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Microstructure evolution,mechanical properties and creep mechanisms of Mg-12Gd-1MM-0.6Zr(wt%)magnesium alloy

Journal of Rare Earths 2021年第5期39卷 600-608页

作者： Bibo Li Kui Zhang Guoliang Shi Kaikun Wang Yongjun Li Xinggang Li Minglong Ma Jiawei Yuan State Key Laboratory of Nonferrous Metals and Process GRINM Group Co.Ltd.(GRINM)Beijing 100088China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China

In this research,the microstructure evolution,mechanical properties,and creep mechanisms of Mg-12 Gd-1 MM-0.6 Zr(wt%)alloy under different conditions were systematically studied using scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),and tensile creep *** the microstructure of the as-cast sample,the average grain size is about 42μm,and the eutectic compounds were determined to be Mg_(5)(Gd_(0.8)MM_(0.2)).During homogenization,these eutectic compounds gradually dissolve,and Mg_(12)MM particles are *** hot extrusion,complete dynamic recrystallization(DRX)occurs,resulting in equiaxial grains with an average grain size of about 12μm and the formation of streamlines consisting of Mg_(12)MM particles along the extrusion direction(ED).After T5 treatment(225℃for 7 h),a large number ofβ'(Mg_(7)Gd)phases are precipitated on the{11-20}αhabit plane and are interconnected,forming an interlaced network *** ultimate tensile strength(R_(m)=405 MPa)and yield strength(R_(P0.2)=288 MPa)of the T5 sample are significantly higher than those of the as-extruded sample(R_(m)=289 MPa,R_(P0.2)=185 MPa),but the elongation(A=4%)was remarkably lower than that of the as-extruded sample(A=18%).When crept at225℃under 100 MPa,the steady-state creep rates of the as-cast,as-extruded,and T5 samples are1.59×10^(-8),1.08×10^(-8),and 1.40×10^(-8)s^(-1),respectively,and their total strains within 100 h are respectively breaking,0.81%,and 0.92%,indicating that the as-extruded alloy exhibits the best creep *** analysis reveals that,during the creep process of the T5 sample,theβ'particles coarsen and the precipitate-free zones(PFZs)widen,which increase the steady-state creep rate and the total strain within 100 h as compared with the as-extruded sample.

关键词： Magnesium alloy Extrusion Creep mechanism Microstructure evolution Precipitation Rare earths

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Performance Evaluation on Chemical Looping Oxidative Dehydrogenation of Ethane Via Fe2O3@SiO2 Oxygen Carriers

SSRN

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SSRN 2024年

作者： Wang, Zhichao Liang, Wei Li, Meixin Yang, Xiantan Sun, Zhongshun Yang, Bolun Sun, Bing Wu, Zhiqiang Shaanxi Key Laboratory of Energy Chemical Process Intensification School of Chemical Engineering and Technology Xi'an Jiaotong University Shaanxi Xi’an710049 China State Key Laboratory of Chemical Safety SINOPEC Research Institute of Safety Engineering Co. Ltd. Qingdao266071 China

Precisely controlling the matching between lattice oxygen migration rates and surface reaction kinetics is a critical challenge in designing oxygen carriers for the partial oxidation of lower alkanes. In this study, the introduction of SiO2 encapsulation enabled the nanostructuring of the oxygen carrier, allowing for the successful tuning of the lattice oxygen reactivity in the Fe2O3 redox oxygen carrier. This, in turn, achieved efficient ethylene production in the chemical looping oxidative dehydrogenation (CL-ODH) of ethane. The incorporation of SiO2 effectively reduced the grain size of the Fe2O3 oxygen carrier, providing more active sites and enabling efficient and well-regulated lattice oxygen migration. As a result, the Fe2O3 oxygen carrier exhibited an optimal match between lattice oxygen migration rates and surface reaction kinetics, achieving a 41.0% ethane conversion and 60.1% ethylene selectivity under the conditions of processing 120 mL of ethane at 700 °C in a single cycle. This work not only provides a highly active CL-ODH oxygen carrier but also offers an effective approach for future large-scale industrial production of chemical looping oxidative dehydrogenation of ethane. © 2024, The Authors. All rights reserved.

