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Superior strength-plasticity synergy in a heterogeneous lamellar Ti_(2)AlC/TiAl composite with unique interfacial microstructure

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Journal of Materials Science & Technology 2023年第28期159卷 21-32页

作者： Pei Liu Bo Hou aiqin wang Jingpei Xie Zhenbo wang Feng Ye College of Materials Science and Engineering Henan University of Science and TechnologyLuoyang 471023China Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology Luoyang 471023China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

Improving the plasticity of TiAl alloys at room temperature has been a longstanding challenge for the de-velopment of next-generation aerospace *** adopting the nacre-like architecture design strategy,we have obtained a novel heterogeneous lamellar Ti_(2)AlC/TiAl composite with superior strength-plasticity synergy,i.e.,compressive strength of∼2065 MPa and fracture strain of∼27%.A combination of micropil-lar compression and large-scale atomistic simulation has revealed that the superior strength-plasticity synergy is attributed to the collaboration of Ti_(2)AlC reinforcement,lamellar architecture and heteroge-neous *** specifically,multiple deformation modes in Ti_(2)AlC,i.e.,basal-plane dislocations,atomic-scale ripples and kink bands,could be activated during the compression,thus promoting the plas-tic deformation capability of ***,the lamellar architecture could not only induce sig-nificant stress redistribution and crack deflection between Ti_(2)AlC and TiAl,but also generate high-density SFs and DTs interactions in TiAl,leading to an improved strength and strain hardening *** addi-tion,profuse unique Ti_(2)AlC(1¯10¯3)/TiAl(111)interfaces in the composite could dramatically contribute to the strength and plasticity due to the interface-mediated dislocation nucleation and obstruction *** findings offer a promising paradigm for tailoring microstructure of TiAl matrix composites with extraordinary strength and plasticity at ambient temperature.

关键词： Ti_(2)AlC/TiAl composite Heterogeneous lamellar microstructure Micropillar compression Interface-mediated deformation Strength-plasticity synergy

Removal of antibiotics from aqueous solution by using porous adsorbent templated from eco-friendly Pickering aqueous foams

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Journal of Environmental Sciences 2021年第4期33卷 352-362页

作者： Hui Yu Yongfeng Zhu Aiping Hui Fangfang Yang aiqin wang Key Laboratory of Clay Mineral Applied Research of Gansu Province Center of Eco-material and Green ChemistryLanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The aqueous foam template without any solvent and only using the particles stabilizer has attracted much attention for preparation of the porous ***,a novel porous adsorbent was fabricated via thermal-initiated polymerization of Pickering aqueous foams,which was stabilized by the natural sepiolite(Sep)and pine pollen,and utilized for the removal of antibiotic from aqueous *** stabilizing mechanism of Pickering aqueous foam of that the Sep was modified with the leaching substance from pine pollen and arranged orderly around the bubble to form a dense"shell"structure was *** adsorbents possessed the hierarchical porous structure and excellent adsorption performance for antibiotic of chlorotetracycline hydrochloride(CTC)and tetracycline hydrochloride(TC).The equilibrium adsorption capacities of CTC and TC were achieved with 465.59 and 330.59 mg/g within 60 min at 25℃,*** adsorption process obeyed Langmuir model and pseudo-second-order adsorption kinetic *** work provided eco-friendly approach for fabricate porous adsorbents for wastewater treatment.

关键词： Porous adsorbent Adsorption Antibiotic Pickering aqueous foams Pollen Sepiolite

Fabrication porous adsorbents templated from aqueous foams using astragalus membranaceus and attapulgite as stabilizer for efficient removal of cationic dyes

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Journal of Environmental Sciences 2023年第5期127卷 855-865页

作者： Fangzhi Duan Yongfeng Zhu Yushen Lu Jiang Xu aiqin wang Key Laboratory of Clay Mineral Applied Research of Gansu Province Center of Eco-material and Green ChemistryLanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The water-based foam stabilized by the natural surfactant applied in the fabrication of porous materials has attracted extensive attention,as the advantages of cleanness,convenience and low ***,the development of a green preparation method has became themain research focus and *** thiswork,a green liquid foamwith high stability was prepared by synergistic stabilization of natural plant astragalus membranaceus(AMS)and attapulgite(APT),and then a novel porous material with sufficient hierarchical pore structure was templated from the foam via a simple free radical polymerization of acrylamide(AM).The characterization results revealed that the amphiphilic molecules from AMS adsorbed onto thewater-air interface and formed a protective shell to prevent the bubble breakup,and APT gathered in the plateau border and formed a three-dimensional network structure,which greatly slowed down the drainage *** porous material polyacrylamide/astragalus membranaceus/attapulgite(PAM/AMS/APT)showed the excellent adsorption performance for cationic dyes of Methyl Violet(MV)and Methylene Blue(MB)in water,and the maximum adsorption capacity could reach to 709.13 and 703.30 mg/g,***,the polymer material enabled to regenerate and cycle via a convenient calcination process,and the adsorption capacitywas still higher than 200 mg/g after five *** short,this research provided a new idea for the green preparation of porous materials and the treatment of water pollution.

