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Science China(Technological Sciences) 2024年第6期67卷 1893-1906页

作者： AN Kai WANG ZhenGuo huang Wei Hypersonic Technology Laboratory National University of Defense TechnologyChangsha410073China

We propose an adaptive learning-based optimal control scheme for height-velocity control models considering model uncertainties and external disturbances of hypersonic winged-cone *** longitudinal nonlinear model is first established and transformed into the control-oriented error equations,and the control scheme is organized by a steady-compensation *** overcome and eliminate the impact of model uncertainties and external disturbances,an adaptive radial basis function neural network(RBFNN)is designed by a q-gradient *** the height-velocity error system with estimated uncertainties into account,the adaptive learning-based optimal tracking control(ALOTC)scheme is proposed by combining the critic-only adaptive dynamic programming(ADP)framework and parameter optimization of system settling ***,a novel weight update law is proposed to satisfy the online iteration requirements,and the algorithm convergence and closedloop stability are discussed by the Lyapunov ***,four simulation cases are provided to prove the effectiveness,accuracy,and robustness of the proposed scheme for the hypersonic longitudinal control system.

关键词： optimal tracking control adaptive dynamic programming RBFNN hypersonic vehicle

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超声固结区域温度场分析及实验研究

振动．测试与诊断 2019年第1期39卷 191-196,230页

作者：王寅曹俊廖梦娇肖中扬张会霞黄卫清华侨大学机电及自动化学院厦门361021 南京航空航天大学航空宇航学院南京210016 广州大学机械与电气工程学院广州510006

温度是影响超声固结质量的重要因素,针对固结区域温度难以直接测量的现状,通过数值模拟研究工艺参数对固结温度的影响。首先,基于Hertz接触理论和Coulomb摩擦定律分析了固结区域的摩擦功,建立了固结区域的发热模型;其次,建立了钛铝箔材... 详细信息

温度是影响超声固结质量的重要因素,针对固结区域温度难以直接测量的现状,通过数值模拟研究工艺参数对固结温度的影响。首先,基于Hertz接触理论和Coulomb摩擦定律分析了固结区域的摩擦功,建立了固结区域的发热模型;其次,建立了钛铝箔材的超声固结三维热传导有限元模型,并且分析了主要工艺参数对固结区域温度场分布的影响;最后,为了验证模型的有效性,建立了超声固结加工温度测试平台,通过在基板埋植热电偶的方式测量固结时的温度,发现实验结果与数值仿真结果变化趋势一致,证实了模型的有效性。

关键词：超声固结有限元温度场热传导

Laminar Flame Structure-Dependent Exergy Destruction Behavior at Auto-Ignition Time Scale:A Case Study of Dimethyl Ether(DME)

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Journal of Thermal Science 2024年第4期33卷 1257-1271页

作者： WU Honghuan huang Wenlin ZHAO Hao SUN Wuchuan huang Zuohua ZHANG Yingjia State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong UniversityXi’an710049China

Hybrid deflagration/auto-ignition flame structures coexist in the combustion of advanced *** exergy destruction caused by different irreversible processes under varied flame regimes is thus important for understanding engine *** this study,the flame propagation modes for the premixed DME/air mixtures are numerically investigated under engine-relevant *** entropy generation and exergy destruction characteristics are compared under different flame *** reveal that as the typical premixed flame transition towards auto-ignition front,the exergy destruction from heat conduction and species mass diffusion gradually vanish and are dominated by chemical *** distributions of temperature and species mole fraction in the flame domain are analyzed to clarify the exergy destruction behaviors caused by heat conduction and mass ***,by dividing the DME oxidation process into four stages,the main reaction channels that contribute to the increase in exergy destruction from chemical reaction have been *** is found that the production and consumption of CH_(2)O and HO_(2) radical dominate the exergy destruction behavior during DME *** this basis,the kinetic mechanism of low-temperature chemistry causing greater exergy destruction is ***,low-temperature chemistry leads to significant exergy destruction due to(a)the large irreversibility of itself and(b)(mainly)the enhancement of H_(2)O_(2)loop reactions by low-temperature reaction *** the reduction of combustion irreversibility is promising to be achieved by reasonably regulating the fuel oxidation path.

