检索结果-南通市图书馆

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

在线全文

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

Anisotropic extensions of isotropic Finch–Skea metric in the charged modified gravity

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第9期76卷 120-142页

作者： Tayyab Naseer m Sharif Department of mathematics and Statistics The University of Lahore

In this study, we explore the Finch–Skea perfect fluid solution and extend its domain to three distinct anisotropic interior models within the framework of the f(R, T) theory, incorporating the influence of an electromagnetic field. We assume a static spherical spacetime initially coupled with an isotropic matter distribution. We then introduce a Lagrangian corresponding to an additional gravitating source, taking into account its role in inducing pressure anisotropy within the original fluid source. By deriving the field equations for the combined matter setup, we applied a radial component transformation, which yielded two distinct systems of equations. In addition, we consider a charged exterior spacetime to determine the three constants associated with the Finch–Skea solution at the boundary. Our findings suggest that under certain parametric choices, all three resulting models exhibited physical relevance within this modified theory.

关键词： anisotropy gravitational decoupling modified gravity

4He monolayer on graphene: a quantum monte Carlo study

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第9期76卷 151-159页

作者： S Yu m Boninsegni Department of Physics University of Alberta

We revisit the problem of adsorption of a single4He layer on graphene, focusing on the commensurate(C1/3) crystalline phase, specifically on whether it may possess a nonzero superfluid response, and on the existence of superfluid phases, either（metastable） liquid or vacancy-doped crystalline. We make use of canonical quantum monte Carlo simulations at zero and finite temperature, based on a realistic microscopic model of the system. Our results confirm the absence of any superfluid response in the commensurate crystal, and that no thermodynamically stable uniform phase exists at lower coverage. No evidence of a possibly long-lived, metastable superfluid phase at C1/3coverage is found. Altogether, the results of ground-state projection methods and finite-temperature simulations are entirely consistent.

关键词： helium low-dimensional systems quantum monte Carlo superfluidity supersolids

Gedunin attenuates streptozotocin-induced diabetic hepatopathy in rats

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2024年第7期14卷 288-297页

作者： Suchismita mazumdar Thankamani m marar Jyoti m Patki School of Biotechnology and Bioinformatics D.Y.Patil Deemed to be UniversityNavi Mumbai 400614India

Objective:To examine the hepatoprotective effects of gedunin in streptozotocin(STZ)-induced diabetic ***:Rats were divided into 4 groups:control,STZ,gedunin,and STZ+*** parameters for liver function and liver histology were *** molecular interaction of gedunin with the liver glucose transporters GLUT2 and SGLT1 was examined using AutoDock ***:Gedunin attenuated STZ-induced increase in the levels of aspartate transaminase,alanine transaminase,alkaline phosphatase,lactate dehydrogenase and gamma-glutamyl transferase in the serum and liver tissue,reduced lipid peroxidation,and enhanced antioxidant *** studies showed considerable restoration of liver architecture in gedunin-treated diabetic *** silico studies revealed stable binding of gedunin with GLUT2 and ***:Gedunin exerts hepatoprotective effects in STZ-induced diabetic rats by reducing liver enzymatic activities and oxidative *** studies are warranted to verify the mechanism of its hepatoprotective action.

关键词： Gedunin GLUT2 SGLT1 Diabetic hepatopathy Docking Histology Homology modelling

Tensile deformation of fine-grained mg at 4K,78K and 298K

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 magnesium and Alloys 2024年第6期12卷 2534-2556页

作者： m.Walag A.Kula P.Noga T.Tokarski G.Cios m.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland materials Science and Engineering McMaster UniversityHamiltonCanada

The impact of grain size,ranging from 0.9μm to 9μm,on the mechanical properties of commercially pure mg is investigated at temperatures of 4K,78K,and *** mechanisms governing plastic flow are influenced by both grain size and *** 4K and 78K,dominant deformation modes in mg involve dislocation glide and extension twinning,regardless of grain *** interactions between basal and non-basal dislocations and dislocations with grain boundaries promote an unusually high rate of work hardening in the plastic regime,leading to premature *** yield stress follows the Hall-Petch relationshipσ_(y)∼k/√d,with the slope k increasing with decreasing *** 298K,in addition to dislocation glide and twinning,grain boundary sliding(GBS)becomes significant in samples with grain sizes below 3μm,considerably enhancing the material’s *** activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries,facilitating their absorption during sliding and *** ofσrelationship suggests that the basal slip is the dominant dislocation mode in mg at *** grain size suppresses dislocation activity and twinning and increases GBS,resulting in lowerandσ*** conventional deformation modes coupled with enhanced GBS yields stress softening,breaking down the Hall-Petch relationship in mg below 3μm grain size,leading to an inverse Hall-Petch *** work reports new data on the strength,ductility,work hardening and fracture behaviour,and their variations with mg grain size across different temperature regimes.

