检索结果-南通市图书馆

Nano Research 2024年第5期17卷 4089-4099页

作者： Taili Du Dianlong Shen Ziyue Xi Hongyong Yu Fangyang Dong Cong Zhao Meixian Zhu Yongjiu Zou Peiting Sun Minyi Xu Dalian Key Laboratory of Marine Micro/Nano Energy and Self-powered Systems Marine Engineering CollegeDalian Maritime UniversityDalian 116026China Collaborative Innovation Research Institute of Autonomous Ship Dalian Maritime UniversityDalian 116026China

An enormous number of wireless sensing nodes(WSNs)are of great significance for the Internet of Things(IoT).It is tremendously prospective to realize the in-situ power supply of WSNs by harvesting unutilized mechanical vibration energy.A harmonic silicone rubber triboelectric nanogenerator(HSR-TENG)is developed focusing on ubiquitous constant working frequency *** unique design of the strip serving as a flexible resonator realizes both soft contact and high and broadband *** significant factors influencing the 1^(st)-order vibration mode of the strip are developed for realizing the harmonic frequency adaptation to external *** surface treatment of the strip improves the output performance of HSR-TENG by 49.1%as well as eliminates the adhesion *** HSR-TENG is able to achieve a voltage output bandwidth of 19 Hz under a vibration strength of 3.0,showing its broadband *** peak power density of 153.9 W/m^(3)is achieved and 12×0.5 W light-emitting diodes(LEDs)are successfully illuminated by the *** can continuously power a temperature sensor by harvesting the actual compressor vibration *** brief,the HSR-TENG provides a promising way for constant frequency vibration energy harvesting,so as to achieve in-situ power supply for the WSNs in the vicinity.

关键词： vibration energy harvesting triboelectric nanogenerator flexible silicone rubber strip harmonic vibration broadband

Trajectory Time Series Compression Algorithm Based on Unsupervised Segmentation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science and Information 2024年第3期12卷 360-378页

作者： Shuang SUN Yan CHEN Zaiji PIAO School of maritime Economics and Management Dalian Maritime UniversityDalian 116026China School of Software Dalian University of Foreign LanguagesDalian 116044China

Aiming at the problem of ignoring the importance of starting point features of trajecory segmentation in existing trajectory compression algorithms,a study was conducted on the preprocessing process of trajectory time ***,an algorithm improvement was proposed based on the segmentation algorithm GRASP-UTS(Greedy Randomized Adaptive Search Procedure for Unsupervised Trajectory Segmentation).On the basis of considering trajectory coverage,this algorithm designs an adaptive parameter adjustment to segment long-term trajectory data reasonably and the identification of an optimal starting point for *** the compression efficiency of typical offline and online algorithms,such as the Douglas-Peucker algorithm,the Sliding Window algorithm and its enhancements,was compared before and after *** experimental findings highlight that the Adaptive Parameters GRASP-UTS segmentation approach leads to higher fitting precision in trajectory time series compression and improved algorithm efficiency ***,the compression performance of the Improved Sliding Window algorithm post-segmentation showcases its suitability for trajectories of varying scales,providing reasonable compression accuracy.

关键词： trajectory time series unsupervised segmentation trajectory compression greedy ran-domized adaptive search

维普期刊数据库

Data-driven electrical resistance tomography for robotic large-area tactile sensing

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第9期67卷 336-337页

作者： Wendong ZHENG Huaping LIU Xiaofeng LIU Fuchun SUN School of Electrical Engineering and Automation Tianjin University of Technology department of Computer Science and Technology Tsinghua University Key Laboratory of maritime Intelligent Cyberspace Technology (Hohai University) Ministry of Education

Tactile sensing plays a crucial role in enabling robots to safely interact with objects in dynamic environments [1].Given that potential physical contact can occur at any location during robot interaction, there is a ... 详细信息

关键词： Robot applications

Experimental study on the dynamic response of a 3-D wedge under asymmetric impact

