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Unraveling the relationship between Sr stoichiometry in Sr_(x)Fe_(1.5)Mo_(0.5)O_(6)-σ and its catalytic performance for high-temperature CO_(2) electrolysis

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Materials Reports(Energy) 2023年第1期3卷 86-92,I0003页

作者： Xiuan Xi Xiaoyu liu Lingui Huang jianwen liu Bo-Wen Zhang Gadi Rothenberg Xian-Zhu Fu Jing-Li Luo College of Materials Science and Engineering Shenzhen UniversityShenzhen518060China Department of Chemical and Materials Engineering University of AlbertaEdmontonABT6G 1H9Canada Van‘t Hoff Institute for Molecular Sciences University of AmsterdamScience Park 9041098XHAmsterdamthe Netherlands

The solid oxide electrolytic cell(SOEC)is one of the most promising energy conversion and storage devices,which could convert CO_(2) to CO with high Faradaic efficiency and production rate.However,the lack of active and stable cathode materials impedes their practical applications.Here we focus on the promising perovskite oxide cathode material Sr_(2)Fe_(1.5)Mo_(0.5)O_(6)-σ,with the aim of understanding how A-atom stoichiometry and catalytic performance are linked.We find that increasing the strontium content in the perovskite improves the chemisorption of CO_(2) on its surface,forming a SrCO_(3) phase.This hinders the charge transfer and oxygen exchange processes.Simulta-neously,strontoium segregation to the cathode surface facilitates coking of the surface during CO_(2) electrolysis,which poisons the electrode.Consequently,a small number of Sr deficiencies are optimal for both electrochemical performance and long-term stability.Our results provide new insights for designing high-performance CO_(2) electrolysis cathode materials.

关键词： SOECs Perovskite oxides Cathode Sr segregation CO_(2) electrolysis

稻虾共作模式下土壤甲烷产生与氧化潜力及其对温度的响应特征

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土壤学报 2024年第2期61卷 539-548页

作者：赵建婷方贤滔邹建文刘树伟江苏省低碳农业与温室气体减排重点实验室南京农业大学资源与环境科学学院南京210095

稻田是大气甲烷的重要人为排放源。为探讨不同稻田利用方式下甲烷产生和氧化潜力及其对温度的响应特征,以我国东南部地区常规稻田种植体系、由稻田转变来的稻虾种养结合体系和常规虾塘养殖体系为研究对象,分别采集位于江苏省句容市常规... 详细信息

稻田是大气甲烷的重要人为排放源。为探讨不同稻田利用方式下甲烷产生和氧化潜力及其对温度的响应特征,以我国东南部地区常规稻田种植体系、由稻田转变来的稻虾种养结合体系和常规虾塘养殖体系为研究对象,分别采集位于江苏省句容市常规稻田(CR)、共作稻区(R-CR)和共作虾区(R-CC)以及常规虾塘(CC)土壤样品,在5℃、15℃、25℃和35℃条件下进行为期30 d的室内培养实验。结果表明:农业土地利用方式转变对甲烷产生和氧化潜力均有显著影响,甲烷产生潜力由大到小依次为:共作虾区、常规虾塘、共作稻区、常规稻田,分别为1.14、0.33、0.25和0.17μg·g^(-1)·d^(-1),甲烷氧化潜力从大到小依次为:常规稻田、常规虾塘、共作稻区、共作虾区,分别为1.38、1.01、1.00和0.71μg·g^(-1)·d^(-1)。由于水分管理差异以及饲料、氮肥投入导致底物和环境因子差异造成了产甲烷菌、甲烷氧化菌的活性差异,使得不同土地利用类型土壤呈现不同的甲烷产生和氧化潜力特征;甲烷产生潜力随培养温度的升高呈指数增长,在5℃、15℃、25℃和35℃时的平均值分别为0.13、0.26、0.55和0.95μg·g^(-1)·d^(-1)。而甲烷氧化潜力仅在低温时比较敏感,在15℃、25℃、35℃时与5℃下的甲烷氧化潜力存在显著差异,而三种培养温度之间无显著差异(甲烷氧化潜力在5℃、15℃、25℃和35℃时分别为0.71、1.14、1.14和1.11μg·g^(-1)·d^(-1))。总体上,甲烷产生潜力对温度的响应强于甲烷氧化潜力。此外,土壤甲烷产生和氧化潜力均受温度或土地利用类型单因素的显著影响(P<0.01),但两者的交互效应仅对土壤甲烷产生潜力存在显著影响,对甲烷氧化潜力并无显著影响。

