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Phase-field lattice-Boltzmann study on fully coupled thermal-solute-convection dendrite growth of Al-Cu alloy

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China Foundry 2024年第2期21卷 125-136页

作者： Yin-qi Qiu Meng-wu wu xun-peng Qin Shou-mei Xiong Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Longzhong Laboratory Xiangyang 441000HubeiChina School of Materials Science and engineering Tsinghua UniversityBeijing 100084China

Dendrite growth is a complex liquid-solid phase transition process involving multiple physical factors.A phase-field lattice-Boltzmann method was developed to simulate the two-and three-dimension dendrite growth of Al-Cu alloy.The effect of fully coupled thermal-solute-convection interaction on the dendrite growth was investigated by incorporating a parallel-adaptive mesh refinement algorithm into the numerical model.By accurately reproducing the latent heat release,solute diffusion and convective transport behaviors at the liquidsolid interface,the interaction mechanism among thermal-solute-convection transport as well as their coupling effects on the dendrite growth dynamics were discussed.The simulation results show that the release of latent heat slows down the dendrite growth rate,and both natural and forced convection disrupt the symmetrical growth of dendrites.Their combination makes the growth of dendrites more complex,capturing important physical aspects such as recalescence,dendrite tip splitting,dendrite tilting,dendrite remelting,and solute plume in the simulation case.Based on the robustness and powerful ability of the numerical model,the formation mechanisms of these physical aspects were revealed.

关键词： simulation phase field dendrite growth thermal-solute-convection interaction

Modified electronic structure and enhanced hydroxyl adsorption make quaternary Pt-based nanosheets efficient anode electrocatalysts for formic acid-/alcohol-air fuel cells

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Journal of energy Chemistry 2024年第5期92卷 142-150页

作者： Fengling Zhao Qiang Yuan Siyang Nie Liang wu xun Wang State-Local Joint Laboratory for Comprehensive Utilization of Biomass Center for R&D of Fine ChemicalsCollege of Chemistry and Chemical EngineeringGuizhou UniversityGuiyang 550025GuizhouChina Key Lab of Organic Optoelectronics&Molecular engineering Tsinghua UniversityBeijing 100084China School of Chemistry and Chemical engineering Shanghai Jiao Tong UniversityShanghai 200240China

Surface/interface engineering of a multimetallic nanostructure with diverse electrocatalytic properties for direct liquid fuel cells is desirable yet challenging.Herein,using visible light,a class of quaternary Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)ultrathin nanosheets is fabricated and used as high-performance anode electrocatalysts for formic acid-/alcohol-air fuel cells.The modified electronic structure of Pt,enhanced hydroxyl adsorption,and abundant exterior defects afford Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C high intrinsic anodic electrocatalytic activity to boost the power densities of direct formic acid-/methanol-/ethanol-/ethylene glycol-/glycerol-air fuel cells,and the corresponding peak power density of Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C is respectively 129.7,142.3,105.4,124.3,and 128.0 mW cm^(-2),considerably outperforming Pt/C.Operando in situ Fourier transform infrared reflection spectroscopy reveals that formic acid oxidation on Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)/C occurs via a CO_(2)-free direct pathway.Density functional theory calculations show that the presence of Ag,Bi,and Te in Pt_(1)Ag_(0.1)Bi_(0.16)Te_(0.29)suppresses CO^(*)formation while optimizing dehydrogenation steps and synergistic effect and modified Pt effectively enhance H_(2)O dissociation to improve electrocatalytic performance.This synthesis strategy can be extended to 43 other types of ultrathin multimetallic nanosheets(from ternary to octonary nanosheets),and efficiently capture precious metals(i.e.,Pd,Pt,Rh,Ru,Au,and Ag)from different water sources.

