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Noise color influence on escape times in nonlinear oscillators-experimental and numerical results

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Theoretical & Applied Mechanics Letters 2023年第2期13卷 149-158页

作者： thomas Breunung Balakumar Balachandran Department of Mechanical Engineering University of MarylandCollege ParkMD 20742United States

The interplay between noise and nonlinearites can lead to escape dynamics.Associated nonlinear phe-nomena have been observed in various applications ranging from climatology to biology and engineering.For reasons of computational ease,in most studies,Gaussian white noise is used.However,this noise model is not physical due to the associated infinite energy content.Here,the authors present extensive experimental investigations and numerical simulations conducted to examine the impact of noise color on escape times in nonlinear oscillators.With a careful parameterization of the numerical simulations,the authors are able to make quantitative comparisons with experimental results.Through the experi-ments and simulations,it is illustrated that the noise color can drastically influence escape times and escape probability.

关键词： Colored noise Non-Gaussian excitation Experiments Escape times

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基础设施地震预警系统的范围分析

世界地震译丛 2015年第5期46卷 432-442页

作者： Theresa J.Brown Andjelka Kelic Kevin L. Stamber Nancy S.Brodsky Eric D.Vugrin thomas F.Corbet Jr. William E.Fogleman Sharon L.O'connor 谢辉李青梅宁夏回族自治区地震局

提供了评价假想地震预警系统,降低潜在灾害风险值的范围研究的成果。本研究根据的是对人口和基础设施降低灾害风险可采取的行动、采取每个行动需要多少时间和给定所采取行动的性质情况下虚报的潜在后果的分析。范围分析结果表明,可通过... 详细信息

提供了评价假想地震预警系统,降低潜在灾害风险值的范围研究的成果。本研究根据的是对人口和基础设施降低灾害风险可采取的行动、采取每个行动需要多少时间和给定所采取行动的性质情况下虚报的潜在后果的分析。范围分析结果表明,可通过改进现有的事件通知系统、对通知的个体响应和为当地规划绘制并利用更详细灾害风险图来降低灾害风险。根据地质条件和过程的现有知识所制定的详细地图和培训计划,将减少灾害风险分析结果部分的不确定性。地震的发震时间、震级和震中位置的不确定性以及虚报的潜在影响将对预警系统的价值提出重大的挑战。

关键词：地震预警系统基础设施潜在灾害灾害风险不确定性发震时间通知系统地质条件

Regular and p-Regular Orbits of Solvable Linear Groups,Ⅱ

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代数集刊:英文版 2023年第2期30卷 301-304页

作者： thomas Michael Keller Yong Yang Department of Mathematics Texas State UniversitySan MarcosTX 78666USA College of Science China Three Gorges University Three Gorges Mathematical Research CenterYichangHubei 443002China Department of MathematicsTexas State UniversitySan MarcosTX 78666USA

Let V be a faithful G-module for a finite group G and let p be a prime dividing IG].An orbit yG for the action of G on V is regular if|v^(G)|=|G:C_(G)(v)]=|G|,and is p-regular if|v^(G)|_(p)=|G:C_(G)(v)|_(p)=|G|_(p).In this note,we study two questions,one by the authors and one by Isaacs,related to the p-regular orbits and regular orbits of the linear group actions.

关键词： regular orbits solvable linear groups group action

Effects of the FIFA 11+program on performance,biomechanical measures,and physiological responses:A systematic review

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Journal of Sport and Health Science 2023年第2期12卷 226-235页

作者： Mojtaba Asgari Bahareh Nazari Mario Bizzini thomas Jaitner Institute for Sport and Sports Science TU Dortmund UniversityDortmund 44221Germany Faculty of Physical Education and Sports Science University of TehranKish Island branchKish Island 79416Iran Human Performance Lab Schulthess Clinic LengghaldeZürich 8008Switzerland

