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还原温度与时间对铁基催化剂浆态床F-T合成性能的影响(英文)

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燃料化学学报 2005年第5期33卷 590-596页

作者：郝庆兰白亮郝栩相宏伟李永旺易凡徐斌富中国科学院山西煤炭化学研究所煤转化国家重点实验室山西太原030001 中国科学院研究生院武汉大学物理系湖北武汉430072

在浆态床反应器中考察了未还原催化剂以及在240℃和270℃的还原温度下还原时间对Fe/Cu/K/SiO2催化剂F-T合成反应性能的影响,采用M ssbauer谱研究了还原和反应后催化剂的物相组成。结果表明,在240℃延长还原时间或将还原温度升高到270℃... 详细信息

在浆态床反应器中考察了未还原催化剂以及在240℃和270℃的还原温度下还原时间对Fe/Cu/K/SiO2催化剂F-T合成反应性能的影响,采用M ssbauer谱研究了还原和反应后催化剂的物相组成。结果表明,在240℃延长还原时间或将还原温度升高到270℃均有利于催化剂的还原,270℃还原的催化剂的活性和稳定性明显高于未还原和240℃还原的催化剂,催化剂的运行稳定性与催化剂在反应过程中的流失量有密切关系。催化剂高温还原时烃产物分布倾向于生成低碳数的烃类,在相同的还原温度下,烃产物选择性随还原时间的延长向轻组分方向偏移。

关键词： F—T合成还原温度还原时间浆态床反应器铁基催化剂喷雾干燥

On the Energy Budget of Starquake-induced Repeating Fast Radio Bursts

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Research in Astronomy and Astrophysics 2024年第10期24卷 180-188页

作者： Wei-Yang Wang Chen Zhang Enping Zhou Xiaohui Liu Jiarui Niu Zixuan Zhou He Gao Jifeng Liu renxin xu Bing Zhang school of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China state key laboratory of Nuclear {3. and technology School of PhysicsPeking UniversityBeijing 100871China The HKUST Jockey Club Institute for Advanced Study The Hong Kong University of Science and TechnologyHong KongChina school of physics Huazhong University of Science and TechnologyWuhan 430074China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China school of Mathematics and physics University of Science and TechnologyBeijing 100083China Department of Astronomy Beijing Normal UniversityBeijing 100875China New Cornerstone Science laboratory National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Nevada Center for Astrophysics University of NevadaLas VegasNV 89154USA Department of physics and Astronomy University of NevadaLas VegasNV 89154USA

With a growing sample of fast radio bursts(FRBs),we investigate the energy budget of different power sources within the framework of magnetar starquake triggering *** a starquake,the energy can be released in any form through strain,magnetic,rotational,and gravitational *** strain energy can be converted from three other kinds of energy during *** following findings are revealed:(1)The crust can store free magnetic energy of~10^(46)erg by existing toroidal fields,sustaining 10^(6)bursts with frequent starquakes occurring due to crustal instability.(2)The strain energy develops as a rigid object spins down,which can be released during a global starquake accompanied by a ***,it takes a long time to accumulate enough strain energy via spindown.(3.The rotational energy of a magnetar with P■0.1 s can match the energy and luminosity budget of FRBs.(4)The budget of the total gravitational energy is high,but the mechanism and efficiency of converting this energy to radiation deserve further exploration.

关键词： stars:magnetars stars:neutron radiation mechanisms:non-thermal

Growth of Noncentrosymmetric Two-Dimensional Single Crystals

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Precision Chemistry 2024年第7期2卷 330-354页

作者： Guoliang Cui Jiajie Qi Zhihua liang Fankai Zeng Xiaowen Zhang Xiaozhi xu Kaihui Liu Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum MaterialsSchool of PhysicsSouth China Normal UniversityGuangzhou 510631China Guangdong−Hong Kong Joint laboratory of Quantum Matter Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510631China state key laboratory for Mesoscopic {3. Frontiers Science Center for Nano-optoelectronicsSchool of PhysicsPeking UniversityBeijing 100871China Songshan Lake Materials laboratory Institute of PhysicsChinese Academy of SciencesDongguan 523820China

