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地聚合物 2

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Establishing two-stage interaction between fly ash and NaOH by X-ray and infrared analyses

Bhagwanjee JHA,Nevin KOSHY,Devendra Narain SINGH

《环境科学与工程前沿（英文）》 2015年第9卷第2期页码 216-221 doi: 10.1007/s11783-014-0630-8

摘要： The interaction of the fly ash and NaOH, in an open reflux hydrothermal system at 100°C, has been explored by several researchers and formation of fly ash zeolites has been confirmed based on the X-ray diffraction analysis of the residues. However, this method does not reveal much about the characteristic transitions (viz. elemental, electro-negativity and cation exchange capacity) of the residues. In this situation, resorting to Fourier transform-infrared radiation (FT-IR) spectroscopy on the residues obtained from two-stage hydrothermal treatment process, described in this manuscript, appears to be a novel idea to establish transitions in chemical bonds (viz., -Si-OH-Al-, OH-Na, OH-Al-), crystallinity and cation exchange capacity of these residues. Based on extensive studies, it has been demonstrated that FT-IR spectroscopy is extremely useful for 1) detection of chemical bonds in the residues, 2) evaluation of zeolites in the residues and 3) also establishing the superiority of the two-stage interaction of the fly ash with NaOH for synthesizing better fly ash zeolites (viz., Na-P1 and Hydroxysodalte) as compared to those obtained from the conventional single-stage treatment of the fly ash.

关键词： hydrothermal treatment alkali activation fly ash zeolites X-ray diffraction (XRD) and Fourier transform-infrared radiation (FT-IR) spectroscopy

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Layered alkali titanates (ATiO): possible uses for energy/environment issues

《能源前沿（英文）》 2021年第15卷第3期页码 631-655 doi: 10.1007/s11708-021-0776-6

摘要： Uses of layered alkali titanates (A₂Ti_nO₂_n₊₁; Na₂Ti₃O₇, K₂Ti₄O₉, and Cs₂Ti₅O₁₁) for energy and environmental issues are summarized. Layered alkali titanates of various structural types and compositions are regarded as a class of nanostructured materials based on titanium oxide frameworks. If compared with commonly known titanium dioxides (anatase and rutile), materials design based on layered alkali titanates is quite versatile due to the unique structure (nanosheet) and morphological characters (anisotropic particle shape). Recent development of various synthetic methods (solid-state reaction, flux method, and hydrothermal reaction) for controlling the particle shape and size of layered alkali titanates are discussed. The ion exchange ability of layered alkali titanate is used for the collection of metal ions from water as well as a way of their functionalization. These possible materials design made layered alkali titanates promising for energy (including catalysis, photocatalysts, and battery) and environmental (metal ion concentration from aqueous environments) applications.

关键词： layered alkali titanates photocatalysis hydrogen evdution metal ions collection

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碱硅酸反应与碱碳酸盐反应

唐明述

《中国工程科学》 2000年第2卷第1期页码 34-40

摘要：

碱集料反应（AAR）可分为两类，即碱硅酸反应（ASR）与碱碳酸盐反应（ACR）。二者的共同点是与碱发生的化学反应可导致混凝土中集料的体积增大，从而可能使混凝土甚至整个建筑物或构筑物发生膨胀开裂。文章着重从膨胀过程和机理以及岩石的结构特征探讨二者的特性与差异。ASR类型岩石具有碱活性的前提条件是较低的二氧化硅结晶完整度。只有隐晶质、微晶质、玻璃质或发生过应变的二氧化硅才会具有较高的化学活性，导致混凝土破坏。通过系统研究证实，对碱碳酸盐反应，虽然结晶的完整程度以及白云石（CaCO₃·MgCO₃）分子式中Ca/Mg比也将影响其与碱反应的速率，但起决定作用的是白云石晶体的尺寸及其在岩石中的分布状态和被基质包围的紧密程度。从微观结构得出的这些特征将有助于加深对碱集料反应膨胀机理的认识。文中还介绍了形成活性白云石的地质环境和碱硅酸反应与碱碳酸盐反应的区分方法。

关键词：碱集料硅酸碳酸盐混凝土开裂机理

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The development of ultralightweight expanded perlite-based thermal insulation panel using alkali activator

