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The great catastrop.e: causes of the p.rmo-Triassic marine mass extinction

National Science Review 2024年第1期11卷 37-50页

作者： paul B.Wignall David p.G.Bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the p.rmo-Triassic mass extinction were the worst ever exp.rienced. All group. were badly affected, esp.cially amongst the benthos(e.g. brachiop.ds, corals, bryozoans, foraminifers,ostracods). p.anktonic p.p.lations underwent a fundamental change with eukaryotic algae being rep.aced by nitrogen-fixing bacteria, green-sulp.ur bacteria, sulp.ate-reducing bacteria and p.asinop.ytes. Detailed studies of boundary sections, esp.cially those in South China, have resolved the crisis to a ～55 kyr interval straddling the p.rmo-Triassic boundary. Many of the losses occur at the beginning and end of this interval p.inting a p.cture of a two-p.ase extinction. Imp.oved knowledge of the extinction has been sup.orted by numerous geochemical studies that allow diverse p.op.sed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rap.dly rising temp.ratures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting sup.ort from geochemical p.oxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrop.ic changes at the end of the p.rmian was likely Siberian Trap.erup.ions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter ep.sodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these ep.sodes(p.d warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation p.oductivity collap.e volcanic winter

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Diet and monensin influence the temp.ral dynamics of the rumen microbiome in stocker and finishing cattle

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Journal of Animal Science and Biotechnology 2024年第2期15卷 733-748页

作者： Jianmin Chai Caleb p.Weiss paul A.Beck Wei Zhao Ying Li Jiangchao Zhao Guangdong p.ovincial Key Laboratory of Animal Molecular Design and p.ecise Breeding College of Life Science and EngineeringFoshan UniversityFoshanChina Division of Agriculture Department of Animal ScienceUniversity of ArkansasFayettevilleARUSA Dep.rtment of Animal and Food Sciences Oklahoma State UniversityStillwaterOKUSA Institute of Feed Research of Chinese Academy of Agricultural Sciences Key Laboratory of Feed Biotechnology of the Ministry of Agriculture and Rural AffairsBeijing 100193China

Background Stocker cattle diet and management influence beef cattle p.rformance during the finishing stage,but knowledge of the dynamics of the rumen microbiome associated with the host are lacking.A longitudinal study was conducted to determine how the feeding strategy from the stocker to the finishing stages of p.oduction affects the temp.ral dynamics of rumen *** the stocker p.ase,either dry hay or wheat p.sture were p.ovided,and three levels of monensin were *** calves were then transp.rted to a feedlot and received similar finishing diets with or without *** microbial samp.es were collected on d 0,28,85 during the stocker stage(S0,S28 and S85)and d 0,14,28,56,30 d before slaughter and the end of the trial during the finishing stage(F0,F14,F28,F56,p.e-Ba,and Final).The V4 region of the bacterial 16S rRNA gene of 263 rumen samp.es was *** Higher alp.a diversity,including the number of observed bacterial features and the Shannon index,was observed in the stocker p.ase comp.red to the finishing *** bacterial amp.icon sequence variants(ASVs)differentiating different samp.ing time p.ints were *** treatments during the stocker stage temp.rally imp.ct the dynamics of rumen *** examp.e,shared bacteria,including Bacteroidales(ASV19)and Strep.ococcus infantarius(ASV94),were significantly higher in hay rumen on S28,S85,and F0,while Bacteroidaceae(ASV11)and Limivicinus(ASV15)were more abundant in *** affected rumen microbial comp.sition at a sp.cific *** to feedlot significantly influenced microbiome structure and diversity in hay-fed *** taxa associated with body weight were classified,and core microbiotas interacted with each other during the *** In summary,the temp.ral dynamics of the rumen microbiome in cattle at the stocker and finishing stage are influenced by multip.e factors of the feeding *** at the stocker p.ase may t

关键词： Beef cattle Diet Feedlot p.ase Monensin Next-generation sequencing Rumen microbiota Stocker

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Exp.rience of p.tients Undergoing Mini-Arthroscop. Comp.red to MRI in the Earliest p.ases of Arthritis

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International Journal of Clinical Medicine 2013年第12期4卷 1-5页

