer molding process,allowing for the observation of flow-front merging and void formation behaviors.For comparison,a three-dimensional mold flow analysis was also performed.It was found that the numerical simulation of the trapped air compression process under the chip was more accurate when considering the capillary force.The effect of design factors is evaluated in this paper.The results show that the most important factors for void size are fluid viscosity,the gap height under the chip,transfer time,contact angle between the fluid and the contact surfaces,and transfer pressure.Specifically,a smaller gap height beneath the chip aggravates void formation,while lower viscosity,extended transfer time,reduced contact angle,and increased transfer pressure are effective in minimizing void size.The overall results of this study will be useful for product and process design in selecting appropriate solutions for IC packaging,particularly in the development of void-free molded-underfill flip-chip packages.These findings support the optimization of industrial packaging processes in semiconductor manufacturing by guiding material selection and process parameters,ultimately enhancing package reliability and yield.
基金funded by the National Key R&D Program of China(No.2021YFB3702404)the National Natural Science Foundation of China(Nos.52201101 and 52274372)+1 种基金the Major Program Funding of Cisri(No.21T62450ZD)the Fundamental Research Funds for the Central Universities(Nos.FRF-TP-22-013A1 and FRF-TP-22-015A1).
文摘The cold-rolled quenching and partitioning(Q&P)steel with an initial microstructure of deformed ferrite and pearlite was studied.The microstructural evolution under various heating rates of 1.78,50,and 300℃/s was investigated using microstructural characterization and theoretical modeling.At the same time,the characteristics of recrystallization and austenite formation kinetics were decoupled by examining recrystallized ferrite and deformed ferrite as initial conditions.The findings revealed that the austenite formation during continuous heating can be simplified into two stages:(i)the early nucleation-dominated formation stage and(ii)the later grain growth-dominated stage,resulting in the development of a modified two-stage model based on Johnson-Mehl-Avrami-Kolmogorov.Further experiments confirmed that when the austenite volume fraction exceeded approximately 5% at a heating rate of 1.78℃/s,ferrite recrystallization was suppressed.In consequence,a mixed model including recrystallization kinetics was employed to couple the austenite formation occurring in deformed ferrite and recrystallized ferrite,thereby describing the austenite formation kinetics affected by recrystallization.Precise predictions of non-isothermal austenite formation kinetics in cold-rolled Q&P steel were achieved during slow and ultrafast heating processes by integrating the suppression effect into the model for austenite formation.
基金supported by the funding from the Shi Changxu Innovation Center for Advanced Materials(No.SCXKFJJ202210)the National Natural Science Foundation of China(No.52271043)+2 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2021193)the Liaoning Province Excellent Youth Foundation(No.2024JH3/10200021)the Liaoning Revitalization Talents Program(No.XLYC2403094).
文摘For a long time,the conventional superplastic forming temperature for Ti alloys is generally too high(~900-920℃),which leads to too long production cycles,heavy surface oxidation,and property reduction.In this study,an ultrafine bimodal microstructure,consisting of ultrafine equiaxed microstructure(0.66μm)and 43.3%lamellar microstructure,was achieved in the Ti-6Al-4V alloy by friction stir processing(FSP).The low-temperature superplastic behavior and deformation mechanism of the FSP Ti-6Al-4V alloy were investigated at temperatures of 550-675℃and strain rates ranging from 1×10^(−4)to 3×10^(−3)s^(−1).The FSP alloy exhibited superplastic elongations of>200%at the temperature range from 550 to 650℃,and an optimal superplastic elongation of 611%was achieved at 625℃and 1×10^(−4)s^(−1).This is the first time to report the low-temperature superplasticity of the bimodal microstructure in Ti alloys.Grain boundary sliding was identified as the dominant deformation mechanism,which was effectively accommodated by the comprehensive effect of dislocation-inducedβphase precipitation and dynamic spheroidization of the lamellar structure.This study provides a novel insight into the low-temperature superplastic deformation behavior of the bimodal microstructure.
