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The great catastrophe: causes of the Permo-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 Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed 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 rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(ming evidence for rapid 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 productivity collapse volcanic winter

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Nonlinear dynamic modeling of planar moving Timoshenko beam considering non-rigid non-elastic axial effects

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 479-496页

作者： m.AbbASI GAVARI m.R.HOmAEINEZHAD Faculty of mechanical Engineering K.N.Toosi University of TechnologyTehran 19991-43344Iran

Due to the importance of vibration effects on the functional accuracy of mechanical systems,this research aims to develop a precise model of a nonlinearly vibrating single-link mobile flexible *** manipulator consists of an elastic arm,a rotary motor,and a rigid carrier,and undergoes general in-plane rigid body motion along with elastic transverse *** accurately model the elastic behavior,Timoshenko’s beam theory is used to describe the flexible arm,which accounts for rotary inertia and shear deformation *** applying Newton’s second law,the nonlinear governing equations of motion for the manipulator are derived as a coupled system of ordinary differential equations(ODEs)and partial differential equations(PDEs).Then,the assumed mode method(Amm)is used to solve this nonlinear system of governing equations with appropriate shape *** assumed modes can be obtained after solving the characteristic equation of a Timoshenko beam with clamped boundary conditions at one end and an attached mass/inertia at the *** addition,the effect of the transverse vibration of the inextensible arm on its axial behavior is *** the axial rigidity,the effect makes the rigid body dynamics invalid for the axial behavior of the ***,numerical simulations are conducted to evaluate the performance of the developed model,and the results are compared with those obtained by the finite element *** comparison confirms the validity of the proposed dynamic model for the *** to the mentioned features,this model can be reliable for investigating the system’s vibrational behavior and implementing vibration control algorithms.

关键词： planar moving Timoshenko beam non-rigid non-elastic axial effect as-sumed mode method(Amm) nonlinear motion analysis

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Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 543-562页

作者： H.m.FEIZAbAD m.H.YAS Department of mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(bFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** Hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQm)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(bCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for bFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of bFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of bFRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQm)

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Hydrocarbon indication in Rio bonito Formation sandstone:Implication for CO_(2)storage in São Paulo,brazil

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Energy Geoscience 2024年第1期5卷 331-341页

作者： Richardson m.Abraham-A Haline V.Rocha Saulo b.de Oliveira Colombo C.G.Tassinarri Orlando C.da Silva Institute of Energy and Environment University of São PauloSão PauloBrazil Research Centre for Greenhouse Gas Innovation University of São PauloSão PauloBrazil

São Paulo State has witnessed CO_(2)storage-based investigations considering the availability of suitable geologic structures and proximity to primary CO_(2)source sinks related to bioenergy and carbon capture and storage(bECCS)*** current study presents the hydrocarbon viability evaluations and CO_(2)storage prospects,focusing on the sandstone units of the Rio bonito *** objective is to apply petrophysical evaluations with geochemical inputs in predicting future hydrocarbon(gas)production to boost CO_(2)storage within the study *** study used data from eleven wells with associated wireline logs(gamma ray,resistivity,density,neutron,and sonic)to predict potential hydrocarbon accumulation and fluid mobility in the investigated *** samples(shale and carbonate)obtained from depths>200 m within the study location have shown bitumen *** geochemistry data of the Rio bonito Formation shale beds suggest they are potential hydrocarbon source rocks and could have contributed to the gas accumulations within the sandstone *** drilled well data,e.g.,Cb-1-SP and TI-1-SP,show hydrocarbon(gas)presence based on the typical resistivity and the combined neutron-density responses at depths up to 3400 m,indicating the possibility of other hydrocarbon members apart from the heavy oil(bitumen)observed from the near-surface rocks *** the three-dimensional(3-D)model,the free fluid indicator(FFI)is more significant towards the southwest and southeast of the area with deeper depths of occurrence,indicating portions with reasonable hydrocarbon recovery rates and good prospects for CO_(2)injection,circulation and permanent ***,future studies based on contemporary datasets are required to establish the hydrocarbon viability further,foster gas production events,and enhance CO_(2)storage possibilities within the region.

