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粉末冶金Al-5.6Zn-2Mg合金在热压缩过程中加工硬化特性及本构模型的比较

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journal of Central South University 2024年第2期31卷 346-368页

作者： KATIKA Harikrishna DAMODA r.K. DAVIDSON M.j. SEETHArAM r. KASAGANI Veera Venkata Nagaraju Department of Mechanical Engineering National Institute of TechnologyWarangal 506004India Department of Mechanical Engineering The Indian Institute of Information Technology Design and ManufacturingKurnool 518007India

在300~5000℃、应变速率为0.1~0.0001 s−1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σ_(c)(ε_(c))l以及关键特征σ_(c)(ε_(c))l、σ_(p)(ε_(p))和σ_(ss)与Z系数之间的... 详细信息

在300~5000℃、应变速率为0.1~0.0001 s−1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σ_(c)(ε_(c))l以及关键特征σ_(c)(ε_(c))l、σ_(p)(ε_(p))和σ_(ss)与Z系数之间的相关性。使用了四个本构模型,Arrhenius模型、改进的johnson-Cook模型(MjC)、改进的Zerilli-Armstrong模型(MZA)和开发的人工神经网络(ANN)。结果表明,ANN型模型和Arrhenius模型的相对误差的绝对平均值最低,分别为0.486%和3.36%,MZA型模型和MjC型模型的相对误差的绝对平均值较高,分别为8.84%和3.93%。由于Arrhenius模型能够处理各种因素之间的非线性关系,因此它被认为是最合适的预测模型,但在材料性质未知或实验数据有限的情况下,MjC模型可能是一种更简单的替代方法。MZA模型不适合估计热压缩时的流变应力。此外,训练最好的神经网络模型的预测性能最好,相对误差的绝对平均值为0.486%,r值为0.99。

关键词：加工硬化速率曲线本构建模热压缩 EBSD分析流变曲线

Gene therapy for spinal muscular atrophy:perspectives on the possibility of optimizing SMN1 delivery to correct all neurological and systemic perturbations

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Neural regeneration research 2025年第7期20卷 2011-2012页

作者： Sharon j.Brown rafael j.Yáñez-Muñoz Heidi r.Fuller School of Pharmacy and Bioengineering Keele UniversityKeeleUK Wolfson Center for Inherited Neuromuscular Disease TORCH BuildingRJAH Orthopaedic HospitalOswestryUK *** Center of Gene and Cell TherapyDepartment of Biological SciencesSchool of Life Sciences and the EnvironmentRoyal Holloway University of LondonEghamUK

Spinal muscular atrophy(SMA)is a genetic condition that results in selective lower motor neuron loss with concomitant muscle weakness and *** genetic cause of SMA was understood in 1995 when loss or impairment of the survival motor neuron 1(SMN1)gene was identified as the main contributing factor(Lefebvre et al.,1995).This,in combination with the discovery that humans have a“back-up”gene,SMN2,which can produce low levels(approximately 10%)of the full-length functional SMN protein,has led to the generation of SMA-specific gene *** was traditionally classified according to age of symptom onset and developmental milestones achieved,with life expectancy and severity varying between ***,SMN2 copy number is used as a proxy for the prediction of disease severity,with higher SMN2 copy number typically being associated with reduced severity of SMA,although this relationship is not absolute:some individuals with low SMN2 copy number have less severe SMA phenotypes and vice ***,the etiology of SMA is further complicated by other factors,such as non-typical nucleotide variants and SMN2-independent modifiers of disease severity.

关键词： atrophy traditionally absolute

A detailed comparison of the composition of(rE)-Ba-Cu-O-Ag bulk superconductors

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Superconductivity 2024年第1期9卷 87-94页

作者： j.V.j.Congreve Y.Shi A.r.Dennis H.Druiff N.C.Tutt D.A.Cardwell j.H.Durrell Department of Engineering University of CambridgeCambridgeUK

