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Iterative Subregion Correction Preconditioners with Adaptive Tolerance for Problems with Geometrically Localized Stiffness

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Communications on Applied Mathematics and Computation 2024年第2期6卷 811-836页

作者： Michael Franco per-Olof persson Will Pazner Department of Mathematics University of CaliforniaBerkeleyBerkeleyCA 94720-3840USA Fariborz Maseeh Department of Mathematics and Statistics Portland State UniversityPortlandOR 97201USA

We present a class of preconditioners for the linear systems resulting from a finite element or discontinuous Galerkin discretizations of advection-dominated *** preconditioners are designed to treat the case of geometrically localized stiffness,where the convergence rates of iterative methods are degraded in a localized subregion of the *** convergence may be caused by a number of factors,including the mesh size,anisotropy,highly variable coefficients,and more challenging *** approach taken in this work is to correct well-known preconditioners such as the block Jacobi and the block incomplete LU(ILU)with an adaptive inner subregion *** goal of these preconditioners is to reduce the number of costly global iterations by accelerating the convergence in the stiff region by iterating on the less expensive reduced *** tolerance for the inner iteration is adaptively chosen to minimize subregion-local work while guaranteeing global convergence *** present analysis showing that the convergence of these preconditioners,even when combined with an adaptively selected tolerance,is independent of discretization parameters(e.g.,the mesh size and diffusion coefficient)in the *** demonstrate significant performance improvements over black-box preconditioners when applied to several model convection-diffusion ***,we present performance results of several variations of iterative subregion correction preconditioners applied to the Reynolds number 2.25×10^(6)fluid flow over the NACA 0012 airfoil,as well as massively separated flow at 30°angle of attack.

关键词： Subregion correction Nested Krylov Geometrically localized stiffness

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How to fill the biodiversity data gap:Is it better to invest in fieldwork or curation?

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Plant Diversity 2024年第1期46卷 39-48页

作者： Carlos A.Vargas Marius Bottin Tiina Sarkinen James E.Richardson Marcela Celis Boris Villanueva adriana Sanchez Programa de Biología Facultad de Ciencias NaturalesUniversidad del RosarioBogotaD.C.Colombia Subdireccion Científica Jardín Botanico de Bogota“Jose Celestino Mutis”BogotaD.C.Colombia Independent Researcher BogotaD.C.Colombia Tropical Diversity Section Royal Botanic Garden EdinburghUK School of Biological Earth and Environmental SciencesUniversity College CorkCorkIreland Departamento de Química y Biología Universidad del NorteKm.5 Vía Puerto ColombiaArea Metropolitana de Barranquilla 081007Colombia

Data gaps and biases are two important issues that affect the quality of biodiversity information and downstream *** how best to fill existing gaps and account for biases is necessary to improve our current information most *** current main approaches for obtaining and improving data include(1)curation of biological collections,and(2)***,the comparative effectiveness of these approaches in improving biodiversity data remains little *** used the Flora de Bogota project to study the magnitude of change in species richness,spatial coverage,and sample coverage of plant records based on curation versus *** process of curation resulted in a decrease in species richness(synonym and error removal),but it significantly increased the number of records per *** contributed to a slight increase in species richness,via accumulation of new ***,curation led to increases in spatial coverage,species observed by locality,the number of plant records by species,and localities by species compared to ***,curationwas more efficient in producing new information compared to fieldwork,mainly because of the large number of records available in *** recommend intensive curatorial work as the first step in increasing biodiversity data quality and quantity,to identify bias and gaps at the regional scale that can then be targeted with *** stepwise strategy would enable fieldwork to be planned more costeffectively given the limited resources for biodiversity exploration and characterization.

关键词： Colombia Flora de Bogota Sample coverage Species richness Tropical Andes

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鸟类形态特征的同质性比较

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动物学杂志 2024年第3期59卷 321-336页

作者：郑雪星 per G.P.Ericson 屈延华中国科学技术大学生命科学与医学部合肥230026 中国科学院动物研究所动物进化与系统学院重点实验室北京100010 瑞典自然历史博物馆瑞典斯德哥尔摩50007

鸟类作为脊椎动物中的主要类群之一,其内部演化关系一直是动物学研究的重点。形态特征及分子特征在推断鸟类内部类群间的系统发育关系时被广泛应用,但长久以来受制于同质性的影响,不同形态特征难以得到一致的系统发育关系。随着基因组... 详细信息