Damla Nur ÇELİK; Gökhan DURMUŞ

《结构与土木工程前沿（英文）》 2022年第16卷第11期页码 1486-1499 doi: 10.1007/s11709-022-0881-6

摘要： The International Energy Agency (IEA) states that global energy consumption will increase by 53% by 2030. Turkey has 70% of the world’s perlite reserves, and in order to reduce energy consumption a thermal insulation panel was developed in Turkey using different particle sizes of expanded perlite (EP). In this study, 0–1.18 mm (powder) and 0–3 mm (granular) EP particle sizes were selected, since they have the lowest thermal conductivity coefficients among all the particle sizes. In addition, an alkali activator solution was used as a binder in the mixtures. The alkaline activator solution was obtained by mixing sodium hydroxide solution (6, 8, 10, and 12 mol·L⁻¹) and sodium silicate (Module 3) at the different ratios of Na₂SiO₃ to NaOH of 1, 1.5, 2, and 2.5. This study aimed to experimentally determine the optimum binder and distribution ratio of EP, with the lowest coefficient of thermal conductivity and the lowest density. The lowest thermal conductivity and the lowest density were determined as 0.04919 W·m⁻¹·K⁻¹ and 133.267 kg/m³, respectively, in the sample prepared with 83.33% powder-size EP, 6 mol·L⁻¹ sodium hydroxide solution, and ratio of Na₂SiO₃ to NaOH of 1.5. The density, thermal conductivity, and compressive strength of the sample showed the same trends of behavior when the Na₂SiO₃ to NaOH ratio was increased. In addition, the highest compressive strength was measured in 12 mol·L⁻¹ NaOH concentration regardless of particle size. In conclusion, the study predicts that the EP-based thermal insulation panel can be used as an insulation material in the construction industry according to the TS825 Thermal Insulation Standard.

关键词： expanded perlite alkali activator thermal insulation panel thermal conductivity

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Utilization of alkali-activated copper slag as binder in concrete

《结构与土木工程前沿（英文）》 2021年第15卷第3期页码 773-780 doi: 10.1007/s11709-021-0722-z

摘要： This study was focused on developing concrete using alkali-activated copper slag (AACS) as a binder. The properties of alkali-activated copper slag concrete (AACSC) were compared with portland cement concrete (PCC). Different AACSC mixes were prepared with varying Na₂O dosage (6% and 8% of the binder by weight) and curing methods. Hydration products in AACSC were retrieved using Fourier-transform infrared spectroscopy (FTIR) and X-ray powder diffraction (XRD) techniques. The test results indicate that the workability of AACSC was lesser than that of PCC. The AACSC mix with 6% Na₂O dosage has exhibited similar mechanical properties as that of PCC. The mechanical properties of AACSC were higher than PCC when 8% of Na₂O dosage was used. Heat curing was effective to upgrade the strength properties of AACSC at an early age of curing, but at a later age mechanical properties of ambient cured and heat-cured AACSC were comparable. The hydration products of AACSC were not identified in XRD patterns, whereas, in FTIR spectra of AACSC some alkali-activated reaction products were reflected. The AACSC mixes were found to be more sustainable than PCC. It has been concluded that AACSC can be produced similarly to that of PCC and ambient curing is sufficient.

关键词： binder concrete mechanical properties mineralogy workability

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Enhanced activation of peroxymonosulfate by CNT-TiO

Xuemin Hao, Guanlong Wang, Shuo Chen, Hongtao Yu, Xie Quan

《环境科学与工程前沿（英文）》 2019年第13卷第5期 doi: 10.1007/s11783-019-1161-0

摘要： CNT-TiO2 composite is used to activate PMS under UV-light assistance. Superior performance is due to the enhanced electron-transfer ability of CNT. SO4•−, •OH and 1O2 play key roles in the degradation of organic pollutants. In this work, a UV-light assisted peroxymonosulfate (PMS) activation system was constructed with the composite catalyst of multi-walled carbon nanotubes (CNT) - titanium dioxide (TiO2). Under the UV light irradiation, the photoinduced electrons generated from TiO2 could be continuously transferred to CNT for the activation of PMS to improve the catalytic performance of organic pollutant degradation. Meanwhile, the separation of photoinduced electron-hole pairs could enhance the photocatalysis efficiency. The electron spin resonance spectroscopy (EPR) and quenching experiments confirmed the generation of sulfate radical (SO4•−), hydroxyl radical (•OH) and singlet oxygen (1O2) in the UV/PMS/20%CNT-TiO2 system. Almost 100% phenol degradation was observed within 20 min UV-light irradiation. The kinetic reaction rate constant of the UV/PMS/20%CNT-TiO2 system (0.18 min−1) was 23.7 times higher than that of the PMS/Co3O4 system (0.0076 min−1). This higher catalytic performance was ascribed to the introduction of photoinduced electrons, which could enhance the activation of PMS by the transfer of electrons in the UV/PMS/CNT-TiO2 system.