基金financially supported by the National Science Foundation of China(No.41920104010)the China Postdoctoral Science Foundation(No.2024M762767)+3 种基金the Fundamental Research Funds for the Central University,CHD(No.300102264104)by the Postdoctoral Fellowship Program of CPSF(No.GZC20241444)supported by Fondazione Cariplo and Fondazione CDP(No.2022-1546_001)by the Italian Ministry of Education,MUR(Project Dipartimenti di Eccellenza,TECLA,Department of Earth and Environmental Sciences,University of Milano-Bicocca)。
文摘Mantle plumes and surface erosion and sediment deposition affect the modes of continental lithospheric rupturing in extensional tectonic settings,modulating the evolution of rifting margins.However,their relative contributions to the overall evolution of rifting margins and possible roles in the formation of microcontinent are still elusive.Here,we use coupled geodynamic and surface processes numerical modeling to assess the extent to which surface processes may determine the formation of microcontinent during lithospheric stretching in presence or absence of a mantle plume underneath.Our modeling results indicate that fast extension rates and hillslope(i.e.,diffusion)erosion promote ridge jump events and therefore the formation of microcontinents.On the contrary,efficient fluvial erosion and far-reaching sediment transport(i.e.,stream power erosion)inhibits ridge jump events and the formation of microcontinents.The ridge jump event and overall evolution in our numerical models is consistent with the shift from the Mascarene Ridge to the Carlsberg Ridge that determined the formation of the Seychelles microcontinent.We therefore speculate that hillslope erosion,rather than fluvial erosion,was predominant during the formation of the Seychelles,a possible indication of overall dry local climate conditions.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant No.51901078)the Central Guidance for Local Scientific and Technological Development Funding Project(Grant No.236Z1003G)+3 种基金the Science and Technology Plan Project of Tangshan City(Grant No.24130207C)the Natural Science Foundation of Hebei Province(Grant No.E2022209070)the High-level Talent Project of Hebei(Grant No.E2019100007)the Open Project Program of Key Laboratory of Ministry of Education for Modern Metallurgy Technology(Grant No.2024YJKF02).
文摘This study systematically investigates the hot deformation behavior and microstructural evolution of CoNiV medium-entropy alloy(MEA)in the temperature range of 950-1100℃ and strain rates of 0.001-1 s^(-1).The Arrhenius model and machine learning model were developed to forecast flow stresses at various conditions.The predictive capability of both models was assessed using the coefficients of determination(R^(2)),average absolute relative error(AARE),and root mean square error(RMSE).The findings show that the osprey optimization algorithm convolutional neural network(OOA-CNN)model outperforms the Arrhenius model,achieving a high R^(2) value of 0.99959 and lower AARE and RMSE values.The flow stress that the OOA-CNN model predicted was used to generate power dissipation maps and instability maps under different strains.Finally,combining the processing map and microstructure characterization,the ideal processing domain was identified as 1100℃ at strain rates of 0.01-0.1 s^(-1).This study provided key insights into optimizing the hot working process of CoNiV MEA.
基金the National Key Research and Development Program of China(No.2016YFB0700505)the National Natural Science Foundation of China(No.51571020).
文摘The hot deformation behavior of GH3230 superalloy under selected deformation conditions ranging from 950 to 1150℃with strain rates ranging from 0.01 to 10 s^(–1)was studied through isothermal hot compression experiments.Based on the obtained flow stresses,a strain-compensated Arrhenius-type model was developed for the description of hot deformation behavior,and the consistency of the predicted flow stresses with the experimental values confirms the accuracy of the developed model.Furthermore,the processing maps were constructed and classified into the instability domain,low-dissipation stability domain and high-dissipation stability domain in accordance with the dynamic material model and the instability criterion.Microstructure observations indicated that the instability domain exhibits the adiabatic shear bands formation,and the low-power dissipation domain exhibits partial dynamic recrystallization(DRX),with the temperature increase/strain rate decrease being favorable for the DRX.The high-dissipation stability domain was occupied by uniformly fine equiaxed grains,and was identified as the optimal processing window,which corresponds to the deformation conditions at 1070–1150℃ with strain rates ranging from 0.01 to 0.15 s^(–1).Moreover,various DRX mechanisms are observed to occur during the hot deformation,which include the discontinuous dynamic recrystallization,characterized by nucleation at bulged boundaries,the continuous dynamic recrystallization with subgrain progressive rotation and the particle stimulated nucleation mechanism with stimulated nucleation of carbide particles.
