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Study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties

Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 677-694页

作者： A.S.JOHN B.MAHANTHESH g.LORENZINI Center for Mathematical Needs Department of MathematicsCHRIST(Deemed to be University)Karnataka 560029India School of Mathematical and Statistical Sciences The University of Texas Rio Grande ValleyTexas 78539U.S.A. Department of Engineering and Architecture University of ParmaParma 43124Italy

Cone-disk systems find frequent use such as conical diffusers,medical devices,various rheometric,and viscosimetry *** this study,we investigate the three-dimensional flow of a water-based Ag-Mg O hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid *** the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds's linearized model for variable viscosity and Chiam's model for variable thermal *** single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids,incorporating the experimental *** model is developed as a coupled system of convective-diffusion equations,encompassing the conservation of momentum and the conservation of thermal energy,in conjunction with an incompressibility condition.A self-similar model is developed by the Lie-group scaling transformations,and the subsequent self-similar equations are then solved *** influence of variable fluid parameters on both swirling and non-swirling flow cases is ***,the Nusselt number for the disk surface is *** is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system,while the thermal conductivity parameter has the opposite effect.

关键词： hybrid nanofluid cone-disk system laminar flow variable fluid property Nusselt number

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The great catastrophe: causes of the Permo-Triassic marine mass extinction

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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(g 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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Optimal Control of Service Rates of Discrete-Time(s,Q)Queueing-Inventory Systems with Finite Buffer

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Journal of Systems Science and Systems Engineering 2024年第3期33卷 261-280页

作者： L.Iniya B.Sivakumar g.Arivarignan School of Mathematics Madurai Kamaraj UniversityMaduraiTamilnaduIndia Department of Statistics Manonmaniam Sundaranar UniversityTirunelveliTamilnaduIndia

This article,we develop an optimal policy to control the service rate of a discrete time queueing-inventory system with finite *** customers arrive according to a Bernoulli process and the service time for the customers are *** the buffer size attains its maximum,any arriving new customers are considered to be *** customers are served one by one according to FCFS rule and each customers request random number of *** inventory is replenished according to a(s,Q)inventory policy with geometric lead *** main objectives of this article are to determine the service rates to be employed at each slot so that the long run expected cost rate is minimized for fixed inventory level and fixed buffer size and to minimize the expected waiting time for a fixed inventory level and fixed buffer *** problems are modelled as Markov decision *** establish the existence of a stationary policy and employ linear programming method to find the optimal service *** provide some numerical examples to illustrate the behaviour of the model.

关键词： Queueing-inventory system discrete time batch demand-Markov decision process

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霍夫曼豪夫童话

霍夫曼豪夫童话

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1998年

作者：（德）霍夫曼（德）豪夫

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应用多种遗传标记分析同母异父双胞胎亲子鉴定1例

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法医学杂志 2024年第1期40卷 106-108页

作者：刘光渊上海任直司法鉴定所上海200051

1案例1.1简要案情因诉讼需要,某法院委托本鉴定所对吴某(男,33岁)和双胞胎男孩(吴某郎与吴某易,均为3岁)进行有无亲生血缘关系的鉴定。据法院提供的两子户籍证明及出生证明信息,可明确两者为同母双胞胎。按《亲权鉴定技术规范》(gB/T37... 详细信息

1案例1.1简要案情因诉讼需要,某法院委托本鉴定所对吴某(男,33岁)和双胞胎男孩(吴某郎与吴某易,均为3岁)进行有无亲生血缘关系的鉴定。据法院提供的两子户籍证明及出生证明信息,可明确两者为同母双胞胎。按《亲权鉴定技术规范》(gB/T37223—2018)要求对吴某、吴某郎与吴某易分别采集血样。1.2检验方法1.2.1 DNA提取使用Chelex法提取检材DNA。1.2.2检测过程常染色体STR基因座检测:分别应用Microreader^(TM) 21 ID System和Microreader^(TM) 23sp ID System(北京阅微基因技术股份有限公司)对检材DNA的39个STR基因座和性别基因座复合扩增。

关键词：法医遗传学亲缘关系遗传标记 STR基因座异卵双生半同胞关系指数

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