关键词： Peroxymonosulfate activation Carbon nanotubes TiO₂ Water treatment

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Hierarchical porous carbon derived from one-step self-activation of zinc gluconate for symmetric supercapacitors

《化学科学与工程前沿（英文）》 2023年第17卷第4期页码 387-394 doi: 10.1007/s11705-022-2250-3

摘要： Porous carbons with high specific area surfaces are promising electrode materials for supercapacitors. However, their production usually involves complex, time-consuming, and corrosive processes. Hence, a straightforward and effective strategy is presented for producing highly porous carbons via a self-activation procedure utilizing zinc gluconate as the precursor. The volatile nature of zinc at high temperatures gives the carbons a large specific surface area and an abundance of mesopores, which avoids the use of additional activators and templates. Consequently, the obtained porous carbon electrode delivers a satisfactory specific capacitance and outstanding cycling durability of 90.9% after 50000 cycles at 10 A∙g^–1. The symmetric supercapacitors assembled by the optimal electrodes exhibit an acceptable rate capability and a distinguished cycling stability in both aqueous and ionic liquid electrolytes. Accordingly, capacitance retention rates of 77.8% and 85.7% are achieved after 50000 cycles in aqueous alkaline electrolyte and 10000 cycles in ionic liquid electrolyte. Moreover, the symmetric supercapacitors deliver high energy/power densities of 49.8 W∙h∙kg^–1/2477.8 W∙kg^–1 in the Et₄NBF₄ electrolyte, outperforming the majority of previously reported porous carbon-based symmetric supercapacitors in ionic liquid electrolytes.

关键词： self-activation zinc organic salts abundant mesopores symmetric supercapacitor liquid electrolyte

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Enhanced performance of oxygen vacancies on CO adsorption and activation over different phases of ZrO

《能源前沿（英文）》 2023年第17卷第4期页码 545-554 doi: 10.1007/s11708-023-0867-7

摘要： The effect of oxygen vacancies on the adsorption and activation of CO₂ on the surface of different phases of ZrO₂ is investigated by density functional theory (DFT) calculations. The calculations show that the oxygen vacancies contribute greatly to both the adsorption and activation of CO₂. The adsorption energy of CO₂ on the c-ZrO₂, t-ZrO₂ and, m-ZrO₂ surfaces is enhanced to 5, 4, and 3 folds with the help of oxygen vacancies, respectively. Moreover, the energy barrier of CO₂ dissociation on the defective surfaces of c-ZrO₂, t-ZrO₂, and m-ZrO₂ is reduced to 1/2, 1/4, and 1/5 of the perfect surface with the assistance of oxygen vacancies. Furthermore, the activation of CO₂ on the ZrO₂ surface where oxygen vacancies are present, and changes from an endothermic reaction to an exothermic reaction. This finding demonstrates that the presence of oxygen vacancies promotes the activation of CO₂ both kinetically and thermodynamically. These results could provide guidance for the high-efficient utilization of CO₂ at an atomic scale.

关键词： CO₂ activation oxygen vacancies ZrO₂ different phases

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碱激发矿渣混凝土的水化特性及微观结构研究进展 Review

傅强,卜梦鑫, 张兆瑞, 许文瑞, 元强, 牛荻涛

《工程（英文）》 2023年第20卷第1期页码 162-179 doi: 10.1016/j.eng.2021.07.026

摘要：

碱激发矿渣混凝土（alkali-activated slag concrete, AASC）是一种新型的绿色建材，与普通硅酸盐混凝土相比，

关键词：碱激发矿渣混凝土水化特性孔结构界面过渡区微观结构

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A density functional theory study of methane activation on MgO supported NiM cluster: role of M on C–Hactivation

《化学科学与工程前沿（英文）》 2022年第16卷第10期页码 1485-1492 doi: 10.1007/s11705-022-2169-8

摘要： Methane activation is a pivotal step in the application of natural gas converting into high-value added chemicals via methane steam/dry reforming reactions. Ni element was found to be the most widely used catalyst. In present work, methane activation on MgO supported Ni–M (M = Fe, Co, Cu, Pd, Pt) cluster was explored through detailed density functional theory calculations, compared to pure Ni cluster. CH₄ adsorption on Cu promoted Ni cluster requires overcoming an energy of 0.07 eV, indicating that it is slightly endothermic and unfavored to occur, while the adsorption energies of other promoters M (M = Fe, Co, Pd and Pt) are all higher than that of pure Ni cluster. The role of M on the first C–H bond cleavage of CH₄ was investigated. Doping elements of the same period in Ni cluster, such as Fe, Co and Cu, for C–H bond activation follows the trend of the decrease of metal atom radius. As a result, Ni–Fe shows the best ability for C–H bond cleavage. In addition, doping the elements of the same family, like Pd and Pt, for CH₄ activation is according to the increase of metal atom radius. Consequently, C–H bond activation demands a lower energy barrier on Ni–Pt cluster. To illustrate the adsorptive dissociation behaviors of CH₄ at different Ni–M clusters, the Mulliken atomic charge was analyzed. In general, the electron gain of CH₄ binding at different Ni–M clusters follows the sequence of Ni–Cu (–0.02 e) < Ni (–0.04 e) < Ni–Pd (–0.08 e) < Ni–Pt (–0.09 e) < Ni–Co (–0.10 e) < Ni–Fe (–0.12 e), and the binding strength between catalysts and CH ₄ raises with the CH₄ electron gain increasing. This work provides insights into understanding the role of promoter metal M on thermal-catalytic activation of CH₄ over Ni/MgO catalysts, and is useful to interpret the reaction at an atomic scale.

