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AN IMPROVED LAND-SURFACE PROCESS MODEL AND ITS SIMULATION EXPERIMENT——PART I:LAND-SURFACE PROCESS MODEL AND ITS“OFF-LINE”TESTS AND PERFORMANCE ANALYSES 被引量:4
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作者 张晶 丁一汇 《Acta meteorologica Sinica》 SCIE 1999年第3期257-277,共21页
Based on the existing land-surface schemes and models,an improved Land-surface Process Model(LPM-ZD)has been developed.It has the following major characteristics:(1)The combination of physical equations and empirical ... Based on the existing land-surface schemes and models,an improved Land-surface Process Model(LPM-ZD)has been developed.It has the following major characteristics:(1)The combination of physical equations and empirical analytical formulae are used to construct the governing equations of soil temperature and moisture.Higher resolution of model level and physical equations are adopted for the upper soil layers,and for the lower soil layers,lower resolution of model level is adopted and empirical analytical formulae are used.(2)In land surface hydrological process,the sub-grid distribution of rainfall and its effects are taken into account. (3)A simple snow cover submodel has been used,which includes effects of snow cover on soil thermodynamics and hydrology,as well as albedo. By use of this model and three groups of point observation data,a series of“off-line”tests have been carried out.The simulation results indicate that land-surface process model has good performance and can well simulate diurnal and seasonal variation of land surface processes for many kinds of land surface covers(forest,grass,crops and desert)in different climate zone.The results simulated by the model are consistent with the observations.Later,by use of one group of observation data and the model,a series of sensitivity experiments have been done.It is shown that the model is much sensitive to some parameters,such as initial soil moisture,vegetation physical parameters as well as the proportion of the grid covered with rain.Therefore it is much important for land-surface process model to define these parameters as accurately as possible. 展开更多
关键词 land-surface process model “off-line”test sensitivity experiment
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AN IMPROVED LAND-SURFACE PROCESS MODEL AND ITS SIMULATION EXPERIMENT—PART II:COUPLING SIMULATION EXPERIMENT OF LAND-SURFACE PROCESS MODEL WITH REGIONAL CLIMATE MODEL
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作者 丁一汇 张晶 赵宗慈 《Acta meteorologica Sinica》 SCIE 2000年第1期30-45,共16页
The Land-surface Process Model(LPM-ZD)has been successfully coupled with the regional climate model RegCM2 of NCAR.Then thus-obtained coupled model(CRegCM)has been applied to simulate the climate characteristics of he... The Land-surface Process Model(LPM-ZD)has been successfully coupled with the regional climate model RegCM2 of NCAR.Then thus-obtained coupled model(CRegCM)has been applied to simulate the climate characteristics of heavy rain in middle and East China for three months from May to July 1991.and compared with model output of NCAR-RegCM2 using BATS as land- surface process scheme,abbreviated as NRegCM.The results show that CRegCM has good ability and performance.CRegCM successfully simulates the extreme precipitation event and the simulations of CRegCM for surface temperature and some physical variables related to land surface process are more reasonable than those of NRegCM. 展开更多
关键词 land-surface process model regional climate model coupled model simulation
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Transformation of Verbal Descriptions of Process Flows into Business Process Modelling and Notation Models Using Multimodal Artificial Intelligence:Application in Justice
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作者 Silvia Alayón Carlos Martín +3 位作者 Jesús Torres Manuel Bacallado Rosa Aguilar Guzmán Savirón 《Computer Modeling in Engineering & Sciences》 2026年第2期870-892,共23页
Business Process Modelling(BPM)is essential for analyzing,improving,and automating the flow of information within organizations,but traditional approaches based on manual interpretation are slow,error-prone,and requir... Business Process Modelling(BPM)is essential for analyzing,improving,and automating the flow of information within organizations,but traditional approaches based on manual interpretation are slow,error-prone,and require a high level of expertise.This article proposes an innovative alternative solution that overcomes these limitations by automatically generating comprehensive Business Process Modelling and Notation(BPMN)diagrams solely from verbal descriptions of the processes to be modeled,utilizing Large Language Models(LLMs)and multimodal Artificial Intelligence(AI).Experimental results,based on video recordings of process explanations