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2024年第2期36卷 263-274页

作者： Saeed Hosseinzadeh Kristjan Tabri maritime Engineering Research Group School of EngineeringUniversity of SouthamptonSouthamptonUK department of Civil Engineering and Architecture Tallinn University of TechnologyTallinnEstonia Marine Technology Competence Center Tallinn University of TechnologyKuressaareEstonia

Water entry problems represent complex multiphase flows involving air,water,and structure interaction,occurring rapidly in rough seas,and potentially effecting structural integrity of floating *** paper experimentally investigates asymmetric slamming loads acting on a 3-D elastic wedge *** specimen,featuring two different bottom plates(stiffened and unstiffened),each 4 mm thick,aims to assess the effect of structural stiffness on dynamic *** experiments are conducted at different drop heights of 25 cm and 50 cm and varying heel angles from 5°to 25°.The paper describes the experimental conditions,including wedge geometry,material properties,and the test *** study explores the influence of heel angle on impact acceleration,revealing an increase in peak acceleration with a higher inclination angle,particularly in the vertical ***,the hydrodynamic pressure resulting from asymmetric slamming is *** pressure results analyzed and compared at different locations along the length of the *** experimental findings indicate that,despite the leeward side(stiffened)experiencing a smaller hydrodynamic load,the heel angle significantly affects pressure results on the windward side(unstiffened),leading to a more pronounced dynamic *** time history of pressure results emphasizes the effect of elastic vibrations,particularly noticeable on the unstiffened bottom *** study contributes to a deeper understanding of asymmetric slamming on aluminum structures,facilitating the enhancement of mathematical models and the validation of numerical simulations.

关键词： Flexible fluid structure interactions(FFSI) experimental study asymmetric impact hydrodynamic pressure slamming loads

Exploring the electromagnetic shielding behavior of lanthanum doped calcium nanoferrites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第11期42卷 2128-2136页

作者： E.Ahilandeswari K.Sakthipandi R.Rajesh Kanna G.Rajkumar B.Ganesh Babu S.Arunmetha Aslam Hossain P.Sakthivel V.Rajendran M.Srinidhi Raghavan department of Physics SRM TRP Engineering College department of Electronics and Communication Engineering M. Kumarasamy College of Engineering department of Physics Easwari Engineering College department of Mechanical Engineering SRM TRP Engineering College Centre for Advanced Energy studies Department of Electronics and Communication EngineeringKoneru Lakshmaiah Education Foundation Smart Materials Research Institute Southern Federal University Centre for Materials Science Department of PhysicsScience and HumanitiesFaculty of EngineeringKarpagam Academy of Higher Education Centre for Nanotechnology Academy of Maritime Education and Training (Deemed to be University) department of Chemistry and Centre for Nano-Materials and Displays B.M.S. College of Engineering

The present study focuses on the synthesis and characterization of lanthanum(La3+)-doped calcium nanoferrites(CaLaxFe2-xO4:x=0.025,0.050,0.075 and 0.100) using the sonochemical *** techniques were employed to analyze the effect of La3+infusion,Raman spectroscopy confirms the presence of active A1g,T2gand Egmodes in the CaLaxFe2-xO4nanoferrite,indicating the formation of an active ferrite *** introduction of La3+doping results in a significant increase in the band gap energy,rendering the nanoferrites insulating（3.23-3,57 eV）.At higher frequencies,the impedance studies reveal minimal losses and better AC conductivity,pointing to improved dielectric *** higher frequencies,the Q-factor of La-doped calcium nanoferrites shows lower electromagnetic *** M-H curve exhibits ferromagnetic behavior,with La3+-doped calcium nano ferrites displaying a saturation magnetization ranging from 12.72 to 18.10 emu/*** incorporation of La3+also induces enhanced electrical polarization,leading to notable dielectric loss and increased absorption of electromagnetic ***,these CaLaxFe2-xO4nanoferrites demonstrate potential as effective microwave absorbers across a wide frequency range,with significant shielding absorption observed at 8.8-9.1 GHz.

