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Unravelling the Anomalous Coking Resistance over Boron Nitride-Supported Ni Catalysts for Dry Reforming of Methane

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CCS Chemistry 2023年第9期5卷 2111-2124页

作者： Jiang Deng Min Gao Jun-ya Hasegawa Xiaoyu Zhang Aiyong Wang Aling Chen Dengsong Zhang International Joint Laboratory of Catalytic Chemistry College of SciencesShanghai UniversityShanghai 200444 Institute for Chemical Reaction Design and Discovery(wpi-ICReDD) Hokkaido UniversitySapporo 001-0021 Institute for Catalysis Hokkaido UniversitySapporo 001-0021

Metal oxides have been used as the supports for heterogeneous catalysis formany years,but they still suffer from coking in some high-temperature *** main reasons for coking are the uncontrollable dissociation of C-H and the overbalance between carbon deposition and ***,we find a boron nitride(BN)-immobilized Ni catalyst shows unprecedented coking resistance in dry reforming of methane via the incomplete decomposition of *** the Ni-based catalysts supported by traditional metal oxides,BN-supported Ni accelerates the first C-H dissociation while inhibiting the breaking of the final C-H bond;hence,the suppression of the complete decomposition of methane thoroughly addresses the coking *** work reveals the fundamental reason for the coking resistance over BN-supported Ni catalysts is selective activation of the C-H bond,which can provide an inspiring idea for other applications.

关键词： heterogenous catalysis boron nitrides dry reforming of methane coking resistance methane conversion

Chain-Length-Dependent Hydrogen-Bonded Self-Assembly of Terminally Functionalized Discrete Polyketones

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Precision Chemistry 2023年第1期1卷 34-39页

作者： Kilingaru I.Shivakumar Yumehiro Manabe Tomoki Yoneda Yuki Ide Yasuhide Inokuma Institute for Chemical Reaction Design and Discovery(wpi-ICReDD) Hokkaido UniversitySapporoHokkaido 001-0021Japan Division of Applied Chemistry Faculty of EngineeringHokkaido UniversitySapporoHokkaido 060-8628Japan

Here,we report the synthesis and the chain-lengthdependent self-assembling behaviors of discrete di-,tetra-,and hexaketones terminally functionalized with hydrogen-bonding carboxyl(C1,C2,and C3)and 3-acylaminopyridine groups(P1,P2,and P3).These polyketones were prepared by the coupling reactions of silylated analogues of 3,3-dimethylpentane-2,4-dione and t-butyl 2,2-dimethyl-3-oxobutanoate and the subsequent hydrolysis or amidation with ***-crystal Xray diffraction analysis revealed that C1 and C2 form helical assemblies in which the components are connected by the dimerization of terminal carboxyl groups,whereas the longer C3 showed infinite hydrogen-bonded chains mediated by 1,4-dioxane used as a crystallization ***-terminated P1 exhibited a three-dimensional hydrogen-bonded network owing to multiple NH…N(pyridine)hydrogen bonds in the solid state.P2 generated a double-helix-like fiber structure in the crystalline *** the pyridine-terminated polyketones P1−P3,only P2 showed gelation behavior in chloroform(100 mM concentration)at 25℃.The scanning electron microscopy measurement of xerogel P2 revealed the formation of rod-like structures with a thickness of approximately 0.5−3.5μ*** results demonstrate that the precise control of the polyketone chain length can significantly alter hydrogen-bonded self-assembly in the solid state and in solution even with the same terminal structures.

关键词： polyketone hydrogen bond helix self-assembly gel

Piezoresistive effect in MoO3 nanobelts and its application in strain-enhanced oxygen sensors

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Nano Research 2014年第2期7卷 180-189页

作者： Xiaonan Wen Weiqing Yang Yong Ding Simiao Niu Zhong Lin wang School of Material Science and Engineering Georgia Institute of Technology Atlanta Georgia 30332-0245 USA State Key Laboratory of Electronic Thin films and Integrated Devices University of Electronic Science and Technology of China Chengdu 610054 China Satellite Lab. MANA WPI National Institute of Materials Science Japan

MoO3 nanobelts （NBs） having different properties have been synthesized via a physical vapor deposition （PVD） method. The crystallographic structures and morphologies of the NBs were characterized by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. Electrical measurements were performed and the profound piezoresistive effect in MoO3 experimentally studied and verified. Factors that influence the gauge factor, such as NB size, doping concentration and atmosphere composition, are discussed and analyzed. Gas sensing performance was also tested in devices and it was demonstrated that by applying strain to the gas sensor, its sensing performance could be effectively tuned and enhanced. This study provides the first demonstration of significant piezoresistivity in MoO3 NBs and the first illustration of a generic mechanism by means of which this effect can be coupled with other electronic modulation measures to afford better device performance and broader material functionality.

