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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 *** 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 ***,it summarizes the intersection forms and introduces a dual-pipe intersection *** 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 ***,a novel mathematical model for plasma radius and taper compensation is ***,the compensation model and groove model are integrated by establishing movable ***,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is *** the established models and moving frames,the planned path description of cutting robot is provided in this novel *** 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

MeCP2:multifaceted roles in gene regulation and neural development

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Neuroscience Bulletin 2014年第4期30卷 601-609页

作者： tian-Lin cheng Zilong Qiu Institute of Neuroscience Shanghai Institutes for Biological SciencesChinese Academy of Sciences

Methyl-CpG-binding protein 2 （MeCP2） is a classic methylated-DNA-binding protein, dysfunctions of which lead to various neurodevelopmental disorders such as Rett syndrome and autism spectrum disorder. Initially recognized as a transcriptional repressor, MeCP2 has been studied extensively and its functions have been expanded dramatically in the past two decades. Recently, it was found to be involved in gene regulation at the post-transcriptional level. MeCP2 represses nuclear microRNA processing by interacting directly with the Drosha/DGCR8 complex. In addition to its multifaceted functions, MeCP2 is remarkably modulated by post- translational modifications such as phosphorylation, SUMOylation, and acetylation, providing more regulatory dimensions to its functions. The role of MeCP2 in the central nervous system has been studied extensively, from neurons to glia. Future investigations combining molecular, cellular, and physiological methods are necessary for defining the roles of MeCP2 in the brain and developing efficient treatments for MeCP2-related brain disorders.

关键词： MeCP2 Rett syndrome central nervous system gene expression regulation post-translationalmodification post-transcriptional regulation glia

“Redistribution” Effect of Lumpy Zone for Gas Flow in BF

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Journal of Iron and Steel Research International 2007年第6期14卷 1-7页

作者： ZHU Qing-tian cheng Shu-sen School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

The gas flow from tuyere to raceway zone by blasting involves three distributional zones, such as dripping, cohesive, and lumpy zone. The gas flow distribution in lumpy zone directly affects the gas utilization ration and smooth operation in the blast furnace. However, the furnace closeness brings about great difficulty in the study of high-temperature gas flow. The charging and blasting system affecting the gas flow and whether the top gas flow distribution could reflect its inner condition as well as the furnace state, such as hanging or scaffolding, which have become the main problems for the research on gas flow. Recently, several researches overseas studied gas flow distribution using the numerical simulation method; however, such a research was rare amongst the natives. In this study, the flow model of gas in cohesive and lumpy zone was established using the numerical simulation software and the gas flow distributions with uniform distribution of burden permeability, scaffolding of wall, and nonuniform charge level were analyzed. As a result, the effects of cohesive zone and lower parts on the gas flow are very limited and the charge level largely affects the distribution of top gas flow. Therefore, it was found that the distribution of top gas flow could hardly reflect the inner gas flow. The process is called ＂redistribution＂ effect, which means that the gas flow after passing through the raceway, dripping, and cohesive zone is distributed when it flows into the lumpy zone.

关键词： blast furnace gas flow lumpy zone numerical simulation

A comparative analysis of reticular crack on ceramic plate driven by thermal shock

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Science China(Physics,Mechanics & Astronomy) 2016年第7期59卷 46-51页

作者： XiangHong Xu ShiLong Sheng cheng tian WenJun Yuan State Key Laboratory of Nonlinear Mechanics(LNM) Institute of Mechanics Chinese Academy of Sciences

Reticular crack is generally found on the surface of ceramic material that has been subjected to a thermal-shock condition. In the present study, a quantitative effect of thermal shock and quench temperature has been studied and investigated. Experimental tests were carried out to characterize the reticular crack that has been found in the Ge Kiln, which is a famous art of the ancient Chinese culture. After comparative analysis between thermal-shock cracks and the glaze crack patterns of the Ge Kiln porcelain,it is found that this study is expected to provide a powerful tool for recurrence of the long-lost firing and cooling process of the Ge Kiln porcelain.

关键词： reticular crack thermal shock ceramics Ge Kiln porcelain

Influence of microstructure on the corrosion resistance of Fe–44Ni thin films

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International Journal of Minerals,Metallurgy and Materials 2016年第6期23卷 691-697页

作者： Lin Lu tian-cheng Liu Xiao-gang Li Corrosion and Protection Center University of Science and Technology Beijing Central Iron and Steel Research Institute

An Fe–44Ni nanocrystalline（NC） alloy thin film was prepared through electrodeposition. The relation between the microstructure and corrosion behavior of the NC film was investigated using electrochemical methods and chemical analysis approaches. The results show that the NC film is composed of a face-centered cubic phase（γ-（Fe,Ni）） and a body-centered cubic phase（α-（Fe,Ni）） when it is annealed at temperatures less than 400℃. The corrosion resistance increases with the increase in grain size, and the corresponding corrosion process is controlled by oxygen reduction. The NC films annealed at 500℃ and 600℃ do not exhibit the same pattern, although their grain sizes are considerably large. This result is attributed to the existence of an anodic phase, Fe0.947Ni0.054, in these films. Under this condition, the related corrosion process is synthetically controlled by anodic dissolution and depolarization.