The homogeneity of the microstructure and composition are critical in determining the properties of rare earthbarium‐cuprate,single grain bulk superconductors[(rE)BCO].The magnitude of the trapped magnetic field achieveable in these technologically important materials,in particular,is influenced heavily by the size and distribution of(rE)_(2)BaCuO_(x)(rE‐211)flux pinning inclusions in the bulk microstructure,whereas the size and distribution of silver agglomerates present within the bulk superconducting matrix correlate directly with improved mechanical *** careful engineering,these materials have significant potential for application in range of devices related to energy storage,medicine,electro‐magnetic machinery and microelectronic *** of(rE)BCO bulk superconductors typically involves heating a powder compact above its peritectic decomposition temperature followed by slow cooling to facilitate the growth of a single ***(rE)BCO composition has a different peritectic temperature and growth rate,which,therefore,necessitates different requirements in the heating *** fabrication temperature and growth rate,for example,may have an effect on the rE‐211 and silver distribution,which may,in turn,affect the superconducting properties of the resulting single *** this work we compare the distributions of silver and rE‐211 in the single grain microstructures of YBCOAg,GdBCO‐Ag,EuBCO‐Ag and SmBCO‐Ag bulk superconductors using optical microscopy,scanning electron microscopy and energy dispersive X‐ray *** observe that the distributions are very similar along both the a/b‐axis and c‐axis of these *** suggests that factors other than the maximum temperature used to achieve peritectic decomposition and the rate of single grain growth are particularly influential in determining the properties of the as‐processed samples in the top seeded melt growth *** observation demonstrates there is freedom to us

关键词： YBCO‐Ag GdBCO‐Ag SmBCO‐Ag EuBCO‐Ag Composition Bulk superconductor

Storing Freshwater Versus Storing Electricity in Power Systems with High Freshwater Electric Demand

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journal of Modern Power Systems and Clean Energy 2024年第2期12卷 323-333页

作者： Mubarak j.Al-Mubarak Antonio j.Conejo Department of Electrical and Computer Engineering The Ohio State UniversityColumbusOHUSA Department of Electrical Engineering Kuwait UniversityP.O.Box 5969Safat 13060Kuwait Department of Integrated Systems Engineering and the Department of Electrical and Computer Engineering The Ohio State UniversityColumbusOH 43210USA IEEE

We consider a power system whose electric demand pertaining to freshwater production is high(high freshwater electric demand),as in the Middle East,and investigate the tradeoff of storing freshwater in tanks versus storing electricity in batteries at the day-ahead operation *** storing freshwater and storing electricity increase the actual electric demand at valley hours and decrease it at peak hours,which is generally beneficial in term of cost and ***,to what extent?We analyze this question considering three power systems with different generation-mix configurations,i.e.,a thermal-dominated mix,a renewable-dominated one,and a fully renewable *** generation-mix configurations are inspired by how power systems may evolve in different countries in the Middle *** production uncertainty is compactly modeled using chance *** draw conclusions on how both storage facilities(freshwater and electricity)complement each other to render an optimal operation of the power system.

关键词： Power system operation freshwater production and transportation coordination day-ahead scheduling

Muscle strength deficits are associated with low bone mineral density in young pediatric cancer survivors:The iBoneFIT project

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journal of Sport and Health Science 2024年第3期13卷 419-427页

作者： Andres Marmol-Perez jose j.Gil-Cosano Esther Ubago-Guisado Francisco j.Llorente-Cantarero juan Francisco Pascual-Gázquez Kirsten K.Ness Vicente Martinez-Vizcaino jonatan r.ruiz Luis Gracia-Marco Department of Physical Education and Sports Faculty of Sport SciencesSport and Health University Research Institute(iMUDS)University of GranadaGranada 18011Spain Department of Epidemiology and Cancer Control St.Jude Children's Research HospitalMemphisTN 38105USA Department of Communication and Education Loyola University AndalusiaSeville 41704Spain Biosanitary research Institute ibs.GranadaGranada 18012Spain Maimonides Biomedical research Institute of Cordoba(IMIBIC) Cordoba 14004Spain CIBErOBN Biomedical Research Networking Center for Physiopathology of Obesity and NutritionCarlos III Health InstituteMadrid 28029Spain Department of Specific Didactics Faculty of EducationUniversity of CordobaCordoba 14071Spain Pediatric and adolescent hematology and oncology service Pediatrics and Pediatric Surgery Clinical Management UnitVirgen de las Nieves University HospitalGranada 18014Spain Health and Social research Center Universidad de Castilla-La ManchaCuenca 13001Spain

