检索结果-南通市图书馆

Tracked robot with underactuated tension-driven RRP transformable mechanism:ideas and design

Frontiers of Mechanical Engineering 2024年第1期19卷 85-104页

作者： ran XU Chao LIU school of Mechanical Electronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China key Laboratory of Vehicle Advanced Manufacturing Measuring and Control Technology(Ministry of Education)Beijing Jiaotong UniversityBeijing 100044China

Robots with transformable tracked mechanisms are widely used in complex terrains because of their high adaptability,and many studies on novel locomotion mechanisms have been conducted to make them able to climb higher *** underactuated transformable mechanisms for tracked robots could decrease the number of actuators used while maintaining the flexibility and obstacle-crossing capability of these robots,and increasing their cost ***,the underactuated tracked robots have appreciable research *** this paper,a novel tracked robot with a newly proposed underactuated revolute‒revolute‒prismatic(RRP)transformable mechanism,which is inspired by the sit-up actions of humans,was *** newly proposed tracked robot has only two actuators installed on the track pulleys for moving and does not need extra actuators for ***,it could concentrate the track belt’s tension toward one side,and the unbalanced tension would drive the linkage mechanisms to change its *** this method,the proposed underactuated design could change its external shape to create support points with the terrain and move its center of mass actively at the same time while climbing obstacles or crossing other kinds of terrains,thus greatly improving the climbing capability of the *** geometry and kinematic relationships of the robot and the crossing strategies for three kinds of typical obstacles are *** the basis of such crossing motions,the parameters of links in the robot are designed to make sure the robot has sufficient stability while climbing ***-crossing dynamic simulations were run and analyzed to prove the feasibility of the robot.A prototype was built and *** show that the proposed robot could climb platforms with heights up to 33.3%of the robot’s length or cross gaps with widths up to 43.5%of the robot’s length.

关键词： mechanical design tracked robot underactuated mechanisms RRP mechanism obstacle crossing strategy

来源：

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

single-particle spectroscopies of p-wave and d-wave interacting Bose gases in normal phase

引用

Communications in Theoretical Physics 2024年第5期76卷 140-147页

作者： Zeqing Wang ran Qi Department of Physics Renmin University of ChinaBeijing 100872China

Motivated by experiments with interacting quantum gases across high partial wave resonance,we investigate the thermodynamic properties and single-particle spectra of Bose gases in normal phase for different interaction strengths for both p-and d-wave *** equation of state,contact density,momentum distributions and self-energies of single-particle Green’s functions are obtained in the spirit of ladder diagram *** radio-frequency(RF)spectrum,as an important experimental approach for detecting Feshbach molecules or the interaction effect,is calculated at different temperatures.A reversed temperature dependence on the Bose–Einstein condensation side and Bardeen–Cooper–schrieffer side is identified for both p-and d-wave *** estimate for the signal of RF spectra under typical experimental conditions is also provided.

关键词： quantum gases ultracold atom high partial wave RF spectra

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efficient Unsupervised Image stitching Using Attention Mechanism with Deep Homography Estimation

引用

Computers, Materials & Continua 2024年第4期79卷 1319-1334页

作者： Chunbin Qin Xiaotian ran school of Artificial Intelligence Henan UniversityZhengzhou450000China

Traditional feature-based image stitching techniques often encounter obstacles when dealing with images lackingunique attributes or suffering from quality degradation. The scarcity of annotated datasets in real-life scenesseverely undermines the reliability of supervised learning methods in image stitching. Furthermore, existing deeplearning architectures designed for image stitching are often too bulky to be deployed on mobile and peripheralcomputing devices. To address these challenges, this study proposes a novel unsupervised image stitching methodbased on the YOLOv8 (You Only Look Once version 8) framework that introduces deep homography networksand attentionmechanisms. Themethodology is partitioned into three distinct stages. The initial stage combines theattention mechanism with a pooling pyramid model to enhance the detection and recognition of compact objectsin images, the task of the deep homography networks module is to estimate the global homography of the inputimages consideringmultiple viewpoints. The second stage involves preliminary stitching of the masks generated inthe initial stage and further enhancement through weighted computation to eliminate common stitching *** final stage is characterized by adaptive reconstruction and careful refinement of the initial stitching *** experiments acrossmultiple datasets are executed tometiculously assess the proposed model. Ourmethod’s Peak signal-to-Noise Ratio (PsNR) and structure similarity Index Measure (ssIM) improved by 10.6%and 6%. These experimental results confirm the efficacy and utility of the presented model in this paper.

