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Analysis and design of axially loaded piles in rock

Journal of Rock mechanics and Geotechnical Engineering 2019年第3期11卷 535-548页

作者： c.m.haberfield A.L.E.Lochaden Golder Associates Pty.Ltd. MelbourneAustralia

Despite significant advancements in in situ test techniques,construction practices,understanding of rock joint and rock mass behaviours,and numerical analysis methods,the design of bored concrete cast-insitu piles in rock is still largely based on the assessment of bearing capacity.However,for many of the rock conditions encountered,the bearing capacity of piles is a nebulous concept and a figment of the designer’s imagination.Even if it can be reasonably quantified,it has little,if any,significance to the performance of a pile in rock.The load carrying capacity of even low strength rock(in most situations)is far in excess of the strength of the structure(for example,a building column)transmitting the load.Unsatisfactory performance of a pile in rock is usually a displacement issue and is a function of rock mass stiffness rather than rock mass strength.In addition,poor pile performance is much more likely to result from poor construction practices than excessive displacement of the rock mass.Exceptions occur for footings that are undermined,or where unfavourable structure in the rock allows movement towards a free surface to occur.Standards,codes of practices,reference books and other sources of design information should focus foundation design in rock on displacement rather than strength performance.Ground investigations should measure rock mass stiffness and defect properties,as well as intact rock strength.This paper summarises the fundamental concepts relating to performance of piles in rock and provides a basis for displacement focused design of piles in rock.It also presents comments relating to how piles are modelled in widely used commercial finite element software for soil-structure interaction analysis,within the context of the back-analysis of a pile load test,and proposes recommendations for pile analysis and design.

关键词： Pile design Pile analysis Pile load test Finite element analysis

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节理粗糙度研究的新进展

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地质科学译丛 1996年第2期13卷 70-78页

作者： J.P.Seidel c.m.haberfield 杨翠珠 Department of civil Engineering Monash UniversityClaytonAustralia

当前采用的节理模型,如果不凭借经验,是不可能准确预测节理的剪切行为的,这已成为争论的热点。这是因为这些模型不能定量地评价节理粗糙度或尺度的重要性。介绍一种新的方法,它用分形几何来调查节理的粗糙度。这种方法已超出了简单地描... 详细信息

当前采用的节理模型,如果不凭借经验,是不可能准确预测节理的剪切行为的,这已成为争论的热点。这是因为这些模型不能定量地评价节理粗糙度或尺度的重要性。介绍一种新的方法,它用分形几何来调查节理的粗糙度。这种方法已超出了简单地描述粗糙度的“症状”,而是去寻找“原因”。在该法的应用中,引入了分形几何、分维数和自相似的概念,并系统地阐述岩体节理粗糙度的统计依据和实用模型的框架。推导了分维数和起伏角与粗糙高度的标准差这两个更有用统计参数之间的重要关系。这些关系不仅为定量评价节理粗糙度提供了有用的方法,而且为解释巴顿(Barton)的经验模型(JRc-JcS)提供了基础。另外,分形模型可以为节理剪切行为的正应力作用效应和节理尺度效应提供理论模型。

关键词：节理粗糙度系数分维数自相似岩石

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multichannel coupling induced topological insulating phases with full multimerization

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Photonics Research 2024年第3期12卷 491-498页

作者： JUN LI YAPING YANG c-m.HU mOE Key Laboratory of Advanced micro-Structured materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Physics and Astronomy University of ManitobaWinnipegManitoba R3T 2N2Canada

We propose and experimentally realize a class of quasi-one-dimensional topological lattices whose unit cells are constructed by coupled multiple identical resonators,with uniform hopping and inversion symmetry.In the presence of coupling-path-induced effective zero hopping within the unit cells,the systems are characterized by complete multimerization with degenerate-1 energy edge states for open boundary condition.