provided by an expert from an organization(in this case,the Commercial Courts of a public justice administration),demonstrate that the proposed methodology successfully enables the automatic generation of complete and accurate BPMN diagrams,leading to significant improvements in the speed,accuracy,and accessibility of process modeling.This research makes a substantial contribution to the field of business process modeling,as its methodology is groundbreaking in its use of LLMs and multimodal AI capabilities to handle different types of source material(text and video),combining several tools to minimize the number of queries and reduce the complexity of the prompts required for the automatic generation of successful BPMN diagrams. 展开更多
关键词 process modelling verbal description BPMN LLM multimodal AI
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Processing map for oxide dispersion strengthening Cu alloys based on experimental results and machine learning modelling
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作者 Le Zong Lingxin Li +8 位作者 Lantian Zhang Xuecheng Jin Yong Zhang Wenfeng Yang Pengfei Liu Bin Gan Liujie Xu Yuanshen Qi Wenwen Sun 《International Journal of Minerals,Metallurgy and Materials》 2026年第1期292-305,共14页
Oxide dispersion strengthened(ODS)alloys are extensively used owing to high thermostability and creep strength contributed from uniformly dispersed fine oxides particles.However,the existence of these strengthening pa... Oxide dispersion strengthened(ODS)alloys are extensively used owing to high thermostability and creep strength contributed from uniformly dispersed fine oxides particles.However,the existence of these strengthening particles also deteriorates the processability and it is of great importance to establish accurate processing maps to guide the thermomechanical processes to enhance the formability.In this study,we performed particle swarm optimization-based back propagation artificial neural network model to predict the high temperature flow behavior of 0.25wt%Al2O3 particle-reinforced Cu alloys,and compared the accuracy with that of derived by Arrhenius-type constitutive model and back propagation artificial neural network model.To train these models,we obtained the raw data by fabricating ODS Cu alloys using the internal oxidation and reduction method,and conducting systematic hot compression tests between 400 and800℃with strain rates of 10^(-2)-10 S^(-1).At last,processing maps for ODS Cu alloys were proposed by combining processing parameters,mechanical behavior,microstructure characterization,and the modeling results achieved a coefficient of determination higher than>99%. 展开更多
关键词 oxide dispersion strengthened Cu alloys constitutive model machine learning hot deformation processing maps
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Foundation Models for the Process Industry:Challenges and Opportunities 被引量:4
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作者 Lei Ren Haiteng Wang +3 位作者 Yuqing Wang Keke Huang Lihui Wang Bohu Li 《Engineering》 2025年第9期53-59,共7页
With the emergence of general foundational models,such as Chat Generative Pre-trained Transformer(ChatGPT),researchers have shown considerable interest in the potential applications of foundation models in the process... With the emergence of general foundational models,such as Chat Generative Pre-trained Transformer(ChatGPT),researchers have shown considerable interest in the potential applications of foundation models in the process industry.This paper provides a comprehensive overview of the challenges and opportunities presented by the use of foundation models in the process industry,including the frameworks,core applications,and future prospects.First,this paper proposes a framework for foundation models for the process industry.Second,it summarizes the key capabilities of industrial foundation models and their practical applications.Finally,it highlights future research directions and identifies unresolved open issues related to the use of foundation models in the process industry. 展开更多
关键词 Industrial foundation model process manufacturing Artificial intelligence-generated content Embodied intelligence Intelligent manufacturing
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Review on simulation of land-surface processes on the Tibetan Plateau 被引量:4
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作者 Rui Chen MeiXue Yang +1 位作者 XueJia Wang GuoNing Wan 《Research in Cold and Arid Regions》 CSCD 2019年第2期93-115,共23页