鸟类作为脊椎动物中的主要类群之一,其内部演化关系一直是动物学研究的重点。形态特征及分子特征在推断鸟类内部类群间的系统发育关系时被广泛应用,但长久以来受制于同质性的影响,不同形态特征难以得到一致的系统发育关系。随着基因组测序技术及分析方法的快速发展,基于大量DNA序列数据所建的物种树成为领域内普遍认可的鸟类系统发育关系。在此基础之上,重新挖掘形态特征的研究价值成为可能。本研究基于Prum发表于2015年的鸟类科级水平系统发育树,比较了不同形态特征同质性水平的差异,讨论了形态特征对于提高分子特征系统发育信号及分子树支持率的作用。研究发现,不同种类形态特征的同质性水平存在显著的差异,以一致性指数为标准,杂项特征(包括神经、肌腱及肠道的特征)的得分显著高于骨学特征和肌学特征(P<0.01),颅骨特征的得分显著高于非颅骨、躯干及腿部特征的得分(P<0.05);加入形态特征能够显著提高分子特征的系统发育信号(P<0.05),也提高了分子树的支持率。综上所述,不同的形态特征在同质性水平的得分上具有显著差异,在分子特征上加入形态特征既能够提高分子特征的系统发育信号,也能够提高分子树的支持率。

关键词：形态特征同质性水平一致性指数系统发育信号支持率

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On the potential of using ensemble learning algorithm to approach the partitioning coefficient(k)value in Scheil-Gulliver equation

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Materials Genome Engineering Advances 2024年第3期2卷 48-58页

作者： Ziyu Li He Tan Anders E.W.Jarfors Jacob Steggo Lucia Lattanzi per Jansson Comptech i Skillingaryd AB SkillingarydSweden Department of Materials and Manufacturing School of EngineeringJönköping UniversityJönköpingSweden Department of Computing School of EngineeringJönköping UniversityJönköpingSweden

The Scheil-Gulliver equation is essential for assessing solid fractions during alloy solidification in materials *** the prevalent use of the Calculation of Phase Diagrams(CALPHAD)method,its computational intensity and time are limiting the simulation ***,Artificial Intelligence has emerged as a potent tool in materials science,offering robust and reliable predictive modeling *** study introduces an ensemble-based method that has the potential to enhance the prediction of the partitioning coefficient(k)in the Scheil equation by inputting various alloy *** findings demonstrate that this approach can predict the temperature and solid fraction at the eutectic temperature with an accuracy exceeding 90%,while the accuracy for k prediction surpasses 70%.Additionally,a case study on a commercial alloy revealed that the model's predictions are within a 5℃deviation from experimental results,and the predicted solid fraction at the eutectic temperature is within a 15%difference of the values obtained from the CALPHAD model.

关键词： AI application partitioning coefficient scheil-gulliver equation solidification

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May Traditional Chinese Medicine Reduce the Risk of Developing Rheumatoid Arthritis?An One-armed Prospective Study

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Clinical Complementary Medicine and Pharmacology 2024年第1期4卷 10-18页

作者： Kaixin Gao Qi Liang Dongyun Li Chuanning Li Maojie Wang Xiumin Chen Qingchun Huang Zehuai Wen per-Johan Jakobsson Runyue Huang The Second Affiliated Hospital of Guangzhou University of Chinese Medicine(Guangdong Provincial Hospital of Chinese Medicine) Guangzhou 510006GuangdongChina The Second Clinical Medical College Guangzhou University of Chinese MedicineGuangzhou 510006GuangdongChina State Key Laboratory of Dampness Syndrome of Chinese Medicine The Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou 510120GuangdongChina Guangdong Provincial Key Laboratory of Chinese Medicine for Prevention and Treatment of Refractory Chronic Diseases Guangzhou 510403GuangdongChina Guangdong-Hong Kong-Macao Joint Lab on Chinese Medicine and Immune Disease Research Guangzhou 510000GuangdongChina The key unit of methodology of clinical research The Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou 510000GuangdongChina Rheumatology Unit Department of Medicine SolnaKarolinska InstituteKarolinska University HospitalStockholm 17177Sweden Department of Doctor-Patient Relationship The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510630GuangdongChina

