检索结果-南通市图书馆

Numerical investigation on the mechanism of impeller hub corner separation flow and induced energy loss in the bulb tubular pump

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 Hydrodynamics 2023年第2期35卷 252-267页

作者： Long-yue Sun Qiang Pan De-sheng Zhang rui-jie Zhao b.P.m.(bart)van Esch Research Center of Fluid machinery Engineering and Technology Jiangsu UniversityZhenjiang212013China Wenling Fluid machinery Technology Institute of Jiangsu University Wenling317525China Department of mechanical Engineering Eindhoven University of TechnologyEindhovenThe Netherlands Shimge Pump Industry(Zhejiang)Co. Ltd.Wenling317525China

Impeller hub corner separation flow(IHCS)has a significant influence on energy conversion of the bulb tubular pump,and its unsteady characteristics are investigated with CFD-based *** generation mechanism and power loss characteristics of IHCS are investigated by the entropy production method and pressure fluctuation *** main cause can be attributed to the large transverse pressure gradient near the hub at the trailing edge of the impeller,which is aggravated by the circumferential movement trend and the diffuser reverse flow,while the IHCS is significantly weakened with increased flow *** undesirable flow behavior is more likely to cause a significant increase in energy loss near the hub region compared to that in the rim *** relative vortex stretching induced by the velocity gradient is the main cause of the horn-like vortex(HLV),and its intensity and resulting energy loss tend to decrease along the vortex *** HLV changes the dominant frequency of the pressure fluctuations in the nearby flow field,the value of which increases from 1fr(the blade passing frequency)to 2fr with increased amplitude,mainly due to the lower pressure regions on the impeller suction surface(SS)and HLV vortex *** to the effect of rotor-stator interaction(RSI),the HLVs generated between two adjacent impeller blades are cut into several sections by the diffuser vanes and propagate and dissipate along the mainstream direction.

关键词： bulb tubular pump corner separation entropy production pressure fluctuation visualization analysis

Astronomical time scale for the lower Doushantuo Formation of early Ediacaran,South China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science bulletin 2018年第22期63卷 1485-1494页

作者： Yu Sui Chunju Huang rui Zhang Zhixiang Wang James Ogg David b.Kemp State Key Laboratory of biogeology and Environmental Geology School of Earth SciencesChina University of GeosciencesWuhan 430074China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059China Department of Earth Atmospheric and Planetary SciencesPurdue UniversityWest LafayetteIN 47907USA School of Geosciences University of AberdeenAberdeenScotland AB243UEUK

Nearly 90% of the Ediacaran Period(635–541 ma) of the Neoproterozoic is represented by the Doushantuo Formation(DST Fm) in South *** lowest member I is a 3.7 m-thick cap carbonate deposited at the termination of the Cryogenian marinoan *** DST Fm consists of alternating organic-rich black shale and thinly bedded dolostone, and it contains some of the oldest records of multicellular life and three pronounced negative carbon isotope *** Jiulongwan(JLW) section is a well-studied reference section for these Ediacaran *** analysis of geochemical data through the lower DST Fm(22.3 m) shows 27 predominant ～90 cm sedimentary cycles that correspond to 405-ka long eccentricity *** power spectra of the 405-ka tuned Ca and Fe/Ti series show significant peaks at ～1.2-ma, 405-ka, 133-ka, 128-ka, 100-ka, 82-ka, ～31-ka and 29-ka periods, respectively.A 11.16 malong astronomical time scale has been constructed for the lower DST Fm and provide a duration of 1.6 ma for the cap carbonate(member Ⅰ) based on the 405-ka long eccentricity cycle *** the U-Pb age of 635.2 ± 0.6 ma for the volcanic ash bed at the member Ⅰ/Ⅱboundary, we proposed a 636.8 ma age for the base of the DST *** ages and astronomical timescale provide important new constraints on the subdivision of Ediacaran strata, and have implications for understanding the character of the first negative δ^(13)C excursion(EN1).Orbital forcing may have been played an important role for the climate changes and the evolution of Ediacaran multi-cellular life and the carbon cycle variations.