The Tibetan Plateau(TP) has powerful dynamics and thermal effects, which makes the interaction between its land and atmosphere significantly affect climate and environment in the regional or global area. By retrospect... The Tibetan Plateau(TP) has powerful dynamics and thermal effects, which makes the interaction between its land and atmosphere significantly affect climate and environment in the regional or global area. By retrospecting the latest research progress in the simulation of land-surface processes(LSPs) over the past 20 years, this study discusses both the simulation ability of land-surface models(LSMs) and the modification of parameterization schemes from two perspectives, the models' applicability and improved parameterization schemes. Our review suggests that different LSMs can well capture the spatiotemporal variations of the physical quantities of LSPs; but none of them can be fully applied to the plateau, meaning that all need to be revised according to the characteristics specific to the TP. Avoiding the unstable iterative computation and determining the freeze-thaw critical temperature according to the thermodynamic equilibrium equation, the unreasonable freeze-thaw parameterization scheme can be improved. Due to the complex underlying surface of the TP, no parameterization scheme of roughness length can well simulate the various characteristics of the turbulent flux over the TP at different temporal scales. The uniform soil thermodynamic and hydraulic parameterization scheme is unreasonable when it is applied to the plateau, as a result of the strong soil heterogeneity. There is little research on the snow-cover process so far,and the improved scheme has no advantage over the original one due to the lack of some related physical processes. The constant interaction among subprocesses of LSPs makes the improvement of a multiparameterization scheme yield better simulation results. According to the review of existing research, adding high-quality observation stations, developing a parameterization scheme suitable for the special LSPs of the TP, and adjusting the model structures can be helpful to the simulation of LSPs on the TP. 展开更多
关键词 TIBETAN PLATEAU LAND - ATMOSPHERE interaction land-surface models model APPLICABILITY parameterized modification
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A novel constitutive model for two-stage creep aging process of 7B50 aluminum alloy and its application in springback prediction 被引量:2
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作者 Ling-zhi XU Can-yu TONG +7 位作者 Chang-zhi LIU Li-hua ZHAN Ming-hui HUANG You-liang YANG Dong-yang YAN Jian-hua YIN Hui XIA Yong-qian XU 《Transactions of Nonferrous Metals Society of China》 2025年第3期734-748,共15页
A new unified constitutive model was developed to predict the two-stage creep-aging(TSCA)behavior of Al-Zn-Mg-Cu alloys.The particular bimodal precipitation feature was analyzed and modeled by considering the primary ... A new unified constitutive model was developed to predict the two-stage creep-aging(TSCA)behavior of Al-Zn-Mg-Cu alloys.The particular bimodal precipitation feature was analyzed and modeled by considering the primary micro-variables evolution at different temperatures and their interaction.The dislocation density was incorporated into the model to capture the effect of creep deformation on precipitation.Quantitative transmission electron microscopy and experimental data obtained from a previous study were used to calibrate the model.Subsequently,the developed constitutive model was implemented in the finite element(FE)software ABAQUS via the user subroutines for TSCA process simulation and the springback prediction of an integral panel.A TSCA test was performed.The result shows that the maximum radius deviation between the formed plate and the simulation results is less than 0.4 mm,thus validating the effectiveness of the developed constitutive model and FE model. 展开更多
关键词 two-stage creep aging process bimodal precipitation constitutive modeling springback prediction Al−Zn−Mg−Cu alloy
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Design method of civil aircraft based on MBSE with improved process model
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作者 Yunong WANG An ZHANG +2 位作者 Wenhao BI Yanlong HAN Haomin LI 《Chinese Journal of Aeronautics》 2025年第12期192-213,共22页
With the raising complexity of modern civil aircraft,both academy and industry have shown strong interests on MBSE(Model-Based System Engineering).However,following the application of MBSE,the duration of the design p... With the raising complexity of modern civil aircraft,both academy and industry have shown strong interests on MBSE(Model-Based System Engineering).However,following the application of MBSE,the duration of the design phase exceeded expectations.This paper conducted a survey to the relevant participants involved in the design,revealed that a lack of proper process management is a critical issue.The current MBSE methodology does not provide clear guidelines for monitoring,controlling,and managing processes,which are crucial for both efficiency and effectiveness.To address this,the present paper introduced an improved Process Model(PM)within the MBSE framework for civil aircraft design.This improved model incorporates three new Management Blocks(MB):Progress Management Block(PMB),Review Management Block(RMB),and Configuration Management Block(CMB),developed based on the Capability Maturity Model Integration(CMMI).These additions aim to streamline the design process and better align it with engineering practices.The upgraded MBSE method with the improved PM offers a more structured approach to manage complex aircraft design projects,and a case study is conducted to validate its potential to reduce timelines and enhance overall project outcomes. 展开更多
