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Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

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Advances in Manufacturing 2024年第1期12卷 94-107页

作者： yan Liu qiu Tang Xin-Cheng Tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in manufacturing.For improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single Y-groove.Firstly,it summarizes the intersection forms and introduces a dual-pipe intersection model.Based on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is defined.Secondly,a novel mathematical model for plasma radius and taper compensation is established.Then,the compensation model and groove model are integrated by establishing movable frames.Thirdly,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is proposed.Through the established models and moving frames,the planned path description of cutting robot is provided in this novel scheme.The accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation

对我国优秀女子竞走运动员蒋秋艳赛前技术训练的分析

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体育成人教育学刊 2013年第2期29卷 75-78页

作者：蒋秋艳西安体育学院国少竞走队陕西西安710068

对我国优秀女子竞走运动员蒋秋艳赛前技术训练进行发析,发现:蒋秋艳步幅适中、步频较快,没有人眼可见的腾空;送髋技术动作和后蹬用力都达到了较高的水平,摆动腿摆动半径长,摆速慢;速度提升慢,造成加速不快。蒋秋艳的技术特点可为我国运... 详细信息

对我国优秀女子竞走运动员蒋秋艳赛前技术训练进行发析,发现:蒋秋艳步幅适中、步频较快,没有人眼可见的腾空;送髋技术动作和后蹬用力都达到了较高的水平,摆动腿摆动半径长,摆速慢;速度提升慢,造成加速不快。蒋秋艳的技术特点可为我国运动员技术训练带来诸多借鉴和思考。

关键词：竞走运动员田径项目技术训练

Three-scale integrated optimization model of furnace simulation,cyclic scheduling,and supply chain of ethylene plants

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Chinese Journal of Chemical Engineering 2022年第4期35卷 29-40页

作者： Kexin Bi Mingyu yan Shuyuan Zhang Tong qiu Department of Chemical Engineering Tsinghua UniversityBeijing 100084China Beijing Key Laboratory of Industrial Big Data System and Application Beijing 100084China Fushun Petrochemical Company PetroChinaFushun 113008China

In order to explore the potential of profit margin improvement,a novel three-scale integrated optimization model of furnace simulation,cyclic scheduling,and supply chain of ethylene plants is proposed and evaluated.A decoupling strategy is proposed for the solution of the three-scale model,which uses our previously proposed reactor scale model for operation optimization and then transfers the obtained results as a parameter table in the joint MILP optimization of plant-supply chain scale for cyclic scheduling.This optimization framework simplifies the fundamental mixed-integer nonlinear programming(MINLP)into several sub-models,and improves the interpretability and extendibility.In the evaluation of an industrial case,a profit increase at a percentage of 3.25%is attained in optimization compared to the practical operations.Further sensitivity analysis is carried out for strategy evolving study when price policy,supply chain,and production requirement parameters are varied.These results could provide useful suggestions for petrochemical enterprises on thermal cracking production.

关键词： Three-scale integrated optimization Cyclic scheduling Supply chain Mixed-integer linear programming Thermal cracking

Clustering for Bivariate Functional Data

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 613-629页

作者： Shi-yun CAO yan-qiu ZHOU yan-ling WAN Tao ZHANG School of Science Guangxi University of Science and TechnologyLiuzhou 545006China School of Marxism Guangxi University of Science and TechnologyLiuzhou 545006China Key Laboratory of Intelligent Information Processing and Graph Processing Guangxi University of Science and TechnologyLiuzhou 545006China

In this paper,we consider the clustering of bivariate functional data where each random surface consists of a set of curves recorded repeatedly for each subject.The k-centres surface clustering method based on marginal functional principal component analysis is proposed for the bivariate functional data,and a novel clustering criterion is presented where both the random surface and its partial derivative function in two directions are considered.In addition,we also consider two other clustering methods,k-centres surface clustering methods based on product functional principal component analysis or double functional principal component analysis.Simulation results indicate that the proposed methods have a nice performance in terms of both the correct classification rate and the adjusted rand index.The approaches are further illustrated through empirical analysis of human mortality data.

关键词： bivariate functional data -centres surface clustering functional principal component analysis partial derivative function

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中西语境下的“艺术终结”

思想战线 2009年第4期35卷 106-109页

作者：孙艳秋中国社会科学院文学研究所

"艺术终结"是黑格尔从其思想体系中演绎的重要结论,丹托立足于当代艺术迥异于传统的现状,对其进行重要的发挥,在中国学界的相关领域产生了重大而深远的影响。然而,在中国学者对这一理论的热烈讨论中透露出对之理解、阐发以及评价的多重... 详细信息

"艺术终结"是黑格尔从其思想体系中演绎的重要结论,丹托立足于当代艺术迥异于传统的现状,对其进行重要的发挥,在中国学界的相关领域产生了重大而深远的影响。然而,在中国学者对这一理论的热烈讨论中透露出对之理解、阐发以及评价的多重偏差和错位,这种尴尬很大程度上源于我们同西方异质的历史时间观,表现了中国传统循环观基础上的"艺术不死"与西方进化论前提下的"艺术终结"之间的对抗。

关键词：艺术终结黑格尔丹托当代艺术

Flexible servo riveting system control strategy based on the RBF network and self-pierce riveting process

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Advances in Manufacturing 2023年第1期11卷 39-55页

作者： yan Liu qiu Tang Xin-Cheng Tian Long Cui Center for Robotics School of Control Science and EngineeringShandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China

