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Evapotranspiration of a Populus euphratica forest during the growing season in an extremely arid region of northwest China using the Shuttleworth–Wallace model

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Journal of Forestry Research 2016年第4期27卷 879-887页

作者： Guanlong Gao Xiaoyou Zhang tengfei Yu Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Thus far, measurements and estimations of actual evapotranspiration（ET） in extremely arid areas are still insufficient. Based on successive observations from June–September 2014, we simulated ET of a Populus euphratica Oliv. forest during the growing season in an extremely arid region of northwest China using the Shuttleworth–Wallace（S–W） model. Simulated ET values were compared to those of the eddy-covariance（EC） method on a 1 h interval. With a root mean square error（RMSE）,relative error（RE） and mean absolute error（MAE） of0.192, 3.100 and 0.165 mm h-1, respectively, model performance was not satisfactory. In particular, on days with strong winds（Sep. 11–13）, deviations between simulated and observed ET values increased to 0.275, 0.878 and0.251 mm h-1, RMSE, RE and MAE respectively. These values were significantly greater than those in other study periods and were most likely owing to sharp increases in wind speed. As a result, there were substantial advective effects, which is not consistent with the assumption of the S–W model that there are no advective effects or mesoscale circulation patterns induced by surface discontinuities.

关键词： Wallace extremely satisfactory northwest absolute season successive insufficient sharp assumption

New Results in Stabilization of Uncertain Nonholonomic Systems:An Event-Triggered Control Approach

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Journal of Systems Science & Complexity 2021年第5期34卷 1953-1972页

作者： LIU tengfei ZHANG Pengpeng WANG Mengxi JIANG Zhong-Ping State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110004China. Department of Electrical and Computer Engineering New York University370 Jay StreetBrooklynNY 11201USA

This paper reports latest developments in event-triggered and self-triggered control of uncertain nonholonomic systems in the perturbed chained *** order to tackle the effects of drift uncertain nonlinearities,nonholonomic constraints and nonsmooth aperiodic sampling in eventbased control,a novel systematic design scheme is proposed by integrating set-valued maps with stateseparation and state-scaling *** stability analysis of the closed-loop event-triggered control system is based on the cyclic-small-gain techniques that overcome the limitation of Lyapunov theory in the construction of Lyapunov functions for nonsmooth dynamical systems and enjoy inherent robustness properties due to the use of gain-based characterization of robust *** specifically,the closed-loop event-triggered control system is transformed into an interconnection of multiple input-tostate stable systems,to which the cyclic-small-gain theorem is applied for robust stability *** self-triggered mechanisms are also developed as natural extensions of the event-triggered control *** proposed event-based control design approach is new and original even when the system model is reduced to the ideal unperturbed chained ***,the proposed methodology is also applicable to a broader class of nonholonomic systems subject to state and input-dependent *** efficacy of the obtained event-triggered controllers is validated by a benchmark example of mobile robots subject to parametric uncertainties and a measurement noise such as bias in the orientation.

关键词： Event-triggered control nonholonomic systems self-triggered control stabilization

Comparison of adaptive structural damage identification techniques in nonlinear hysteretic vibration isolation systems

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Earthquake Engineering and Engineering Vibration 2013年第4期12卷 659-667页

作者： Mu tengfei Zhou Li Jann N.Yang State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Department of Civil and Environmental Engineering University of California

Early structural damage identification to obtain an accurate condition assessment can assist in the reprioritization of structural retrofitting schedules in order to guarantee structural safety. Nowadays, seismic isolation technology has been applied in a wide variety of infrastructure, such as buildings, bridges, etc., and the health conditions of these nonlinear hysteretic vibration isolation systems have received considerable attention. To effectively detect structural damage in vibration isolation systems based on vibration data, three time-domain analysis techniques, referred to as the adaptive extended Kalman filter （AEKF）, adaptive sequential nonlinear least-square estimation （ASNLSE） and adaptive quadratic sum-sqnares error （AQSSE）, have been investigated. In this research, these analysis techniques are compared in terms of accuracy, convergence and efficiency, for structural damage detection using experimental data obtained through a series of laboratory tests based on a base-isolated structural model subjected to E1 Centro and Kobe earthquake excitations. The capability of the AEKF, ASNLSE and AQSSE approaches in tracking structural damage is demonstrated and compared.

