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SGT-Net: A Transformer-Based Stratified Graph Convolutional Network for 3D Point Cloud Semantic Segmentation

Computers, Materials & Continua 2024年第6期79卷 4471-4489页

作者： suyi liu Jianning Chi Chengdong Wu Fang Xu Xiaosheng Yu Faculty of Robot Science and Engineering Northeastern UniversityShenyang110167China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang110169China SIASUN Robot&Automation Co. Ltd.Shenyang110169China

In recent years,semantic segmentation on 3D point cloud data has attracted much attention.Unlike 2D images where pixels distribute regularly in the image domain,3D point clouds in non-Euclidean space are irregular and inherently sparse.Therefore,it is very difficult to extract long-range contexts and effectively aggregate local features for semantic segmentation in 3D point cloud space.Most current methods either focus on local feature aggregation or long-range context dependency,but fail to directly establish a global-local feature extractor to complete the point cloud semantic segmentation tasks.In this paper,we propose a Transformer-based stratified graph convolutional network(SGT-Net),which enlarges the effective receptive field and builds direct long-range dependency.Specifically,we first propose a novel dense-sparse sampling strategy that provides dense local vertices and sparse long-distance vertices for subsequent graph convolutional network(GCN).Secondly,we propose a multi-key self-attention mechanism based on the Transformer to further weight augmentation for crucial neighboring relationships and enlarge the effective receptive field.In addition,to further improve the efficiency of the network,we propose a similarity measurement module to determine whether the neighborhood near the center point is effective.We demonstrate the validity and superiority of our method on the S3DIS and ShapeNet datasets.Through ablation experiments and segmentation visualization,we verify that the SGT model can improve the performance of the point cloud semantic segmentation.

关键词： 3D point cloud semantic segmentation long-range contexts global-local feature graph convolutional network dense-sparse sampling strategy

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Synthesis,structure and properties of three novel transition-metal-containing tantalum-phosphate clusters

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Chinese Chemical Letters 2022年第10期33卷 4675-4678页

作者： Xue Li Hui Zhao Yuyan Li Yuanyuan Yang Mingyang Zhang suyi liu Pengtao Ma Jingping Wang Jingyang Niu Henan Key Laboratory of Polyxometalate Chemistry College of Chemistry and Chemical EngineeringHenan UniversityKaifeng 475004China

Peroxide ligation of aqueous metal-oxo clusters provides rich speciation and structural diversity.Here,three novel transition-metal derivatives of polyoxometalate anions,[Ni_(2)(H_(2)O)_(10){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(6-)(1a),[Zn(H_(2)O)_(4){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(8-)(2a)and[Cd(H_(2)O)_(4){P_(4)Ta_(6)(O_(2))_(6)O_(24)}]^(8-)(3a),have been successfully synthesized by adopting a one-pot reaction strategy.All of these hexatantalates are built from a new-type phosphorus-incorporated hexatantalates.We investigated the solution behaviors,and the peak assignments of the MS spectra indicated some degree of stability of them in water.Furthermore,the proton-conducting ability of compound 1a was also explored and it has shown well conductivity at high relative humidities,with conductivity achieved 1.22×10^(-3) S/cm(85℃,90%RH).

关键词： Polyoxotantalates Transition-metal Synthesize Structure Proton-conduction

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萨南油田无泄漏示范区优化运行管理模式研究

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石油石化节能与计量 2024年第6期14卷 82-86页

作者：刘苏毅大庆油田有限责任公司第二采油厂

为进一步拓展管道完整性管理工作内容,探索完整性管理新模式,降低管道失效率,在萨南油田建设大庆油田首个无泄漏示范区工程。为切实改善该区域内腐蚀失效态势,依托无泄漏示范区建设工程,从“管理制度、组织结构、示范引领、科技赋能”... 详细信息

