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Physics-Informed Neural Networks with Two Weighted Loss Function Methods for Interactions of Two-Dimensional Oceanic Internal Solitary Waves

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Journal of Systems Science & Complexity 2024年第2期37卷 545-566页

作者： sun Junchao CHEN yong TANG Xiaoyan School of Mathematical Sciences Key Laboratory of Mathematics and Engineering Applications(Ministry of Education)&Shanghai Key Laboratory of PMMPEast China Normal UniversityShanghai 200241China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

The multiple patterns of internal solitary wave interactions(ISWI)are a complex oceanic *** remote sensing techniques indirectly detect these ISWI,but do not provide information on their detailed structure and ***,the authors considered a three-layer fluid with shear flow and developed a(2+1)Kadomtsev-Petviashvili(KP)model that is capable of describing five types of oceanic ISWI,including O-type,P-type,TO-type,TP-type,and *** learning models,particularly physics-informed neural networks(PINN),are widely used in the field of fluids and internal solitary ***,the authors find that the amplitude of internal solitary waves is much smaller than the wavelength and the ISWI occur at relatively large spatial scales,and these characteristics lead to an imbalance in the loss function of the PINN *** solve this problem,the authors introduce two weighted loss function methods,the fixed weighing and the adaptive weighting methods,to improve the PINN *** successfully simulated the detailed structure and dynamics of ISWI,with simulation results corresponding to the satellite *** particular,the adaptive weighting method can automatically update the weights of different terms in the loss function and outperforms the fixed weighting method in terms of generalization ability.

关键词： Internal solitary wave interactions KP equation PINN method weighted loss function method

Urban planning construction land standard and its revision based on climate and topography in China

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Journal of Geographical Sciences 2021年第4期31卷 603-620页

作者： XU yong ZHAO Shen FAN jie Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Urban planning construction land standard is the technical specification for scientifically allocating various types of urban construction land,and it is the basis for drawing up and revising the overall urban planning *** China’s current urban planning construction land standard,many problems exist,such as the gap in the land use control threshold,the lack of regional differences in the climate revision,and failing to consider the topographic *** resolve these problems,this study proposed a step-by-step process framework and quantitative calculation method for the establishment and revision of standards in accordance with the principle of Total-Structure *** setting the conditions,a universal basic standard for construction land was *** analysis was then conducted on the relationship between the basic standard and the selected key indicators,such as urban population size,sunshine spacing coefficient,the width of river valleys or inter-montane basins,and terrain slope,among ***,revised standards were formed for climate conditions,topography,and geomorphologic conditions,which were matched with the basic *** key results are three-fold:(1)The per capita construction land standard of 95 m~2/person can be used as the total indicator of China’s urban planning basic standard,and the corresponding per capita single construction land comprises 32.50%of residential land,7.42%of public management and public service land,22.50%of industrial land,17.50%of transportation facilities,12.50%of green space,and 7.58%of other land-use *** results of the revision of the urban population size indicate that the difference in population size has little effect on the total amount of per capita construction land.(2)The climate revision results of per capita residential land and per capita construction land in major cities reveal that the revised climate value varies greatly between north and south *** revised

关键词： urban planning construction land standard climate revision standard topography revision standard

Photo-induced macro/mesoscopic scale ion displacement in mixed-halide perovskites:ring structures and ionic plasma oscillations

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Light(Science & Applications) 2022年第10期11卷 2388-2398页

作者： Xiaoxiao sun yong Zhang Weikun Ge Laboratory for Thin Films and Photovoltaics Empa-Swiss Federal Laboratories for Materials Science and Technology8600 DuebendorfSwitzerland Department of Information Technology and Electrical Engineering ETH Zurich8093 ZurichSwitzerland Institute of Ion Beam Physics and Materials Research Helmholtz-Zentrum Dresden-RossendorfDresden 01328Germany Department of Electrical and Computer Engineering The University of North Carolina at CharlotteCharlotteNC 28223USA Department of Physics Tsinghua UniversityBeijing 10084People's Republic of China

Contrary to the common belief that the light-induced halide ion segregation in a mixed halide alloy occurs within the illuminated area,we find that the Br ions released by light are expelled from the illuminated area,which generates a macro/mesoscopic size anion ring surrounding the illuminated area,exhibiting a photoluminescence *** intriguing phenomenon can be explained as resulting from two counter-balancing effects:the outward diffusion of the light-induced free Br ions and the Coulombic force between the anion deficit and surplus *** after removing the illumination,the macro/mesoscopic scale ion displacement results in a built-in voltage of about 0.4 V between the ring and the ***,the displaced anions return to the illuminated area,and the restoring force leads to a damped ultra-low-frequency oscillatory ion motion,with a period of about 20-30 h and lasting over 100 *** finding may be the first observation of an ionic plasma oscillation in *** understanding and controlling the"ion segregation"demonstrate that it is possible to turn this commonly viewed"adverse phenomenon"into novel electronic applications,such as ionic patterning,self-destructive memory,and energy storage.