关键词： Unsupervised image stitching deep homography estimation YOLOv8 attention mechanism

来源：

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

Rapid prediction of damaged ship roll motion responses in beam waves based on stacking algorithm

引用

Journal of Hydrodynamics 2024年第2期36卷 394-405页

作者： Xin-ran Liu Ting-qiu Li Zi-ping Wang school of Naval Architecture Ocean and Energy Power EngineeringWuhan University of TechnologyWuhan430063China

Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics(CFD)and AI *** paper describes a data-driven stacking algorithm for fast prediction of roll motion response amplitudes in beam waves by constructing a hydrodynamics model of a damaged ship based on the dynamic overlapping grid CFD *** general idea is to optimize various parameters varying with four types of classical base models like multi-layer perception,support vector regression,random forest,and hist gradient boosting *** offers several attractive properties in terms of accuracy and efficiency by choosing the standard DTMB 5415 model with double damaged compartments for *** is clearly demonstrated that the predicted response amplitude operator(RAO)in the regular beam waves agrees well with the experimental data available,which verifies the accuracy of the established damaged ship hydrodynamics *** high-quality CFD samples,therefore,implementation of the designed stacking algorithm with its optimal combination can predict the damaged ship roll motion amplitudes effectively and accurately(e.g.,the coefficient of determination 0.9926,the average absolute error 0.0955 and CPU 3s),by comparison of four types of typical base models and their various ***,the established stacking algorithm provides one potential that can break through problems involving the time-consuming and low efficiency for large-scale lengthy CFD simulations.

关键词： ship motion damaged ship computational fluid dynamics(CFD) machine learning stacking algorithm

来源：

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

Particle segregation mechanism of s–D system in a rotating drum

引用

Particuology 2024年第10期93卷 300-308页

作者： Erliang Xiao Wei Zhang Zhipeng Chi ran Li Hui Yang school of Optical-Electricaland Computer Engineering University of Shanghai for Science and Technology Shanghai 200093Chin Collegeof Medical instrumentation hanghai Universty of Medicine&Health ScienceShanghaiChina

Complex segregation occurs in a binary particle system with differing particle sizes and densities,particularly when the larger particles are heavier(s–D system,i.e.,size minus density system).Predicting the segregation pattern driven by multiple mechanisms simultaneously is often *** study explores the segregation mechanisms in a quasi-2D circular drum containing a s–D system,realizing a transition between the s-core and Core-and-band patterns by adjusting the drum rotation *** the transition of the segregation pattern,only the s-core pattern chiefly driven by the percolation mechanism is initially *** the rotation speed increases,the buoyancy mechanism and particle diffusion gradually strengthen,jointly driving the formation of the Core-and-band pattern.A dimensionless strength ratio,λ=H/h,where H and h respectively represent the diffusion and buoyancy strengths at length scales,is introduced to elucidate this *** Core-and-band pattern emerges whenλreached 1.4.

关键词： Particle segregation s-Dsystem segregationmechanisms competition segregation pattern Rotating drum

来源：

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

Recent Progress in Improving Rate Performance of Cellulose-Derived Carbon Materials for sodium-Ion Batteries

引用

Nano-Micro Letters 2024年第8期16卷 102-147页

作者： Fujuan Wang Tianyun Zhang Tian Zhang Tianqi He Fen ran state key Laboratory of Advanced Processing and Recycling of Non‑Ferrous Metals Lanzhou University of TechnologyLanzhou 730050People’s Republic of China school of Materials science and Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China school of Mechanical and Electronical Engineering Lanzhou University of TechnologyLanzhou 730050People’s Republic of China

Cellulose-derived carbon is regarded as one of the most promising candidates for high-performance anode materials in sodium-ion batteries;however,its poor rate performance at higher current density remains a challenge to achieve high power density sodium-ion *** present review comprehensively elucidates the structural characteristics of cellulose-based materials and cellulose-derived carbon materials,explores the limitations in enhancing rate performance arising from ion diffusion and electronic transfer at the level of cellulose-derived carbon materials,and proposes corresponding strategies to improve rate performance targeted at various precursors of cellulose-based *** review also presents an update on recent progress in cellulose-based materials and cellulose-derived carbon materials,with particular focuses on their molecular,crystalline,and aggregation ***,the relationship between storage sodium and rate performance the carbon materials is elucidated through theoretical calculations and characterization ***,future perspectives regarding challenges and opportunities in the research field of cellulose-derived carbon anodes are briefly highlighted.

关键词： Cellulose Hard carbon Anode materials Rate performance sodium-ion batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Understanding the corrosion and bio-corrosion behaviour of Magnesium composites – a critical review

引用

Journal of Magnesium and Alloys 2024年第3期12卷 890-939页

作者： Prithivirajan sekar s.k.Panigrahi Department of Mechanical Engineering Indian Institute of Technology MadrasChennai600036India Applied Magnesium Research Center Center of Excellence in Materials and Manufacturing for Futuristic MobilityIndian Institute of Technology MadrasChennai600036India