关键词： Pt-based nanosheets Modifiedelectronic structure enhanced hydroxyl adsorption Formicacidand alcohol oxidation Direct liquid fuel cells

Metal/covalent organic frameworks for aqueous rechargeable zinc-ion batteries

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Science China Chemistry 2024年第1期67卷 247-259页

作者： Hu Hong xun Guo Jiaxiong Zhu Zhuoxi wu Qing Li Chunyi Zhi Department of Materials Science and engineering City University of Hong KongHong Kong 999077China

Lithium-ion batteries(LIBs)have become one of the most successful energy storage systems due to their high operating voltage,high energy density,and long cycle life.However,with the widespread use of LIBs in recent decades,lithium resources are at risk of being exhausted.Therefore,it is necessary to find a substitute for LIBs to meet the needs of future large-scale energy storage systems.Because of their competitiveness,low cost,and high safety,aqueous rechargeable zinc-ion batteries(ARZIBs)are regarded as promising components in the post-lithium-ion-battery era.Given the tunable composition,ordered porous channels,and controllable structure of metal-organic frameworks(MOFs)and covalent organic frameworks(COFs),these frameworks are viewed as potential materials for developing high-performance ARZIBs.In this review,we focus on the recent developments in the applications of MOF-/COF-based materials in ARZIBs,including in electrode materials,anode modifications,separators,and solid electrolytes.We then focus on the critical factors and optimization techniques of MOF-/COF-based materials that affect the performance of ARZIBs.Finally,we conclude with some projections for the expansion of ARZIBs containing MOF-/COF-based materials.

关键词： metal/covalent organic frameworks aqueous zinc-ion batteries electrode materials anode modifications separators electrolytes

Recent advances in bioinspired vision systems with curved imaging structures

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Rare Metals 2024年第4期43卷 1407-1434页

作者： Ze-Ping He xun Han Wen-Qiang wu Zhang-Sheng Xu Cao-Feng Pan CAS Center for Excellence in Nanoscience Beijing Key Laboratory of Micro-Nano Energy and SensorBeijing Institute of Nanoenergy and NanosystemsChinese Academy of Sciences School of Nanoscience and Technology University of Chinese Academy of Sciences ZJU-Hangzhou Global Scientific and Technological Innovation Center School of Micro-Nano ElectronicsZhejiang University Institute of Microscale Optoelectronics Shenzhen University

Limited by the planar imaging structure,the commercial camera needs to introduce additional optical elements to compensate for the curved focal plane to match the planar image sensor.This results in a complex and bulky structure.In contrast,biological eyes possess a simple and compact structure due to their curved imaging structure that can directly match with the curved focal plane.Inspired by the structures and functions of biological eyes,curved vision systems not only improve the image quality,but also offer a variety of advanced functions.Here,we review the recent advances in bioinspired vision systems with curved imaging structures.Specifically,we focus on their applications in implementing different functions of biological eyes,as well as the emerging curved neuromorphic imaging systems that incorporate bioinspired optical and neuromorphic processing technologies.In addition,the challenges and opportunities of bioinspired curved imaging systems are also discussed.

关键词： Bioinspired Curved vision system Compound eye Chambered eye Neuromorphic

Strip flatness prediction of cold rolling based on ensemble methods

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Journal of Iron and Steel Research(International) 2024年第1期31卷 237-251页

作者： wu-quan Yang Zhi-ting Zhao Liang-yu Zhu xun-yang Gao Li Wang School of Mechanical and Power engineering Shenyang University of Chemical TechnologyShenyang110142LiaoningChina