关键词： Astragalus membranaceus Pickering foam Porous material Adsorption Biochar

Synthesis, Characterization, and Catalytic Application of Highly Ordered Mesoporous Alumina-Carbon Nanocomposites

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Nano Research 2011年第1期4卷 50-60页

作者： Jinming Xu aiqin wang Xiaodong wang Dangsheng Su Tao Zhang State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences 457 Zhongshan Road Dalian 116023 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Fritz-Haber Institute of the Max Planck Society Berlin D-14195 Germany

Highly ordered mesoporous carbon-alumina nanocomposites （OMCA） have been synthesized for the first time by a multi-component co-assembly method followed by pyrolysis at high temperatures. In this synthesis, resol phenol-formaldehyde resin （PF resin） and alumina sol were respectively used as the carbon and alumina precursors and triblock copolymer Pluronic F127 as the template. N2-adsorption measurements, X-ray diffraction, and transmission electron microscopy revealed that, with an increase of the alumina content in the nanocomposite from 11 to 48 wt.%, the pore size increased from 2.9 to 5.0 nm while the ordered mesoporous structure was retained. Further increasing the alumina content to 53 wt.% resulted in wormhole-like structures, although the pore size distribution was still narrow. The nanocomposite walls are composed of continuous carbon and amorphous alumina, which allows the ordered mesostructure to be well preserved even after the removal of alumina by HF etching or the removal of carbon by calcination in air. The OMCA nanocomposites exhibited good thermostability below 1000℃; at higher temperatures the ordered mesostructure partially collapsed, associated with a phase transformation from amorphous alumina into γ-Al2O3. OMCA-supported Pt catalysts exhibited excellent performance in the one-pot transformation of cellulose into hexitols thanks to the unique surface properties of the nanocomposite.

关键词： Nanocomposite mesoporous alumina carbon cellulose

Modification and aging precipitation behavior of hypereutectic AI-21wt.%Si alloy treated by P+Ce combination

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China Foundry 2014年第6期11卷 516-521页

作者： Liu Pei wang aiqin Xie Jingpei Materials Science and Engineering School of Henan University of Science and Technology

In the present study, the tested hypereutectic Al-21wt.%Si alloys were prepared by modifying the melt using different proportions of P and Ce, and then applying T6 heat treatment. The modification effects and mechanism of P＋Ce complex modifier on the Si phase of hypereutectic Al-21wt.%Si alloy were studied, and the aging precipitation behavior after modification was characterized by means of tensile strength measurement, OM, SEM and TEM analysis. The results show that the massive primary silicon phase particles are significantly refined after modification, while the needle-like eutectic silicon crystals become fibrous and short. It was found that the mechanism of phosphorus modification on the primary silicon can be attributed to heterogeneous nucleation of AlP, while the modification mechanism of Ce can be explained by adsorbing-twinning theory. In the aged microstructure of the modified hypereutectic Al-21wt.%Si alloy, there existed some strengthening phases such as AI4Cu9, Al2Cu, AlCu3, and Al57Mn12. The P＋Ce complex modifier not only affected the size of primary silicon and eutectic silicon, but also the aging behavior of alloys under the heat treatment process. When Al-21wt.%Si alloy was modified using 0.08%wt.P ＋ 0.6wt.% Ce, the aging precipitates were dispersed uniformly in the alloy, and its mechanical properties at room and elevated temperatures are optimized （Rm = 287.6 MPa at RT, Rm = 210 MPa at 300 ℃）.

关键词： combination modification hypereutectic Al-21wt.%Si alloy microstructure aging precipitation

Single-atom catalyst: a rising star for green synthesis of fine chemicals

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National Science Review 2018年第5期5卷 653-672页

作者： Leilei Zhang Yujing Ren Wengang Liu aiqin wang Tao Zhang State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of Sciences University of Chinese Academy of Sciences

The green synthesis of fine chemicals calls for a new generation of efficient and robust catalysts. Single-atom catalysts(SACs), in which all metal species are atomically dispersed on a solid support, and which often consist of well-defined mononuclear active sites, are expected to bridge homogeneous and heterogeneous catalysts for liquid-phase organic transformations. This review summarizes major advances in the SAC-catalysed green synthesis of fine chemicals in the past several years, with a focus on the catalytic activity, selectivity and reusability of SACs in various organic reactions. The relationship between catalytic performance and the active site structure is discussed in terms of the valence state, coordination environment and anchoring chemistry of single atoms to the support, in an effort to guide the rational design of SACs in this special area, which has traditionally been dominated by homogeneous ***, the challenges remaining in this research area are discussed and possible future research directions are proposed.

