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Early Phases of.Star f.rmation: Testing chemical Tools

Research in Astronomy and Astrophysics 2024年第1期24卷 96-118页

作者： N.c.martinez S.Paron coNIcET-Universidad de Buenos Aires.Instituto de Astronomía y f.sica del Espacio Ciudad Universitaria(C1428EGA)Ciudad Autónoma de Buenos AiresArgentina

Star-f.rming processes strongly inf.uence the ISm ***,many high-quality databases are available at millimeter *** them,it is possible to carry out studies that review and deepen previous *** these studies involve large samples of.sources,it is pref.rred to use direct tools to study the molecular *** the aim of.testing these tools such as the use of.the HcN/HNc ratio as a thermometer,and the use of.H^(13)co^(+),Hc_(3)N,N_(2)H^(+) and c_(2)H as "chemical clocks," we present a molecular line study toward 55 sources representing massive young stellar objects at dif.erent evolutionary stages:inf.ared dark clouds(IRDcs),highmass protostellar objects(HmPos),hot molecular cores(Hmcs) and ultracompact H II *** f.und that the use of.the HcN/HNc ratio as a universal thermometer in the ISm should be taken with care because the HcN optical depth is a big issue that can af.ect the ***,this tool should be utilized only af.er a caref.l analysis of.the HcN spectrum,checking that no line,neither the main nor the hyperf.ne ones,presents absorption *** point out that the analysis of.the emission of.H^(13)co^(+),Hc_(3)N,N_(2)H^(+) and c_(2)H could be usef.l to trace and distinguish regions among IRDcs,HmPos and *** molecular line widths of.these f.ur species increase f.om the IRDc to the Hmc stage,which can be a consequence of.the gas dynamics related to the starf.rming processes taking place in the molecular *** results not only contribute with more statistics,acting as a probe of.such chemical tools,usef.l to obtain inf.rmation in large samples of.sources,but also complement previous works through the analysis of.other types of.sources.

关键词： stars:f.rmation ISm:molecules ISm:clouds

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metal-modulated epitaxy of.mg-doped Al_(0.80)In_(0.20)N-based layer f.r application as the electron blocking layer in deep ultraviolet light-emitting diodes

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Journal of.Semiconductors 2024年第5期45卷 80-89页

作者： Horacio Irán Solís-cisneros carlos Alberto Hernández-Gutiérrez Enrique campos-González máximo López-López optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico Departamento de f.sica Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico Departamento de f.sica Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of.p-AlInN layers doped with mg by plasma-assisted molecular beam epitaxy(PAmBE).AlInN was grown with an Al molar f.action of.0.80 by metal-modulated epitaxy(mmE)with a thickness of.180 nm on Si(111)substrates using AlN as buf.er *** substrate temperatures were used to enhance the incorporation of.indium atoms into the alloy without clustering,as conf.rmed by X-ray dif.raction(XRD).cathodoluminescence measurements revealed ultraviolet(UV)range ***,Hall ef.ect measurements indicated a maximum hole mobility of.146 cm^(2)/(V∙s),corresponding to a f.ee hole concentration of.1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPS)estimating the alloy composition and extracting the f.rmi level by valence band ***-doped AlInN layers were studied f.r use as the electron-blocking layer(EBL)in LED *** varied the Al composition in the EBL f.om 0.84 to 0.96 molar f.action to assess its theoretical ef.ects on electroluminescence,carrier concentration,and electric f.eld,using SILVAco *** results f.om this study highlight the importance and capability of.producing high-quality mg-doped p-AlInN layers through *** simulations suggest that an Al content of.0.86 is optimal f.r achieving desired outcomes in electroluminescence,carrier concentration,and electric f.eld.

关键词： metal-modulated epitaxy AlInN DUV-LED EBL simulation

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oligodendroctyes:the f.rgotten players of.diabetes pathophysiology

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Neural Regeneration Research 2024年第11期19卷 2349-2350页

作者： Juan Antonio López-Villodres Beatriz García-Díaz Departamento f.siología Humana Histología HumanaAnatomía Patológica y Educación Física y DeportivaFacultad de MedicinaUniversidad de MálagaMálagaSpain UGc Neurociencia.Instituto de Investigación Biomédica de málaga y Plataf.rma en Nanomedicina(IBImA Plataf.rma Bionand) MálagaSpain

oligodendrocytes(oLs),glial cells that provide myelin sheaths to axons in the central nervous system(cNS),have a dual ***,this myelin f.tty cover around the axons protects the nerves and is crucial f.r the saltatory propagation of.action *** and not less important,oLs provide trophic support to neurons and ***,oL metabolism is important f.r oL well-being and the proper accomplishment of.their f.nctions,and oL metabolism energetics directly af.ect the energy metabolism of.neighboring neurons.

