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Deformation features and failure mechanism of steep rock slope under the mining activities and rainfall

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Journal of Mountain Science 2017年第1期14卷 31-45页

作者： LI Zhi-qiang XUE Yi-guo LI Shu-cai zhang le-wen WANG Dan LI Bin zhang wen NING Kai ZHU Jian-ye Research Center of Geotechnical and Structural Engineering Shandong University Resources Institute of GeomechanicsChinese Academy of Geological Sciences College of Construction Engineering Jilin University

Underground mining activities and rainfall have potential important influence on the initiation and reactivation of the slope deformations,especially on the steep rock slope. In this paper,using the discrete element method(UDEC),numerical simulation was carried out to investigate deformation features and the failure mechanism of the steep rock slope under mining activities and rainfall. A steep rock slope numerical model was created based on a case study at the Wulong area in Chongqing city,China. Mechanical parameters of the rock mass have been determined by situ measurements and laboratory measurements. A preliminary site monitoring system has been realized,aiming at getting structure movements and stresses of unstablerock masses at the most significant discontinuities. According to the numerical model calibrated based on the monitoring data,four types of operation conditions are designed to reveal the effect of mining excavation and extreme rainfall on the deformation of the steep rock slope.

关键词： Slope deformation Underground mining Discrete Element Method Site monitoring system

Large Active Area AlGaN Solar-Blind Schottky Avalanche Photodiodes with High Multiplication Gain

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Chinese Physics letters 2013年第3期30卷 176-178页

作者： LI Jian-Fei HUANG Ze-Qiang zhang wen-le JIANG Hao State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-sen UniversityGuangzhou 510275

We report the fabrication and performance of solar-blind AlGaN Schottky avalanche photodiodes grown on sapphire *** increased active donor density is found near the surface,leading to an enhanced electric field adjacent to the Schottky *** gain over 2000 has been achieved in the fabricated devices with a mesa diameter of 200μ*** measured dark I–V curves at different temperatures show strong temperature dependence,suggesting that the gain mechanism in our devices is primarily due to impact *** responsivity of 66.3 mA/W is obtained at 260 nm and at zero bias,corresponding to an external quantum efficiency of 31.6%.

关键词： Schottky AlGaN sapphire

断层作用下隧道掌子面突水力学机理研究及工程应用

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Journal of Central South University 2023年第3期30卷 934-946页

作者：张乐文吴静张翔宇 Institute of Marine Science and Technology Shandong UniversityQingdao 266237China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China

本文采用极限平衡法、条分法和弹性力学方法研究了断层作用下隧道掌子面突水力学机理,推导了防突层最小安全厚度的半解析表达式。将防突层安全厚度预测方法应用到齐岳山隧道实际工程案例中,通过对比实际开挖结果,验证了所提新方法的准... 详细信息

本文采用极限平衡法、条分法和弹性力学方法研究了断层作用下隧道掌子面突水力学机理,推导了防突层最小安全厚度的半解析表达式。将防突层安全厚度预测方法应用到齐岳山隧道实际工程案例中,通过对比实际开挖结果,验证了所提新方法的准确性和有效性。在以上案例研究的基础上,进一步分析和讨论岩溶水压力、断层倾角、破碎带宽度和破碎带抗剪强度指标对防突层最小安全厚度的影响,结果表明:1)防突层最小安全厚度随着岩溶水压力的增加而逐渐增加;2)随着断层倾角的增大,防突层最小安全厚度呈先增大后减小的趋势,且当断层倾角在45°~60°之间时,隧道掌子面易发生突水;3)随着破碎带宽度的增加,防突层最小安全厚度呈线性增大趋势;4)随着破碎带抗剪强度的增大,防突层最小安全厚度呈线性减小趋势;5)随着破碎带垂直压力的增大,防突层最小安全厚度增大。研究结果为隧道突水计算方法与理论研究提供了一种新的思路,对类似工程具有一定的借鉴意义与应用价值。

关键词：极限平衡法条分法弹性力学方法突水机理断层

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径向基函数神经网络在地应力场反演中的应用

岩土力学 2012年第3期33卷 799-804页

作者：张乐文张德永邱道宏山东大学岩土与结构工程研究中心济南250061 中国石油天然气工程建设公司岩土公司山东青岛266071

初始地应力场是地下洞室设计所需的基本指标。基于江边电站引水隧洞沿线区域的地质资料,利用快速拉格朗日分析程序FLAC3D建立了该区域的数值计算模型,使用了随深度变化的侧压力系数以及应力和位移的混合边界条件,通过模拟引水隧洞沿线... 详细信息

