检索结果-南通市图书馆

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1033-1050页

作者： t.i.tOLUWALOJU C.K.tHEiN D.HALiM Department of Mechanical Materials and Manufacturing EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100Zhejiang ProvinceChina Nottingham Ningbo China Beacons of Excellence Research and innovation institute University of Nottingham Ningbo ChinaNingbo 315048Zhejiang ProvinceChina

the levered-dual response(LEDAR)Coulomb-damped system attains near resonant vibration isolation by differential preloads/offsets in linear *** takes the advantages of both the preloads/offsets in linear springs and the guiderail friction for realizing different levels of vibration *** isolation capacities are investigated on the strategies with both the horizontal and vertical guiderails,with the horizontal rail only,and without *** compressive preloads generally result in the consumption of most of the initial excitation energy so as to overcome the potential *** isolation onsets at the frequency ratio of 1∓0.095 on the left-hand side(LHS)and the right-hand side(RHS)of the lever are relative to the load plate *** observed near resonant isolation thus makes the LEDAR system a candidate for the isolation of the mechanical systems about resonance while opening a path for simultaneous harvesterisolation functions and passive functions at extreme frequencies.

关键词： lever ratio Coulomb damping preload tension/compression isolation band/depth offset potential

维普期刊数据库

Energy exchange between charged relativistic fluids in f(t) gravity

在线全文

学校读者我要写书评

暂无评论

Communications in theoretical Physics 2024年第10期76卷 108-120页

作者： Z Yousaf U A Khokhar Nasser Bin turki t Suzuki Department of Mathematics University of the Punjab Quaid-i-Azam Campus Department of Mathematics College of Science King Saud University Department of Regional Management Faculty of Management Fukushima College

this study focuses on the effects of a polytropic fluid on a charged gravitational source within f(t) gravity, where t is the torsion scalar. We investigate how the electromagnetic field affects the flow of energy in spherically symmetric and static celestial objects that contain relativistic fluids. By using the gravitational decoupling technique, we analyze the effects of polytropic fluid on the dynamics of the gravitational source, accompanied by the matching of the interior geometry with an exterior at the hypersurface Σ. Finally, with the help of the tolman ⅡV solution, we observe the conduct of energy conditions with the existence of charge using f(t)field equations and got the intended outcomes.

关键词： anisotropy complexity energy exchange hydrodynamics self-gravitating systems

Development of endemicity and conservation importance indices for tropical forests and the floral diversity assessment of *** in Benguet,Philippines

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 Mountain Science 2024年第3期21卷 786-804页

作者： Johndale Rein t.BULLONG Jim P.SiLVERiO Joanna i.ALAFAG Maricel A.GURON Jones t.NAPALDEt Department of Environmental Science Benguet State UniversityLa Trinidad 2601Philippines Department of Biology Benguet State UniversityLa Trinidad 2601Philippines

the scientific community faces the challenge of measuring progress toward biodiversity targets and indices have been traditionally ***,recent inventories in secondary tropical mountain forests using traditional biodiversity indices have yielded results that are indistinct with primary *** shows the need to develop complementary indices that goes beyond species count but integrates the distribution and conservation status of the *** study developed endemicity and conservation importance index for tropical forest that incorporated the distribution and conservation status of the *** indices were applied to ***,a remnant primary mossy forest in Buguias,Benguet,Philippines,that resulted to endemicity index of 81.07 and conservation importance index of *** these with secondary forest sites with comparable Shannon-Wiener,Simpson,Evenness and Margalef’s indices,our endemicity and conservation indices clearly differentiates primary forest(our study site)with higher values from secondary forests with much lower ***,we are proposing these indices for a direct but scientifically-informed identification of specific sites for conservation and protection in tropical ***,our study documented a total of 168 vascular plant species(79 endemic and 12 locally threatened species)in *** are of tropical elements for both generic and species levels with some temperate elements that could be attributed to the site's high elevation and semi-temperate *** are important baseline information for conservation plans and monitoring of tropical mossy forests.

关键词： Endemicity index Conservation importance index Cordillera Central Range Floristic element Jaccard index of Similarity