关键词： metabolism nerves myelin

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A simulation study f.r a cost-ef.ective PET-like detector system intended to track particles in granular assemblies

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Particuology 2024年第1期84卷 117-125页

作者： Josephine oppotsch Antonios Athanassiadis miriam f.itsch f.itz-Herbert Heinsius Thomas Held Nikoline Hilse Viktor Scherer matthias Steinke Ulrich Wiedner Ruhr-Universität Bochum Institut für Experimentalphysik I44801 BochumGermany Ruhr-Universität Bochum Lehrstuhl für Energieanlagen und Energieprozesstechnik44801 BochumGermany

Since many industrial applications rely on the processing of.densely packed and moving granular ma-terial,obtaining bulk internal inf.rmation on the particle movement inside the reactors is of.great *** inf.rmation can be delivered by Positron Emission Particle Tracking(PEPT).By marking pellets with a positron-emitting radioisotope,the position of.these tracer particles can be determined via the time-of.f.ight dif.erences of.the emitted gamma-ray *** current paper proposes a PET-like detector system based on cost-ef.ective organic plastic scintillators instead of.the more common but expensive inorganic *** system is currently under construction and was tested f.r its resolution and ef.iciency in this simulation *** monte carlo simulations and the sof.ware toolkit Geant4,three dif.erent geometries(an empty glass box,a generic grate system,and a cubic box of.1 m3 completely f.lled with pellets)were investigated,leading to a spatial resolution in the millimeter range and an ef.iciency,def.ned as the ratio of.reconstructed decay locations to simulated decays,of.2.7%,1.4%,and 0.3%.

关键词： Positron emission particle tracking Geant4 monte carlo method Time-of.f.ight Plastic scintillators Silicon photomultipliers(SiPms)

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Ef.icient removal of.the recalcitrant metamizole contaminant f.om drinking water by using a caLacoo_(9) perovskite supported on recycled polyethylene

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Journal of.Environmental Sciences 2024年第2期136卷 56-67页

作者： Ernesto Valadez-Renteria christian Perez-carrasco Dulce yolotzin medina-Velazquez Vicente Rodriguez-Gonzalez Jorge oliva coNAcyT-División de materiales Avanzados Instituto Potosino de Investigación Científica y Tecnológica A.C.San Luis PotosíSLP 78216México División de ciencias Básicas e Ingeniería Universidad Autónoma Metropolitana AzcapotzalcoCol.Reynosa-TamaulipasC.P.MéxicoDF 02200México

metamizole(mZ)is a widely used anti-inf.ammatory *** to its common use,this contaminant is f.und in sewage and *** order to reduce the contamination produced by the mZ,we f.bricated in this work a photocatalytic composite using recycled polyethylene(RPE)and the caLacoo_(9)(Lcco)*** nanoparticles had a microplate-like morphology and sizes of.1.4–5.5μm according to the analysis of.*** photocatalytic properties of.the Lcco powders were evaluated under ultraviolet-visible(UV-Vis)irradiation and f.und a removal ef.iciency of.96%.When the RPE+Lcco composite was employed f.r the photocatalytic degradation of.mZ,a maximum degradation of.92.5%was *** inf.uence of.the pH on the photocatalytic activity was also studied and f.und that an initial pH=3 produced a total degradation of.mZ af.er 240 min of.UV-Vis ***,three reuse cycles were carried out f.r the pure Lcco powders and f.r the RPE+Lcco composites and f.und that the maximum loss of.degradation was 5%.f.rthermore,scavenger experiments demonstrated that the super oxide and hydroxyl radicals are f.rmed during the photocatalytic reaction and were responsible f.r the degradation of.***,the X-ray photoelectron-spectroscopy and Raman analysis demonstrated the f.rmation of.def.cts(oxygen vacancies),those ones delayed the electron-hole recombination,which in turn,enhanced the degradation of.the ***,the studies perf.rmed in this work proved that composites made with recycled plastics and Lcco perovskites are a low-cost and f.asible alternative f.r the cleaning of.water sources polluted with pharmaceutical compounds.