关键词： Surface reactions

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Deterministic Synthesis of Pd Nanocrystals Enclosed by High-Index Facets and Their Enhanced Activity toward Formic Acid Oxidation

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Precision Chemistry 2023年第6期1卷 372-381页

作者： Maochang Liu Siyu Zhou Sang-Il Choi Younan Xia The Wallace H.Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory UniversityAtlantaGeorgia 30332United States International Research Center for Renewable Energy State Key Laboratory of Multiphase FlowXi’an Jiaotong UniversityXi’anShanxi 710049P.R.China School of Chemical and Biomolecular Engineering Georgia Institute of TechnologyAtlantaGeorgia 30332United States School of Chemistry and Biochemistry and School of Chemical and Biomolecular Engineering Georgia Institute of TechnologyAtlantaGeorgia 30332United States

Noble-metal nanocrystals enclosed by high-index facets are of growing interest due to their enhanced catalytic performance in a variety of ***,we report the deterministic synthesis of Pd nanocrystals encased by high-index facets by controlling the rate of deposition(V_(deposition))relative to that of surface diffusion(V_(diffusion)).For octahedral seeds with truncated corners,a reduction rate(and thus deposition rate)faster than that of surface diffusion(i.e.,V_(deposition)/V_(diffusion)>1)led to the formation of concave trisoctahedra(TOH)with high-index *** the reduction was slowed down,in contrast,surface diffusion dominated the growth *** the case of V_(deposition)/V_(diffusion)≈1,truncated octahedra with enlarged sizes were *** the reduction rate was between these two extremes,we obtained concave tetrahexahedra(THH)without or with *** growth patterns were also observed for the cuboctahedral *** the Pd octahedra,concave TOH,and concave THH were tested for electrocatalyzing the formic acid oxidation(FAO)reaction,those with high-index facets were advantageous over the conventional Pd octahedra enclosed by{111}*** work not only contributes to the understanding of surface diffusion and its role in nanocrystal growth but also offers a general protocol for the synthesis of nanocrystals enclosed by high-index facets.

关键词： palladium surface diffusion high-index facet unconventional morphology kinetic control

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Microstructure and corrosion resistance of bone-implanted Mg-Zn-Ca-Sr alloy under different cooling methods

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Rare Metals 2021年第3期40卷 643-650页

作者： He-Ning Liu Kui Zhang Xing-Gang Li Yong-Jun Li Ming-Long Ma Guo-Liang Shi Jia-Wei Yuan Kai-Kun Wang State Key Laboratory of Nonferrous Metals and Process GRINM Group Co.Ltd.Beijing 100088China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China

The cooling gradient of Mg-3 Zn-1 Ca-0.5 Sr alloy in cast ingots under different cooling methods(air cooling,warm-water cooling and ice-water-mixture cooling) was examined and the effect of cooling rate on the structure and corrosion properties was *** microstructure of the alloy was composed of α-Mg,Ca_(2) Mg_(6) Zn_(3) and Mg_(17)Sr_(2) *** the solidification cooling rate increased,the grain was refined,Zn and Sr were less segregated,the distributions of Zn and Sr were more uniform,and corrosion rate was found to first increase and then decrease;this contradicts the findings of recent *** cooling rate increasing,the number of corroded microcouples comprising second phase and α-Mg *** α-Mg participates in corrosion,leading to a layered and deep corrosion pit and an increased corrosion ***,as the microstructure became sufficiently dense,the corroded structure protected the deep α-Mg from participating in corrosion,thus reducing the corrosion rate.

关键词： Corrosion Mg-Zn-Ca-Sr Morphology Cooling methods

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Reactive nano-essential oils for sustained release of essential oils and application to wallpaper

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Chinese Chemical Letters 2022年第1期33卷 320-323页

作者： Qiulian Hao Huan Peng Ruichen Zhao Jianze Wang Zhiguo Lu Jingwen Wang Jie Shen Yunwei Niu Zuobing Xiao Guiying Liu Jifu Hao Xin Zhang School of Pharmaceutical Science Shandong First Medical University&Shandong Academy of Medical SciencesTaian 271016China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Department of Pediatrics Capital Medical University Affiliated Beijing Anzhen HospitalBeijing 100029China School of Chemical Engineering University of Chinese Academy of SciencesBeijing 100049China Shanghai Research Institute of Fragrance and Flavor Industry Shanghai 200232China School of Perfume and Aroma Technology Shanghai Institute of TechnologyShanghai 200233China

Essential oils are a volatile and aromatic substance with a variety of active biological ***,the excessive volatility and inconvenience of the use of essential oils limit their *** this study,we developed a reactive mesoporous silica nanoparticle(rMSNs)based on cyanuric chloride modification for essential oil encapsulation and commodity *** large pore volume and specific surface area of rMSNs facilitate the nanoparticles adhering to a large amount of essential oil and achieve the sustained release of essential oil,thus prolonging the fragrance retention time of essential *** reactive nanoessential oils can form covalent bonds with the wallpaper,thereby remarkably improving the adhesion of the reactive nano-essential oils on the wallpaper and preventing the reactive nano-essential oil from deadhering from the *** active nano essential oil simultaneously overcomes the intense volatility of the essential oil and inconvenience in use,has a simple preparation process and low cost,and has great application potential.

