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Spalling characteristics of high-temperature treated granitic rock at different strain rates

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1280-1288页

作者： L.f.fan Q.H.Yang X.L.Du The Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing100124China

The dynamic spalling characteristics of rock are important for stability analysis in rock *** paper presented an experimental investigation on the dynamic spalling characteristics of granite with different temperatures and strain rates.A series of dynamic spalling tests with different impact velocities were conducted on thermally treated granite at different *** dynamic spalling strengths of granite with different temperatures and strain rates were determined.A model was proposed to correlate the dynamic spalling strength of granite,high temperature and strain *** results show that the spalling strength of granite decreases with increasing ***,the spalling strength of granite with a higher strain rate is larger than that with a lower strain *** proposed model can describe the relationship among dynamic spalling strength of granite,high temperature and strain rate.

关键词： Dynamic spalling characteristics High temperature Strain rate Dynamic loading Granite

Commentary on“Incidence of urinary incontinence following endoscopic laser enucleation of the prostate by en-bloc and non-en-bloc techniques:a multicenter,real-world experience of 5068 patients”

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Asian Journal of Andrology 2024年第3期26卷 333-334页

作者： James f Jiang Narmina K Onder Akhil K Das Department of Urology University of California Irvine Orange CA 92868 USA

Laser enucleation of the prostate is a proven and effectivesize-independent method for the surgical management of symptomaticbenign prostatic hyperplasia(BPH)and is considered as the“goldstandard”by many *** major hurdles that stand in theway of this becoming a universally used procedure for BPH are thesteep learning curve associated with mastering the procedure andpossibility of perioperative transient *** advances inteaching methodologies have helped tackle the difficulty in learning itand increased the number of urologists utilizing the *** forthe second hurdle,transient incontinence rates postlaser enucleationof the prostate have improved with the advent of newer techniques *** et al.1 assesses the incidence of stress,urge,andmixed urinary incontinence following laser enucleation of the prostateby comparing en-bloc and non-en-bloc techniques in a multicenterseries of 5068 men with BPH.

关键词： urinary incontinence transient

具有BCC或fCC晶体结构的固溶体高熵合金设计

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材料工程 2024年第1期52卷 16-26页

作者： HORBAN V.f. 乌克兰国家科学院弗兰采维奇材料问题研究所乌克兰基辅03680

高熵合金最初报道于21世纪初期,该类合金具有较高的混合熵值,使其具有优异的热稳定性;较大的晶格畸变,产生了强烈固溶强化效果;较大的负焓值导致在晶粒内部形成团簇结构,有效阻碍了位错运动,进一步提高了合金强度。高熵合金独有的这些特... 详细信息

高熵合金最初报道于21世纪初期,该类合金具有较高的混合熵值,使其具有优异的热稳定性;较大的晶格畸变,产生了强烈固溶强化效果;较大的负焓值导致在晶粒内部形成团簇结构,有效阻碍了位错运动,进一步提高了合金强度。高熵合金独有的这些特性,使其在低温和高温条件下均有望表现出优异的物理性能和力学性能,引起了广泛的关注,研究报道呈爆发性增长。本文根据已有的BCC和fCC结构高熵合金物理-力学性能数据,分析了电子浓度、晶格常数、原子错配度、混合焓、硬度、弹性模量和归一化硬度等参数之间的关系,提出了BCC和fCC晶体结构的高熵合金弹性模量和硬度的经验计算公式,在此基础之上,综合考虑合金密度、塑性和服役工况等条件,提出了BCC和fCC结构的高熵合金成分设计方法。最后指出高熵合金的持久性能、大尺寸铸锭的成分和性能均匀性以及大尺寸合金锭的制备是高熵合金工程应用需解决的关键问题。

关键词：高熵合金电子浓度晶格常数晶格畸变混合焓硬度弹性模量归一化硬度

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Stochastic seismic inversion and Bayesian facies classification applied to porosity modeling and igneous rock identification

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Petroleum Science 2024年第2期21卷 918-935页

作者： fábio Júnior Damasceno fernandes Leonardo Teixeira Antonio fernando Menezes freire Wagner Moreira Lupinacci Exploratory Interpretation and Reservoir Characterization Group(GIECAR) Department of Geology and GeophysicsFederal Fluminense UniversityNiter oiRJ24210-346Brazil Petrobras Rio de JaneiroRJ20231-030Brazil National Institute of Science and Technology of Petroleum Geophysics(INCT-GP/CNPQ) Niter oiRJ24210-346Brazil

