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基于区域生长优化的水利工程设施点云单体化研究

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水电能源科学 2024年第7期42卷 216-220页

作者：杨夏森张晓春项兴华邵广俊胡伟飞武汉大学水资源工程与调度全国重点实验室湖北武汉430072 国网浙江省电力有限公司紧水滩水力发电厂浙江丽水323000

水利工程中输变电设施安全监测是保证水电站安全运行的重要环节,其中基于点云的变形监测需要准确分割出各种输变电设施。为此,通过对三维点云进行降维处理,获取水利工程设施的二维点云图像,基于区域生长算法和点云单体化算法实现分割工... 详细信息

水利工程中输变电设施安全监测是保证水电站安全运行的重要环节,其中基于点云的变形监测需要准确分割出各种输变电设施。为此,通过对三维点云进行降维处理,获取水利工程设施的二维点云图像,基于区域生长算法和点云单体化算法实现分割工作。同时在区域生长算法的基础上提出了一种旋转角度优化算法,通过旋转三维点云数据,得到易于分割的最优角度点云图像,提高了区域生长算法的精度和速度。为验证旋转角度算法的精度,设计了仿真试验分割立柱点云,试验结果精确率达98%以上,表明旋转角度算法可应用于结构点云单体化领域。实际水利工程应用结果表明,所提方法可有效解决普通像素图像过分割的问题,能准确分割水利工程不同区域及设施。

关键词：点云单体化旋转角度算法区域生长算法水利工程设施分割

Numerical Study on Aerodynamic Performance of Floating Dual-Rotor Wind Turbines in Heave and Surge Motions

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China Ocean Engineering 2023年第6期37卷 1011-1021页

作者： WU Xiao-di LU Wen-hao WANG Kai hu wei-fei FANG Jian-hao ZHA Ruo-si School of Ocean Engineering and Technology Sun Yat-sen University&Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519000China State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou 310058China School of Mechanical Engineering Zhejiang UniversityHangzhou 310058China

Compared with the traditional wind turbine of a single rotor,dual-rotor wind turbines(DRWTs)have higher wind energy capture efficiency and a more complex ***,the aerodynamic performance of the DRWT installed on the floating platform will be greatly affected by the motion caused by wind and wave *** this paper,5 MW and 750 kW single rotor wind turbines(SRWTs)are combined into a 5 MW-5 MW DRWT and a 5 MW-750 kW DRWT,and their power output and wake field characteristics in different motions are *** flow field is obtained by solving the Reynolds-averaged Navier–Stokes equation(RANS).The overset grid technique is employed to achieve the large-amplitude multiple-degree-of-freedom motion of the *** overall performance of the 5 MW single rotor wind turbine is determined by a numerical *** the DRWTs,numerical results show that the surge motion and heave motion both have a negative effect on the power output of the *** surge motion is a critical factor that causes the power output of the DRWT to periodically change with *** average power output of the DRWT influenced by motion is lower than that of a DRWT with a fixed *** surge motion significantly disturbs the wake of the DRWT due to the mutual interference between the upstream and downstream *** the influence of heave motion,low-velocity regions downstream of the blade tip are *** study indicates that attenuating the surge and heave motion of offshore DRWT is very significant for improving its efficiency and should be taken into consideration during the design procedure.

关键词： DRWT surge motion heave motion wake field power output

Comparative analysis of thermodynamic and mechanical responses between underground hydrogen storage and compressed air energy storage in lined rock caverns

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International Journal of Mining Science and Technology 2024年第4期34卷 531-543页

作者： Bowen hu Liyuan Yu Xianzhen Mi fei Xu Shuchen Li wei Li Chao wei Tao Zhang State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Large Structure Health Monitoring and Control Shijiazhuang Tiedao UniversityShijiazhuang 050043China School of Mechanics and Civil Engineering China University of Mining and TechnologyXuzhou 221116China

Underground hydrogen storage(UHS)and compressed air energy storage(CAES)are two viable largescale energy storage technologies for mitigating the intermittency of wind and solar ***,it is meaningful to compare the properties of hydrogen and air with typical thermodynamic storage *** study employs a multi-physical coupling model to compare the operations of CAES and UHS,integrating gas thermodynamics within caverns,thermal conduction,and mechanical deformation around rock *** thermodynamic responses are validated using additional simulations and the field test *** and pressure variations of air and hydrogen within rock caverns exhibit similarities under both adiabatic and diabatic simulation *** reaches higher temperature and pressure following gas charging stage compared to air,and the ideal gas assumption may lead to overestimation of gas temperature and *** steel lining of CAES,the sealing layer(fibre-reinforced plastic FRP)in UHS is prone to deformation but can effectively mitigates stress in the sealing *** CAES,the first principal stress on the surface of the sealing layer and concrete lining is tensile stress,whereas UHS exhibits compressive stress in the same *** present research can provide references for the selection of energy storage methods.

