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学者姓名:周剑
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摘要 :
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.
关键词 :
Adsorption Adsorption Co zeolitic imidazolate frameworks Co zeolitic imidazolate frameworks Magnetic separation Magnetic separation Metallic carbides Metallic carbides Zn Zn
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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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摘要 :
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.
关键词 :
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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摘要 :
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
关键词 :
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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摘要 :
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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摘要 :
Employing extrapolation models to estimate the time-averaged shear-wave velocity to 30 m (V-S30) from a shallow borehole profile is an effective way to expand the V-S30 data volume and a necessary initial step for developing V-S30 proxy models. Past extrapolation model studies have relied only on shallow borehole shear-wave velocity (V-S) profiles to estimate V-S30. In this study, we enhance the model by accounting for additional parameters including location slope, geologic age, and geotechnical class. We first compile a new borehole profile database (BPDB) that contains information about 8831 boreholes in China. Using this BPDB, we analyze the V-S characteristics of strata for various location slopes, geologic ages, and geotechnical classes. The result shows that the location slope and geologic age have significantly different effects on the V-S characteristics, whereas the differences for sand, silt, and clay are small. We build a parameter classification scheme that classifies the location slope into six groups, the geologic age into seven hierarchical types, and the geotechnical class into four hierarchical types. This scheme ensures that each group/type has its distinctive V-S characteristic. We evaluate five existing V-S models and choose the model that shows the best performance on the BPDB as the "prototype" model. We classify the BPDB boreholes by the parameter classification scheme and use the form of "prototype" model to develop a parametrical model that consists of 33 single-parameter-value models. For a shallow borehole (< 30 m), if its location slope, geologic age, or geotechnical class is available besides its V-S profile, applying the parametrical model will get more accurate estimated V-S30 and model uncertainty estimation than those of existing models that only utilize the information of the V-S profile.
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GB/T 7714 | Zhou, Jian , Li, Xiaojun , Dai, Zhijun et al. Parametrical Model for Estimating from Shallow Borehole Profiles Using a Database for China [J]. | BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA , 2021 , 111 (3) : 1199-1220 . |
MLA | Zhou, Jian et al. "Parametrical Model for Estimating from Shallow Borehole Profiles Using a Database for China" . | BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA 111 . 3 (2021) : 1199-1220 . |
APA | Zhou, Jian , Li, Xiaojun , Dai, Zhijun , Chen, Kun . Parametrical Model for Estimating from Shallow Borehole Profiles Using a Database for China . | BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA , 2021 , 111 (3) , 1199-1220 . |
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摘要 :
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.
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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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摘要 :
Despite numerous inherent merits of metal-organic frameworks (MOFs), structural fragility has imposed great restrictions on their wider involvement in many applications, such as in catalysis. Herein, a strategy for enhancing stability and enabling functionality in a labile Zr(IV)-MOF has been proposed by in situ porphyrin substitution. A size- and geometry-matched robust linear porphyrin ligand 4,4'-(porphyrin-5,15-diyl)dibenzolate (DCPP2- ) is selected to replace the 4,4'-(1,3,6,8-tetraoxobenzo[lmn][3,8]phenanthroline-2,7(1H,3H,6H,8H)-diyl)dibenzoate (NDIDB2- ) ligand in the synthesis of BUT-109(Zr), affording BUT-110 with varied porphyrin contents. Compared to BUT-109(Zr), the chemical stability of BUT-110 series is greatly improved. Metalloporphyrin incorporation endows BUT-110 MOFs with high catalytic activity in the photoreduction of CO2 , in the absence of photosensitizers. By tuning the metal species and porphyrin contents in BUT-110, the resulting BUT-110-50%-Co is demonstrated to be a good photocatalyst for selective CO2 -to-CO reduction, via balancing the chemical stability, photocatalytic efficiency, and synthetic cost. This work highlights the advantages of in situ ligand substitution for MOF modification, by which uniform distribution and high content of the incoming ligand are accessible in the resulting MOFs. More importantly, it provides a promising approach to convert unstable MOFs, which mainly constitute the vast MOF database but have always been neglected, into robust functional materials.