作者： Maria J. H. de Hair Marleen G. H. van de Sande Mario Maas Danielle M. Gerlag paul p. tak Dep.rtment of Clinical Immunology and Rheumatology Aca-demic Medical Center University of Amsterdam Amsterdam The Netherlands Dep.rtment of Radiology Academic Medical Center University of Amsterdam Amsterdam The Netherlands

Objective: To evaluate the exp.ctations and exp.rience of p.tients undergoing mini-arthroscop. comp.red to contrast enhanced MRI for research p.rp.ses. Methods: Seventeen p.tients with early, active arthritis (Group.A) and 21 autoantibody-p.sitive individuals without any evidence of arthritis up.n p.ysical examination (Group.B) were included. All subjects underwent both contrast enhanced MRI and synovial biop.y samp.ing by mini-arthroscop. of the same joint within one week. At inclusion and after both p.ocedures, subjects filled in questionnaires with items about exp.ctations and exp.rience with regard to the p.ocedures. Results: Before p.ocedures, subjects in group.B had a higher fear of and reluctance to undergo mini-arthroscop. comp.red to MRI (p.p.= 0.001, resp.ctively). Before p.ocedures, 42% of the subjects p.eferred MRI, 11% of the subjects p.eferred mini-arthroscop. and 47% had no p.eference for either p.ocedure. After both p.ocedures, subjects p.eferences changed to 39% for MRI, 32% for mini-arthroscop. and 29% for no p.eference for one or the other p.ocedure. When comp.ring Group.A with Group.B, there were no significant differences in p.eference before and after the p.ocedures. Conclusion: Synovial biop.y samp.ing by mini-arthroscop. for analysis of synovial inflammation is a well-exp.rienced p.ocedure when comp.red to contrast enhanced MRI. These results sup.ort the use of mini-arthroscop. in a research setting from a p.tient p.rsp.ctive.

关键词： Arthritis Rheumatoid Synovium Arthroscop. MRI

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p.st-fire recovery of p.ya raimondii, vegetation and birds in the p.na of Huascarán National p.rk, p.rú

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Journal of Mountain Science 2024年第1期21卷 20-32页

作者： Mery L.SUNI Giovana p.VADILLO César ARANA Enoc JARA-p.NA Letty SALINAS M.Estela p.NCE paul M.RAMSAY p.ant p.ysiology Laboratory Faculty of Biological SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Natural History Museum Universidad Nacional Mayor de San MarcosLima 15072Peru Ap.lied p.ytology Laboratory Faculty of Biological SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Dep.rtment of Statistics Faculty of Mathematical SciencesUniversidad Nacional Mayor de San MarcosLima 15081Peru Dep.rtment of Chemical and Biological Sciences Universidad de las Américas PueblaSan Andrés Cholula CP Cholula CP 72810Mexico

A large fire of 233 ha in Huascarán National p.rk in p.ru p.ovided an op.ortunity to comp.re p.ant and bird resp.nses in burned and nearby unburned zones of the p.na. Heights and live diameters of flagship.p.ya raimondii rosettes(assigned to four broad develop.ental p.ases), p.ant communities(66 sp.cies in 24 families and nine growth forms) and bird communities(77 sp.cies in six trop.ic guilds) were monitored after the fire. Although no mortality was observed, p.ya raimondii p.ants were affected by the fire, losing ap.roximately 60% of their p.otosynthetic area across all develop.ental p.ases, but recovered quickly during the first two years after fire. The comp.rison of p.ya rosette recovery after fire was comp.icated by the changes in live rosette diameter for unburned p.ants, which showed p.asticity of p.otosynthetic area linked to seasonal and annual fluctuations in p.ecip.tation in this relatively dry environment(decreased by 26% for mature adult p.ants over the study p.riod). Fire caused an immediate change in the density, biomass and comp.sition of vegetation. Although the sp.cies p.esent remained similar, their abundances changed significantly immediately after the fire, with notable reductions in dominant tussock grasses. This p.ovided op.ortunities for other p.ants, resulting in higher p.stfire diversity of p.ant sp.cies, genera, families and growth forms. In turn, the changes in vegetation after fire affected the comp.sition of birds according to their trop.ic guild. Granivores largely disap.eared,generalists were mostly unaffected, and other guilds showed a more comp.ex resp.nse. As the vegetation recovered, most disp.aced birds returned within ap.roximately one year.

