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学者姓名:周剑
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Abstract :
Experimental studies indicated that most rocks exhibit distinct elastic moduli under compressive and tensile loading, leading to intricate stress conditions in rock mass under thermal-mechanical coupling. It is an urgent demand for advanced numerical methods that can simultaneously consider the bi-modular elasticity of rock, thermal-mechanical coupling effects, and thermal cracking behaviors to improve understanding of geological science. The Balanced Interface Method (BIM), a novel bi-modular elastic algorithm is proposed in Particle Flow Code to investigate the thermal-mechanical behavior of bi-modular elastic materials. Firstly, this study introduces the calculation principle of BIM and presents the calibration procedure for bi-modular elastic materials, which is further validated through two case exercises. Subsequently, the thermal-mechanical coupling algorithm is improved by utilizing the Flat-Joint Model (FJM), and a correction method for the position of the compressiontension interface based on BIM for the thermal-mechanical coupling process is introduced, which is then verified by a comprehensive transient heat conduction case with different elastic assumptions. Lastly, a cracking example induced by thermal-mechanical coupling is simulated. The numerical results demonstrate consistency with previous studies and reveal a significant improvement in the thermal cracking behavior of rock, proving the developed algorithm's necessity in investigating the coupled thermal-mechanical problem.
Keyword :
Particle Flow Code (PFC) Particle Flow Code (PFC) Bi-modular elastic Bi-modular elastic Transient heat conduction Transient heat conduction Thermal cracking Thermal cracking Thermal-mechanical coupling Thermal-mechanical coupling
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GB/T 7714 | Peng, Xiao , Zhou, Jian , Zhang, Luqing et al. A novel bi-modular elastic algorithm in particle Flow Code for thermal cracking modeling of rock [J]. | THEORETICAL AND APPLIED FRACTURE MECHANICS , 2024 , 130 . |
MLA | Peng, Xiao et al. "A novel bi-modular elastic algorithm in particle Flow Code for thermal cracking modeling of rock" . | THEORETICAL AND APPLIED FRACTURE MECHANICS 130 (2024) . |
APA | Peng, Xiao , Zhou, Jian , Zhang, Luqing , Dong, Tingfa , Wang, Song , Kong, Yanlong . A novel bi-modular elastic algorithm in particle Flow Code for thermal cracking modeling of rock . | THEORETICAL AND APPLIED FRACTURE MECHANICS , 2024 , 130 . |
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Abstract :
Long-term irrigation promotes the infiltration of water in the thick, stratified loess layer, significantly raising the groundwater table and triggering a series of landslides in loess platform areas. The soil-water characteristic curve (SWCC) of loess buried at different depths affects the unsaturated infiltration process and is intricately connected to the soil's microstructure. The SWCCs, scanning electron microscope (SEMs), and pore size distributions (PSDs) for five sets of undisturbed loess samples at depths ranging from 3.4 to 51.9 m are shown in this paper. The results indicate that the fitting parameter air entry value (AEV) of the SWCC rises from 13.67 kPa to 40.19 kPa as the depth increases from 3.4 to 51.9 m. And the saturated volumetric water content drops by 10.9%, with a notable SWCC shape difference between the transition and residual zones observed. Additionally, the total porosity of undisturbed loess falls by 12% when the depth increases from 3.4 to 51.9 m, while the macropores and mesopores reduce by 3.6% and 12.1%, respectively. These findings highlight the control of the pore structure on the SWCC and emphasize the correspondence between the SWCC and PSD. The conclusions also illustrate that the compaction effect changes the microstructure characteristics of loess, thereby affecting the soil's water retention behavior.