关键词： molybdenum trioxide nanobelt piezoresistive effect oxygen sensor

Effect of mixing rate and temperature on primary Si phase of hypereutectic Al-20Si alloy during control ed diffusion solidification(CDS) process

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China Foundry 2015年第3期12卷 173-179页

作者： Yuan-dong Li Xin-long Zhang Ying Ma Diran Apelian Hong-wei Zhou Xing-hai Liu State Key Lab. of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology Key Lab. of Nonferrous Metal Alloys and Processing Ministry of Education Lanzhou University of Technology Metal Processing Institute WPIWorcester MA 01609 USA.

Controlled Diffusion Solidification(CDS) is a promising process relied on mixing two liquid alloys of precisely controlled chemistry and temperature in order to produce a predetermined alloy composition. In this study, the CDS was employed to prepare hypereutectic Al-20%Si(mass fraction) alloy using Al-30%Si and pure Al of different temperatures. The mixing rate was controlled using three small crucibles with a hole of different diameters in their bottom. The effect of mixing rate and temperature on the microstructure of the primary Si-phase during the mixing of molten Al and Al-30%Si was studied. The results showed that when the diameter of the small crucible bottom hole is 16 mm, a higher mass mixing rate 0.217 kg·s-1 would results in a lower stream velocity 0.414 m·s-1. Conversely a lower mass mixing rate 0.114 kg·s-1(the diameter of the small crucible bottom hole is 8 mm) would result in a higher fluid stream velocity 0.879 m·s-1. A lower mass mixing rate would be better to refine the primary Si than a higher mass mixing rate. Meanwhile, the morphology and distribution of primary Si could also be improved. Especially, when Al-30%Si alloy at 820 °C was mixed with pure Al at 670 °C in the case of a mass mixing rate of 0.114 kg·s-1 and a pouring temperature of 680 °C, the average size of the primary Si phase would be only 18.2 μm. Its morphology would mostly be octahedral and the primary Si would distribute uniformly in the matrix microstructure. The lower mass mixing rate(0.114 kg·s-1) will enhance the broken tendency of Al-30%Si steam and the mixing agitation of resultant melt, so the primary Si phase can be better refined.

关键词： Controlled Diffusion Solidification(CDS) hypereutectic Al-Si alloy mass mixing rate stream velocity primary Si

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应对热电材料人工智能领域的大数据挑战

Science China Materials 2024年第4期67卷 1173-1182页

作者：贾雪 Alex Aziz Yusuke Hashimoto 李昊 Advanced Institute for Materials Research(wpi-AIMR) Tohoku UniversitySendai 980-8577Japan Tohoku Forum for Creativity Tohoku UniversitySendai 980-8577Japan

人工智能的发展正在改变材料科学领域.然而,大规模材料数据集中存在错误数据以及利用机器学习预测与温度相关的性质时出现过拟合等挑战.本文以热电材料为例,首先采取一系列合理的方法删除问题数据,从Starrydata2数据库中获得包括7295种... 详细信息

人工智能的发展正在改变材料科学领域.然而,大规模材料数据集中存在错误数据以及利用机器学习预测与温度相关的性质时出现过拟合等挑战.本文以热电材料为例,首先采取一系列合理的方法删除问题数据,从Starrydata2数据库中获得包括7295种成分在不同温度下的92,291个数据.然后,提出了一种基于成分的交叉验证方法避免过拟合.进而,使用梯度提升决策树方法构建了机器学习模型,并获得了显著的R2.最后,使用该模型对Materials Project数据库中的材料进行评估,Ge2Te5As2和Ge3(Te3As)2表现出较高的zT值.理论计算得到n型和p型Ge2Te5As2的最大zT值为1.98和2.12,n型和p型Ge3(Te3As)2的最大zT值为0.58和0.74,表明它们是有潜力的热电材料.本工作提出了一个处理和克服材料科学中的人工智能大数据挑战的示例.

