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Journal of Central south University 2015年第2期22卷 638-645页

作者：范祥 kulatilake p h s w 陈新曹平 school of Resources and safety Engineering Central South University Rock Mass Modeling and Computational Rock Mechanics Laboratories University of Arizona school of Mechanics and Civil Engineering China University of Mining and Technology (Beijing)

The ratio of crack initiation stress to the uniaxial compressive strength(sCI,B/sUC,B) and the ratio of axial strain at the crack initiation stress to the axial strain at the uniaxial compressive strength(B,UCB,CI,A,A/ssss) were studied by performing numerical stress analysis on blocks having multi flaws at close spacing's under uniaxial loading using pFC3 D. The following findings are obtained: sCI,B/sUC,B has an average value of about 0.5 with a variability of ± 0.1. This range agrees quite well with the values obtained by former research. For joint inclination angle, β=90°,B,UCB,CI,A,A/ssss is found to be around 0.48 irrespective of the value of joint continuity factor, k. No particular relation is found betweenB,UCB,CI,A,A/ssss and β; however, the average B,UCB,CI,A,A/ssss seems to slightly decrease with increasing k. The variability ofB,UCB,CI,A,A/ssss is found to increase with *** on the cases studied in this work,B,UCB,CI,A,A/ssss ranges between 0.3 and 0.5. This range is quite close to the range of 0.4to 0.6 obtained for sCI,B/sUC,B. The highest variability of ± 0.12 forB,UCB,CI,A,A/ssss is obtained for k=0.8. For the remaining k values the variability ofB,UCB,CI,A,A/ssss can be expressed within ± 0.05. This finding is very similar to the finding obtained for the variability of sCI,B/sUC,B.

关键词： jointed rock multi flaws uniaxial loading pFC3D model crack initiation stress(sCI B) axial strain at crack initiation

Investigation of stability of a tunnel in a deep coal mine in China

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International Journal of Mining science and Technology 2013年第4期23卷 567-577页

作者： kulatilake p.h.s.w. wu Qiong Yu Zhengxing Jiang Fuxing Geological Engineering program Department of Materials Science & Engineering University of Arizona Faculty of Engineering China University of Geosciences China Academy of safety science and Technology school of Civil and Environmental Engineering University of Science and Technology Beijing

stability level of tunnels that exist in an underground mine has a great influence on the safety,production and economic performance of *** of stability for soft-rock tunnels is an important task for deep coal mines located in high in situ stress *** the available information on stratigraphy,geological structures,in situ stress measurements and geo-mechanical properties of intact rock and discontinuity interfaces,a three-dimensional numerical model was built by using 3DEC software to simulate the stress conditions around a tunnel located under high in situ stress conditions in a coal rock mass in *** were conducted for several tunnel shapes and rock support *** obtained for the distribution of failure zones,and stress and displacement felds around the tunnel were compared to select the best tunnel shape and support pattern to achieve the optimum stability conditions.

关键词： Coal mine Tunnel stability high in situ stress Numerical modeling 3DEC

基于二维经验分布的不连续面产状Monte Carlo模拟

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岩石力学与工程学报 2015年第S2期34卷 3922-3929页

作者：郑俊 kulatilake p h s w 邓建辉魏进兵浙江大学建筑工程学院浙江杭州310058 四川大学水力学与山区河流开发保护国家重点实验室四川成都610065 亚利桑那大学岩体模拟与计算力学实验室

描述不连续面产状的概率分布主要有:Fisher分布、Bingham分布和双正态分布。然而大部分实际岩体中不连续面产状统计特性不适用于这些理论分布。因此二维经验分布(根据实测产状而获得)是呈现实际岩体中不连续面产状比较有效的分布。本文... 详细信息

描述不连续面产状的概率分布主要有:Fisher分布、Bingham分布和双正态分布。然而大部分实际岩体中不连续面产状统计特性不适用于这些理论分布。因此二维经验分布(根据实测产状而获得)是呈现实际岩体中不连续面产状比较有效的分布。本文目的是介绍基于二维经验分布进行不连续面产状Monte Carlo模拟的方法,并利用Excel VBA开发了一款名为EMCsDO的程序。EMCsDO是为科研人员和工程师免费设计的,只需掌握一点计算机知识就能够快速掌握它的操作。最后给出2个算例,结果表明:(1)EMCsDO的模拟效果比较理想;(2)利用Monte Carlo模拟不连续面产状时,首先应检验样本产状对上述理论分布的拟合度,若能找到满足样本产状的理论分布,优先选用理论分布进行模拟,若找不到则用本文介绍的二维经验分布进行模拟。

