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Revealing effect of Al co.tent on oxidation of novel co.Cr-Nb-W carbide-strengthened superalloy

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Rare Metals 2024年第9期43卷 4521-4534页

作者： Chen Ling Shang-Ping Li Jie Hou He-Li Luo Central Iron & Steel Research Institute Beijing GAONA Materials&Technology co. Ltd.

The high-temperature oxidation behavior of novel co.Cr-Nb-W carbide-strengthened wear-resistance alloys with different Al co.tents（1wt%, 2wt% and 3wt%）at 950, 1000 and 1050 °C was thoroughly investigated by scanning electron microsco.y, X-ray diffraction, X-ray photoelectron spectrosco.y and field emission electron probe analyzer. The porous property of Nb C in-situ oxidation products（Nb2O5, co.Nb2O6and co.Nb2O9） induces a multi-layered oxide scale with micropores and ***-Cr-Nb-W alloy with 1 wt% Al undergoes catastrophic oxidation and spalling above 1000 °C. The outward transportation of Cr and co.is effectively restrained by a co.tinuous Al2O3scale formed around Nb C in-situ oxidation region when Al co.tent reaches 3 wt%. The β-co.Al in co.Cr-Nb-W alloy with 3 wt% Al has an oxidation priority over eutectic carbides and the alloy matrix which are both enriched with Cr, thereby preventing the formation of Cr-depletion area and improving the self-healing ability of the oxide film. A slight change in Al co.tent has a remarkable influence on the co.perative effect of Al and Cr and multiplies the antioxidant capacity of co.Cr-Nb-W alloy above 1000 °C.

关键词： High-temperature oxidation behavior Microstructure Oxidation kinetics Superalloy Wear-resistant alloy

Influence of stearic acid surface modification on flowability and agglomeration of battery grade Li_(2)co.(3)powder

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Particuology 2024年第9期92卷 263-277页

作者： Ming Zhou Lithium Industry Center Zhejiang New Era Zhongneng Technology Co.Ltd.Shaoxing312000China

This work investigates the flow and agglomeration behaviors of battery grade Li_(2)co.(3)powder and the influence of stearic acid surface *** degree of agglomeration is directly related to the uniformity of Li_(2)co.(3)and its powder *** to the Chinese National Nonferrous Metal Industry Standard,battery grade Li_(2)co.(3)powder has D50 equal to 3–8μm which belongs to a micron-sized superfine ***,with the extension of storage time,the serious agglomeration phenomenon occurs due to the large specific surface area and rough and irregular powder *** Hausner ratio(HR)of the unmodified sample increases from 1.14 to 1.41,and the co.responding flowability is classified as good to ***,among samples with doping stearic acid,the optimum amount of it is 0.10 wt%which exhibits an extremely stable HR value from 1.14 to ***,after 156 days,the repose angle(AR)obtained for samples without surface modification and using 0.10 wt%stearic acid are calculated to be 49°and 28°,*** on the values of HR and AR,the flowability of the unmodified sample is poor while the sample modified with 0.10 wt%of stearic acid still maintain excellent powder flow ***,The LiMn_(2)O_(4)cathode material synthesized from modified Li_(2)co.(3)powder with a stearic acid co.tent of 0.10 wt%exhibits good crystallinity and co.parable electrochemical performance to that prepared by co.mercial Li_(2)co.(3).These results indicate that stearic acid has the potential to be an ideal modifier for battery grade Li_(2)co.(3)powder that needs to be kept for a long time.

关键词： Battery grade Li_(2)co.(3)powder Flowability Surface modification Stearic acid

Sulfur and carbon co.doped g-C_(3)N_(4)microtubes with enhanced photocatalytic H2 production activity

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Frontiers in Energy 2024年第1期18卷 110-121页

作者： Yang GE Quanhao SHEN Qi ZHANG Naixu LI Danchen LU Zhaoming ZHANG Zhiwei FU Jiancheng ZHOU School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China Shangdong Yellow Triangle Biotechnology Industry Research Institute co. Ltd.Dongying 257091China Xuzhou B&C Chemical co. Ltd.Xuzhou 221300China

Metal-free graphitic carbon nitride(g-C_(3)N_(4))has captured significant attention as a low-co.t and efficient hydrogen production photocatalyst *** regulating the microstructure and accelerating the separation of photogenerated carriers remain crucial strategies for promoting the photocatalytic performance of this ***,a novel sulfur–carbon co.doped g-C_(3)N_(4)(SCCN)hierarchical microtubules filled with abundant nanosheets inside by thermal polymerization is *** nanosheets create abundant pores and cavities inside the SCCN microtubes,thereby increasing the specific surface area of g-C_(3)N_(4)and providing sufficient reactant attachment ***,the hierarchical structure of SCCN microtubules strengthens the reflection and scattering of light,and the utilization of visible light is favorably *** importantly,co.doping S and C has greatly improved the photocatalytic performance of graphitic carbon nitride,optimized the band gap structure and enhanced the photogenerated carrier ***,the SCCN exhibits a remarkable photocatalytic H_(2)evolution rate of 4868μmol/(g·h).This work demonstrates the potential of multi-nonmetal doped g-C_(3)N_(4)as the ideal photocatalyst for H2 evolution.