Background:Rheumatoid arthritis(RA)is a worldwide public health *** and prevention before the onset of rheumatic diseases is a new direction in current ***:The aim of this study was to evaluate the potential and feasibility of traditional Chinese medicine(TCM)in the prevention of ***:This was a single-armed prospective clinical *** participants were recruited from a single center in Guangdong,*** who were tested positive for anti-cyclic citrullinated peptide antibody(anti-CCP)and/or rheumatoid factor(RF),had no synovitis and never been treated with disease-modifying anti-rheumatic drugs(DMARDs),were enrolled to take the Huayu-Qiangshen-Tongbi(HQT)decoction orally twice daily,200 mL each time for 24 *** outcome was the proportion of patients who met 2010 ACR(American College of Rheumatology)/EULAR(European League Against Rheumatism)classification criteria of RA during *** outcomes included levels of anti-CCP,RF,erythrocyte sedimentation rate(ESR),C-reactive protein(CRP),assessment of signs and symptoms,and radiographic progression by magnetic resonance imaging(MRI).Results:19 individuals were enrolled in the study,4 of which withdrew because of the epidemic of *** the observation period,3 individuals(20%)developed RA and they had longer morning stiffness(P=0.009)and more obvious synovial enhancement in MRI(P=0.041)at baseline when compared with those who did not develop *** 24 weeks of intervention,there were improvements in 28-swollen joint count(SJC28)(P=0.046),Visual Analog Scale(VAS)(P=0.019),Patient’s Global Assessment(PtGA)(P=0.019)and Physician’s Global Assessment(PGA)(P=0.031),but no statistical significance was observed in the levels of anti-CCP,RF,ESR,CRP,morning stiffness,28-tender joint count(TJC28),Health Assessment Questionnaire(HAQ)and magnetic resonance imaging(MRI)analysis(P>0.05).Conclusion:The HQT formula is safe and could improve joint symptoms and s

关键词： Rheumatoid arthritis(RA) Prevention Traditional Chinese medicine(TCM) Huayu-Qiangshen-Tongbi decoction(HQT) Clinical trial

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湿型砂铸铝:打开新的视角

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铸造 2024年第1期73卷 135-138页

作者： per Larsen Tim J.Baron 陈之伟(译) 刘溢(译) DISA Industries A/S 迪砂中国

许多汽车零部件已经用铸铝件替代以前的铸铁件。铸铝件在电动汽车的过渡中至关重要。随着汽车行业的成功转型,大批量的新型电动汽车传动系统铝部件应运而生,如电机壳和机盖。众所周知,湿型砂工艺能高效,可低成本生产出高质量的铸铁件。... 详细信息

许多汽车零部件已经用铸铝件替代以前的铸铁件。铸铝件在电动汽车的过渡中至关重要。随着汽车行业的成功转型,大批量的新型电动汽车传动系统铝部件应运而生,如电机壳和机盖。众所周知,湿型砂工艺能高效,可低成本生产出高质量的铸铁件。随着全球对铸铝件的需求不断上升,降低成本的压力不断加大,越来越多的铸造厂和制造商开始探索湿型砂生产铸铝件的运用。铸铁厂用湿型砂生产的优势成功转移到铸铝件,带来低成本、快速成形和灵活性等优点。

关键词：铸铝件湿型砂铸铁件低成本生产快速成形汽车零部件汽车传动系统电机壳

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Oxidized organic molecules in the tropical free troposphere over Amazonia

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National Science Review 2024年第1期11卷 174-184页

作者： Qiaozhi Zha Diego Aliaga Radovan Krejci Victoria A.Sinclair Cheng Wu Giancarlo Ciarelli Wiebke Scholz Liine Heikkinen Eva Partoll Yvette Gramlich Wei Huang Markus Leiminger Joonas Enroth Otso per?kyl? Runlong Cai Xuemeng Chen Alkuin Maximilian Koenig Fernando Velarde Isabel Moreno Tuukka Pet?j? Paulo Artaxo Paolo Laj Armin Hansel Samara Carbone Markku Kulmala Marcos Andrade Douglas Worsnop Claudia Mohr Federico Bianchi Institute for Atmospheric and Earth System Research/Physics University of Helsinki Joint International Research Laboratory of Atmospheric and Earth System Sciences Nanjing University Department of Environmental Science & Bolin Centre for Climate Research Stockholm University Department of Chemistry and Molecular Biology University of Gothenburg Institute for Ion and Applied Physics University of Innsbruck Ionicon Analytik GmbH Laboratory for Atmospheric Physics Institute for Physics Research Universidad Mayor de San Andrés Institute of Physics University of Sao Paulo Institute for Geosciences and Environmental Research (IGE) University of Grenoble Alpes Agrarian Sciences Institute Federal University of Uberl?ndia Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Department of Atmospheric and Oceanic Sciences University of Maryland Aerodyne Research Inc. Department of Environmental System Science ETH Zürich Switzerland and Laboratory of Atmospheric Chemistry Paul Scherrer Institute

New particle formation(NPF) in the tropical free troposphere(FT) is a globally important source of cloud condensation nuclei, affecting cloud properties and climate. Oxidized organic molecules(OOMs)produced from biogenic volatile organic compounds are believed to contribute to aerosol formation in the tropical FT, but without direct chemical observations. We performed in situ molecular-level OOMs measurements at the Bolivian station Chacaltaya at 5240 m above sea level, on the western edge of Amazonia. For the first time, we demonstrate the presence of OOMs, mainly with 4–5 carbon atoms, in both gas-phase and particle-phase(in terms of mass contribution) measurements in tropical FT air from Amazonia. These observations, combined with air mass history analyses, indicate that the observed OOMs are linked to isoprene emitted from the rainforests hundreds of kilometers away. Based on particle-phase measurements, we find that these compounds can contribute to NPF, at least the growth of newly formed nanoparticles, in the tropical FT on a continental scale. Thus, our study is a fundamental and significant step in understanding the aerosol formation process in the tropical FT.