Background Pediatric cancer survivors are at increased risk of muscle weakness and low areal bone mineral density(aBMD).However,the prevalence of muscle strength deficits is not well documented,and the associations of muscle strength with aBMD are unknown in this ***,this study aimed to investigate the prevalence of upper-and lower-body muscle strength deficits and to examine the associations of upper-and lower-body muscle strength with age-,sex,and race-specific aBMD Z-scores at the total body,total hip,femoral neck,and lumbar *** This cross-sectional study included 116 pediatric cancer survivors(12.1±3.3 years old,mean±SD;42.2%female).Upper-and lower-body muscle strength were assessed by handgrip and standing long jump test,***‑energy X‑ray absorptiometry was used to measure aBMD(g/cm2).Associations between muscle strength and aBMD were evaluated in multivariable linear regression *** regression was used to evaluate the contribution of muscle strength(1-decile lower)to the odds of having low aBMD(Z-score≤1.0).All analyses were adjusted for time from treatment completion,radiotherapy exposure,and body mass *** More than one-half of survivors were within the 2 lowest deciles for upper-(56.9%)and lower-body muscle strength(60.0%)in comparison to age-and sex-specific reference *** strength deficits were associated with lower aBMD Z-scores at all sites(B=0.133–0.258,p=0.001–0.032).Each 1-decile lower in upper-body muscle strength was associated with 30%–95%higher odds of having low aBMD Z-scores at all *** 1-decile lower in lower-body muscle strength was associated with 35%–70%higher odds of having low aBMD Z-scores at total body,total hip,and femoral *** Muscle strength deficits are prevalent in young pediatric cancer survivors,and such deficits are associated with lower aBMD Z-scores at all *** results suggest that interventions designed to improve muscle strength in t

关键词： Bone health Childhood cancer DXA Lean mass resistance training

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Current Zoology 2024年第1期70卷 1-12页

作者： Lucia V.Sommaro juan j.Martinez Marina B.Chiappero Andrea r.Steinmann Cristina N.Gardenal joséW.Priotto Laboratorio de Ecologia Evolutiva y Biogeografia Instituto de Ecorregiones Andinas(INECoA)Universidad Nacional de Jujuy-Consejo Nacional de Investigaciones Cientificas y Tecnicas(CONICET)San Salvador de JujuyJujuyArgentina Instituto de Diversidad y Ecologia Animal(IDEA) Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET)and Universidad Nacionalde CordobaCordobaArgentina Catedra de Genética de Poblaciones y Evolucion Facultad de Ciencias ExactasFisicas y NaturalesUniversidad Nacional de CordobaCordobaArgentina Grupo de Investigaciones en Ecologia Poblacional y Comportamental(GIEPCO) Instituto de Ciencias de la TierraBiodiversidad y Ambiente(ICBiA)Universidad Nacional de Rio Cuarto-Consejo Nacional de Investigaciones Cientificas y Técnicas(CONICET)Rio CuartoCordobaArgentina

The sex-biased dispersal and kinship dynamics are important factors shaping the spatial distribution of individuals and are key parameters affecting a variety of ecological and evolutionary ***,we studied the spatial distribution of related individuals within a population of corn mice Calomys musculinus in a seasonal cycle to infer dispersal *** sampling was carried out from spring 2005 to winter 2006 in field borders of intensively managed *** data from 346 individuals with 9 microsatellites showed spatial genetic structure was weak for males,but not for *** results indicate a complex spatial kinship dynamic of related females across all ***,contrary to our expectations,dispersal distances decrease with the increase of the population ***,male dispersal distances were greater when population abundance increased and thus the availability of active *** disperse greater distances to mate and sire offspring with distant females as a possible inbreeding avoidance *** study shows that *** is capable of much greater scattering distances than previously reported and that dispersal occurs fluidly and without barriers across the *** indirect benefit of dispersal on individual fitness could be related to relaxing the competition in the natal area and increasing the mating *** study highlights the value of combining genetic relatedness,fieldwork observations,and behavioral data to estimate dispersal at a fine geographical scale.

关键词： dispersal distances kinship dynamics microsatellite small mammals spatial autocorrelation

Obstructive sleep apnea:Overlooked comorbidity in patients with diabetes

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World journal of Diabetes 2024年第7期15卷 1448-1460页

作者： Eric D Tenda joshua Henrina jin H Cha Muhammad r Triono Ersananda A Putri Dahliana j Aristy Dicky L Tahapary Division of respirology and Critical Care Department of Internal MedicineFaculty of Medicine Universitas Indonesia-Cipto Mangunkusumo HospitalDKI JakartaJakarta Pusat 10430Indonesia Head of research Group Artificial Intelligence and Digital Health Indonesian Medical Education and Research InstituteFaculty of Medicine University of IndonesiaDKI JakartaJakarta Pusat 10430Indonesia Division of Endocrinology Metabolism and DiabetesDepartment of Internal MedicineFaculty of Medicine Universitas Indonesia-Cipto Mangunkusumo HospitalDKI JakartaJakarta Pusat 10430Indonesia