关键词 Capability Maturity model Integration(CMMI) Civil aviation Design method MBSE process engineering process model(PM)
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Centrifuge modelling of dry granular run-out processes under deflective Coriolis condition
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作者 Bei Zhang Yandong Bi Yu Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第2期1227-1239,共13页
Coriolis effects,encompassing the dilative,compressive,and deflective manifestations,constitute pivotal considerations in the centrifugal modelling of high-speed granular run-out processes.Notably,under the deflective... Coriolis effects,encompassing the dilative,compressive,and deflective manifestations,constitute pivotal considerations in the centrifugal modelling of high-speed granular run-out processes.Notably,under the deflective Coriolis condition,the velocity component parallel to the rotational axis exerts no influence on the magnitude of Coriolis acceleration.This circumstance implies a potential mitigation of the Coriolis force's deflective impact.Regrettably,extant investigations predominantly emphasize the dilative and compressive Coriolis effects,largely neglecting the pragmatic import of the deflective Coriolis condition.In pursuit of this gap,a series of discrete element method(DEM)simulations have been conducted to scrutinize the feasibility of centrifugal modelling for dry granular run-out processes under deflective Coriolis conditions.The findings concerning the deflective Coriolis effect reveal a consistent rise in the run-out distance by 2%–16%,a modest increase in bulk flow velocity of under 4%,and a slight elevation in average flow depth by no more than 25%.These alterations display smaller dependence on the specific testing conditions due to the granular flow undergoing dual deflections in opposing directions.This underscores the significance and utility of the deflective Coriolis condition.Notably,the anticipated reduction in error in predicting the final run-out distance is substantial,potentially reaching a 150%improvement compared to predictions made under the dilative and compressive Coriolis conditions.Therefore,the deflective Coriolis condition is advised when the final run-out distance of the granular flow is the main concern.To mitigate the impact of Coriolis acceleration,a greater initial height of the granular column is recommended,with a height/width ratio exceeding 1,as the basal friction of the granular material plays a crucial role in mitigating the deflective Coriolis effect.For more transverse-uniform flow properties,the width of the granular column should be as large as possible. 展开更多
关键词 Centrifuge modelling Granular flow Run-out process Deflective coriolis condition Discrete element modelling
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Establishment of normal operating zone models by boundary points for CSTR-DC-recycle chemical processes
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作者 Poku Gyasi Jiandong Wang +1 位作者 Mengyao Wei Hao Jing 《Chinese Journal of Chemical Engineering》 2025年第9期140-157,共18页
Integrated continuous stirred-tank reactors and distillation columns with recycle(CSTR-DC-recycle)are essential components in chemical processes.This paper proposes a method to establish a normal operating zone(NOZ)mo... Integrated continuous stirred-tank reactors and distillation columns with recycle(CSTR-DC-recycle)are essential components in chemical processes.This paper proposes a method to establish a normal operating zone(NOZ)model to represent allowable variations of the CSTR-DC-recycle chemical processes.The NOZ is a geometric space containing all safe operating points of the CSTR-DC-recycle chemical processes,so that it is an effective model for process monitoring.The novelty of the proposed method is to establish the NOZ model based on boundary points.The boundary points make it possible to capture the actual geometric space irrespective of the space shape.In contrast,existing methods represent the NOZ of processes by fixed mathematical models such as ellipsoidal and convex-hull models;they are not suitable for the CSTR-DC-recycle chemical processes whose NOZs cannot be exactly defined by fixed mathematical structures.Simulated case studies based on Aspen Hysys software are given to illustrate the proposed method. 展开更多