关键词： structural health monitoring parameter identification damage tracking nonlinear hysteretic system experimental verification

Preface——Special Issue on New Directions in Nonlinear and Distributed Control

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Journal of Systems Science & Complexity 2018年第1期31卷 1-3页

作者： LIU tengfei XIN Bin JIANG Zhong-Ping State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang 110819 China School of Automation State Key Laboratory of Intelligent Control and Decision of Complex Systems Beijing Advanced Innovation Center for Intelligent Robots and Systems Beijing Institute of Technology Beijing 100081 China Tandon School of Engineering New York University Brooklyn NY 11201 USA

Nonlinearity is ubiquitous in engineering and natural *** development of nonlinear control can be traced back to decades *** date,the research has reached the stage that emphasizes developing methodologies that can ha... 详细信息

关键词：控制问题非线性分布式工程应用程序电子物理自然系统生产线相互作用

Interannual modulation of intraseasonal sea level variability along the southern coast of Java

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Science China Earth Sciences 2018年第1期61卷 1-12页

作者： CAO GuoJiao HE YiJun WEI ZeXun XU tengfei School of Marine Sciences Nanjing University of Information Science & Technology Nanjing 210044 China First Institute of Oceanography State Oceanic Administration Qingdao 266061 China Laboratory for Regional Oceanography and Numerical Modeling Qingdao National Laboratory for Marine Science and Technology Qingdao 266237 China jiangsu Research Center for Ocean Survey and Technology Nanjing 210044 China

The intraseasonal variability(ISV) of sea level anomalies(SLAs) along the southern coast of Java and its interannual modulation were studied based on a gridded SLA product produced from the Archiving, Validation, and Interpretation of Satellite Oceanography dataset. This ISV is induced by the propagation of intraseasonal Kelvin waves derived from the central equatorial Indian Ocean(EIO). Wavelet analysis and empirical mode decomposition of intraseasonal SLAs along the southern coast of Java showed interannual variability, with weaker ISV events during El Ni years and positive Indian Ocean Dipole(IOD) years than during normal years. This interannual modulation of the ISV is influenced by the El Ni-Southern Oscillation teleconnection via the Walker Circulation and eastern Indian Ocean upwelling connected to IOD events. The anomalously weaker Walker Circulation during El Ni events generates anomalous surface easterlies over the central-eastern tropical Indian Ocean that produce upwelling Kelvin waves in the EIO and offshore water transport along the southern coasts of Sumatra and Java, resulting in negative SLAs along the southern coast of Java. These negative SLAs damp the positive SLAs induced by the eastward propagation of downwelling Kelvin waves from the central EIO during the following March–May of El Ni years. Similar features of SLAs and sea surface wind anomalies also occur during positive IOD years. Consequently, the sea level ISV along the southern coast of Java is weaker in El Ni and positive IOD years.

关键词： Intraseasonal variability Sea level Interannual variability Kelvin waves Indian Ocean

Wind-forced equatorial wave dynamics of the Pacific Ocean during 2014/2015 and 2015/2016 E1 Nino events

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Journal of Oceanology and Limnology 2020年第4期38卷 1123-1137页

作者： WANG Jing YUAN Dongliang XU tengfei ZHAO Xia CAS Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao 266071China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China

The equatorial wave dynamics of interannual sea level variations between 2014/2015 and2015/2016 El Nino events are compared using the Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics,Institute of Atmospheric Physics Climate Ocean Model(LICOM) forced by the National Centers for Environmental Prediction(NCEP) reanalysis I wind stre s s and heat flux during *** addition,the LICOM can reproduce the interannual variability of sea surface temperature anomalies(SSTA) and sea level anomalies(SLA) along the equator over the Pacific Ocean in comparison with the Hadley center and altimetric data *** extracted the equatorial wave coefficients of LICOM simulation to get the contribution to SLA by multiplying the meridional wave *** 2014/2015 El Nino event,upwelling equatorial Kelvin waves from the western boundary in April2014 reach the eastern Pacific Ocean,which weakened SLA in the eastern Pacific ***,no upwelling equatorial Kelvin waves from the western boundary of the Pacific Ocean could reach the eastern boundary during the 2015/2016 El Nino *** wave model results also demonstrate that upwelling equatorial Kelvin waves in both 2014/2015 and 2015/2016 from the western boundary can reach the eastern ***,the contribution from stronger westerly anomalies forced downwelling equatorial Kelvin waves overwhelmed that from the upwelling equatorial Kelvin waves from the western boundary in ***,the western boundary reflection and weak westerly wind burst inhibited the growth of the 2014/2015 El Nino *** disclosed equatorial wave dynamics are important to the simulation and prediction of ENSO events in future studies.