关键词： exergy destruction flame structures entropy generation low-temperature chemistry DME

Shock-induced energy localization and reaction growth considering chemical-inclusions effects for crystalline explosives

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Defence Technology（防务技术） 2024年第3期33卷 278-294页

作者： Ruqin Liu Yanqing Wu Xinjie Wang Fenglei huang Xiaona huang Yushi Wen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Power and Mechanical Engineering Wuhan UniversityWuhan430072HubeiChina Institute of Chemical Materials China Academy of Engineering Physics(CAEP)Mianyang621999SichuanChina

Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains *** shock-induced energy localization,overall physical responses,and reactions in a-1,3,5-trinitro-1,3,5-triazinane(a-RDX)crystal entrained various chemical inclusions were investigated by the multi-scale shock technique implemented in the reactive molecular dynamics *** indicated that energy localization and shock reaction were affected by the intrinsic factors within chemical inclusions,i.e.,phase states,chemical compositions,and *** atomic origin of chemical-inclusions effects on energy localization is dependent on the dynamics mechanism of interfacial molecules with free space volume,which includes homogeneous intermolecular compression,interfacial impact and shear,and void collapse and *** introducing various chemical inclusions,the initiation of those dynamics mechanisms triggers diverse decay rates of bulk RDX molecules and hereby impacts on growth speeds of final *** chemical inclusions can reduce the effectiveness of the void during the shock *** the shockwave velocity of 9 km/s,the parent RDX decay rate in RDX entrained amorphous carbon decreases the most and is about one fourth of that in RDX with a vacuum void,and solid HMX and TATB inclusions are more reactive than amorphous carbon but less reactive than dry air or acetone *** lessdense shocking system denotes the greater increases in local temperature and stress,the faster energy liberation,and the earlier final reaction into equilibrium,revealing more pronounced responses to the present intense *** quantitative models associated with the relative system density(RD_(sys))were proposed for indicating energy-localization mechanisms and evaluating initiation safety in the shocked crystalline ***_(sys)is defined by the density ratio of defective RDX to perfec

关键词： Shock responses Energy localization Crystalline explosives Chemical inclusions Reactive molecular dynamics

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一种新型模态转换压电钻

压电与声光 2010年第5期32卷 770-773页

作者：杨淋丁庆军黄卫清赵淳生南京航空航天大学精密驱动研究所江苏南京210016

提出了一种新型模态转换压电钻。该压电钻将钻头斜向安装在定子基体上,形成一个纵弯模态转换器。利用压电陶瓷的逆压电效应使定子基体产生纵向振动并通过纵弯模态转换器将该纵向振动转换成钻头部分的局部弯振,从而在钻头端部合成为椭圆... 详细信息

提出了一种新型模态转换压电钻。该压电钻将钻头斜向安装在定子基体上,形成一个纵弯模态转换器。利用压电陶瓷的逆压电效应使定子基体产生纵向振动并通过纵弯模态转换器将该纵向振动转换成钻头部分的局部弯振,从而在钻头端部合成为椭圆运动,为切削及钻孔提供动力。利用有限元分析软件ANSYS对压电钻进行结构设计,仿真了钻头在设计工作频率下的切削轨迹。根据仿真结果试制了一台样机,对该样机进行了激光扫频实验,结果表明,样机工作频率为56kHz,切削频率可达336×104次/min,切削幅度则可控制在微米级。实验表明该样机配上普通牙钻,可在普通打印纸、硬纸板、铝板、钢板上进行切削、钻孔等操作。

关键词：模态转换压电钻椭圆运动逆压电效应

Cyclic Pulsating Pressure Enhanced Segregating Structuration of Ultra-High Molecular Weight Polyethylene/Graphene Composites as High-performance Light-Weight EMI Shields

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Chinese Journal of Polymer Science 2024年第7期42卷 958-967,I0008页

作者： Yun-Zhi huang Xiao-Xiao Liu Lan-Wei Li Guang-Ming huang Zhao-Xia huang Jin-Ping Qu National Engineering Research Center of Novel Equipment for Polymer Processing Key Laboratory of Polymer Processing EngineeringMinistry of EducationGuangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced ManufacturingSchool of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou 510641China School of Advanced Manufacturing Technology Guangdong Mechanical&Electrical PolytechnicGuangzhou 510550China

Currently,the enhancement in electromagnetic interference(EMI)performance of polymeric composite generally relies on either improving electrical conductivity(σ)for stronger electromagnetic(EM)reflections or tailoring structure for higher EM ***,we proposed a novel technique called cyclic pulsating pressure enhanced segregating structuration(CPP-SS),which can reinforce these two factors *** structural information was supplied by optical microscopy(OM)and scanning electron microscopy(SEM),both of which confirmed the formation and evolution of segregate structured ultra-high molecular weight polyethylene(UHMWPE)/graphene ***,the result showed that CPP-SS can significantly improve theσof ***,advanced specific EMI shielding efficiency of 31.1 d B/mm was achieved for UHMWPE/graphene composite at 1-mm thickness and a low graphene loading of 5 wt%.Meanwhile,it also confirmed that the intrinsic disadvantage of poor mechanical properties of conventional segregated structure composites can be *** work is believed to provide a fundamental understanding of the structural and performance evolutions of segregated structured composites prepared under CPPSS,and to bring us a simple and efficient approach for fabricating high-performance,strong and light-weight polymeric EMI shields.

