检索结果-南通市图书馆

A module based modeling framework for estimating lunar dust deposition due to human activities

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 501-510页

作者： Chunjian pan College of Automation engineering Shanghai University of Electric PowerShanghai 200090China

Lunar dust is considered to be one of the top challenges for enabling humans to have extended stays on the *** activities such as module landings and launches,walking,rover operation and construction activities will inevitably produce a significant amount of ***,it is important to estimate the potential range and intensity of dust deposition caused by these activities to minimize dust accumulation over time and for maintenance planning and execution.A modular model that correlates the dust deposition distribution with initial mean dust particle velocity,its mean ejected angle and the total amount of ejected mass is developed for an elementary mechanical *** modular model is further employed to form a modeling framework to estimate dust deposition of a trajectory based activity of similar repeated movements such as the landing process of a lander,walking and rover *** model forms a unified modeling framework for different trajectory-based activities and is shown to predict consistent and physically meaningful ranges and intensities of dust deposition provided reliable data to calibrate the model parameters.

关键词： Lunar dust Dust deposition Lunar lander Lunar construction Model calibration

Analytical Solutions for an Isotropic elastic Half-Plane with Complete Surface effects Subjected to a Concentrated/Uniform Surface Load

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2024年第3期37卷 371-384页

作者： Xia-Hui pan School of Civil engineering Henan Polytechnic UniversityJiaozuo454003China

Within the context of Gurtin-Murdoch surface elasticity theory,closed-form analytical solutions are derived for an isotropic elastic half-plane subjected to a concentrated/uniform surface *** the effects of residual surface stress and surface elasticity are *** stress function method and Fourier integral transform technique are *** solutions are provided in a compact manner that can easily reduce to special situations that take into account either one surface effect or none at *** results indicate that surface effects generally lower the stress levels and smooth the deformation profiles in the *** elasticity plays a dominant role in the in-plane elastic fields for a tangentially loaded half-plane,while the effect of residual surface stress is fundamentally crucial for the out-of-plane stress and displacement when the half-plane is normally *** the remaining situations,combined effects of surface elasticity and residual surface stress should be *** results for a concentrated surface force serve essentially as fundamental solutions of the Flamant and the half-plane Cerruti problems with surface *** solutions presented in this work may be helpful for understanding the contact behaviors between solids at the nanoscale.

关键词： Surface effects Residual surface stress Surface elasticity Half-plane Analytical solutions

Aeroengine thrust estimation and embedded verification based on improved temporal convolutional network

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第1期37卷 106-117页

作者： Wanzhi MeNG Zhuorui pan Sixin WeN pan QIN Ximing SUN Key Laboratory of Intelligent Control and Optimization for Industrial equipment of Ministry of education Dalian University of TechnologyDalian 116024China School of Control Science and engineering Dalian University of TechnologyDalian 116024China

Thrust estimation is a significant part of aeroengine thrust control *** traditional estimation methods are either low in accuracy or large in *** further improve the estimation effect,a thrust estimator based on Multi-layer Residual Temporal Convolutional Network(M-RTCN)is *** solve the problem of dead Rectified Linear Unit(ReLU),the proposed method uses the Gaussian error Linear Unit(GeLU)activation function instead of ReLU in residual *** the overall architecture of the multi-layer convolutional network is adjusted by using residual connections,so that the network thrust estimation effect and memory consumption are further ***,the comparison with seven other methods shows that the proposed method has the advantages of higher estimation accuracy and faster convergence ***,six neural network models are deployed in the embedded controller of the micro-turbojet *** Hardware-in-the-Loop(HIL)testing results demonstrate the superiority of M-RTCN in terms of estimation accuracy,memory occupation and running ***,an ignition verification is conducted to confirm the expected thrust estimation and real-time performance.

关键词： Thrust estimation Temporal convolutional network embedded deployment Hardware-in-the-loop testing Ignition verification

Shape optimisation of basin insulator for DC gas insulated switchgear/gas insulated transmission lines based on artificial bee colony algorithm

在线全文

学校读者我要写书评

暂无评论

High Voltage 2024年第2期9卷 275-286页

作者： Yi Luo Shiyi Mao Ju Tang Zijun pan Cheng pan State Key Laboratory of Power Grid environmental Protection School of Electrical Engineering and AutomationWuhan UniversityWuhanChina

The surface charge accumulation on the basin insulator is a particular problem in high-voltage direct current(HVDC)gas insulated switchgears(GIS)and gas insulated trans-mission lines(GIL),which restricts the development and application of extra/ultra high-voltage(eHV/UHV)*** surface charge distribution and anti-flashover performance are closely related to the insulator *** obtain the optimal basin insulator,a shape optimisation model based on artificial bee colony algorithm was established,and the minimisation objective functions based on capacitive(initial)electric field distribution and resistive(steady-state)electric field distribution were respectively *** optimisation results of the two objective functions were calculated,and the electric field and charge distribution on the surface of the insulator before and after optimisation were evaluated and compared using the simulation *** results indicated that the optimisation based on the capacitive electric field can significantly inhibit the surface charge accumulation,and the optimised insulator can significantly reduce the surface normal electric field and make the distribution of the tangential electric field more uniform,and the maximum tangential electric field can be reduced by 10%;the optimisation based on resistive electric field can achieve similar results,but requires more computational *** on the results,the‘anti-charge’basin insulator structure suitable for the DC field was given.