Among the various two-dimensional(2D)materials,more than 99%of them are ***,since the commonly used substrates are generally centrosymmetric,antiparallel islands are usually inevitable in the growth of noncentrosymmetric 2D materials because of the energetic equivalency of these two kinds of antiparallel islands on centrosymmetric ***,achieving the growth of noncentrosymmetric 2D single crystals has long been a great challenge compared with the centrosymmetric ones like *** this review,we presented the remarkable efforts and progress in the past decade,through precise chemical *** first discussed the great challenge and possible strategies in the growth of noncentrosymmetric 2D single ***,we focused on the advancements made in producing representative noncentrosymmetric 2D single crystals,including hexagonal boron nitride(hBN),transition metal dichalcogenides(TMDs),and other noncentrosymmetric 2D *** last,we summarized and looked forward to future research on the growth of layer-,stacking-,and twist-controlled noncentrosymmetric 2D single crystals and their heterostructures.

关键词： noncentrosymmetric two-dimensional materials single crystals hexagonal boron nitride transition metal dichalcogenides

Timing and Spectral Analysis of the Black Hole X-Ray Binary MAXI J1803.298 with Insight-HXMT Data

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Research in Astronomy and Astrophysics 2024年第6期24卷 209-224页

作者： Ying-Chen xu Jin-Lu Qu MMéndez Rui-Can Ma Long Ji liang Zhang Yue Huang Qing-Cui Bu Li-Ming Song key laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China university of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Kapteyn Astronomical Institute University of GroningenP.O.BOX 8009700 AV GroningenThe Netherlands Dongguan Neutron Science Center Dongguan 523808China school of physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China Institut für Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard Karls UniversitätSand 1D-72076 TübingenGermany

We present a comprehensive analysis of the 2021 outburst of MAXI J1803.298 utilizing observations of the Insight-Hard X-ray Modulation Telescope(Insight-HXMT)spanning from the low hard state to the high soft *** the Insight-HXMT data set,compared to the previous work,we identify a more prolonged presence of typeC quasi-periodic oscillations(QPOs)with centroid frequencies ranging from~0.16 to 6.3.Hz,which present correlations with the hardness ratio and the photon index of the Comptonized *** QPO frequencies less than~2 Hz,the QPO phase lags are hard(photons of 10–19 keV arrive later than those of 1–4 keV),while at higher frequencies,the lags become soft at and above~4 ***,the spectra in all Insight-HXMT observations consist of a multi-color blackbody component and a Comptonized component,as commonly observed in classical black hole X-ray *** analyze state transitions and the evolution of accretion geometry in this *** fitted inner disk radius increases abnormally during the low hard state,hypothesized to result from the corona condensing onto the inner ***,two significant drops in flux are observed during the soft intermediate state,maybe implying changes in the corona/jet and the disk,respectively.

关键词： X-rays:binaries accretion accretion disks stars:black holes

Electrocatalytic Reduction of CO_(2)to CO with Almost 100%Faradaic Efficiency Using Oxygen-Vacancy Enriched Two-Dimensional MgO

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CCS Chemistry 2024年第6期6卷 1477-1486页

作者： Yu Han Sunggi An Xinyu Zhan Leiduan Hao liang xu Song Hong Dongmin Park Yuxin Chen Yiwen xu Jiwen Zhao Xinyi Tan Alex W.Robertson Yousung Jung Zhenyu Sun state key laboratory of Organic-Inorganic Composites College of Chemical EngineeringBeijing University of Chemical TechnologyBeijing 100029 Department of Chemical and Biomolecular Engineering(BK21four) Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141 beijing key laboratory of Environmental Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081 Department of physics University of WarwickCoventry

The design and development of cheap,abundant,and efficient electrocatalysts for selective CO_(2)electroreduction is highly desirable yet remains an ongoing ***,we report on our discovery of the use of two-dimensional MgO rich in oxygen vacancies(VO)as an electrocatalyst for the efficient reduction of CO_(2)to yield CO in 1-butyl-3.methylimidazolium hexafluorophosphate dissolved in *** faradaic efficiency toward CO reaches as high as 99.6±0.24%with a current density of up to 40.8 mA cm−*** functional theory calculations illustrate that the introduction of VO in MgO substantially lowers the reaction-free energy for the transformation of ^(*)COO^(−) to ^(*)COOH,the potential determining step,which greatly boosts CO_(2)conversion *** work opens the way to realizing economic and efficient CO_(2)electrolysis of group II metals.

