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Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： N.d.NGUYEN T.N.NGUYEN Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and Technology Kien Giang UniversityChau Thanh 92000Viet Nam

This study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(Td)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBT)

viscoelastic potential flow instability theory of Rivlin-Ericksen electrified fluids of cylindrical interface

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Journal of Ocean Engineering and Science 2024年第4期9卷 311-316页

作者： d.M.Mostafa department of Mathematics College of ScienceQassim UniversityPO Box 6644Buraidah 51452Saudi Arabia department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt

A linear electrohydrodynamic Kelvin-Helmholtz instability of the interface between two viscoelastic Rivlin-Ericksen fluids enclosed by two concentric horizontal cylinders has been studied via the viscoelastic potential flow *** dispersion equation of complex coefficients for asymmetric disturbance has been obtained by using normal mode *** stability criteria are analyzed theoretically and illustrated *** imaginary part of growth rate is plotted versus the wave *** influences of dynamic viscoelastic,uniform velocities,Reynolds number,electric field,dynamic viscosity,density fluids ratio,dielectric constant ratio and inner fluid fraction on the stability of the system are *** study finds its significance in Ocean pipelines to transfer oil or gas such as Eastern Siberia-Pacific Ocean oil pipeline.

关键词： Rivlin-Ericksen fluid Cylindrical flow viscoelastic potential flow Electrohydrodynamics stability

Hepatolithiasis:Epidemiology,presentation,classification and management of a complex disease

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World Journal of Gastroenterology 2024年第13期30卷 1836-1850页

作者： Rodrigo v.Motta Francesca Saffioti vasileios K Mavroeidis Translational Gastroenterology and Liver Unit Nuffield Department of MedicineUniversity of OxfordOxford OX39DUUnited Kingdom department of Gastroenterology and Hepatology Oxford University Hospitals NHS Foundation TrustJohn Radcliffe HospitalOxford OX39DUUnited Kingdom UCL Institute for Liver and digestive Health and Sheila Sherlock Liver Unit Royal Free Hospital and University College LondonLondon NW32QGUnited Kingdom department of HPB Surgery Bristol Royal InfirmaryUniversity Hospitals Bristol and Weston NHS Foundation TrustBristol BS28HWUnited Kingdom department of Transplant Surgery North Bristol NHS TrustSouthmead HospitalBristol BS105NBUnited Kingdom department of Gastrointestinal Surgery North Bristol NHS TrustSouthmead HospitalBristol BS105NBUnited Kingdom

The term hepatolithiasis describes the presence of biliary stones within the intrahepatic bile ducts,above the hilar confluence of the hepatic *** disease is more prevalent in Asia,mainly owing to socioeconomic and dietary factors,as well as the prevalence of biliary *** the last century,owing to migration,its global incidence has *** main pathophysiological mechanisms involve cholangitis,bile infection and biliary strictures,creating a self-sustaining cycle that perpetuates the disease,frequently characterised by recurrent episodes of bacterial infection referred to as syndrome of“recurrent pyogenic cholangitis”.Furthermore,long-standing hepatolithiasis is a known risk factor for development of intrahepatic *** classifications have aimed at providing useful insight of clinically relevant aspects and guidance for *** management of symptomatic patients and those with complications can be complex,and relies upon a multidisciplinary team of hepatologists,endoscopists,interventional radiologists and hepatobiliary surgeons,with the main goal being to offer relief from the clinical presentations and prevent the development of more serious *** comprehensive review provides insight on various aspects of hepatolithiasis,with a focus on epidemiology,new evidence on pathophysiology,most important clinical aspects,different classification systems and contemporary management.

关键词： Cholelithiasis Intrahepatic stones Cholangiocarcinoma Biliary parasites Recurrent pyogenic cholangitis Oriental cholangiohepatitis Hepatectomy Cholangioscopy Liver transplant Paediatric

Classification of Rings Associated with the Genus of Clean Graphs

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Algebra Colloquium 2024年第3期31卷 451-466页

作者： v.Ramanathan C.Selvaraj Aaqib Altaf S.Pirzada department of Mathematics Periyar UniversitySalem 636011Tamil NaduIndi department of Mathematics University of KashmirHazratbalSrinagarKashmirIndia

Let R be a ring(not necessarily commutative)with identity 1 and let CL(R)be its clean *** this paper,we investigate the genus number of the compact Riemann surface in which CL(R)can be embedded and explicitly determine all commutative rings R(up to isomorphism)such that CL(R)has genus at most *** is shown that for any Artinian ring R,CL(R)is a projective graph if and only if R is isomorphic to ***,we determine all isomorphism classes of commutative rings whose clean graphs have crosscap two.