关键词： Reactive nano-essential oils Reactive mesoporous silica nanoparticles Slow-release of essential oils Application to wallpaper Covalent bonds

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Photothermal assisted CO2 photoreduction over hollow urchin-like structured TiO2@SnS2 heterojunction with enriched oxygen defects

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Chemical engineering Journal 2025年 516卷

作者： You, Feifei Li, Dazhao Wang, Dan Ge, Yuanyu Lu, Zhenqian Qi, Jian Li, Danyang College of Textile and Clothing Yancheng Institute of Technology Yancheng224051 China State Key Laboratory of Biochemical Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China School of Chemical Engineering University of Chinese Academy of Sciences Beijing100049 China Shandong Provincial Key Laboratory of Monocrystalline Silicon Semiconductor Materials and Technology Dezhou University Dezhou253023 China

Solar driving CO2 photoreduction represents a highly promising strategy that can not only reduce CO2 level in the atmosphere but also yield value-added chemicals. Herein, an urchin-like hollow structured hybrid with TiO2@SnS2 heterogeneous junction was designed and synthesized through a facile approach including hard-template method and hydrothermal process. When used as catalyst for photocatalytic CO2 reduction, the optimized sample exhibited exceptional activity with a CO yield rate of 52.86 µmol·g-1h−1 and durability during 4 cycles within 28 h. The enhanced performance could be attributed to i) the confinement effect of hollow structure enhancing the light capture and absorption owing to the multi-reflection/scattering of incident light in hollow cavity;ii) the constructed hetero-junction between TiO2 and SnS2 facilitating the transfer and separation of charge carriers and iii) photothermal effect induced by confinement effect of hollow structure through trapping the unused incident light and oxygen defects promoting the activation of CO2 molecules. We believed that this work could inspire further development in the field of synthesis of hollow structured catalysts as well as photocatalysis. © 2025 Elsevier B.V.

关键词： Titanium dioxide

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Vanadium Pentoxide Nanowires Preparation Via Kinetic Control of Vanadium Oxytrichloride Catalytic Oxidation with Apcvd

SSRN

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SSRN 2024年

作者： Fan, Chuanlin Ye, Lanshan Yue, Fen Chen, Chenchen Zhu, Qingshan Ma, Sugang Pan, Feng Ge, Yu State Key Laboratory of Mesoscience and Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China University of Chinese Academy of Sciences Beijing100049 China China University of Mining and Technology Beijing100083 China

Vanadium pentoxide nanowires were successfully fabricated using vanadium oxytrichloride oxidation with copper oxide nanoparticles serving as catalysts via atmospheric pressure chemical vapor deposition. Kinetic parameters such as temperature and flow velocity were proved to play important roles in the morphologic control of as-deposited product. Vanadium pentoxide nanowires with an average length of ~10 μm and a diameter of 50 - 100 nm, were obtained under the optimum conditions. A root growth mechanism of nanowires was proposed that precursor was readily captured by catalyst nanoparticles at the beginning of deposition, forming nucleation sites. Subsequently, the anisotropic growth of vanadium pentoxide is primarily governed by energy minimization under the reaction rate limited conditions. The presence of oxygen vacancies in the nanowires was confirmed by Raman, XPS and photoluminescence characterization, indicating promising applications in functional materials manufacture. The novel route for preparing vanadium pentoxide nanowires provides an alternative pathway for transitioning traditional vanadium industry towards advanced functional materials development. © 2024, The Authors. All rights reserved.

关键词： Nanowires

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Engineered microbial platform confers resistance against heavy metals via phosphomelanin biosynthesis

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Nature Communications 2025年第1期16卷 1-15页

作者： Ren, Xiaokang Zhao, Luyang Shen, Jintao Zhou, Peng Zhao, Kaili Yuan, Chengqian Xing, Ruirui Yan, Xuehai State Key Laboratory of Biopharmaceutical Preparation and Delivery Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China Center for Mesoscience Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China

Environmental concerns are increasingly fueling interest in engineered living materials derived from microbial sources. Melanin biosynthesis in microbes, particularly facilitated by recombinant tyrosinase expression, offers sustainable protection for the habitat of microorganisms against severe environmental stressors. However, there exists a vast urgency to optimize these engineered microbial platforms, which will amplify their protective capabilities, integrate multifaceted functions, and thereby expand their utility and effectiveness. Here, we genetically engineer microbial platforms capable of endogenously biosynthesizing phosphomelanin, a unique phosphorus-containing melanin. The ability to heterogeneously biosynthesize phosphomelanin endows the microbes with enhanced resistance to heavy metals, thus safeguarding their survival in adverse conditions. Furthermore, we upgrade these engineered microbes by integrating PET-degrading enzymes, thereby achieving effective integrated management of metallized plastic waste. This engineered microbial platform, with its phosphomelanin biosynthetic capabilities, presents significant opportunities for microbes to engage in bioengineering manufacturing, potentially serving as the next-generation guardians against global ecological challenges. © The Author(s) 2025.