关键词： insulator artificial charge

New opportunities for ferroelectric deep-UV nonlinear optical crystals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Materials 2024年第3期67卷 1004-1005页

作者： Miriding Mutailipu Shilie pan Research Center for Crystal Materials Xinjiang Technical Institute of Physics and ChemistryChinese Academy of SciencesUrumqi 830011China Center of Materials Science and Optoelectronics engineering University of Chinese Academy of SciencesBeijing 100049China

Deep-ultraviolet(deep-UV)light with the wavelength below200 nm is one of the most crucial elements of both laser-driven industrial and scientific applications in recent years[1].DeepUV light has been produced using a variety of techniques,such as gas discharge lamps,synchrotron radiation,excimer lasers,free electron lasers,and nonlinear frequency conversion.

关键词： nonlinear optical ferroelectric

Time-domain Differential Protection Based on Operating and Restraining Trajectory Indices for Lines Connecting Battery Storage energy Stations

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean energy 2024年第4期12卷 1074-1086页

作者： Yingyu Liang Cunyue pan School of Mechanical and electrical engineering China University of Mining and Technology(Beijing)BeijingChina

Battery energy storage stations(BeSSs)pose sever-al challenges for both phasor-based differential protection and the newly-proposed time-domain differential *** challenges include low sensitivity and even ***,the negative impact of various nonideal conditions,including current transformer(CT)saturation,errors,and outliers,on the security of differential protection remains an important *** by the aforementioned issues,this study ac-counts for the trajectory distribution discrepancy on Cartesian plane under various conditions and proposes a time-domain dif-ferential protection *** this paper,the trajectory formed by operating and restraining current samples is ***,after considering different operating states,the fault severity levels,and nonideal conditions,the variances in trajectory distribution between internal and external faults are extensively *** this basis,the Cartesian plane is divided into operating,uncertainty,and restraining ***-ther,the operating and restraining trajectory indices are meticu-lously designed and a protection criterion based on these indi-ces is formed to accurately separate internal faults from other events,unaffected by CT saturation,errors,and *** exceptional performance of the proposed protection method is extensively validated through PSCAD simulations and a hard-ware-in-the-loop testing *** the dependability,sensitivity,and security,the proposed protection method outper-forms three state-of-the-art differential protection methods.

关键词： Battery energy storage station time-domain differential protection operating trajectory index(OTI) restraining trajectory index(RTI)

A Time-Domain Numerical Simulation for Free Motion Responses of Two Ships Advancing in Head Waves

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean engineering 2024年第3期38卷 519-530页

作者： pan Su-yong CHeNG Yong School of Naval Architecture and Ocean engineering Jiangsu University of Science and TechnologyZhenjiang 212003China

The constant panel method within the framework of potential flow theory in the time domain is developed for solving the hydrodynamic interactions between two parallel ships with forward *** solving problems within a time domain framework,the free water surface needs to simultaneously satisfy both the kinematic and dynamic boundary conditions of the free water *** provides conditions for adding artificial damping *** the Runge−Kutta method to solve equations related to *** upwind differential scheme is used in the present method to deal with the convection terms on the free surface to prevent waves *** the comparison with the available experimental data and other numerical methods,the present method is proved to have good mesh convergence,and satisfactory results can be *** constant panel method is applied to calculate the hydrodynamic interaction responses of two parallel ships advancing in head *** simulations are conducted on the effects of forward speed,different longitudinal and lateral distances on the motion response of two modified Wigley ships in head *** further investigations are conducted on the effects of different ship types on the motion response.

关键词： ship motions time domain simulation forward speed different distances wave loads

Cooperative Target Fencing of Multiple Vehicles for a General Target with Connectivity Preservation and Collision Avoidance

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 136-151页

作者： pan Zini CHeN Ben M Department of Mechanical and Automation engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem for n-dimensional systems and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull formed by the ***,the dynamics of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the communication network and collision avoidance among the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a numerical example.

关键词： Multi-agent systems networked systems target fencing

Global Tangentially Analytical Solutions of the 3D Axially Symmetric Prandtl equations

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 2024年第4期45卷 573-596页

作者： Xinghong pan Chaojiang XU School of Mathematics and Key Laboratory of MIIT Nanjing University of Aeronautics and Astronautics Laboratoire de Mathématiques Rapha?l Salem UMR 6085 CNRSUniversité de Rouen Normandie

In this paper,the authors will prove the global existence of solutions to the three dimensional axially symmetric Prandtl boundary layer equations with small initial data,which lies in H1Sobolev space with respect to the normal variable and is analytical with respect to the tangential *** main novelty of this paper relies on careful constructions of a tangentially weighted analytic energy functional and a specially designed good unknown for the reformulated *** result extends that of Paicu-Zhang in[Paicu,*** Zhang,P.,Global existence and the decay of solutions to the Prandtl system with small analytic data,***.,241（1）,2021,403–446].from the two dimensional case to the three dimensional axially symmetric case,but the method used here is a direct energy estimates rather than Fourier analysis techniques applied there.

关键词： Axially symmetric Global existence Prandtl equations Tangentially analytical solutions