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Evaluation of the remaining lateral torsional buckling capacity in corroded steel members

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第11期11卷 887-897页

作者： yasser SHARIfI Reza RAHGOZAR Department of Civil Engineering Kerman University

Corrosion is one of the main causes of deterioration in steel structures. Loss of thickness in flanges and web of corroded steel beams leads to reduction in section properties which can reduce the lateral torsional buckling capacity of the member. In this paper, thickness loss data were compiled from four samples of corrosion damaged I-beams removed from a petro-chemical plant. Visual examination of the four corroded beams showed that they were corroded uniformly. To improve the accuracy of the results, a large number of measurements for surface roughness were taken for each beam, totally 770 values to obtain the average thickness of flanges and web of each beam. The data was used to develop a corrosion decay model in order to calculate the percentage remaining lateral torsional buckling capacity of long and short span beams which are laterally unrestrained. To estimate the percentage of remaining lateral torsional buckling capacity in the corroded damaged I-beams, the readily available minimum curves for different types of universal beams in conjunction with information on the thickness loss were used. The results can be used by practicing engineers for better estimation on the service life of deteriorated steel structures.

关键词： Corrosion Steel structures Lateral torsional buckling Beams

Layered Potassium Titanium Niobate/Reduced Graphene Oxide Nanocomposite as a Potassium‑Ion Battery Anode

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Nano-Micro Letters 2024年第1期16卷 1-16页

作者： Charlie A.f.Nason Ajay Piriya Vijaya Kumar Saroja Yi Lu Runzhe Wei Yupei Han Yang Xu Department of Chemistry University College London20 Gordon StreetLondon WC1H 0AJUK

With graphite currently leading as the most viable anode for potassium-ion batteries(KIBs),other materials have been left relatively *** metal oxides are among these,with many positive attributes such as synthetic maturity,longterm cycling stability and fast redox ***,to address this research deficiency we report herein a layered potassium titanium niobate KTiNbO5(KTNO)and its rGO nanocomposite(KTNO/rGO)synthesised via solvothermal methods as a high-performance anode for *** effective distribution across the electrically conductive rGO,the electrochemical performance of the KTNO nanoparticles was *** potassium storage performance of the KTNO/rGO was demonstrated by its first charge capacity of 128.1 mAh g^(−1) and reversible capacity of 97.5 mAh g^(−1) after 500 cycles at 20 mA g^(−1),retaining 76.1%of the initial capacity,with an exceptional rate performance of 54.2 mAh g^(−1)at 1 A g^(−1).furthermore,to investigate the attributes of KTNO in-situ XRD was performed,indicating a low-strain ***-situ X-ray photoelectron spectra further investigated the mechanism of charge storage,with the titanium showing greater redox reversibility than the *** work suggests this lowstrain nature is a highly advantageous property and well worth regarding KTNO as a promising anode for future high-performance KIBs.

关键词： Potassium-ion batteries Intercalation Transition metal oxides Anodes Nanocomposite

Comparisons of oxbow lake fish assemblages in relation to bigheaded carp establishment in the lower White River, Arkansas

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Ecological Processes 2024年第1期13卷 188-205页

作者： Michael A.Eggleton Cody J.Salzmann Joseph E.Kaiser Shannon C.f.Smith Department of Aquaculture and fisheries University of Arkansas at Pine Bluff Arkansas Game and fish Commission Virginia Institute of Marine Science

Background Since the late 1990s, bigheaded carps(largely silver carp [Hypophthalmichthys molitrix] but also bighead carp [H. nobilis]) have established throughout the lower Mississippi River basin. Using previously studied oxbow lakes in the lower White River basin, Arkansas, we compared current(2017, “post-carp” establishment) fish assemblages to historical(2002, “pre-carp” establishment) fish assemblages. fish assemblages were comprehensively assessed using multiple gears, including boat electrofishing, mini-fyke nets, and experimental small-mesh gill *** T-tests suggested that fish assemblage indices of richness, diversity, evenness, and dominance were often greater(P flected by boat electrofishing and experimental gill nets. However, all indices were generally similar(P > 0.05) between the pre-carp and post-carp period with fish assemblages depicted using mini-fyke nets. Nonmetric multidimensional scaling analyses indicated that fish assemblages differed structurally between pre-carp and post-carp periods. Assemblage differences were linked to both small and large abundance changes for more than 20 species. Abundances of gizzard shad(Dorosoma cepedianum), emerald shiner(Notropis atherinoides), pugnose minnow(Opsopoeodus emiliae), crappies(Pomoxis spp.), bluegill(Lepomis macrochirus), orangespotted sunfish(L. humilis), and yellow bass(Morone mississippiensis) declined between the pre-carp and postcarp periods. Conversely, abundances of weed shiner(N. texanus), pallid shiner(Hybopsis amnis), longear sunfish(L. megalotis), buffalofishes(Ictiobus spp.), and gars(Lepisosteus spp.) generally increased during the same *** Although not possible to conclude assemblage shifts were entirely related to bigheaded carps due to the absence of an appropriate reference system where carps did not establish, the wide establishment of these carps is one of the most pervasive changes to have occurred in the lower White

