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Micro-flow structure at regime transition from bubbling to turbulent fluidization in a fluidized bed

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Particuology 2024年第6期89卷 117-130页

作者： chaoyu Yan Yue Yuan Xiaoyang Wei Jesse Zhu State Key Laboratory of Heavy Oil Processing Beijing Key Laboratory of Process Fluid Filtration and SeparationCollege of Mechanical and Transportation EngineeringChina University of PetroleumBeijing 102249China China Beacons Institute The University of NottinghamNingbo315100China Department of Chemical and Biochemical Engineering University of Western OntarioLondonOntarioN6A 5B9Canada

Gas-solid fluidized beds have found extensive utilization in frontline manufacturing,in particular as low-velocity beds.The fluidization status,the bubbling or turbulent flow regime and the transition in between,determine the system performance in practical applications.Though the convoluted hydrodynamics are quantitively evaluated through numerous data-processing methodologies,none of them alone can reflect all the critical information to identify the transition from the bubbling to the turbulent regime.Accordingly,this study was to exploit a coupling data processing methodology,in the combination of standard deviation,power spectrum density,probability density function,wavelet transform,and wavelet multiresolution method,to jointly explain the micro-flow structure at the regime transition from bubbling to turbulent fluidization.The transient differential pressure fluctuation was measured for the evaluation in a fluidized bed(0.267 m i.d.×2.5 m height)with FCC catalysts(d_(p)=65μm,ρ_(p)=1780kg/m^(3))at different superficial gas velocities(0.02–1.4 m/s).The results show that the onset of turbulent fluidization starts earlier in the top section of the bed than in the bottom section.The wavelet decomposition displays that the fluctuation of differential pressure mainly concentrates on the sub-signals with an intermediate frequency band.These sub-signals could be synthesized into three types of scales(micro-scale,meso-scale,and macro-scale),representing the multi-scale hydrodynamics in the fluidized bed.The micro-scale signal has the characteristic information of bubbling fluidization,and the characteristic information of turbulent fluidization is mainly represented by the meso-scale signal.This work provides a systematic comprehension of fluidization status assessment and serves as an impetus for more coupling analysis in this sector.

关键词： Flow regime transition Bubbling fluidization Turbulent fluidization Micro-flow structure Differential pressure fluctuation

Proton‑Prompted Ligand Exchange to Achieve High‑Efficiency CsPbI_(3) Quantum Dot Light‑Emitting Diodes

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Nano-Micro Letters 2024年第6期16卷 53-62页

作者： Yanming Li Ming Deng Xuanyu Zhang Lei Qian chaoyu Xiang Laboratory of Advanced Nano‑Optoelectronic Materials and Devices Qianwan Institute of CNITECHNingbo 315300People’s Republic of China Division of Functional Materials and Nanodevices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201People’s Republic of China Zhejiang Provincial Engineering Research Center of Energy Optoelectronic Materials and Devices Ningbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201People’s Republic of China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211ZhejiangPeople’s Republic of China University of Nottingham Ningbo China Ningbo 315100People’s Republic of China

CsPbI_(3)perovskite quantum dots(QDs)are ideal materials for the next generation of red light-emitting diodes.However,the low phase stability of CsPbI_(3)QDs and long-chain insulating capping ligands hinder the improvement of device performance.Traditional in-situ ligand replacement and ligand exchange after synthesis were often difficult to control.Here,we proposed a new ligand exchange strategy using a proton-prompted insitu exchange of short 5-aminopentanoic acid ligands with long-chain oleic acid and oleylamine ligands to obtain stable small-size CsPbI_(3)QDs.This exchange strategy maintained the size and morphology of CsPbI_(3)QDs and improved the optical properties and the conductivity of CsPbI_(3)QDs films.As a result,high-efficiency red QD-based light-emitting diodes with an emission wavelength of 645 nm demonstrated a record maximum external quantum efficiency of 24.45%and an operational half-life of 10.79 h.