关键词：甲烷产生潜力氧化潜力温度农业生产方式转变

The ALMA-QUARKS Survey. Ⅱ. The ACA 1.3 mm Continuum Source Catalog and the Assembly of Dense Gas in Massive Star-Forming Clumps

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Research in Astronomy and Astrophysics 2024年第6期 121-141页

作者：许峰玮 Ke Wang Tie liu Lei Zhu Guido Garay Xunchuan liu Paul Goldsmith Qizhou Zhang Patricio Sanhueza Shengli Qin Jinhua He Mika Juvela Anandmayee Tej Hongli liu Shanghuo Li Kaho Morii Siju Zhang jianwen Zhou Amelia Stutz Neal J.Evans Kee-Tae Kim Shengyuan liu Diego Mardones Guangxing Li Leonardo Bronfman Ken'ichi Tatematsu Chang Won Lee Xing Lu Xiaofeng Mai Sihan Jiao James O.Chibueze Keyun Su Viktor L.Tóth School of Physics and Astronomy Yunnan University Yunnan Observatories Chinese Academy of Sciences Department of Physics University of Helsinki Indian Institute of Space Science and Technology Max Planck Institute for Astronomy Department of Astronomy Graduate School of Science The University of Tokyo Max-Planck-Institut für Radioastronomie Departamento de Astronom'?a Universidad de Concepcion Department of Astronomy The University of Texas at Austin Korea Astronomy and Space Science Institute Kavli Institute for Astronomy and Astrophysics Peking University Institute of Astronomy and Astrophysics Academia Sinica South-Western Institute for Astronomy Research Yunnan University University of Science and Technology National Astronomical Observatories Chinese Academy of Sciences Department of Mathematical Sciences University of South Africa Centre for Space Research Physics Department North-West University Department of Physics and Astronomy Faculty of Physical Sciences University of Nigeria Institute of Physics and Astronomy E?tv?s Lorànd University University of Debrecen Faculty of Science and Technology Department of Astronomy School of Physics Peking University Shanghai Astronomical Observatory Chinese Academy of Sciences Chinese Academy of Sciences South America Center for Astronomy National Astronomical Observatories Chinese Academy of Sciences Departamento de Astronomía Universidad de Chile Jet Propulsion Laboratory California Institute of Technology Center for Astrophysics | Harvard & Smithsonian National Astronomical Observatory of Japan National Institutes of Natural Sciences Astronomical Science Program The Graduate University for Advanced Studies

Leveraging the high resolution, sensitivity, and wide frequency coverage of the Atacama Large Millimeter/submillimeter Array（ALMA）, the QUARKS survey, standing for “Querying Underlying mechanisms of massive star formation with ALMA-Resolved gas Kinematics and Structures”, is observing 139 massive starforming clumps at ALMA Band 6（λ～1.3 mm）. This paper introduces the Atacama Compact Array（ACA） 7 m data of the QUARKS survey, describing the ACA observations and data reduction. Combining multiwavelength data, we provide the first edition of QUARKS atlas, offering insights into the multiscale and multiphase interstellar medium in high-mass star formation. The ACA 1.3 mm catalog includes 207 continuum sources that are called ACA sources. Their gas kinetic temperatures are estimated using three formaldehyde transitions with a non-LTE radiation transfer model, and the mass and density are derived from a dust emission model. The ACA sources are massive（16–84 percentile values of 6–160 M⊙）, gravity-dominated(M ∝ R1.1)fragments within massive clumps, with supersonic turbulence（M >1） and embedded star-forming protoclusters. We find a linear correlation between the masses of the fragments and the massive clumps,with a ratio of 6% between the two. When considering fragments as representative of dense gas, the ratio indicates a dense gas fraction（DGF） of 6%, although with a wide scatter ranging from 1% to 10%. If we consider the QUARKS massive clumps to be what is observed at various scales, then the size-independent DGF indicates a self-similar fragmentation or collapsing mode in protocluster formation. With the ACA data over four orders of magnitude of luminosity-to-mass ratio（L/M）, we find that the DGF increases significantly with L/M, which indicates clump evolutionary stage. We observed a limited fragmentation at the subclump scale,which can be explained by a dynamic global collapse process.

