检索结果-南通市图书馆

Near-zero stiffness accelerometer with buckling of tunable electrothermal microbeams

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第2期10卷 67-81页

作者： Hussein Hussein Chen Wang Rui Amendoeira Esteves michael Kraft Hossein Fariborzi Department of Mechanical Engineering MSFEAAmerican University of BeirutBeirut11072020Lebanon King Abdullah University of Science and Technology Thuwal23955-6900Saudi Arabia ESAT-MNS University of Leuven3001LeuvenBelgium

Pre-shaped microbeams,curved or inclined,are widely used in MEMS for their interesting stiffness *** mechanisms allow a wide range of positive and negative stiffness tuning in their direction of motion.A mechanism of pre-shaped beams with opposite curvature,connected in a parallel configuration,can be electrothermally tuned to reach a near-zero or negative stiffness behavior at the as-fabricated *** simple structure helps incorporate the tunable spring mechanism in different designs for accelerometers,even with different transduction *** sensitivity of the accelerometer can be considerably increased or tuned for different applications by electrothermally changing the stiffness of the spring *** inclined beams are implemented in a capacitive micromachined *** measurements on fabricated prototypes showed more than 55 times gain in sensitivity compared to their initial *** experiments showed promising results in enhancing the resolution of acceleration sensing and the potential to reach unprecedent performance in micromachined accelerometers.

关键词： properties. mechanism. stiffness

Anisotropic time-dependent behaviors of shale under direct shearing and associated empirical creep models

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 Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1262-1279页

作者： Yachen Xie michael Z.Hou Hejuan Liu Cunbao Li Shenzhen Key Laboratory of Deep Engineering Sciences and Green Energy Shenzhen UniversityShenzhen518060China Institute of Subsurface Energy Systems Clausthal University of TechnologyClausthal-Zellerfeld38678Germany State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

Understanding the anisotropic creep behaviors of shale under direct shearing is a challenging *** this context,we conducted shear-creep and steady-creep tests on shale with five bedding orientations (i.e.0°,30°,45°,60°,and 90°),under multiple levels of direct shearing for the first *** results show that the anisotropic creep of shale exhibits a significant stress-dependent *** a low shear stress,the creep compliance of shale increases linearly with the logarithm of time at all bedding orientations,and the increase depends on the bedding orientation and creep *** high shear stress conditions,the creep compliance of shale is minimal when the bedding orientation is 0°,and the steady-creep rate of shale increases significantly with increasing bedding orientations of 30°,45°,60°,and 90°.The stress-strain values corresponding to the inception of the accelerated creep stage show an increasing and then decreasing trend with the bedding orientation.A semilogarithmic model that could reflect the stress dependence of the steady-creep rate while considering the hardening and damage process is *** model minimizes the deviation of the calculated steady-state creep rate from the observed value and reveals the behavior of the bedding orientation's influence on the steady-creep *** applicability of the five classical empirical creep models is quantitatively *** shows that the logarithmic model can well explain the experimental creep strain and creep rate,and it can accurately predict long-term shear creep *** on an improved logarithmic model,the variations in creep parameters with shear stress and bedding orientations are *** abovementioned findings,a mathematical method for constructing an anisotropic shear creep model of shale is proposed,which can characterize the nonlinear dependence of the anisotropic shear creep behavior of shale on the bedding orientation.

关键词： Rock anisotropy Direct shear creep Creep compliance Steady-creep rate Empirical model Creep constitutive model

A comparative study on design standards of screw conveyors in China,Germany,and the USA–Part II:Discrete element method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第9期92卷 113-125页

作者： Yuan Tan michael Rackl Weijie Yang Johannes Fottner Wenjun Meng Stephan Kessler Technical University of Munich Chair for Materials HandlingMaterial FlowLogisticsGarchingGermany Ibracon–Ingenieurbüro Dr.-Ing.Rackl ZornedingGermany School of Mechanical Engineering Taiyuan University of Science and TechnologyTaiyuanChina

This part of the study aims to evaluate the advantages and disadvantages of technical standards of screw conveyors in China,Germany,and the USA for industrial *** source or determination method of empirical coefficients as well as the theoretical foundation of dimensioning-relevant diagrams in these standards is not explicitly documented in the ***,instead of less efficient on-site tests,the numerical simulation by discrete element method is *** on the geometrical and operational designs determined in three standards for horizontal,slightly inclined,and vertical conveyance of three representative bulk solids(barley,lignite,and sand),the potential influencing factors are *** constant particle and contact parameters,the potential deviations caused by particle models are ***,the accuracy of power consumption calculation of each standard and the divergence between accessible and required mass flows is comprehensively assessed based on the analysis of simulated *** main conclusions are drawn:(1)Particle fall back is barely considered by all three standards and leads to overestimated mass throughput;(2)The decrease in mass throughput caused by an increasing degree of filling can be compensated by slowing down the rotational speed.