关键词：人工智能大数据机器学习过拟合热电材料材料数据数据库温度相关

The CatMath: an online predictive platform for thermal + electrocatalysis

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Frontiers of Chemical Science and Engineering 2023年第12期17卷 2156-2160页

作者： Heng Liu Hao Zheng Zhenhe Jia Binghui Zhou Yan Liu Xuelu Chen Yajun Feng Li Wei Weijie Yang Hao Li Advanced Institute for Materials Research(wpi-AIMR) Tohoku UniversitySendai 980-8577Japan Department of Power Engineering School of EnergyPower and Mechanical EngineeringNorth China Electric Power UniversityBaoding 071003China School of Chemical and Biomolecule Engineering The University of SydneySydney NSW 2006Australia

The catalytic volcano activity models are the quantified and visualized tools of the Sabatier principle for heterogeneous catalysis, which can depict the intrinsic activity optima and trends of a catalytic reaction as a function of the reaction descriptors, i.e., the bonding strengths of key reaction species. These models can be derived by microkinetic modeling and/or free energy changes in combination with the scaling relations among the reaction intermediates. Herein, we introduce the CatMath—an online platform for generating a variety of common and industrially important thermal + electrocatalysis. With the CatMath, users can request the volcano models for available reactions and analyze their materials of interests as potential catalysts. Besides, the CatMath provides the function of the online generation of Surface Pourbaix Diagram for surface state analysis under electrocatalytic conditions, which is an essential step before analyzing the activity of an electrocatalytic surface. All the model generation and analysis processes are realized by cloud computing via a user-friendly interface.

关键词： CatMath catalysis volcano activity plots Surface Pourbaix Diagrams online platform

利用探针跳跃式扫描离子电导显微镜技术揭示结直肠癌单细胞层面对H_(2)O_(2)良性应激的动态响应

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Science Bulletin 2024年第12期69卷 1909-1919页

作者：王东 Emily Woodcock 杨羲 Hiromi Nishikawa Elena V.Sviderskaya Masanobu Oshima Christopher Edwards 张彦军 Yuri Korchev wpi Nano Life Science Institute(wpi-Nano LSI) Kanazawa UniversityKanazawa 920-1192Japan Department of Medicine Imperial College LondonLondon W120NNUnited Kingdom Cell Biology Research Centre Molecular and Clinical Sciences Research InstituteSt George’sUniversity of LondonLondon SW170REUnited Kingdom

Colorectal cancer(CRC),a widespread malignancy,is closely associated with tumor microenvironmental hydrogen peroxide(H_(2)O_(2))*** clinical trials targeting H_(2)O_(2)for cancer treatment have revealed its paradoxical role as a promoter of cancer *** the dynamics of cancer cell H_(2)O_(2)eustress at the single–cell level is *** this study,non–contact hopping probe mode scanning ion conductance microscopy(HPICM)with high-sensitive Pt–functionalized nanoelectrodes was employed to measure dynamic extracellular to intracellular H_(2)O_(2)gradients in individual colorectal cancer Caco–*** explored the relationship between cellular mechanical properties and H_(2)O_(2)*** to 0.1 or 1 mmol/L H_(2)O_(2)eustress increased the extracellular to intracellular H_(2)O_(2)gradient from 0.3 to 1.91 or 3.04,***,cellular F–actin–dependent stiffness increased at 0.1 mmol/L but decreased at 1 mmol/L H_(2)O_(2)*** H_(2)O_(2)–induced stiffness modulated AKT activation positively and glutathione peroxidase 2(GPX2)expression *** findings unveil the failure of some H_(2)O_(2)-targeted therapies due to their ineffectiveness in generating H_(2)O_(2),which instead acts eustress to promote cancer cell *** research also reveals the complex interplay between physical properties and biochemical signaling in cancer cells'antioxidant defense,illuminating the exploitation of H_(2)O_(2)eustress for survival at the single–cell *** GPX and/or catalase(CAT)enhances the cytotoxic activity of H_(2)O_(2)eustress against CRC cells,which holds significant promise for developing innovative therapies targeting cancer and other H_(2)O_(2)-related inflammatory diseases.