Background:The side effects of the FIFA 11+program on performance have not been generally reviewed.The objective of this study was to synthesize the literature on the effects of the 11+on players’performance.Methods:Five online databases(PubMed,Scopus,ScienceDirect,Springer,and Google Scholar)were searched(from April 2006 to March 2022)using predefined keywords and sub-keywords.The potential references were primarily recorded through Endnote and imported to Covidence.Out of the 123 references screened by 2 blinded researchers through the software,59 full texts were assessed for eligibility,33 of which were ultimately included.The quality of the studies and the risk of bias were then assessed.Study ID,title,place,aim,design,start/end dates,population description,study criteria,statistical analysis,and outcomes were extracted.Results:Studies were conducted on male and female players aged 10-32 years old.The quality of the studies was moderate to high,and except for unclear bias for blinding outcome assessment,the risk of bias for all domains was low.Long-term application of the 11+improved most biomechanical measures and physiological responses except for lower extremity stability,ankle evertors time latency,ankle dorsiflexion,and proprioception.Conversely,the 11+showed acute negative effects on physical performance compared to dynamic warm-ups and non-significant effects on technical abilities.Conclusion:Mid-to-long-term implementation of the 11+improved the maj ority of biomechanical and a couple of physical measure s but showed no effects on technical skills.Precaution must be observed for using the 11+before competitions,as it could acutely decrease physical/technical performance.Given the contradictory nature of the literature,further studies should evaluate the short-to-mid-term effects of the 11+.Further studies are required to address ankle responses to the 11+intervention.

关键词： Football Futsal Injury prevention Systematic review

Thermal response of steel framing members in open car park fires

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Frontiers of Structural and Civil Engineering 2022年第9期16卷 1071-1088页

作者： Xia YAN Marion CHARLIER thomas GERNAY Department of Civil and Systems Engineering Johns Hopkins UniversityBaltimoreMD 21218USA ArcelorMittal Steligence Esch-sur-Alzette 4221Luxembourg

For open car park structures,adopting a performance-based structural fire design is often justified and allowed because the fire does not reach flashover.However,this design approach requires an accurate assessment of temperatures in structural members exposed to car fires.This paper describes a numerical study on the thermal exposure on steel framing members in open car park fires.Steel temperatures are computed by the coupling of computational fluid dynamics and finite element modeling,and by analytical models from the Eurocodes.In addition,the influence of galvanization on the steel temperature evolution is assessed.Results show that temperatures in unprotected beams and columns are influenced by the section geometry,car fire scenario,modeling approach,and use of galvanization.Galvanization slightly delays and reduces peak temperature.Regarding the different models,CFD-FEM(CFD:computational fluid dynamics,FEM:finite-element method)coupled models predict lower temperatures than the Hasemi model,because the latter conservatively assumes that the fire flame continuously touches the ceiling.Further,the Hasemi model cannot account for the effect of reduced emissivity from galvanization on the absorbed heat flux.Detailed temperature distributions obtained in the steel members can be used to complete efficient structural fire designs based on the member sections,structure layout,and use of galvanization.

关键词： open car park localized fire steel frame numerical modeling computational fluid dynamics

Heightened condition dependent expression of structural coloration in the faces,but not wings,of male and female flies

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Current Zoology 2022年第5期68卷 600-607页

作者： thomas E White Amy Locke Tanya Latty School of Life and Environmental Sciences The University of SydneySydney 2106Australia

Structurally colored sexual signals are a conspicuous and widespread class of ornament used in mate choice,though the extent to which they encode information on the quality of their bearers is not fully resolved.Theory predicts that signaling traits under strong sexual selection as honest indicators should evolve to be more developmentally integrated and exaggerated than nonsexual traits,thereby leading to heightened condition dependence.Here,we test this prediction through examination of the sexually dimorphic faces and wings of the cursorial fly Lispe cana.Males and females possess structural UV-white and golden faces,respectively,and males present their faces and wings to females during close-range,ground-based courtship displays,thereby creating the opportunity for mutual inspection.Across a field-collected sample of individuals,we found that the appearance of the faces of both sexes scaled positively with individual condition,though along separate axes.Males in better condition expressed brighter faces as modeled according to conspecific flies,whereas condition scaled with facial saturation in females.We found no such relationships for their wing interference pattern nor abdomens,with the latter included as a nonsexual control.Our results suggest that the structurally colored faces,but not the iridescent wings,of male and female L.cana are reliable guides to individual quality and support the broader potential for structural colors as honest signals.They also highlight the potential for mutual mate choice in this system,while arguing for 1 of several alternate signaling roles for wing interferences patterns among the myriad taxa which bear them.