Keyword :
pore size distribution pore size distribution pore structure pore structure unsaturated hydraulic characteristics unsaturated hydraulic characteristics buried depth buried depth undisturbed loess undisturbed loess
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GB/T 7714 | Tan, Ye , Dai, Fuchu , Zhao, Zhiqiang et al. Analysis of Soil-Water Characteristic Curve and Microstructure of Undisturbed Loess [J]. | APPLIED SCIENCES-BASEL , 2024 , 14 (8) . |
MLA | Tan, Ye et al. "Analysis of Soil-Water Characteristic Curve and Microstructure of Undisturbed Loess" . | APPLIED SCIENCES-BASEL 14 . 8 (2024) . |
APA | Tan, Ye , Dai, Fuchu , Zhao, Zhiqiang , Zhou, Jian , Cheng, Wei . Analysis of Soil-Water Characteristic Curve and Microstructure of Undisturbed Loess . | APPLIED SCIENCES-BASEL , 2024 , 14 (8) . |
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Abstract :
Abundant natural fractures (NFs) in hot dry rock (HDR) reservoirs serve as a crucial element in hydraulic fracturing technology and reservoir production. Nevertheless, the interaction mechanism between hydraulic fractures (HFs) and natural fracture networks (NFNs) remains poorly understood. This study combines the novel hydro-grain-based model (hydro-GBM) and discrete fracture network (DFN) model to investigate the effects of insitu stress, fracture number, and fracture length on hydraulic fracturing behaviors in mineral-scale granite with NFNs. Results indicate that as the complexity of NFs increases, the stress shadow effect is amplified during HF propagation, while the spatial arrangement of NFs governs the propagation of secondary paths. Additionally, a downward trend is observed in average activity levels of acoustic emission (AE) events and proportions of large events within NFs and matrix. Damage and activation degrees in both NFs and matrix decrease with an increase in the number of NFs. The inability of main hydraulic paths to propagate over long distances can be attributed to the dispersion of fracturing fluid and the rapid decay of pressure within densely distributed, short NFs. These numerical findings shed light on the process of HFs activating NFNs and provide valuable insights for enhancing heat extraction efficiency in HDR reservoirs.
Keyword :
Natural fracture network Natural fracture network Particle flow code Particle flow code Hydraulic fracturing Hydraulic fracturing Grain -based model Grain -based model Hot dry rock Hot dry rock Fluid -solid coupling algorithm Fluid -solid coupling algorithm
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GB/T 7714 | Wang, Song , Zhou, Jian , Zhang, Luqing et al. Numerical insight into hydraulic fracture propagation in hot dry rock with complex natural fracture networks via fluid-solid coupling grain-based modeling [J]. | ENERGY , 2024 , 295 . |
MLA | Wang, Song et al. "Numerical insight into hydraulic fracture propagation in hot dry rock with complex natural fracture networks via fluid-solid coupling grain-based modeling" . | ENERGY 295 (2024) . |
APA | Wang, Song , Zhou, Jian , Zhang, Luqing , Han, Zhenhua , Kong, Yanlong . Numerical insight into hydraulic fracture propagation in hot dry rock with complex natural fracture networks via fluid-solid coupling grain-based modeling . | ENERGY , 2024 , 295 . |
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Abstract :
As anthropogenic antibiotics, quinolones, e.g., ofloxacin have adverse impacts on ecological systems and human heaths. The removal of quinolones is of great importance, and adsorption techniques have been widely used to remove this hazardous contaminant. However, a robust and easy-operating adsorbent is still emergently required due to the complex chemical structure of quinolones. In this study, we successfully synthesized the promising metallic carbons (MCs) containing carbon nanotubes and cobalt nanoparticles by carbonizing Zn/Co-ZIF at 900 degrees C. Three different molar ratios of Co and Zn were applied to optimize the adsorption capacity on ofloxacin (OFL). Results showed MC with molar ratio of Co and Zn at 3:1 (Co-CNT/NPC3/1) achieved the maximal adsorption capacity to 118.3 mg g-1. Its adsorption performance was satisfied in the pH range from 5 to 9 and ionic strengths at 0.01 M. The main mechanisms for these adsorptions were identified as electrostatic attraction, metal coordination and pi-pi EDA. Removal efficiencies of quinolones higher than 68 mg g-1 indicated the strong feasibility of this adsorbent for wastewater treatments. The regeneration of Co-CNT/NPC3/1 at 600 degrees C allowed its at least 4-time reusability and its magnetic property enabled external magnets to recycle it from real environments.