维普期刊数据库

Design,simulation,and testing of a tunable MEMS multi-threshold inertial switch

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第2期10卷 37-46页

作者： Qiu Xu Rodrigo t.Rocha Yousef Algoos Eric Feron Mohammad i.Younis Faculty of Electronic information Engineering Huaiyin Institute of TechnologyHuai’an223003PR China Computer Electrical and Mathematical Science and Engineering DivisionKing Abdullah University of Science and TechnologyThuwal23955-6900Saudi Arabia Piezoelectric Microsystem technologies Silicon Austria LabsVillach9524Austria Physical Sciences and Engineering Division King Abdullah University of Science and TechnologyThuwal23955Saudi Arabia Mechanical Engineering Department State University of New YorkBinghamtonNY13902USA

this paper presents a tunable multi-threshold micro-electromechanical inertial switch with adjustable threshold *** demonstrated device combines the advantages of accelerometers in providing quantitative acceleration measurements and g-threshold switches in saving power when in the inactive state upon experiencing acceleration below the *** designed proof-of-concept device with two thresholds consists of a cantilever microbeam and two stationary electrodes placed at different positions in the sensing *** adjustable threshold capability and the effect of the shock duration on the threshold acceleration are analytically investigated using a nonlinear beam *** are shown for the relationships among the applied bias voltage,the duration of shock impact,and the tunable *** fabricated prototypes are tested using a shock-table *** analytical results agree with the experimental *** designed device concept is very promising for the classification of the shock and impact loads in transportation and healthcare applications.

关键词： tunable acceleration testing

Evaluation of periglacial landforms and formation of soil properties on the Mount Honaz,SW türkiye

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 Mountain Science 2024年第9期21卷 3047-3067页

作者： SERiN Soner UNCU Levent DEDE Volkan tÜRKEŞMurat institute of Social Sciences İstanbul Universityİstanbul 34119Türkiye Department of Geography BilecikŞeyh Edebali UniversityBilecik 11234Türkiye Department of Geography Ardahan UniversityArdahan 75002Türkiye Center for Climate Change and Policy Studies Boğaziçi Universityİstanbul 34342Türkiye

the main aim of this study is to explain periglacial processes on the summits of Mount Honaz(2571 m a.s.l.),define periglacial landforms,and determine the relationships between morphometric features and topographic *** circles,stony earth circles,non sorted steps,and non sorted stripes were identified on the summits of Mount ***'s correlation coefficient(r)and linear regression analyses were performed by taking metric measurements from 125 periglacial landforms to describe their morphometric features(length,width,height)of periglacial landforms and explain the relationships between them and topographic factors(elevation,slope).to explain the relationships between periglacial landforms and soil properties,soil samples from 11 periglacial landforms were taken and *** landforms,which continue to develop on the summits of Mount Honaz today,have been evaluated with present climate *** of soil samples indicates a notable impact of parent material on the genesis of periglacial *** high ratio of organic matter in mud circle and non sorted step landforms and the high lime ratio in stony earth circle landforms prove a strong relationship between the formation mechanisms of landforms and the soil ***,it is consistent with the findings obtained from the analysis that severe periglacial processes and washing and scavenging events are experienced more on the northern slopes.

关键词： Periglacial processes and geomorphology Soil analysis Morphometric analysis Mount Honaz türkiye

维普期刊数据库

Late Ordovician Mass Extinction: Earth, fire and ice

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第1期11卷 51-65页

作者： David A.t.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

the Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. two phases have been identified near the start of the Hirnantian period and in the middle. it was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. these symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

Preparation of microparticles and nanoparticles using membrane-assisted dispersion,micromixing,and evaporation processes

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第1期84卷 30-44页

作者： Goran t.Vladisavljevic Chemical Engineering Department Loughborough UniversityLoughboroughLeicestershire LE113TUUnited Kingdom

Synthetic microporous membranes are increasingly used for energy-efficient and controlled production of micro-and nanoparticles and micro-and nanoemulsions with tuneable morphology and physico-chemical properties through various micromixing,emulsification,and evaporation *** emul-sification processes,the membrane pores are used for dispersed phase injection and size-controlled generation of droplets and droplet-templated *** micromixing processes,membrane is utilised as a micromixer for mixing two miscible liquids,usually solvent and antisolvent-rich solutions,which leads to the creation of supersaturation and subsequent nanoprecipitation or *** mem-brane evaporation processes,membrane is used to prevent phase dispersion while allowing efficient molecular diffusion of solvent and/or antisolvent vapour through gas-filled *** dispersion processes can be operated continuously by decoupling shear stress on the membrane surface from cross flow using tube insets,flow pulsations,swirling flow,membrane oscillations or membrane *** generation and solidification can be performed continuously in a single pass by connecting membrane module with a downstream *** dispersion processes can be used for pro-duction of nanoparticles such as nanovesicles(liposomes,micelles,ethosomes,and niosomes),nanogels,polymeric,lipid and metallic nanoparticles,and *** main advantages of membrane-assisted particle generation are in low energy consumption,controlled geometry and hydrodynamic conditions at the microscale level,flexible throughput due to modular and scalable design of membrane devices,and a wide choice of available microporous membranes with various wall porosities,wetta-bilities,pore sizes,and pore morphologies to suit different applications.