为进一步拓展管道完整性管理工作内容,探索完整性管理新模式,降低管道失效率,在萨南油田建设大庆油田首个无泄漏示范区工程。为切实改善该区域内腐蚀失效态势,依托无泄漏示范区建设工程,从“管理制度、组织结构、示范引领、科技赋能”四个方面实施优化运行管理模式,实现了管道零失效的新突破,保障了示范区内管道等基础设施的高质量运行,减少因油田管道失效泄漏对环境的危害以及安全隐患和经济损失,实现了绿色高效发展。

关键词：无泄漏示范区管道失效优化运行管理模式

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Design and Implementation of Digital Control of Photovoltaic Power Inverter

Design and Implementation of Digital Control of Photovoltaic...

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2011 2ND International Conference on Innovative Computing and Communication and 2011 Asia-Pacific Conference on Information Technology and Ocean Engineering(CICC-ITOE 2011)

作者： Huanqi Tao suyi liu College of Electronics and Information Engineering Wuhan Textile University

Inverter grid-connected PV system as a network interface with the main equipment, the control technology has become a research hotspot. Based on the theoretical analysis, a brief introduction of photovoltaic grid-connected inverter system structure and working principle, a linear control model of the inverter, the focus of the working conditions of its control grid design and Digital Realization process. Proposed to achieve zero steady state error conditions for sinusoidal current control, the use of band-pass filter type BPFM（Band-Pass Filter Mode） controller and inverter output current control, achieve high performance inverter Grid. Digital signal processor with TMS320LF2407A（DSP） as the controller design and simulation of the system parameters to achieve the small photovoltaic inverter good control.

关键词： Photovoltaic.Power inverter.Zero steady state.Band-pass filter.Digital Signal Processor.

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基于响应曲面法的三元地聚合物注浆材料耐久性能研究

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硅酸盐通报 2024年第3期43卷 938-947页

作者：陈士军龚木联刘溯逸花思旭金修伟王昊东华理工大学土木与建筑工程学院南昌330013

为满足复杂地层条件下隧道同步注浆材料耐久性能要求,以粉煤灰、矿渣、偏高岭土等材料制备三元地聚合物注浆材料,并对其耐久性能进行研究。在探究原料物化性质的基础上,采用响应曲面法中Box-Behnken设计耐久性试验,对试验结果进行显著... 详细信息

为满足复杂地层条件下隧道同步注浆材料耐久性能要求,以粉煤灰、矿渣、偏高岭土等材料制备三元地聚合物注浆材料,并对其耐久性能进行研究。在探究原料物化性质的基础上,采用响应曲面法中Box-Behnken设计耐久性试验,对试验结果进行显著性分析、方差分析以及三维响应曲面分析,结合XRD、SEM和EDS分析地聚合物结石体的微观形貌和水化产物。结果表明:粉煤灰、偏高岭土和矿渣能形成性能互补效应,三者相互作用对注浆材料的侵蚀系数影响显著,可有效增强其抗硫酸盐离子侵蚀能力;预测确定系数R_(pred)^(2)为0.9328,试验相对误差为0.71%,模型精确度高,通过优化获得最佳配合比参数为水泥45.183%(质量分数,下同)、粉煤灰20%、偏高岭土20%、矿渣14.817%;地聚合物注浆材料水化产物主要为方解石、C-A-S-H和N-A-S-H凝胶等物质,这些物质紧密交接,交错生长,形成致密的三维空间网络结构支撑体系,有效增强了材料的耐久性能。研究结果可为三元地聚合物注浆材料耐久性能的后续研究及生产应用提供参考。

关键词：地聚合物粉煤灰矿渣偏高岭土耐久性能

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Second harmonic generation of laser beams in transverse mode locking states

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Advanced Photonics 2022年第2期4卷 68-77页

