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Microdamage study of granite under thermomechanical coupling based on the particle flow code

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Frontiers of Structural and Civil Engineering 2023年第9期17卷 1413-1427页

作者： Chong SHI yiping zhang Yulong zhang Xiao CHEN Junxiong YANG Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing 210098China College of Civil and Transportation Engineering Hohai UniversityNanjing 210098China Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines College of Resources and Civil EngineeringNortheastern UniversityShenyang 110819China Department of Civil and Mineral Engineering University of TorontoToronto M5S1A1Canada

The thermomechanical coupling of rocks refers to the interaction between the mechanical and thermodynamic behaviors of rocks induced by temperature *** study of this coupling interaction is essential for understanding the mechanical and thermodynamic properties of the surrounding rocks in underground *** this study,an improved temperature-dependent linear parallel bond model is introduced under the framework of a particle flow simulation.A series of numerical thermomechanical coupling tests are then conducted to calibrate the micro-parameters of the proposed model by considering the mechanical behavior of the rock under different thermomechanical *** agreement between the numerical results and experimental data are obtained,particularly in terms of the compression,tension,and elastic responses of *** this improved model,the thermodynamic response and underlying cracking behavior of a deep-buried tunnel under different thermal loading conditions are investigated and discussed in detail.

关键词： thermomechanical coupling effect granite improved linear parallel bond model thermal property particle flow code

Effective removal of Sb(V)from aqueous solutions by micro-electrolysis with composite scrap iron-manganese as filler

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第6期25卷 516-524页

作者： Shangkun DING Saihua HUANG yiping zhang Yongchao ZHOU Institute of Municipal Engineering Zhejiang UniversityHangzhou310058China Zhejiang University of Water Resources and Electric Power Hangzhou310018China

Micro-electrolysis(ME)technology is investigated for improving the efficiency of removal of pentavalent antimony(Sb(V))from the *** this study,an ME system composed of scrap iron filings,waste manganese fillings,and activated carbon(Fe-Mn-C ME)was used to efficiently remove Sb(V).The results proved that,compared with conventional iron-carbon micro-electrolysis(Fe-C ME),Fe-Mn-C ME significantly enhances the removal rate of Sb(V)when the hydraulic retention time is 10–24 *** Fe-Mn flocs produced by this system were analyzed using X-ray diffraction(XRD),energy-dispersive X-ray spectroscopy(EDS),X-ray photoelectron spectroscopy(XPS),and Brunauer-Emmett-Teller(BET)surface area analysis,which revealed that the flocs were mostly Mn-substituted FeOOH and had a relatively larger specific surface area,providing better adsorption ***,it was found that the removal rate of Sb(V)decreased as the iron-carbon mass ratio increased,while it first increased and then decreased as the manganese content *** reduction of Fe(III)was accelerated with an increase in the addition of manganese,leading to an increase in the concentration of Fe(II).The electron transfer and the formation of Fe(II)were facilitated by the potential difference between manganese and carbon,as well as by the formation of microcells between iron and manganese,which improved the reduction ability of Sb(V).From our thorough investigation and research,this is the first report that has proposed Fe-Mn-C ME for removing *** provides a novel approach and technological support for removing Sb(V)efficiently.

关键词： Antimony Iron Manganese Micro-electrolysis(ME) Electrochemistry Mechanism

Some remarks on invertible substitutions on three letter alphabet

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Chinese Science Bulletin 1999年第19期44卷 1755-1760页

作者： Zhixiong Wen yiping zhang Wuhan Univ Dept Math State Key Lab Software Engineer Wuhan 430072 Peoples R China

By introducing the notion of 'prime substitution' it is shown that the set of invertible substitutions over an alphabet of more than three letters is not finitely generated. Some examples are given.

关键词： invertible substitution prime substitution.

A method of separating blended images in space debris observation

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Science China(Physics,Mechanics & Astronomy) 2012年第10期55卷 1945-1951页

作者： SUN RongYu ZHAO ChangYin zhang yiping Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008China Key Laboratory of Space Object and Debris Observation Chinese Academy of SciencesNanjing 210008China Graduate University of Chinese Academy of Sciences Beijing 100049China

Due to the relative movement between space debris and background stars,the blending of objects and stars is ineluctable through *** brings down position accuracy of objects and even makes the tracking break down in worse *** view of the difference of geometry between stars and objects in space debris observation,a technique for separating blended objects based on mathematical morphology is ***'s sufficiently flexible to be applied in image processing,and the blending images can be separated effectively with a high degree of centroid precision.

关键词： space debris image processing mathematical morphology

Semisolid-rolling and annealing process of woven carbon fibers reinforced Al-matrix composites

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Journal of Materials Science & Technology 2017年第7期33卷 623-629页

作者： Junjia zhang Shichao Liu yiping Lu Li Jiang Yubo zhang Tingju Li Key Laboratory of Solidification Control and Digital Preparation Technology （Liaoning Province） School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China

Semisolid-rolling method was successfully developed to prepare the Ni-coated woven carbon fibers reinforced Al-matrix composite. Due to the appropriate matrix flowability and rolling pressure, the Al-matrix could infiltrate into the woven fibers sufficiently and attach to the reinforcements closely forming a smooth interface. The rolling speed of 4 rad/min offered a subtle equilibrium between the heat transfer and the material deformation. The covering matrix should be controlled at semisolid state to provide a better infiltration behavior and a protective effect on the carbon fibers. With the addition of fibers, an improvement for more than 25% was obtained in the bending strength of the materials. Furthermore, the woven carbon fibers could strengthen the composite in multiple directions, rather than only along the fiber longitudinal directions. The annealing process promoted the Ni coating to react with and to diffuse into the matrix, resulted in an obvious increase of the bending strength.