关键词 Chemical processes Grey-box model Normal operating zone Bayesian estimation model uncertainty measurement Boundary points
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Modeling and Performance Evaluation of Streaming Data Processing System in IoT Architecture
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作者 Feng Zhu Kailin Wu Jie Ding 《Computers, Materials & Continua》 2025年第5期2573-2598,共26页
With the widespread application of Internet of Things(IoT)technology,the processing of massive realtime streaming data poses significant challenges to the computational and data-processing capabilities of systems.Alth... With the widespread application of Internet of Things(IoT)technology,the processing of massive realtime streaming data poses significant challenges to the computational and data-processing capabilities of systems.Although distributed streaming data processing frameworks such asApache Flink andApache Spark Streaming provide solutions,meeting stringent response time requirements while ensuring high throughput and resource utilization remains an urgent problem.To address this,the study proposes a formal modeling approach based on Performance Evaluation Process Algebra(PEPA),which abstracts the core components and interactions of cloud-based distributed streaming data processing systems.Additionally,a generic service flow generation algorithmis introduced,enabling the automatic extraction of service flows fromthe PEPAmodel and the computation of key performance metrics,including response time,throughput,and resource utilization.The novelty of this work lies in the integration of PEPA-based formal modeling with the service flow generation algorithm,bridging the gap between formal modeling and practical performance evaluation for IoT systems.Simulation experiments demonstrate that optimizing the execution efficiency of components can significantly improve system performance.For instance,increasing the task execution rate from 10 to 100 improves system performance by 9.53%,while further increasing it to 200 results in a 21.58%improvement.However,diminishing returns are observed when the execution rate reaches 500,with only a 0.42%gain.Similarly,increasing the number of TaskManagers from 10 to 20 improves response time by 18.49%,but the improvement slows to 6.06% when increasing from 20 to 50,highlighting the importance of co-optimizing component efficiency and resource management to achieve substantial performance gains.This study provides a systematic framework for analyzing and optimizing the performance of IoT systems for large-scale real-time streaming data processing.The proposed approach not only identifies performance bottlenecks but also offers insights into improving system efficiency under different configurations and workloads. 展开更多
关键词 System modeling performance evaluation streaming data process IoT system PEPA
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Explicit ARL Computational for a Modified EWMA Control Chart in Autocorrelated Statistical Process Control Models
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作者 Yadpirun Supharakonsakun Yupaporn Areepong Korakoch Silpakob 《Computer Modeling in Engineering & Sciences》 2025年第10期699-720,共22页
This study presents an innovative development of the exponentially weighted moving average(EWMA)control chart,explicitly adapted for the examination of time series data distinguished by seasonal autoregressive moving ... This study presents an innovative development of the exponentially weighted moving average(EWMA)control chart,explicitly adapted for the examination of time series data distinguished by seasonal autoregressive moving average behavior—SARMA(1,1)L under exponential white noise.Unlike previous works that rely on simplified models such as AR(1)or assume independence,this research derives for the first time an exact two-sided Average Run Length(ARL)formula for theModified EWMAchart under SARMA(1,1)L conditions,using a mathematically rigorous Fredholm integral approach.The derived formulas are validated against numerical integral equation(NIE)solutions,showing strong agreement and significantly reduced computational burden.Additionally,a performance comparison index(PCI)is introduced to assess the chart’s detection capability.Results demonstrate that the proposed method exhibits superior sensitivity to mean shifts in autocorrelated environments,outperforming existing approaches.The findings offer a new,efficient framework for real-time quality control in complex seasonal processes,with potential applications in environmental monitoring and intelligent manufacturing systems. 展开更多
关键词 Statistical process control average run length modified EWMA control chart autocorrelated data SARMA process computational modeling real-time monitoring