基金supported by Innovative Research Group Project of the National Natural Science Foundation of China(Grant Nos.42072151,42272137 and 42372144)China National Petroleum Corporation(CNPC)Forward-looking Basic and Strategic Technology Research Project(Grant No.2021DJ0205)。
文摘It is of great significance for deep oil and gas exploration to understand the origin and evolution behind overpressure.Overpressure occurs in the deep Shahezi Formation of Xujiaweizi fault depression.However,due to limited degree of exploration,there are some problems in the study area,such as unclear understanding of the origin of overpressure and the vague investigation of overpressure evolution.To clarify the impact of overpressure on oil and gas migration and accumulation in the study area,this study focuses on the research of the origin and evolution of overpressure in the Shahezi Formation of the study area,utilizing single well logging parameters and combining methods such as microthermometry of fluid inclusions,laser Raman spectrum,and basin simulation.The results show that the overpressure of the Shahezi Formation in Xujiaweizi fault depression is primarily generated by hydrocarbon generation pressurization,and the evolution of overpressure is closely related to hydrocarbon generation.The development of overpressure can be divided into two evolutionary stages:early hydrocarbon generation pressurization and late uplift release,with slight variations in different regions.Tight glutenite gas reservoirs in the Shahezi Formation are characterized by continuous charging.The overall charging period ranges from the late Denglouku to the early Mingshui(110-67 Ma ago).There is an obvious paleo-overpressure during the gas reservoir formation period.The gas generation period of source rocks occurred approximately 125-60 Ma ago,and the main gas generation period(112-67 Ma ago)highly coincides with the period of natural gas charging.The anomalously high pressure during the accumulation period is considered the significant driving force for natural gas charging.In addition,the sustained effect of overpressure provides better conditions for the preservation of tight gas reservoirs within the source.The results of the study are of guiding significance for the in-depth exploration and development of deep tight sandstone gas in the Shahezi Formation of Xujiaweizi fault depression.
基金supported by the National basic scientific research projects(JCKY2021204A004)the National Ministries and Commissions Projects(2019-112hbz)the National Natural Science Foundation of China(No.52271113).
文摘Ti750s titanium alloy,a novel high-temperature titanium alloy designed for short-term service at elevated temperatures(700–750℃),has previously lacked comprehensive understanding of its hot processing behavior.In this study,the high-temperature deformation behavior and microstructural evolution of the Ti750s alloy were systematically investigated through thermal simulation compression tests conducted at temperatures ranging from 900 to 1070℃and strain rates between 0.1 and 10 s⁻1.A hot processing map was constructed using the dynamic material model to optimize the hot processing parameters.The results indicated that the optimal processing window was between 1040 and 1070℃with a strain rate of 0.1 s⁻1.Processing within the instability region resulted in localized plastic deformation,manifesting as pronounced shear bands and a highly heterogeneous strain distribution;this region should be avoided during hot deformation.Within theα+βphase safety zone characterized by low power dissipation rates between 0.32 and 0.4,the primary deformation mechanism in this region was dynamic recovery(DRV),where the lamellarαgrains underwent deformation and rotation.Conversely,in theα+βphase safety zone with high-power dissipation rates between 0.45 and 0.52,dynamic spheroidization of theαphase and dynamic recrystallization(DRX)of theβphase occurred concurrently.In theβphase safety zone with low power dissipation rates between 0.32 and 0.51,the primary deformation mechanism consisted of DRV ofβgrains,accompanied by limited DRX.However,in theβphase safety zone with high-power dissipation rates exceeding 0.56,both DRV and DRX ofβgrains took place,resulted in a significant increase in the size and number of recrystallized grains compared to those observed under low power dissipation conditions.
基金financially supported by the European Coal and Steel Community(RFCS-2015.No.709828).
文摘The microstructure development of 55VNb1 microalloyed steel after warm deformation via multi-pass biaxial compression tests was studied,and the effect of thermomechanical conditions on spheroidisation of cementite lamellae and ferrite recrystallisation for a range of deformation temperatures(600–700℃),cooling/soaking time(water quenching,air cooling,10 and 30 min of soaking time)and interpass time(0–10 s)was analysed.During deformation,the spheroidisation of pearlite is dynamically accelerated mainly by boundary splitting mechanism together with the rapid dissolution of cementite,while ferrite softening is attributed to dynamic recovery and continuous dynamic recrystallisation.The strong microstructural evolution during cooling/soaking time indicates that deformation energy accumulated is sufficient to activate metallurgical phenomena in both phases also statically.Static spheroidisation is a diffusive process,with rate controlled by the diffusion of vacancies,as suggested by the estimated activation energy.Ferrite refinement is the result of the evolution of continuous recrystallisation and pinning effect exerted by fine,globulised and homogeneously dispersed cementite particles.Increasing temperature causes accelerated kinetics in metallurgical phenomena;therefore,cooling/soaking time becomes key parameters to achieve ultrafine grained and spheroidised microstructures.Interpass time favours spheroidisation and promotes continuous recrystallisation;however,it must be carefully controlled to find a balance between recrystallisation and Ostwald ripening to optimise microstructural development.
