检索结果-南通市图书馆

A study on the Transmission Dynamics of the Omicron Variant of COVID-19 Using Nonlinear Mathematical 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

Computer Modeling in Engineering & sciences 2024年第6期139卷 2265-2287页

作者： s.Dickson s.Padmasekaran Pushpendra Kumar Kottakkaran sooppy Nisar Hamidreza Marasi Department of Mathematics Periyar UniversitySalemTamilnadu636011India Faculty of Engineering and Natural sciences Istanbul Okan UniversityIstanbulTurkey Department of Mathematics College of Science and Humanities in AlkharjPrince Sattam Bin Abdulaziz UniversityAlkharj11942Saudi Arabia Department of Applied Mathematics Faculty of MathematicsStatistics and Computer ScienceUniversity of TabrizTabrizIran

This research examines the transmission dynamics of the Omicron variant of COVID-19 using sEIQIcRVW and sQIRV models,considering the delay in converting susceptible individuals into infected *** significant delays eventually resulted in the pandemic’s *** ensure the safety of the host population,this concept integrates quarantine and the COVID-19 *** investigate the stability of the proposed *** fundamental reproduction number influences stability *** to our findings,asymptomatic cases considerably impact the prevalence of Omicron infection in the *** real data of the Omicron variant from Chennai,Tamil Nadu,India,is used to validate the outputs.

关键词： Omicron local stability reproduction number steady states global stability

Physics of porous materials under extreme laser-generated conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Matter and Radiation at Extremes 2024年第3期9卷 1-3页

作者： V.T.Tikhonchuk s.Weber Extreme Light Infrastructure ERIC ELI Beamlines Facility25241 DolníBrezanyCzech Republic CELIA University of Bordeaux33405 TalenceFrance

Porous materials offer unique possibilities for the production of plasmas with controlled density profiles for experiments on laser–matter *** are of growing relevance to many applications,such as inertial confinement fusion,fundamental research,and secondary *** the processes of transformation of a porous solid into a plasma is of fundamental interest and is needed for producing materials with desired properties.

关键词： interaction. properties. porous

Transjugular intrahepatic portosystemic shunt for recompensating decompensated cirrhosis?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2024年第20期30卷 2621-2623页

作者： Dimitrios s Karagiannakis Academic Department of Gastroenterology and Hepatology Medical School of National and Kapodistrian University of AthensGeneral Hospital of Athens“Laiko”Athens 11527Greece

Transjugular intrahepatic portosystemic shunt(TIPs)is a medical procedure that has been used to manage variceal bleeding and ascites in patients with *** can prevent further decompensation and improve the survival of high-risk decompensated *** research indicates that TIPs could increase the possibility of recompensation of decompensated cirrhosis when it is combined with adequate suppression of the causative factor of liver ***,the results of the studies have been based on retrospective analysis,and further validation is required by conducting randomized controlled *** this context,we highlight the limitations of the current studies and emphasize the issues that must be addressed before TIPs can be recommended as a potential recompensating tool.

关键词： Decompensated cirrhosis Liver recompensation Baveno VII Transjugular intrahepatic portosystemic shunt

Elevation transition of aquatic insects closely matches a thermal feature in the Yungas of Northwestern Argentina

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2期21卷 433-448页

作者： Alexandra BUITRAGO-GUACANAME Carlos MOLINERI Andrés LIRA-NORIEGA Daniel Andrés DOs sANTOs Neotropical Biodiversity Institute(CONICET-UNT) UNT-DomesHorco Molle S/N4107 TucumánArgentina CONACYT Research Fellow Network of Advanced Molecular StudiesInstitute of Ecology A.COld Road to Coatepec 351El HayaCP 91073XalapaVeracruzMexico Biostatistics Chair Faculty of Natural Sciences and IMLNational University of TucumánSan Miguel de TucumánMiguel Lillo 2054000 TucumánArgentina

