检索结果-南通市图书馆

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

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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)

维普期刊数据库

Is Deep time Geology Scientific?

在线全文

学校读者我要写书评

暂无评论

Journal of Earth Science 2024年第2期35卷 700-703页

作者： t.Mark Harrison Department of Earth Planetary and Space SciencesUniversity of CaliforniaLos Angeles90095USA

We all know what car mechanics *** maintain and repair our automobiles according to established engineering *** all know what physicians *** maintain and repair our bodies according to established medical *** what is it that I do as a scientist?Indeed,am I a scientist?the answer to these questions depends on what we meant by“science”.

关键词： maintain Deep repair

维普期刊数据库

An Ethical Framework for the Use of AI by Revenue Authorities

在线全文

学校读者我要写书评

暂无评论

Belt and Road Initiative tax Journal 2024年第1期 41-51页

作者： Grant Wardell-johnson Conrad turley KPMG

the use of Al may give rise to substantial benefits but also significant risks for revenue *** paper provides a brief outline of the perceived strengths and weaknesses of Al and potential use of Al in tax *** include the use of Al in risk assessment such as the selection of taxpayers for review or audit,the detection of fraud,nearest neighbour guidance,predictive analysis,anticipating changes in behaviours,improving revenue authorities' internal efficiency including transfer pricing benchmarking,and providing support and guidance to taxpayers through *** authorities are strong candidates for the use of Al given that data is central to what they *** paper postulates more than 20principles which could form the basis of an ethical framework for revenue authorities including policies on transparency,communication,traceability,explainability,human supervision,processes for the rectification of errors,data protection,privacy and *** believe that the adoption of these policies will reduce risks to revenue authorities and build trust in tax *** also believe that sharing best practices amongst revenue authorities should be a clear BRItACOM initiative consistent with its aims and objectives.

关键词：

单期相双能量Ct能可靠地诊断肾上腺腺瘤吗?

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2014年第5期 496-496页

作者： A.Helck N.Hummel F.G.Meinel t.johnson K.Nikolaou A.Graser 唐春香 Institute for Clinical Radiology University of MunichGrosshadern CampusMarchioninistr.1581377MunichGermany

摘要目的评估基于单期相双能量 Ct 的衰减值测量能否可靠地鉴别含脂质丰富的肾上腺腺瘤与肾上腺恶性病变。方法回顾性纳入 51 例有肾上腺肿块并接受双能量 Ct 增强

关键词：肾上腺腺瘤脂质虚拟平扫脂类双能量 Ct

Unsteady MHD Casson Nanofluid Flow Past an Exponentially Accelerated Vertical Plate:An Analytical Strategy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第7期140卷 431-460页

作者： t.Aghalya R.tamizharasi Department of Mathematics School of Advanced SciencesVellore Institute of TechnologyVelloreTamilnadu632014India

In this study,the characteristics of heat transfer on an unsteady magnetohydrodynamic(MHD)Casson nanofluid over an exponentially accelerated vertical porous plate with rotating effects were *** flow was driven by the combined effects of the magnetic field,heat radiation,heat source/sink and chemical *** oxide(CuO)and titanium oxide(tiO2)are acknowledged as nanoparticle *** nondimensional governing equations were subjected to the Laplace transformation technique to derive closed-form *** representations are provided to analyze how changes in physical parameters,such as the magnetic field,heat radiation,heat source/sink and chemical reaction,affect the velocity,temperature and concentration *** computed values of skin friction,heat and mass transfer rates at the surface were tabulated for various sets of input *** is perceived that there is a drop in temperature due to the rise in the heat source/sink and the Prandtl *** should be noted that a boost in the thermal radiation parameter prompts an increase in *** increase in the Prandtl number,heat source/sink parameter,time and a decrease in the thermal radiation parameter result in an increase in theNusselt *** computed values of the skin friction,heat andmass transfer rates at the surface were tabulated for various values of the flow *** present results were compared with those of previously published studies andwere found to be in excellent *** research has practical applications in areas such as drug delivery,thermal medicine and cancer treatment.