关键词： symmetry topological coupling

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The influence of resistance exercise training prescription variables on skeletal muscle mass,strength,and physical function in healthy adults:An umbrella review

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Journal of Sport and Health Science 2024年第1期13卷 47-60页

作者： Jonathan c.mcleod Brad S.currier caroline V.Lowisz Stuart m.Phillips Department of Kinesiology Faculty of ScienceMcMaster UniversityHamilton L8S4L8Canada

Purpose:The aim of this umbrella review was to determine the impact of resistance training(RT)and individual RT prescription variables on muscle mass,strength,and physical function in healthy adults.methods:Following Preferred Reporting Items for Systematic Reviews and meta-Analyses(PRISmA)guidelines,we systematically searched and screened eligible systematic reviews reporting the effects of differing RT prescription variables on muscle mass(or its proxies),strength,and/or physical function in healthy adults aged>18 years.Results:We identified 44 systematic reviews that met our inclusion criteria.The methodological quality of these reviews was assessed using A measurement Tool to Assess Systematic Reviews;standardized effectiveness statements were generated.We found that RT was consistently a potent stimulus for increasing skeletal muscle mass(4/4 reviews provide some or sufficient evidence),strength(4/6 reviews provided some or sufficient evidence),and physical function(1/1 review provided some evidence).RT load(6/8 reviews provided some or sufficient evidence),weekly frequency(2/4 reviews provided some or sufficient evidence),volume(3/7 reviews provided some or sufficient evidence),and exercise order(1/1 review provided some evidence)impacted RT-induced increases in muscular strength.We discovered that 2/3 reviews provided some or sufficient evidence that RT volume and contraction velocity influenced skeletal muscle mass,while 4/7 reviews provided insufficient evidence in favor of RT load impacting skeletal muscle mass.There was insufficient evidence to conclude that time of day,periodization,inter-set rest,set configuration,set end point,contraction velocity/time under tension,or exercise order(only pertaining to hypertrophy)influenced skeletal muscle adaptations.A paucity of data limited insights into the impact of RT prescription variables on physical function.conclusion:Overall,RT increased muscle mass,strength,and physical function compared to no exercise.RT intensity(load)and weekly frequency impacted RT-

关键词： Hypertrophy Resistance training Resistance training prescription variables Strength Umbrella review

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Semi-analytical investigation of heat transfer in a porous convective radiative moving longitudinal fin exposed to magnetic field in the presence of a shape-dependent trihybrid nanofluid

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Applied mathematics and mechanics(English Edition) 2024年第1期45卷 197-216页

作者： c.G.PAVITHRA B.J.GIREESHA m.L.KEERTHI Department of PG Studies and Research in mathematics Kuvempu UniversityShankaraghatta 577451India Department of mathematics and Statistics M.S.Ramaiah University of Applied SciencesBengaluru 560058India

The thermal examination of a non-integer-ordered mobile fin with a magnetism in the presence of a trihybrid nanofluid(Fe_3O_4-Au-Zn-blood) is carried out. Three types of nanoparticles, each having a different shape, are considered. These shapes include spherical(Fe_3O_4), cylindrical(Au), and platelet(Zn) configurations. The combination approach is utilized to evaluate the physical and thermal characteristics of the trihybrid and hybrid nanofluids, excluding the thermal conductivity and dynamic viscosity. These two properties are inferred by means of the interpolation method based on the volume fraction of nanoparticles. The governing equation is transformed into a dimensionless form, and the Adomian decomposition Sumudu transform method(ADSTm) is adopted to solve the conundrum of a moving fin immersed in a trihybrid nanofluid. The obtained results agree well with those numerical simulation results, indicating that this research is reliable. The influence of diverse factors on the thermal overview for varying noninteger values of γ is analyzed and presented in graphical representations. Furthermore, the fluctuations in the heat transfer concerning the pertinent parameters are studied. The results show that the heat flux in the presence of the combination of spherical, cylindrical, and platelet nanoparticles is higher than that in the presence of the combination of only spherical and cylindrical nanoparticles. The temperature at the fin tip increases by 0.705 759% when the value of the Peclet number increases by 400%, while decreases by 11.825 13% when the value of the Hartman number increases by 400%.