Temperature is a key factor that shapes the distribution of *** knowledge about how species respond to temperature is relevant to devise strategies for addressing the impacts of climate *** insects are particularly vulnerable to climate change,yet there is still much to learn about their ecology and *** the Yungas ecoregion of Northwestern Argentina,cold-and warm-adapted species of the orders Ephemeroptera,Plecoptera,and Trichoptera(EPT)are segregated by *** modeled the ecological niche of south American EPT species in this region using available data and projected their potential distribution in geographic *** were grouped based on their ecogeographic similarity,and we analyzed their replacement pattern along elevation gradients,focusing on the ecotone where opposing thermal preferences *** this interface,we identified critical points where the combined incidence of cold and warm assemblages maximizes,indicating a significant transition *** found that the Montane Cloud Forest holds the interface,with a particularly greater suitability at its lower *** main axis of the interface runs in a N-s direction and falls between 14°C-16°C mean annual *** probability of a particular location within a basin being classified as part of the interface increases as Kira’s warmth index approaches a score around *** the interface is critical for defining the thermal limits of species distribution and designing biomonitoring *** in the location of thermal constants related to mountainous ecotones may cause vertical displacement of aquatic insects and vegetation *** have recognized significant temperature thresholds that serve as indicators of suitability for the *** global warming is anticipated to shift these indicators,we suggest using them to monitor the imprints of climate change on mountain ecosystems.

关键词： Austral Yungas Ecological Niche Model Ephemeroptera Kira’s warmth index Plecoptera Trichoptera

A Probabilistic Trust Model and Control Algorithm to Protect 6G Networks against Malicious Data Injection Attacks in Edge Computing Environments

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & sciences 2024年第10期141卷 631-654页

作者： Borja Bordel sánchez Ramón Alcarria Tomás Robles Department of Computer systems Universidad Politécnica de MadridMadrid28031Spain Department of Geospatial Engineering Universidad Politécnica de MadridMadrid28031Spain

Future 6G communications are envisioned to enable a large catalogue of pioneering *** will range from networked Cyber-Physical systems to edge computing devices,establishing real-time feedback control loops critical for managing Industry 5.0 deployments,digital agriculture systems,and essential *** provision of extensive machine-type communications through 6G will render many of these innovative systems autonomous and *** full automation will enhance industrial efficiency significantly,it concurrently introduces new cyber risks and *** particular,unattended systems are highly susceptible to trust issues:malicious nodes and false information can be easily introduced into control ***,Denialof-service attacks can be executed by inundating the network with valueless *** anomaly detection schemes require the entire transformation of the control software to integrate new steps and can only mitigate anomalies that conform to predefined mathematical *** based on an exhaustive data collection to detect anomalies are precise but extremely *** models,with their limited understanding of mobile networks,can achieve precision rates no higher than 75%.Therefore,more general and transversal protection mechanisms are needed to detect malicious behaviors *** paper introduces a probabilistic trust model and control algorithm designed to address this *** model determines the probability of any node to be *** channels are pruned for those nodes whose probability is below a given *** trust control algorithmcomprises three primary phases,which feed themodel with three different probabilities,which are weighted and ***,anomalous nodes are identified using Gaussian mixture models and clustering ***,traffic patterns are studied using digital Bessel functions and the functional scalar ***,the in

关键词： 6G networks noise injection attacks Gaussian mixture model Bessel function traffic filter Volterra filter

Parametric investigation on the novel and cost-effective nano fly ash impregnated geopolymer system for sustainable construction

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 structural and Civil Engineering 2024年第2期18卷 170-183页

作者： R.MOHANA s.M.Leela BHARATHI Department of Civil Engineering Mepco Schlenk Engineering CollegeSivakasi 626123India

The hazardous environmental effects of greenhouse gas emissions and climate change demand alternative sources for cementitious materials in the construction *** development of geopolymer structures provides a way of producing 100%cement-free *** this research work,a novel and simple way of deriving nano particles from waste fly ash particles is *** effect of adding the synthesized nano fly ash particles as a filler medium in geopolymer mortars was investigated by considering strength and durability *** optimization was done by using regression analysis on the geopolymer mortar and the impact of adding nano fly ash particles was studied by varying different percentages of addition ranging from 0 to 7.5%by weight of binder *** the results,it was observed that 1%nano fly ash acted not only as a filler but also as nano-sized precursors of the polymerization process,resulting in denser geopolymer *** can explain the extraordinary gain in strength of 72.11 MPa as well as the denser core with negligible level of chloride ion penetration,making the material suitable for the development of structures susceptible to marine environment.

