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Ice lines as the origin for the gap/ring structure in protoplanetary disks: the issue of the assumed temperature profile

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Research in Astronomy and Astrophysics 2021年第7期21卷 91-98页

作者： yao Liu Purple Mountain Observatory&Key Laboratory for Radio Astronomy Chinese Academy of SciencesNanjing 210023China

Gaps and rings are commonly seen in recent high-resolution ALMA observations of protoplanetary disks. Ice lines of volatiles are one of the mechanisms proposed to explain the origin for these substructures. To examine the ice line hypothesis, literature studies usually parameterize the midplane temperature with the analytic formula of a passively heated, flared disk. The temperature in this simplified expression is basically dependent on the stellar luminosity. I have built a grid of self-consistent radiative transfer models that feature the same stellar properties, but different disk parameters. The midplane temperature of these models shows a large dispersion over a wide range of radii, indicating that besides the stellar luminosity, the disk parameters also play an important role in determining the thermal *** the mid-plane temperature from radiative transfer simulation with the analytic solution shows a large difference between both approaches. This result suggests that special care on the assumed temperature profile has to be taken in the analysis of gap/ring origins, and conclusions drawn in previous works on the basis of the analytic temperature should be revisited. I further took the AS 209 disk as an example, and conducted a detailed radiative transfer modeling of the spectral energy distribution and the ALMA Band 6 image. The D137, D24 and D9 gaps are associated with the ice lines of major volatiles in the disk according to such a thorough analysis. However, if the temperature profile simply follows the analytic formula, none of these gaps matches the ice lines of the species considered here.

关键词： protoplanetary disks radiative transfer stars:formation

A learning theory of meta learning

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National Science Review 2024年第8期11卷 9-10页

作者： Fang yao School of Mathematical Sciences Peking University

A key feature of human intelligence is the ability to transfer knowledge learned from multiple learning tasks to other similar but different ones. Namely, humans attempt to learn how to generalize, and thus they can tackle a continuous stream of learning tasks. Correspondingly, in real-world applications, it is always crucial to improve learning in a new task by leveraging knowledge transferred from related tasks that have already been learned.

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Disturbance observer based actor-critic learning control for uncertain nonlinear systems

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Chinese Journal of Aeronautics 2023年第11期36卷 271-280页

作者： Xianglong LIANG Zhikai yao yaowen GE Jianyong yao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China College of Artificial Intelligence Nanjing University of Post and TelecommunicationNanjing 210023China

This paper investigates the disturbance observer based actor-critic learning control for a class of uncertain nonlinear systems in the presence of unmodeled dynamics and time-varying *** proposed control algorithm integrates a filter-based design method with actor-critic learning architecture and disturbance observer to circumvent the unmodeled dynamic and the timevarying *** be specific,the actor network is employed to estimate the unknown system dynamic,the critic network is developed to evaluate the control performance,and the disturbance observer is leveraged to provide efficient estimation of the compounded disturbance which includes the time-varying disturbance and the actor-critic network approximation ***,highgain feedback is avoided and the improved tracking performance can be ***,a composite weight adaptation law for actor network is constructed by utilizing two types of signals,the cost function and the modeling ***,theoretical analysis demonstrates that the developed controller can guarantee bounded *** simulations and experiments on a robot manipulator are implemented to validate the performance of the resulted control strategy.

关键词： Actor-critic structure Composite adaptation Disturbance observer Robot manipulator Uncertain nonlinear system

Premature failure induced by non-equilibrium grain-boundary tantalum segregation in air-plasma sprayed ZrO_(2)-YO_(1.5)-TaO_(2.5)thermal barrier coatings

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International Journal of Minerals,Metallurgy and Materials 2022年第12期29卷 2189-2200页

作者： yao yao Di Wu Xiaofeng Zhao Fan Yang Shanghai Key Laboratory of Advanced High Temperature Materials and Precision Forming Shanghai Jiao Tong UniversityShanghai 200240China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

ZrO_(2)-YO_(1.5)-TaO_(2.5)(ZYTO)is a promising top-coat material for thermal barrier coatings(TBCs).The bulk properties of ZYTO have been reported by several studies,but its performances as TBCs are less-well *** this work,ZYTO TBCs were prepared by air plasma spraying(APS)and their thermal cycling performances were investigated at 1150℃.Despite of the good bulk properties,APS ZYTO TBCs present an extremely short thermal fatigue *** is attributed to the non-equilibrium grain-boundary segregation of TaO_(2.5) induced by limited solubility and rapid quenching during APS process,resulting in a tetragonal(t)to cubic(c)and metastable-tetragonal(tm)phase transformation in ZYTO *** volume shrinkage(~0.74vol%)of phase transformation leads to many cracks at the c/tm phase boundaries after *** the other hand,the formation of cubic phase with massive grain-boundary Ta segregation induces a large intergranular embrittlement and a weak bonding strength(~5.3 MPa),resulting in the premature failure of the ZYTO TBCs.