关键词： convection radiation moving longitudinal fin Adomian decomposition Sumudu transform method(ADSTm) trihybrid nanofluid magnetic field

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cannabinoids and endocannabinoids as therapeutics for nervous system disorders:preclinical models and clinical studies

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Neural Regeneration Research 2024年第4期19卷 788-799页

作者： R.Scott Duncan Sean m.Riordan matthew c.Gernon Peter Koulen Department of Ophthalmology School of MedicineUniversity of Missouri Department of Biomedical Sciences School of MedicineUniversity of Missouri

cannabinoids are lipophilic substances derived from cannabis sativa that can exert a variety of effects in the human body.They have been studied in cellular and animal models as well as in human clinical trials for their therapeutic benefits in several human diseases.Some of these include central nervous system(cNS)diseases and dysfunctions such as forms of epilepsy,multiple sclerosis,Parkinson’s disease,pain and neuropsychiatric disorders.In addition,the endogenously produced cannabinoid lipids,endocannabinoids,are critical for normal cNS function,and if controlled or modified,may represent an additional therapeutic avenue for cNS diseases.This review discusses in vitro cellular,ex vivo tissue and in vivo animal model studies on cannabinoids and their utility as therapeutics in multiple cNS pathologies.In addition,the review provides an overview on the use of cannabinoids in human clinical trials for a variety of cNS diseases.cannabinoids and endocannabinoids hold promise for use as disease modifiers and therapeutic agents for the prevention or treatment of neurodegenerative diseases and neurological disorders.

关键词： anandamide cannabidiol cannabinoid endocannabinoid epilepsy multiple sclerosis neurodegeneration neuroprotection tetrahydrocannabinol

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Foraging valor linked with aggression:selection against completely abandoning aggression in the high-elevation ant Tetramorium alpestre?

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Insect Science 2024年第3期31卷 953-970页

作者： marie-Luise contala Patrick Krapf Florian m.Steiner Birgit c.Schlick-Steiner molecular Ecology Group Department of EcologyUniversitat InnsbruckInnsbruckAustria rganismal&Evolutionary Biology Research Programme University of HelsinkiHelsinkiFinland

Aggression has multiple benefits and is often coupled with other behaviors("behavioral syndromes").The level of aggressiveness is influenced by an adaptive benefit-cost ratio suggesting that benefits should outweigh the costs of aggression.Here,we assess if several behaviors are coupled in two behaviorally different populations(aggressive,peaceful)of the high-elevation ant Tetramorium alpestre.For three weeks,we collected colony fragments and analyzed boldness,exploring,foraging,and risk-taking behaviors.We hypothesized that the aggressive population is bolder,more explorative and risk-prone,and forages more food than the peaceful population.To test whether(a)the combination of experiments and parameters used yields a good setup,(b)populations differ behaviorally,and(c)populations display behavioral syndromes,we assessed(a)the frequency of repeatable behaviors of each experiment,(b)the behavioral means among populations,and(c)the behavioral repeatability,respectively.We found that(a)boldness and exploring were most repeatable and represent a good experimental setup,(b)the aggressive population was bolder and more explorative and risk-prone than the peaceful population,(c)boldness and exploring behaviors were highly repeatable in both populations,thus corroborating our hypothesis.The results suggest that boldness,exploring,and risk-taking but not foraging are presumably coupled with aggression and indicate the presence of behavioral syndromes in this ant.Under specific ecological conditions,aggression may be coupled with other behaviors and important for finding food.Aggression is probably adaptive in T.alpestre,possibly indicating that selection favors aggression at least partially,which may counteract the complete loss of intraspecific aggression.

关键词： adaptive value behavioral syndromes boldness exploration repeatability trade-off

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Effect of radiative loss mechanisms on FIR thermometric parameters of Nd3+-doped lithium tellurite glasses

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Journal of Rare Earths 2024年第7期42卷 1250-1257页

作者： c.Y.morassuti A.P.L Silva L.A.O.Nunes S.m.Lima L.H.c.Andrade Optical and Photothermal Spectroscopy Group (GEOF) Center for Studies in Natural Resources (CERNA)State University of Mato Grosso do Sul(UEMS) Renato Archer Information Technology center Institute of Physics of Sao carlos University of S?o Paulo