关键词： Underground hydrogen storage Compressed air energy storage Mechanical response Thermodynamic response Lined rock caverns

A wide-linear-range and low-hysteresis resistive strain sensor made of double-threaded conductive yarn for human movement detection

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Journal of Materials Science & Technology 2024年第5期172卷 202-212页

作者： fei huang Jiyong hu Xiong Yan Shanghai Frontier Science Research Center for Modern Textiles Donghua UniversityShanghai 201620China

Yarn-based flexible strain sensors with advantages in wearability and integrability have attracted wide ***,it is still a big challenge to achieve yarn-based strain sensors with a wide linear strain range,low hysteresis,and durability synchronously that can be used for full range detection of human body ***,a new structure,double-threaded conductive yarn with rhythmic strain distribu-tion,is reported to markedly widen the linear strain range of microcrack-based stretchable strain sensors.A new method of winding and thermally adhering hot-melt filaments on the surface of the elastic fiber is used to achieve double-threaded yarn(DTY)with rhythmic strain *** proposed strategy,the integration of heterogeneous materials,is reported to significantly reduce the mechanical hysteresis of composite *** strain distribution of the DTY during stretching causes multi-level micro-cracks in different regions of the carbon nanotube(CNT)conductive layer deposited on the surface of the ***,the sensing performance of DTY-based strain sensor can be adjusted by designing the structural *** final prepared flexible strain sensor has the advantages of a wide linear strain range(100%),great sensitivity(GF=12.43),low hysteresis,rapid response(158 ms),high repeatability(>2000 cycles at 50%strain),and hydrophobicity,*** sensor can monitor human motion repeatedly and stably well,and shows great advantages in flexible wearable devices.

关键词： Double-threaded yarn Strain redistribution Hysteresis human motion monitoring

Enhancing adhesive bond strength of CFRP/titanium joints through NaOH anodising and resin pre-coating treatments with optimised anodising conditions

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Chinese Journal of Aeronautics 2024年第2期37卷 511-523页

作者： Yunsen hu Jingheng ZHANG Lin WANG fei CHENG Xiaozhi hu School of Materials and Chemistry Southwest University of Science and TechnologyMianyang 621000China School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Engineering Research Center of Biomass Materials Ministry of EducationSouthwest University of Science and TechnologyMianyang 621010China Department of Mechanical Engineering University of Western AustraliaPerthWA 6009Australia

Adhesively Bonded Carbon Fibre Reinforced Plastic(CFRP)and titanium alloy have been extensively used as a hybrid structure in modern aircrafts due to their excellent combination of mechanical properties and chemical *** study utilised NaOH anodising method to create micro-rough titanium surfaces for enhancing adhesive bonding between titanium alloy and CFRP laminates.A special and simple technique named Resin Pre-Coating(RPC)was also employed to improve the surface wetting of anodised titanium and grinded CFRP *** influences of anodising temperature and duration on the surface morphology,wettability and adhesive bond strength were *** single lap shear test results showed that the bond strength of specimens anodised at 20℃for 15 min improved by 135.9%and 95.4%,respectively,in comparison with that of acid pickled and grinded specimens(without RPC treatment).Although increasing the anodising temperature and duration produced rougher titanium surfaces,the adhesively bonded joints were not strong enough due to relatively friable titanium oxide layers.

关键词： Carbon Fibre Reinforced Polymer(CFRP) Titanium alloy Anodising Resin pre-coating Adhesive joints

Dielectric and energy storage properties of PbO–SrO–Nb_(2)O_(5)–Na_(2)O–Si thin films by annealing

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Rare Metals 2024年第1期43卷 351-355页

作者： fei-hu Tan Qing-Meng Zhang Feng wei Hong-Bin Zhao Xiao Zhang Jun Du State Key Laboratory of Advanced Materials for Smart Sensing General Research Institute for Nonferrous MetalsBeijing 100088China Advanced Electronic Materials Institute General Research Institute for Nonferrous MetalsBeijing 100088China

Dielectric and energy storage properties of PbOSrO-Na_(2)O-Nb_(2)O_(5)-SiO_(2)(PSNNS) thin films with annealing temperature from 700 to 850 ℃ were investigated by measuring their capacitance-electric filed curve and hysteresis *** results show that the highest dielectric constant and energy density are 81.2 and 17.0 J·cm^(-3),respectively,which is obtained in the sample with annealing temperature of 800 ℃.Annealed from 700 to800 ℃,the dielectric constant and energy storage performance of PSNNS films are continuously ***,with annealing temperature up to 850 ℃,their dielectric constant decreases,which might be related with the removal of interfacial defects as a function of annealing *** is one of the causes of space charge phenomenon,resulting in the increase in dielectric ***,the micro structure analysis by X-ray diffraction(XRD) and transmission electron microscope(TEM) indicates that the change of crystallization phase and interfacial polarization takes responsibility to the results.

