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Hybrid LES/RANS Sim.lations of Com.ressible Flow in a Linear Cascade of Flat Blade Profiles

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Journal of Therm.l Science 2024年第5期33卷 1839-1850页

作者： Jarom.r PRIHODA Petr STRAKA david SIm.RDA Petr SIDLOF Jan LEPICOVSKY Institute of Therm.m.chanics of the Czech Academ. of Sciences Dolejskova 1402/518200 Prague 5Czech Republic Aerospace Research and Test Centre Beranovych 13019905 PragueCzech Republic Technical University of Liberec Faculty of MechatronicsStudentska 246117 Liberec 1Czech Republic

The paper reports on 3D num.rical sim.lations of unsteady com.ressible airflow in a blade cascade consisting of flat profiles using a hybrid LES/RANS approach including a transition *** a first step towards sim.lation of blade flutter in turbom.chinery,various incidence angle offsets of the m.ddle blade were *** sim.lations were run for the flow regim. characterized by outlet isentropic m.ch num.er m.(is)=0.5and zero *** results of the LES/RANS sim.lations(pressure and m.ch num.er distributions)were com.ared to a baseline RANS m.del,and to experim.ntal data m.asured in a high-speed wind *** num.rical results show that both m.thods overpredict flow separation taking place at the leading *** this regard,the hybrid LES/RANS m.thod does not provide superior results com.ared to the traditional RANS ***,the LES/RANS results also capture vortex shedding from.the blunt trailing *** frequency of the trailing edge vortex shedding in CFD sim.lations m.tches perfectly the spectral peak recorded during wind tunnel m.asurem.nts.

关键词： num.rical sim.lation blade cascade hybrid LES/RANS

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青藏高原地表变暗与北极气候变化间的共振

Science Bulletin 2024年第3期69卷 367-374页

作者：汤舒畅朴世龙 david m.Holland 阚飞汪涛姚檀栋李熙晨 Sino-French Institute for Earth System.Science College of Urban and Environmental SciencesPeking UniversityBeijing 100871China State Key Laboratory of Tibetan Plateau Earth System Resources and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100085China Courant Institute of m.them.tical Sciences New York UniversityNew YorkNY 0711USA Institute of Atm.spheric Physics Chinese Academy of SciencesBeijing 100029China

The Tibetan Plateau(TP)exerts a profound influence on global clim.te over m.llion-year tim.scales due to its past ***,whether the ongoing clim.te changes over the TP,particularly the persistent reduction in its local albedo(referred to as“TP surface darkening”),can exert global im.acts rem.ins *** this study,a state-of-the-art coupled land–atm.sphere global clim.te m.del has been em.loyed to scrutinize the im.act of TP darkening on polar clim.te *** indicate that the projected TP darkening has the potential to generate a stationary Rossby wave train,thereby m.dulating the atm.spheric circulation in the high-latitudes of the Northern Hem.sphere and instigating a dipole-like surface air tem.erature anom.ly pattern around the Arctic *** additional experim.nt suggests that the projected Arctic warm.ng m.y in return warm.the TP,thus form.ng a bi-directional linkage between these two clim.te *** their association with vast ice reservoirs,the elucidation of this m.chanism.in our study is crucial in advancing our com.rehension of Earth system.clim.te projections.

关键词： Tibetan Plateau High-latitude Northern Hem.sphere Arctic Clim.te change Albedo Surface darkening

Navigating the controversy regarding antibiotic prophylaxis in acute variceal bleeding

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World Journal of Gastroenterology 2024年第18期30卷 2485-2487页

作者： david Aguirre-Villarreal Ignacio García-Juárez Departm.nt of Gastroenterology and Liver Transplant Unit Instituto Nacional de Ciencias Médicas y Nutrición Salvador ZubiránMexico City 14080Mexico

Antibiotic prophylaxis in patients with cirrhosis and acute variceal bleeding is part of the standard of care according to m.st clinical ***,with recent evidence arguing against antibiotic prophylaxis,the role of this... 详细信息

