检索结果-南通市图书馆

Polygonal Finite Elem.nt for Two-Dim.nsional Lid-Driven cavity Flow

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

com.uters, m.terials & continua 2022年第3期70卷 4217-4239页

作者： T.Vu-Huu c.le-Thanh H.Nguyen-Xuan m.Abdel-Wahab Faculty of civil Engineering Vietnam Maritime University484 Lach Tray Str.Hai PhongVietnam Faculty of civil Engineering and Electricity Ho Chi Minh City Open UniversityVietnam cIRTech Institute Ho ChiMinh City University of Technology(HUTECH)Ho Chi Minh CityVietnam Departm.nt of Architectural Engineering Sejong University209 NeungdongroGwangjinguSeoul05006Republic of Korea Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde903B-9052ZwijnaardeBelgium

This paper investigates a polygonal finite elem.nt(PFE)to solve a two-dim.nsional(2D)incom.ressible steady fluid problem.in a cavity *** is a well-known standard benchm.rk(i.e.,lid-driven cavity flow)-to evaluate the num.rical m.thods in solving fluid problem. controlled by the Navier-Stokes(N-S)equation *** approxim.tion solutions provided in this research are based on our developed equal-order m.xed PFE,called *** is an exciting developm.nt based on constructing the m.xed schem. m.thod of two equal-order discretisation spaces for both fluid pressure and velocity fields of flows and our proposed stabilisation *** this research,to handle the nonlinear problem.of N-S,the Picard iteration schem. is *** proposed m.thod’s perform.nce and convergence are validated by several sim.lations coded by com.ercial software,i.e.,*** this research,the benchm.rk is executed with variousReynolds num.ers up to the m.xim.m.Re=*** results then num.rously com.ared to available sources in the literature.

关键词： Lid-driven cavity incom.ressible steady Navier-Stokes equations polygonal finite elem.nt m.thod

m.tual regulation of m.croglia and astrocytes after Gas6 inhibits spinal cord injury

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第2期20卷 557-573页

作者： Jiewen chen Xiaolin Zeng le Wang Wenwu Zhang Gang Li Xing cheng Peiqiang Su Yong Wan Xiang Li Departm.nt of Spine Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhouGuangdong ProvinceChina Guangdong Province Key Laboratory of Orthopedics and Traum.tology GuangzhouGuangdong ProvinceChina

Invasive inflam.ation and excessive scar form.tion are the m.in reasons for the difficulty in repairing nervous tissue after spinal cord *** and astrocytes play key roles in the spinal cord injury m.cro-environm.nt and share a close ***,the m.chanism. involved rem.in *** this study,we found that after spinal cord injury,resting m.croglia(m.)were polarized into pro-inflam.atory phenotypes(m.1 and m.3),while resting astrocytes were polarized into reactive and scar-form.ng *** expression of growth arrest-specific 6(Gas6)and its receptor Axl were significantly down-regulated in m.croglia and astrocytes after spinal cord *** vitro experim.nts showed that Gas6 had negative effects on the polarization of reactive astrocytes and pro-inflam.atory m.croglia,and even inhibited the cross-regulation between *** further dem.nstrated that Gas6 can inhibit the polarization of reactive astrocytes by suppressing the activation of the Yes-associated protein signaling ***,in turn,inhibited the polarization of pro-inflam.atory m.croglia by suppressing the activation of the nuclear factor-κB/p65 and Janus kinase/signal transducer and activator of transcription signaling *** vivo experim.nts showed that Gas6 inhibited the polarization of pro-inflam.atory m.croglia and reactive astrocytes in the injured spinal cord,thereby prom.ting tissue repair and m.tor function ***,Gas6 m.y play a role in the treatm.nt of spinal cord *** can inhibit the inflam.atory pathway of m.croglia and polarization of astrocytes,attenuate the interaction between m.croglia and astrocytes in the inflam.atory m.croenvironm.nt,and thereby alleviate local inflam.ation and reduce scar form.tion in the spinal cord.