关键词： Thin film Pulse laser deposition Annealing temperature Energy storage density

Nanocavity enriched CuPd alloy with high selectivity for CO_(2) electroreduction toward C_(2)H_(4)

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Rare Metals 2024年第4期43卷 1513-1523页

作者： Ze-Yu Zhang Hai-Bin Wang fei-fei Zhang Jing-wei Li Xin-Zhuo hu Si-wei Yan Yi-Ming Bai Xun Zhang Gu-Rong Shen Peng-fei Yin Jing Yang Cun-Ku Dong Jing Mao hui Liu Xi-Wen Du Institute of New-Energy Materials School of Materials Science and EngineeringTianjin UniversityTianjin300350China

Electrocatalysis of CO_(2)reduction reaction is an effective way to convert CO_(2)into high value-added products,but the selectivity of Cu-based catalysts for C2+products needs to be improved due to the high energy barrier of C-C ***,a viable catalyst design strategy to decrease energy barrier of C-C coupling should be put ***,a nanocavity-enriched CuPd single atom alloy(CuPd SAA)catalyst is designed to promote CC coupling *** faradaic efficiency of CuPd SAA for ethylene and C_(2+)reaches 75.6%and 85.7%at-0.7 V versus reversible hydrogen electrode(RHE),*** on the results given by in situ characterization,the porous hollow structure dramatically increases the ratio of the linear-bond*CO,thus enhancing the faradaic efficiency for *** functional theory(DFT)calculation reveals that the Pd doping can regulate the electronic structure of neighboring Cu atoms to decrease the energy barrier of C-C coupling,further improving the faradaic *** work provides a new idea for designing catalyst with high selectivity for ethylene.

关键词： Adsorption configuration C-C coupling CO_(2) electrocatalysis Ethylene Single atom alloy

Investigation of mechanical and electrical characteristics of selfsensing pneumatic torsional actuators

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Science China(Technological Sciences) 2024年第1期67卷 130-142页

作者： XIAO wei hu DeAn hu GuoLiang XIAO Yihua Key Laboratory of Conveyance and Equipment Ministry of EducationEast China Jiaotong UniversityNanchang 330013China Key Laboratory of Advanced Design and Simulation Techniques for Special Equipment Ministry of EducationHunan UniversityChangsha 410082China

Soft pneumatic actuators are one of the most promising actuation for soft robots,and great achievements have been *** it remains challenging to endow sensing capabilities to pneumatic actuators,especially for the sensing ability originating directly from the actuator ***,a self-sensing pneumatic torsional actuator(SPTA)is designed based on the electromagnetic induction effect and magnetically responsive *** SPTA can generate feedback voltage and current with the deformation,in which the sensing function comes from its inherent *** investigate the mechanical and electrical characteristics,an experimental platform and a finite element model are established,*** find that the torsion angle and output torque increase in nonlinear with the actuating *** maximum torsion angle is 66.35°,which is 84.34%of that for the actuator fabricated by pure *** maximum output torque(24.9 N mm)improves by 23.19%compared with the actuator made by pure *** regards the electrical characteristics,the maximum feedback voltage and current are 2.90μV and 29.50 nA when the SPTA is actuated by a pressure of−40 *** also demonstrate that the relationship between the torsion angle and the magnetic flux change is approximately ***,the number of turns of wires,magnetic powders contents,and magnetic direction on the feedback voltage and current are *** show that the feedback voltage and current can be enhanced by increasing the number of turns and magnetic powders *** envision that the SPTA would be promising for soft robots to realize their accuracy control and intelligentization.

关键词： pneumatic torsional actuators self-sensing feedback voltage finite element modeling soft robots

Asymmetric Drying and Wetting Trends in Eastern and Western China

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Advances in Atmospheric Sciences 2024年第2期41卷 221-232页

作者： Wen WU fei JI Shujuan hu Yongli HE College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China

As an important factor that directly affects agricultural production, the social economy, and policy implementation,observed changes in dry/wet conditions have become a matter of widespread concern. However, previous research has mainly focused on the long-term linear changes of dry/wet conditions, while the detection and evolution of the non-linear trends related to dry/wet changes have received less attention. The non-linear trends of the annual aridity index, obtained by the Ensemble Empirical Mode Decomposition(EEMD) method, reveal that changes in dry/wet conditions in China are asymmetric and can be characterized by contrasting features in both time and space in China. Spatially, most areas in western China have experienced transitions from drying to wetting, while opposite changes have occurred in most areas of eastern China. Temporally, the transitions occurred earlier in western China compared to eastern China. Research into the asymmetric spatial characteristics of dry/wet conditions compensates for the inadequacies of previous studies, which focused solely on temporal evolution;at the same time, it remedies the inadequacies of traditional research on linear trends over centennial timescales. Analyzing the non-linear trend also provides for a more comprehensive understanding of the drying/wetting changes in China.

关键词： aridity index EEMD dry/wet conditions asymmetric evolution