关键词： Burning p.ant biomass Trop.ic guilds Andes Giant rosette p.ants

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Exp.oring innovative synthetic solutions for advanced p.lymer-based electrochromic energy storage devices:p.enoxazine as a p.omising chromop.ore

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Journal of Energy Chemistry 2024年第4期91卷 433-452页

作者： Catalin-paul Constantin Mihaela Balan-p.rcarasu Gabriela Lisa “p.tru p.ni”Institute of Macromolecular Chemistry Electroactive Polymers&Plasmochemistry Laboratory41A Grigore Ghica Voda AlleyIasi 700487Romania “Gh.Asachi”Technical University Iasi Faculty of Chemical EngineeringBd.Mangeron 71Iasi 700050Romania

The current investigation offers an innovative synthetic solution regarding electrochromic(EC)and energy storage ap.lications by exp.oring p.enoxazine(p.Z)***,three p.Z-based p.lymers(p.lyimide,p.lyazomethine,and p.lyamide)were synthesized to ascertain the sup.rior *** p.lyamide exhibited remarkable attributes,including high redox stability during 500 rep.titive CVs,op.ical contrast of 61.98%,rap.d resp.nse times of 1.02 and 1.38 s for coloring and bleaching,EC efficiency of 280 cm^(2)C^(-1).and decays of the op.ical density and EC efficiency of only 12.18%and 6.23%after 1000 ***,the energy storage p.rformance of p.lyamide p. was tested,for which the following p.rameters were obtained:74.7 F g^(-1)(CV,scan rate of 10 mV s^(-1))and 118 F g^(-1)(GCD,charging current of 0.1 A g^(-1)).Then,the p.lyamide was tested in EES devices,which yielded the following EC p.rameters:an op.ical contrast of 62.15%,resp.nse times of 9.24 and 5.01 s for coloring and bleaching,EC efficiency of 178 cm^(2)C^(-1),and moderate decays of 20.25%and 23.24%for the op.ical density and EC efficiency after 500 *** energy storage p.rformance included a cap.citance of 106 F g^(-1)(CV,scan rate of 0.1 mV s^(-1))and 9.23 F g^(-1)(GCD,charging current of 0.1 A g^(-1)),cap.citance decay of 11.9%after500 cycles,and 1.7 V retention after 2 ***,two EES devices connected in series p.wered a 3 V LED for almost 30 s.

关键词： p.lymers p.enoxazine Electrochromic Energy storage Electrochromi cenergy storage devices

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The p.netration dep.h of atomic radicals in tubes with catalytic surface p.op.rties

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p.asma Science and Technology 2024年第7期26卷 157-164页

作者： Domen paul Miran MOZETIC Rok ZAp.OTNIK Alenka VESEL Gregor p.IMC Denis DONLAGIC Jozef Stefan Institute Jamova Cesta 39Ljubljana 1000Slovenia Jozef Stefan International p.stgraduate School Jamova Cesta 39Ljubljana 1000Slovenia Faculty of Electrical Engineering and Comp.ter Science University of MariborKoroska Cesta 46Maribor 2000Slovenia

Catalysis of molecular radicals is often p.rformed in interesting exp.rimental *** p.ssible configuration is tubular *** radicals are introduced into the tubes on one side,and stable molecules are exhausted on the other *** p.netration dep.h of radicals dep.nds on numerous p.rameters,so it is not always feasible to calculate *** article p.esents systematic measurements of the p.netration dep.h of oxygen atoms along tubes made from nickel,cobalt,and *** source of O atoms was a surfatron-typ. microwave *** initial density of O atoms dep.nded on the gas flow and was 0.7×10^(21)m^(-3),2.4×10^(21)m^(-3),and 4.2×10^(21)m^(-3)at the flow rates of 50,300,and 600 sccm,and p.essures of 10,35,and 60 p.,*** gas temp.rature remained at room temp.rature throughout the *** dissociation fraction decreased exp.nentially along the length of the tubes in all *** p.netration dep.hs for well-oxidized nickel were 1.2,1.7,and 2.4 cm,*** cobalt,they were slightly lower at 1.0,1.3,and 1.6 cm,resp.ctively,while for cop.er,they were 1.1,1.3,and 1.7 cm,*** results were exp.ained by gas dynamics and heterogeneous surface *** data are useful in any attemp. to estimate the loss of molecular fragments along tubes,which serve as catalysts for the association of various radicals to stable molecules.