关键词： Discrete element method Design standard Screw conveyor Screw auger Bulk solid

Importance-aware 3D volume visualization for medical content-based image retrieval-a preliminary study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

虚拟现实与智能硬件（中英文） 2024年第1期6卷 71-81页

作者： Mingjian LI Younhyun JUNG michael FULHAM Jinman KIM School of Computer Science The University of SydneySydneyNSW 2006Australia School of Computing Gachon UniversitySeongnam 13120South Korea Department of Molecular Imaging Royal Prince Alfred HospitalSydneyNSW 2050Australia

Background A medical content-based image retrieval(CBIR)system is designed to retrieve images from large imaging repositories that are visually similar to a user′s query *** is widely used in evidence-based diagnosis,teaching,and *** the retrieval accuracy has largely improved,there has been limited development toward visualizing important image features that indicate the similarity of retrieved *** the prevalence of 3D volumetric data in medical imaging such as computed tomography(CT),current CBIR systems still rely on 2D cross-sectional views for the visualization of retrieved *** 2D visualization requires users to browse through the image stacks to confirm the similarity of the retrieved images and often involves mental reconstruction of 3D information,including the size,shape,and spatial relations of multiple *** process is time-consuming and reliant on users'*** In this study,we proposed an importance-aware 3D volume visualization *** rendering parameters were automatically optimized to maximize the visibility of important structures that were detected and prioritized in the retrieval *** then integrated the proposed visualization into a CBIR system,thereby complementing the 2D cross-sectional views for relevance feedback and further *** Our preliminary results demonstrate that 3D visualization can provide additional information using multimodal positron emission tomography and computed tomography(PETCT)images of a non-small cell lung cancer dataset.

关键词： Volume visualization DVR Medical CBIR Retrieval Medical images

Navigating the Challenges of Emerging Contaminants to Protect Human and Ecological Health

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

Engineering 2024年第6期37卷 1-2页

作者： Jiuhui Qu michael R.Hoffmann Gang Yu School of Environment Tsinghua UniversityBeijing 100084China Linde-Robinson Laboratories California Institute of TechnologyPasadenaCA 91125USA Advanced Interdisciplinary Institute of Environmental and Ecology Beijing Normal UniversityZhuhai 519000China

Emerging contaminants are defined as chemicals that are not currently(or have only recently been)regulated and about which there are concerns regarding their impact on human or ecological *** contaminants are widely detected in air,water,soil,sediment,and biotic *** is against this backdrop of urgency that we have curated this special issue titled“Emerging Contaminants Control:Science and Technology,”with the goal of uniting the latest scientific insights and pioneering strategies to address this global *** special issue embarks on a comprehensive examination of the emerging contaminants dilemma,covering aspects such as risk assessment,remediation technologies,environmental surveying,and the broader implications for *** a collection of articles,we probe deep into the core of this issue,showcasing studies that range from appraising environmental risks to forging new methods for treatment and scrutinizing the occurrence of contaminants across different environmental settings.

关键词： Ecological surveying environmental

Use of an immunocapture device to detect cytokine release in discrete brain regions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第4期19卷 703-704页

作者： Matthew G.Frank michael V.Baratta Department of Integrative Physiology University of Colorado BoulderBoulderCOUSA(Frank MG)Department of Psychology and NeuroscienceUniversity of Colorado BoulderBoulderCOUSA(Baratta MV)

Production of proinflammatory cytokines in the central nervous system is a key process in the neuroinflammatory response to trauma,infection,and neurodegenerative diseases(Kumar,2019).These intercellular signaling molecules play multiple roles in the immune response in the central nervous system including the orchestration of the sickness response to innate immune perturbations in the brain(Dantzer et al.,2008).

