检索结果-南通市图书馆

Self-assembled aerogel sheet electrodes of thermocells for low-grade heat harvest

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1672-1679页

作者： Ziwei Mo Shouhao Wei Daibin xie Kaihua Zhu Hongxiong Li Xin Lu Lirong Liang Chunyu Du Zhuoxin Liu guangming Chen College of Materials Science and Engineering Shenzhen UniversityShenzhen 518055China State Key Laboratory of Polymer Materials Engineering Sichuan UniversityChengdu 610065China

Efficiently harvesting low-grade heat is crucial for sustainable energy management. Thermocells(TECs), inducing heat-toelectricity conversion via the thermogalvanic effect, have thus drawn tremendous attention in recent years. This study introduces a self-assembly approach for fabricating aerogel sheet electrodes(ASEs) tailored for TECs. The crafted ASEs retain a remarkable porous architecture with approximately 95% porosity, even with their slimmed-down thickness. Results reveal that the electrode composition has minimal influence on the thermopower of TECs. Notably, the porous ASE with tunned composition demonstrates an optimal effective surface area for the thermogalvanic effect, resulting in enhanced output current density. This balances the desirable traits of electrode compactness with abundant redox active sites, positioning it favorably against conventional bulky electrode designs. The TECs utilizing the optimized ASE achieve a peak output power of 22.10 μW cm^(-2)under a temperature difference of 30 K. Furthermore, a tubular TEC device is readily assembled and specially designed for harvesting heat energy from hot fluids. These findings underscore the potential of composite electrodes in the realm of low-grade heat harvest, paving the way for broader applications in sustainable energy solutions.

关键词： thermocells low-grade heat harvest energy conversion composite electrodes

Microstructure and toughness of thick-gauge pipeline steel joint via double-sided friction stir welding combined with preheating

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2023年第4期30卷 724-733页

作者： guangming xie Ruihai Duan Yuqian Wang Zong’an Luo Guodong Wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

Fusion welding easily causes microstructural coarsening in the heat-affected zone(HAZ) of a thick-gauge pipeline steel joint. This is most significant in the inter-critically coarse-grained HAZ(ICCGHAZ), which considerably deteriorates the toughness of the joint. In the present work, 11-mm thick pipeline steel was joined by preheating and double-sided friction stir welding(FSW). A comparative study on the microstructure and toughness in the ICCGHAZs for FSW and gas metal arc welding(GMAW) was performed. The toughness in the ICCGHAZ for FSW was improved significantly than that in the ICCGHAZ for GMAW. Generally, the nugget zone(NZ) has a coarse microstructure in the FSW steel joint formed at the highest peak temperature. However, in the current study, the microstructure in the one-pass NZ was remarkably refined owing to the static recrystallization of ferrite. An excellent toughness was achieved in the NZ of the pipeline steel joint that employed FSW.

关键词： pipeline steel thick-gauge plate friction stir welding microstructure toughness

Fish Lateral Line Inspired Flow Sensors and Flow-aided Control: A Review

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2021年第2期18卷 264-291页

作者： Yufan Zhai Xingwen Zheng guangming xie State Key Laboratory for Turbulence and Complex Systems Intelligent Biomimetic Design LabCollege of EngineeringPeking UniversityBeijing 100871China Institute of Ocean Research Peking UniversityBeijing 100871China Peng Cheng Laboratory Shenzhen 518055China

Any phenomenon in nature is potential to be an inspiration for us to propose new ideas.Lateral line is a typical example which has attracted more interest in recent years.With the aid of lateral line,fish is capable of acquiring fluid information around,which is of great significance for them to survive,communicate and hunt underwater.In this paper,we briefly introduce the morphology and mechanism of the lateral line first.Then we focus on the development of artificial lateral line which typically consists of an array of sensors and can be installed on underwater robots.A series of sensors inspired by the lateral line with different sensing principles have been summarized.And then the applications of artificial lateral line systems in hydrodynamic environment sensing and vortices detection,dipole oscillation source detection,and autonomous control of underwater robots have been reviewed.In addition,the existing problems and future foci in this field have been further discussed in detail.The current works and future foci have demonstrated that artificial lateral line has great potentials of applications and contributes to the development of underwater robots.