关键词： Pacific Ocean equatorial waves western boundary reflection El Niño

Micro Morphology of Soot Particles Sampled from High Pressure Jet Flames of Diesel from Direct Coal Liquefaction

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Journal of Thermal Science 2022年第6期31卷 2155-2170页

作者： WANG tengfei QIAO Xinqi LI Tie WU Gang WANG Xinran Key Laboratory of Power Machinery and Engineering Ministry of EducationShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Merchant Marine College Shanghai Maritime UniversityShanghai 201306China

Diesel from direct coal liquefaction(DDCL) is a new type of engine alternative energy. But its hydrocarbon composition and physicochemical properties are quite different from those of Petro diesel. In this study, a premixed constant volume combustion chamber(CVCC) system with soot particle sampling devices was built. The soot particles in the spray flame were sampled and photographed by thermophoresis probe and transmission electron microscope(TEM). An automatic processing code based on Matlab software was developed to process the TEM images and extract the micro morphology parameters of the soot particles. This study has systematically studied the effects of sampling location, injection pressure, ambient density and oxygen concentration on the micro morphology of soot particles. The ambient density refers to the initial gas density in the CVCC. The results showed that various morphologies and sizes of soot particles coexisted in the upstream of the spray flame. During the evolution of soot particles from upstream to downstream in the flame, the size of soot aggregates gradually decreased, while the maturity of soot aggregates increased. With the increase of injection pressure, ambient density and oxygen concentration, the average sizes of soot aggregates and primary soot particles decreased, but the fractal dimensions of soot aggregates increased gradually. Under the same combustion condition and in-flame sampling location, the average projection area, gyration radius and primary soot diameter of soot aggregates produced by DDCL were significantly lower than those of Petro diesel. The structure of soot particles from DDCL was more compact than that of Petro diesel.

关键词： diesel from direct coal liquefaction in-flame sampling soot morphology TEM

Ion transporters: emerging agents for anticancer therapy

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Science China Chemistry 2022年第7期65卷 1265-1278页

作者： tengfei Yan Xin Zheng Shengda Liu Yingping Zou Junqiu Liu State Key Laboratory of Powder Metallurgy College of Chemistry and Chemical EngineeringCentral South UniversityChangsha 410083China College of Material Chemistry and Chemical EngineeringKey Laboratory of Organosilicon Chemistry and Material TechnologyMinistry of EducationKey Laboratory of Organosilicon Material Technology of Zhejiang ProvinceHangzhou Normal UniversityHangzhou 311121China

Natural ion channels are pore-forming proteins that allow ions to pass through biomembranes, playing pivotal roles in almost all facets of cellular physiological functions. Biomimetic ion transporters were initially investigated for the purpose of treating lifethreatening channelopathies. Recent studies have indicated that membrane-active synthetic ionophores possess desirable anticancer bioactivity against diverse cancer cell lines by disturbing intracellular ion homeostasis, triggering oxidative stress, and inducing apoptosis in tumors. Recent progress on ionophore-related antitumor therapeutics is comprehensively summarized in this review, including the molecular design principles, functional mechanisms, and characterization methods. Finally, we conclude this review by discussing the future opportunities and challenges in this field. It is anticipated that this review will provide an existing panoramic sketch and future directions toward the construction of novel ion transporters with simplified preparation procedures, enhanced biocompatibility, and desirable anti-proliferative activities, which may further accelerate their therapeutic applications in clinical treatments.

关键词： ion transporter ion homeostasis apoptosis anticancer treatment

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Physics-informed deep learning for solving phonon Boltzmann transport equation with large temperature non-equilibrium

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npj Computational Materials 2022年第1期8卷 245-254页

作者： Ruiyang Li Jian-Xun Wang Eungkyu Lee tengfei Luo Department of Aerospace and Mechanical Engineering University of Notre DameNotre DameIN46556USA Department of Electronic Engineering Kyung Hee UniversityYongin-siGyeonggi-do17104South Korea Department of Chemical and Biomolecular Engineering University of Notre DameNotre DameIN46556USA Center for Sustainable Energy of Notre Dame(ND Energy) University of Notre DameNotre DameIN46556USA

Phonon Boltzmann transport equation(BTE)is a key tool for modeling multiscale phonon transport,which is critical to the thermal management of miniaturized integrated circuits,but assumptions about the system temperatures(i.e.,small temperature gradients)are usually made to ensure that it is computationally *** include the effects of large temperature non-equilibrium,we demonstrate a data-free deep learning scheme,physics-informed neural network(PINN),for solving stationary,mode-resolved phonon BTE with arbitrary temperature *** scheme uses the temperature-dependent phonon relaxation times and learns the solutions in parameterized spaces with both length scale and temperature gradient treated as input *** experiments suggest that the proposed PINN can accurately predict phonon transport(from 1D to 3D)under arbitrary temperature ***,the proposed scheme shows great promise in simulating device-level phonon heat conduction efficiently and can be potentially used for thermal design.

关键词： phonon equilibrium equation