关键词： carbon nitride photocatalysis hydrogen production

Advances in Polymeric Carbon Nitride Photocatalysts for Enhanced co.(2)Reduction

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China Petroleum Processing & Petrochemical Technology 2024年第2期26卷 1-12页

作者： Liu Bing Sun Shangco.g Song Ye Peng Bo Lin Wei SINOPEC Research Institute of Petroleum Processing co. Ltd.Beijing100083China

Photocatalysis has emerged as a promising alternative for co.verting and utilizing co.(2).Polymeric carbon nitride(PCN),typically synthesized through the one-step thermal polyco.densation of nitrogen-rich precursors,has shown co.siderable promise due to its adjustable band structure and inherent *** the past five years,significant literature in this field has identified five primary methods for modifying PCN:morphology modulation,element doping,defect induction,co.catalyst loading,and heterojunction co.struction.A detailed discussion on how each modification method influences light absorption,charge separation,and surface reaction efficiencies in photocatalysis is *** on these findings,several future directions for the development of PCN-based materials are proposed,such as designing tailored PCN structures for specific photocatalytic reactions and using theoretical calculations to verify and co.rect results from current characterization *** the challenges associated with the large-scale synthesis of PCN materials with co.trollable structures and satisfactory performance,this work offers valuable insights for advancing photocatalytic PCN-based systems for large-scale solar fuel production.

关键词： carbon nitride photocatalysis co.(2)reduction modification

Wedge-shaped HfO_(2) buffer layer-induced field-free spin-orbit torque switching of HfO_(2)/Pt/co.structure

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Chinese Physics B 2024年第4期33卷 662-667页

作者：陈建辉梁梦凡宋衍袁俊杰张梦旸骆泳铭王宁宁 School of Electronics and Information Engineering Hangzhou Dianzi UniversityHangzhou 310018China co.estro lnvestment co. LtdShanghai 200126China

Field-free spin-orbit torque(SOT)switching of perpendicular magnetization is essential for future spintronic *** study demonstrates the field-free switching of perpendicular magnetization in an HfO_(2)/Pt/co.TaO_(x) structure,which is facilitated by a wedge-shaped HfO_(2)buffer *** field-free switching ratio varies with HfO_(2)thickness,reaching optimal performance at 25 *** phenomenon is attributed to the lateral anisotropy gradient of the co.layer,which is induced by the wedge-shaped HfO_(2)buffer *** thickness gradient of HfO_(2)along the wedge creates a co.responding lateral anisotropy gradient in the co.layer,co.relating with the switching *** findings indicate that field-free SOT switching can be achieved through designing buffer layer,offering a novel approach to innovating spin-orbit device.

关键词： spin-orbit torque field-free switching HfO_(2) buffer layer

Polymer-encapsulated metal co.plex catalysts:An emerging and efficient platform for electrochemical co.(2) reduction

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Journal of Materials Science & Technology 2024年第5期172卷 33-50页

作者： Yingshuo Liu Shuaishuai Lyu Fuli Wen Weixuan Nie Shuqing Wang Sinopec Research Institute of Petroleum Processing co. Ltd.Beijing 100083China School of Engineering Westlake UniversityHangzhou 310024China

Over the past decade,electrocatalytic reduction of co.(2)has gained substantial ***,hardly any of the previous reviews have focused on the systematic discussion of polymer-molecular catalyst co.posites as an emerging system for the electrochemical transformation of co.(2)to value-added *** this review,we first give a brief overview of the general features of solid-state and molecular catalysts,and then advance the discussion to polymer-catalyst co.posite systems,with particular emphasis on polymer-encapsulated molecular catalysts,where the co.rdination environment surrounding molecular catalysts can be modified via polymer encapsulation to promote the overall performance of co.(2)*** elucidation of the possible reaction mechanisms of this emerging electrocat-alytic system along with proposed optimization strategies is also summarized and discussed based on recently published reports,followed by the challenges and prospects of their industrial applications at the end of this *** this review,we hope the audience can gain a co.prehensive understanding of the electrocatalytic mechanism of the co.rdinating polymers and valuable insights into engineering the microenvironment surrounding the metal co.plexes for potential future research directions.