关键词： lateral line artificial lateral line bio-inspired flow sensor flow-aided control underwater robot

Event-triggered Tracking Consensus with Packet Losses and Time-varying Delays

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2016年第2期3卷 165-173页

作者： Mei Yu Chuan Yan Dongmei xie guangming xie the Department of Control and Computer Engineering North China Electric Power University the Department of Mathematics School of Sciences Tianjin University the Department of Engineering Peking University

This paper mainly investigates the event-triggered tracking control for leader-follower multi-agent systems with the problems of packet losses and time-varying delays when both the first-order and the second-order neighbors' information are used. Event-triggered control laws are adopted to reduce the frequency of individual actuation updating under the sampleddata framework for discrete-time agent dynamics. The communication graph is undirected and the loss of data across each communication link occurs at certain probability, which is governed by a Bernoulli process. One numerical example is given to demonstrate the effectiveness of the proposed methods.It is found that the tracking consensus is sped up by using the second-order neighbors' information when packet losses and time-varying delays occur.

关键词： Consensus leader-follower multi-agent systems second-order neighbors’ information packet losses eventtriggered time-varying delays

Modelling of thrust generated by oscillation caudal fin of underwater bionic robot

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2016年第5期37卷 601-610页

作者： Xinyan YIN Lichao JIA Chen WANG guangming xie Key State Laboratory for Turbulence and Complex Systems College of Engineering Peking University

A simplified model of the thrust force is proposed based on a caudal fin oscillation of an underwater bionic robot. The caudal fin oscillation is generalized by cen- tral pattern generators （CPGs）. In this model, the drag coefficient and lift coefficient are the two critical parameters which are obtained by the digital particle image velocimetry （DPIV） and the force transducer experiment. Numerical simulation and physical experi- ments have been performed to verify this dynamic model.

关键词： caudal fin oscillation thrust force underwater bionic robot digital particleimage velocimetry （DPIV） central pattern generator （CPG）

Toward Coordination Control of Multiple Fish-Like Robots:Real-Time Vision-Based Pose Estimation and Tracking via Deep Neural Networks

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2021年第12期8卷 1964-1976页

作者： Tianhao Zhang Jiuhong Xiao Liang Li Chen Wang guangming xie State Key Laboratory of Turbulence and Complex Systems Intelligent Biomimetic Design LaboratoryCollege of EngineeringPeking UniversityBeijing 100871China National Engineering Research Center of Software Engineering Peking UniversityBeijing 100871 Institute of Ocean Research Peking UniversityBeijing100871 Peng Cheng Laboratory Shenzhen 518055China

Controlling multiple multi-joint fish-like robots has long captivated the attention of engineers and biologists,for which a fundamental but challenging topic is to robustly track the postures of the individuals in real time.This requires detecting multiple robots,estimating multi-joint postures,and tracking identities,as well as processing fast in real time.To the best of our knowledge,this challenge has not been tackled in the previous studies.In this paper,to precisely track the planar postures of multiple swimming multi-joint fish-like robots in real time,we propose a novel deep neural network-based method,named TAB-IOL.Its TAB part fuses the top-down and bottom-up approaches for vision-based pose estimation,while the IOL part with long short-term memory considers the motion constraints among joints for precise pose tracking.The satisfying performance of our TAB-IOL is verified by testing on a group of freely swimming fish-like robots in various scenarios with strong disturbances and by a deed comparison of accuracy,speed,and robustness with most state-of-the-art algorithms.Further,based on the precise pose estimation and tracking realized by our TAB-IOL,several formation control experiments are conducted for the group of fish-like robots.The results clearly demonstrate that our TAB-IOL lays a solid foundation for the coordination control of multiple fish-like robots in a real working environment.We believe our proposed method will facilitate the growth and development of related fields.

关键词： Deep neural networks formation control multiple fish-like robots pose estimation pose tracking

Interfacial Microstructure and Properties of a Vacuum Hot Roll-bonded Titanium-Stainless Steel Clad Plate with a Niobium Interlayer

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 754-760页

作者： Zongan LUO Guanglei WANG guangming xie Lipeng WANG Kun ZHAO State Key Laboratory of Rolling and Automation Northeastern University Shougang Jingtang Iron & Steel Co. Ltd.

Vacuum hot roll bonding （VHRB） was used to bond pure titanium （Ti） plate to a 304 stainless steel （SS） plate with a niobium （Nb） interlayer, with the aim of producing a high-quality Ti-SS clad plate. The roll-bonding process was performed at different temperatures in the range of 850-1000℃, followed by characterization of microstructure and mechanical properties. The study demonstrates that the interfaces are free from cracks and discontinuities, and interdiffusion between the stainless steel and the titanium is effectively prevented by inserting a layer of pure Nb foil. No intermetallic reaction layer occurred at the Nb-Ti interface at any of the investigated temperatures. An intermetallic FeNb phase was formed at the Nb-SS interface when bonding was performed at 950 ℃ and above. The presence of the FeNb layer was confirmed by x-ray diffraction. The maximum shear strength of -396 MPa was obtained when bonding is carried out at 900 ℃. However, the formation of the FeNb layer at roll bonding temperature greater than 900 ℃ led to decrease in shear strength. Ductile fracture occurred through the Ti-Nb interface for roll-bonded temperatures of up to 900 ℃. On the other hand, at temperature of 950℃ and above, failure occurred through the Nb-SS interface, with brittle fracture characteristics.

