检索结果-南通市图书馆

维普期刊数据库博看期刊

同方期刊数据库

发挥蝙蝠翼高频脉冲特性的微结构线宽超分辨测量方法

在线全文

学校读者我要写书评

暂无评论

光学学报 2024年第13期44卷 137-144页

作者：徐志毅范筱昕张佳乐周圣航郭珍艳朱丹高志山袁群南京理工大学电子工程与光电技术学院江苏南京210094

白光显微干涉是阶跃型微结构三维形貌无损测量的经典方法,但其低通滤波特性使阶跃边缘本应突变的三维形貌被平滑,导致边缘定位困难,影响线宽参数的计算提取。当微结构深度在光源相干长度内时,蝙蝠翼效应使阶跃边缘处的复原形貌产生尖锐... 详细信息

白光显微干涉是阶跃型微结构三维形貌无损测量的经典方法,但其低通滤波特性使阶跃边缘本应突变的三维形貌被平滑,导致边缘定位困难,影响线宽参数的计算提取。当微结构深度在光源相干长度内时,蝙蝠翼效应使阶跃边缘处的复原形貌产生尖锐脉冲。蝙蝠翼脉冲是三维形貌中的伪信号,但其高频特性更利于阶跃边缘的识别。微结构线宽为两阶跃边缘各自对应蝙蝠翼脉冲高度峰值位置的间距。然而,三维形貌空间采样频率受成像艾里斑和探测器像素大小限制,在线宽测量方向上通常仅有数个像素点受蝙蝠翼效应影响,通过蝙蝠翼脉冲高度峰值定位,线宽测量精度仅有像素级别。本文建立了针对蝙蝠翼效应及其离散采样特性的白光干涉信号数值仿真模型,发掘了线宽正交方向上样品阶跃边缘形貌的空域缓变特性,等效提高了蝙蝠翼脉冲在该方向的采样频率。据此提出了一种基于蝙蝠翼高度峰值位置高精度定位的微结构线宽超分辨白光干涉测量方法,并依据实测条件分析了样品位姿对测量精度的影响。以RSN标定板为样品,采用成像艾里斑半径约为0.590μm的测量系统,利用本文方法实测标定线宽2~6μm的光栅区域线宽结果与标定值偏差小于0.021μm,实验结果证明,该方法可以实现远高于系统横向分辨率的线宽超分辨测量。

关键词：线宽测量超分辨白光干涉蝙蝠翼效应信号采样

Liquid crystal integrated metalens with tunable chromatic aberration

在线全文

学校读者我要写书评

暂无评论

Advanced Photonics 2020年第3期2卷 35-41页

作者： Zhixiong Shen shenghang zhou Xinan Li Shijun Ge Peng Chen Wei Hu Yanqing Lu Nanjing University College of Engineering and Applied SciencesNational Laboratory of Solid State MicrostructuresKey Laboratory of Intelligent Optical Sensing and ManipulationCollaborative Innovation Center of Advanced MicrostructuresNanjingChina Jiangsu Industrial Technology Research Institute Institute for Smart Liquid CrystalsChangshuChina

Overcoming chromatic aberrations is a vital concern in imaging systems in order to facilitate fullcolor and hyperspectral *** contrast,large dispersion holds opportunities for spectroscopy and *** both functions into a single component will significantly enhance its versatility.A strategy is proposed to delicately integrate two lenses with a static resonant phase and a switchable geometric phase *** former is a metasurface lens with a linear phase *** latter is composed of liquid crystals(LCs)with space-variant orientations with a phase profile that is frequency *** this means,a broadband achromatic focusing from 0.9 to 1.4 THz is *** a saturated bias is applied on LCs,the geometric phase modulation vanishes,leaving only the resonant phase of the ***,the device changes from achromatic to ***,a metadeflector with tunable dispersion is demonstrated to verify the universality of the proposed *** work may pave a way toward active metaoptics,promoting various imaging applications.

关键词： active metalens liquid crystals chromatic aberration imaging terahertz

Parallel Physics-Informed Neural Networks Method with Regularization Strategies for the Forward-Inverse Problems of the Variable Coefficient Modified KdV Equation

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2期37卷 511-544页

作者： zhou Huijuan School of Science Shanghai Maritime UniversityShanghai 201306China

This paper mainly introduces the parallel physics-informed neural networks(PPINNs)method with regularization strategies to solve the data-driven forward-inverse problems of the variable coefficient modified Korteweg-de Vries(VC-MKdV)*** the forward problem of the VC-MKdV equation,the authors use the traditional PINN method to obtain satisfactory data-driven soliton solutions and provide a detailed analysis of the impact of network width and depth on solving accuracy and ***,the author finds that the traditional PINN method outperforms the one with locally adaptive activation functions in solving the data-driven forward problems of the VC-MKdV *** for the data-driven inverse problem of the VC-MKdV equation,the author introduces a parallel neural networks to separately train the solution function and coefficient function,successfully addressing the function discovery problem of the VC-MKdV *** further enhance the network’s generalization ability and noise robustness,the author incorporates two regularization strategies into the *** amount of numerical experimental data in this paper demonstrates that the PPINNs method can effectively address the function discovery problem of the VC-MKdV equation,and the inclusion of appropriate regularization strategies in the PPINNs can improves its performance.