基金supported by the National Natural Science Foundation of China(Grant Nos.52305361,52105337,52475354,and 52090043)the BK21 Four program(SNU Materials Education/Research Division for Creative Global Leaders)+1 种基金the China Postdoctoral Science Foundation(Grant No.2023M741245),and the National Key Research and Development Program of China(Grant No.2022YFB3706903)support from the Ko-rean Ministry of Trade,Industry and Energy(MOTIE,Korea)(Grant No.20022438).
文摘Laminated metal composites(LMCs)have widespread application prospects and are set to become indispensable in addressing modern engineering challenges owing to their capability of leveraging the synergy between different metals and tailoring performance by flexibly regulating the layered configuration.The plastic forming process,as a promising advanced manufacturing technology,has been increasingly adopted for the fabrication of LMC components due to its advantages of high material utilization rate,high production efficiency,and excellent mechanical properties of the product.This review delved into the research progress on the plastic-forming process of LMCs,including rolling,extrusion,spinning,etc.It outlined the forming principles,unique characteristics,bonding mechanisms,and the influence of key process parameters on deformation,microstructure,and property.This review focused on the heterogeneous deformation and interfacial regulation of LMCs,providing insights into the mechanisms of heterogeneous deformation,damage and fracture,and formation mechanisms of intermetallic compounds.It also delineated the experimental characterization and numerical modeling methods to elucidate the heterogeneous deformation behavior,as well as the approaches to evaluating and enhancing the performance of LMCs.Finally,the challenges and prospects of manufacturing high-performance LMCs by plastic forming process are orchestrated.
基金supported by the National Natural Science Foundation of China(Nos.52271109 and 52401162)Natural Science Foundation of Shanxi(Nos.202403021211064 and 202403011212003)the Major Special Plan for Science and Technology in Shanxi Province(No.202201050201012).
文摘The spherical Ti particle(Ti_(p))reinforced Mg-5Zn-0.5Ca(Ti_(p)/ZX50)composite was prepared via the semisolid stirring casting process and the effects of Ti_(p)on the hot deformation and hot processing behavior of matrix alloy were investigated through uniaxial hot compression testing.The results indicate that a particle deformation zone(PDZ)forms around the Ti_(p)with the deformation of the Ti_(p)/ZX50 composite,which is propitious to the dynamic recrystallization(DRX)of the matrix alloy.The range of the PDZ and the promoting effect of the Ti_(p)on DRXed nucleation are inversely related to the deformation degree of the Ti_(p).Moreover,the deformation of Ti_(p)alleviates the high stress in the matrix alloy during deformation,expanding the processing range and reducing the average deformation activation energy of the matrix alloy.Notably,the minimum processing temperature(493 K)of the Ti_(p)/ZX50 composite is significantly lower than that of hardened particle reinforced magnesium matrix composites.The hot deformation mechanism of the Ti_(p)/ZX50 composite is dislocation climb controlled by both lattice diffusion and pipe diffusion.
基金China Postdoctoral Science Foundation (No. 2020M682337)。
文摘In the Pidgeon process involving a vertical pot,bonded slag pellets occasionally emerge at the bottom of the reduction pot,impeding smooth slag discharge.To reveal the formation mechanism of the bonded slag pellets,thermodynamic calculations,X-ray diffraction(XRD),X-ray fluorescence spectrometry(XRF),electron probe microanalyzer(EPMA),X-ray photoelectron spectroscopy(XPS),and differential scanning calorimetry(DSC)were employed.The bonded slag pellets mainly comprise MgO,CaSi_(2),CaO,and Ca2SiO_(4).CaSi_(2) in the bonded slag pellets is attributed to the reduction reaction between Si and CaO,yielding liquid CaSi_(2).Simultaneously,the reaction between CaSi_(2) and MgO,which will typically produce Mg vapor,is inhibited,resulting in the accumulation of CaSi_(2).Owing to the solid-liquid transition of CaSi_(2),this process culminates in the bonding of slag pellets.This study can guide the Pidgeon process optimization,enabling mitigation of the“dead pot”issue,thereby enhancing efficiency and reducing costs.