关键词： Paranábasin Hydrocarbon indication Sandstone reservoirs Rio bonito Formation CO_(2)storage Hydrocarbon recovery factor Fluid injection rate

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A Hybrid machine Learning Approach for Improvised QoE in Video Services over 5G Wireless Networks

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Computers, materials & Continua 2024年第3期78卷 3195-3213页

作者： K.b.Ajeyprasaath P.Vetrivelan School of Electronics Engineering Vellore Institute of TechnologyChennaiTamil Nadu600127India

Video streaming applications have grown considerably in recent *** a result,this becomes one of the most significant contributors to global internet *** to recent studies,the telecommunications industry loses millions of dollars due to poor video Quality of Experience(QoE)for *** the standard proposals for standardizing the quality of video streaming over internet service providers(ISPs)is the mean Opinion Score(mOS).However,the accurate finding of QoE by mOS is subjective and laborious,and it varies depending on the user.A fully automated data analytics framework is required to reduce the inter-operator variability characteristic in QoE *** work addresses this concern by suggesting a novel hybrid XGbStackQoE analytical model using a two-level layering *** one combines multiple machine Learning(mL)models via a layer one Hybrid *** mL models at level one are trained using the entire training data *** level two Hybrid XGbStackQoE-model is fitted using the outputs(meta-features)of the layer one mL *** proposed model outperformed the conventional models,with an accuracy improvement of 4 to 5 percent,which is still higher than the current traditional *** proposed framework could significantly improve video QoE accuracy.

关键词： Hybrid XGbStackQoE-model machine learning mOS performance metrics QoE 5G video services

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blockade of Rho-associated kinase prevents inhibition of axon regeneration of peripheral nerves induced by anti-ganglioside antibodies

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Neural Regeneration Research 2024年第4期19卷 895-899页

作者： Andrés berardo Cristian R.bacaglio bárbara b.báez Rubén Sambuelli Kazim A.Sheikh Pablo H.H.Lopez Laboratorio de Neurobiología Instituto de Investigación Médica Mercedes y Martin Ferreyra(INIMEC)-Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET)Universidad Nacional de Córdoba Departamento de Química biológica-Centro de Investigaciones en Química biológica de Córdoba(CIQUIbIC)-Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET) Facultad de Cs.QuímicasUniversidad Nacional de Córdoba Servicio de Anatomía Patológica Clínica Universitaria Reina FabiolaUniversidad Católica de Córdoba Department of Neurology University of Texas Medical School at Houston

Anti-ganglioside antibodies are associated with delayed/poor clinical recovery in Guillain-barrèsyndrome,mostly related to halted axon ***-linking of cell surface gangliosides by anti-ganglioside antibodies triggers inhibition of nerve repair in in vitro and in vivo paradigms of axon *** effects involve the activation of the small GTPase Rho A/ROCK signaling pathways,which negatively modulate growth cone cytoskeleton,similarly to well stablished inhibitors of axon regeneration described so *** aim of this work was to perform a proof of concept study to demonstrate the effectiveness of Y-27632,a selective pharmacological inhibitor of ROCK,in a mouse model of axon regeneration of peripheral nerves,where the passive immunization with a monoclonal antibody targeting gangliosides GD1a and GT1b was previously reported to exert a potent inhibitory effect on regeneration of both myelinated and unmyelinated *** results demonstrate a differential sensitivity of myelinated and unmyelinated axons to the pro-regenerative effect of *** with a total dosage of 9 mg/kg of Y-27632 resulted in a complete prevention of anti-GD1a/GT1b monoclonal antibody-mediated inhibition of axon regeneration of unmyelinated fibers to skin and the functional recovery of mechanical cutaneous *** contrast,the same dose showed toxic effects on the regeneration of myelinated ***,scale down of the dosage of Y-27632 to 5 mg/kg resulted in a significant although not complete recovery of regenerated myelinated axons exposed to anti-GD1a/GT1b monoclonal antibody in the absence of toxicity in animals exposed to only ***,these findings confirm the in vivo participation of Rho A/ROCK signaling pathways in the molecular mechanisms associated with the inhibition of axon regeneration induced by anti-GD1a/GT1b monoclonal *** findings open the possibility of therapeutic pharmacological intervention targeting Rho A/R