关键词： Dielectric Magnetism Microwave absorption Nanoferrites Rare earths Structural properties

Integer multiple quantum image scaling based on NEQR and bicubic interpolation

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第4期33卷 259-273页

作者：蔡硕周日贵罗佳陈思哲 College of Information Engineering Shanghai Maritime UniversityShanghai 201306China Research Center of Intelligent Information Processing and Quantum Intelligent Computing Shanghai 201306China College of Merchant Marine Shanghai Maritime UniversityShanghai 201306China School of Mathematics and Computational Science Shangrao Normal UniversityShangrao 334001China

As a branch of quantum image processing,quantum image scaling has been widely ***,most of the existing quantum image scaling algorithms are based on nearest-neighbor interpolation and bilinear interpolation,the quantum version of bicubic interpolation has not yet been *** this work,we present the first quantum image scaling scheme for bicubic interpolation based on the novel enhanced quantum representation(NEQR).Our scheme can realize synchronous enlargement and reduction of the image with the size of 2^(n)×2^(n) by integral ***,the image is represented by NEQR and the original image coordinates are obtained through multiple CNOT ***,16 neighborhood pixels are obtained by quantum operation circuits,and the corresponding weights of these pixels are calculated by quantum arithmetic ***,a quantum matrix operation,instead of a classical convolution operation,is used to realize the sum of convolution of these *** simulation experiments and complexity analysis,we demonstrate that our scheme achieves exponential speedup over the classical bicubic interpolation algorithm,and has better effect than the quantum version of bilinear interpolation.

关键词： quantum image processing image scaling bicubic interpolation quantum circuit

维普期刊数据库

First experience in laparoscopic surgery in low and middle income countries: A systematic review

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第2期16卷 546-553页

作者： Rebekka Troller Jasmine Bawa Olivia Baker James Ashcroft department of Surgery Medway Maritime HospitalGillingham ME75NYKentUnited Kingdom department of Surgery University Hospital CambridgeCambridge CB20QQUnited Kingdom

BACKGROUND Laparoscopic surgery has reduced morbidity and mortality rates,shorter post-operative recovery periods and lower complication rates than open *** is routine practice in high-income countries and is becoming increasingly common in countries with limited ***,introducing laparoscopic surgery in low-and-middle-income countries(LMIC)can be expensive and requires resour-ces,equipment,and *** To report the challenges and benefits of introducing laparoscopic surgery in LMIC as well as to identify solutions to these challenges for countries with limited finances and *** MEDLINE,EMBASE and Cochrane databases were searched for studies reporting first experience in laparoscopic surgery in *** studies were published between 1996 and 2022 with full text available in *** criteria were studies considering only open surgery,ear,nose,and throat,endoscopy,arthro-scopy,hysteroscopy,cystoscopy,transplant,or bariatric *** Ten studies out of 3409 screened papers,from eight LMIC were eligible for inclusion in the final analysis,totaling 2497 *** reported challenges were related to costs of equipment and training programmes,equipment pro-blems such as faulty equipment,and access to surgical ***-related challenges were reliance on foreign trainers and lack of locally trained surgeons and theatre *** benefits of introducing laparoscopic surgery were economic and clinical,including a reduction in hospital stay,complications,and morbidi-ty/*** introduction of laparoscopic surgery also provided training opportunities for junior *** Despite financial and technical challenges,many studies emphasise the overall benefit of introducing laparoscopic surgery in LMICs such as reduced hospital stay and the related lower cost for *** many of the clinical centres in LMICs have proposed practical solutions to the challenges reported,more support is critical

关键词： Laparoscopic surgery Low and middle income country First experience Training in laparoscopic surgery

Low-rank spectral estimation algorithm of learning Markov model

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Mathematics in China 2024年第3期19卷 137-155页

作者： Yongye ZHAO Shujun BI department of Basic Courses Guangzhou Maritime UniversityGuangzhou 510725China department of Mathematics South China University of TechnologyGuangzhou 510640China

This paper proposes a low-rank spectral estimation algorithm of learning Markov ***,an approximate projection algorithm for the rank-constrained frequency matrix set is proposed,and thereafter its local Lipschitzian error bound ***,we propose a low-rank spectral estimation algorithm for estimating the state transition frequency matrix and the probability matrix of Markov model by applying the approximate projection algorithm to correct the maximum likelihood estimation of the frequency matrix,and prove that there is only a multiplying constant difference in estimation errors between the low-rank spectral estimation and the maximum likelihood estimation under appropriate ***,numerical comparisons with the prevailing maximum likelihood estimation,spectral estimation,and rank-constrained maxi-mum likelihood estimation show that the low-rank spectral estimation algorithm is effective.