关键词： thermal barrier coatings air plasma spray tantalum segregation phase transformation

Energy variation in diffusive void nucleation induced by electromigration

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Acta Mechanica Sinica 2020年第4期36卷 866-872页

作者： Yuexing Wang yao yao Zhang Long Leon Keer Institute of Electronic Engineering China Academy of Engineering PhysicsMianyang 621999China School of Civil Engineering Xi'an University of Architecture and TechnologyXisan 710055China School of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical UniversityXi5an 710072China Department of Civil and Environmental Engineering Northwestern UniversityEvanstonIL 60208USA

An energy approach is proposed to describe electromigration induced void nucleation based on phase transformation *** chemical potential for an individual migrated atom is predicted by diffusion induced back stress equivalent *** determining the chemical potential for the dilfusing atoms,the Gibbs free energy controlling the void nucleation can be determined and the mass diffusion process is *** critical void radius and nucleation time are determined analytically when the Gibbs free energy approaches the extreme *** theoretical predictions are compared with the experimental results from literatures and show good *** proposed model can also be applied to other diffusion induced damage processes such as thermomigration and stress migration.

关键词： Energy Electromigration Void nucleation Diffusion

"Smoke Detector"of Human Diseases for Environmental Aerosol Exposure

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Chinese Journal of Chemistry 2022年第12期40卷 1471-1477,I0002页

作者： Maosheng yao State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

Air consists of various different pollutants(both biological and non-biological).COVID-19 pandemic further threatens the air *** exposure causes many diseases including asthma,respiratory infections and *** protein bi-omarker for early diagnosis often fails due to its lower level at the very beginning of a *** another front,different technologies were attempted for realtime monitoring of air ***,many aerosol exposures occur silently without any knowledge due to limitation of available analytical *** breath has emerged as a promising non-invasive sample for disease diagnosis,in-cluding cancer and *** recently,it was shown that rats emitted distinc-tive profile of volatile organic compounds(VOCs)within minutes when exposed to different air pollutants including ozone and *** the pandemic times,breath-borne VOC was also used to rapidly screen *** exposure could result in changes in metabolism,thus releasing different pat-terns of VOCs via breath within very short *** monitoring of exhaled biomarker profile could spot the early signs of a disease,thus offering an earlier *** array and machine learning together can lend a great hand toward such an *** mini review is undertaken to share such endeavors and inspire further innovations.

关键词： Bioaerosol Environmental aerosol exposure Breath biomarkerl Disease Detection Analytical Sensor

Mean-square estimate of automorphic L-functions

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Frontiers of Mathematics in China 2020年第1期15卷 205-213页

作者： Weili yao Department of Mathematics Shanghai UniversityShanghai 200444China

Let f be a holomorphic Hecke cusp form with even integral weight k≥2 for the full modular group,and letχbe a primitive Dirichlet character modulo *** Lf(s,χ)be the automorphic L-function attached to f andχ-We stud... 详细信息

关键词： Automorphic L-function cusp form Fourier coefficient

Why Can We Copy Classical Information？

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Chinese Physics Letters 2011年第1期28卷 30-31页

作者： SHEN yao Key Laboratory for Atomic and Molecular Nanosciences and Department of Physics Tsinghua University Beijing 100084 Tsinghua National Laboratory for Information Science and Technology Tsinghlza University Beijing 100084

It is pointed out that the noneloning theorem in quantum mechanics also holds for unknown state in linear classical physics. The apparent capability of copying of a classical state is essentially the capability of perfect measurement in classical physics. The difference in copying- between quantum and classical physics is the difference in measurement between the two theories. A classical copying process is the combined action of measurement of an unknown state and the preparation of this state onto another system. Hence perfect measurability in classical physics enables the copying of a classical state.

关键词： Physics Measurement

Self-adjustment of Carrying Capacity of Concrete Embedded with CFRC

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Journal of Materials Science & Technology 2006年第3期22卷 401-403页

作者： Wu yao School of Materials Science and Engineering Tongji University Shanghai 200092 China

By heating up the embedded carbon fiber reinforced cement based material （CFRC）, the carrying capacity and deformation of concrete member could be adjusted. The relationship between temperature difference and expansion strain of CFRC was demonstrated, and the temperature-deformation-load effect of concrete embedded with CFRC was studied. Heating the CFRC up to different temperatures resulted in different degree of inner pre-stress in concrete. Thus, the load capacity of concrete could be regulated owing to counteracting the pre-stress.

关键词： Carbon fiber Self-adjustment Concrete Pre-stress