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Precise regulation of acid pretreatment for red mud SCR catalyst:Targeting on optimizing the acidity and reducibility

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Frontiers of Environmental Science & Engineering 2022年第7期16卷 61-71页

作者： Xiang zhang Yue Xuan Bin Wang Chuan Gao Shengli Niu Gaiju Zhao Dong Wang Junhua Li Chunmei Lu john C.Crittenden National Engineering Laboratory for Coal-Burning Pollutants Emission Reduction School of Energy and Power EngineeringShandong UniversityJinan250061China School of Civil and Environmental Engineering and the Brook Byers Institute for Sustainable Systems Georgia Institute of TechnologyAtlantaGA30332USA State Key Joint Laboratory of Environment Simulation and Pollution Control National Engineering Laboratory for Multi Flue Gas Pollution Control Technology and EquipmentSchool of EnvironmentTsinghua UniversityBeijing100084China Energy Institute Qilu University of Technology(Shandong Academy of Sciences)Jinan250013China

Red mud(RM),as an alkaline waste,was recently proved to be a promising substitute for the SCR *** could improve the acidity and reducibility of red mud,which were critical for SCR ***,the dealkalization effect depended on the reaction between acid solution and red *** this study,we realized the directional control of the chemical state of active sites through tuning the acid pretreatment(dealkalization)*** pretreatment endpoint was controlled at pH values of 3–5 with diluted nitric *** the pH values of red mud were 3 and 5(CRM-3 and CRM-5),activated catalysts showed NOx conversion above 90%at 275℃–475℃.The high initial reaction rate,Ce^(3+)/(Ce^(3+)+Ce^(4+))ratio,and surface acidity accounted for the excellent SCR performance of CRM-5 ***,more Fe^(3+) on the CRM-3 surface improved the NH_(3) *** was a strong interaction between Al and Fe in both CRM-5 and CRM-3 *** results showed that the adsorption capacity of the Al-O_(3)-Fe for NH_(3) and NO is stronger than that of Fe-O_(3)-Fe,which enhanced the NOx conversion of the ***,the almandine was formed in CRM-4,consumed part of Fe^(3+) and Al^(3+),and the interaction between Al and Fe was ***,deposited almandine on the catalyst surface covered the active sites,thus leading to lower NH_(3)-SCR activity.

关键词： Air pollution control Nitrogen oxides Selective catalytic reduction Red mud Solid waste utilization

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CFD Model of Dense Gas-solid Systems in Jetting Fluidized Beds

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Chemical Research in Chinese Universities 2002年第2期18卷 117-120页

作者： Kai zhang Jiyu zhang Biiang zhang john Yates Institute of Coal Chemistry Chinese Academy of SciencesP.O.Box 165Taiyuan 030001P.R.China Department of Chemical Engineering University College LondonLondonWC1E 7JEUK

A CFD code has been developed based on the conservation principles describing gas and solid flow in fluidized beds. This code is employed to simulate not only the spatiotemporal gas and solid phase velocities and voidage profiles in a two dimensional bed but also fluid dynamics in the jet region. The computational results show that gas flow direction is upward in the entire bed accompanied with random local circulations, whilst solid flow direction is upward at the center and downward near the wall. The radical reason of strong back mixing of solid particles and good transfer behavior between two phases is that the jet entrains solid particles. Numerical calculation indicates that gas velocity, solid velocity and pressure profile have a significant change when the voidage is 0 8. The simulated time averaged voidage profiles agree with the experimental results and simulated data reported by Gidaspow and Ettehadieh(1983). Therefore, CFD model can be regarded as a useful tool to study the jet characteristics in dense gas solid fluidized beds.

关键词： Jetting fluidized bed CFD model Gas solid dynamics Modified SIMPLE

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合理开发地球含量丰富金属的分子配合物用于电催化制氢

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Chinese Journal of Catalysis 2022年第12期43卷 3019-3045页

作者： john Daniel McCool Shiyuan zhang Inen Cheng Xuan Zhao 孟菲斯大学化学系美国田纳西州孟菲斯

基于公共健康和环境保护的原因,迫切需要用清洁和可再生能源取代传统的化石燃料.电化学水分解生产清洁的氢有望成为解决上述问题的可行方案.本综述介绍了用于在水或水/有机介质中电催化制氢的、基于地球上金属含量丰富的分子络合物的合... 详细信息

基于公共健康和环境保护的原因,迫切需要用清洁和可再生能源取代传统的化石燃料.电化学水分解生产清洁的氢有望成为解决上述问题的可行方案.本综述介绍了用于在水或水/有机介质中电催化制氢的、基于地球上金属含量丰富的分子络合物的合理设计.着重讨论了催化性能中的结构-功能关系,有助于设计未来的配体和催化剂.