关键词： Photocatalysis metamizole Pharmaceutical contaminant UV-Vis irradiation Perovskite

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Endoplasmic reticulum stress improved chicken tenderness,promoted apoptosis and autophagy during postmortem ageing

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f.od Science and Human Wellness 2024年第4期13卷 2141-2151页

作者： yuwei chai Lin chen Shuya Xiang Linxuan Wu Xuebo Liu Jun Luo Xianchao f.ng college of.f.od Science and Engineering Northwest A&F UniversityYangling 712100China college of.Animal Science and Technology Northwest A&F UniversityYangling 712100China

In this study,endoplasmic reticulum(ER)stress inducer tunicamycin(Tm)and inhibitor 4-phenylbutyric acid(4-PBA)were used to treat postmortem chicken breast muscle to investigate changes in tenderness and ef.ects on apoptosis and autophagy during 5 days ***-induced ER stress reduced shear f.rce,enhanced myof.bril f.agmentation index(mf.),disrupted myof.bril structure,increased desmin degradation,and activatedμ-calpain and *** addition,Tm-induced ER stress increased the expression of.Bax,Bim,and cytochrome c,and decreased the expression of.Bcl-x ***,Tm-induced ER stress improved the conversion of.Lc3I to Lc3II,raised the expression of.Beclin-1,and decreased the expression of.p62,PI3K,and m *** opposite results were observed af.er 4-PBA *** results suggested that ER stress could improve chicken tenderness,promote apoptosis and autophagy during chicken postmortem ageing.

关键词： Endoplasmic reticulum stress Tenderness Apoptosis Autophagy chicken

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Synchronized of.-harmonic probe laser with highly variable pulse duration f.r laser-plasma interaction experiments

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High Power Laser Science and Engineering 2024年第1期12卷 99-107页

作者： J.Hornung y.Zobus H.Lorenté c.Brabetz B.Zielbauer V.Bagnoud GSI Helmholtzzentrum f.r Schwerionenf.rschung GmbH DarmstadtGermany Institut d’optique UniversitéParis-SaclayPalaiseauFrance Institut f.r Angewandte Physik Technische Universität DarmstadtDarmstadtGermany

This paper presents the development and experimental utilization of.a synchronized of.-harmonic laser system designed as a probe f.r ultra-intense laser±plasma interaction experiments. The system exhibits a novel seed-generation design,allowing f.r a variable pulse duration spanning over more than three orders of.magnitude, f.om 3.45 picoseconds to 10 nanoseconds. This makes it suitable f.r various plasma diagnostics and visualization techniques. In a side-view conf.guration, the laser was employed f.r interf.rometry and streaked shadowgraphy of.a laser-induced plasma while successf.lly suppressing the self.emission background of.the laser±plasma interaction, resulting in a signal-to-self.emission ratio of.110 f.r this setup. These properties enable the probe to yield valuable insights into the plasma dynamics and interactions at the PHELIX f.cility and to be deployed at various laser f.cilities due to its easy-to-implement design.

关键词： interf.rometry laser-plasma interaction of.-harmonic probe laser streaked shadowgraphy

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Intensive management enhances mycorrhizal respiration but decreases f.ee-living microbial respiration by af.ecting microbial abundance and community structure in moso bamboo f.rest soils

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Pedosphere 2024年第2期34卷 508-519页

作者： Wenhao JIN Jiangf.i GE Shuai SHAo Liyuan PENG Jiajia XING chenf.i LIANG Junhui cHEN Qiuf.ng XU Hua QIN State Key Laboratory of.Subtropical Silviculture Zhejiang A&F UniversityHangzhou 311300China School of.Environmental and Resource Sciences Zhejiang A&F UniversityHangzhou 311300China

Intensive management is known to markedly alter soil carbon(c)storage and turnover in moso bamboo f.rests compared with extensive ***,the ef.ects of.intensive management on soil respiration(RS)components remain *** study aimed to evaluate the changes in dif.erent RScomponents(root,mycorrhizal,and f.ee-living microorganism respiration)in moso bamboo f.rests under extensive and intensive management practices.A1-year in-situ microcosm experiment was conducted to quantif. the RScomponents in moso bamboo f.rests under the two management practices using mesh screens of.varying *** results showed that the total RSand its components exhibited similar seasonal variability between the two management *** with extensive management,intensive management signif.cantly increased cumulative respiration f.om mycorrhizal f.ngi by 36.73%,while decreased cumulative respiration f.om f.ee-living soil microorganisms by 8.97%.moreover,the abundance of.arbuscular mycorrhizal f.ngi(Amf.increased by 43.38%,but bacterial and f.ngal abundances decreased by 21.65%and 33.30%,respectively,under intensive *** management practices signif.cantly changed the bacterial community composition,which could be mainly explained by soil pH and available *** f.ngi and intensive management af.ected the interrelationships between bacterial *** equation modeling indicated that intensive management changed the cumulative RSby elevating Amf.abundance and lowering bacterial *** concluded that intensive management reduced the microbial respiration-derived c loss,but increased mycorrhizal respiration-derived c loss.