关键词： anti-ganglioside antibodies anti-glycan antibodies axon regeneration ganglioside Guillain-barrésyndrome nerve repair ROCK Y-27632

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A rat model of multicompartmental traumatic injury and hemorrhagic shock induces bone marrow dysfunction and profound anemia

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Animal models and Experimental medicine 2024年第3期7卷 367-376页

作者： Lauren S.Kelly Jennifer A.munley Erick E.Pons Kolenkode b.Kannan Elizabeth m.Whitley Letitia E.bible Philip A.Efron Alicia m.mohr Department of Surgery and Sepsis and Critical Illness Research Center University of Florida College of MedicineGainesvilleFloridaUSA Pathogenesis LLCGainesvilleFloridaUSA

background:Severe trauma is associated with systemic inflammation and organ *** rodent trauma models are the mainstay of postinjury research but have been criticized for not fully replicating severe human *** aim of this study was to create a rat model of multicompartmental injury which recreates profound traumatic ***:male Sprague-Dawley rats were subjected to unilateral lung contusion and hemorrhagic shock(LCHS),multicompartmental polytrauma(PT)(unilateral lung contusion,hemorrhagic shock,cecectomy,bifemoral pseudofracture),or na?ve ***,plasma toll-l ike receptor 4(TLR4),hemoglobin,spleen to body weight ratio,bone marrow(bm)erythroid progenitor(CFU-GEmm,bFU-E,and CFU-E)growth,plasma granulocyte colony-stimulating factor(G-CSF)and right lung histologic injury were assessed on day 7,with significance defined as p valuesma resulted in markedly more profound inhibition of weight gain compared to LCHS(p=0.0002)along with elevated plasma TLR4(pmoglobin(pbody weight ratios(p=0.004).both LCHS and PT demonstrated suppression of CFU-E and bFU-E growth compared to naive(pma G-CSF was elevated in PT compared to both na?ve and LCHS(pmonstrated significant histologic right lung injury with poor alveolar wall integrity and interstitial ***:multicompartmental injury as described here establishes a reproducible model of multicompartmental injury with worsened anemia,splenic tissue enlargement,weight loss,and increased inflammatory activity compared to a less severe *** may serve as a more effective model to recreate profound traumatic injury to replicate the human inflammatory response postinjury.

关键词： anemia i nflammation polytrauma pseudofracture shock

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Function and dysfunction of GEmIN5:understanding a novel neurodevelopmental disorder

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Neural Regeneration Research 2024年第11期19卷 2377-2386页

作者： Charles H.Nelson Udai b.Pandey Department of Pediatrics Division of Child NeurologyChildren’s Hospital of PittsburghUniversity of Pittsburgh Medical CenterPittsburghPAUSA Children’s Neuroscience Institute Children’s Hospital of PittsburghUniversity of Pittsburgh Medical CenterPittsburghPAUSA

The recent identification of a neurodevelopmental disorder with cerebellar atrophy and motor dysfunction(NEDCAm)has resulted in an increased interest in GEmIN5,a multifunction RNA-binding *** the largest member of the survival motor neuron complex,GEmIN5 plays a key role in the biogenesis of small nuclear ribonucleoproteins while also exhibiting translational regulatory functions as an independent *** many questions remain regarding both the pathogenesis and pathophysiology of this new disorder,considerable progress has been made in the brief time since its *** this review,we examine GEmIN5 within the context of NEDCAm,focusing on the structure,function,and expression of the protein specifically in regard to the disorder ***,we explore the current animal models of NEDCAm,as well as potential molecular pathways for treatment and future directions of *** review provides a comprehensive overview of recent advances in our understanding of this unique member of the survival motor neuron complex.