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Deep learning retrieval of 3D casting models combined with professional knowledge for process reuse
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作者 Xiao-long Pei Hua Hou +2 位作者 Li-wen Chen Zhi-qiang Duan Yu-hong Zhao 《China Foundry》 2025年第6期710-722,共13页
Accurate retrieval of casting 3D models is crucial for process reuse.Current methods primarily focus on shape similarity,neglecting process design features,which compromises reusability.In this study,a novel deep lear... Accurate retrieval of casting 3D models is crucial for process reuse.Current methods primarily focus on shape similarity,neglecting process design features,which compromises reusability.In this study,a novel deep learning retrieval method for process reuse was proposed,which integrates process design features into the retrieval of casting 3D models.This method leverages the comparative language-image pretraining(CLIP)model to extract shape features from the three views and sectional views of the casting model and combines them with process design features such as modulus,main wall thickness,symmetry,and length-to-height ratio to enhance process reusability.A database of 230 production casting models was established for model validation.Results indicate that incorporating process design features improves model accuracy by 6.09%,reaching 97.82%,and increases process similarity by 30.25%.The reusability of the process was further verified using the casting simulation software EasyCast.The results show that the process retrieved after integrating process design features produces the least shrinkage in the target model,demonstrating this method’s superior ability for process reuse.This approach does not require a large dataset for training and optimization,making it highly applicable to casting process design and related manufacturing processes. 展开更多
关键词 CASTING 3D model retrieval process reuse deep learning
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Hot Deformation Behavior of CoNiV Medium-Entropy Alloy:Constitutive Model,Convolutional Neural Network,Hot Processing Map,and Microstructure Evolution
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作者 Biao Zhang Yuntian Du +6 位作者 Huishuang Jia Yuanyi Zhou Liguang Wang Minghe Zhang Yunli Feng Weimin Gao Ning Xu 《Acta Metallurgica Sinica(English Letters)》 2025年第8期1275-1292,共18页
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
关键词 Hot deformation Arrhenius model Machine learning CoNiV MEA Hot processing map
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Textile Manufacturing Carbon Emission Analysis Method Based on Holographic Process Model
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作者 GAO Jun LI Jie +1 位作者 BAO Jinsong ZHANG Dan 《Journal of Donghua University(English Edition)》 2025年第6期580-593,共14页
The textile industry,while creating material wealth,also exerts a significant impact on the environment.Particularly in the textile manufacturing phase,which is the most energy-intensive phase throughout the product l... The textile industry,while creating material wealth,also exerts a significant impact on the environment.Particularly in the textile manufacturing phase,which is the most energy-intensive phase throughout the product lifecycle,the problem of high energy usage is increasingly notable.Nevertheless,current analyses of carbon emissions in textile manufacturing emphasize the dynamic temporal characteristics while failing to adequately consider critical information such as material flows and energy consumption.A carbon emission analysis method based on a holographic process model(HPM)is proposed to address these issues.First,the system boundary in the textile manufacturing is defined,and the characteristics of carbon emissions are analyzed.Next,an HPM based on the object-centric Petri net(OCPN)is constructed,and simulation experiments are conducted on three different scenarios in the textile manufacturing.Subsequently,the constructed HPM is utilized to achieve a multi-perspective analysis of carbon emissions.Finally,the feasibility of the method is verified by using the production data of pure cotton products from a certain textile manufacturing enterprise.The results indicate that this method can analyze the impact of various factors on the carbon emissions of pure cotton product production,and by applying targeted optimization strategies,carbon emissions have been reduced by nearly 20%.This contributes to propelling the textile manufacturing industry toward sustainable development. 展开更多
关键词 textile manufacturing carbon emission analysis holographic process model sustainable development
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Optimized Lagged Multiple Linear Regression Model for MJO Prediction:Considering the Surface and Subsurface Oceanic Processes over the Maritime Continent