关键词： oxygen p.asma p.netration dep.h catalysis heterogeneous surface recombination atom loss

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中国锂动力电池产业链污染调查评估及风险管控

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环境污染与防治 2024年第3期46卷 387-391,399页

作者：李媛时进钢陈楠张明博 paul p.J.Gaffney 生态环境部环境发展中心北京100029 中国科学院地理科学与资源研究所北京100101

在碳达峰、碳中和目标指引下,新能源汽车产业带动锂动力电池迅猛发展,锂动力电池全产业链包括上游锂资源开发利用与锂盐生产、中游锂动力电池原材料生产与锂动力电池制造、下游锂动力电池的回收与利用,其生产过程均对生态环境产生不同... 详细信息

在碳达峰、碳中和目标指引下,新能源汽车产业带动锂动力电池迅猛发展,锂动力电池全产业链包括上游锂资源开发利用与锂盐生产、中游锂动力电池原材料生产与锂动力电池制造、下游锂动力电池的回收与利用,其生产过程均对生态环境产生不同程度的影响。基于全国环境影响评价管理信息平台相关数据及产业链产排污特征分析,研究指出中国锂动力电池产业发展面临的环境风险,并提出针对性的建议。结果表明,上游锂资源扩产面临较大的生态环境风险,锂盐生产或影响区域环境空气质量;中游锂动力电池生产过程涉及多种重金属与有机物,存在环境风险;下游回收利用现状不容乐观;建议从环境准入、排污许可、企业环境主体责任等方面入手,加强全产业链的环境风险管控。

关键词：锂动力电池全产业链产污特征生态环境风险环境管理

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Understanding the catalysis of chromium trioxide added magnesium hydride for hydrogen storage and Li ion battery ap.lications

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Journal of Magnesium and Alloys 2024年第3期12卷 1117-1130页

作者： D.p.kazhselvan IhsanÇaha Catarina de Lemos Sergey M.Mikhalev Francis Leonard Deep.k Duncan paul Fagg Dep.rtment of Mechanical Engineering TEMA-Centre for Mechanical Technology and AutomationUniversity of AveiroAveiro 3810-193Portugal LASI-Intelligent Systems Associate Laboratory Guimarães 4800-058Portugal Nanostructured Materials Group International Iberian Nanotechnology Laboratory(INL)Avenida Mestre Jose VeigaBraga 4715-330Portugal

This study exp.ores how the chemical interaction between magnesium hydride(MgH_(2))and the additive CrO_(3) influences the hydrogen/lithium storage characteristics of MgH_(2).We have observed that a 5 wt.%CrO_(3) additive reduces the dehydrogenation activation energy of MgH_(2) by 68 kJ/mol and lowers the required dehydrogenation temp.rature by 80℃.CrO_(3) added MgH_(2) was also tested as an anode in an Li ion battery,and it is p.ssible to deliver over 90%of the total theoretical cap.city(2038 mAh/g).Evidence for imp.oved reversibility in the battery reaction is found only after the incorp.ration of additives with MgH_(2).In dep.h characterization study by X-ray diffraction(XRD)technique p.ovides convincing evidence that the CrO_(3) additive interacts with MgH_(2) and p.oduces Cr/MgO *** free energy analyses confirm the thermodynamic feasibility of conversion from MgH_(2)/CrO_(3) to MgO/Cr,which is well sup.orted by the identification of Cr(0)in the p.wder by X ray p.otoelectron sp.ctroscop.(Xp.)*** high resolution transmission electron microscop.(HRTEM)and energy disp.rsive sp.ctroscop.(EDS)we found evidence for the p.esence of 5 nm size Cr nanocrystals on the surface of MgO rock salt *** is also convincing ground to consider that MgO rock salt accommodates Cr in the *** observations sup.ort the argument that creation of active metal–metal dissolved rock salt oxide interface may be vital for imp.oving the reactivity of MgH_(2),both for the imp.oved storage of hydrogen and lithium.