初始地应力场是地下洞室设计所需的基本指标。基于江边电站引水隧洞沿线区域的地质资料,利用快速拉格朗日分析程序FLAC3D建立了该区域的数值计算模型,使用了随深度变化的侧压力系数以及应力和位移的混合边界条件,通过模拟引水隧洞沿线不同岩性的岩石、断层破碎带和蚀变带进行正分析计算。根据工程现场实测点的主应力数据,基于径向基函数(RBF)神经网络原理,反演了计算区域的岩体力学参数和初始地应力场。其计算结果与实测地应力值基本吻合,满足精度要求,说明反演结果与工程实际相符,所使用的反演方法是合理的。

关键词：径向基函数神经网络 FLAC3D 岩石力学参数边界条件地应力场反演

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木材的宏观力学模型及断裂机理

北京林业大学学报 2010年第2期32卷 153-156页

作者：田振农张乐文山东大学土建水利学院

通过理论与试验分析相结合的方法,建立木材多尺度力学分析模型,分析木材的宏观力学性质和断裂机理。在假设木材是含裂纹的各向异性材料基础上,建立了断裂力学分析模型,并用该模型研究了含边缘Ⅰ型裂纹的有限大板的应力场和应力强度因子... 详细信息

通过理论与试验分析相结合的方法,建立木材多尺度力学分析模型,分析木材的宏观力学性质和断裂机理。在假设木材是含裂纹的各向异性材料基础上,建立了断裂力学分析模型,并用该模型研究了含边缘Ⅰ型裂纹的有限大板的应力场和应力强度因子;进一步分析了木板紧凑拉伸时裂纹的几何特征对应力强度因子的影响,建立了应力强度因子的无量纲关系式;结合模型试验,得到木材的横纹断裂韧性和顺纹断裂韧性参数。结果表明:裂纹的存在对其附近应力场的影响很大,在张应力情况下容易引起木材的断裂,而且顺纹断裂韧性与横纹断裂韧性的差别很大。

关键词：断裂韧性应力强度因子正交各向异性

Nano high-entropy oxide cathode with enhanced stability for direct borohydride fuel cells

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Journal of Energy Chemistry 2025年第1期100卷 309-316页

作者： lei zhang Lingfeng Kuang Lianke zhang wen Chu Haiying Qin Jing zhang Junjing He Hualiang Ni Hongzhong Chi New Energy Materials Research Center College of Materials and Environmental Engineering Hangzhou Dianzi University School of Materials Science and Engineering Zhejiang University Key Laboratory of MEMS of Ministry of Education School of Integrated Circuits Southeast University

High-entropy materials have become high-activity electrocatalysis owing to their high-entropy effect and multiple active ***,we synthesize a series of carbon-supported nano high-entropy oxides（HEOs/C）,specifically （PtFeCoNiCu）O/C,using a carbothermal shock （CTS） method for application as a cathode catalyst in direct borohydride fuel cells （DBFCs）.The microstructure of the prepared catalysts was characterized by X-ray photoelectron spectroscopy,X-ray absorption fine structure,and transmission electron *** prepared （PtFeCoNiCu）O/C,with particle sizes ranging from 2 to 4 nm,demonstrates 3.94 transferred electrons towards the oxygen reduction reaction in an alkaline environment,resulting in a minimal H2O2yield of 2.6%.Additionally,it exhibits a Tafel slope of 61 mV dec-1,surpassing that of commercial Pt/C (82 mV dec-1).Furthermore,after 40,000 cycles of cyclic voltammetry（CV） testing,the half-wave potential of （PtFeCoNiCu）O/C shows a positive shift of 3 mV,with no notable decline in the limiting current *** （PtFeCoNiCu）O/C is used as a cathode catalyst in DBFCs,the DBFC achieves a maximum power density of 441 mW cm-2at 60°C and sustains a cell voltage of approximately 0.73 V after 52 h at 30°*** findings confirm that HEO/C is a promising cathode catalyst for DBFCs.