关键词： CsPbI_(3) perovskite quantum dots Light-emitting diodes Ligand exchange Proton-prompted in-situ exchange

Endothelial METRNL determines circulating METRNL level and maintains endothelial function against atherosclerosis

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Acta Pharmaceutica Sinica B 2023年第4期13卷 1568-1587页

作者： Sili Zheng Zhiyong Li Jie Song Pin Wang Jian Xu Wenjun Hu Yi Shi Qi Qi Zhuwei miao Yunfeng Guan chaoyu miao Department of Pharmacology Second Military Medical University/Naval Medical UniversityShanghai 200433China Changhai Hospital Second Military Medical University/Naval Medical UniversityShanghai 200433China Zhongshan Hospital Fudan UniversityShanghai 200032China

METRNL is a recently identified secreted protein with emerging functions.This study is to find major cellular source of circulating METRNL and to determine METRNL novel function.Here,we show METRNL is abundant in human and mouse vascular endothelium and released by endothelial cells using endoplasmic reticulum-Golgi apparatus pathway.By creating endothelial cell-specific Metrnl knockout mice,combined with bone marrow transplantation to produce bone marrow-specific deletion of Metrnl,we demonstrate that most of circulating METRNL(approximately 75%)originates from the endothelial cells.Both endothelial and circulating METRNL decrease in atherosclerosis mice and patients.By generating endothelial cell-specific Metrnl knockout in apolipoprotein E-deficient mice,combined with bone marrow-specific deletion of Metrnl in apolipoprotein E-deficient mice,we further demonstrate that endothelial METRNL deficiency accelerates atherosclerosis.Mechanically,endothelial METRNL deficiency causes vascular endothelial dysfunction including vasodilation impairment via reducing eNOS phosphorylation at Ser1177 and inflammation activation via enhancing NFκB pathway,which promotes the susceptibility of atherosclerosis.Exogenous METRNL rescues METRNL deficiency induced endothelial dysfunction.These findings reveal that METRNL is a new endothelial substance not only determining the circulating METRNL level but also regulating endothelial function for vascular health and disease.METRNL is a therapeutic target against endothelial dysfunction and atherosclerosis.

关键词： METRNL Secreted protein Endothelium Endothelial function Bone marrow Atherosclerosis

Catalytic transformation of 4-nitrophenol into 4-aminophenol over ZnO nanowire array-decorated Cu nanoparticles

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Green Chemical Engineering 2024年第2期5卷 205-212页

作者： Anlin Feng chaoyu Lin Huiqin Zhou Weihong Jin Yidong Hu Dongyang Li Qingyang Li Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China School of Chemical Engineering and Technology Hebei University of TechnologyTianjin300401China Department of Chemical and Materials Engineering University of AlbertaEdmontonT6G 2H5Canada

To realize economical and effective removal of hazardous 4-nitrophenol from the environment,we developed an easily recyclable ZnO nanowire array decorated with Cu nanoparticles.Its salix argyracea-shaped structure not only provides a platform to achieve stable and good dispersion of Cu nanoparticles,but also offers a great deal of catalytically active sites.The density functional theory calculations reveal that ZnO and Cu have a very beneficial synergistic effect on their catalytic capability.This synergy is ascribed to the electronic localization occurring at ZnO/Cu interface,which helps improve Cu nanoparticle’s ability to adsorb electro-negatively 4-nitrophenolate ions and to capture hydrogen radicals,thereby accelerating the hydrogen transfer from metal hydride complex to 4-nitrophenol.Benefiting from these characteristics,it exhibits high efficiency and reusability towards the catalytic reduction of waste 4-nitrophenol to valuable 4-aminophenol with a rate constant of 43.02×10^(-3)s^(-1)and an average conversion of 96.5%in 90 s during 10 cycles.This activity is superior to that of most reported noble-or non-noble-metal powder,bulk,coating,and array catalysts,indicating its competitive advantages in cost and efficiency,as well as enticing application prospects.