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作者 LU Kecheng LI Yiran +1 位作者 HU Haibo WANG Ziyi 《Journal of Ocean University of China》 2025年第4期840-850,共11页
The Madden-Julian Oscillation(MJO)is a key atmospheric component connecting global weather and climate.It func-tions as a primary source for subseasonal forecasts.Previous studies have highlighted the vital impact of ... The Madden-Julian Oscillation(MJO)is a key atmospheric component connecting global weather and climate.It func-tions as a primary source for subseasonal forecasts.Previous studies have highlighted the vital impact of oceanic processes on MJO propagation.However,few existing MJO prediction approaches adequately consider these factors.This study determines the critical region for the oceanic processes affecting MJO propagation by utilizing 22-year Climate Forecast System Reanalysis data.By intro-ducing surface and subsurface oceanic temperature within this critical region into a lagged multiple linear regression model,the MJO forecasting skill is considerably optimized.This optimization leads to a 12 h enhancement in the forecasting skill of the first principal component and efficiently decreases prediction errors for the total predictions.Further analysis suggests that,during the years in which MJO events propagate across the Maritime Continent over a more southerly path,the optimized statistical forecasting model obtains better improvements in MJO prediction. 展开更多
关键词 Madden-Julian Oscillation statistical forecasting Maritime Continent oceanic processes lagged multiple linear re-gression model
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Multiscale anisotropic fracturing model of hard rock based on the competitive process of crack propagation
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作者 Chen Fan Xiating Feng +2 位作者 Jun Zhao Chengxiang Yang Mengfei Jiang 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第8期4952-4965,共14页
During the excavation of deep engineering,high in situ stress is one prominent feature that often causes instability in the vicinity of underground openings.The propagation and coalescence of cracks in the surrounding... During the excavation of deep engineering,high in situ stress is one prominent feature that often causes instability in the vicinity of underground openings.The propagation and coalescence of cracks in the surrounding rock are characterized by anisotropy under a true triaxial stress state and play a crucial role in the development of stress-induced engineering disasters.Thus,a three-dimensional anisotropic fracturing model of hard rock is proposed to interpret fracturing activities and evaluate the mechanical property deterioration under complex stress conditions.This anisotropic fracturing model is derived from the evolution of microcracks and attributes the inelastic deformation of hard rock to crack propagation and coalescence.Through analyzing the competitive process of crack propagation in different orientations,the stress-induced anisotropic fracturing characteristics and the post-peak brittle-ductile transition could be revealed.Finally,the accuracy and effectiveness of this model are validated.Results show that this proposed anisotropic fracturing model can elucidate the primary characteristics observed in triaxial compression tests,which offers a fresh perspective on comprehending the failure process of hard rock. 展开更多
关键词 Anisotropic fracturing model True triaxial stress Competitive process Microcrack propagation and coalescence Post-peak brittle-ductile transition
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Multi-Phase Degradation Modeling Based on Uncertain Random Process for Remaining Useful Life Prediction Under Triple Uncertainties
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作者 Xuerui Cao Kaixiang Peng Ruihua Jiao 《IEEE/CAA Journal of Automatica Sinica》 2025年第6期1129-1143,共15页
Due to abrupt changes in the intrinsic degradation mechanism or shock from external environmental pressure,degradations of some equipment are characterized by multi-phase and jumps.Meanwhile,equipment is subject to in... Due to abrupt changes in the intrinsic degradation mechanism or shock from external environmental pressure,degradations of some equipment are characterized by multi-phase and jumps.Meanwhile,equipment is subject to inherent fluctuations,limited data and imperfect measurements resulting in aleatory,epistemic and measurement uncertainties of the degradation process.This paper proposes a degradation model and remaining useful life(RUL)prediction method under triple uncertainties for a category of complex equipment with multi-phase degradation and jumps.First,a multi-phase degradation model with random jumps and measurement errors is constructed based on uncertain random processes.Afterward,the analytic expression of RUL prediction considering the heterogeneity is derived by modeling the uncertainty of degradation states at change points under the concept of first hitting time.A stochastic uncertain approach is utilized for the proposed multi-phase degradation model to identify model parameters based on historical data.Furthermore,the implied degradation features are adaptively updated in online stage using similarity-based weighted stochastic uncertain maximum likelihood estimation and Kalman filtering.Finally,the effectiveness of the method is verified by simulation example and practical case. 展开更多