关键词： SPM Nanoprobe Nanobiology SECM ROS Stiffness

Microcrystallization and lattice contraction of NiFe LDHs for enhancing water electrocatalytic oxidation

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Carbon Energy 2022年第5期4卷 901-913页

作者： Zhicheng Zheng Dan Wu Gen Chen Ning Zhang Hao Wan Xiaohe Liu Renzhi Ma State Key Laboratory of Powder Metallurgy School of Materials Science and EngineeringCentral South UniversityChangshaHunanPR China School of Chemical Engineering Zhengzhou UniversityZhengzhouHenanPR China International Center for Materials Nanoarchitectonics(wpi-MANA) National Institute for Materials Science(NIMS)IbarakiJapan

The lattice-oxygen-mediated mechanism is considered as a reasonable mechanism for the electrochemical catalytic oxygen evolution reaction(OER)of NiFe layered double hydroxides(LDHs).A NiFe LDH with distinct lattice contraction and microcrystallization was synthesized via a simple one-step method using sodium *** lattice contraction is attributed to the interaction of carbon in sodium gluconate and iron in NiFe *** NiFe LDH with optimized microcrystallization and lattice contraction shows a low overpotential of 217 mV at a current density of 10 mA cm^(−2) and excellent durability of 20 h at a high current density of 100 mA cm^(−2).The results revealed that a contractive metal–oxygen bond could boost the intrinsic activity of active sites and the microcrystallization promotes an increase in the number of active sites in terms of unit *** chemical environment of oxygen elemental characterization and resistance at different chronopotentiometry times confirm that the lattice oxygen element is indeed involved in the process of OER,supporting the lattice-oxygen-mediated mechanism of NiFe *** functional theory calculations reveal that contractive metal–oxygen bonds induced a reduction of the adsorption energy barrier of intermediate products,thus improving the intrinsic catalytic *** special characteristics of microcrystallization and lattice contraction of NiFe LDH provide a strategy to improve both the number and the intrinsic activity of active sites in a versatile manner.

关键词： lattice contraction lattice-oxygen-mediated mechanism microcrystallization NiFe LDH oxygen evolution reaction

The mass of our Milky Way

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Science China(Physics,Mechanics & Astronomy) 2020年第10期63卷 1-46页

作者： WenTing Wang JiaXin Han Marius Cautun ZhaoZhou Li Miho N.Ishigaki Department of Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Kavli IPMU(wpi) UTIASThe University of TokyoKashiwaChiba 277-8583Japan Leiden Observatory Leiden UniversityPO Box 9513NL-2300 RA Leidenthe Netherlands Astronomical Institute Tohoku UniversityAoba-kuSendaiMiyagi 980-8578Japan

We perform an extensive review of the numerous studies and methods used to determine the total mass of the Milky *** group the various studies into seven broad classes according to their modeling *** classes include:i)estimating Galactic escape velocity using high velocity objects;ii)measuring the rotation curve through terminal and circular velocities;iii)modeling halo stars,globular clusters and satellite galaxies with the spherical Jeans equation and iv)with phase-space distribution functions;v)simulating and modeling the dynamics of stellar streams and their progenitors;vi)modeling the motion of the Milky Way,M31 and other distant satellites under the framework of Local Group timing argument;and vii)measurements made by linking the brightest Galactic satellites to their counterparts in *** each class of methods,we introduce their theoretical and observational background,the method itself,the sample of available tracer objects,model assumptions,uncertainties,limits and the corresponding measurements that have been achieved in the *** the measured total masses within the radial range probed by tracer objects and the extrapolated virial masses are discussed and *** also discuss the role of modern numerical simulations in terms of helping to validate model assumptions,understanding systematic uncertainties and calibrating the *** measurements in the last two decades show a factor of two scatters,recent measurements using Gaia DR2 data are approaching a higher *** end with a detailed discussion of future developments in the field,especially as the size and quality of the observational data will increase tremendously with current and future *** such cases,the systematic uncertainties will be dominant and thus will necessitate a much more rigorous testing and characterization of the various mass determination methods.

关键词： Milky Way dark matter stellar halo dynamics satellite galaxies