关键词： mixed removing return

Genome editing opens a new era for physiological study and directional breeding of fishes

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Science Bulletin 2017年第3期62卷 157-158页

作者： sun, yong-Hua State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhan China 430072

In recent years, the whole life science community has witnessed the advance and breakthrough in the genome editing technologies, including zinc-finger nucleases （ZFNs）, transcription activator-like effector （TALE） nucleases （TALENs） and clustered, regularly interspaced, short palindromic repeats （CRISPR）-CRISPR-associated （Cas） systems （CRISPR/Cas9） [1-3]. With these tools, scientists are able to introduce site-specific modifications in the genome of a wide range of organisms from invertebrates to vertebrates.

关键词：编辑技术基因组定向育种生理学无脊椎动物鱼类位点特异性生命科学

Recent Advances in Drilling Tool Temperature:A State‑of‑the‑Art Review

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Chinese Journal of Mechanical Engineering 2022年第6期35卷 23-62页

作者： Zhaoju Zhu Xinhui sun Kai Guo jie sun Jianfeng Li School of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350116China School of Mechanical Engineering Shandong UniversityJinan 250061China

Drilling is regarded as the most complex manufacturing process compared with other conventional machining *** the drilling process,most of the energy consumed in metal cutting is converted to heat and increases temperature *** resulting thermal phenomena are important since they influence the mode of deformation,the final metallurgical state of the machined surface,and the rate of tool ***,understanding the temperature characteristics in the drilling process is crucial for enhancing the drill performance and process *** efforts have been conducted to measure and control the drilling tool temperature ***,very few studies have been conducted from a comprehensive perspective to review all the *** address this gap in the literature,a rigorous review concerning the state-of-the-art results and advances in drilling tool temperature is presented in this paper by referring to the wide comparisons among literature *** multiple aspects of drilling tool temperature are precisely detailed and discussed in terms of theoretical analysis and thermal modeling,methods for temperature measuring,the effect of cutting parameters,tool geometries and hole-making methods on temperature and temperature controlling by different cooling *** conclusion,several possible future research directions are discussed to offer potential insights for the drilling community and future researchers.

关键词： Drilling Tool temperature Advance materials Cutting characteristics

A New Method for Solving Nonlinear Partial Differential Equations Based on Liquid Time-Constant Networks

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Journal of Systems Science & Complexity 2024年第2期37卷 480-493页

作者： sun Jiuyun DONG Huanhe FANG yong College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China

In this paper,physics-informed liquid networks(PILNs)are proposed based on liquid time-constant networks(LTC)for solving nonlinear partial differential equations(PDEs).In this approach,the network state is controlled via ordinary differential equations(ODEs).The significant advantage is that neurons controlled by ODEs are more expressive compared to simple activation *** addition,the PILNs use difference schemes instead of automatic differentiation to construct the residuals of PDEs,which avoid information loss in the neighborhood of sampling *** this method draws on both the traveling wave method and physics-informed neural networks(PINNs),it has a better physical ***,the KdV equation and the nonlinear Schr¨odinger equation are solved to test the generalization ability of the *** the best of the authors’knowledge,this is the first deep learning method that uses ODEs to simulate the numerical solutions of PDEs.

关键词： Nonlinear partial differential equations numerical solutions physics-informed liquid networks physics-informed neural networks

Design and experimental research of a sub-Newton N_(2)O monopropellant thruster with inner-heater

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Chinese Journal of Aeronautics 2022年第5期35卷 309-318页

作者： Kaiyang LI jie FANG Wei sun Bing sun Guobiao CAI School of Astronautics Beihang UniversityBeijing 100083China Key Laboratory of Spacecraft Design Optimization and Dynamic Simulation Technologies of Ministry of Education Beihang UniversityBeijing 100083China China Academy of Space Technology Beijing 100094China