关键词： ZnO nanowire Cu nanoparticle Nano-heterojunction 4-Nitrophenol catalytic reduction Density functional theory

Deciphering the high-carbonization-temperature triggered enzymatic activity of wool-derived N,S-co-doped carbon nanosheets

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Chinese Chemical Letters 2024年第3期35卷 182-188页

作者： Jiachen Zhao Deshuai Yu Jianmin Chen Shihao Lin Yonghua Tang chaoyu Fan Dongfang Zhou Youhui Lin Department of Physics Research Institute for Biomimetics and Soft MatterFujian Provincial Key Laboratory for Soft Functional Materials ResearchXiamen UniversityXiamen 361005China School of Pharmacy and Medical Technology Putian UniversityPutian 351100China Key Laboratory of Mental Health of the Ministry of Education NMPA Key Laboratory for Research and Evaluation of Drug Metabolism&Guangdong Provincial Key Laboratory of New Drug ScreeningSchool of Pharmaceutical SciencesSouthern Medical UniversityGuangzhou 510515China Key Laboratory of Pharmaceutical Analysis and Laboratory Medicine(Putian University) Fujian Province UniversityPutian 351100China

It is well-established that high carbonization temperature will trigger the enzyme-like activity of carbon-based materials.However,the catalytic mechanism is still ambiguous,which hinders the further rational design of nanomaterials as enzyme mimics.Hereby,N,S-rich carbonized wool nanosheets(CWs)were synthesized at different pyrolysis temperatures.As expected,only CWs treated with high-temperature possess intrinsic oxidase-and peroxidase-like activities.Meanwhile,density functional theory(DFT)calculations demonstrate that graphitic nitrogen and the co-existence of nitrogen and sulfur in the carbon matrix serve as the active sites for the enzyme-like process.More importantly,combining theoretical calculations and experimental observations,the high-temperature triggered catalytic mechanism can be ascribed to the fact that an appropriate high-temperature maximizes the graphitization degree to a certain extent,at which most of the catalytic active sites are well retained rather than evaporating.Moreover,coupling with excellent photothermal conversion efficiency and catalytic performance,CWs can be applied to photothermal-catalytic cancer therapy under near-infrared region(NIR)light irradiation.We believe this work will contribute to understanding the catalytic mechanism of carbon-based nanozymes and promote the development of new biomedical and pharmaceutical applications.

关键词： Carbon-based nanozyme Catalytic mechanism Density functional theory High-temperature carbonization

On the topological surface states of the intrinsic magnetic topological insulator Mn-Bi-Te family

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National Science Review 2024年第2期11卷 50-64页

作者： Yuan Wang Xiao-Ming Ma Zhanyang Hao Yongqing Cai Hongtao Rong Fayuan Zhang Weizhao Chen Chengcheng Zhang Junhao Lin Yue Zhao Chang Liu Qihang Liu chaoyu Chen Shenzhen Institute for Quantum Science and Engineering(SIQSE)and Department of Physics Southern University of Science and Technology(SUSTech)

We review recent progress in the electronic structure study of intrinsic magnetic topological insulators（MnBi2Te4）·（Bi2Te3）n（n = 0, 1, 2, 3） family. Specifically, we focus on the ubiquitously（nearly）gapless behavior of the topological Dirac surface state observed by photoemission spectroscopy, even though a large Dirac gap is expected because of surface ferromagnetic order. The dichotomy between experiment and theory concerning this gap behavior is perhaps the most critical and puzzling question in this frontier. We discuss various proposals accounting for the lack of magnetic effect on the topological Dirac surface state, which are mainly categorized into two pictures, magnetic reconfiguration and topological surface state redistribution. Band engineering towards opening a magnetic gap of topological surface states provides great opportunities to realize quantized topological transport and axion electrodynamics at higher temperatures.