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Micro reactors for measurement and analysis of thermochemical gas-solid reactions

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Resources Chemicals and Materials 2022年第2期1卷 152-166页

作者： Zhennan Han Junrong Yue Chao Wang Xi Zeng Jian Yu Fang Wang Yu Guan Xuejing Liu Fu Ding Liangliang Fu Xin Jia Xingfei Song Dingrong Bai Guangwen Xu Key Laboratory on Resources Chemicals and Material of Ministry of Education Shenyang University of Chemical TechnologyShenyang 110142China The State Key Laboratory of Multi-phase Complex System Institute of Process EngineeringChinese Academy of ScienceBeijing 100190China School of Ecology and Environment Beijing Technology and Business UniversityBeijing 100048China

Micro reactors are the essential part of thermal analysis techniques for characterizing gas-solid thermochemical reactions. The dynamic and diversified needs for investigating various complex materials and gas-solid reactions have led to the development of a variety of different microreactors over the years. Solid particles in microreactors are normally heated by furnaces from outside, resistive elements from inside, direct contact with bed particles, or other non-resistively methods. Solid particles can be fixed or fluidized in reactors where gas-solid contacts vary from diffusion-dominated to nearly diffusion-free conditions. Based on these characteristics, in this article we presented a broad classification for microreactors used for thermal analysis of gas-solid reactions. For each of the most popularly used microreactors, their features and limitations are briefly reviewed. By addressing the diversity of the microreactors used in the field of thermal analysis, the review aims at providing general guidance for the selection and operation of the microreactor to satisfy one's practical specific needs.

关键词： Microreactors Thermal analysis Gas-solid reaction Kinetics Mechanism

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Fouling Behavior of Nanofiltration Membrane During the Refining Treatment of Morphlines-Dominant Reverse Osmosis Concentrate

SSRN

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SSRN 2024年

作者： Li, Yahui Dong, Yanan Chen, Shangqing Wu, Yingqiu Wang, Junfeng Nie, Yi Beijing Key Laboratory of Ionic Liquids Clean Process State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences Beijing100190 China Innovation Academy for Green Manufacture Chinese Academy of Sciences Beijing100190 China University of Chinese Academy of Sciences Beijing100049 China Petrochemical Research Institute PetroChina Beijing102206 China School of Chemical Engineering and Pharmacy Hubei Key Lab of Novel Reactor & Green Chemical Technology Key Laboratory of Green Chemical Engineering Process Ministry of Education Wuhan Institute of Technology Wuhan430205 China

Nanofiltration (NF) has shown significant promise for separating morpholines with a molecular weight below 200 Da in refining reverse osmosis concentrate (ROC). However, its application is severely hampered by membrane fouling resulting from complex interactions between the membrane and organic/inorganic substances present in ROC. Our prior research identified the DK membrane as highly efficient in separating morpholine from high-saline NaCl-rich aqueous solutions during ROC treatment. Nevertheless, permeability notably decreased over prolonged operation. To ensure the long-term stability of nanofiltration operations, this study delves into the fouling behavior of individual substances present in hydrosaline organic solutions on nanofiltration membranes, aiming to elucidate the fouling mechanism. Consequently, we systematically investigated the effects of salts (NaCl and Na2SO4), organic substances (including N-(2-hydroxypropyl) morpholine (NMH) and 4-morpholineacetate (MHA)), and representative divalent ions (Ca2+ and Mg2+) on the performance and physicochemical properties of the DK membrane. Our findings revealed that both salts and organics induced swelling of the DK membrane, resulting in an enlargement of the mean effective pore size, thereby allowing more organic molecules to permeate the membrane pores. Notably, MHA caused irreversible pore blocking. Additionally, increasing Ca2+ concentrations led to gypsum scaling on the membrane surface, with NMH potentially acting as nuclei, expediting gypsum crystal formation during CaSO4 crystallization. In conclusion, this study systematically elucidated the fouling behavior of substances present in high-saline organic wastewater on DK membranes, proposing corresponding fouling mechanisms. These insights offer valuable guidance for membrane fouling control and cleaning in treating high salinity and organic wastewater. © 2024, The Authors. All rights reserved.

关键词： Nanofiltration

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