关键词：制氢均相催化地球丰富金属电催化配体设计

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MXenes胶体氧化的调控策略及其对超级电容器性能的影响

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储能科学与技术 2022年第4期11卷 1165-1174页

作者：郭铁柱周迪张传芳瑞士联邦理工学院联邦材料科学与技术研究所瑞士杜本多夫CH-8600 西安交通大学电子科学与工程学院陕西西安710049

超级电容器作为能量存储器件,因具有较快的充放电速率、较高的功率密度和长的循环寿命等特点被广泛研究。MXenes因具有高电导率、高电化学活性、易成膜和亲水性等特点而被广泛应用在超级电容器领域,并展示了出色的储能性能。然而其面临... 详细信息

超级电容器作为能量存储器件,因具有较快的充放电速率、较高的功率密度和长的循环寿命等特点被广泛研究。MXenes因具有高电导率、高电化学活性、易成膜和亲水性等特点而被广泛应用在超级电容器领域,并展示了出色的储能性能。然而其面临着环境敏感、易氧化降解等严峻挑战,生成几乎没有电容量贡献的TiO_(2)等产物,严重阻碍了MXenes基超级电容器的发展。探索MXenes胶体稳定性的优化策略,并实现其稳定性的选择性调控,对提升MXenes在超级电容器及其他不同应用场合的性能具有重要的现实意义。为此本文简要总结了抑制MXenes氧化的策略,提出了稳定性选择性调控的总体方案,探讨了选择性调控对超级电容器性能的影响机制,为制备高性能MXenes基超级电容器提供思路。

关键词： MXenes 稳定性超级电容器氧化动力学

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Energy Absorption Performance of Bio-inspired Honeycombs:Numerical and Theoretical Analysis

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Acta Mechanica Solida Sinica 2021年第6期34卷 884-894页

作者： john Sherman Wen zhang Jun Xu Department of Mechanical Engineering and Engineering Science The University of North Carolina at CharlotteCharlotteNC 28223USA Vehicle Energy&Safety Laboratory(VESL) North Carolina Motorsports and Automotive Research CenterThe University of North Carolina at CharlotteCharlotteNC 28223USA

Energy absorption performance has been a long-pursued research topic in designing desired materials and structures subject to external dynamic *** by natural bio-structures,herein,we develop both numerical and theoretical models to analyze the energy absorption behaviors of Weaire,Floret,and Kagome-shaped thin-walled *** demonstrate that these bio-inspired structures possess superior energy absorption capabilities compared to the traditional thin-walled structures,with the specific energy absorption about 44%higher than the traditional *** developed mechanical model captures the fundamental characteristics of the bio-inspired honeycomb,and the mean crushing force in all three structures is accurately *** indicate that although the basic energy absorption and deformation mode remain the same,varied geometry design and the corresponding material distribution can further boost the energy absorption of the structure,providing a much broader design space for the next-generation impact energy absorption structures and systems.

关键词： Bio-inspired honeycomb Energy absorption Impact resistance Finite element analysis Modeling

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多组分燃料液滴高温蒸发耦合机制研究

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华南理工大学学报（自然科学版） 2023年第3期51卷 33-40,82页

作者：梅德清俞玥高亚平祁佳炜章传方江苏大学汽车与交通工程学院江苏镇江212013

以高挥发性的乙醇与低挥发性的加氢生物柴油和柴油构成的多组分混合燃料为研究对象,研究了单个液滴在高温下的内部蒸汽气泡动力学及蒸发特性。在恒温加热炉中,采用挂滴法结合高速显微成像技术,在773、873和973 K温度下,捕捉了加氢生物柴... 详细信息