关键词：岩石力学岩体节理网络结构面赤平投影拟合 x^(2)检验

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巷道齿状阻波墙厚度及设置方式优化研究

地下空间与工程学报 2022年第S1期18卷 57-64页

作者：黄敏 kulatilake p h s w 郭晓强邓骐宁黄明清紫金矿业集团股份有限公司福建上杭364200 江西理工大学资源与环境工程学院江西赣州341000 紫金(长沙)工程技术有限公司长沙410000 亚利桑那大学岩体模拟与计算力学实验室亚利桑那州图森85721 福州大学紫金地质与矿业学院福州350108

采空区综合治理是削弱或消除采空区安全隐患的具体措施。在研究国内外采空区治理现状的基础上,对封堵隔离方式进行了深入研究,从采空区顶板岩块冒落可能形成的两种冲击气浪形式出发,对岩块冒落诱导的风流速度进行了推导,分析了齿状阻波... 详细信息

采空区综合治理是削弱或消除采空区安全隐患的具体措施。在研究国内外采空区治理现状的基础上,对封堵隔离方式进行了深入研究,从采空区顶板岩块冒落可能形成的两种冲击气浪形式出发,对岩块冒落诱导的风流速度进行了推导,分析了齿状阻波墙的作用机理及受力状态,并就齿状阻波墙厚度、数量及设置方式进行理论与数值模拟计算分析。研究结果表明:钢筋混凝土齿状阻波墙理论计算厚度为1.5 m~2.5 m,其阻波效果随墙体面积减小而减小,但墙体面积越小则要求墙体厚、数量多;当阻波墙面积占巷道断面面积约1/2时,墙体阻波效果及墙体数量、厚度能达到较好效果,对于人员、设备通行也较为方便,可作为巷道及采空区封堵隔离的推广形式。研究结果可为构筑齿状阻波墙提供科学依据,为实现安全生产条件重构提供强有力的技术支撑。

关键词：采空区齿状阻波墙冲击波综合治理

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传统矿柱安全系数计算公式优化研究

矿冶工程 2020年第4期40卷 32-37页

作者：黄敏 kulatilake p h s w 罗嗣海方偏桃赵聪聪江西理工大学资源与环境工程学院江西赣州341000 长沙矿山研究院有限责任公司湖南长沙410012 金属矿山安全技术国家重点实验室湖南长沙410012 亚利桑那大学岩体模拟与计算力学实验室美国亚利桑那州图森85721

从矿柱强度、矿柱所受荷载等多方面对湖南省某铅锌矿采空区矿柱稳定性展开了深入研究,并采用基于面积承载理论及普氏理论对矿区1365根矿柱的安全系数进行了计算与分析,结果表明,2种理论计算出的矿柱安全系数相差较大,且基于面积承载理... 详细信息

从矿柱强度、矿柱所受荷载等多方面对湖南省某铅锌矿采空区矿柱稳定性展开了深入研究,并采用基于面积承载理论及普氏理论对矿区1365根矿柱的安全系数进行了计算与分析,结果表明,2种理论计算出的矿柱安全系数相差较大,且基于面积承载理论的矿柱安全系数计算公式过于保守。通过建立多种空区模型进行三维数值模拟计算与对比分析,并采用Matlab软件拟合出矿柱应力与矿柱间距、矿柱埋深之间的函数关系,最终得到适用于该铅锌矿的矿柱安全系数计算公式。研究结果可为其他类似矿山的矿柱设计、技术服务提供参考。

关键词：采空区矿柱稳定性矿柱安全系数面积承载理论普氏理论

Exploring one material for dual applications:A red-emitting Mg2GeO4:Eu3+ nanophosphor for future generation energy efficient wLEDs and dosimetric applications

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Journal of Rare Earths 2024年第10期42卷 1835-1845页

作者： Akshay Arjun G.p.Darshan s.C.sharma h.Nagabhushana D.V.sunitha h.B.premkumar Department of physics Faculty of Mathematical and Physical SciencesM.S.Ramaiah University of Applied Sciences Jain University C.N.R.Rao Centre for Advanced Materials Tumkur University school of Applied sciences (physics) REVA University

The envisaged design and developme nt of individual mate rials to excavate a broader spectrum of desired properties and offer multiple applications are highly *** this in mind,a series of forsterite-structured Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors was synthesized via a solution combustion method using oxalyl dihydrazide as a *** X-ray diffraction patterns confirm the orthorhombic crystal system with a puma space *** results clearly show irregularly shaped cluster-like structures with aggregation of the *** diffuse reflectance spectra,the optical energy band gap of the Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors was estimated and obtained to be～4.12-4.32 *** photoluminescence emission spectra exhibit intense peaks at ～579,589,610,661,and 707 nm,which are due to characteristic5D0→7F0,5D0→7F1,5Do→7F2,5D0→7F3and5D0→7F4transitions of Eu3+ions,*** Commission International de L'Eclairage color coordinates are gradually tuned from pale red（0.5980,0.4012） to a pure red（0.6385,0.3611） *** glow peaks showcase excellent super-linear response at low doses of γ-irradiations,indicating that the prepared phosphor can be used in thermoluminescent personal dosimetry which is a biological tissue *** aforementioned results demonstrate that the prepared Mg2GeO4:Eu3+（1 mol%-9 mol%） nanophosphors are considered an excellent candidate for dual applications,i.e.,red component in future generation white-light-emitting diodes（wLEDs） and personal dosimetric applications.