关键词： oxidized organic molecules tropical aerosol formation Amazon free troposphere

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A comparative genomic framework for the fish-tetrapod transition

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Science China(Life Sciences) 2021年第4期64卷 664-666页

作者： per Erik Ahlberg Department of Organismal Biology Uppsala University75236 UppsalaSweden

The evolution of tetrapods(land vertebrates)from lobe-finned fishes,nearly 400 million years ago,was a hugely important *** one thing,if these ancient fishes had not found a way to adapt to life out of the water,we humans would not *** investigate this event we can look at the fossil record,but that only tells us about changes in the skeleton.

关键词： skeleton record fish

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Comparative analysis of planted and unplanted controls for assessment of rhizosphere priming effect

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Pedosphere 2022年第6期32卷 884-892页

作者： Jian LI per BENGTSON Department of Biology Microbial Ecology GroupLund UniversitySölvegatan 37Lund 22362(Sweden) Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of Sciences1799 Jimei RoadXiamen 361021(China)

The rhizosphere priming effect(RPE)is increasingly being considered to be an important regulator of soil organic matter(SOM)decomposition and nutrient turnover,with potential importance for the global CO_(2) *** a result,studies on the RPE have rapidly increased in number over the last few *** of these experiments have been performed using unplanted soil as the control,which could potentially lead to incorrect assessment of the ***,we performed a greenhouse experiment to investigate how the choice of control(i.e.,unplanted control and planted control)influenced the quantification of RPE on SOM decomposition and gross nitrogen(N)mineralization,and to link this to differences in microbial and abiotic soil properties between the two *** the planted control,planted seedlings were cut at soil surface 5 d before measurement of the *** RPE on SOM decomposition was positive in pine soil and almost 2-fold higher when calculated from the planted control than from the unplanted *** spruce soil,a negative RPE on SOM decomposition was found when calculated from the planted control,while the RPE was positive when calculated from the unplanted *** RPE on gross N mineralization was found when calculated from the planted control,while a positive RPE of more than 100%was found when calculated from the unplanted *** microbial biomass and growth rate were lower,while the inorganic N content was higher in the unplanted control than in the planted *** microbial community composition and potential enzyme activity in the planted treatment and planted control were similar,but they differed significantly from those in the unplanted *** results showed that the RPE varied widely depending on the choice of control;thus,we suggest that a planted control,in which the aboveground plant parts are removed only a few days before the measurement of RPE,should be used as the control when elucidating the RPE on belowground C and N

关键词： enzyme activity gross nitrogen mineralization microbial community composition nitrogen availability soil organic matter decomposition

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Spinal and supraspinal control of motor function during maximal eccentric muscle contraction:Effects of resistance training

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Journal of Sport and Health Science 2018年第3期7卷 282-293页

作者： per Aagaard Department of Sports Science and Clinical Biomechanics University of Southern Denmark

Neuromuscular activity is suppressed during maximal eccentric(ECC)muscle contraction in untrained subjects owing to attenuated levels of central activation and reduced spinal motor neuron(MN)excitability indicated by reduced electromyography signal amplitude,diminished evoked H-reflex responses,increased autogenic MN inhibition,and decreased excitability in descending corticospinal motor *** ECC muscle force recorded during maximal voluntary contraction can be increased by superimposed electrical muscle stimulation only in untrained individuals and not in trained strength athletes,indicating that the suppression in MN activation is modifiable by resistance *** support of this notion,maximum ECC muscle strength can be increased by use of heavy-load resistance training owing to a removed or diminished suppression in neuromuscular ***(weeks to months)of heavy-load resistance training results in increased H-reflex and V-wave responses during maximal ECC muscle actions along with marked gains in maximal ECC muscle strength,indicating increased excitability of spinal MNs,decreased presynaptic and/or postsynaptic MN inhibition,and elevated descending motor ***,the use of supramaximal ECC resistance training can lead to selectively elevated V-wave responses during maximal ECC contraction,demonstrating that adaptive changes in spinal circuitry function and/or gains in descending motor drive can be achieved during maximal ECC contraction in response to heavy-load resistance training.

关键词： Corticospinal excitability Eccentric muscle contraction H-reflex Neuromuscular plasticity Resistance training V-wave

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