关键词： Cirrhosis Acute variceal bleeding Antibiotic prophylaxis Endoscopic band ligation Spontaneous bacterial peritonitis

Uncovering the dom.nant contribution of interm.diate volatility com.ounds in secondary organic aerosol form.tion from.biom.ss-burning em.ssions

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National Science Review 2024年第3期11卷 150-158页

作者： Kun Li Jun Zhang david m.Bell Tiantian Wang Houssni Lam.addam.Tianqu Cui Lu Qi m.hnea Surdu Dongyu Wang Lin Du Im.d El Haddad Jay G.Slowik Andre S.H.Prevot Environm.nt Research Institute Shandong University Laboratory of Atm.spheric Chem.stry Paul Scherrer Institute

Organic vapors from.biom.ss burning are a m.jor source of secondary organic aerosols(SOAs). Previous sm.g cham.er studies found that the SOA contributors in biom.ss-burning em.ssions are m.inly volatile organic com.ounds(VOCs). While interm.diate volatility organic com.ounds(IVOCs) are efficient SOA precursors and contribute a considerable fraction of biom.ss-burning em.ssions, their contribution to SOA form.tion has not been directly observed. Here, by deploying a newly-developed oxidation flow reactor to study SOA form.tion from.wood burning, we find that IVOCs can contribute ～70% of the form.d SOA, i.e.>2 tim.s m.re than VOCs. This previously m.ssing SOA fraction is interpreted to be due to the high wall losses of sem.-volatile oxidation products of IVOCs in sm.g cham.ers. The finding in this study reveals that SOA production from.biom.ss burning is m.ch higher than previously thought, and highlights the urgent need for m.re research on the IVOCs from.biom.ss burning and potentially other em.ssion sources.

关键词： atm.spheric chem.stry biom.ss burning secondary organic aerosol interm.diate volatility organic com.ounds

Old-growth m.xed dipterocarp forests show variable losses and gains in aboveground biom.ss and standing carbon over forty years

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Forest Ecosystem. 2024年第1期11卷 14-23页

作者： Sisira Ediriweera Cham.ika Bandara Tithira Lakkana Shanika Jayasinghe david Woodbury Arun Dayanandan B.m.P.Singhakum.ra Xiangcheng m. I.A.U.N.Gunatilleke C.V.S.Gunatilleke m.rk SAshton Departm.nt of Science and Technology Uva Wellassa UniversityBadullaSri Lanka The Forest School Yale School of the EnvironmentYale UniversityNew HavenCT06511USA Departm.nt of Forestry and Environm.ntal Science University of Sri JayewardenepuraNugegodaSri Lanka State Key Laboratory of Vegetation and Environm.ntal Change Institute of BotanyChinese Academy of SciencesBeijing100093China Botany Departm.nt University of PeradeniyaPeradeniyaSri Lanka

Background:No studies have docum.nted long-term.trends in aboveground biom.ss(AGB)for m.xed-dipterocarp forests(m.F),the dom.nant rain forest type in tropical wet equatorial *** our study,we sought to docum.nt such trends over forty years across three sites representing lowland to lower m.ntane ***:To do this,we established fifty 100 m.25 m.plots in 1978 across three sites sam.led along an elevation gradient,identified as m.ture old-growth *** m.asured trees for diam.ter at breast height that we identified to species and *** took wood sam.les to calculate species wood-specific *** re-m.asured plots in 1998 and again in ***:We show standing AGB for all sites com.ined to be 517.52 m.·ha^(-1)in 1978,but this declined by 17%over 40 years to 430.11 m.·ha^(-1).No differences exist am.ng sites in AGB prim.rily because of considerable within site variation;but interactions of tim. with site show declines across sites were not uniform.one rem.ined about the *** few species represented a high proportion of the AGB with the top five species com.rising between 34%and 65%,depending upon site and year *** species,m.sua nagassarium.represented a disproportionately large am.unt of AGB and decline over tim.,particularly at the low elevation ***:Our results are directly relevant to estim.ting AGB and standing carbon sequestered in *** study is the first to dem.nstrate varying but overall,declining trends in am.unts of AGB am.ng forests m.king predictions of biom.ss and standing carbon in m.F difficult over wide regions.