关键词 :
in situ ligand substitution in situ ligand substitution metal-organic frameworks metal-organic frameworks photocatalytic CO 2 reduction photocatalytic CO 2 reduction porphyrin ligands porphyrin ligands stability enhancement stability enhancement
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GB/T 7714 | Kong Xiang-Jing , He Tao , Zhou Jian et al. In Situ Porphyrin Substitution in a Zr(IV)-MOF for Stability Enhancement and Photocatalytic CO2 Reduction. [J]. | Small , 2021 : e2005357 . |
MLA | Kong Xiang-Jing et al. "In Situ Porphyrin Substitution in a Zr(IV)-MOF for Stability Enhancement and Photocatalytic CO2 Reduction." . | Small (2021) : e2005357 . |
APA | Kong Xiang-Jing , He Tao , Zhou Jian , Zhao Chen , Li Tong-Chuan , Wu Xue-Qian et al. In Situ Porphyrin Substitution in a Zr(IV)-MOF for Stability Enhancement and Photocatalytic CO2 Reduction. . | Small , 2021 , e2005357 . |
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摘要 :
Developing efficient photocatalysts for CO2 reduction into value-added chemical feedstocks is of significance. Heterojunction photocatalysts are promising candidates but still suffering from the insufficient electron-hole pair separation issues. Herein, a strategy that dual metal–organic frameworks (MOFs) template-directed fabrication of carbon-supported heterojunction, C-In2O3@MO (MO = ZnO, Co3O4, and ZnCo2O4) with tunable band matching structure was developed. The resultant hollow- structured C-In2O3@ZnCo2O4 shows high CO2 reduction activity towards CO (44.1 μmol g1 h−1) with a selectivity of 66%. The superior performance of this material could be ascribed to the suitable energy band matching and efficient internal charge transfer on p-n heterojunction, which facilitates electron-hole separation. Meanwhile, the hollow cavity not only improved light-harvesting capability through multiple light reflection and scattering in the internal voids but also provided large surface area for exposing active sites to promoting the activation of CO2. This study thus proposes a feasible approach to adjust the heterojunction structure of photocatalysts to achieve efficient CO2 reduction reaction. © 2021 Elsevier B.V.
关键词 :
Carbon dioxide Carbon dioxide Charge transfer Charge transfer Fabrication Fabrication Heterojunctions Heterojunctions II-VI semiconductors II-VI semiconductors Indium compounds Indium compounds Light reflection Light reflection Zinc oxide Zinc oxide
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GB/T 7714 | Zhao, Chen , Zhou, Awu , Dou, Yibo et al. Dual MOFs template-directed fabrication of hollow-structured heterojunction photocatalysts for efficient CO2 reduction [J]. | Chemical Engineering Journal , 2021 , 416 . |
MLA | Zhao, Chen et al. "Dual MOFs template-directed fabrication of hollow-structured heterojunction photocatalysts for efficient CO2 reduction" . | Chemical Engineering Journal 416 (2021) . |
APA | Zhao, Chen , Zhou, Awu , Dou, Yibo , Zhou, Jian , Bai, Jinquan , Li, Jian-Rong . Dual MOFs template-directed fabrication of hollow-structured heterojunction photocatalysts for efficient CO2 reduction . | Chemical Engineering Journal , 2021 , 416 . |
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摘要 :
Mineral grain size heterogeneity is one of the fundamental reasons leading to differences in rock mechanical behaviours. Several indices have been proposed to quantify grain size heterogeneity, however, the applicability of the existing indices is limited due to various preconditions. An improved grain size heterogeneity index H-e was proposed in this study. By comparing with the previous index, the improved index was proved to be more applicable for analysing rock mechanical properties. Through a series of grain-based model (GBM), the grain size heterogeneity effect, material heterogeneity effect and mineral content effect were further discussed. For a simple grain size heterogeneity effect, the crack initiation stress, damage stress, peak stress and crack initiation stress ratio of rock decreased linearly as the improved index H-e increased. After accounting for the material heterogeneity effect, the above characteristic stresses and elastic modulus decreased. A significant material heterogeneity effect and mineral content effect will impact the linear correlation between the rock macromechanical parameters and the H-e index. When the axial stress was low, the grain size heterogeneity had little effect on the number of microcracks, but this heterogeneity became the main factor affecting the evolution of microcracks as the axial stress increased. The number of intragrain tensile cracks increases and the number of intergrain shear cracks decreases with increasing H-e, when the axial stress reached the rock peak strength. Besides, the combined effects of material heterogeneity and mineral content may control the type and number of microcracks, further weakening the effect of grain size heterogeneity.
关键词 :
Alxa granite Alxa granite Grain-based modelling Grain-based modelling Grain size heterogeneity Grain size heterogeneity Heterogeneity index Heterogeneity index Particle flow code Particle flow code
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GB/T 7714 | Han, Zhenhua , Zhang, Luqing , Azzam, Rafig et al. A statistical index indicating the degree and mechanical effects of grain size heterogeneity in rocks [J]. | ENGINEERING GEOLOGY , 2021 , 293 . |
MLA | Han, Zhenhua et al. "A statistical index indicating the degree and mechanical effects of grain size heterogeneity in rocks" . | ENGINEERING GEOLOGY 293 (2021) . |
APA | Han, Zhenhua , Zhang, Luqing , Azzam, Rafig , Zhou, Jian , Wang, Song . A statistical index indicating the degree and mechanical effects of grain size heterogeneity in rocks . | ENGINEERING GEOLOGY , 2021 , 293 . |
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摘要 :
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.
关键词 :
bimetallic chalcogenide bimetallic chalcogenide electrocatalytic overall water splitting electrocatalytic overall water splitting electronic structure electronic structure high valence Co3+ high valence Co3+ intermediates interaction intermediates interaction
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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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