作者： Zilong Zhang Yuan Gao Xiangjia Li Xin Wang suyi Zhao Qiang liu Changming Zhao Beijing Institute of Technology School of Optics and PhotonicsBeijingChina Ministry of Education Key Laboratory of Photoelectronic Imaging Technology and SystemBeijingChina Ministry of Industry and Information Technology Key Laboratory of Photonics Information TechnologyBeijingChina Arizona State University School for Engineering of MatterTransport and EnergyDepartment of Aerospace and Mechanical EngineeringTempeArizonaUnited States Ministry of Education Key Laboratory of Photonic Control Technology(Tsinghua University)BeijingChina Tsinghua University Department of Precision InstrumentState Key Laboratory of Precision Measurement Technology and InstrumentsBeijingChina

Nonlinear frequency conversion of structured beams has been of great interest recently.We present an intracavity second harmonic generation(SHG)of laser beams in transverse mode locking(TML)states with a specially designed sandwich such as a microchip laser.The intracavity nonlinear frequency conversion process of a laser beam in a TML state to its second harmonic is theoretically and experimentally investigated,considering different relative phase and weight parameters between the basic modes in the TML beam.Comparison between the far-field SHG beam patterns of fundamental frequency transverse modes in coherently locked and incoherently superposed states demonstrates that the SHG of TML beams can carry more information.Various rarely observed far-field SHG beam patterns are obtained,and they are consistent with the theoretical analysis and numerical simulations.With the obtained SHG beams,the characteristics of the structured fundamental frequency beams can also be conversely investigated or predicted.This work may have important applications in optical 3D printing,optical trapping of particles,and free-space optical communication areas.

关键词： transverse mode locking optical vortex lattice structured beams second harmonic generation

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Ethyl esters enhancement of Jinchuan pear wine studied by coculturing Saccharomyces bayanus with Torulaspora delbrueckii and their community and interaction characteristics

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Food Bioscience 2022年第2期46卷 734-740页

作者： Jian liu Miao liu Pian Ye Cheng He Yingjie liu suyi Zhang Jun Huang Jun Zhou Rongqing Zhou Liang Cai College of Biomass Science and Engineering Sichuan UniversityChengdu610065SichuanChina National Engineering Laboratory of Clean Technology for Leather Manufacture Sichuan UniversityChengdu610065SichuanChina National Engineering Research Centre of Solid-state Brewing Luzhou646000SichuanChina Luzhoulaojiao Company Limited Luzhou646000SichuanChina

To enhance the fruity flavour of pear wine by coculturing Saccharomyces yeasts with non-Saccharomyces,the coculture patterns were optimised based on the effect of different strains on the physicochemical properties and metabolites,and the interaction relationship in the coculture fermentation was also studied.These results showed that total volatiles of S.bayanus were higher than those of S.cerevisiae,especially esters,acids and phenols.The contents of total volatiles and esters were enhanced by sequential inoculation.The effect of coculturing S.bayanus Y4 with T.delbrueckii Y7 or Pichia sp.was better than that of coculturing with them with S.cerevisiae Y1,enhancing the contents of phenylethanol,acetate and ethyl esters.Furthermore,the esters(mainly ethyl esters)content was increased by 53.30%,and the acids content was decreased by 32.82%when S.bayanus Y4 was cocultured with T.delbrueckii Y7 by sequential inoculation compared with S.bayanus Y4 single inoculation.Their coculture increased theα-diversity of the fungal community and changed the correlation network between the microbiota.Redundancy analysis showed that Torulaspora was closely correlated to ethyl hexanoate,ethyl decanoate and ethyl 9-decenoate,while Saccharomyces was associated with hexanoic acid and octanoic acid.PICRUSt2 prediction revealed that Torulaspora may utilize the fatty acids produced by Saccharomyces to synthesize fatty acid ethyl esters.