We apply stochastic seismic inversion and Bayesian facies classification for porosity modeling and igneous rock identification in the presalt interval of the Santos Basin. This integration of seismic and well-derived information enhances reservoir characterization. Stochastic inversion and Bayesian classification are powerful tools because they permit addressing the uncertainties in the model. We used the ES-MDA algorithm to achieve the realizations equivalent to the percentiles P10, P50, and P90 of acoustic impedance, a novel method for acoustic inversion in presalt. The facies were divided into five: reservoir 1,reservoir 2, tight carbonates, clayey rocks, and igneous rocks. To deal with the overlaps in acoustic impedance values of facies, we included geological information using a priori probability, indicating that structural highs are reservoir-dominated. To illustrate our approach, we conducted porosity modeling using facies-related rock-physics models for rock-physics inversion in an area with a well drilled in a coquina bank and evaluated the thickness and extension of an igneous intrusion near the carbonate-salt interface. The modeled porosity and the classified seismic facies are in good agreement with the ones observed in the wells. Notably, the coquinas bank presents an improvement in the porosity towards the top. The a priori probability model was crucial for limiting the clayey rocks to the structural lows. In Well B, the hit rate of the igneous rock in the three scenarios is higher than 60%, showing an excellent thickness-prediction capability.

关键词： Stochastic inversion Bayesian classification Porosity modeling Carbonate reservoirs Igneous rocks

Proposed numerical and machine learning models for fiber-reinforced polymer concrete-steel hollow and solid elliptical columns

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frontiers of Structural and Civil Engineering 2024年第8期18卷 1169-1194页

作者： Tang QIONG Ishan JHA Alireza BAHRAMI Haytham f.ISLEEM Rakesh KUMAR Pijush SAMUI School of Applied Technologies Qujing Normal UniversityQujing 655011China Department of Civil Engineering Indian Institute of Technology-BHUVaranasi 221005India Department of Building Engineering Energy Systems and Sustainability ScienceFaculty of Engineering and Sustainable DevelopmentUniversity of GävleGävle 80176Sweden Department of Civil Engineering National Institute of Technology-PatnaPatna 800005India

This study employs a hybrid approach,integrating finite element method(fEM)simulations with machine learning(ML)techniques to investigate the structural performance of double-skin tubular columns(DSTCs)reinforced with glass fiber-reinforced polymer(GfRP).The investigation involves a comprehensive examination of critical parameters,including aspect ratio,concrete strength,number of GfRP confinement layers,and dimensions of steel tubes used in DSTCs,through comparative analyses and parametric *** ensure the credibility of the findings,the results are rigorously validated against experimental data,establishing the precision and trustworthiness of the *** present research work examines the use of the columns with elliptical cross-sections and contributes valuable insights into the application of fEM and ML in the design and evaluation of structural systems within the field of structural engineering.

关键词： elliptical column fiber-reinforced polymer machine learning finite element method ABAQUS

SnRK1a1, a new player in the sucrose-Opaque2 network during endosperm filling

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Molecular Plant 2024年第8期17卷 1172-1174页

作者： Kelly Mayrink Balmant Marcio f.R.Resende Jr. Horticultural Sciences Department University of FloridaGainesvilleFLUSA

Maize(Zea mays)endosperm is an important food source for humans and *** addition,it is considered an excellent model for research on seed development because of its relatively large size for both embryo and endosperm compared to those of other crop species,such as rice(Oryza sativa)and wheat(Triticum aestivum).After double fertilization,early maize endosperm development includes three stages:(i)a multinucleate coenocyte stage;(i)a cellularization stage,in which the cellular endosperm is formed;and(ii)a stage of differentiation into distinct *** early differentiation,four major cell types with specific functions differentiate within the endosperm:starchy endosperm,aleurone layer,basal endosperm transfer layer(BETL),and embryo surrounding *** subaleurone,conducting zone,basal intermediate zone,and endosperm adjacent to scutellum arise in late differentiation(Sabelli and Larkins 2009).After the main cell types are established,maize endosperm undergoes intensive cell proliferation,which marks the transition to the endosperm-filling *** the endosperm-flling stage,the maternal sucrose products are transported to seeds through the BETL region,where they will act as the main carbon substrate for storage products such as starch and proteins(Chen et al.,2023).In fact,the endosperm of maize seeds accounts for approximately 90%of the total grain weight,serving as an important nutrient reservoir(flint-Garcia et al.,2009).