关键词： Nanoparticles Microparticles Nanoemulsions Microemulsions Microporous membrane Crystallisation Flash nanoprecipitation Emulsification Zero liquid discharge

Beta-lactam antibiotic resistance among Escherichia coli isolates from patients with urinary tract infections in Vietnam:A systematic review and meta-analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of tropical Medicine 2024年第6期17卷 243-255,I0001-I0003页

作者： Dat t Nguyen Princess Margaret Cancer Centre University Health NetworkTorontoOntarioCanada

Objective:to investigate the evolving patterns of antimicrobial resistance against beta-lactam antibiotics in Escherichia coli isolates from urinary tract infection patients in Vietnam,covering the period from 2005 to ***:29 Descriptive studies published between 2010 and 2022 in English and Vietnamese were included in the *** on resistance rates to beta-lactam antibiotics,including cephalosporins and carbapenems,were extracted and *** pooled resistance rates were calculated using random-effects *** trends in resistance were assessed using linear regression ***:Among the beta-lactam antibiotics studied,Escherichia coli exhibited varying levels of resistance,with cephalosporins showing higher resistance rates compared to *** pooled resistance rates were 66%for cefotaxime,65%for ceftriaxone,54%for ceftazidime,and 56%for *** contrast,carbapenems demonstrated lower resistance rates,with weighted pooled resistance rates ranging from 3%to 4%for meropenem,ertapenem,and *** rates were also observed for amoxicillin/clavulanate(35%),ticarcillin/clavulanate(26%),and piperacillin/tazobactam(12%).Significant annual increases in resistance were noted for imipenem(0.56%,Pions:this study highlights the critical issue of antimicrobial resistance in urinary tract infections in Vietnam and emphasizes the importance of prudent antibiotic use and the regular monitoring of resistance *** insights are useful for guiding healthcare professionals in optimizing treatment strategies and for policymakers in formulating evidence-based clinical guidelines to combat antibiotic resistance effectively.

关键词： Antimicrobial resistance Urinary tract infection Vietnam

A novel strategy for ionomer coating of Ag nanoparticles used for the electrochemical reduction of CO2 to CO in a membrane electrode assembly

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2024年第2期11卷 94-95页

作者： Alexis t.Bell Department of Chemical and Biomolecular Engineering University of California

the electrochemical reduction of the CO2reaction （CO2RR） offers an attractive means for converting the carbon content of CO2, released from a stationary source or the atmosphere, into fuels and chemicals [1]. Utiliz...

关键词：

A deep neural network based surrogate model for damage identification in full-scale structures with incomplete noisy measurements

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第3期18卷 393-410页

作者： tram BUi-NGOC Duy-Khuong LY tam t tRUONG Chanachai tHONGCHOM t.NGUYEN-tHOi Laboratory for Computational Mechanics Institute for Computational Science and Artificial IntelligenceVan Lang UniversityHo Chi Minh City 70000Vietnam Faculty of Mechanical-Electrical and Computer Engineering School of TechnologyVan Lang UniversityHo Chi Minh City 70000Vietnam Faculty of Civil Engineering School of TechnologyVan Lang UniversityHo Chi Minh City 70000Vietnam Department of Computer Science Aarhus UniversityAarhus 8000Denmark thammasat University research unit in structural and foundation engineering Department of Civil EngineeringThammasat UniversityPathumthani 12120Thailand Laboratory for Applied and industrial Mathematics Institute for Computational Science and Artificial IntelligenceVan Lang UniversityHo Chi Minh City 70000Vietnam thammasat School of Engineering Thammasat UniversityPathumthani 12120Thailand

the paper introduces a novel approach for detecting structural damage in full-scale structures using surrogate models generated from incomplete modal data and deep neural networks(DNNs).A significant challenge in this field is the limited availability of measurement data for full-scale structures,which is addressed in this paper by generating data sets using a reduced finite element(FE)model constructed by SAP2000 software and the MAtLAB programming *** surrogate models are trained using response data obtained from the monitored structure through a limited number of measurement *** proposed approach involves training a single surrogate model that can quickly predict the location and severity of damage for all potential *** achieve the most generalized surrogate model,the study explores different types of layers and hyperparameters of the training algorithm and employs state-of-the-art techniques to avoid overfitting and to accelerate the training *** approach’s effectiveness,efficiency,and applicability are demonstrated by two numerical *** study also verifies the robustness of the proposed approach on data sets with sparse and noisy measured ***,the proposed approach is a promising alternative to traditional approaches that rely on FE model updating and optimization algorithms,which can be computationally *** approach also shows potential for broader applications in structural damage detection.

关键词： vibration-based damage detection deep neural network full-scale structures finite element model updating noisy incomplete modal data