Aiming at the problem of insufficient prediction accuracy of strip flatness at the outlet of cold tandem rolling,the prediction performance of strip flatness based on different ensemble methods was studied and a high-precision prediction ensemble model of strip flatness at the outlet was established.Firstly,based on linear regression(LR),K nearest neighbors(KNN),support vector regression,regression trees(RT),and backpropagation neural network(BPN),bagging,boosting,and stacking ensemble methods were used for ensemble experiments.Secondly,three existing ensemble models,i.e.,random forest,extreme random tree(ET)and extreme gradient boosting,were used to conduct experiments and compare the results.The research shows that bagging,boosting,and stacking three ensemble methods have the most significant improvement in the prediction accuracy of the regression trees model,which is increased by 5.28%,6.51%,and 5.32%,respectively.At the same time,the stacking ensemble method improves both the simple model and the complex model,and the improvement effect on the simple base model is the greatest,which is 4.69%higher than that of the base model KNN.Comparing all of the ensemble models,the stacking ensemble model of level-1(ET,AdaBoost-RT,LR,BPN)paired with level-2(LR)was discovered to be the best model(EALB-LR)and can be further studied for industrial applications.

关键词： Tandem cold rolling Flatness prediction Machine learning ensemble method

新型热绝缘纤维:可针织和编织的仿北极熊毛气凝胶纤维

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科学通报 2024年第12期69卷 1520-1522页

作者：吴逊恩张莹莹清华大学化学系北京100084

保暖织物在人类生活中扮演着不可或缺的重要角色.传统保暖织物通常由天然纤维(棉、麻、蚕丝)或人造纤维(聚酯、尼龙、聚丙烯腈、聚氨酯)构成.随着时代发展,传统保暖织物的性能已经不能满足日益提高的特别是面对极端复杂环境的保暖需求.... 详细信息

保暖织物在人类生活中扮演着不可或缺的重要角色.传统保暖织物通常由天然纤维(棉、麻、蚕丝)或人造纤维(聚酯、尼龙、聚丙烯腈、聚氨酯)构成.随着时代发展,传统保暖织物的性能已经不能满足日益提高的特别是面对极端复杂环境的保暖需求.气凝胶纤维是一种具有三维多孔网络结构的纤维,具有极高的孔隙率、极大的比表面积和极低的密度,是一种理想的绝热纤维,具有用于高性能保暖织物的潜力.然而,气凝胶纤维通常强度低、韧性差,被加工应用的能力较差,限制了其应用于保暖衣物[1].在过去10年里,研究者基于各种材料,包括碳纳米管、凯夫拉、聚酰亚胺、纤维素和石墨烯等,通过溶胶凝胶转变和特定的干燥方法,并通过结构设计成功制备了具有一定力学柔韧性(可弯曲、打结)的气凝胶纤维[2].但是,上述方法获得的气凝胶纤维的力学性能仍然无法满足织造(编织和针织)的要求,更无法满足耐水洗、耐磨等实用性织物的要求.

关键词：凝胶纤维保暖织物天然纤维绝缘纤维加工应用溶胶凝胶转变凯夫拉结构设计

Effects of Hydrogen Charging Time and Pressure on the Hydrogen Embrittlement Susceptibility of X52 Pipeline Steel Material

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Acta Metallurgica Sinica(english Letters) 2024年第2期37卷 293-307页

作者： Hong-Jiang Wan Xiao-Qi wu Hong-Liang Ming Jian-Qiu Wang en-Hou Han School of Materials Science and engineering University of Science and Technology of ChinaShenyang110016China CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and engineering Northeastern UniversityShenyang110819China Institute of Corrosion Science and Technology Guangzhou510530China

The effects of hydrogen charging time and pressure on the hydrogen embrittlement(HE)susceptibility of X52 pipeline steel material are studied by slow strain rate tensile tests.The fracture morphologies of the specimens are observed by scanning electron microscopy.The HE susceptibility of the X52 pipeline steel material increases with an increase in both hydrogen charging time and hydrogen pressure.At a charging time of 96 h,the HE susceptibility index reaches 45.86%,approximately 3.6 times that at a charging time of 0 h.Similarly,a charging pressure of 4 MPa results in a HE susceptibility index of 31.61%,approximately 2.5 times higher than that at a charging pressure of 0.3 MPa.