关键词： intrinsic magnetic topological insulator topological surface states magnetic gap magnetic reconfiguration topological surface state redistribution van der Waals spacing expansion

五味子非药用部位活性成分和药理作用研究进展

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中草药 2024年第9期55卷 3179-3189页

作者：刘继艳王冰李超宇于淼哈尔滨商业大学药物工程技术研究中心黑龙江哈尔滨150076 哈尔滨商业大学食品工程学院黑龙江哈尔滨150076 国家教育部抗肿瘤天然药物工程研究中心黑龙江哈尔滨150076 黑龙江省肿瘤预防与抗肿瘤药物研究重点实验室黑龙江哈尔滨150076 哈尔滨商业大学药物研究所博士后科研工作站黑龙江哈尔滨150076

五味子Schisandra chinensis始载于《神农本草经》,具有收敛固涩、益气生津、补肾宁心的功效。在《中国药典》2020年版中规定五味子的药用部位是干燥成熟果实,含有木脂素、多糖、萜类及黄酮等化合物,具有调节中枢神经系统和内分泌系统... 详细信息

五味子Schisandra chinensis始载于《神农本草经》,具有收敛固涩、益气生津、补肾宁心的功效。在《中国药典》2020年版中规定五味子的药用部位是干燥成熟果实,含有木脂素、多糖、萜类及黄酮等化合物,具有调节中枢神经系统和内分泌系统、抗肿瘤、抗氧化、抗炎、抑菌等作用。近年来研究显示五味子藤茎、叶、果梗和根等非药用部位同样含有木脂素、多糖、萜类及黄酮等活性成分,其中一些活性成分含量高于药用部位,但非药用部位常作为杂质被废弃,不仅未得到充分利用还造成资源浪费。基于已公开发表的文献,对五味子非药用部位的活性成分和药理作用进行总结,为深入开发五味子非药用部位提供参考和数据支撑,为五味子非药用部位的综合利用打下基础。

关键词：五味子非药用部位木脂素多糖中枢神经系统抗肿瘤抗氧化

Properties of Ti-Based Hydrogen Storage Alloy

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Journal of Power and Energy Engineering 2024年第3期12卷 99-114页

作者： Rui Xu Tao Cheng chaoyu Li Xue Yang Junfeng Rong Sinopec Research Institute of Petroleum Processing Co. Ltd. Beijing China

An efficient and safe hydrogen storage method is one of the important links for the large-scale development of hydrogen in the future. Because of its low price and simple design, Ti-based hydrogen storage alloys are considered to be suitable for practical applications. In this paper, we review the latest research on Ti-based hydrogen storage alloys. Firstly, the machine learning and density functional theory are introduced to provide theoretical guidance for the optimization of Ti-based hydrogen storage alloys. Then, in order to improve the hydrogen storage performance, we briefly introduce the research of AB type and AB2 type Ti-based alloys, focusing on doping elements and adaptive after treatment. Finally, suggestions for the future research and development of Ti-based hydrogen storage alloys are proposed. .

关键词： Renewable Energy Hydrogen Storage Ti-Based Alloy Machine Learning

Thermal transport in composition graded silicene/germanene heterostructures

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Chinese Physics B 2024年第4期33卷 49-54页

作者：曹增强王超宇张宏岗游波倪宇翔 School of Physical Science and Technology Southwest Jiaotong UniversityChengdu 610031China Department of Materials Science and the Advanced Coatings Research Center of the China Educational Ministry Fudan UniversityShanghai 200433China Key Laboratory of High Performance Scientific Computation School of ScienceXihua UniversityChengdu 610039China

Through equilibrium and non-equilibrium molecular dynamics simulations,we have demonstrated the inhibitory effect of composition graded interface on thermal transport behavior in lateral heterostructures.Specifically,we investigated the influence of composition gradient length and heterogeneous particles at the silicene/germanene(SIL/GER)heterostructure interface on heat conduction.Our results indicate that composition graded interface at the interface diminishes the thermal conductivity of the heterostructure,with a further reduction observed as the length increases,while the effect of the heterogeneous particles can be considered negligible.To unveil the influence of composition graded interface on thermal transport,we conducted phonon analysis and identified the presence of phonon localization within the interface composition graded region.Through these analyses,we have determined that the decrease in thermal conductivity is correlated with phonon localization within the heterostructure,where a stronger degree of phonon localization signifies poorer thermal conductivity in the material.Our research findings not only contribute to understanding the impact of interface gradient-induced phonon localization on thermal transport but also offer insights into the modulation of thermal conductivity in heterostructures.

关键词： composition graded interface thermal transport phonon localization molecular dynamics