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)

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

EVOLUtION AND INtERACtION OFδ-WAVES IN tHE ZERO-PRESSURE GAS DYNAMICS SYStEM

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2024年第5期44卷 1801-1836页

作者： Abhishek DAS K.t.JOSEPH Centre for Data Science Institute of Technical Education and Research(ITER)Siksha‘O’Anusandhan(Deemed to be University)BhubaneswarOdisha751030India Centre for Applicable Mathematics Tata Institute of Fundamental ResearchSharada NagarBangalore560065KarnatakaIndia

Evolution and interaction of plane waves of the multidimensional zero-pressure gas dynamics system leads to the study of the corresponding one dimensional *** this paper,we study the initial value problem for one dimensional zero-pressure gas dynamics *** the first equation is the Burgers equation and the second one is the continuity *** consider the solution with initial data in the space of bounded Borel *** we prove a general existence result in the algebra of generalized functions of *** we study in detail special solutions withδ-measures as initial *** study interaction of waves originating from initial data concentrated on two point sources and interaction with classical shock/rarefaction *** gives an understanding of plane-wave interactions in the multidimensional *** use the vanishing viscosity method in our analysis as this gives the physical solution.

关键词： zero-pressure gas dynamics delta-waves interaction of waves

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

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

RARRES2's impact on lipid metabolism in triplenegative breast cancer:a pathway to brain metastasis

在线全文

学校读者我要写书评

暂无评论

Military Medical Research 2024年第2期11卷 311-312页

作者： Quazi t.H.Shubhra Institute of Chemistry University of Silesia in Katowice41‑500 ChorzowPoland Department of Neurosurgery Renmin Hospital of Wuhan UniversityWuhan 430060China

Breast cancer brain metastasis(BCBrM)is a crucial and hard area of research which guarantees an urgent need to understand the underlying molecular mechanisms.A recent study by Li et al.[1]published in Military Medical Research investigated the role of retinoic acid receptor responder 2(RARRES2)in regulating lipid metabolism in BCBrM,highlighting the clinical relevance of alterations in lipid metabolites,such as phosphatidylcholine(PC)and triacylglycerols(tAGs),by RARRES2 through the modulation of phosphatase and tensin homologue(PtEN)-mammalian target of rapamycin(mtOR)-sterol regulatory element-binding protein 1(SREBP1)signaling *** commentary aims to elaborate on the key findings and their relevance to the field.

关键词： Retinoic acid receptor responder 2(RARRES2) Lipid metabolism Cancer PtEN-mtOR-SREBP1 signaling Metabolic reprogramming Brain metastasis

Basis for the diversity and extent in loss of digestible nutrients created by dietary phytin: Emphasis on fowl and swine

在线全文

学校读者我要写书评

暂无评论

Animal Nutrition 2024年第1期16卷 422-428页

作者： Edwin t.Moran Michael R.Bedford Poultry Science Department Auburn University AB Vista Woodstock Court Blenheim Road

Phytin is the Ca2+-Mg2+-K+salt of phytic acid that is created and deposited in the aleurone layer and/or germ of grains and legumes. Its high presence in feedstuffs for fowl and swine diets results in it being a universal and significant impediment to optimum performance. Phytin impairs gastrointestinal recovery of a wide array of nutrients, the effect varying with the nutrient concerned. On exposure to low pH during gastric digestion, phytin dissociates into phytic acid and solubilized Ca2+. Even at low gastric pH,phytic acid is negatively charged which forms the basis of its anti-nutritive behavior. Pepsinogen has extensive basic amino acids on its activation peptide that are presented as cations at low pH which are targeted by pepsin for activation. Partially crystalized Ca2+near the enzyme?s active site further stabilizes its newly formed structure. thus, phytic acid appears to interfere with gastric digestion by several mechanisms; interfering with pepsinogen activation by binding to the polypeptide?s basic amino acids;coordinating free Ca2+, destabilizing pepsin; binding some dietary proteins directly, further compromising gastric proteolysis. Upon digesta attaining neutrality in the duodenum, Ca2+and other cations rebind with accessible anions, phytic acid being a significant contender. Phytate not only binds free cations but can also strip them from enzymes(e.g. Ca2+, Zn2+) which reduces their structural resistance to autolysis and ability as co-factors(e.g. Zn2+) to increase enzyme activity. Goblet cells initially employ Ca2+as an electronic shield between mucin layers enabling granule formation and cell storage. After mucin granule release, Ca2+is progressively displaced by Na+to free the viscous mucins enabling its translocation. Mucin entangles with the glycocalyx of adjacent enterocytes thereby constructing the unstirred water layer（USWL）. Excessive removal of Ca2+from mucin by phytic acid increases its fluidity facilitating its loss from the USWL with

关键词： Digestive enzyme Calcium Endogenous protein Mucin Phytin