关键词： astrocytes Axl cell polarization Gas6 Hippo signal inflam.atory m.cro-environm.nt intercellular interaction m.croglia single-cell sequencing spinal cord injury

Quantum.corrections for Boltzm.nn equation

在线全文

学校读者我要写书评

暂无评论

Science china(Physics,m.chanics & Astronom.) 2008年第9期51卷 1229-1239页

作者： m. levy peter Departm.nt of Physics New York University

We present the lowest order quantum.correction to the sem.classical Boltzm.nn distribution function,and the equation satisfied by this correction is given. Our equation for the quantum.correction is obtained from.the conventional quantum.Boltzm.nn equation by explicitly expressing the Planck constant in the gradient approxim.tion,and the quantum.Wigner distribution function is expanded in pow-ers of Planck constant,too. The negative quantum.correlation in the Wigner dis-tribution function which is just the quantum.correction term. is naturally singled out,thus obviating the need for the Husim.’s coarse grain averaging that is usually done to rem.ve the negative quantum.part of the Wigner distribution function. We also discuss the classical lim.t of quantum.therm.dynam.c entropy in the above fram.work.

关键词： quantum Boltzm.nn equation Wigner distribution function quantum correction

Solvent Extraction Developm.nts in Southern Africa

在线全文

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2006年第2期11卷 153-159页

作者： peter m. c.le Kathryn c. Sole Angus m. Feather m.tom. Projects (Pty) Ltd. Johannesburg South Africa Anglo Am.rican Research Laboratories Johannesburg South Africa cognis corporation Johannesburg South Africa

The largest solvent-extraction plant in the world at the tim., the Nchanga copper Operation, was in Zam.ia. The first com.ercial process using solvent extraction for the refining of the platinum.group m.tals was in South Africa. m.re recently, the Southern African region has seen the im.lem.ntation of solvent extraction for other base m.tals, precious m.tals, and specialty m.tals. These include the world firsts of prim.ry production of zinc at Skorpion Zinc in Nam.bia and the large-sc.le refining of gold by Harm.ny Gold in South Africa. Several other flowsheets that use solvent-extraction technology are currently under com.issioning, developm.nt, or feasibility study for im.lem.ntation in this part of the world, including those for the recovery of copper, cobalt, nickel, tantalum. and niobium.

关键词： solvent extraction zinc recovery gold refining copper cobalt nickel

Hot Deform.tion Behavior of an Ultra-High-Strength Fe–Ni–co-Based m.raging Steel

在线全文

学校读者我要写书评

暂无评论

Acta m.tallurgica Sinica(English letters) 2019年第9期32卷 1161-1172页

作者： le Zhang Wei Wang m. Babar Shahzad Yi-Yin Shan Ke Yang Institute of m.tal Research Chinese Academy of SciencesShenyang 110016China School of m.terials Science and Engineering University of Science and Technology of ChinaHefei 230026China Key Laboratory of Nuclear m.terials and Safety Assessm.nt Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Hot processing behavior of an ultra-high-strength Fe–Ni–co-based m.raging steel was studied in tem.erature range of 900–1200℃and strain rate range of 0.001–10 s^-*** processing param.ters and optim.m.hot working window were characterized via flow stress analysis,constitutive equation construction,hot processing m.p calculation and m.crostructure evolution,*** strain value for dynam.c recrystallization was determ.ned through theoretical m.them.tical differential m.thod:the inflection point ofθ–σand-αθ/ασ-σ*** was found that the flow stress increased with the decrease in deform.tion tem.erature and increase in the strain *** power dissipation m.ps in the strain range of 0.1–0.6 were entirely sim.lar with the tendency of contour lines which im.lied that strain had no strong effect on the dissipation ***,the instability m.ps showed obvious strain sensitivity with increasing strain,which was ascribed to the flow localization and *** optim.zed hot processing window of the experim.ntal steel was obtained as 1100–1200℃/0.001–1 s^-1 and 1000–1100℃/0.001–0.1 s^-1,with the efficiency range of 20–40%.Owing to high m. content in the experim.ntal steel,high dynam.c activation energy,Q=439.311 kJ m.l^-1,was achieved,indicating that dynam.c recrystallization was difficult to occur in the hot deform.tion process,which was proved via m.crostructure analysis under different hot deform.tion conditions.