关键词： CO_(2)reduction electrocatalysis CO MgO ionic liquid oxygen-vacancy

Causal propagation of signals in strangeon matter

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Science china(physics,Mechanics & Astronomy) 2018年第8期61卷 82-88页

作者： JiGuang Lu EnPing Zhou XiaoYu Lai renxin xu CAS key laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China key laboratory of Radio Astronomy Chinese Academy of SciencesBeijing 100012China school of physics and state {3. laboratory of Nuclear Science and technology Peking UniversityBeijing 100871China school of physics and Mechanical&Electrical Engineering Hubei University of EducationWuhan 430205China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Kavil Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

The state equation for strangeon matter is very stiff due to the non-relativistic nature of its particles and their repulsive interaction, such that pulsar masses as high as ～ 3. would be expected. However, an adiabatic sound speed, cs = √P/ρ, is usually superluminal in strangeon matter, and the dynamic response of a strangeon star （e.g., binary merger） is not tractable in numerical simulations. In this study, we examined signal propagation in strangeon matter and calculate the actual propagation speed, Csignal. We found that the causality condition, Csignal 〈 c, is satisfied and the signal speed is presented as a function of stellar radius.

关键词： equations of state of neutron-star matter acoustic signal processing control theory

ATOVS卫星资料同化对三江源暴雨预报影响的试验研究

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大气科学学报 2024年第3期47卷 460-475页

作者：钟浩斌王磊李谢辉陈旭梁周彤成都信息工程大学大气科学学院四川成都610225 高原大气与环境四川省重点实验室四川成都610225 中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室北京100029

选取3.三江源的典型降水个例(2018年6月3.日、7月5日、8月24日),利用NCEP FNL再分析数据,并加入ATOVS湿度探测器MHS资料同化,基于WRF模式及其三维变分同化系统对三江源区域3.降水过程进行循环同化试验,分析3.事件的模拟状况,并定量... 详细信息

选取3.三江源的典型降水个例(2018年6月3.日、7月5日、8月24日),利用NCEP FNL再分析数据,并加入ATOVS湿度探测器MHS资料同化,基于WRF模式及其三维变分同化系统对三江源区域3.降水过程进行循环同化试验,分析3.事件的模拟状况,并定量分析降水结果。结果表明,3.降水事件在加入MHS资料同化后,1)模拟的水汽增大,在中层体现最明显且更符合实际情况,高空水汽和风模拟较好,地面温度预报欠佳;2)MHS资料对降水预报的影响主要体现在降水区面积和降水量的增大,提高了降水预报水平,但也带来较多空报区域;3.从TS、ETS、POD评分结果来看,有两个降水试验的提升较为明显,其中“063.”试验TS评分结果在0.5~10 mm之间提升了0.05~0.1,ETS在5 mm提升超过0.08,在10~20 mm之间也有少量提升,POD检验在0.5~20 mm之间均有提升,在0.5~10 mm之间提升最为明显,提升了0.1~0.25,“0824”试验TS与ETS在10~20 mm之间提升超过0.1,POD检验在6~20 mm之间提升了0.1~0.4,同化后降水预报有所改善,且在大阈值降水尤为明显;4)MHS资料同化对“0705”试验降水预报改善不明显,说明同化并不是每次都能给结果带来正效应,因此在使用MHS资料时不能过于信赖它,但总体上,同化MHS资料能够提升预报质量。

关键词：三江源降水 WRF模式资料同化微波辐射数据

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Compressive strain in Cu catalysts:Enhancing generation of C2+products in electrochemical CO_(2)reduction

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Science Bulletin 2024年第18期69卷 2881-2891页