关键词：

The ALMA-QUARKS Survey.Ⅰ.Survey Description and Data Reduction

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Research in Astronomy and Astrophysics 2024年第2期24卷 104-124页

作者：刘训川 Tie liu Lei Zhu Guido Garay Hong-Li liu Paul Goldsmith Neal Evans Kee-Tae Kim Sheng-Yuan liu Fengwei Xu Xing Lu Anandmayee Tej Xiaofeng Mai Leonardo Bronfman Shanghuo Li Diego Mardones Amelia Stutz Ken'ichi Tatematsu Ke Wang Qizhou Zhang Sheng-Li Qin jianwen Zhou Qiuyi Luo Siju Zhang Yu Cheng Jinhua He Qilao Gu Ziyang Li Zhenying Zhang Suinan Zhang Anindya Saha Lokesh Dewangan Patricio Sanhueza Zhiqiang Shen Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Departamento de Astronomía Universidad de ChileLas Condes7591245 SantiagoChile School of Physics and Astronomy Yunnan UniversityKunming 650091China Jet Propulsion Laboratory California Institute of Technology4800 Oak Grove DrivePasadena CA 91109USA Department of Astronomy The University of Texas at AustinTX 78712-1205USA Korea Astronomy and Space Science Institute 776 Daedeokdae-roYuseong-guDaejeon 34055Republic of Korea Institute of Astronomy and Astrophysics Academia SinicaRoosevelt RoadTaipei 10617China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Department of Astronomy School of PhysicsPeking UniversityBeijing 100871China Indian Institute of Space Science and Technology Thiruvananthapuram 695547KeralaIndia Max Planck Institute for Astronomy Königstuhl 17D-69117 HeidelbergGermany Departamento de Astronomía Universidad de ConcepciónCasilla 160-CConcepciónChile Nobeyama Radio Observatory National Astronomical Observatory of JapanNational Institutes of Natural Sciences462-2 NobeyamaMinamimakiMinamisakuNagano 384-1305Japan Center for Astrophysics∣Harvard&Smithsonian 60 Garden StreetCambridgeMA 02138USA Max-Planck-Institut für Radioastronomie Auf dem Hügel 69D-53125 BonnGermany School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China National Astronomical Observatory of Japan 2-21-1 OsawaMitakaTokyo181-8588Japan Yunnan Observatories Chinese Academy of SciencesKunming 650216China Physical Research Laboratory NavrangpuraAhmedabad-380009India Astronomical Science Program The Graduate University for Advanced StudiesSOKENDAI2-21-1 OsawaMitakaTokyo 181-8588Japan University of Science and Technology Korea(UST)217 Gajeong-roYuseong-guDaejeon 34113Republic o

This paper presents an overview of the QUARKS survey,which stands for Querying Underlying mechanisms of massive star formation with ALMA-Resolved gas Kinematics and Structures."The QUARKS survey is observing139 massive clumps covered by 156 pointings at Atacama Large Millimeter/submillimeter Array(ALMA)Band 6(λ~1.3 mm).In conjunction with data obtained from the ALMA-ATOMS survey at Band 3(λ~3 mm),QUARKS aims to carry out an unbiased statistical investigation of massive star formation process within protoclusters down to a scale of 1000 au.This overview paper describes the observations and data reduction of the QUARKS survey,and gives a first look at an exemplar source,the mini-starburst Sgr B2(M).The wide-b and width(7.5 GHz)and high-angular-resolution(~0."3)observations of the QUARKS survey allow for the resolution of much more compact cores than those could be done by the ATOMS survey,and to detect previously unrevealed fainter filamentary structures.The spectral windows cover transitions of species including CO,SO,N_(2)D^(+),SiO,H_(30)α,H_(2)CO,CH_(3)CN,and many other complex organic molecules,tracing gas components with different temperatures and spatial extents.QUARKS aims to deepen our understanding of several scientific topics of massive star formation,such as the mass transport within protoclusters by(hub-)filamentary structures,the existence of massive starless cores,the physical and chemical properties of dense cores within protoclusters,and the feedback from already formed high-mass young protostars.