关键词： thermal radiation radiative flux nanofluid copper oxide titanium oxide accelerated plate

Eliciting CD4-mimicking broadly neutralizing antibodies:new avenues towards the rational design of an HIV vaccine

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Signal transduction and targeted therapy 2024年第3期9卷 836-838页

作者： Frauke Muecksch Oliver t.Fackler Department of Infectious Diseases Heidelberg UniversityMedical Faculty HeidelbergVirologyCenter for Integrative Infectious Disease Research(CIID)HeidelbergGermany Chica and Heinz Schaller(CHS)Research Group Department of Infectious DiseasesVirologyUniversity Hospital HeidelbergHeidelbergGermany Department of Infectious Diseases Heidelberg UniversityMedical Faculty HeidelbergIntegrative VirologyCenter for Integrative Infectious Disease Research(CIID)HeidelbergGermany German Centre for Infection Research(DZIF) Partner Site HeidelbergHeidelbergGermany

In a study recently published in Cell,Saunders et *** that a new anti-HIV vaccine triggers antibody responses resembling CD4-binding site broadly neutralizing antibody precursors in rhesus macaques.1 this study provid... 详细信息

关键词： al. vaccine rational

Recent Advances in Catalytic Carbonylation Reactions in Alternative Reaction Media

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第4期42卷 406-429页

作者： Csaba Árvai László t.Mika Department of Chemical and Environmental Process Engineering Faculty of Chemical Technology and BiotechnologyBudapest University of Technology and EconomicsMűegyetem rkp.3H-1111 BudapestHungary

Since the discovery of the hydroformylation(oxo-synthesis or Roelen reaction)and the Reppe-reaction,the transition metal-catalyzed carbonylation reactions,providing versatile,facile,and even atom-economic methods for the selective incorporation of C=O functionality to various skeletons,have gained tremendous importance in synthetic organic chemistry from laboratories to industrial *** carbonylation of carbon-carbon multiple bonds,aromatic halides,triflates,etc.,in the presence of various nucleophiles has led the way to produce aldehydes,carboxylic acids,esters,amides,etc.,in the fine chemical ***,these protocols usually proceed in conventional,fossil-based,and usually toxic reaction ***,several attempts have been directed to developing efficient carbonylation methods in alternative,less harmful,non-fossil-based and even in renewable reaction *** this review,we overview the recent applications of alternative solvents such as water,biomass-based alcohols,γ-valerolactone(GVL),2-methyltetrahydrofuran(2-MetHF),ionic liquids(ILs),deep eutectic solvents(DES),alkyl levulinates,limonene,α-pinene,and dimethyl carbonate as well as fluorous media to improve efficiency,safety and environmentally benign nature of carbonylation protocols.

关键词： Carbonylation Catalysis Solvents Green chemistry Carbon monoxide transition metals Homogeneous catalysis Palladium

EP Aquarii:A New Picture of the Circumstellar Envelope

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第3期24卷 83-105页

作者： Pham t.Nhung Do t.Hoai Pierre Darriulat Pham tuan-Anh Pham N.Diep Nguyen B.Ngoc tran t.thai Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa Noivietnam

New analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented,which complete a previously published analysis and offer a different interpretation of the morpho-kinematics of the circumstellar *** birth of the equatorial density enhancement(EDE)is shown to occur very close to the star where evidence for rotation has been *** to the star and where outflows have been observed:their interaction with the gas of the nascent EDE is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8 to 10 km s^(-1) on the polar symmetry axis to~2 km s^(-1) at the *** implies complex morpho-kinematics:making reliable interpretations with reasonable confidence is *** particular,it questions an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of -0″4 from its *** proposes instead an interpretation in terms of a standard mass ejection associated with a shock wave leaving a void of emission in its *** Doppler velocity wings are seen to consist of two components,the upper velocity end of the global wind,reaching above±12 km s^(-1),and an effective line broadening,confined within 200 mas from the center of the star,reaching above±20 km s^(-1) and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell partition.

关键词： stars AGB and post-AGB-(stars) circumstellar matter-radio lines stars

维普期刊数据库

A 63-Year-Old Male with D-transposition of the Great Arteries Who Had an Early Form of the Arterial Switch Operation

在线全文

学校读者我要写书评

暂无评论

Congenital Heart Disease 2024年第1期19卷 65-68页

作者： Michael A.Rebolledo Jane S.Yao Jason N.johnson Umar S.Boston Benjamin R.Waller III Division of Pediatric Cardiology Department of PediatricsThe University of Tennessee Health Science CenterThe Heart InstituteLe Bonheur Children’s HospitalMemphisUSA College of Medicine The University of Tennessee Health ScienceMemphisUSA Division of Pediatric Cardiothoracic Surgery Department of SurgeryThe University of Tennessee Health Science CenterHeart InstituteLe Bonheur Children’s HospitalMemphisUSA

We describe a 63-year-old male who appears to have undergone an early form of the arterial switch operation for D-transposition of the great arteries performed in the *** review the clinical and imaging data that support our *** had a diagnostic cardiac catheterization which demonstrated severe pulmonary hypertension responsive to epoprostenol and *** case may represent one example of the experimental surgical work done prior to *** Jatene’s description of theﬁrst successful arterial switch performed in 1975.

关键词： Adult congenital heart disease arterial switch operation great vessel anomaly imaging(all modalities)