关键词： system release innate

From seawater to hydrogen via direct photocatalytic vapor splitting: A review on device design and system integration

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

Frontiers in Energy 2024年第3期18卷 291-307页

作者： Hongxia LI Khaja WAHAB AHMED Mohamed A.ABDELSALAM michael FOWLER Xiao-Yu WU Technology Innovation Institute Masdar CityAbu Dhabi 9639United Arab Emirates Department of Chemical Engineering University of WaterlooWaterlooON N2L 3G1Canada Department of Mechanical and Nuclear Engineering Khalifa University of Science and TechnologyAbu Dhabi 127788United Arab Emirates Department of Mechanical and Mechatronics Engineering University of WaterlooWaterlooON N2L 3G1Canada

Solar-driven hydrogen production from seawater attracts great interest for its emerging role in decarbonizing global energy consumption. Given the complexity of natural seawater content, photocatalytic vapor splitting offers a low-cost and safe solution, but with a very low solar-to-hydrogen conversion efficiency. With a focus on cutting-edge photothermal–photocatalytic device design and system integration, the recent research advances on vapor splitting from seawater, as well as industrial implementations in the past decades were reviewed. In addition, the design strategies of the key processes were reviewed, including vapor temperature and pressure control during solar thermal vapor generation from seawater, capillary-fed vaporization with salt repellent, and direct photocatalytic vapor splitting for hydrogen production. Moreover, the existing laboratory-scale and industrial-scale systems, and the integration principles and remaining challenges in the future seawater-to-hydrogen technology were discussed.

关键词： seawater hydrogen photocatalytic vapor splitting solar-driven

Sleep-based neuronal oscillations as a physiological biomarker for Alzheimer's disease:is night time the right time?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第7期19卷 1417-1418页

作者： Jonathan Witton Erica S.Brady michael T.Craig Department of Clinical and Biomedical Sciences Faculty of Health and Life SciencesUniversity of ExeterExeterEnglandUK Gladstone Institute for Neurological Disease San FranciscoCAUSA School of Psychology and Neuroscience College of MedicalVeterinary and Life SciencesUniversity of GlasgowGlasgowScotlandUK

Dementia is a devastating syndrome characterized by memory problems,confusion,and behavior changes that prevent people from performing everyday *** is the leading cause of dependency and disability amongst older people,resulting in a global economic cost of ~$1.3 *** 58 million people are currently afflicted by dementia worldwide,with Alzheimer s disease(AD) causing most(60-70%) of these cases.

关键词： Alzheimer everyday performing

Application of a simplified ADM1 for full-scale anaerobic co-digestion of cattle slurry and grass silage:assessment of input variability

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

Frontiers of Environmental Science & Engineering 2024年第4期18卷 125-139页

作者： Sofia Tisocco Sören Weinrich Gary Lyons michael Wills Xinmin Zhan Paul Crosson Civil Engineering College of Science and EngineeringUniversity of GalwayGalwayH91 TK33Ireland Teagasc Animal and Bioscience Research Department Animal and Grassland Research and Innovation CentreDunsanyC15 PW93Ireland Biochemical Conversion Department Deutsches Biomasseforschungszentrum gemeinnützige GmbHLeipzig 04347Germany Faculty of Energy·Building Services·Environmental Engineering Münster University of Applied SciencesSteinfurt 48565Germany Agri-Food and Biosciences Institute HillsboroughBT266DRUK Ryan Institute University of GalwayGalwayH91 TK33Ireland MaREI Research Centre for Energy Climate and MarineRyan InstituteUniversity of GalwayGalwayH91 TK33Ireland

Mathematical modeling of anaerobic digestion is a powerful tool to predict gas yields and optimize the *** Anaerobic Digestion Model No.1(ADM1)is a widely implemented model for this ***,modeling full-scale biogas plants is challenging due to the extensive substrate and parameter characterization *** study describes the modification of the ADM1 through a simplification of individual process phases,characteristic components and required ***,the ability of the simplified model to simulate the co-digestion of grass silage and cattle slurry was evaluated using data from a full-scale biogas *** impacts of substrate composition(crude carbohydrate,protein and lipid concentration)and variability of carbohydrate degradability on simulation results were assessed to identify the most influential *** indicated that the simplified version was able to depict biogas and biomethane production with average model efficiencies,according to the Nash-Sutcliffe efficiency(NSE)coefficient,of 0.70 and 0.67,respectively,and was comparable to the original ADM1(average model efficiencies of 0.71 and 0.63,respectively).The variability of crude carbohydrate,protein and lipid concentration did not significantly impact biogas and biomethane output for the data sets *** contrast,carbohydrate degradability seemed to explain much more of the variability in the biogas and methane ***,the application of simplified models provides a reliable basis for the process simulation and optimization of full-scale agricultural biogas plants.

关键词： ADM1 Agricultural feedstocks Biogas technology Input variability Parameter estimation