Nitrous oxide(N_(2)O)is a green propellant with excellent application prospects.A subNewton N_(2)O monopropellant thruster with inner-heater and a N_(2)O self-pressurization stable supply system with regenerative heat compensation are designed in this *** experimental research of the thruster is described,including measurements of preheating power,activation temperature,vacuum thrust,specific impulse,life-span and pulsed operation *** inserting the heater into the catalyst-bed,preheating efficiency of the heater is significantly improved compared to the thruster with ***,the preheating power demand of the thruster is successfully reduced to around 10 *** mean vacuum thrust of 322 mN is attained and the corresponding specific impulse reaches 162s at the mass flow rate of 0.2 g/*** activation temperature of 523 K is achieved,and the activation performance of the thruster is affected by the loading factor.A long term hot-firing test longer than 12000 s is *** pulsed operation performance of the inner-preheating thruster is also studied by measuring chamber *** with different magnitudes are produced by adjusting the opening duration of the control valve.A minimum impulse of 81 mN·s is ***,the performance of the thruster is evaluated by comparison with other thrusters of the same *** results indicate that the proposed thruster with inner-heater is superior in terms of preheating power,activation temperature and specific impulse performance.

关键词： Green propellant Monopropellant thruster Nitrous oxide Regenerative heat compensation Self-pressurization

Microfluidic fuel cells integrating slanted groove micro-mixers to terminate growth of depletion boundary layer thickness

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第10期24卷 859-874页

作者： Jinchi sun Xiongwei TIAN Zhangqing LIU jie sun Menglian ZHENG Institute of Thermal Science and Power Systems College of Energy EngineeringZhejiang UniversityHangzhou 310027China Institute of Energy and Environment Engineering NingboTech UniversityNingbo 315100China State Key Laboratory of Clean Energy Utilization Hangzhou 310027China

Because of potential high energy densities,microfluidic fuel cells can serve as micro-scale power *** microfluidic fuel cells typically operate in the co-laminar flow regime to enable a membrane-less design,they generally suffer from severe mass transfer limitations with respect to diffusion *** address this issue,a novel channel design that integrates slanted groove micro-mixers on the side walls of the channel is *** modeling on the design of groove micro-mixers and grooveless design demonstrates a mass transfer enhancement that has a 115%higher limiting current density and well-controlled convective mixing between the oxidant and the fuel streams with the use of slanted groove ***,the growth of the thickness of the depletion boundary layer is found to be terminated within approximately 2 mm from the channel entrance,which is distinct from the constantly growing pattern in the grooveless *** addition,a simplified mass transfer model capable of modeling the mass transfer prFocess with the presence of the transverse secondary flow is ***,a dimensionless correlation is derived to analyze the effects of the design parameters on the limiting current *** present theoretical study paves the way towards an optimal design of a microfluidic fuel cell integrating groove micro-mixers.

关键词： Microfluidic Fuel cell Membraneless Slanted groove micro-mixer Mass transfer Depletion boundary layer

Formation of I1 stacking fault by deformation defect evolution from grain boundaries in Mg

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Journal of Magnesium and Alloys 2022年第10期10卷 2717-2729页

作者： yong-jie Hu Vaidehi Menon Liang Qi Department of Materials Science and Engineering University of MichiganAnn Arbor 48109USA Department of Materials Science and Engineering Drexel UniversityPhiladelphia 19104USA

I_(1)stacking faults(SFs)in Mg alloys are regarded as the nucleation sites ofdislocations that are critical for these alloys to achieve high *** it was proposed that the formation of I_(1)SFs requires the accumulations of a large number of vacancies,which are difficult to achieve at low *** this study,molecular dynamics(MD)and molecular statics(MS)simulations based on empirical interatomic potentials were applied to investigate the deformation defect evolutions from the symmetric tilt grain boundaries(GBs)in Mg and Mg-Y alloys under external loading along-*** results show the planar faults(PFs)on Pyramidal I planes first appear due to the nucleation and glide of(1/2 c+p)partial dislocations from GBs,where p=1/3(1010).These partial dislocations with pyramidal PFs interact with other defects,including pyramidal PFs themselves,GBs,and ppartial dislocations,generating a large amount of I_(1)*** analyses show the nucleation and growth of I_(1)SFs are achieved by atomic shuffle events and deformation defect reactions without the requirements of vacancy *** simulations also suggest the Y clusters at GBs can reduce the critical stress for the formation of pyramidal PFs and I_(1)SFs,which provide a possible reason for the experimental observations that Y promotes thedislocation activities.

关键词： Magnesium alloys I1 stacking faults dislocations Grain boundaries Defect nucleation and evolution Molecular dynamics simulations