关键词： CH₄ dissociation Ni–M C–H bond activation charge transfer

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Optimal dynamic emergency reserve activation using spinning, hydro and demand-side reserves

S. Surender REDDY,P. R. BIJWE,A. R. ABHYANKAR

《能源前沿（英文）》 2016年第10卷第4期页码 409-423 doi: 10.1007/s11708-016-0431-9

摘要： This paper proposes an optimal dynamic reserve activation plan after the occurrence of an emergency situation (generator/transmission line outage, load increase or both). An optimal plan is developed to handle the emergency, using the coordinated action of fast and slow reserves, for secure operation with minimum overall cost. It considers the reserves supplied by the conventional thermal generators (spinning reserves), hydro power units and load demands (demand-side reserves). The optimal backing down of costly/fast reserves and bringing up of slow reserves in each sub-interval in an integrated manner is proposed. The proposed reserve activation approaches are solved using the genetic algorithm, and some of the simulation results are also compared using the Matlab optimization toolbox and the general algebraic modeling system (GAMS) software. The simulation studies are performed on the IEEE 30, 57 and 300 bus test systems. These results demonstrate the advantage of the proposed integrated/dynamic reserve activation plan over the conventional/sequential approach.

关键词： demand-side reserves dynamic reserve activation approach hydro power units post contingency sequential reserve activation approach spinning reserves

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The Decarbonization of Construction—How Can Alkali-Activated Materials Contribute?

John L. Provis,Susan A. Bernal,Zuhua Zhang,

《工程（英文）》 doi: 10.1016/j.eng.2023.09.014

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Tumor-derived exosomes induce initial activation by exosomal CD19 antigen but impair the function of

《医学前沿（英文）》 doi: 10.1007/s11684-023-1010-1

摘要： Tumor-derived exosomes induce initial activation by exosomal CD19 antigen but impair the function of CD19-specific CAR T-cells via TGF-β signaling

关键词： exosomes induce activation impair function CD19 exosomal CD19 antigen

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井下裂缝连通技术在安棚碱矿的应用

齐铁新,刘建中,秦桂林,董峰

《中国工程科学》 2006年第8卷第7期页码 63-67

摘要：

介绍了在桐柏安棚碱矿，用微地震监测结合水准测量监测与注水井连通的原生裂隙带的理论、技术、方法和监测结果，并据此部署开采井位，把采液井打在与注水井连通的裂隙带上，实现了2条注、采井1 000m米井下裂隙带连通,使安棚碱矿可以连续注水、采出碱液，从而获得较高的生产水平和经济效益。

关键词：安棚碱矿湿法采碱井底裂缝连通水准测量微地震监测

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Modeling of alkali-silica reaction in concrete: a review

J.W. PAN, Y.T. FENG, J.T. WANG, Q.C. SUN, C.H. ZHANG, D.R.J. OWEN

《结构与土木工程前沿（英文）》 2012年第6卷第1期页码 1-18 doi: 10.1007/s11709-012-0141-2

摘要： This paper presents a comprehensive review of modeling of alkali-silica reaction (ASR) in concrete. Such modeling is essential for investigating the chemical expansion mechanism and the subsequent influence on the mechanical aspects of the material. The concept of ASR and the mechanism of expansion are first outlined, and the state-of-the-art of modeling for ASR, the focus of the paper, is then presented in detail. The modeling includes theoretical approaches, meso- and macroscopic models for ASR analysis. The theoretical approaches dealt with the chemical reaction mechanism and were used for predicting pessimum size of aggregate. Mesoscopic models have attempted to explain the mechanism of mechanical deterioration of ASR-affected concrete at material scale. The macroscopic models, chemo-mechanical coupling models, have been generally developed by combining the chemical reaction kinetics with linear or nonlinear mechanical constitutive, and were applied to reproduce and predict the long-term behavior of structures suffering from ASR. Finally, a conclusion and discussion of the modeling are given.

关键词： alkali-silica reaction (ASR) modeling concrete mesoscopic macroscopic