关键词： iron nickel alloys nanocrystalline alloys thin films phase composition corrosion resistance annealing temperature grain size

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 ***,the existing riveting tools still have the disadvantages of low efficiency and *** 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 ***,this paper briefly introduces the working principle and SPR procedure of the servo riveting *** a moving component force analysis is performed,which lays the foundation for the motion ***,the riveting quality inspection rules of traditional riveting tools are used for reference to plan the force-displacement curve *** 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 ***,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 ***,the proposed control approach is simulated by Matlab,and is applied to the servo riveting system designed by our *** 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

Long non-coding RNA tagging and expression manipulation via CRISPR/Cas9-mediated targeted insertion

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Protein & Cell 2018年第9期9卷 820-825页

作者： tian-Lin cheng Zilong Qiu Institute of Neuroscience State Key Laboratory of NeuroscienceCAS Center for Excellence in Brain Science and IntelligenceTechnology Chinese Academy of Sciences Shanghai 200031China

Dear Editor, Long non-coding RNAs （IncRNAs）, defined as RNA transcripts longer than 200 nucleotides without the protein-coding ability （Carninci et al., 2005）, share many features with protein-coding messenger RNAs （mRNAs） such as polyadenylated 5＇ ends and multi-exonic structures （Guttman et al., 2010）. Though expression levels are less abundant, IncRNAs outnumber mRNAs with more diverse regulatory functions （Quinn and Chang, 2016）. They may serve as decoys, sponges, signals or scaffolds in regulating chromatin conformation, nuclear organization, gene expression, and protein activity in cis or trans manner （Ulitsky and Bartel, 2013; Quinn and Chang, 2016）. LncRNAs are involved in various physiological processes and their lossor gain-offunction mutations have been implicated in the pathogenesis of human diseases （Wapinski and Chang, 2011）.

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Preparation of rare-earth-modified medical stone powders and their application as conductive fillers

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International Journal of Minerals,Metallurgy and Materials 2019年第2期26卷 260-266页

作者： Li-ying Qi Su-e Hao tian-cheng Sun School of Chemistry and Chemical Engineering Harbin Institute of Technology

Traditional metal conductive fillers are expensive and prone to oxidation. Thus, the development of new conductive powders as fillers is urgently needed. A novel gaseous penetration technology was adopted to prepare La-doped medical stone powders(La-MSPs), which are inexpensive mesoporous materials, as a new kind of conductive filler material. The prepared La-MSPs attained a resistivity of 450 ?·m and were used as a filler to prepare conductive coatings with epoxy resin as the resin matrix. The influence of the La-MSPs dosage on the resistance and hardness of the coatings was also determined. The resistance and the hardness both decreased with increasing filler dosage. Finally, the optimum recipe of the conductive coatings with the most suitable fillers dosage(55 wt%) was obtained. The hardness and resistance of the coatings with 55 wt% La-MSPs were HV 4 and 5.5 × 10~7 ?, respectively.

关键词： chemical engineering conductive materials rare earths medical stone powders gaseous penetration technology

PIV EXPERIMENTAL RESEARCH OF FLOW STRUCTURE IN RECTANGULAR CHANNEL WITH TRANSVERSELY PLACED SPIRAL COIL INSERT

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Journal of Hydrodynamics 2012年第4期24卷 518-525页

作者： TANG Yu-feng tian Mao-cheng ZHANG Guan-min School of Energy Source and Power Engineering Shandong UniversityJinan 250061China

The flow field in a rectangular channel with a transversely placed spiral coil insert is investigated by Particle Image Velocimetry （PIV） measurements in both transverse and longitudinal sections. The experimental results show that multi-longitudinal vortices are induced downstream of the spiral coil and are distributed as a symmetrical vortex array along the horizontal central line of the transverse section. Along the mainstream, due to the spiral motion of the longitudinal vortices, the velocity fluctuates in a manner of the damped sinusoidal curve and the velocity component in the wall normal direction is improved in the channel. Com- pared with the flow field in a smooth channel it is found that the movement of the longitudinal vortices can cause a continuous dis- turbance near the channel walls and thus enhances the fluid velocity in the near wall region, which consequently leads to the redu- ction of the velocity gradient and a more uniform velocity distribution. With the increase of the Reynolds number, the induced longitudinal vortices gain strength and become straighter and closer to the channel walls, thus the turbulence intensity is further enha- nced in this area.

关键词： Particle Image Velocimetry (PIV) spiral coil longitudinal vortices flow disturbance