Nd3+-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio（FIR） technique.Nevertheless,at high Nd3+concentrations,energy transfer（ET） processes such as optical reabsorption and cross-relaxation can affect the Nd3+emission,which has been little explored in the literature.Therefore,the present work investigated the use of Nd3+-doped tellurite glass(samples doped with Nd3+at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%) in fluorescence thermometers,in the temperature range from 299 to 371 K.The results indicate a strong dependence of the FIR parameters on the Nd3+concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd3+emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio4F5/2→4I9/2/4F3/2→4I9/2is observed for samples doped with higher amounts of Nd3+.The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd3+ions.

关键词： Fluorescence intensity ratio Judd-Ofelt Nd3+-doped tellurite glass Optical thermometry Rare earths

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Radiative decays D*(s)→ D(s)γ in covariant confined quark model

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chinese Physics c 2024年第2期48卷 45-56页

作者： c.T.Tran m.A.Ivanov P.Santorelli Q.c.Vo Department of Physics HCMC University of Technology and EducationVo Van Ngan 1700000 Ho Chi Minh CityVietnam Bogoliubov Laboratory of Theoretical Physics Joint Institute for Nuclear Research141980 DubnaRussia Dipartimento di Fisica"E.Pancini" Universitàdi Napoli Federico ⅡComplesso Universitario di Monte S.AngeloVia CintiaEdificio 680126 NapoliItaly Istituto Nazionale di Fisica Nucleare Sezione di Napoli80126 NapoliItaly University of Science 700000 Ho Chi Minh CityVietnam

Radiative decays D((s))*→D((s))γare revisited in light of new experimental data from the BaBar and BESⅢcollaborations.The radiative couplings gD*Dγencoding nonperturbative QcD effects are calculated in the framework of the covariant confined quark model developed by us.We compare our results with other theoretical studies and experimental data.The couplings(in GeV-1)|g(D*+D+γ)|=0.45(9)and|g(D*0D0γ)|=1.72(34)calculated in our model agree with the corresponding experimental data|g(D*+D+γ)|=0.47(7)and|g(D*0D0γ)|=1.77(16).The most interesting case is the decay Ds*→Dsγ,for which a recent prediction based on light-cone sum rules at next-to-leading order|gDs*Dsγ|=0.60(19)deviates from the first(and only to date)lattice QcD result|gDs*Dsγ|=0.11(2)at nearly3σ.Our calculation yields|gDs*Dsγ|=0.29(6),which falls somehow between the two mentioned results,although it is larger than those predicted in other studies using quark models or QcD sum rules.

关键词： covariant quark model radiative decay charmed meson

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Laser-induced graphene-coated wearable smart textile electrodes for biopotentials signal monitoring

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Frontiers of materials Science 2024年第1期18卷 95-111页

作者： c.m.Vidhya Yogita maithani Sakshi Kapoor J.P.Singh Department of Physics Indian Institute of Technology DelhiHauz KhasNew Delhi 110016India

This paper describes how to produce a wearable dry electrode at a reasonable cost and how to use it for the monitoring of biopotentials in electrocardiography.Smart textiles in wearable technologies have made a great advancement in the health care management and living standards of humans.Graphene was manufactured using the low-cost single-step process,laser ablation of polyimide,a commercial polymer.Graphene dispersions were made using solvent isopropyl alcohol which has low boiling point,nontoxicity,and environmental friendliness.After successive coating of the graphene dispersion on the cotton fabric to make it conductive,the sheet resistance of the resulting fabric dropped to 3% of its initial value.The laser-induced graphene(LIG)cotton dry electrodes thus manufactured are comparable to Ag/Agcl wet electrodes in terms of the skin-to-electrode impedance,measuring between 78.0 and 7.2 kΩ for the frequency between 40 Hz and 1 kHz.The LIG cotton electrode displayed a signal-to-noise ratio of 20.17 dB.Due to its comfort,simplicity,and good performance over a longer period of time,the textile electrode appears suited for medical applications.

关键词： biopotential electrocardiogram electromyogram flexible electrode textile porous graphene

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