关键词： geopolymer nano fly ash chloride ion penetration durability polymerization fillers

Visible light-driven photo remediation of hazardous cationic dye via Ce-doped WO_(3) nanostructures

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5期42卷 869-878,I0003页

作者： Azra Haroon Kaseed Anwar Arham s.Ahmed Department of Physics Aligarh Muslim University202002AligarhIndia Interdisciplinary Nanotechnology Centre Aligarh Muslim University202002AligarhIndia

Ce-doped WO_(3) nanoparticles were successfully synthesized by the sol-gel method and characterized through advanced characterization *** high resolution transmission electron microscopy(HRTEM)and scanning electron microscopy(sEM)results show a reduction in the agglomeration of nanoparticles upon *** energy dispersive X-ray(EDX)analysis validates the existence of the Ce element in all the doped samples.X-ray photoelectron spectroscopy(XPs)and Raman spectra justify the presence of structural defects(oxygen vacancies)and successful formation of the monoclinic WO_(3) phase,*** Kubelka-Munk function indicates a decrease in band gap with doping,while photoluminescence(PL)spectra show intense visible and UV emissions,significantly,all doped samples exhibit higher photocatalytic performance than pure WO_(3) nanoparticles,with the 6 wt%Ce-doped sample displaying the highest degradation *** with Ce can help to increase the surface area of WO_(3),thereby improving its photoactivity,Moreover,a correlation between PL and photocatalysis is established in the light of oxygen vacancies suggesting a direct dependence of high photocatalytic activity on strong PL signals of WO_(3) *** experiments further reveal that the degradation process is primarily driven by active species,providing insight into a plausible photocatalytic mechanism.

关键词： WO_(3) Rare-earth element Environmental crisis Oxygen vacancies Luminescence Photocatalysis

Improved state-space Modelling for Microgrids Without Virtual Resistances

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power systems and Clean Energy 2024年第2期12卷 584-596页

作者： Paranagamage s.A.Peiris shaahin Filizadeh Dharshana Muthumuni Department of Electrical and Computer Engineering University of ManitobaWinnipegMBR3T 5V6Canada Manitoba HVDC Research Center 211 Commerce DriveWinnipegMBR3P 1A3Canada IEEE

Power converters and their interfacing networks are often treated as modular state-space blocks for small-signal stability studies in microgrids;they are interconnected by matching the input and output states of the network and *** resistors have been widely used in existing models to generate a voltage for state-space models of the network that require voltage *** paper accurately quantifies the adverse impacts of adding the virtual resistance and proposes an alternative method for network modelling that eliminates the requirement of the virtual resistor when interfacing converters with *** proposed nonlinear method allows initialization,time-domain simulations of the nonlinear model,and linearization and eigenvalue generation.A numerically linearized small-signal model is used to generate eigenvalues and is compared with the eigenvalues generated using the existing modelling method with virtual *** of the existing method and improvements offered by the proposed modelling method are clearly *** transient(EMT)simulations using detailed switching models are used for validation of the proposed modelling method.

关键词： Low-voltage converter state-space modelling dynamic phasor time-domain simulation eigenvalue analysis

A study of the Comets with Large Perihelion Distances C/2019 L3(ATLAs)and C/2019 O3(Palomar)

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第9期24卷 199-213页

作者： Alberto s.Betzler Centro de Ciencia e Tecnologia em Energia e sustentabilidade Universidade Federal do Recôncavo da BahiaFeira de SantanaBahia44.085-132Brazil

This work analyzes the photometric data of the Oort spike comets C/2019 L3(ATLAs)and C/2019 O3(Palomar)obtained between 2016 and 2023 by the ATLAs network and the Belgian Olmen *** comets Palomar and ATLAs have a typical and unusually high activity level,respectively,based on the Afρparameter corrected to phase angle zero at *** absolute magnitude of comets ATLAs and Palomar in the o-band is 4.71±0.05 and 4.16±0.02 *** cometary activity of comets ATLAs and Palomar probably began at r>13 au before perihelion and will end at r>14 au after perihelion,which means that they could remain active until the second half of *** nucleus of comet ATLAs has a minimum radius of 7.9 km,and the nucleus of comet Palomar could be a little *** c-o colors of the comets ATLAs and Palomar are redder and bluer,respectively,at perihelion than the solar twin YBP *** comets showed a bluish trend in the coma color with decreasing heliocentric *** Palomar probably had two outbursts after its perihelion,each releasing about 10^(8)kg of *** slopes of the photometric profile of the comae of these comets were between 1and 1.5,indicating a steady state during the observation campaign.

关键词： individual C/2019 L3(ATLAs) C/2019 O3(Palomar) techniques:photometric methods:data analysis