关键词： Bigheaded carp Silver carp Aquatic nuisance species fish assemblage Oxbow lake Large river

Dynamics of Optical Bistability with Kerr-nonlinear Blackbody Radiation Reservoir

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Communications in Theoretical Physics 2017年第4期67卷 435-442页

作者： yasser A.Sharaby Suez University Faculty of SciencesPhysics DepartmentSuezEgypt

In this paper we investigate the nonlinear dynamics for optical bistabile(OB) model of homogeneously broadened two-level atomic medium interacting with a single mode of the ring cavity in the presence of a Kerr-nonlinear blackbody(KNB) radiation reservoir. We show the impact of the relative temperature of the reservoir on the transition between the dynamical states via bifurcation diagrams that represents the relation between maximum values of the output field and the relative temperature for fixed input field. Specifically, decreasing the relative temperature(T_b)causes the system to bifurcate from periodic to chaotic behavior and in turn reverts back to periodic behavior with further decrease of T_b. Varying atomic detuning leads to a change in the nature of the dynamic transition between the system's states from self pulsing to chaotic behavior.

关键词： optical bistability Kerr-nonlinear blackbody reservoir bifurcation nonlinear dynamics self pulsing chaos

A predictive model for ethylene-mediated auxin and cytokinin patterning in the Arabidopsis root

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Plant Communications 2024年第7期5卷 120-137页

作者： Simon Moore George Jervis Jennifer f.Topping Chunli Chen Junli Liu Keith Lindsey Department of Biosciences Durham UniversitySouth RoadDurham DH13LEUK Hubei Hongshan Laboratory College of Life Science and TechnologyHuazhong Agricultural UniversityWuhan 430070China National Key Laboratory for Germplasm Innovation and Utilization for fruit and Vegetable Horticultural Crops Huazhong Agricultural UniversityWuhanHubei 430070China

The interaction between auxin and cytokinin is important in many aspects of plant *** measurements of both auxin and cytokinin concentration and reporter gene expression clearly show the coexistence of auxin and cytokinin concentration patterning in Arabidopsis root ***,in the context of crosstalk among auxin,cytokinin,and ethylene,little is known about how auxin and cytokinin concentration patterns simultaneously emerge and how they regulate each other in the Arabidopsis *** work utilizes a wide range of experimental observations to propose a mechanism for simultaneous patterning of auxin and cytokinin *** addition to revealing the regulatory relationships between auxin and cytokinin,this mechanism shows that ethylene signaling is an important factor in achieving simultaneous auxin and cytokinin patterning,while also predicting other experimental *** the mechanism with a realistic in silico root model reproduces experimental observations of both auxin and cytokinin *** made by the mechanism can be compared with a variety of experimental observations,including those obtained by our group and other independent experiments reported by other *** of these predictions include patterning of auxin biosynthesis rate,changes in PIN1 and PIN2 patterns in pin3,4,7 mutants,changes in cytokinin patterning in the pls mutant,PLS patterning,and various trends in different *** research reveals a plausible mechanism for simultaneous patterning of auxin and cytokinin concentrations in Arabidopsis root development and suggests a key role for ethylene pattern integration.

关键词： Arabidopsis root auxin patterning cytokinin patterning ethylene signaling in silico digital root spatiotemporal modeling

The global stability and optimal control of the COVID-19 epidemic model

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International Journal of Biomathematics 2024年第1期17卷 1-28页

作者： fengsheng Chien Hassan Saberi Nik Mohammad Shiraziant J.f.Gomez-Aguilar School of finance and Accounting fuzhou University of International Studies and Trade fuzhou 352020 P.R.China faculty of Business City university of Macao Macao 999078P.R.China Department of Mathematics and Statistics University of Neyshabur NeyshaburIran CONACyT-Tecnologico Nacional de Mécico/CENIDET Interior Internado Palmira S/N Col.Palmira C.P.62490CuernavacaMorelosMérico

This paper considers stability analysis of a Susceptible-Exposed-Infected-Recovered-Virus(SEIRV)model with nonlinear incidence rates and indicates the severity and weakness of control factors for disease *** Lyapunov function using Volterra-Lyapunov matrices makes it possible to study the global stability of the endemic equilibrium *** optimal control strategy is proposed to prevent the spread of coronavirus,in addition to governmental *** objective is to minimize together with the quantity of infected and exposed individuals while minimizing the total costs of treatment.A numerical study of the model is also carried out to investigate the analytical results.