关键词： Polycrystalline mg mechanical properties Deformation mechanisms Work-hardening Texture evolution Cryogenic temperatures Hall-Petch relationship

Solute transport and geochemical modeling of the coastal quaternary aquifer, Delta Dahab Basin, South Sinai, Egypt

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2024年第1期43卷 16-39页

作者： Amira Samy mustafa Eissa Seham Shahen moustafa m.Said Rabab m.Abou-shahaba Division of Water Resources and Arid Land Department of HydrogeochemistryDesert Research CenterCairoEgypt Egypt Desalination Research Center of Excellence Desert Research CenterCairoEgypt Center for Water Supply Studies S&E-Physical&Environmental SciencesTexas A&M University Corpus ChristiCorpus ChristiUSA Department of Chemistry Faculty of Science(Girls)Al-Azhar UniversityYousef Abbas StrNasr CityP.O.Box:11754CairoEgypt

The wadi dahab delta is in a dry, arid coastal zone within Egypt’s south Sinai Peninsula’s eastern portion. The primary water source is the Quaternary coastal alluvial aquifer. The groundwater salinity varies from 890to 8213 mg/L, with a mean value of 3417 mg/L. The dissolved major ions have been used to calculate the seawater mixing index(SWmI) using a linear equation that discriminates the groundwater mostly affected by water–rock interaction(SWmI 1>) and other samples mixed with Seawater(SWmI mposition of groundwater for specifically chosen groundwater samples ranges from-0.645‰ to +5.212‰ for δ^(18)O and from-9.582‰ to + 22.778‰ for δ^(2)H, where the seawater represented by a Red Sea water sample(δ^(18)O + 1.64‰-δ^(2)H + 9.80‰) and reject brine water are considerably enriched the isotopic groundwater values. The geochemical NETPATH model constrained by the dissolved significant ions, isotopes, and the rock aquifer forming minerals as phases indicate the mixing percent with the seawater ranges from 9% to 97% of seawater from 91% to 3% of original recharge water. According to the SEAWAT 3-D flow models, seawater has penetrated the Northeastern Dahab delta aquifer, with the intrusion zone extending1500 m inland. The salt dissolution, upwelling of saline water, recharge from the upstream mountain block, and seawater encroachment are the primary aspects contributing to the deterioration of groundwater quality. These findings may have significance for effective groundwater withdrawal management in arid locations worldwide with similar hydrogeological systems.

关键词： Groundwater geochemistry Seawater intrusion Solute transport SEAWAT

Vaccination effect on a stochastic epidemic model with healing and relapse

在线全文

学校读者我要写书评

暂无评论

International Journal of Biomathematics 2024年第1期17卷 29-59页

作者： m.m.Abdeslami L.Basri m.El Fatini I.Sekkak R.Taki Laboratory of Partial Differential Equations Spectral Algebra and Geometry Department of mathematics Faculty of Sciences Ibn Tofail UniversityBP 133KénitraMorocco Centre de Recherche en Sante Publique montréal(Québec)H3N 1X9 Canada Departement de Medecine Sociale et Preventive Ecole de SantéPublique de I'Universitéde Montreal 101Avenue du ParcMontréal(Quebec)H3N 1X9Canada EST Sidi Bennour Chouaib Doukkali UniversityEl JadidaMorocco

In this work,we consider a stochastic epidemic model with vaccination,healing and *** prove the existence and the uniqueness of the positive *** establish sufficient conditions for the extinction and the persistence in mean of the stochastic ***,we also establish sufficient conditions for the existence of ergodic stationary distribution to the model,which reveals that the infectious disease will *** graphical illustrations of the approximate solutions of the stochastic epidemic model have been performed.

关键词： Stochastic epidemic model with relapse and healing vaccination extinction persistence in mean markov semigroup stationary distribution

Growth of RB Population in the Conversion Phase of Chlamydia Life Cycle

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Communications on Applied mathematics and Computation 2024年第1期6卷 90-112页

作者： Frederic Y.m.Wan Department of mathematics University of CaliforniaIrvineCA92697-3875USA

Upon infecting a host cell,the reticulate body(RB)form of the Chlamydia bacteria simply proliferates by binary fission for an extended *** data show only RB units in the infected cells 20 hours post infection(hpi),spanning nearly half way through the development *** data collected every 4 hpi,conversion to the elementary body(EB)form begins abruptly at a rapid rate sometime around 24 *** modeling proliferation and conversion as simple birth and death processes,it has been shown that the optimal strategy for maximizing the total(mean)EB population at host cell lysis time is a bang-bang control qualitatively replicating the observed conversion ***,the simple birth and death model for the RB proliferation and conversion to EB deviates in a significant way from the available data on the evolution of the RB population after the onset of RB-to-EB *** working with a more refined model that takes into account a small size threshold eligibility requirement for conversion noted in the available data,we succeed in removing the deficiency of the previous models on the evolution of the RB population without affecting the optimal bang-bang conversion strategy.

关键词： Chlamydia Life cycle Optimal control maximal infectious spread Specie competitive survival

multichannel coupling induced topological insulating phases with full multimerization

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第3期12卷 491-498页

作者： JUN LI YAPING YANG C-m.HU mOE Key Laboratory of Advanced micro-Structured materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Physics and Astronomy University of ManitobaWinnipegManitoba R3T 2N2Canada

We propose and experimentally realize a class of quasi-one-dimensional topological lattices whose unit cells are constructed by coupled multiple identical resonators,with uniform hopping and inversion *** the presence of coupling-path-induced effective zero hopping within the unit cells,the systems are characterized by complete multimerization with degenerate-1 energy edge states for open boundary condition.

关键词： symmetry topological coupling