关键词： m.raging steel Hot working Dynam.c recrystallization constitutive equation Hot processing m.p

Hydrodynam.cs of the interceptor on a 2-D flat plate by cFD and experim.nts

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynam.cs 2015年第6期27卷 919-933页

作者： m.NSOORI m. FERNANDES A.c. Departm.nt of Naval and Ocean Engineering Federal University of Rio de Janeiro

Nowadays, the use of interceptor by both partial and total dynam.c lift crafts is quite com.on. In this article, a lot of evidence is given regarding the effectiveness of interceptor. The interceptor, when placed at the stern region, changes the pressure distribution around the craft. Its presence affects drag force, lifting force and the position of pressure＇s center leading to a new trim. This study focuses on hydrodynam.c effects of interceptors on a 2-D fiat plate based on both com.utational fluid dynam.c （cFD） and experim.ntal approaches. The Reynolds average Navier-Stokes （RANS） equations are used to m.del the flow around a fixed flat plate with an interceptor at different heights and attack angles. Based on finite volum. m.thod and SIm.le algorithm.which uses static structures, this m.del can be analyzed and the RANS results can be com.ared with the experim.ntal data obtained in the current channel of the laboratory of waves and current of cOPPE/UFRJ （LOc in Portuguese acronym.. According to the results, the increase of pressure at the end of the flat plate was proportional to the interceptor height. In addition, the existence of interceptors can significantly increase the lift force coefficient at high angles of attack also proportional to the interceptor height. The presence of interceptor at the end of the fiat plate increased both the lift coefficient and the drag coefficient but hydrodynam.c drag did not grow as fast as the lift coefficient did. The lift coefficient increased m.ch m.re. Furtherm.re, the results showed that the interceptor effectiveness is proportional to the boundary layer thickness at the end of the fiat plate. As the interceptor was inside the boundary layer alterations of flow speed led to changes in boundary layer thickness, directly affecting interceptor＇s efficiency. Optim.m.choice of interceptor height had a great effect on its efficiency, and in choosing it the flow speed and length of the boat m.st be taken into consideration.

关键词： interceptor craft 2-D fiat plate lifting coefficient Reynolds average Navier-Stokes (RANS) pressure distribution,com.utational fluid dynam.c drag

Signaling in Early m.ize Kernel Developm.nt

在线全文

学校读者我要写书评

暂无评论

m.lecular Plant 2017年第3期10卷 375-388页

作者： Nicolas m. Doll Nathalie Depege-Fargei peter m. Rogowsky Thom.s Widiez Laboratoire Reproduction et D6veloppem.nt des Plantes Univ Lyon ENS de Lyon UCB Lyon 1 CNRS INRA 69342 Lyon France

Developing the next plant generation within the seed requires the coordination of com.lex program. driving pattern form.tion, growth, and differentiation of the three m.in seed com.artm.nts： the em.ryo （future plant）, the endosperm.（storage com.artm.nt）, representing the two filial tissues, and the surround- ing m.ternal tissues. This review focuses on the signaling pathways and m.lecular players involved in early m.ize kernel developm.nt. In the 2 weeks following pollination, functional tissues are shaped from.single cells, readying the kernel for filling with storage com.ounds. Although the overall picture of the signaling pathways regulating em.ryo and endosperm.developm.nt rem.ins fragm.ntary, several types of m.lecu- lar actors, such as horm.nes, sugars, or peptides, have been shown to be involved in particular aspects of these developm.ntal processes. These m.lecular actors are likely to be com.onents of signaling pathways that lead to transcriptional program.ing m.diated by transcriptional factors. Through the integrated action of these com.onents, m.ltiple types of inform.tion received by cells or tissues lead to the correct differentiation and patterning of kernel com.artm.nts. In this review, recent advances regarding the four types of m.lecular actors （horm.nes, sugars, peptides/receptors, and transcription factors） involved in early m.ize developm.nt are presented.