关键词： stars formation-stars kinematics and dynamics-ISM clouds-ISM molecules

In situ redox growth of mesoporous Pd-Cu2O nanoheterostructures for improved glucose oxidation electrocatalysis

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Science Bulletin 2019年第11期64卷 764-773页

作者： Ying Guo jianwen liu Yi-Tao Xu Bo Zhao Xuewan Wang Xian-Zhu Fu Rong Sun Ching-Ping Wong Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences. Shenzhen 518055China Department of Materials Science and Engineering City University of Hong KongHong KongChina College of Materials Science and Engineering Shenzhen UniversityShenzhen 518055China National Supercomputing Center in Shenzhen Shenzhen 518055China Department of Electronics Engineering The Chinese University of Hong KongHong KongChina School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

Interfaces of metal-oxide heterostructured electrocatalyst are critical to their catalytic activities due to the significant interfacial effects. However, there are still obscurities in the essence of interfacial effects caused by crystalline defects and mismatch of electronic structure at metal-oxide nanojunctions. To deeply understand the interfacial effects, we engineered crystalline-defect Pd-Cu2O interfaces through nonepitaxial growth by a facile redox route. The Pd-Cu2O nanoheterostructures exhibit much higher electrocatalytic activity toward glucose oxidation than their single counterparts and their physical mixture,which makes it have a promising potential for practical application of glucose biosensors.Experimental study and density functional theory(DFT) calculations demonstrated that the interfacial electron accumulation and the shifting up of d bands center of Cu-Pd toward the Fermi level were responsible for excellent electrocatalytic activity. Further study found that Pd(3 1 0) facets exert a strong metaloxide interface interaction with Cu2O(1 1 1) facets due to their lattice mismatch. This leads to the sinking of O atoms and protruding of Cu atoms of Cu2O, and the Pd crystalline defects, further resulting in electron accumulation at the interface and the shifting up of d bands center of Cu-Pd, which is different from previously reported charge transfer between the interfaces. Our findings could contribute to design and development of advanced metal-oxide heterostructured electrocatalysts.

关键词： Metal-oxide interfaces Crystalline defects Interfacial electron accumulation Electrocatalysts Density functional theory

粉细砂地层双线盾构施工实测地表沉降规律分析与预测

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土木与环境工程学报（中英文） 2024年第2期46卷 79-88页

作者：廖赵胜相龙胜高顺宇丁建文刘慧刚东南大学交通学院南京211189 中交隧道工程局有限公司南京分公司南京210000

依托南通地铁二号线某区间盾构隧道施工,针对盾构穿越典型粉细砂地层条件,对双线盾构隧道施工引起的地表沉降开展现场测试和规律分析,对经典Peck公式在南通地区粉细砂地层中双线盾构施工的适用性进行探讨,并研究先行线和后行线土体损失... 详细信息

依托南通地铁二号线某区间盾构隧道施工,针对盾构穿越典型粉细砂地层条件,对双线盾构隧道施工引起的地表沉降开展现场测试和规律分析,对经典Peck公式在南通地区粉细砂地层中双线盾构施工的适用性进行探讨,并研究先行线和后行线土体损失率和地表沉降槽宽度系数的取值及影响因素。研究结果表明,在粉细砂地层中,后行线隧道施工对地层的二次扰动效应会引起先行线轴线上方地表沉降的显著增加,且二次扰动效应明显强于其他软土地层,但弱于砂土地层;相较于淤泥质土地层,在粉细砂地层中盾构停机对地表沉降的影响更为显著;先行线和后行线施工引起土体损失率比值η_(1)/η_(2)在1~5倍范围内,平均值为2.3,先行线和后行线地表沉降槽宽度系数比值K_(1)/K_(2)在1~2倍范围内,平均值为1.4;砂土、粉细砂和粉土地层中土体损失率比值η_(1)/η_(2)均大于1,η_(1)/η_(2)和K_(1)/K_(2)与隧道覆土深度比(H/D)相关性较弱。

关键词：粉细砂地层双线盾构地表沉降土体损失率沉降槽宽度系数

盾构隧道施工对邻近建筑物差异沉降与扭曲变形影响分析

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防灾减灾工程学报 2024年第2期44卷 459-466,477页

作者：孙帅常连翠张煌丁建文刘晋余东南大学交通学院江苏南京210096 山东省嘉祥县住房和城乡建设局山东济宁272400

针对盾构隧道施工侧穿既有建筑物问题,结合南京地铁一号线北延段工程,以盾构隧道侧穿某浅基础建筑物为研究对象,通过对建筑物沉降实测数据进行分析,并利用Plaxis 3D软件建立数值模型,研究了隧道距建筑物不同水平距离和盾构以不同角度穿... 详细信息