关键词： Vacuum hot roll bonding （VHRB） Clad plate Interlayer Interface Shearstrength Intermetallic compound

热处理对电弧增材制造低碳马氏体不锈钢构件均匀性的影响

在线全文

学校读者我要写书评

暂无评论

钢铁 2024年第6期59卷 72-82页

作者：田宛平金志起谢广明东北大学轧制技术及连轧自动化国家重点实验室

采用冷金属过渡（cold metal transfer, CMT）电弧熔丝技术制备了低碳马氏体不锈钢薄壁构件。为研究热处理工艺对构件微观组织和力学性能均匀性的影响，采用OM、SEM、EBSD、XRD等技术进行了组织表征，并通过拉伸和硬度试验测试构件力学... 详细信息

采用冷金属过渡（cold metal transfer, CMT）电弧熔丝技术制备了低碳马氏体不锈钢薄壁构件。为研究热处理工艺对构件微观组织和力学性能均匀性的影响，采用OM、SEM、EBSD、XRD等技术进行了组织表征，并通过拉伸和硬度试验测试构件力学性能。结果表明，沉积态构件底部为等轴晶，组织为板条马氏体+回火马氏体；顶部为粗大柱状晶，沿构件高度生长，组织为单一板条马氏体。自构件底部至顶部，沉积态构件硬度由314HV上升至361HV；抗拉强度先上升后下降，伸长率由23.5%下降至12.0%。拉伸断裂形式均为韧性断裂，但相比于底部拉伸断口，顶部的韧窝明显更大更浅，表明塑性急剧下降。晶粒形貌、相组成等变化是由随沉积高度增加，热积累增加、冷速下降以及自回火程度降低所导致。因此，沉积态构件的组织和性能存在不均匀性。另外，由构件中部的织构特征和横、纵向力学性能可知，沉积态构件的组织和性能存在各向异性。经热处理后，构件各处的自回火程度差异被消除，相组成全部变为回火马氏体与弥散分布的逆转变奥氏体，因此获得了均匀分布的硬度及拉伸性能。另外，由于热处理过程中发生了奥氏体重结晶，构件的各向异性也被消除。揭示了热处理对电弧增材低碳马氏体构件微观组织与力学性能变化的影响机制，为工程应用提供了指导。

关键词：低碳马氏体不锈钢电弧增材热处理不均匀性各向异性

超大尺寸高性能异材质多复合平板硫化机加热板的研究与开发

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

锻压技术 2024年第5期49卷 102-108页

作者：邬早勤谢广明王磊骆宗安唐山文丰特钢有限公司河北唐山063200 东北大学轧制技术及连轧自动化国家重点实验室辽宁沈阳110819 河北工业大学材料科学与工程学院天津300131

采用真空焊接复合制备了45钢+Q355B钢的AB型坯料,并通过调整该AB型复合坯料加热时在加热炉的上、下烧嘴的加热负荷,对AB型钢板进行了不对称复合坯轧制。通过二次真空焊接复合制备了45钢+Q355B钢+Q355B钢+45钢的ABBA型坯料,并对焊缝进行... 详细信息

采用真空焊接复合制备了45钢+Q355B钢的AB型坯料,并通过调整该AB型复合坯料加热时在加热炉的上、下烧嘴的加热负荷,对AB型钢板进行了不对称复合坯轧制。通过二次真空焊接复合制备了45钢+Q355B钢+Q355B钢+45钢的ABBA型坯料,并对焊缝进行焊后高温回火处理,得到了ABBA型轧制复合板。结果表明:ABBA型复合板的界面为良好的冶金结合,平均硬度值为(180±10)HBW,组织成分均匀,各位置的硬度无明显差异。基材45钢中主要由片状珠光体和块状铁素体组成,复材Q355B钢主要由大量铁素体和少量珠光体组成。复合板厚度方向的断面收缩率平均值为62.67%,性能优异。此外,还实际生产了170 mm×3420 mm×10620 mm的ABBA型复合板,单重超过48000 kg。

关键词： 45钢 Q355B钢复合板轧制高温塑性