关键词： Global stability SEIRV epidemic model dynamical systems Volterra-Lyapunov stability optimal control

Cooperative THz communication for UAVs in 6G and beyond

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Green Energy and Intelligent Transportation 2024年第1期3卷 25-31页

作者： Nazifa Mustari Muhammet Ali Karabulut A.f.M.Shahen Shah Ufuk Tureli Department of Electronics and Communication Engineering Yildiz Technical UniversityTurkey Department of Electrical Electronics Engineering Faculty of Engineering and ArchitectureKafkas UniversityKarsTurkey

One of the key components of any smart city is considered to be its intelligent transportation systems(ITSs).Unmanned aerial vehicles(UAVs)are envisioned in several ITS application fields because of their autonomous operation,mobility,communication/processing capabilities,and other *** this paper,cooperative terahertz(THz)communication is proposed for flying ad hoc networks(fANETs),which is a particular kind of network made up of a collection of small UAVs linked in an ad hoc fashion and working together to accomplish high-level *** frequency spectrum for wireless communication has been expanding continuously in order to meet the demand for *** the forthcoming 6G and beyond,communications in the THz range will be vital,similar to how mmWave-band communications are currently influencing the 5G of wireless mobile *** finite state machine(fSM)of the proposed cooperative communication system for THz band is presented.A Markov chain model-based analytical study is carried out,which derives relationships among ***,numerical results are provided to support the analytical study.

关键词： Cooperative MAC THz UAVs 6G

Increasing age and duration of sex work among female sex workers in South Africa and implications for HIV incidence estimation:Bayesian evidence synthesis and simulation exercise

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Infectious Disease Modelling 2024年第1期9卷 263-277页

作者： Nanina Anderegg Mariette Slabbert Kholi Buthelezi Leigh f.Johnson Centre for Infectious Disease Epidemiology and Research School of Public HealthUniversity of Cape TownSouth Africa Institute of Social and Preventive Medicine University of BernSwitzerland Independent Consultant PretoriaSouth Africa National Sex Workers Movement in South Africa

Introduction:In sub-Saharan Africa,accurate estimates of the HIV epidemic in female sex workers are crucial for effective prevention and care *** estimates are typically derived from mathematical models that assume certain demographic and behavioural characteristics like age and duration of sex work to remain constant over *** reviewed this assumption for female sex workers in South ***:We reviewed studies that reported estimates on either the age or the duration of sex work among female sex workers in South *** used Bayesian hierarchical models to synthesize reported estimates and to study time *** a simulation exercise,we also investigated the potential impact of the"constant age and sex work duration"-assumption on estimates of HIV ***:We included 24 different studies,conducted between 1996 and 2019,contributing 42 estimates on female sex worker age and 27 estimates on sex work *** was evidence suggesting an increase in both the duration of sex work and the age of female sex workers over *** to the fitted models,over each decade the expected duration of sex work increased by 55.6%(95%-credible interval[CrI]:23.5%–93.9%)and the expected age of female sex workers increased by 14.3%(95%-CrI:9.1%–19.1%).Over the 23-year period,the predicted mean duration of sex work increased from 2.7 years in 1996 to 7.4 years in 2019,while the predicted mean age increased from 26.4 years to 32.3 *** for these time trends in the simulation exercise resulted in a notable decline in estimated HIV incidence rate among sex workers over *** decline was significantly more pronounced than when assuming a constant age and duration of sex ***:In South Africa,age and duration of sex work in female sex workers increased over *** this trend might be influenced by factors like expanding community mobilization and improved rights advocacy,the ongoing criminalisation,stigmatisation of s

关键词： female sex workers Mathematical modelling South Africa HIV

Small molecular decoys in Alzheimer's disease

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Neural Regeneration Research 2024年第8期19卷 1658-1659页

作者： Sho Oasa Valentina L.Kouznetsova Igor f.Tsigelny Lars Terenius Department of Clinical Neuroscience Center for Molecular MedicineKarolinska InstitutetStockholmSweden San Diego Supercomputer Center University of California San DiegoLa JollaCAUSA Department of Neurosciences University of California San DiegoLa JollaCAUSA Department of Clinical Neuroscience Karolinska University HospitalKarolinska InstitutetStockholmSweden

Recent progress in the treatment of Alzheimer’s disease(AD)using antibodies against amyloid sustains amyloid generation as a key process in *** formation starts with two amyloidbeta(Aβ)molecules interacting(dimer formation)followed by an accelerating build-up of socalled protofibrils,which turn into fibrils,which accumulate in the characteristic plaques.

关键词： Alzheimer decoy Aβ