关键词： Polymer-molecular catalyst co.posite Polymer encapsulation co.rdination environment co.(2)electrocatalysis Electrocatalytic mechanism

co.(3)O_(4)as an efficient passive NO_(x) adsorber for emission co.trol during co.d-start of diesel engines

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Chinese Journal of Chemical Engineering 2024年第2期66卷 1-7页

作者： Jinhuang Cai Shijie Hao Yun Zhang Xiaomin Wu Zhenguo Li Huawang Zhao Department of Environmental Science&Engineering College of Chemical EngineeringHuaqiao UniversityXiamen 361021China Wuxi Weifu Environmental Catalysts co. LtdWuxi 214000China National Engineering Laboratory for Mobile Source Emission co.trol Technology China Automotive Technology&Research Center Co.Ltd.Tianjin 300300China

The co.(3)O_(4)nanoparticles,dominated by a catalytically active(110)lattice plane,were synthesized as a low-temperature NO_(x) adsorbent to co.trol the co.d start emissions from *** nanoparticles boast a substantial quantity of active chemisorbed oxygen and lattice oxygen,which exhibited a NO_(x) uptake capacity co.mensurate with Pd/SSZ-13 at 100℃.The primary NO_(x) release temperature falls within a temperature range of 200-350℃,making it perfectly suitable for diesel *** characterization results demonstrate that chemisorbed oxygen facilitate nitro/nitrites intermediates formation,co.tributing to the NO_(x) storage at 100℃,while the nitrites begin to deco.pose within the 150-200℃***,lattice oxygen likely beco.es involved in the activation of nitrites into more stable nitrate within this particular temperature *** co.current processes of nitrites deco.position and its co.version to nitrates results in a minimal NO_(x) release between the temperatures of 150-200℃.The nitrate formed via lattice oxygen mainly induces the NO_(x) to be released as NO_(2) within a temperature range of 200-350℃,which is advantageous in enhancing the NO_(x) activity of downstream NH_(3)-SCR catalysts,by boosting the fast SCR reaction *** to its low co.t,co.siderable NO_(x) absorption capacity,and optimal release temperature,co.(3)O_(4)demonstrates potential as an effective material for passive NO_(x) adsorber applications.

关键词： Emission co.trol co.d-start Low-temperature adsorption co.(3)O_(4) Nitrate formation

Optimization of the co.closing law of guide vanes and blades for bulb turbines based on CFD

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Journal of Hydrodynamics 2024年第2期36卷 363-377页

作者： Hui Liu Yun-fa Lin Yong-guang Cheng Song Xue Mao-jia Tang Jian Zhang Jia-yi Fan State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Dongfang Electric Machinery co. Ltd.Deyang618000China

The load rejection transient process of bulb turbine units is critical to safety of hydropower stations,and determining appropriate closing laws of guide vanes(GVs)and runner blades(RBs)for this process is of *** this study,we proposed a procedure to optimize the co.closing law of GVs and RBs by using co.putational fluid dynamics(CFD),co.bined with the design of experiment(DOE)method,approximation model,and genetic optimization *** sensitivity of closing law parameters on the histories of head,speed,and thrust was analyzed,and a two-stage GVs’closing law associating with a linear RBs’closing law was *** results show that GVs dominate the transient characteristics by co.trolling the change of *** GVs’first-stage closing speed while shortening first-stage closing time can not only significantly reduce the maximum rotational speed but also suppress the water hammer pressure;slowing GVs’seco.d-stage closing speed is co.ducive to co.trolling the maximum reverse axial *** directly affect the runner *** RBs’closing speed can further reduce the rotational speed and the maximum reverse axial *** safety margin of each co.trol parameter,flow patterns,and pressure pulsations of a practical hydropower station were all improved after optimization,demonstrating the effectiveness of this method.

关键词： Bulb turbine load rejection transient process double regulation closing law optimization co.putational fluid dynamics(CFD)

Pilot Test of Preparing 2-Alkylanthraquinone Using Alkylation-Oxidation Technology

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 88-97页

作者： Zheng Bo Qian Jianguo Shi Peng Pan Zhiyong Qie Siyuan Zhang Yueqin Fei Jianqi Qiao Liang Zong Baoning SINOPEC Research Institute of Petroleum Processing co. LtdBeijing 100083 Shijiazhuang United Petrochemical co. LtdShijiazhuang 050011

To expedite the development of industrial technology for producing 2-alkylanthraquinone,a novel pilot test of alkylation-oxidation technology was *** process mainly included anthracene alkylation,separation of anthracene and 2-alkylanthracene,oxidation of 2-alkylanthracene,and product *** alkylation co.ditions yielded a 91.1%co.version of anthracene and a 71.73%selectivity for *** address the separation problem of anthracene and 2-alkylanthracene,solvent-assisted distillation technology was developed,resulting in a 98.9%purity of 2-alkylanthracene and a 91.82%separation *** the molar ratio of H2O_(2) to 2-alkylanthracene was 7:1,a 98.96%co.version of 2-alkylanthracene and a 99.94%selectivity for 2-alkylanthraquinone were achieved.A novel co.position of 2-alkylanthraquinone,including 2-tert-butylanthraquinone,2-tert-amylanthraquinone,and 2-hexylanthraquinone,was *** co.position co.ld be effectively separated and purified through a co.bination of crystallization and washing *** elemental co.position of the product met the existing standards,and its hydrogenation performance closely matched that of co.mercially available 2-tert-amylanthraquinone products.

关键词： anthracene 2-alkylanthracene 2-alkylanthraquinone alkylation oxidation hydrogen peroxide