Keyword :
Magnetic separation Magnetic separation Adsorption Adsorption Zn Zn Co zeolitic imidazolate frameworks Co zeolitic imidazolate frameworks Metallic carbides Metallic carbides
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GB/T 7714 | Liang, Yixuan , Zhang, Qiyu , Li, Sumei et al. Highly efficient removal of quinolones by using the easily reusable MOF derived-carbon [J]. | JOURNAL OF HAZARDOUS MATERIALS , 2022 , 423 . |
MLA | Liang, Yixuan et al. "Highly efficient removal of quinolones by using the easily reusable MOF derived-carbon" . | JOURNAL OF HAZARDOUS MATERIALS 423 (2022) . |
APA | Liang, Yixuan , Zhang, Qiyu , Li, Sumei , Fei, Jiaying , Zhou, Jian , Shan, Saisai et al. Highly efficient removal of quinolones by using the easily reusable MOF derived-carbon . | JOURNAL OF HAZARDOUS MATERIALS , 2022 , 423 . |
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Abstract :
岩体工程计算分析中结构面刚度系数是至关重要的力学参数,计算分析的精度和可靠程度与这个参数密不可分,结构面刚度系数取值仍然是一个难点.岩体中应力波传播至结构面处将会发生反射和透射现象,利用应力波透射系数可反演结构面动态刚度系数.本文从细观力学角度运用颗粒离散元方法,开发分段线性接触模型及应力波吸收边界模型,开展宏观岩体中应力波传播的模拟,结合准静态压缩试验模拟,研究了较为平直的岩体结构面分别在不同正应力条件下的动、静态刚度系数的变化特征.模拟结果表明:(1)利用C++语言开发的分段线性接触模型很好地实现了结构面非线性变形特征的模拟;(2)基于颗粒离散元方法能够准确地反映岩体中应力波传播规律,应力波通过不同刚度结构面的透射系数与理论解一致;(3)在离散颗粒模型中加入黏滞吸收边界条件很好地实现了在有限尺寸模型中远场应力波传播模拟;(4)在岩体模型中结构面接触部位运用分段线性接触模型,通过模拟应力波传播与单轴压缩试验分别获得了一致性较好的结构面动、静态刚度系数,结构面动/静态刚度系数之比值约为1.0.本文对岩体中结构面刚度的测试和取值具有重要的指导意义.
Keyword :
黏结颗粒模型 黏结颗粒模型 吸收边界模型 吸收边界模型 结构面刚度系数反演 结构面刚度系数反演 接触模型 接触模型 应力波传播 应力波传播
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GB/T 7714 | 周剑 , 王彦兵 , 张路青 et al. 基于离散颗粒模型的岩体结构面动-静态刚度系数对比的数值模拟研究 [J]. | 工程地质学报 , 2021 , 29 (1) : 25-33 . |
MLA | 周剑 et al. "基于离散颗粒模型的岩体结构面动-静态刚度系数对比的数值模拟研究" . | 工程地质学报 29 . 1 (2021) : 25-33 . |
APA | 周剑 , 王彦兵 , 张路青 , 金永军 , 涂新斌 . 基于离散颗粒模型的岩体结构面动-静态刚度系数对比的数值模拟研究 . | 工程地质学报 , 2021 , 29 (1) , 25-33 . |
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Abstract :
基于离散颗粒模型的岩体结构面动-静态刚度系数对比的数值模拟研究
Keyword :
黏结颗粒模型 黏结颗粒模型 吸收边界模型 吸收边界模型 结构面刚度系数反演 结构面刚度系数反演 接触模型 接触模型 应力波传播 应力波传播
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GB/T 7714 | 周剑 , 王彦兵 , 张路青 et al. 基于离散颗粒模型的岩体结构面动-静态刚度系数对比的数值模拟研究 [J]. | 周剑 , 2021 , 29 (1) : 25-33 . |
MLA | 周剑 et al. "基于离散颗粒模型的岩体结构面动-静态刚度系数对比的数值模拟研究" . | 周剑 29 . 1 (2021) : 25-33 . |
APA | 周剑 , 王彦兵 , 张路青 , 金永军 , 涂新斌 , 工程地质学报 . 基于离散颗粒模型的岩体结构面动-静态刚度系数对比的数值模拟研究 . | 周剑 , 2021 , 29 (1) , 25-33 . |
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Abstract :
本文研究了硫铝酸盐水泥(CSA)在盐酸和硫酸环境下的力学性能演化规律,并探究了其抗酸侵蚀机理.分别测试了水和酸溶液养护的CSA胶砂试件的抗折强度,计算了CSA的抗酸侵蚀系数.采用XRD、TGA、CT和SEM分析了酸侵蚀导致的产物种类和数量变化,表征了微观结构演化过程.结果表明:与普通硅酸盐水泥(OPC)相比,CSA在盐酸和硫酸中抗折强度损失率更低,具有更好的抗盐酸和硫酸侵蚀能力;CSA主要水化产物(钙矾石)比OPC主要水化产物(氢氧化钙和硅酸钙凝胶)更难与酸反应,因此抗酸侵蚀能力更强.盐酸与硫酸对CSA的侵蚀机制略有不同,盐酸对CSA的侵蚀过程实质上为氢离子对CSA水化产物钙矾石的酸解,硫酸对CSA的侵蚀则是氢离子和硫酸根离子的共同作用.