针对盾构隧道施工侧穿既有建筑物问题,结合南京地铁一号线北延段工程,以盾构隧道侧穿某浅基础建筑物为研究对象,通过对建筑物沉降实测数据进行分析,并利用Plaxis 3D软件建立数值模型,研究了隧道距建筑物不同水平距离和盾构以不同角度穿越对建筑物差异沉降与扭曲变形特征的影响。结果表明:随着盾构开挖面逐渐接近建筑物,建筑物差异沉降及扭曲变形逐渐增大;差异沉降量在盾构机通过时达到最大值,之后趋于稳定,而扭曲变形峰值出现在盾构开挖面到达建筑物中点截面位置时,随后逐渐减小;当建筑物中心至隧道轴线的水平距离与隧道外径之比L/D=0.5~2时,建筑物差异沉降量较大,在L/D=1.5时达到峰值;当盾构穿越夹角从θ=0°增大至θ=90°时,建筑物最大差异沉降量不断增加,而最终扭曲变形值则先增大后减小,在θ=45°时扭曲变形达到峰值。研究结果可为盾构隧道侧穿浅基础建筑物时相关类似工程提供参考。

关键词：盾构隧道浅基础建筑物差异沉降扭曲变形

小型高效气动立式预混装置异形桨叶工作特性研究

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固体火箭技术 2024年第2期47卷 246-252页

作者：刘江何文斌祁根山李丹付丽初众仇建文内蒙古工业大学机械工程学院呼和浩特010010 内蒙古航天红峡化工有限公司呼和浩特010010

为解决某交联剂在预混时溶解慢、易挥发、对操作人员危害大等问题,开发了一套采用单轴异形桨叶的可远程控制的小型高效立式气动预混装置。通过有限元方法计算了四种搅拌叶片的流场特性,分析了异形桨叶和其他三种常用桨叶的总体流型、速... 详细信息

为解决某交联剂在预混时溶解慢、易挥发、对操作人员危害大等问题,开发了一套采用单轴异形桨叶的可远程控制的小型高效立式气动预混装置。通过有限元方法计算了四种搅拌叶片的流场特性,分析了异形桨叶和其他三种常用桨叶的总体流型、速度流线分布。结果表明,在预混转速为45 rpm时,异形叶片可实现交联剂径向流动,使旋转中心的交联剂充分混合,有效防止中心死区的出现,展现出良好的预混性能,预混时间由人工预混的6 h缩短为2 h,乙腈溶液挥发量减少了60.8%,有效解决了交联剂挥发和挂壁析出问题,提高了交联剂的预混效率。

关键词：交联剂小型立式预混装置异形桨叶流场分析预混性能

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双钟形喷管在分离工作阶段的吸气阻力分析

火箭推进 2024年第2期50卷 88-97页

作者：刘亚洲曹晨胡海峰杨建文西安航天动力研究所液体火箭发动机技术重点实验室陕西西安710100

在低空工作阶段产生于回流区的吸气阻力对双钟形喷管的性能具有不可忽视的影响。采用仿真手段对不同设计参数的双钟形喷管的吸气阻力进行了研究,获得了其在不同飞行高度下的阻力系数。研究结果表明,吸气阻力并不总是如已有文献认为的随... 详细信息

在低空工作阶段产生于回流区的吸气阻力对双钟形喷管的性能具有不可忽视的影响。采用仿真手段对不同设计参数的双钟形喷管的吸气阻力进行了研究,获得了其在不同飞行高度下的阻力系数。研究结果表明,吸气阻力并不总是如已有文献认为的随飞行高度的增加而不断减小。延伸段顺压梯度分布的双钟形喷管的吸气阻力随飞行高度的增加不断减小;延伸段等压或逆压梯度分布的双钟形喷管的吸气阻力随飞行高度的增加呈现出先减小后增加的趋势,拐点出现在2 km处。该现象出现的原因在于,不同构型的双钟形喷管在0~8 km左右的分离工作阶段,回流区轴向尺寸和回流与大气间的压力差随飞行高度的变化趋势不同。此外,增加基础段长度和面积比、减小延伸段长度和面积比均有利于减小吸气阻力,阻力系数的减小幅度为1%~2%。

关键词：双钟形喷管吸气阻力流动分离马赫反射规则反射