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Atomically dispersed Zn-Co-N-C catalyst boosting efficient and robust oxygen reduction catalysis in acid via stabilizing Co-N bonds

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Fundamental Research 2023年第6期3卷 909-917页

作者： Feng Ma Xuan Liu Xiaoming Wang Jiashun Liang Jianyu Huang cameron Priest Jinjia Liu Shuhong Jiao Tanyuan Wang Gang Wu Yunhui Huang Qing Li State Key Laboratory of Material Processing and die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhanHubei 430074China State Key Laboratory of Refractories and Metallurgy Institute of Advanced Materials and NanotechnologyKey Laboratory of Hubei Province for Coal Conversion and New Carbon MaterialsSchool of Chemistry and Chemical EngineeringWuhan University of Science and TechnologyWuhan 430081China Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China department of Chemical and Biological Engineering University at BuffaloThe State University of New YorkBuffaloNY 14260United States State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China National Energy Center for Coal to Clean Fuels Synfuels China Co.LtdHuairou DistrictBeijing 101400China department of Materials Science and Engineering Key Laboratory of Materials for Energy Conversion Chinese Academy of Science(CAS)University of Science and Technology of ChinaHefei 230026China department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantou 515063China

Transition metal supported N-doped carbon(M-N-C)catalysts for oxygen reduction reaction(ORR)are viewed as the promising candidate to replace Pt-group metal(PGM)for proton exchange membrane fuel cells(PEMFCs).However,the stability of M-N-C is extremely challenging due to the demetalation,H_(2)O_(2)attack,*** the strongly oxidative conditions of *** this study,we demonstrate the universal effect of Zn on promoting the stability of atomically dispersed M-Nx/C(M=Co,Fe,Mn)catalysts and the enhancement mechanism is unveiled for the first *** best-performing dual-metal-site Zn-Co-N-C catalyst exhibits a high half-wave potential(E1/2)value of 0.81 V *** hydrogen electrode(RHE)in acid and outstanding durability with no activity decay after 15,000 accelerated degradation test(AdT)cycles at 60℃,surpassing most reported Co-based PGM-free catalysts in acid *** comparison,the Co-N-C in the absence of Zn suffers from a rapid degradation after AdT due to the demetalation and higher H_(2)O_(2)yield.X-ray adsorption spectroscopy(XAS)and density functional theory(dFT)calculations suggest the more negative formation energy(by 1.2 eV)and increased charge transfer of Zn-Co dual-site structure compared to Co-N-C could strength the Co-N bonds against the demetalation and the optimized d-band center accounts for the improved ORR kinetics.

关键词： Electrocatalysis Oxygen reduction reaction Non-noble metal catalysts Metal-nitrogen carbon catalysts demetalation Structural stability

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Canonical Transformations, Quantization, Mutually Unbiased and Other Complete Bases

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Applied Mathematics 2017年第7期8卷 901-919页

作者： donald J. Kouri cameron L. Williams Nikhil Pandya department of Physics University of Houston Houston TX USA department of Mathematics University of Houston Houston TX USA

Using ideas based on supersymmetric quantum mechanics, we design canonical transformations of the usual position and momentum to create generalized “Cartesian-like” positions, W, and momenta, Pw , with unit Poisson brackets. These are quantized by the usual replacement of the classical , x Px by quantum operators, leading to an infinite family of potential “operator observables”. However, all but one of the resulting operators are not Hermitian (formally self-adjoint) in the original position representation. Using either the chain rule or dirac quantization, we show that the resulting operators are “quasi-Hermitian” relative to the x-representation and that all are Hermitian in the W-representation. depending on how one treats the Jacobian of the canonical transformation in the expression for the classical momentum, Pw , quantization yields a) continuous mutually unbiased bases (MUB), b) orthogonal bases (with dirac delta normalization), c) biorthogonal bases (with dirac delta normalization), d) new W-harmonic oscillators yielding standard orthonormal bases (as functions of W) and associated coherent states and Wigner distributions. The MUB lead to W-generalized Fourier transform kernels whose eigenvectors are the W-harmonic oscillator eigenstates, with the spectrum (±1,±i) , as well as “W-linear chirps”. As expected, W,?Pw satisfy the uncertainty product relation: ΔWΔPw ≥1/2 , h=1.

关键词： Canonical Transformations Quantization Mutually Unbiased Bases Complete Bases

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Metamorphic inorganic frameworks that can be switched between single-crystalline states

Metamorphic inorganic frameworks that can be switched betwee...