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GB/T 7714 | 齐秋霖 , 周健 , 葛仲熙 et al. 硫铝酸盐水泥抗酸侵蚀性能与机理研究 [J]. | 硅酸盐通报 , 2021 , 40 (8) : 2508-2514,2533 . |
MLA | 齐秋霖 et al. "硫铝酸盐水泥抗酸侵蚀性能与机理研究" . | 硅酸盐通报 40 . 8 (2021) : 2508-2514,2533 . |
APA | 齐秋霖 , 周健 , 葛仲熙 , 李辉 , 徐名凤 , 陈智丰 et al. 硫铝酸盐水泥抗酸侵蚀性能与机理研究 . | 硅酸盐通报 , 2021 , 40 (8) , 2508-2514,2533 . |
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Abstract :
Enhancing electrocatalytic water splitting performance by modulating the intrinsic electronic structure is of great importance. Here, porous bimetallic oxide and chalcogenide nanosheets grown on carbon paper denoted as NiCo2X4/CP (X = O, S, and Se) are prepared to demonstrate how the anion components affect the electronic structures and thereby disclose the correlation between their intermediates interaction and catalytic activities. The experimental characterization and theoretical calculation demonstrate that Se and S substitution can promote the ratio of Co3+/Co2+ and thereby modulate the electronic structure accompanied with the upshift of d band centers, which not only enhance the inner conductivity but also regulate the interaction between the catalyst surface and intermediates, especially for the adsorption of absorbed H and hydroperoxy intermediates towards respective hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As a result, a full alkaline electrolyzer using NiCo2Se4/CP and NiCo2S4/CP as cathode and anode delivers a low voltage of 1.51 V at 10 mAcm(-2), which is comparable even superior to most transition metal-based electrolyzers.