关键词： Hydrogen embrittlement X52 pipeline steel material Tubular specimen Hydrogen charging time Hydrogen charging pressure

Investigation of oxy-fuel combustion for methane and acid gas in a diffusion flame

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Chinese Journal of Chemical engineering 2024年第1期65卷 106-116页

作者： Songling Guo xun Tao Fan Zhou Mengyan Yu Yufan wu Yunfei Gao Lu Ding Fuchen Wang Institute of Clean Coal Technology East China University of Science and TechnologyShanghai 200237China

Co-combustion of methane(CH4)and acid gas(AG)is required to sustain the temperature in Claus reaction furnace.In this study,oxy-fuel combustion of methane and acid gas has been experimentally studied in a diffusion flame.Three equivalence ratios(ER=1.0,1.5,2.0)and CH_(4)-addition ratios(CH_(4)/AG=0.3,0.5,0.7)were examined and the flame was interpreted by analyzing the distributions of the temperature and species concentration along central axial.CH_(4)-AG diffusion flame could be classified into three sections namely initial reaction,oxidation and complex reaction sections.Competitive oxidation of CH_(4)and H_(2)S was noted in the first section wherein H_(2)S was preferred and both were mainly proceeding decomposition and partial oxidation.SO_(2)was formed at oxidation section together with obvious presence of H2 and CO.However,H2 and CO were inclined to be sustained under fuel rich condition in the complex reaction section.Reducing ER and increasing CH4/AG contributed to higher temperature,H_(2)S and CH_(4)oxidation and CO_(2)reactivity.Hence a growing trend for CH_(4)and AG to convert into H_(2),CO and SO_(2)could be witnessed.And this factor enhanced the generation of CS2 and COS in the flame inner core by interactions of CH4 and CO_(2)with sulfur species.COS was formed through the interactions of CO and CO_(2)with sulfur species.The CS_(2)production directly relied on reaction of CH_(4)with sulfur species.The concentration of COS was greater than CS_(2)since CS_(2)was probably inhibited due to the presence of H_(2).COS and CS_(2)could be consumed by further oxidation or other complex reactions.

关键词： Acid gas Methane Oxy-fuel combustion Oxidation Chemical analysis Carbon sulfides

Notoginsenoside Ft1 inhibits colorectal cancer growth by increasing CD8^(+)T cell proportion in tumor-bearing mice through the USP9X signaling pathway

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Chinese Journal of Natural Medicines 2024年第4期22卷 329-340页

作者： FenG Yutao LI Yuan MA Fen wu enjiang CHenG Zewei ZHOU Shiling WANG Zhengtao YANG Li SUN xun ZHANG Jiwei Shanghai Key Laboratory of Compound Chinese Medicines The MOE Key Laboratory for Standardization of Chinese MedicinesInstitute of Chinese Materia MedicaShanghai University of Traditional Chinese MedicineShanghai 201203China Gastrointestinal surgery Longhua HospitalShanghai University of Traditional Chinese MedicineShanghai 200032China

The management of colorectal cancer(CRC)poses a significant challenge,necessitating the development of innovative and effective therapeutics.Our research has shown that notoginsenoside Ft1(Ng-Ft1),a small molecule,markedly inhibits subcutaneous tumor formation in CRC and enhances the proportion of CD8^(+)T cells in tumor-bearing mice,thus restraining tumor growth.Investigation into the mechanism revealed that Ng-Ft1 selectively targets the deubiquitination enzyme USP9X,undermining its role in shieldingβ-catenin.This leads to a reduction in the expression of downstream effectors in the Wnt signaling pathway.These findings indicate that Ng-Ft1 could be a promising small-molecule treatment for CRC,working by blocking tumor progression via the Wnt signaling pathway and augmenting CD8^(+)T cell prevalence within the tumor environment.

关键词： Notoginsenoside Ft1 Colorectal cancer CD8^(+)T cell Ubiquitin-specific peptidase 9 X-linked β-Catenin Wnt