关键词： cerebellar atrophy GEmIN5 neurodevelopmental disorder neurological disease SmN complex

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Air purifier or fresh air system?A comparison of energy consumption and cost in urban China residential buildings

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Science China(Technological Sciences) 2024年第9期67卷 2637-2647页

作者： GUO Yong SUN ZhiWei WESCHLER Louise b ZHANG YinPing Department of building Science Tsinghua UniversityBeijing 100084China beijing Key Laboratory of Indoor Air Quality Evaluation and Control Beijing 100084China Independent Researcher Colts Neck 07722NJUSA

Chinese urban residential buildings face serious indoor air quality *** purification systems(e.g.,air purifiers,fresh air systems)that supply fresh air or purify indoor air are widely used in residential buildings to improve indoor air *** the challenges of energy conservation and emission reduction,it is urgent to guide residents on choosing appropriate air purification *** key problem is how to identify the best air purification system with the lowest energy consumption or operating *** of air purification systems have rarely been conducted on the premise that they should deliver air such that the main indoor pollutant concentrations all meet air quality *** ignored in comparisons are the increased filtration resistance caused by dust accumulation on the filter and the cost of filter *** this study,we propose a method to compare residential air purification systems based on energy consumption and total cost,and we provide methods to select air purification systems in China's different climatic *** used a standard two-person bedroom as the example,and determined the most suitable(minimum cost or energy consumption)air purification systems for the capital cities of the provinces in Chinese mainland.

关键词： IAQ fresh air system air purifier energy consumption cost

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Enhanced quantum resources via two distant atom-cavity systems under the influence of atomic dissipation

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Communications in Theoretical Physics 2024年第2期76卷 62-73页

作者： m Setodeh Kheirabady m K Tavassoly m Rafeie E Ghasemian Laser and Optics Group Faculty of PhysicsYazd UniversityYazd 89195-741Iran Department of Electrical Engineering Faculty of Intelligent Systems Engineering and Data SciencePersian Gulf UniversityBushehrIran

Quantum resources such as entanglement and coherence are the holy grail for modern quantum technologies. Although the unwanted environmental effects tackle quantum information processing tasks, suprisingly these key quantum resources may be protected and even enhanced by the implementation of some special hybrid open quantum systems. Here, we aim to show how a dissipative atom-cavity-system can be accomplished to generate enhanced quantum *** do so, we consider a couple of dissipative cavities, where each one contains two effective two-level atoms interacting with a single-mode cavity field. In practical applications, a classical laser field may be applied to drive each atomic subsystem. After driving the system, a bell-state measurement is performed on the output of the system to quantify the entanglement and coherence. The obtained results reveal that the remote entanglement and coherence between the atoms existing inside the two distant cavities are not only enhanced, but can be stabilized, even under the action of dissipation. In contrast, the local entanglement between two atoms inside each dissipative cavity attenuates due to the presence of unwanted environmental ***, the local coherence may show the same behavior as the remote ***, the system provides the steady state entanglement in various interaction regimes,particularly in the strong atom-cavity coupling and with relatively large detuning. more interestingly, our numerical analyses demonstrate that the system may show a memory effect due to the fact that the death and revival of the entanglement take place during the interaction. Our proposed model may find potential applications for the implementation of long distance quantum networks. In particular, it facilitates the distribution of quantum resources between the nodes of large-scale quantum networks for secure communication.

关键词： remote entanglement and coherence atomic dissipation steady state entanglement bell-statemeasurement

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