In this review article,we explore the interplay between obstructive sleep apnea(OSA)and type 2 diabetes mellitus(T2DM),highlighting a significant yet often overlooked *** delve into the pathophysiological links between OSA and diabetes,specifically how OSA exacerbates insulin resistance and disrupts glucose *** research examines the prevalence of OSA in diabetic patients and its role in worsening diabetes-related *** the importance of comprehensive management,including weight control and positive airway pressure therapy,the study advocates integrated approaches to improve outcomes for patients with T2DM and *** review underscores the necessity of recognizing and addressing OSA in diabetes care to ensure more effective treatment and better patient outcomes.

关键词： Obstructive sleep apnea Type 2 diabetes mellitus Macrovascular Microvascular Weight loss Positive airway pressure

Graphene-calcium carbonate coating to improve the degradation resistance and mechanical integrity of a biodegradable implant

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journal of Magnesium and Alloys 2024年第1期12卷 394-404页

作者： Lokesh Choudhary Parama Chakraborty Banerjee r.K.Singh raman Derrek E.Lobo Christopher D.Easton Mainak Majumder Frank Witte j.r. F.Löffler Department of Mechanical and Aerospace Engineering Monash UniversityClayton CampusMelbourneVIC 3800Australia Department of Chemical and Biological Engineering Monash UniversityClayton CampusMelbourneVIC 3800Australia Nanoscale Science and Engineering Laboratory(NSEL) Bldg 37Monash UniversityClayton CampusMelbourneVIC 3800Australia CSIrO Materials Science and Engineering Bayview AvenueClaytonVIC 3168Australia julius Wolff Institute and Berlin Brandenburg Center for regenerative Therapies Charité–Universitätsmedizin BerlinAugustenburger Platz 113353 BerlinGermany Laboratory of Metal Physics and Technology Department of MaterialsETH Zurich8093 ZurichSwitzerland

Biodegradable implants are critical for regenerative orthopaedic procedures,but they may suffer from too fast corrosion in human-body *** necessitates the synthesis of a suitable coating that may improve the corrosion resistance of these implants without compromising their mechanical *** this study,an AZ91 magnesium alloy,as a representative for a biodegradable Mg implant material,was modified with a thin reduced graphene oxide(rGO)-calcium carbonate(CaCO_(3))composite *** analytical and in-vitro electrochemical characterization reveals that this coating significantly improves the corrosion resistance and mechanical integrity,and thus has the potential to greatly extend the related application field.

关键词： Graphene coating Biodegradable implant Hydroxyapatite Corrosion Magnesium alloy

Lax-Oleinik-Type Formulas and Efficient Algorithms for Certain High-Dimensional Optimal Control Problems

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1428-1471页

作者： Paula Chen j.r.me Darbon Tingwei Meng Division of Applied Mathematics Brown UniversityProvidenceRIUSA Department of Mathematics UCLALos AngelesCAUSA

Two of the main challenges in optimal control are solving problems with state-dependent running costs and developing efficient numerical solvers that are computationally tractable in high *** this paper,we provide analytical solutions to certain optimal control problems whose running cost depends on the state variable and with constraints on the *** also provide Lax-Oleinik-type representation formulas for the corresponding Hamilton-jacobi partial differential equations with state-dependent ***,we present an efficient,grid-free numerical solver based on our representation formulas,which is shown to scale linearly with the state dimension,and thus,to overcome the curse of *** existing optimization methods and the min-plus technique,we extend our numerical solvers to address more general classes of convex and nonconvex initial *** demonstrate the capabilities of our numerical solvers using implementations on a central processing unit(CPU)and a field-programmable gate array(FPGA).In several cases,our FPGA implementation obtains over a 10 times speedup compared to the CPU,which demonstrates the promising performance boosts FPGAs can *** numerical results show that our solvers have the potential to serve as a building block for solving broader classes of high-dimensional optimal control problems in real-time.

关键词： Optimal control Hamilton-jacobi partial differential equations Grid-free numerical methods High dimensions Field-programmable gate arrays(FPGAs)