关键词： clean graph commutative ring planar graph genus crosscap

Nanomotion of bacteria to determine metabolic profile

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Nanotechnology and Precision Engineering 2024年第1期7卷 1-9页

作者： S.N.Pleskova E.v.Lazarenko N.A.Bezrukov R.N.Kriukov A.v.Boryakov M.E.dokukin S.I.Surodin Research Laboratory of Scanning Probe Microscopy Lobachevsky State University of Nizhny NovgorodNizhny Novgorod 603950Russia department of Nanotechnology and Biotechnology Nizhny Novgorod State Technical University n.a.R.E.AlekseevNizhny Novgorod 603950Russia Sarov Physics and Technology Institute National Research Nuclear University MEPhISarov 607186Russia

In addition to their visible motion such as swimming(e.g.,with the help ofﬂagella),bacteria can also exhibit nanomotion that is detectable only with highly sensitive instruments,and this study shows that it is possible to detect bacterial nanomotion using an AFM detection *** results show that the nanomotion characteristics depend on the bacterial strain,and that nanomotion can be used to sense the metabolic activity of bacteria because the oscillations are sensitive to the food preferences of the bacteria and the type of surrounding medium.

关键词： Nanomotion Bacteria Cantilever Oscillation Atomic force microscopy Metabolism

Flexible ultra-thin super-resolution endoscopy

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 171-172页

作者： George S.d.Gordon department of Electrical and Electronic Engineering University of NottinghamNottingham NG7 2RDUK

In recent years, multimode fiber(MMF) has become an important tool for high-resolution endoscopic imaging in narrow channels(e.g., in the brain via needles or inside blood vessels) due to its high mode density and fine diameter, typically ver, a major obstacle to widespread deployment in applications is that realistic perturbations, including bending, twisting and changes in temperature, cause unacceptable image degradation.

关键词： fiber resolution typically

Stability Analysis of dC Microgrid Clusters Based on Step-by-step System Matrix Building Algorithm

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 900-912页

作者： K.Jithin N.Mayadevi R.Hari Kumar v.P.Mini the department of Electrical Engineering College of Engineering TrivandrumAPJ Abdul Kalam Technological University(APJAKTU)ThiruvananthapuramIndia

dC microgrids(dCMGs)are made up of a network of sources and loads that are connected by a number of power electronic converters(PECs).The increase in the number of these PECs instigates major concerns in system *** interconnecting the microgrids to form a cluster,the system stability must be *** paper proposes a novel stepby-step system matrix building(SMB)algorithm to update the system matrix of an existing dCMG cluster when a new microgrid is added to the cluster through a distribution *** stability of the individual dCMGs and the dCMG cluster is analyzed using the eigenvalue ***,the particle swarm optimization(PSO)algorithm is used to retune the controller gains if the newly formed cluster is not *** simulation of the dCMG cluster is carried out in MATLAB/Simulink environment to test the proposed *** results are also validated using the OP4510 real-time simulator(RTS).

关键词： Converter dC microgrid cluster eigenvalue interconnection particle swarm optimization system stability system matrix

Performance analysis of deep borehole heat exchangers for decarbonization of heating systems

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deep Underground Science and Engineering 2024年第3期3卷 349-357页

作者： Andreas E.d.Lund department of Electrical Engineering and Automation Aalto UniversityEspooFinland

Meeting the climate change mitigation targets will require a substantial shift from fossil to clean fuels in the heating *** pumps with deep borehole exchangers are a promising solution to reduce *** the thermal behavior of deep borehole exchangers(dBHEs)ranging from 1 to 2 km was analyzed for various heat flow profiles.A strong correlation between thermal energy extraction and power output from dBHEs was found,also influenced by the heating profile *** operating time over the year typically resulted in higher energy production,while shorter one yielded higher average thermal power output,highlighting the importance of the choice of heating strategy and system design for optimal performance of *** breaks in operation for regenerating the borehole,for example,with waste heat,proved to be favorable for the performance yielding an overall heat output close to the same as with continuous extraction of *** results demonstrate the usefulness of deep boreholes for dense urban areas with less available *** the heat production from a single dBHE in Finnish conditions ranges from half up to even a few GWh a year,the technology is best suitable for larger heat loads.

关键词： clean energy deep borehole exchangers energy transition geothermal heat ground-coupled heat pump

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A perspective on greenhouse gas emission studies integrating arbuscular mycorrhiza

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Pedosphere 2024年第3期34卷 525-529页

作者： Stavros d.vERESOGLOU Junjiang CHEN State Key Laboratory of Biocontrol School of EcologySun Yat-sen UniversityShenzhen 518107(China)

Climate change is a global *** is only possible to pace down global change through addressing the triggers of it,greenhouse gas *** commendable progress,we think that there is plenty of room to further make the studies addressing global change realistic,through integrating into them biotic *** make a case for this statement through a bibliometrics analysis on agricultural studies exploring greenhouse gas emissions that consider arbuscular *** show that even though mycorrhizal studies account right now for a small fraction of the agricultural literature,they get cited more *** further demonstrate that mycorrhizal studies are typically more descriptive in their nature,which we support through comparing the keywords they *** subsequently use the opportunity to identify shortcomings and opportunities to further integrate mycorrhiza into agricultural studies assaying greenhouse gas *** finally make a call to better integrate arbuscular mycorrhiza into global change studies.

关键词： bibliometric analysis biochemical models global change biology Glomeromycota sustainable agricultural intensification