关键词： Data-driven forward-inverse problems parallel physics-informed neural networks regularization strategies variable coefficient modified KdV equation

Influence of stearic acid surface modification on flowability and agglomeration of battery grade Li_(2)CO_(3)powder

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第9期92卷 263-277页

作者： Ming zhou Lithium Industry Center Zhejiang New Era Zhongneng Technology Co.Ltd.Shaoxing312000China

This work investigates the flow and agglomeration behaviors of battery grade Li_(2)CO_(3)powder and the influence of stearic acid surface *** degree of agglomeration is directly related to the uniformity of Li_(2)CO_(3)and its powder *** to the Chinese National Nonferrous Metal Industry Standard,battery grade Li_(2)CO_(3)powder has D50 equal to 3–8μm which belongs to a micron-sized superfine ***,with the extension of storage time,the serious agglomeration phenomenon occurs due to the large specific surface area and rough and irregular powder *** Hausner ratio(HR)of the unmodified sample increases from 1.14 to 1.41,and the corresponding flowability is classified as good to ***,among samples with doping stearic acid,the optimum amount of it is 0.10 wt%which exhibits an extremely stable HR value from 1.14 to ***,after 156 days,the repose angle(AR)obtained for samples without surface modification and using 0.10 wt%stearic acid are calculated to be 49°and 28°,*** on the values of HR and AR,the flowability of the unmodified sample is poor while the sample modified with 0.10 wt%of stearic acid still maintain excellent powder flow ***,The LiMn_(2)O_(4)cathode material synthesized from modified Li_(2)CO_(3)powder with a stearic acid content of 0.10 wt%exhibits good crystallinity and comparable electrochemical performance to that prepared by commercial Li_(2)CO_(3).These results indicate that stearic acid has the potential to be an ideal modifier for battery grade Li_(2)CO_(3)powder that needs to be kept for a long time.

关键词： Battery grade Li_(2)CO_(3)powder Flowability Surface modification Stearic acid

Phase field modeling of ferroelastic variant switching in yttria-stabilized t'zirconia with strain gradient elasticity and interface tension

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(Technological Sciences) 2024年第5期67卷 1443-1457页

作者： zhou QianQian WEI YueGuang zhou YiChun YANG Li College of Engineering BIC-ESATPeking UniversityBeijing100871China School of Advanced Materials and Nanotechnology Xidian UniversityXi’an710126China Frontier Research Center of Thin Films and Coatings for Device Applications Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an710126China

The 6–8 wt%yttria-stabilized zirconia with a tetragonal structure(t’-YSZ)is extensively employed in thermal barrier *** exceptional fracture toughness of t’-YSZ can be attributed to its distinctive ferroelastic toughening *** and interface tension play a critical role in ferroelastic variant switching at the micro-and *** paper presents an original thermodynamically consistent phase field(PF)theory for analyzing ferroelastic variant switching at the micro-and nano-scale of t’-*** theory incorporates strain gradient elasticity using higher-order elastic energy and interface tension tensor via geometric nonlinearity to represent biaxial tension resulting from interface ***,a mixed-type formulation is employed to implement the higher-order theory through the finite element *** an interface in equilibrium,the effects of strain gradient elasticity result in a more uniform distribution of stresses,whereas the presence of interface tension tensor significantly amplifies the stress magnitude at the *** introduction of an interface tension tensor increases the maximum value of stress at the interface by a factor of 4 to *** nucleation and evolution of variants at a pre-existing crack tip in a mono-phase t’-YSZ have also been *** strain gradient elasticity is capable of capturing the size effect of ferroelastic variant switching associated with microstructures in ***,when the grain size approaches that of the specimen,the critical load required for variant switching at the crack tip increases,resulting in greater dissipation of elastic energy during ferroelastic variant ***,the interface tension accelerates the evolution of *** presented framework exhibits significant potential in modeling ferroelastic variant switching at the micro-and nano-scale.