关键词： Dosimetry Nanophosphors photoluminescence photometric properties Rare earths Thermoluminescence

Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

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Chinese physics B 2024年第2期33卷 108-114页

作者： U.s.Mahabaleshwar G.p.Vanitha L.M.pérez Emad h.Aly I.pop Department of studies in Mathematics Davangere UniversityShivagangothriDavangereIndia Departamento de F´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile Department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt Department of Mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

we report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in h_(2)O past a stretched/shrinked *** the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is *** resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity *** transformed differential equations are solved *** of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted *** skin friction and Nusselt number were also *** addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching ***,Al_(2)O_(3)/h_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/h_(2)O ***,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection

seasonal changes in hermit Thrush (Catharus guttatus) song syntax

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Avian Research 2024年第2期15卷 172-179页

作者： sean p.Roach Luke C.McLean Jeff w.MacLeod Leslie s.phillmore psychology Department University of New Brunswick Saint John100 Tucker Park RoadSaint JohnNBCanada Department of psychology and Neuroscience Dalhousie University1355 Oxford StHalifaxNSB3H 4J1Canada

In many songbird species,birdsong features phonological syntax,meaning that the units within their vocal se-quences are ordered in a non-random way that adheres to a *** such syntactical patterns have been richly described in many species,comparatively little is known about how those patterns contribute to song achieving its important *** each of song’s main functions,territorial defense and mate attraction,evidence of a role for syntax is *** species for which syntax has been thoroughly described is the hermit Thrush(Catharus guttatus),which presents song types from their repertoires in a semi-predictable order and,in doing so,rapidly cycle up and down the frequency *** objective of the present study was to explore the importance of song syntax in the hermit Thrush through a within-subject examination of how measures of syntax,such as the predictability of song type order within song sequences,shift over the breeding *** hypothesized that,if such syntactical characteristics are important to breeding behaviour,they would be most prominent at the start of the breeding season when activity associated with territory establishment and mate attraction is most *** revealed that,as predicted,the rigidness of song type ordering within se-quences was highest at the start of the season and declined *** song type sequences were most predictable at the vitally important early part of the breeding season fit our hypothesis that this aspect of song syntax is important to song’s functions related to territory establishment and/or mate *** work will clarify whether that role relates to one of song’s two main functions or serves song transmission in some broader way.

关键词： Birdsong hermit Thrush seasonal change stereotypy syntax

Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.w.huang K.Jiang C.N.wu h.peng p.C.hen R.Li h.B.Zhuo C.T.Zhou shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

Construction of 2D/2D Ti_(3)C_(2)T_(x)MXene/Cds heterojunction with photothermal effect for efficient photocatalytic hydrogen production

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Journal of Materials science & Technology 2024年第4期171卷 1-9页

作者： T.Y.huang Z.Yang s.Y.Yang Z.h.Dai Y.J.Liu J.h.Liao G.Y.Zhong Z.J.Xie Y.p.Fang s.s.Zhang Key Laboratory for Biobased Materials and Energy of Ministry of Education Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China school of physics and Optoelectronics South China University of TechnologyGuangzhou 510640China school of Chemical Engineering and Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semiconductors to visible and infrared light is a key constraint on the utilization of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semiconductor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/Cds heterojunction catalyst is obtained by in-situ epitaxial growth of two-dimensional(2D)Cds nanosheets on 2D MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstanding full-spectrum driven photocat-alytic hydrogen evolution capability upon the heterogeneous *** unique 2D/2D structure effectively mitigated the recombination of photogenerated carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃under visible light irradiation at an intensity of 0.1 w/cm^(2),which is 1.84 times higher than that of *** irradiation of visible and near infrared light,the composite catalyst with photothermal ef-fect demonstrates a remarkable hydrogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of Cds *** study introduces a novel approach for constructing full-spectrum absorption catalysts and expands the application of the photothermal effect in photocatalytic hydrogen evolution research.

关键词： Two-dimensional structure heterostructure photothermal effect photocatalyst hydrogen evolution