Keyword :
bimetallic chalcogenide bimetallic chalcogenide electrocatalytic overall water splitting electrocatalytic overall water splitting high valence Co3+ high valence Co3+ intermediates interaction intermediates interaction electronic structure electronic structure
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GB/T 7714 | Zhou, Jian , Dou, Yibo , He, Tao et al. Revealing the effect of anion-tuning in bimetallic chalcogenides on electrocatalytic overall water splitting [J]. | NANO RESEARCH , 2021 , 14 (12) : 4548-4555 . |
MLA | Zhou, Jian et al. "Revealing the effect of anion-tuning in bimetallic chalcogenides on electrocatalytic overall water splitting" . | NANO RESEARCH 14 . 12 (2021) : 4548-4555 . |
APA | Zhou, Jian , Dou, Yibo , He, Tao , Zhou, Awu , Kong, Xiang-Jing , Wu, Xue-Qian et al. Revealing the effect of anion-tuning in bimetallic chalcogenides on electrocatalytic overall water splitting . | NANO RESEARCH , 2021 , 14 (12) , 4548-4555 . |
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Abstract :
本文依据分布于全国的6824个钻孔数据,按照双参数的不同取值,将GB50011—2010《建筑抗震设计规范》(以下简称中国建抗规)的场地类别进一步划分为更加同质的子类,分析了双参数体系对场地分类结果的影响,建立了每个子类与美国《NEHRP对新建建筑和结构物的推荐地震条款》(National Earthquake Hazards Reduction Program Recommended Provisions for Seismic Regulations for New Buildings and Other Structures,以下简称美国建抗规)的场地类别的对应关系,并对比分析中、美建抗规的场地类别差异,在此基础上建立了中国建抗规与美国建抗规场地类别相互转换的概率表达.研究结果表明:用vS20近似表示中国场地分类标准的等效剪切波速并不可靠;中国建抗规中Ⅱ类场地和Ⅲ类场地内部不同子类与美国建抗规中场地类别的对应关系截然不同;中国建抗规中覆盖层厚度有效地区分了浅部波速类似而深部波速不同的场地;中国建抗规的Ⅱ类和Ⅲ类场地主体均对应美国建抗规的D类场地,中国Ⅱ类场地略偏对应美国C类场地,中国Ⅲ类场地略偏对应美国E类场地;中国Ⅳ类场地对应美国E类场地,绝大多数美国C类和D类场地均对应中国Ⅱ类场地,说明中国Ⅱ类场地的范围极宽.
Keyword :
场地类别 场地类别 对比分析 对比分析 换算关系 换算关系 抗震设计规范 抗震设计规范
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GB/T 7714 | 周健 , 李小军 , 李亚琦 et al. 中美建筑抗震设计规范中工程场地类别的对比和换算关系 [J]. | 地震学报 , 2021 , 43 (4) : 521-532 . |
MLA | 周健 et al. "中美建筑抗震设计规范中工程场地类别的对比和换算关系" . | 地震学报 43 . 4 (2021) : 521-532 . |
APA | 周健 , 李小军 , 李亚琦 , 亢川川 . 中美建筑抗震设计规范中工程场地类别的对比和换算关系 . | 地震学报 , 2021 , 43 (4) , 521-532 . |
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This paper studies the dynamic behaviors of a magnetically coupled oscillator with two degrees-of-freedom. For the certain parameter combinations, the target component (TC), which is excited by a base movement, enters the saturated steady-state responses. Another component, which is called as the spatially constrained system (SCS), is considered as an energy absorber pumping out of the energy from the TC under 1:3 internal resonance. The governing equations of motion are derived using a magnetic dipole model and then are solved with the method of multiple scales. The energy distributions between the TC and SCS can vary with the base movement amplitude and excitation frequency. The saturation behavior is found and used for constraining the moving amplitude of an excited system. The bifurcation diagrams reveal the complex and interesting responses when the excitation frequency and amplitude change. The results include the comparisons among the analytical predictions, numerical simulations, and experimental tests. For the purpose of suppressing the primary resonance, the present system effectively transf er the energy from the excited component. The jumping and saturation phenomena are found in the experiments and the changes in the spectrum of two steady-state responses are also observed. (C) 2020 Elsevier Ltd. All rights reserved.
Keyword :
Internal resonance Internal resonance Magnetic coupled oscillator Magnetic coupled oscillator Spatially constrained system Spatially constrained system Method of multiple scales Method of multiple scales Resonance suppression Resonance suppression
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GB/T 7714 | Zhou, J. , Zhang, W. , Wang, X. S. et al. Primary resonance suppression of a base excited oscillator using a spatially constrained system: Theory and experiment [J]. | JOURNAL OF SOUND AND VIBRATION , 2021 , 496 . |
MLA | Zhou, J. et al. "Primary resonance suppression of a base excited oscillator using a spatially constrained system: Theory and experiment" . | JOURNAL OF SOUND AND VIBRATION 496 (2021) . |
APA | Zhou, J. , Zhang, W. , Wang, X. S. , Mann, B. P. , Dowell, E. H. . Primary resonance suppression of a base excited oscillator using a spatially constrained system: Theory and experiment . | JOURNAL OF SOUND AND VIBRATION , 2021 , 496 . |
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