关键词： Metal-matrix composites Woven carbon fiber Semisolid-rolling process Annealing Mechanical property

Study of CO_2 Hydrogenation to Methanol over CU-V/γ-Al_2O_3 Catalyst

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Journal of Natural Gas Chemistry 2007年第1期16卷 12-15页

作者： yiping zhang Jinhua Fei Yingmin Yu Xiaoming Zheng Institute of Catalysis Xixi Campus Zhejiang University Hangzhou 310028 Zhejiang China Department of Chemistry Zhejiang Education Institute Hangzhou 310012 Zhejiang China

The effect of vanadium addition to Cu/γ-Al2O3 catalyst used in the hydrogenation of CO2 to produce methanol was studied. It was found that the catalytic performance of the Cu-based catalyst improved after V addition. The influence of reaction temperature, space velocity and the molar ratio of H2 to CO2 on the performance of 12%Cu-6%V/γ-Al2O3 catalyst were also studied. The results indicated that the best conditions for reaction were as follows： 240 ℃, 3600 h^-1 and a molar ratio of H2 to 602 of 3：1. The results of XRD and TPR characterization demonstrated that the addition of V enhanced the dispersion of the supported CuO species, which resulted in the enhanced catalytic performance of Cu-V/γ-Al2O3 binary catalyst.

关键词： CO2 hydrogenation methanol copper vanadium

Sedimentary Paleoenvironment of the Eastern Hexi Corridor, NW China: Constraints from Chert Geochemistry and Sedimentary Analysis of Early Paleozoic Strata

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Acta Geologica Sinica(English Edition) 2020年第4期94卷 1223-1237页

作者： zhang yiping CHEN Xuanhua AVZUZA zhang Beihang ZHAO Heng Chinese Academy of Geological Sciences Beijing 100037China Nevada Bureau of Mines and Geology University of NevadaReno89557USA Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

The eastern Hexi Corridor, northwest China, is located at the tectonic junction of the Alxa Block, the North China Craton, and the Qinling-Qilian Orogen. The early Paleozoic Xiangshan Group record critical information regarding paleoenvironment, paleoclimate and paleotectonic setting, from which we here present a focused study on the chert beds within the Xiangshan Group. Through field mapping, microstructural observation, whole-rock geochemistry analyses and detrital zircon dating, we suggest that the Xiangshan Group chert was deposited along a passive continental margin, formed primarily through biological activity with minor hydrothermal influence and terrestrial input. The characteristics of the chert support a low latitude sedimentary paleoenvironmental origin, and reveal the fact that the Alxa Block was separated from the North China craton, while emerged some paleogeographic affinity with the Qilian region in the Middle-Late Cambrian.

关键词： geochemistry sedimentary paleoenvironment Early Paleozoic Xiangshan Group chert Hexi Corridor

Mesozoic-Cenozoic Multi-Stage Intraplate Deformation Events in the Langshan Region and their Tectonic Implications

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Acta Geologica Sinica(English Edition) 2014年第1期88卷 78-102页

作者： zhang Jin LI Jinyi LI Yanfeng QI Wenhua zhang yiping Institute of Geology Chinese Academy of Geological Sciences National Earthquake Response Support Service Institute of Geology Chinese Earthquake Administration

In the Langshan region, northwestern China, marked multi-stage intraplate deformation events have occurred since the Mesozoic, including（1） northeast-striking ductile left-lateral strike slip during the Middle-Late Triassic, which is closely related to the collision between the North China and the Yangtze plates;（2） top-to-the-southeast thrust with northwest-southeast trending maximum compression during the Late Jurassic;（3） nearly eastward detachment during the Early Cretaceous;（4） top-to-the-northwest thrust with northwest-southeast trending maximum compression during the Late Cretaceous and Early Cenozoic;（5） northeast-striking brittle left-lateral strike slip with nearly north-south trending maximum compression; and（6） northwest-southeast extension during the Middle-Late Cenozoic. All these deformation events belong to the intraplate deformation across the entire Central Asian region and respond to the tectonic events along the plate boundaries or deep tectonics. The structures developed in early events in the crust were the most important factors controlling the later deformation styles, and few new structures have later developed. Based on previous research and our results, the paleostress inversion in the Langshan region shows that the Mesozoic intraplate deformations in the study region mainly resulted from the tectonic events from the Paleo-Pacific region and have no or a weak relation to the Tethys region. During the Late Jurassic, the maximum compression from the Mongolia-Okhotsk region cannot be excluded. The Langshan region is the bridge between southern Mongolia and the western Ordos tectonic belt and is thus important to understand the nature and relationship between both regions.

关键词： Langshan intraplate deformation Mesozoic Cenozoic North China Craton Alxa block

A study on Pb isotopic characteristics of raw bauxite in western Guangxi,China

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Chinese Journal Of Geochemistry 2012年第3期31卷 323-326页

作者： LIU Qinzhi WU Qianhong zhang yiping Continuing Education College of Guizhou University Guiyang 550001China School of Geoscience and Environmental Engineering of Central South University Changsha 410083China Guizhou University Guiyang 550003China

The Pb isotopic composition of ores is one of the important approaches to trace the ore *** has not yet been applied to research on bauxite ore so *** current research on bauxite deposits in western Guangxi,China,seldom focuses on raw bauxite and studies on raw bauxite are mostly at *** study is the first to apply Pb isotope data to tracing bauxite ore *** Pb isotopic compositions of ore and rock samples from the Nadou and Taiping mining districts are projected on the Doe and Zartman plumbotectonic models and the results showed that the ore resources are different for the two mines.

关键词：铅同位素组成中国广西铝土矿原材料同位素特征西部岩石样品矿石