以高挥发性的乙醇与低挥发性的加氢生物柴油和柴油构成的多组分混合燃料为研究对象,研究了单个液滴在高温下的内部蒸汽气泡动力学及蒸发特性。在恒温加热炉中,采用挂滴法结合高速显微成像技术,在773、873和973 K温度下,捕捉了加氢生物柴油-乙醇-柴油混合燃料液滴在蒸发过程中的形态变化,分析了液滴的归一化平方直径和寿命等特征。研究表明,在773 K下,蒸发过程较平稳,液滴体积均匀减小,而在973 K下,0.093 s时液滴内开始产生微小气泡并逐渐增大;在0.767 s时再次形成微小气泡,并于0.907 s时出现第2次破裂。升高环境温度有助于增加燃料液滴的蒸发速率,加剧蒸发过程中的微爆现象,一定程度上缩短了液滴的蒸发时间;蒸发过程中液滴内部的气泡增长与汽液界面的Rayleigh-Taylor不稳定性有关,且在液滴表面观察到了表面张力现象;与柴油相比,随着二元燃料中加氢生物柴油含量的增加,组分对蒸发的抑制作用更强,与二元燃料相比,三元燃料中的乙醇促进了微爆,缩短了液滴蒸发;三元燃料的液滴蒸发按序呈现乙醇主导、乙醇和柴油共同主导以及三者共同蒸发3个典型特征阶段。

关键词：三元燃料液滴蒸发微爆挂滴法

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Laser additive manufacturing for infrastructure repair:A case study of a deteriorated steel bridge beam

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Journal of Materials Science & Technology 2023年第23期154卷 149-158页

作者： Shengbiao zhang Peijun Hou Jiyun Kang Tianyi Li Shahryar Mooraj Yang Ren Catherine H.Chen A.john Hart Simos Gerasimidis Wen Chen Department of Mechanical and Industrial Engineering University of Massachusetts Amherst MA 01003 USA Department of Civil and Environmental Engineering University of Massachusetts Amherst MA 01003 SA Department of Materials Science and Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA X-ray Science Division Argonne National Laboratory Lemont IL 60439 USA Massachusetts Department of Transportation Boston MA 02116 USA Department of Mechanical Engineering Massachusetts Institute of Technology Cambridge MA 02139 USA Department of Physics City University of Hong Kong Kowloon Hong Kong China

As our transportation infrastructure ages,its deterioration is becoming a growing *** and effective methods for repair can reduce the need for time-and cost-intensive replacement of structures such as roadway *** this work,laser-based additive manufacturing(AM)was developed for the repair of damaged beams in steel bridges.A corroded structural beam of low-carbon A36 steel was selected for this case study and 316L stainless steel was used for repair due to its excellent mechanical properties and corrosion *** repair experiments were performed on specimens extracted from the beam,and prepared with various groove shapes(Rectangular,Trapezoidal,and U-shaped).More in-depth parametric and microstructural studies were carried out with a series of U-shaped specimens repaired with the linear laser input energy varied from 19.5 to 30.0 J mm–*** tensile properties of the repaired specimens and interface structures were also investigated in *** was found that the repaired specimens had a slightly higher tensile strength despite a reduction in tensile elongation compared to the A36 steel base *** influence of interfacial microstructure and heterogeneity on the mechanical properties of the repaired specimens was *** work suggests the promising potential to employ AM for structural repair and provides fundamental insights into processing-structure-property relationships in laser AM-repaired materials.

关键词： Additive manufacturing Structural repair Mechanical properties Transportation infrastructure Dissimilar joint

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Regrowth-free AlGaInAs MQW polarization controller integrated with a sidewall grating DFB laser

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Photonics Research 2023年第4期11卷 622-630页

作者： XIAO SUN SONG LIANG WEIQING CHENG SHENGWEI YE YIMING SUN YONGGUANG HUANG RUIKANG zhang JICHUAN XIONG XUEFENG LIU john HMARSH LIANPING HOU James Watt School of Engineering University of GlasgowGlasgow G128QQUK Institute of Semiconductors Chinese Academy of SciencesBeijing 100083China School of Electronic and Optical Engineering Nanjing University of Science and TechnologyNanjing 210094China