关键词： Direct borohydride fuel cells (DBFC)

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基于虚土桩模型的层状地基群桩沉降研究

岩土力学 2017年第8期38卷 2368-2376,2394页

作者：辛冬冬张乐文宿传玺山东大学岩土与结构工程研究中心山东济南250061

群桩中各基桩之间的加筋与遮帘效应和桩端土体变形是群桩沉降计算中的关键部分,极大地影响计算结果的准确性,然而,目前相关的研究仍显不足。采用剪切位移法原理分析了各基桩之间的加筋与遮帘效应,通过荷载传递法原理推导出层状地基土中... 详细信息

群桩中各基桩之间的加筋与遮帘效应和桩端土体变形是群桩沉降计算中的关键部分,极大地影响计算结果的准确性,然而,目前相关的研究仍显不足。采用剪切位移法原理分析了各基桩之间的加筋与遮帘效应,通过荷载传递法原理推导出层状地基土中各基桩桩底、顶之间的沉降与轴力关系式;基于虚土桩模型,探讨了虚土桩长度的影响因素并给出了定量计算公式,得到了层状地基土中各虚土桩顶、底之间的沉降与轴力关系式;利用基桩与虚土桩的边界条件和平衡关系确定柔度系数矩阵,进而根据不同的承台形式求得群桩沉降。工程案例计算表明,理论计算与实测值吻合较好,该方法具有较高的准确性。其研究结果对群桩沉降计算理论的发展具有一定的补充和推动作用。

关键词：群桩沉降虚土桩模型加筋与遮帘效应层状地基柔度系数

Mesh-supported V2O5-WO3/TiO2 nanosheet array catalysts for efficient removal of NOx

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Tungsten 2025年第1期7卷 100-111页

作者： Zhi-Qi zhang Liu Yang wen Luo Vladimir An Jing Li Bao-Dan Liu School of Materials Science and Engineering Northeastern University Foshan Graduate School of Innovation Northeastern University Kizhner Research Center School of Advanced Manufacturing Technologies Tomsk Polytechnic University

The design and synthesis of vanadium-based denitration catalysts with low-temperature activity pose significant challenges in the field of toxic gas *** this study,we have developed a novel approach to fabricate highly efficient V2O5-WO3/TiO2monolithic mesh catalysts for NOxreduction at low ***,TiO2nanosheets with strong adhesion and large surface area were grown on Ti mesh using plasma electrolytic oxidation technology and hydrothermal ***,super-small traces of WO3and V2O5active nano-species were subsequently deposited on TiO2nanosheets using the deposition-precipitation *** to traditional ceramic-based V2O5-WO3/TiO2catalysts,our V2O5-WO3/TiO2monolithic mesh catalyst exhibits superior mechanical performance,excellent thermal conductivity,lower pressure drop,higher utilization of active components,and stronger synergistic ***,the V2O5-WO3/TiO2monolithic mesh catalysts exhibited excellent low-temperature catalytic activity with 98% of NOxconversion at 220℃,and remarkable long-term SO2tolerance and water resistance in the selective catalytic reduction（SCR） of NOxwith *** SCR reaction of tiny V2O5and WO3active species supported on TiO2nanosheets directly demonstrated to follow the Eley-Rideal mechanism by in situ infrared spectra.

关键词： Low temperature activity Monolithic mesh catalysts NH3-SCR SO2 tolerance V2O5-WO3/TiO2

Structural engineering of high-entropy alloys for advanced electrocatalytic reactions

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Tungsten 2025年第1期7卷 1-31页

作者： Qiao Xie Ying-Jie Yu Hai-Jun zhang Ya-Ping Deng wen lei The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Department of Chemical Engineering Waterloo Institute for Sustainable Energy Waterloo Institute for Nanotechnology University of Waterloo

High-entropy alloys(HEAs) have emerged as promising candidates to replace traditional precious metal catalysts,owing to their unique chemical and physical *** review commences by revisiting the fundamental concepts of HEAs,including their synthesis methods and structural control strategies in *** underscores the critical role of meticulously manipulating both macroscopic and microscopic structures of the HEAs to optimize their catalytic performance.A deep understanding of the structure-activity relationship in HEAs across various configurations is pivotal in developing more effective *** review methodically encapsulates the research progress of structural control strategies for HEAs in achieving efficient energy conversion,with the aim of gaining a better understanding of the relationship between structure and *** review concludes by summarizing the current achievements and challenges,and suggestions for potential future directions of HEAs in the fields of energy conversion and environmental purification.

关键词： Electrocatalytic Energy conversion High-entropy alloys Structural modulation