关键词： Markov model low-rank spectral estimation error bound approximate projection

Tribological evaluation of thermoplastic polyurethane-based bearing materials under water lubrication:Effect of load,sliding speed,and temperature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第8期12卷 1801-1815页

作者： Shaoli JIANG Janet SSWONG Debashis PUHAN Tian YUAN Xiuqin BAI Chengqing YUAN State Key Laboratory of maritime Technology and Safety Wuhan University of TechnologyWuhan 430063China department of Mechanical Engineering Imperial College LondonLondon SW72AZUK Yusuf Hamied department of Chemistry University of CambridgeLensfield RoadCambridge CB21EWUK

Polymers are widely used in bearing *** the case of water-lubricated stern tube bearings,thermoplastic polyurethane(TPU)-based composites are used due to their excellent wear resistance,corrosion resistance,and tunable mechanical *** tribological performance,however,depends on operating *** this work,TPU was blended with carbon fiber,graphene platelet,and ultra-high molecular weight polyethylene(UHMWPE).Friction tests of TPU based-composites against copper countersurface were carried out in water to mimic the actual operating conditions of the *** of the resulting contacts were in the boundary lubrication regime,in which friction was attributed to both contact mechanics of asperities as well as water *** results show that the viscoelasticity of TPU has a considerable impact on its tribological *** lubrication at 50°C promotes the softening of polymer surface material during sliding,resulting in higher fluctuation in the coefficient of friction and wear *** is attributed to the reduced thermomechanical *** addition,Schallamach waviness is observed on worn *** tribological properties of TPU are significantly improved by the inclusion of carbon fiber,graphene platelet,and *** formation of graphene transfer-layers and UHMWPE transfer film reduces friction and wear loss,while the inclusion of carbon fiber enhances wear resistance due to improved mechanical properties and load bearing capacity.

关键词： friction thermoplastic polyurethane(TPU) water-lubricated bearings graphene platelet carbon fibers ultra-high molecular weight polyethylene(UHMWPE)

Energy flexibility and resilience analysis of demand-side energy efficiency measures within existing residential houses during cold wave event

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Building Simulation 2024年第7期17卷 1043-1063页

作者： Xiaoyi Zhang Fu Xiao Yanxue Li Yi Ran Weijun Gao Innovation Institute for Sustainable maritime Architecture Research and Technology Qingdao University of TechnologyQingdaoChina department of Building Environment and Energy Engineering The Hong Kong Polytechnic UniversityHong KongChina Faculty of Environmental Engineering The Universityof KitakyushuKitakyushuJapan

Using the behind-meter data,this study applied a comparison and optimization-based framework to evaluate the energy flexibility and resilience of distributed energy resources within existing houses during cold wave *** analysis demonstrates the effectiveness of high envelope insulation level in improving energy resilience,identifies impacts of distributed energy resources on variations of household electricity ***,a 14.6%reduction in the median value of the normalized load of building group with low U-values,implementations of cogeneration system effectively suppressed variations of electricity *** energy performances of on-site generators are evaluated based on high resolution data,energy flexibility of domestic hot water and thermostatically controlled loads were investigated through built demand response *** reveal that electrifying hot water demand offers additional power flexibility,the integration of fuel cell cogeneration system has proven to be an efficient energy resource,enabling on-site generation of both electricity and hot water,substantially reducing grid *** extreme cold event resulted in significant spikes in space heating power *** optimization results demonstrate that reducing the indoor setpoint temperature effectively decreases daily power consumption by approximately 5.0%per degree *** findings help acquire better understanding of interconnections between energy efficiency and resilience of residential energy-efficient measures.

关键词： system modeling energy efficiency energy resilience cold wave thermal comfort