关键词： single-atom catalysts fine chemicals green synthesis structure–reactivity relationship heterogeneous catalysis

Inhibiting effect of tungstic compounds on glucose hydrogenation over Ru/C catalyst

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Journal of Energy Chemistry 2015年第1期24卷 9-14页

作者： Junying Zhang Baolin Hou Xuefei wang Zhenlei Li aiqin wang Tao Zhang State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences College of Science Beijing University of Chemical Technology

The effect of acid component including various conventional acids and tungstic compounds on glucose hydrogenation over a series of binary catalyst system containing Ru/C catalyst was investigated. The results showed that HC1, H2SO4, H3BO3, H3PO4, and HNO3 had negligible effect, while all the tungstic compounds imposed inhibiting effects on the hydrogenation of glucose over Ru/C catalyst, and the suppressing effect followed the order of H2WO4〉HPW〉WO3〉AMT〉HSiW. This order is the same as the order of ethylene glycol （EG） yields in the one-pot conversion of glucose to EG, suggesting the important role of competition between glucose hydrogenation and retro-aldol condensation in controlling the selectivity of EG.

关键词： glucose hydrogenation binary catalyst system suppressing effect retro-aldol condensation ethylene glycol tungstic compounds Ru/C cata-lyst

From illite/smectite clay to mesoporous silicate adsorbent for efficient removal of chlortetracycline from water

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Journal of Environmental Sciences 2017年第1期29卷 31-43页

作者： Wenbo wang Guangyan Tian Li Zong Yanmin Zhou Yuru Kang Qin wang aiqin wang Center of Eco-materials and Green Chemistry Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China University of the Chinese Academy of Sciences Beijing 100049China Key Laboratory of Clay Mineral Applied Research of Gansu Province Lanzhou 730000China College of Animal Science and Technology Nanjing Agricultural UniversityNanjing 210095China

A series of mesoporous silicate adsorbents with superior adsorption performance for hazardous chlortetracycline（CTC） were sucessfully prepared via a facile one-pot hydrothermal reaction using low-cost illite/smectite（IS） clay,sodium silicate and magnesium sulfate as the starting *** this process,IS clay was ＂teared up＂ and then ＂rebuilt＂ as new porous silicate adsorbent with high specific surface area of 363.52 m^2/g（about 8.7 folds higher than that of IS clay） and very negative Zeta potential（- 34.5 mV）.The inert Si- O- Si（Mg,Al） bonds in crystal framework of IS were broken to form Si（Al）- O^- groups with good adsorption activity,which greatly increased the adsorption sites served for holding much CTC *** evaluation on adsorption properties reveals the optimal silicate adsorbent can adsorb 408.81 mg/g of CTC（only 159.7 mg/g for raw IS clay） and remove 99.3%（only 46.5%for raw IS clay） of CTC from 100 mg/L initial solution（pH 3.51;adsorption temperature 30℃;adsorbent dosage,3 g/L）.The adsorption behaviors of CTC onto the adsorbent follows the Langmuir isotherm model,Temkin equation and pseudo second-order kinetic *** mesopore adsorption,electrostatic attraction and chemical association mainly contribute to the enhanced adsorption *** a whole,the high-efficient silicate adsorbent could be candidates to remove CTC from the wastewater with high amounts of CTC.

关键词： Illite/smectite clay Hybrid silicate adsorbent Chlortetracycline Removal

Contact Resistance and Arc Erosion of Tungsten-copper Contacts in Direct Currents

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Journal of Wuhan University of Technology(Materials Science) 2017年第4期32卷 816-822页

作者：马窦琴 XIE Jingpei LI Jiwen wang aiqin wang Wenyan School of Materials Science and Engineering Henan University of Science and Technology Luoyang 471023 China Non-ferrous Metal Generic Technology Collaborative Innovation Center of Henan Province Luoyang 471023 China

The arc erosion under medium direct currents in the argon flow was tested on tungsten-copper（W-Cu） contacts which were processed by hot extrusion and heat treatment. The scanning electron microscopy（SEM） and transmission electron microscopy（TEM） were used to study the microstructure of the W-Cu powders and compacts. The contact resistance, arcing energy, and arcing time were continuously measured by JF04C contact materials test system. Changes in tungsten-copper contact surface were observed by SEM. The test results showed that the arcing time and arcing energy all increase with current and voltage, but the changes of average contact resistance are more complicated. For a short arcing time, the average contact resistance decreases with increasing current due to the vaporization of Cu. However, for a longer arcing time, it slightly increases due to the formation of high resistant films, compound copper tungsten. The formation of compound copper tungsten was confirmed by the increased Rc kept in the range from 1.1 to 1.6 mΩ. The compound copper tungsten is first exposed with a tungsten and copper-rich surface, and then totally exposed due to evaporation of copper from the surface. At last a stabilized surface is created and the crystals decrease from 8 μm to 2 μm caused by the arc erosion.

关键词： Tungsten-copper contacts arc erosion contact resistance surface analysis