关键词： Ediacaran Doushantuo Formation Astronomical time scale Orbital forcing Jiulongwan section

Constraining the non-Einsteinian polarizations of gravitational waves by pulsar timing array

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,mechanics & Astronomy) 2019年第7期62卷 63-75页

作者： rui Niu Wen Zhao CAS Key Laboratory for Researches in Galaxies and Cosmology Department of Astronomy University of Science and Technology of China School of Astronomy and Space Science University of Science and Technology of China

Pulsar timing array(PTA) provides an excellent opportunity to detect the gravitational waves(GWs) in nanoHertz frequency *** particular, due to the larger number of "arms" in PTA, it can be used to test gravity by probing the non-Einsteinian polarization modes of GWs, including two spin-1 shear modes labeled by "sn" and "se", the spin-0 transverse mode labeled by "b" and the longitudinal mode labeled by "l". In this paper, we investigate the capabilities of the current and potential future PTAs, which are quantified by the constraints on the amplitudes parameters(c_b, c_(sn), c_(se), c_l), by observing an individual supermassive black hole binary in Virgo cluster. We find that for binary with total mass m_c= 8.77 × 10~8 m_⊙ and GW frequency f = 10^(-9) Hz, the PTA at current level can detect these GW modes if c_b> 0.00106, c_l> 0.00217, c_(se)> 0.00271, c_(sn)> 0.00141, which will be improved by about two orders if considering the potential PTA in SKA era. Interesting enough, due to effects of the geometrical factors, we find that in SKA era, the constraints on the l, sn, se modes of GWs are purely dominated by several pulsars, instead of the full pulsars in PTA.

关键词： gravitational waves pulsar timing array

ISOPERImETRIC PRObLEmS OF THE CALCULUS OF VARIATIONS WITH FRACTIONAL DERIVATIVES

在线全文

学校读者我要写书评

暂无评论

Acta mathematica Scientia 2012年第2期32卷 619-630页

作者： Ricardo Almeida rui A.C.Ferreira Delfim F.m.Torres Center for Research and Development in mathematics and Applications Department of MathematicsUniversity of Aveiro3810-193 AveiroPortugal Department of mathematics Faculty of Engineering and Natural SciencesLusophone University of Humanities and Technologies1749-024 LisbonPortugal

In this article, we study isoperimetric problems of the calculus of variations with left and right Riemann-Liouville fractional derivatives. both situations when the lower bound of the variational integrals coincide a... 详细信息

关键词： Calculus of variations fractional derivatives isoperimetric problems

Harnessing memory adaptive regulatory T cells to control autoimmunity in type 1 diabetes

在线全文

学校读者我要写书评

暂无评论

Journal of molecular Cell biology 2012年第1期4卷 38-47页

作者： Cheng-rui Li bas J.G.baaten Linda m.bradley Infectious and Inflammatory Disease Center Sanford-Burnham Medical Research Institute10901 North Torrey Pines RoadLa JollaCA 92037USA

Type 1 diabetes(T1D)results from autoimmune destruction of insulin-producing b-cells in the pancreatic *** is an immediate need to restore both b-cell function and immune tolerance to control disease progression and ultimately cure ***,there is no effective treatment strategy to restore glucose regulation in patients with ***3-expressing CD4^(+) regulatory T cells(Tregs)are potential candidates to control autoimmunity because they play a central role in maintaining ***,deficiencies in either naturally occurring Tregs(nTregs)themselves and/or their ability to control pathogenic effector T cells have been associated with ***,we hypothesize that nTregs can be replaced by FoxP3^(+) adaptive Tregs(aTregs),which are uniquely equipped to combat autoreactivity in *** nTregs,aTregs are stable and provide long-lived *** this review,we summarize the current understanding of aTregs and their potential for use as an immunological intervention to treat T1D.

关键词： type 1 diabetes adaptive regulatory T cells autoimmunity immunotherapy

比较饮食摄取l-卡尼汀和dl-卡尼汀对氨中毒和肝代谢的作用(英文)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2001年第4期22卷 19-24页

作者： Vilma A F G GAZOLA,Gisele LOPES,Rose m m DIAS,rui CURI,Roberto b bAZOTTE State University of maring maring PR 87020-900 brazil CNPq Fellowship Undergraduate student University of Sao Paulo Sao Paulo SP 05508-900 brazil State University of maring maring PR 87020-900 brazil

AIm: To compare the effects of chronic supplementationwith l-carnitine （LCT） and dl-carnitine （DLC） on am-monia toxicity and hepatic metabolism. mETHODS:Three groups of male adult rats were studied: 1) supple-mented with LCT (1.2 mmol·kg-1·d-1), 2) supple-mented with DLC (1.2 mmol·kg-1·d-1), and 3) con-trol froup （COG） not supplemented. RESULTS: Thetreatment with LCT decreased the toxicity to ***, the supplementation with DLC did not showany significant effect. In contrast, the effects of thesupplementation with LCT and DLC on hepaticmetabolism were quite similar, ie, both groups showed:（a） intensified ammonia uptake and decreased urea pro-