关键词： Pear wine Saccharomyces yeasts Metabolites Coculture Community

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Physical quantity synergy in the field of turbulent heat transfer and its analysis for heat transfer enhancement

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Chinese Science Bulletin 2010年第23期55卷 2589-2597页

作者： liu Wei liu ZhiChun HUANG suyi School of Energy and Power Engineering Huazhong University of Science and Technology Wuhan 430074 China

Based on the principle of physical quantity synergy in the field of laminar heat transfer,and according to the models of zero equation and k-ε two equations for the turbulent flow,the synergy equations for both energy and momentum conservation in the turbulent heat transfer are established.The synergy regulation among heat flux,mass flow and fluid driving force,and the mechanism of heat transfer enhancement it reflects are revealed.The synergy principle of physical quantity in the thermal flow field is extended from laminar flow to turbulent flow.The principle is verified to be universal by the calculation of heat transfer enhancement in a tube with an insert of helical twisted tape.Thus,corresponding to the synergy relation among physical quantities in the turbulent flow field,the performance of convective heat transfer and flow resistance for the tubes with different heat transfer components and surface can be compared through theoretical and computational analysis,which thereby provides a guidance for designing heat transfer units and heat exchangers.

关键词：场协同原理传热强化湍流换热物理量动量守恒方程强化传热机理方程模型协同作用

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Design of Robot Welding Seam Tracking System with Structured Light Vision

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Chinese Journal of Mechanical Engineering 2010年第4期23卷 436-442页

作者： liu suyi WANG Guorong ZHANG Hua JIA Jianping Provincial Key Lab of Robot and Weld Automation Nanchang University Nanchang 330031 China School of Mechanical andAutomotive Engineering South China University of Technology Guangzhou 510640 China

Robot welding is an important developing direction of welding automation and intelligentization, and automatic seam tracking technology is one of principal research domains. Nowadays, seam tracking system with structured light vision becomes a hot research. Structured light vision seam tracking products abroad are generally very expensive and can only be applied on special occasions. In China, the research of structured light vision seam tracking system is still just on the stage of experiments. A robot real-time seam tracking system with line structured light vision is designed. The hardware system is set up, a filtering method for line structure seam image is improved, and compared with common filtering, it has better effect and characteristic of real time. Two methods, fast template matching and fast Hough transform, to recognize the image coordinates of seam center are improved. Two new image recognition methods, structure element matching and comer detecting, are proposed. The comparison of seam image recognition shows that fast template matching and comer detecting are more precise and stable than the other two methods, and comer detecting is the best in real time. A simultaneous calibration for camera parameters and robot hand-eye is also proposed, and calculation shows that the calibration is effective and feasible. The robot seam tracking tests for linear and folded lap-joint are performed, which are based on the above four image recognition methods, and the results indicate that four image recognition methods are all applicable to real-time seam tracking, and the whole system sufficed for the requirements of real-time seam tracking. Automatic seam tracking with line structured light vision is feasible and has good versatility.

关键词： laser vision robot seam tracking image recognition

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Flow mechanism and heat transfer enhancement in longitudinal-flow tube bundle of shell-and-tube heat exchanger

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Science China(Technological Sciences) 2009年第10期52卷 2952-2959页

作者： Wei liu ZhiChun liu YingShuang Wang suyi Huang School of Energy and Power Engineering Huazhong University of Science and Technology Wuhan 430074 China

The flow disturbance and heat transfer mechanism in the tube bundle of rod baffle shell-and-tube heat exchanger were analyzed, on the basis of which and combined with the concept of heat transfer enhancement in the core flow, a new type of shell-and-tube heat exchanger with combination of rod and van type spoiler was designed. Corresponding mathematical and physical models on the shell side about the new type heat exchanger were established, and fluid flow and heat transfer characteristics were numerically analyzed. The simulation results showed that heat transfer coefficient of the new type of heat exchanger approximated to that of rod baffle heat exchanger, but flow pressure drop was much less than the latter, indicating that comprehensive performance of the former is superior to that of the latter. Compared with rod baffle heat exchanger, heat transfer coefficient of the heat exchanger under investigation is higher under same pressure drop, especially under the high Reynolds numbers.

关键词： shell-and-tube heat exchanger tube bundle rod baffle vane-type spoiler core flow heat transfer enhancement

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