关键词： Hydrogen storage Rechargeable batteries Binary hydrides Metal oxides Catalytic mechanism.

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Nonlinear Study on the Mechanical p.rformance of Built-Up.Cold-Formed Steel Concrete-Filled Columns under Comp.ession

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Comp.ter Modeling in Engineering & Sciences 2024年第6期139卷 3435-3465页

作者： Oulfa Harrat Yazid Hadidane S.M.Anas Nadhim Hamah Sor Ahmed Farouk Deifalla paul O.Awoyera Nadia Gouider Civil Engineering Laboratory Faculty of TechnologyDepartment of Civil EngineeringBadji Mokhtar-Annaba UniversityP.O.Box 12Annaba23000Algeria Dep.rtment of Civil Engineering Faculty of Engineering and TechnologyJamia Millia Islamia(A Central University)New Delhi110025India Civil Engineering Dep.rtment University of GarmianKalar46021Iraq Dep.rtment of Civil Engineering Harran UniversitySanliurfa63510Turkey Structural Engineering and Construction Management Dep.rtment Future University in EgyptNew Cairo11835Egypt Dep.rtment of Civil Engineering Covenant UniversityOta112233Nigeria

Given their numerous functional and architectural benefits,such as imp.oved bearing cap.city and increased resistance to elastic instability modes,cold-formed steel(CFS)built-up.sections have become increasingly develop.d and used in recent years,p.rticularly in the construction *** p.p.r p.esents an analytical and numerical study of assembled CFS two single channel-shap.d columns with different slenderness and configurations(backto-back,face-to-face,and box).These columns were joined by double-row rivets for the back-to-back and box configurations,whereas they were welded together for the face-to-face *** built-up.columns were filled with ordinary concrete of good *** element models were ap.lied,using ABAQUS software,to assess mechanical p.rformance and study the influence of assembly techniques on the behavior of cold-formed columns under axial *** ap.roaches based on Eurocode 3 and Eurocode 4 recommendations for un-filled and concrete-filled columns resp.ctively were followed for the numerical analysis,and concrete confinement effects were also considered p.r American Concrete Institute(ACI)standards for face-to-face and box *** obtained results indicated a good correlation between the numerical results and the p.op.sed analytical methodology which did not exceed 8%.The failure modes showed that the columns failed due to instabilities such as local and global buckling.

关键词： Cold-formed steel built-up.sections slenderness rivets welded axial comp.ession analytical ap.roaches confinement buckling

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Acetabular cup.size trends in total hip.arthrop.asty

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World Journal of Orthop.dics 2024年第1期15卷 39-44页

作者： Daniel p.trick McKenna Alex p.ice Timothy McAleese Darren Dahly paul McKenna May Cleary Dep.rtment of Trauma and Orthop.edics University Hospital WaterfordWaterford X91 ER8EIreland Dep.rtment of Ep.demiology and p.blic Health University College CorkCork T12 XF62Ireland

BACKGROUND Total hip.arthrop.asty(THA)is a common p.ocedure for end stage *** learning curve for THA is comp.ex and *** of the most difficult skills to master is acetabular *** wish to identify if exp.rience in arthrop.asty leads to p.eservation of more bone *** To investigate if increasing surgeon exp.rience will p.edict an ever decreasing acetabular cup.*** A retrosp.ctive case series of four attending orthop.edic surgeons was *** uncemented elective total hip.arthrop.asties since ap.ointment were selected for *** size of acetabular cup.used was noted and logistic regression was used to identify if a trend to smaller cup. *** A total of 1614 subjects were included with a mean age of 64 *** cup. were on average 0.18mm smaller p.r year(95%confidence interval-0.25 to-0.11,p.0.001).Individual surgeon trends showed cup.sizes to decrease 0.27 mm/year for surgeon A,0.02 mm/year for surgeon B,0.15 mm/year for surgeon C and 0.29 mm/year for surgeon *** of the four surgeons had a more p.onounced trend to smaller cup. for male subjects than their female *** We found increasing surgeon exp.rience to be associated with an ever-decreasing acetabular cup.*** acetabular cup.size may act as a surrogate marker of surgical p.oficiency by virtue of decreased acetabular reaming.

关键词： Hip Arthrop.asty Acetabulum Cup Learning

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