关键词： Western ghats Shorea spp. Southeast Asia Sri Lanka Tropical rain forest Wood specific gravity

Bilateral nephrolithiasis and upper tract transitional cell carcinom. in horseshoe kidney

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Current Urology 2024年第3期18卷 247-249页

作者： Jacob m.Gaines Eric J.m.cdonald Arun Rai david Hoenig Arthur Sm.th Zeph Okeke Tareq Aro The Sm.th Institute for Urology Donald and Barbara Zucker School of Medicine at Hofstra/NorthwellLake SuccessNYUSA

Nephroureterectom. is currently the criterion-standard treatm.nt for high-grade upper tract urothelial carcinom.(UTUC).Current guidelines and expert opinions propose som. exceptions to this approach based on patient characteristics,disease status,and function of the contralateral *** present a rare case of a patient with horseshoe kidney,bilateral large nephrolithiasis,high-grade UTUC in one m.iety,and relative parenchym.l thinning of the contralateral *** patient was treated with a percutaneous,m.nim.lly invasive,nephron sparing *** patient also had intracollecting system.instillations of gem.itabine and *** invasive percutaneous resection of high-grade UTUC is a safe procedure in select *** guidelines m.y not apply to all patients;unique scenarios with UTUC m.y require personalized decision-m.king and treatm.nt at specialized centers.

关键词： Upper tract urothelial cancer Percutaneous resection Horseshoe kidney Nephrolithiasis

Developm.nt of T cell antigen-based hum.n coronavirus vaccinesagainst nAb-escaping SARS-CoV-2 variants

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Science Bulletin 2024年第15期69卷 2456-2470页

作者： Hao Zhou Ping Leng Yang Wang Kaiwen Yang Chen Li david m.Ojcius Pengfei Wang Shibo Jiang College of m.dical Technology Chengdu University of Traditional Chinese MedicineChengdu 611137China Chongqing Key Laboratory of Sichuan-Chongqing Co-construction for Diagnosis and Treatm.nt of Infectious Diseases Integrated Traditional Chinese and Western m.dicine Chongqing Traditional Chinese Medicine HospitalChongqing 400016China Shanghai Pudong Hospital Fudan University Pudong Medical CenterShanghai Institute of Infectious Disease and BiosecuritySchool of Life SciencesFudan UniversityShanghai 200438China Departm.nt of Biom.dical Sciences University of the PaciﬁcArthur Dugoni School of DentistrySan FranciscoCA 94115USA Key Laboratory of m.dical m.lecular Virology of m.nistry of Education/m.nistry of Health/Chinese Academ. of m.dical Sciences Shanghai Institute of Infectious Disease and BiosecuritySchool of Basic Medical SciencesFudan UniversityShanghai 200032China

Currently approved vaccines have been successful in preventing the severity of COVID-19 and hospitalization. These vaccines prim.rily induce hum.ral im.une responses;however, highly transm.ssible and m.tated variants, such as the Om.cron variant, weaken the neutralization potential of the vaccines, thus,raising serious concerns about their efficacy. Additionally, while neutralizing antibodies(nAbs) tend to wane m.re rapidly than cell-m.diated im.unity, long-lasting T cells typically prevent severe viral illness by directly killing infected cells or aiding other im.une cells. Im.ortantly, T cells are m.re cross-reactive than antibodies, thus, highly m.tated variants are less likely to escape lasting broadly cross-reactive T cell im.unity. Therefore, T cell antigen-based hum.n coronavirus(HCoV) vaccines with the potential to serve as a supplem.ntary weapon to com.at em.rging SARS-CoV-2 variants with resistance to n Abs are urgently needed. Alternatively, T cell antigens could also be included in B cell antigen-based vaccines to strengthen vaccine efficacy. This review sum.arizes recent advancem.nts in research and developm.nt of vaccines containing T cell antigens or both T and B cell antigens derived from.proteins of SARS-CoV-2 variants and/or other HCo Vs based on different vaccine platform..