作者： Qikui Fan Pengxu Yan Fuzhu Liu Zhongshuang xu Pengfei liang Xi Cao Chenliang Ye Moxuan Liu Lingyi Zhao Shan Ren Huanran Miao Xiai Zhang Zhimao Yang Xiangdong Ding Jian Yang Chuncai Kong Yuen Wu MOE key laboratory for Non-Equilibrium Synthesis and Modulation of Condensed Matter Key Laboratory for Advanced Materials and Mesoscopic Physics of Shaanxi ProvinceSchool of PhysicsXi’an Jiaotong UniversityXi’an 710049China state key laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China College of Chemistry and Materials Science Anhui Normal UniversityWuhu 241002China Department of Power Engineering North China Electric Power UniversityBeijing 102206China College of Chemistry and Chemical Engineering Xi’an University of Science and TechnologyXi’an 710054China Center for Materials and Interfaces Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Hefei National laboratory for Physical Sciences at the Microscale Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)School of Chemistry and Materials Scienceand National Synchrotron Radiation LaboratoryUniversity of Science and Technology of ChinaHefei 230026China

Elastic strain in Cu catalysts enhances their selectivity for the electrochemical CO_(2)reduction reaction(eCO_(2)RR),particularly toward the formation of multicarbon(C_(2+))***,the reasons for this selectivity and the effect of catalyst precursors have not yet been ***,we employed a redox strategy to induce strain on the surface of Cu *** transformation was employed to convert Cu nanocrystals to CuxO nanocrystals;these were subsequently electrochemically reduced to form Cu catalysts,while maintaining their compressive *** a flow cell configuration,a current density of 1 A/cm^(2)and Faradaic efficiency exceeding 80%were realized for the C_(2+)*** selectivity ratio of C_(2+)/C1 was also remarkable at 9.9,surpassing that observed for the Cu catalyst under tensile strain by approximately 7.6 ***-situ Raman and infrared spectroscopy revealed a decrease in the coverage of K+ion-hydrated water(K·H_(2)O)on the compressively strained Cu catalysts,consistent with molecular dynamics simulations and density functional theory *** element method simulations confirmed that reducing the coverage of coordinated K·H_(2)O water increased the probability of intermediate reactants interacting with the surface,thereby promoting efficient C–C coupling and enhancing the yield of C_(2+)*** findings provide valuable insights into targeted design strategies for Cu catalysts used in the eCO_(2)RR.

关键词： Strain effect CO_(2)electroreduction to C^(2+) Catalytic selectivity Copper catalyst Water coverage

铋纳米颗粒负载的氮掺杂石墨毡用于稳定高效的铁铬液流电池

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新型炭材料（中英文） 2024年第1期39卷 131-141页

作者：车航欣高宇飞杨家辉洪崧郝磊端徐亮 Sana Taimoor Alex WRobertson 孙振宇北京化工大学化学工程学院有机-无机复合材料国家重点实验室北京100000 桂林电子科技大学机电工程学院广西桂林541000 Department of physics University of WarwickCoventry CV47ALUK

铁铬氧化还原液流电池(ICRFB)是一种具有成本效益的可规模化储能系统,其利用资源丰富、低成本的铬和铁作为电解液的活性物质。然而,ICRFB存在Cr^(3.)/Cr^(2+)电化学活性低、负极易产生严重的析氢反应(HER)等问题。本文报道了一种简单的... 详细信息

铁铬氧化还原液流电池(ICRFB)是一种具有成本效益的可规模化储能系统,其利用资源丰富、低成本的铬和铁作为电解液的活性物质。然而,ICRFB存在Cr^(3.)/Cr^(2+)电化学活性低、负极易产生严重的析氢反应(HER)等问题。本文报道了一种简单的合成策略,即通过自聚合和湿化学还原方法结合煅烧处理,在氮掺杂石墨毡(GF)表面沉积了非晶态铋(Bi)纳米颗粒(NPs),其作为ICRFB的负极材料时可展示出高效的电化学性能。生成的BiNPs与H+形成中间体,极大地抑制了HER副反应。此外,Bi的引入和GF表面的N掺杂通过协同作用显著提高了Fe^(2+)/Fe^(3.)和Cr^(3.)/Cr^(2+)的电化学活性,降低了电荷传递电阻,提高了反应传质速率。在不同的电流密度下,经25次循环,库仑效率仍高达97.7%。在60.0 mA cm^(-2)电流密度下,能量效率达到85.8%,超过了许多其他报道的材料。循环100次后容量达到862.7 mAh/L,约为GF的5.3.。

关键词：铁铬液流电池 Bi 负极氮掺杂石墨毡