As more and more composite materials are used in lightweight vehicle white bodies,self-pierce riveting(SPR)technology has attracted great attention.However,the existing riveting tools still have the disadvantages of low efficiency and flexibility.To improve these disadvantages and the riveting qualification rate,this paper improves the control scheme of the existing riveting tools,and proposes a novel controller design approach of the flexible servo riveting system based on the RBF network and SPR process.Firstly,this paper briefly introduces the working principle and SPR procedure of the servo riveting tool.Then a moving component force analysis is performed,which lays the foundation for the motion control.Secondly,the riveting quality inspection rules of traditional riveting tools are used for reference to plan the force-displacement curve autonomously.To control this process,the riveting force is fed back into the closed-loop control of the riveting tool and the riveting speed is computed based on the admittance control algorithm.Then,this paper adopts the permanent magnet synchronous motor(PMSM)as the power of riveting tool,and proposes an integral sliding mode control approach based on the improved reaching law and the radial basis function(RBF)network friction compensation for the PMSM speed control.Finally,the proposed control approach is simulated by Matlab,and is applied to the servo riveting system designed by our laboratory.The simulation and riveting results show the feasibility of the designed controller.

关键词： Lightweight vehicle body connection Self-pierce riveting(SPR)process Flexible servo riveting tool Riveting force planning and control

Rare earth recovery from fluoride molten-salt electrolytic slag by sodium carbonate roasting-hydrochloric acid leaching

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Journal of Rare Earths 2023年第8期41卷 1242-1249,I0005页

作者： Hao Wu Huashan yan yanzhen Liang Sen qiu Xiaowen Zhou Dongmei Zhu Tingsheng qiu Collaborative Innovation Center for Development and Utilization of Rare Metal Resources Co-sponsored by Ministry of Education and Jiangxi Province Jiangxi University of Science and TechnologyGanzhou 341000China Jiangxi Province Key Laboratory of Mining Engineering Jiangxi University of Science and TechnologyGanzhou 341000China School of Resources and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China

Fluorinated rare earth molten-salt electrolytic slag contains a considerable amount of rare earth elements,as well as a variety of heavy metals and fluorides that cause environmental pollution.Therefore,it is of great importance to fully utilise this resource.In this study,the transformation mechanism of fluorinated rare earth molten-salt electrolytic slag roasted with sodium carbonate,and the regulation mechanism of rare earth leaching under different roasting conditions were investigated with the help of thermodynamic calculation of the reactions and kinetic analysis.The thermodynamic and differential thermal thermogravimetric(DTA-TG)analysis shows that the transformation of rare earth fluoride to rare earth oxide is promoted at elevated temperature.Furthermore,the leaching experimental results show that increasing the temperature,time,hydrochloric acid concentration,and liquid-solid ratio can effectively promote the recovery of rare earths.The optimum experimental conditions are a roasting temperature of 700℃,roasting time of 2 h,and sodium carbonate to molten salt electrolytic slag mass ratio of 0.6,followed by leaching at 80℃with a liquid-solid ratio of 10:1 by adding 3 moI/L hydrochlo ric acid with stirring for 2 h.Under these conditions,the rare earths in the molten salt electrolytic slag are biologically transformed at a lower temperature and the leaching efficiency of rare earths exceeds 98%.

关键词： Fluorinated rare earth molten-salt electrolytic slag Sodium carbonate Roasting Transformation mechanism Leaching Rare earths

Glucocorticoid reduction induced chorea in pediatric-onset systemic lupus erythematosus:A case report

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World Journal of Clinical Cases 2023年第32期11卷 7872-7875页

作者： yan-qiu Xu Miao Wang Ying Zhang Department of Rheumatology Chongqing Hospital of Traditional Chinese MedicineChongqing 400021China

BACKGROUND Pediatric-onset systemic lupus erythematosus(SLE)is typically more severe than adult-onset SLE,with a higher incidence of nervous system involvement.Chorea is a relatively rare neurological complication reported in 2.4%-7%of SLE patients.In particular,chorea induced by glucocorticoid dose reduction is even rarer.Herein,we report the case of a girl with SLE,who developed chorea during the process of glucocorticoid therapy reduction.CASE SUMMARY We describe a 14-year-old girl who was diagnosed with SLE.She was treated with methylprednisolone and rituximab,and her symptoms improved.On the second day after the methylprednisolone dose was reduced according to the treatment guidelines,the patient developed chorea.Her condition improved after adjusting her glucocorticoid regimen.CONCLUSION This case is a reminder that extra attention to chorea is required in SLE patients during glucocorticoid dose reduction.

关键词： Glucocorticoid Chorea Pediatric systemic lupus erythematosus Case report

High-resolution Projection Dataset of Agroclimatic Indicators over Central Asia

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Advances in Atmospheric Sciences 2022年第10期39卷 1734-1745页

作者： Yuan qiu Jinming FENG Zhongwei yan Jun WANG Key Laboratory of Regional Climate-Environment for Temperate East Asia(RCE-TEA) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China

To understand the potential impacts of projected climate change on the vulnerable agriculture in Central Asia(CA),six agroclimatic indicators are calculated based on the 9-km-resolution dynamical downscaled results of three different global climate models from Phase 5 of the Coupled Model Intercomparison Project(CMIP5),and their changes in the near-term future(2031-50)are assessed relative to the reference period(1986-2005).The quantile mapping(QM)method is applied to correct the model data before calculating the indicators.Results show the QM method largely reduces the biases in all the indicators.Growing season length(GSL,day),summer days(SU,day),warm spell duration index(WSDI,day),and tropical nights(TR,day)are projected to significantly increase over CA,and frost days(FD,day)are projected to decrease.However,changes in biologically effective degree days(BEDD,°C)are spatially heterogeneous.The high-resolution projection dataset of agroclimatic indicators over CA can serve as a scientific basis for assessing the future risks to local agriculture from climate change and will be beneficial in planning adaption and mitigation actions for food security in this region.

关键词： agroclimatic indicators Central Asia near-term future agriculture quantile mapping