Realising the potential of Magnesium(Mg),several globally leading ventures have invested in the Mg industry,but their relatively poor corrosion resistance is a never ending saga till *** corrosion and bio-corrosion behaviour of Mg has gained research attention and still remains a hot topic in the application of automobile,aerospace and biomedical *** intrinsic high electrochemical nature of Mg limits their utilization in diverse *** scenario has prompted the development of Mg composites with an aim to achieve superior corrosion and bio-corrosion *** present review enlightens the influence of grain size(Gs),secondary phase,texture,type of matrix and reinforcement on the corrosion and bio-corrosion behaviour of Mg ***,the corrosion and bio-corrosion behaviour of Mg composites manufactured by primary and secondary processing routes are ***,the comprehensive corrosion and bio-corrosion mechanisms of these Mg composites are ***,the individual role of Gs,texture and corrosive medium on corrosion and bio-corrosion behaviour of Mg composites are clarified and *** challenges encountered,unanswered issues in this field are explained in detail and accordingly the scope for future research is *** review is presented from basic concrete background to advanced corrosion mechanisms with an aim of creating interest among the readers like students,researchers and industry experts from various research ***,the corrosion and bio-corrosion behaviour of Mg composites are critically reviewed for the first time to:(i)contribute to the body of knowledge,(ii)foster research and development,(iii)make breakthrough,and(iv)create life changing innovations in the field of Mg composite corrosion.

关键词： Corrosion Bio corrosion Magnesium alloys Magnesium composites Magnesium implants.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A new route to weak force sensing beyond sQL:squeezed magnons in cavity magnomechanics

引用

science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 166-167页

作者： s.k.Özdemir Department of Engineering science and Mechanics and Materials Research Institute(MRI)The Pennsylvania State UniversityUniversity ParkPA 16802USA

Quantum mechanics imposes limits on measurement accuracy through quantum noise which typically has two components:First is the shot noise originating from vacuum fluctuations and referred to as the imprecision *** is ... 详细信息

关键词： quantum typically vacuum

来源：

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

A Residual Frequency Offset Estimation Method Based on range Migration Fitting

引用

Journal of Beijing Institute of Technology 2024年第2期33卷 103-110页

作者： Liting Zhang Hao Huan ran Tao Xiaogang Tang school of Information and Electronics Beijing Institute of Technology school of Aerospace Information Space Engineering University

Recently, researchers have proposed an emitter localization method based on passive synthetic aperture. However, the unknown residual frequency offset(RFO) between the transmitter and the receiver causes the received Doppler signal to shift, which affects the localization accuracy. To solve this issue, this paper proposes a RFO estimation method based on range migration fitting. Due to the high frequency modulation slope of the linear frequency modulation(LFM)-modulation radar signal, it is not affected by RFO in range compression. Therefore, the azimuth time can be estimated by fitting the peak value position of the pulse compression in range ***, the matched filters are designed under different RFOs. When the zero-Doppler time obtained by the matched filters is consistent with the estimated azimuth time, the given RFO is the real RFO between the transceivers. The simulation results show that the estimation error of azimuth distance does not exceed 20 m when the received signal duration is not less than 3 s, the pulse repetition frequency(PRF) of the transmitter radar signal is not less than 1 k Hz, the range detection is not larger than 1 000 km, and the signal noise ratio(sNR) is not less than –5 d B.

关键词： range migration fitting (RMF) passive localization residual frequency offset (RFO)

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

High performance photodetector based on few-layer MoTe_(2)/Cds_(0.42)se_(0.58) flake heterojunction

引用

Frontiers of physics 2024年第4期19卷 91-101页

作者： ran Ma Qiuhong Tan Peizhi Yang Yingkai Liu Qianjin Wang College of Physics and Electronic Information Yunnan Normal UniversityKunming 650500China Yunnan Provincial key Laboratory for Photoelectric Information Technology Yunnan Normal UniversityKunming 650500China key Laboratory of Advanced Technique&Preparation for Renewable Energy Materials Ministry of EducationYunnan Normal UniversityKunming 650500China

Two-dimensional(2D)transition metal dichalcogenides have been extensively studied due to their fascinating physical properties for constructing high-performance ***,their relatively low responsivities,current on/off ratios and response speeds have hindered their widespread ***,we fabricated a high-performance photodetector based on few-layer MoTe_(2) and Cds_(0.42)se_(0.58) flake *** photodetector exhibited a high responsivity of 7221 A/W,a large current on/off ratio of 1.73×10^(4),a fast response speed of 90/120μs,external quantum efficiency(EQE)reaching up to 1.52×10^(6)%and detectivity(D*)reaching up to 1.67×10^(15) *** excellent performance of the heterojunction photodetector was analyzed by a photocurrent mapping test and first-principle ***,the visible light imaging function was successfully attained on the MoTe_(2)/Cds_(0.42)se_(0.58) photodetectors,indicating that the device had practical imaging application *** findings provide a reference for the design of ultrahighperformance MoTe_(2)-based photodetectors.

关键词： photodetector MoTe_(2) heterojunction visible light imaging first-principles calculations

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：