Polarization control is at the heart of high-capacity data optical communication systems,such as polarizationdivision multiplexers and Stokes vector modulation *** passive polarization control being mature,the realization of monolithically integrated polarization controllers and single longitudinal mode light sources,such as distributed-feedback(DFB)lasers,is of *** this research,we report an AlGaInAs multiple-quantum-well photonic integrated circuit device which can control the state of polarization of the output light source,consisting of a polarization mode converter(PMC),a differential phase shifter(DPS),and a sidewall grating DFB *** demonstrate an asymmetrical stepped-height ridge waveguide PMC to realize TE to TM polarization conversion and a symmetrical straight waveguide DPS to enable polarization rotation from approximately counterclockwise circular polarization to linear *** on the identical epitaxial layer scheme,all the PMC,DPS,and DFB lasers can be integrated monolithically using only a single step of metalorganic vapor-phase epitaxy and two steps of III-V material dry *** the DFB-PMC device,a high TE to TM polarization conversion efficiency(98.4%)over a wide range of DFB injection currents is reported at 1555 nm *** the DFB-PMC-DPS device,a nearly 60°rotation of the Stokes vector on the Poincarésphere was obtained with a range of bias voltage from 0 to-3.0 V at a laser drive current of 170 mA.

关键词： polarization waveguide rotation

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Limitations of current liver transplant immunosuppressive regimens: renal considerations

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Hepatobiliary & Pancreatic Diseases International 2017年第1期16卷 27-32页

作者： Wei zhang john Fung Department of Hepatobiliary Pancreatic Surgery First Affiliated Hospital Zhejiang University School of Medicine Division of Transplant Surgery University of Chicago

BACKGROUND： The use of calcineurin inhibitor （CNI）-based immunosuppressive regimens following liver transplantation （LTx） has improved the outcomes of the recipients. However, CNI has nephrotoxicity and causes shortand long-term renal complications. The progressive structural changes can be irreversible in the long-term, leading to chronic kidney dysfunction. The present review was to evaluate the different strategies of CNI application to renal function in liver recipients. DATA SOURCES： PubMed database was searched for relevant articles in English on the issue of immunosuppressive regimen and kidney injury that related to early minimization of CNI after LTx. RESULTS： Total avoidance of CNI from post-LTx immunosuppressive regimens has been associated with unacceptable high rates of acute, steroid resistant rejections; late conversion from CNI to non-nephrotoxic immunosuppressant failed to recover renal function. Early CNI minimization and conversion to non-nephrotoxic immunosuppressant, although had no effect on patient survival rates, improved glomerular filtration rate. The combination of everolimus （a mammalian target of rapamycin inhibitor） and tacrolimus not only maintains immunosuppressive efficacy but also minimizes kidney injury. CONCLUSIONS： Up to now, protocols entirely avoiding CNI have not passed the primary safety endpoint of patient and graft survival, as well as the FDA mandated endpoint of biopsy proven acute rejection. Thus, early CNI minimization after LTx is the most rational approach preserving post-transplant renal function.

关键词： liver transplantation immunosuppression chronic kidney disease

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Single-atom metal-nitrogen-carbon catalysts energize single molecule detection for biosensing

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InfoMat 2023年第6期5卷 44-65页

作者： Xianyang zhang Pengfei Chen Siwuxie He Bowen Jiang Yong Wang Yonghua Cheng Jian Peng Francis Verpoort john Wang Zongkui Kou State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhanthe People's Republic of China “ZhuCai”Center of Innovation and Entrepreneurship Wuhan University of TechnologyWuhanthe People's Republic of China West China School of Pharmacy Sichuan UniversityChengduthe People's Republic of China Department of Materials Science and Engineering Faculty of EngineeringNational University of SingaporeSingapore Institute of Materials Research and Engineering A*StarSingapore

Biosensors featuring single molecule detection present huge opportunities as well as challenges in food safety inspection,disease diagnosis,and environmental ***-molecule detection is largely lacking of high enough activity,precision molecule selectivity,and understanding in the exact operating ***-atom catalysts(SACs),especially those metals-nitrogen-carbon that mimic the natural metalloenzyme structure,and with well-defined metal atom bond configurations,high level of molecular selectivity,and easy fabrication,endow single molecule detections with practical-use *** recent advances in single-atom catalysts also present new pathways in the key mechanism *** this short review,we will first visit the brief history and advantages of SACs that have been explored only recently for molecule-scale biosensors,where they are analogous and also differentiated from those nanozymes and natural *** applications in electrochemical,photochemical,and photoelectrochemical sensors are then discussed comprehensively by focusing on the different molecule-scale sensing modes in achieving local coordination-modulated signal ***,we identify new opportunities and challenges faced by these SACs-based single molecule detections in the further development of biosensors.

关键词： biosensors metal-nitrogen-carbon nanozyme single molecule detection single-atom catalysts

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