关键词： Cyclic pulsating pressure Segregated structure Ultra-high molecular weight polyethylene Graphene Electromagnetic interface

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核电工程试验的过程控制

动力工程学报 2015年第4期35卷 336-340页

作者：郑红亮李聪顾国兴黄伟清上海核工程研究设计院上海200233 上海发电设备成套设计研究院上海200240

遵从核电质量保证对工程研究开发的规定,以及基于核电工程试验的实施过程具有质量保证中规定的"特殊过程"的基本特征,提出了核电工程试验成功的标志与主要准则.从试验目标和质量保证2个角度,明确了核电工程试验各个阶段的控制要素和进... 详细信息

遵从核电质量保证对工程研究开发的规定,以及基于核电工程试验的实施过程具有质量保证中规定的"特殊过程"的基本特征,提出了核电工程试验成功的标志与主要准则.从试验目标和质量保证2个角度,明确了核电工程试验各个阶段的控制要素和进行验证的要求.对试验设施可用性验证是试验过程控制的最重要环节,正式试验之前必须验证和确认试验模型特征量正确、关键参数测量准确、工况保障条件可控、质/能平衡测定合格和典型工况试验结果合理,以确保试验数据有足够的置信度.在国家大型先进压水堆核电站重大专项关键试验项目中,已全面实施了这种过程控制的相关程序,有效地促进了试验成功.

关键词：工程试验质量保证过程控制项目管理

Machine learning-assisted sparse observation assimilation for real-time aerodynamic field perception

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Science China(Technological Sciences) 2024年第5期67卷 1458-1469页

作者： ZHAO QingYu huang Jun GUO YuXin PAN YuXuan JI JingJing huang YongAn State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Accurate aerodynamic distribution perception and real-time flight state evaluation are crucial for flight safety,e.g.,stall ***,the observations are usually sparse due to limitations in sensor mounting space and cost,and a reconstruction technology is urgently ***,a machine learning-assisted assimilation method based on sparse observations has been *** from the traditional reconstruction methods focusing on boundary condition correction,the proposed method formulates the flow field pressure distribution as a linear superposition of flow field modes,thereby forming a real-time reconstruction pattern that combines offline modal extraction using computational fluid dynamics(CFD)with real-time determination of modal weights using a neural *** this study,CFD simulations were conducted under 800different operating conditions for common modal extraction and model *** weights of these modes were determined online based on merely five observations for reconstructing the full pressure field.A pressure reconstruction with a relative error of 6.1%and a mean square error of 0.003 was achieved within the prescribed condition *** computational cost was just2 ms for each reconstruction run,significantly faster than the 20 min required by the classical reconstruction ensemble transform Kalman *** also showed that the method maintains almost the same accuracy amidst 1.5%measurement *** practical examples,shock waves and the change of lift coefficient were analyzed using the proposed method,providing remarkable evidence for the capability of the method in supporting stall *** validate the method’s effectiveness and explore its potential in real-time and accurate monitoring of an aircraft.

关键词： aerodynamic force sparse observation neural networks pressure field reconstruction

Superiority of a Convolutional Neural Network Model over Dynamical Models in Predicting Central Pacific ENSO

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Advances in Atmospheric Sciences 2024年第1期41卷 141-154页

作者： Tingyu WANG Ping huang Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The application of deep learning is fast developing in climate prediction,in which El Ni?o–Southern Oscillation(ENSO),as the most dominant disaster-causing climate event,is a key *** studies have shown that deep learning methods possess a certain level of superiority in predicting ENSO *** present study develops a deep learning model for predicting the spatial pattern of sea surface temperature anomalies(SSTAs)in the equatorial Pacific by training a convolutional neural network(CNN)model with historical simulations from CMIP6 *** with dynamical models,the CNN model has higher skill in predicting the SSTAs in the equatorial western-central Pacific,but not in the eastern *** CNN model can successfully capture the small-scale precursors in the initial SSTAs for the development of central Pacific ENSO to distinguish the spatial mode up to a lead time of seven months.A fusion model combining the predictions of the CNN model and the dynamical models achieves higher skill than each of them for both central and eastern Pacific ENSO.

关键词： ENSO diversity deep learning ENSO prediction dynamical forecast system

Modulating the electrode–electrolyte interface enables switchable selectivity in electrocatalytic furfural reduction

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Science China Chemistry 2024年第10期67卷 3193-3194页

作者： Jingfang Zhang Yi huang Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education School of Chemical Engineering&PharmacyWuhan Institute of TechnologyWuhan 430205China College of Chemistry Central China Normal UniversityWuhan 430079China

Furfural(FF),an important bio-based platform molecule,can be valorized to high-value-added chemicals(e.g.,furfuryl alcohol(FA)or 2-methylfuran(MF))through catalytic hydrogenation[1].The traditional thermocatalytic transformation of FF always requires high-temperature and highpressure conditions[2].Accordingly,electrocatalytic hydrogenation is emerging as a promising approach for the selective reduction of FF to FA or MF under environmentally friendly and benign conditions.

关键词： hydrogenation electrolyte selectivity