关键词： endosperm reservoir flint

Effects of dust controls on respirable coal mine dust composition and particle sizes:case studies on auxiliary scrubbers and canopy air curtain

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International Journal of Coal Science & Technology 2024年第3期11卷 86-101页

作者： f.Animah C.Keles W.R.Reed E.Sarver Department of Mining and Minerals Engineering Virginia Polytechnic Institute&State UniversityBlacksburgVAUSA National Institute of Occupational Safety and Health(NIOSH) PittsburghPAUSA

Control of dust in underground coal mines is critical for mitigating both safety and health *** decades,the National Institute of Occupational Safety and Health(NIOSH)has led research to evaluate the effectiveness of various dust control technologies in coal *** studies have included the evaluation of auxiliary scrubbers to reduce respirable dust downstream of active mining and the use of canopy air curtains(CACs)to reduce respirable dust in key operator *** detailed dust characterization was not a focus of such studies,this is a growing area of *** preserved filter samples from three previous NIOSH studies,the current work aims to explore the effect of two different scrubbers(one wet and one dry)and a roof bolter CAC on respirable dust composition and particle size *** this,the preserved filter samples were analyzed by thermogravimetric analysis and/or scanning electron microscopy with energy dispersive *** indicate that dust composition was not appreciably affected by either scrubber or the ***,the wet scrubber and CAC appeared to decrease the overall particle size *** an effect of the dry scrubber was not consistently observed,but this is probably related to the particular sampling location downstream of the scrubber which allowed for significant mixing of the scrubber exhaust and other return *** from the insights gained with respect to the three specific dust control case studies revisited here,this work demonstrates the value of preserved dust samples for follow-up investigation more broadly.

关键词： Respirable dust Dust control SEM–EDX Scrubber Canopy air curtain Silica

Converting TREx-RGB green-channel data to 557.7 nm auroral intensity:Methodology and initial results

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Earth and Planetary Physics 2024年第1期8卷 258-274页

作者： Jun Liang D.M.Gillies E.Spanswick E.f.Donovan University of Calgary CalgaryT2N 1N4Canada

The recently deployed Transition Region Explorer(TREx)-RGB(red-green-blue)all-sky imager(ASI)is designed to capture“true color”images of the aurora and *** the 557.7 nm green line is usually the brightest emission line in visible auroras,the green channel of a TREx-RGB camera is usually dominated by the 557.7 nm *** this rationale,the TREx mission does not include a specific 557.7 nm imager and is designed to use the RGB green-channel data as a proxy for the 557.7 nm *** this study,we present an initial effort to establish the conversion ratio or formula linking the RGB green-channel data to the absolute intensity of 557.7 nm auroras,which is crucial for quantitative uses of the RGB *** illustrate two approaches:(1)through a comparison with the collocated measurement of green-line auroras from the TREx spectrograph,and(2)through a comparison with the modeled green-line intensity according to realistic electron precipitation flux measurements from low-Earth-orbit satellites,with the aid of an auroral transport *** demonstrate the procedures and provide initial results for the TREx-RGB ASIs at the Rabbit Lake and Lucky Lake *** RGB response is found to be *** conversion ratios or formulas between RGB green-channel data and the green-line auroral intensity are given and can be applied immediately by TREx-RGB data *** methodology established in this study will also be applicable to the upcoming SMILE ASI mission,which will adopt a similar RGB camera system in its deployment.

关键词： TREx RGB green-line aurora auroral transport model

Assembly structures of coastal woody species of eastern South America:Patterns and drivers

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Plant Diversity 2024年第5期46卷 611-620页

作者： Eduardo Vinícius da Silva Oliveira Myrna friederichs Landim Sidney f.Gouveia Graduate Program in Ecology and Conservation Federal University of SergipeSão CristovãoSergipeBrazil National Institute of Science and Technology Ecology Evolution and Conservation of Biodiversity(INCT-EECBio)GoiâniaGoiasBrazil Department of Biology Federal University of SergipeSão CristóvãoSergipeBrazil Department of Ecology Federal University of SergipeSão CristóvãoSergipeBrazil

Tropical regions have provided new insights into how ecological communities are *** dry coastal communities,water stress has been hypothesized to determine plant assembly structure by favoring preadapted lineages from neighboring ecosystems,consistent with functional ***,it is unclear whether this hypothesis is sufficient to explain how coastal communities in tropical ecosystems are ***,we test whether water stress or other factors drive community assembly in woody plant communities across the coastal zone of Brazil,a tropical *** characterized functional and phylogenetic structures of these communities and determined the underlying environmental factors(e.g.,water stress,historical climate stability,edaphic constraints,and habitat heterogeneity)that drive their community *** of coastal woody species show geographically varied patterns,including stochastic arrangements,clustering,and overdispersion of species relative to their traits and phylogenetic *** complexity,water vapor pressure,and soil nutrient availability best explained the gradient in the functional *** deficit,water vapor pressure,and soil organic carbon were the best predictors of variation in phylogenetic *** results support the water-stress conservatism hypothesis on functional and phylogenetic structure,as well as the effect of habitat heterogeneity on functional structure and edaphic constraints on functional and phylogenetic *** effects are associated with increased phenotypic and phylogenetic divergence of woody plant assemblages,which is likely mediated by abiotic filtering and niche opportunities,suggesting a complex pattern of ecological assembly.

关键词： Brazil Completeness Clustering Restinga vegetation Water constraints