关键词： arbuscular mycorrhizal f.ngi extensive management microbial co-occurrence network root respiration soil organic c soil respiration structural equation model

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Laboratory and numerical modelling of.irrigation inf.ltration and nitrogen leaching in homogeneous soils

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Pedosphere 2024年第1期34卷 146-158页

作者： Lei WU Ruizhi LI yan WANG Zongjun GUo Jiaheng LI Hang yANG Xiaoyi mA Key Laboratory of.Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling 712100China Blackland Research and Extension center Texas A&M AgriLife ResearchTexas A&M UniversityTemple TX 76502USA State Key Laboratory of.Soil Erosion and Dryland f.rming on the Loess Plateau Northwest A&F UniversityYangling 712100China college of.Water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China

Nitrogen (N) plays a key role in crop growth and production;however,data are lacking especially regarding the interaction of.biochar,grass cover,and irrigation on N leaching in saturated soil *** soil columns with 20-cm diameter and 60-cm height were designed to characterize the ef.ects of.dif.erent grass cover and biochar combinations,i.e.,bare soil+0%biochar (control,cK),perennial ryegrass+0%biochar (c1),f.stuca arundinacea+0%biochar (c2),perennial ryegrass+1%biochar (c3),perennial ryegrass+2%biochar (c4),perennial ryegrass+3%biochar (c5),***+1%biochar (c6),***+2% biochar (c7),and ***+3%biochar (c8),on periodic irrigation inf.ltration and N leaching in homogeneous loess soils f.om July to December *** in cK were 10.2%–35.3%higher than those in c1 and *** perennial ryegrass and *** decreased the volumes of.leachates and delayed the leaching process in the 1%,2%,and 3%biochar treatments,and the vertical leaching rate decreased with biochar *** N leaching losses were concentrated in the f.rst f.w leaching tests,and both total N (TN) and nitrate (No_(3)^(-))-N concentrations in cK and c1–c8 decreased with increasing leaching test *** addition (1%,2%,and 3%) could f.rther reduce the leaching risk of.No_(3)^(-)-N and the No_(3)^(-)-N loss decreased with biochar ***,compared to 1%biochar,2% biochar promoted the leaching of.TN under both grass cover *** N leaching losses in cK,c1,c2,c3,c4,c6,and c7 were primarily in the f.rm of.No_(3)^(-)-*** these treatments,cK,c1,and c2had the highest cumulative leaching f.actions No_(3)^(-)-N (>90%),f.llowed by those in c3,c4,c6,and c7 (>80%).The cumulative leaching f.action of.No_(3)^(-)-N decreased with increasing leaching test times and biochar addition,and 3%biochar addition (i.e.,c5 and c8) reduced it to approximately 50%.The one-dimensional advective-dispersive-reactive transport equation can be used as an ef.ective nume

关键词： leaching loss nitrate nitrogen biochar grass cover analytical modelling

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Inf.uence of.manuf.cturing process-induced geometrical def.cts on the energy absorption capacity of.polymer lattice structures

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Def.nce Technology（防务技术） 2024年第5期35卷 47-59页

作者： Alexandre Riot Enrico Panettieri Antonio cosculluela marco montemurro Universite de Bordeaux Arts et Metiers Institute of TechnologyCNRSINRABordeaux INPHESAM UniversiteI2M UMR 5295F-33405 TalenceFrance f.ench Atomic Energy commission Route des GargailsCedexF-33114Le BarpFrance

modern additive manuf.cturing processes enable f.bricating architected cellular materials of.complex shape,which can be used f.r dif.erent *** them,lattice structures are increasingly used in applications requiring a compromise among lightness and suited mechanical properties,like improved energy absorption capacity and specif.c stif.ness-to-weight and strength-to-weight ratios.A dedicated modeling strategy to assess the energy absorption capacity of.lattice structures under uni-axial compression loading is presented in this *** numerical model is developed in a non-linear f.amework accounting f.r the strain rate ef.ect on the mechanical responses of.the lattice *** geometries,i.e.,cubic body centered cell,octet cell,rhombic-dodecahedron and truncated cuboctahedron 2+,are ***,the inf.uence of.the relative density of.the representative volume element of.each geometry,the strain-rate dependency of.the bulk material and of.the presence of.the manuf.cturing process-induced geometrical imperf.ctions on the energy absorption capacity of.the lattice structure is *** main outcome of.this study points out the importance of.correctly integrating geometrical imperf.ctions into the modeling strategy when shock absorption applications are aimed f.r.

关键词： Lattice structures Architected cellular materials Dynamic simulation Energy absorption Geometrical imperf.ction Additive manuf.cturing

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