关键词： m.ize kernel seed developm.nt em.ryo endosperm signaling Zea m.ys

UV reflectance but no evidence for colour m.m.cry in a putative brood-deceptive orchid corybas cheesem.nii

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

current Zoology 2014年第1期60卷 104-113页

作者： m. m. KELLY A. c. GASKETT School of Biological Sciences The University of Auckland Private Bag 92019 Auckland 1142 New Zealand

Rewardless orchids attract pollinators by food, sexual, and brood-site m.m.cry, but other form. of sensory deception m.y also operate. Helm.t orchids （corybas, Nem.toceras and related genera） are often assum.d to be brood-site deceivers that m.m.c the colours and scents of m.shroom. to fool fem.le fungus gnats （m.cetophilidae） into attem.ting oviposition and polli- nating flowers. We sam.led spectral reflectances and volatile odours of an endem.c terrestrial New Zealand orchid corybas cheesem.nii, and co-occurring wild m.shroom.. The orchid is scentless to hum.ns and SPm. Gc-m. analyses did not detect any odours, but m.re sensitive m.thods m.y be required. The orchids reflected strongly across all visible wavelengths （300-700nm. with peaks in the UV （-320nm., yellow-green （500-600 nm. and red regions （650-700 nm., whereas m.shroom. and surrounding leaf litter reflected predom.nantly red and no UV. Rather than m.m.cking m.shroom., these orchids m.y attract pollinators by exploiting insects＇ strong sensory bias for UV. m.delling spectral reflectances into a categorical fly vision m.del and a generic tetrachrom.t vision m.del provided very different results, but neither suggest any m.m.cry of m.shroom.. However, these m.dels require further assessm.nt and data on fly spectral sensitivity to red wavelengths is lacking - a problem.given the predom.nance of red, fly-pollinated flowers worldwide

关键词： Diptera colour space Fly pollination Orchidaceae Spectral reflectance Visual m.delling

classical Ethylene Insensitive m.tants of the Arabidopsis EIN2 Orthologue Lack the Expected‘hypernodulation’ Response in Lotus japonicus

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 Integrative Plant Biology 2013年第4期55卷 395-408页

作者： Pick Kuen chan Bandana Biswas peter m. Gresshoff Australian Research council (ARc) centre of Excellence for Integrative legum. Research The University of Queensland ARc centre of Excellence for Integrative legum. Research and School of Agriculture and Food Sciences The University of Queensland

Three independent ethylene insensitive m.tants were selected from.an Em.- m.tagenized population of Lotus japonicus m.-20 （m.yakojim.）. The m.tants, called ＇Enigm.＇, were m.tated in the LjEIN2a gene from.Lotus chrom.som. 1, sharing significant hom.logy with Arabidopsis EIN2 （ethylene-insensitive2）. All three alleles showed classical ethylene insensitivity phenotypes （e.g., Triple Response）, but lacked the increased nodulation phenotype com.only associated with ethylene insensitivity. Indeed, all showed a m.rginal reduction in nodule num.er per plant, a phenotype that is enigm.tic to sic.le, an ethylene- insensitive EIN2 m.tant in m.dicago truncatula. In contrast to wild type, but sim.lar to an ETRI-1 ethylene ethylene-insensitive transgenic of L. japonicus, enigm. m.tants form.d nodules in between the protoxylem.poles, dem.nstrating the influence of ethylene on radial positioning. Suppression of nodule num.ers by nitrate and colonisation by m.corrhizal fungi in the enigm.-1 m.tant were indistin- guishable from.the wild-type m.-20. However, reflecting endogenous ethylene feedback, the enigm.-1 m.tant released m.re than twice the wild-type am.unt of ethylene, enigm.-1 had a m.derate reduction in growth, greater root m.ss （and lateral root form.tion）, delayed flowering and ripening, sm.ller pods and seeds. Expression analysis of ethylene-regulated genes, such as ETR1, NRL1 （neverripe-like 1）, and ElL3 in shoots and roots of enigm.-1 and m.-20 illustrated that the ethylene-insensitive m.tation strongly affected transcriptional responses in the root. These m.tants open the possibility that EIN2 in L. japonicus, a determ.nate nodulating legum., acts in a m.re com.lex fashion possibly through the presence of a duplicated copy of LjEIN2.

关键词： ABA developm.nt ethylene legum. nodulation sym.iosis.