文摘Agricultural Products Processing and Storage(ISSN 3059-4510,Owner:Hunan Academy of Agricultural Sciences,China.Production and hosting:Springer Nature)is an international,peer-reviewed open access journal with the aim to offer a platform for the rapid dissemination of signifi cant,novel,and high-impact research in the fi elds of agricultural product processing science,technology,engineering,and nutrition.Additionally,supplemental issues are curated and published to facilitate in-depth discussions on special topics.
基金National Key Research and Development Program of China(2022YFB4600902)Shandong Provincial Science Foundation for Outstanding Young Scholars(ZR2024YQ020)。
文摘Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.
文摘Processes supported by process-aware information systems are subject to continuous and often subtle changes due to evolving operational,organizational,or regulatory factors.These changes,referred to as incremental concept drift,gradually alter the behavior or structure of processes,making their detection and localization a challenging task.Traditional process mining techniques frequently assume process stationarity and are limited in their ability to detect such drift,particularly from a control-flow perspective.The objective of this research is to develop an interpretable and robust framework capable of detecting and localizing incremental concept drift in event logs,with a specific emphasis on the structural evolution of control-flow semantics in processes.We propose DriftXMiner,a control-flow-aware hybrid framework that combines statistical,machine learning,and process model analysis techniques.The approach comprises three key components:(1)Cumulative Drift Scanner that tracks directional statistical deviations to detect early drift signals;(2)a Temporal Clustering and Drift-Aware Forest Ensemble(DAFE)to capture distributional and classification-level changes in process behavior;and(3)Petri net-based process model reconstruction,which enables the precise localization of structural drift using transition deviation metrics and replay fitness scores.Experimental validation on the BPI Challenge 2017 event log demonstrates that DriftXMiner effectively identifies and localizes gradual and incremental process drift over time.The framework achieves a detection accuracy of 92.5%,a localization precision of 90.3%,and an F1-score of 0.91,outperforming competitive baselines such as CUSUM+Histograms and ADWIN+Alpha Miner.Visual analyses further confirm that identified drift points align with transitions in control-flow models and behavioral cluster structures.DriftXMiner offers a novel and interpretable solution for incremental concept drift detection and localization in dynamic,process-aware systems.By integrating statistical signal accumulation,temporal behavior profiling,and structural process mining,the framework enables finegrained drift explanation and supports adaptive process intelligence in evolving environments.Its modular architecture supports extension to streaming data and real-time monitoring contexts.
基金supported by the National Natural Science Foundation of China(Grant No.32072623)the National Key Research and Development Program of China(Grant No.2021YFD1601103).
文摘UV-B application enhances the aroma quality of oolong tea;however,the underlying regulatory mechanism remains unclear.This study investigates the regulatory role of UV-B in the biosynthesis of a-farnesene,an important floral and fruity characteristic aroma.UV-B treatment significantly improved the aroma quality of‘Foshou’and‘Yuquan’oolong teas,increasing a-farnesene levels by 1.8-and 1.4-fold,respectively.The a-farnesene synthase(CsAFS),ELONGATED HYPOCOTYL 5(CsHY5),and myelocytomatosis protein 2(CsMYC2)exhibited a highly correlated expression pattern closely associated with a-farnesene accumulation.Single-factor treatment revealed that CsAFS expression was induced by both UV-B and mechanical wounding,with CsHY5 predominantly responding to UV-B radiation,while CsMYC2 primarily responded to tumbling-induced mechanical wounding signal.Transient suppression of CsHY5 in tea leaves reduced the expression of both CsAFS and CsMYC2 whereas CsMYC2 suppression decreased CsAFS expression.G-box motifs were identified in promoters of CsMYC2 and CsAFS,and the dual-luciferase reporter assay(LUC)and electrophoretic mobility shift assays(EMSA)demonstrated direct binding functions of CsHY5 to CsAFS and CsMYC2 promoters,as well as CsMYC2 to the CsAFS promoter.Based on sensory evaluation,odourant quantification,gene expression,and molecular functional analysis,we propose that UV-B radiation and tumbling-induced wounding signals synergistically regulate a-farnesene biosynthesis through a coordinated interaction of CsHY5 and CsMYC2 during oolong tea processing.These findings improve our understanding of flavour formation during oolong tea production and also provide novel insights into artificial light application in tea manufacturing.