关键词：卡尼汀肝代谢糖原异生氨

AbA signaling prevents phosphodegradation of the SR45 splicing factor to alleviate inhibition of early seedling development in Arabidopsis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Plant Communications 2023年第2期4卷 272-285页

作者： rui Albuquerque-martins Dora Szakonyi James Rowe Alexander m.Jones Paula Duque Instituto Gulbenkian de Ciencia 2780-156 OeirasPortugal Sainsbury Laboratory University of CambridgeCambridge B21LRUK

Serine/arginine-rich(SR)proteins are conserved splicing regulators that play important roles in plant stress responses,namely those mediated by the abscisic acid(AbA)*** Arabidopsis thaliana SR-like protein SR45 is a described negative regulator of the AbA pathway during early seedling *** the inhibition of growth by AbA signaling is counteracted to maintain plant development under stress conditions remains largely ***,we show that SR45 overexpression reduces Arabidopsis sensitivity to AbA during early seedling *** and confocal microscopy analyses of transgenic plants expressing fluorescently tagged SR45 revealed that exposure to AbA dephosphorylates the protein at multiple amino acid residues and leads to its accumulation,due to SR45 stabilization via reduced ubiquitination and proteasomal *** phosphomutant and phosphomimetic transgenic Arabidopsis lines,we demonstrate the functional relevance of AbA-mediated dephosphorylation of a single SR45 residue,T264,in antagonizing SR45 ubiquitination and degradation to promote its function as a repressor of seedling AbA *** results reveal a mechanism that negatively autoregulates AbA signaling and allows early plant growth under stress via posttranslational control of the SR45 splicing factor.

关键词： abscisic acid alternative splicing Arabidopsis thaliana protein phosphorylation SR proteins

Percutaneous radiofrequency ablation for early hepatocellular carcinoma: Risk factors for survival

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第6期20卷 1585-1593页

作者： Luciana Kikuchi marcos menezes Aline L Chagas Claudia m Tani Regiane SSm Alencar marcio A Diniz Venncio AF Alves Luiz Augusto Carneiro D’Albuquerque Flair José carrilho So Paulo Clínicas Liver Cancer Group Instituto do Cancer do Estado de So Paulo Hospital das Clínicas Department of Gastroenterology University of So Paulo School of Medicine So Paulo Clínicas Liver Cancer Group Instituto do Cancer do Estado de So Paulo Hospital das Clínicas Department of Radiology University of So Paulo School of Medicine So Paulo Clínicas Liver Cancer Group Instituto do Cancer do Estado de So Paulo Hospital das Clínicas Department of Pathology University of So Paulo School of Medicine

AIm: To evaluate outcomes of radiofrequency ablation (RFA) therapy for early hepatocellular carcinoma (HCC) and identify survival- and recurrence-related factors.

关键词： Hepatocellular carcinoma Radiofrequency ablation Overall survival Disease-free survival

Individual aircraft life monitoring： An engineering approach for fatigue damage evaluation

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 Aeronautics 2018年第4期31卷 727-739页

作者： rui JIAO Xiaofan HE Yuhai LI School of Aeronautic Science and Engineering Beihang University Beijing 100083 China A viation Industry Corporation of China Beijng 100022 China

Individual aircraft life monitoring is required to ensure safety and economy of aircraft structure, and fatigue damage evaluation based on collected operational data of aircraft is an integral part of it. To improve the accuracy and facilitate the application, this paper proposes an engineering approach to evaluate fatigue damage and predict fatigue life for critical structures in fatigue monitoring. In this approach, traditional nominal stress method is applied to back calculate the S-N curve parameters of the realistic structure details based on full-scale fatigue test data. Then the S-N curve and miner＇s rule are adopted in damage estimation and fatigue life analysis for critical locations under individual load spectra. The relationship between relative small crack length and fatigue life can also be predicted with this approach. Specimens of 7 b04-T74 aluminum alloy and TA15 m titanium alloy are fatigue tested under two types of load spectra, and there is a good agreement between the experimental results and analysis results. Furthermore, the issue concerning scatter factor in individual aircraft damage estimation is also discussed.

关键词： Fatigue damage Fatigue monitoring Fatigue test Scatter factor S-N curve