关键词 Measurement errors multi-phase degradation model random jumps remaining useful life(RUL)prediction uncertain random process
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A Knowledge Push Method of Complex Product Assembly Process Design Based on Distillation Model-Based Dynamically Enhanced Graph and Bayesian Network
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作者 Fengque Pei Yaojie Lin +2 位作者 Jianhua Liu Cunbo Zhuang Sikuan Zhai 《Chinese Journal of Mechanical Engineering》 2025年第6期117-134,共18页
Under the paradigm of Industry 5.0,intelligent manufacturing transcends mere efficiency enhancement by emphasizing human-machine collaboration,where human expertise plays a central role in assembly processes.Despite a... Under the paradigm of Industry 5.0,intelligent manufacturing transcends mere efficiency enhancement by emphasizing human-machine collaboration,where human expertise plays a central role in assembly processes.Despite advancements in intelligent and digital technologies,assembly process design still heavily relies on manual knowledge reuse,and inefficiencies and inconsistent quality in process documentation are caused.To address the aforementioned issues,this paper proposes a knowledge push method of complex product assembly process design based on distillation model-based dynamically enhanced graph and Bayesian network.First,an initial knowledge graph is constructed using a BERT-BiLSTM-CRF model trained with integrated human expertise and a fine-tuned large language model.Then,a confidence-based dynamic weighted fusion strategy is employed to achieve dynamic incremental construction of the knowledge graph with low resource consumption.Subsequently,a Bayesian network model is constructed based on the relationships between assembly components,assembly features,and operations.Bayesian network reasoning is used to push assembly process knowledge under different design requirements.Finally,the feasibility of the Bayesian network construction method and the effectiveness of Bayesian network reasoning are verified through a specific example,significantly improving the utilization of assembly process knowledge and the efficiency of assembly process design. 展开更多
关键词 Complex product assembly process Large language model Dynamic incremental construction of knowledge graph Bayesian network Knowledge push
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Study on Numerical Simulation of the Impact of the Land-Surface Process in a Meiyu Front Rainstorm
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作者 LI Peng 《Meteorological and Environmental Research》 CAS 2011年第10期78-83,94,共7页
[Objective]The research aimed to carry out numerical simulation on impact of land-surface process in a Meiyu front rainstorm.[Method]Based on the meso-scale atmospheric non-hydrostatic model GRAPES-Meso which coupled ... [Objective]The research aimed to carry out numerical simulation on impact of land-surface process in a Meiyu front rainstorm.[Method]Based on the meso-scale atmospheric non-hydrostatic model GRAPES-Meso which coupled with NOAH land-surface module,a Meiyu front rainstorm in Jianghuai basin during 6-8 July,2005 was simulated.Via sensitivity tests with and without land-surface process,the impact of land-surface process on Meiyu front rainstorm was studied.[Result]GRAPES-Meso which coupled with NOAH land-surface process could simulate daily variation characteristics of Meiyu front precipitation and atmospheric low-level southwest jet.The land-surface process could improve the simulations of precipitation initiation,intensity and distribution.The improvement of precipitation initiation simulation was especially obvious,which solved spin-up problem of model to some extent.When the land-atmosphere interaction wasn’t considered,the precipitation initiation of model was very slow.The intensity evolution of simulated precipitation was different from actual situation.Moreover,it couldn’t simulate daily variation characteristics of precipitation and southwest jet.[Conclusion]The land-surface process had important impact on Meiyu process in Jianghuai basin. 展开更多
关键词 GRAPES-Meso RAINSTORM NOAH land-surface process Numerical simulation China
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