关键词： thermodynamics strain gradient elasticity interface tension phase field method ferroelastic variant switching

Deep-reinforcement-learning-based UAV autonomous navigation and collision avoidance in unknown environments

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第3期37卷 237-257页

作者： Fei WANG Xiaoping ZHU zhou zhou Yang TANG School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

In some military application scenarios,Unmanned Aerial Vehicles(UAVs)need to perform missions with the assistance of on-board cameras when radar is not available and communication is interrupted,which brings challenges for UAV autonomous navigation and collision *** this paper,an improved deep-reinforcement-learning algorithm,Deep Q-Network with a Faster R-CNN model and a Data Deposit Mechanism(FRDDM-DQN),is proposed.A Faster R-CNN model(FR)is introduced and optimized to obtain the ability to extract obstacle information from images,and a new replay memory Data Deposit Mechanism(DDM)is designed to train an agent with a better *** training,a two-part training approach is used to reduce the time spent on training as well as retraining when the scenario *** order to verify the performance of the proposed method,a series of experiments,including training experiments,test experiments,and typical episodes experiments,is conducted in a 3D simulation *** results show that the agent trained by the proposed FRDDM-DQN has the ability to navigate autonomously and avoid collisions,and performs better compared to the FRDQN,FR-DDQN,FR-Dueling DQN,YOLO-based YDDM-DQN,and original FR outputbased FR-ODQN.

关键词： Faster R-CNN model Replay memory Data Deposit Mechanism(DDM) Two-part training approach Image-based Autonomous Navigation and Collision Avoidance(ANCA) Unmanned Aerial Vehicle(UAV)

Oxidation of emerging organic contaminants by in-situ H_(2)O_(2) fenton system

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2024年第3期9卷 417-434页

作者： Yuqin Ni Chuxiang zhou Mingyang Xing Yi zhou State Environmental Protection Key Lab of Environmental Risk Assessment and Control on Chemical Processes School of Resources&Environmental EngineeringEast China University of Science and TechnologyShanghai200237China Key Laboratory for Advanced Materials and Institute of Fine Chemicals National Engineering Laboratory for Industrial Wastewater TreatmentSchool of Chemistry and Molecular EngineeringEast China University of Science and Technology130 Meilong RoadShanghai200237China Department of Applied Natural Sciences Technische Hochschule LubeckMonkhofer Weg 23923562 LubeckGermany

The existence and risk of emerging organic contaminants(EOCs)have been under consideration and paid much effort to degrade these *** system is one of the most widely used technologies to solve this *** original Fenton system relies on the hydroxyl radicals produced by Fe(Ⅱ)/H_(2)O_(2) to oxidize the organic ***,the application of the Fenton system is limited by its low iron cycling efficiency and the high risks of hydrogen peroxide transportation and *** introduction of external energy(including light and electricity etc.)can effectively promote the Fe(Ⅲ)/Fe(Ⅱ)cycle and the reduction of oxygen to produce hydrogen peroxide in *** review introduces three in-situ Fenton systems,which are electro-Fenton,Photo-Fenton,and chemical *** mechanism,influencing factors,and catalysts of these three in-situ Fenton systems in degrading EOCs are discussed *** review strengthens the understanding of Fenton and in-situ Fenton systems in degradation,offering further insight into the real application of the in-situ Fenton system in the removal of EOCs.

关键词： In-situ H_(2)O_(2)production Fenton Emerging organic contaminants Photocatalysis Electrocatalysis

SPARSE RECOVERY BASED ON THE GENERALIZED ERROR FUNCTION

在线全文

学校读者我要写书评

暂无评论

Journal of Computational Mathematics 2024年第3期42卷 679-704页

作者： Zhiyong zhou Department of Statistics and Data Science and Institute of Digital FinanceHangzhou City UniversityHangzhou 310015China

In this paper,we offer a new sparse recovery strategy based on the generalized error *** introduced penalty function involves both the shape and the scale parameters,making it extremely *** both constrained and unconstrained models,the theoretical analysis results in terms of the null space property,the spherical section property and the restricted invertibility factor are *** practical algorithms via both the iteratively reweighted■_(1)and the difference of convex functions algorithms are *** experiments are carried out to demonstrate the benefits of the suggested approach in a variety of *** practical application in magnetic resonance imaging(MRI)reconstruction is also investigated.

关键词： Sparse recovery Generalized error function Nonconvex regularization Itera-tive reweighted Li Difference of convex functions algorithms

Emergent Geometry of KP Hierarchy

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

Acta Mathematica Sinica,English Series 2024年第1期40卷 3-25页

作者： Jian zhou Department of Mathematical Sciences Tsinghua UniversityBeijng 100084P.R.China

We explain how to construct a quantum deformation of a spectral curve associated to a tau-function of the KP *** construction is applied to Witten-Kontsevich tau-function to give a natural explanation of some earlier ... 详细信息

关键词： KP hierarchy tau-functions spectral curves