关键词： honest signal iridescent mate choice sexual selection wing interference pattern

粗粒化强化有限-离散元多尺度耦合方法在颗粒-连续体表面动态作用问题上的应用

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Acta Mechanica Sinica 2023年第1期39卷 110-123页

作者：程宏旸 Stefan Luding thomas Weinhart University of Twente Chair of Soil MicroMechanics Department of Civil Engineering Faculty of Engineering Technology MESA+ Enschede The Netherlands (GRID:grid.6214.1) (ISNI:0000 0004 0399 8953) University of Twente Multi-Scale Mechanics Group Department of Thermal and Fluid Engineering Faculty of Engineering Technology MESA+ Enschede The Netherlands (GRID:grid.6214.1) (ISNI:0000 0004 0399 8953)

颗粒材料和可变形结构之间的相互作用与采矿、施工、粉末加工等许多工业过程相关.离散(DEM)和有限元法(FEM)之间的表面耦合通常用来模拟颗粒材料与连续体介质间的相互作用.本文使用最新提出“广义表面耦合”方法,通过粗粒化(CG)强化连... 详细信息

颗粒材料和可变形结构之间的相互作用与采矿、施工、粉末加工等许多工业过程相关.离散(DEM)和有限元法(FEM)之间的表面耦合通常用来模拟颗粒材料与连续体介质间的相互作用.本文使用最新提出“广义表面耦合”方法,通过粗粒化(CG)强化连续物理场从离散颗粒尺度数据中的提取,在离散-连续体接触面实现微观-宏观过渡.本文着重研究了颗粒-连续耦合系统中动量和能量的时间演化及其在CG宽度(即平滑内核有效范围)上的依赖性.通过三个数值算例,包括(1)密实颗粒流撞击柔性障碍物,(2)粘弹性立方体坠落并静止于颗粒床,(3)悬臂梁表面受重力作用滑动继而使梁弯曲的颗粒流,证明了CG强化的FEM-DEM表面耦合可以使数值结果更加准确,并减少耦合系统中的多余能量.通过比较三个计算实例,本文发现随着颗粒-连续体相互作用从静态到动态过度,CG强化面耦合方法的优势更加明显.随着CG宽度增加,耦合系统中过剩能量的衰减越强,高频振荡的振幅也越小,从而促进耦合系统中的应力松弛过程.但是最佳CG宽度的选择仍然取决于具体的耦合问题.

关键词：颗粒材料粗粒化多尺度耦合高频振荡可变形结构耦合系统连续体颗粒流

Complexities and pitfalls in analyzing and interpreting mitochondrial DNA content in human cancer

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Journal of Genetics and Genomics 2020年第7期47卷 349-359页

作者： Hieu Nguyen thomas LaFramboise Vinmec Research Institute of Stem Cell and Gene Technology(VRSIG) 458 M inh KhaiVinh TuyHai Ba TrungHanoiViet Nam Department of Genetics and Genome Sciences Case Western Reserve University School of Medicine10900 Euclid AvenueClevelandOH44106USA

Mutations in the human mitochondrial genome have been observed in all types of human cancer,indicating that mutations might contribute to tumorigenesis,metastasis,recurrence,or drug response.This possibility is appealing because of the known shift from oxidative metabolism to glycolysis,known as the Warburg effect,that occurs in malignancy.Mitochondrial DNA(mtDNA)mutations could either bematernally inherited and predispose to cancer(germ line mutations)or occur sporadically in the mtDNA of specific tissues(rissue-or tumor-specific somatic mutations)and contribute to the tumor initiation and progression process.High-throughput sequencing technologies now enable comprehensive detection of mtDNA variation in tissues and bodily fluids,with the potential to be used as an early detectiontool that may impact the treatment of cancer.Here,we discuss insights into the roles of mtDNA mutations in carcinogenesis,highlighting the complexities involved in the analysis and interpretation of mitochondrial genomic content.technical challenges in studying their contribution to pathogenesis,and the value of mtDNA mutations in developing early detection,diagnosis,prognosis,and therapeuticstrategics for cancer.

关键词： Mitochondrial DNA Cancer Genetic variation

A plant-based diet and stroke

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Journal of Geriatric Cardiology 2017年第5期14卷 321-326页

作者： thomas Campbell School of Medicine and Dentistry University of Rochester 601 Elmwood Ave Rochester NY 14642 USA.

Stroke is a leading cause of death and disability in theUnited States and globally. Each year, approxirnately 795,000Americans experience a stroke.Total annual costs of stroke,both direct and indirect, amount to $33 billion. Ischemicstroke is predicted to cost more than $2.2 trillion between2005 and 2050. In the United States, 87% of all strokesare ischemic, 10% are due to intracerebral hemorrhage, and3% are due to subarachnoid hemorrhage.

关键词： Anticoagulation Plant-based diet Prevention Stroke Vegan Vegetarian