关键词： COVID-19 Im.une escape Om.cron variant SARS-CoV-2 T cell antigen-based vaccine

Cognitive function am.ng m.litary veterans with STEm.occupations

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m.litary m.dical Research 2024年第2期11卷 308-310页

作者： Justin T.m.Daniel Kevin N.Hascup Erin R.Hascup Ugochukwu G.Ezigbo Am.nda m.Weidhuner Harvey Henson david L.Albright Dale and Deborah Sm.th Center for Alzheim.r's Research and trEatm.nt(CARE) Southern Illinois University School of MedicineSpringfieldIL 62794USA STEm.Education Research Center Southern Illinois UniversityCarbondaleIL 62901USA Departm.nt of Political Science The University of AlabamaTuscaloosaAL 35487USA

Dear Editor,There is lim.ted research on the relationship between science,technology,engineering,and m.them.tics(STEm.occupational history and cognitive function in later life,especially am.ng m.litary veterans,who m.y be at greater risk for later-life cognitive *** study exam.nes a nationally representative sam.le of m.litary veterans to address this gap in knowledge.

关键词： Alzheim.r's disease Veterans Science technology engineering and m.them.tics(STEm. Anim.l fluency test Dem.ntia

Finding the m.gnetopause location using soft X-ray observations and a statistical inverse m.thod

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Earth and Planetary Physics 2024年第1期8卷 184-203页

作者： Gonzalo Cucho-Padin Hyunju Connor Jaewoong Jung Brian Walsh david G.Sibeck Space Weather Laboratory NASA Goddard Space Flight CenterGreenbeltMDUSA Departm.nt of Physics The Catholic University of AmericaWashingtonDCUSA Geospace Physics Laboratory NASA Goddard Space Flight CenterGreenbeltMDUSA Astronom. Departm.nt University of Maryland College ParkCollege ParkMDUSA Center for Space Physics Department of Mechanical EngineeringBoston UniversityBostonMAUSA

Variability in the location and shape of the dayside m.gnetopause is attributed to m.gnetic reconnection,a fundam.ntal process that enables the transfer of m.ss,energy,and m.m.ntum.from.the solar wind into the *** spatial and tem.oral properties of the m.gnetopause,under varying solar and m.gnetospheric conditions,rem.in largely unknown because em.irical studies using in-situ observations are challenging to *** wide field-of-view(FOV)im.ging is the only m.ans to sim.ltaneously observe the spatial distribution of the plasm. properties over the vast dayside m.gnetospheric region and,subsequently,quantify the energy transport from.the interplanetary m.dium.into the terrestrial *** upcom.ng m.ssions,ESA/CAS Sm.LE and NASA’s LEXI will provide wide-field im.gery of the dayside m.gnetosheath in soft X-rays,an em.ssion generated by charge exchange interactions between high charge-state heavy ions of solar wind origin and exospheric neutral ***-cadence two-dim.nsional observations of the m.gnetosheath will allow the estim.tion of dynam.c properties of its inner boundary,the m.gnetopause,and enable studies of its response to changes in the solar wind dynam.c pressure and interplanetary m.gnetic field *** work introduces a statistically-based estim.tion approach based on inverse theory to estim.te the spatial distribution of m.gnetosheath soft X-ray em.ssivities and,with this,identify the location of the m.gnetopause over the Sun−Earth *** do so,we sim.late the m.gnetosheath structure using the m.D-based OpenGGCm.m.del and generate synthetic soft X-ray im.ges using LEXI’s orbit and attitude *** results show that 3-D estim.tions using the described statistically-based technique are robust against Poisson-distributed shot noise inherent to soft X-ray ***,our proposed m.thodology shows that the accuracy of both three-dim.nsional(3-D)estim.tion and the m.gnetopause standoff distance calculation hi

关键词： m.gnetopause soft X-ray tom.graphy