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中国化学会第十五届固态化学与无机合成学术会议

作者： Cai-Hong Zhan J.M.cameron d.Gabb J.Breternitz d.H.Gregory d.L.Long L.Cronin WestCHEM School of ChemistryUniversity of Glasgow

Here we present a new approach to molecular-crystals using inorganic polyoxometalate anionic ring-shaped molecules to assemble a unique inorganic transition metal oxide crystal, which can be switched between eight different crystalline states by the addition and removal of small molecules from the parent crystal without decomposition of the crystal lattice. The unique nature of this material is underscored by the discovery that the parent crystal(compound 1) undergoes the largest crystal-to-crystal volume transformation in an all-inorganic material thus far reported, simply through dehydration(to give compound 1). This work serves as a starting point for future investigations of all-inorganic single-parent flexi-crystalline materials, allowing the bottom-up design of highly stable inorganic materials with dynamically tuneable properties. This material breaks the precedent that all-inorganic materials, conventionally considered to be ‘hard’, and cannot exhibit ‘soft’ or ‘smart’ behavior and establishes a new genre of functional materials.[1]

关键词： Polyoxometalates Inorganic frameworks Crystalline states

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系外行星系统HAT-P-8凌食事件的测光观测研究

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天文学报 2013年第6期54卷 527-536页

作者：谭泓博王晓彬顾盛宏 Andrew Collier cameron 中国科学院云南天文台昆明650011 中国科学院大学北京100049 School of Physics and Astronomy University of St Andrews

利用云南天文台1 m望远镜以及丽江天文观测站2.4 m望远镜,分别在2009年和2012年对凌食太阳系外行星系统HAT-P-8进行了测光观测.为了提高凌食信号的信噪比,使用coarse de-correlation和SyeRem两种方法对测光数据中的系统误差进行了改正.... 详细信息

利用云南天文台1 m望远镜以及丽江天文观测站2.4 m望远镜,分别在2009年和2012年对凌食太阳系外行星系统HAT-P-8进行了测光观测.为了提高凌食信号的信噪比,使用coarse de-correlation和SyeRem两种方法对测光数据中的系统误差进行了改正.应用MCMC(Markov Chain Monte Carlo)方法对3组数据进行同时分析求解获得了HAT-P-8系统新的物理参数.得到HAT-P-8b的半径为Rp=1.28 R_J(R_J为木星半径),这比该行星发现时Latham等人给出的数值要小,而与最近Mancini等人所得的结果一致.通过线性拟合23个慎重挑选的凌食中心时刻,得到HAT-P-8b新的轨道周期P=3.0763461±0.0000021 d,并且从(O-G)(观测值减计算值)分析中没有发现显著的TTV(Transit Timing Variation)信号.

关键词：行星与卫星个别方法观测方法数据分析

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抗腐蚀耐磨损新合金

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兰州理工大学学报 1982年第S1期 39-44页

作者： C.B.cameron,d.P.Ferriss,董元源美美

经过长期探索,冶金学家已经提供了一种不仅耐腐蚀耐磨损,而且易于成型的合金。有些材料抗磨损,有些材料抗腐蚀,但很少材料既抗磨损又耐腐蚀。一般说,抗磨损材料在严峻的工作环境下很快就被腐蚀,尤其是在高温。而最耐腐蚀的材料却在载... 详细信息

经过长期探索,冶金学家已经提供了一种不仅耐腐蚀耐磨损,而且易于成型的合金。有些材料抗磨损,有些材料抗腐蚀,但很少材料既抗磨损又耐腐蚀。一般说,抗磨损材料在严峻的工作环境下很快就被腐蚀,尤其是在高温。而最耐腐蚀的材料却在载荷作用下擦伤并磨损。偶然能找到兼有上述两种性质的一种材料,但又碰上难于成型的问题。

关键词：合金粉末合金粉抗磨损磨损试验材料试验喷焊层抗腐蚀

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TRIBALOY——一种新型耐磨耐蚀合金

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功能材料 1975年第4期 45-51页

作者： C.B.cameron d.P.Ferriss 思聪

1.引言重要的元件和整机设计人员经常面临的问题之一,即选用既耐元件接触引起的机械磨损又耐介质腐蚀的材料,往往只能取折衷方案。从材料选用的观点来看,这两种性能长期以来都是相矛盾的。可是在许多恶劣环境和要求有长寿命,高精度的场... 详细信息

1.引言重要的元件和整机设计人员经常面临的问题之一,即选用既耐元件接触引起的机械磨损又耐介质腐蚀的材料,往往只能取折衷方案。从材料选用的观点来看,这两种性能长期以来都是相矛盾的。可是在许多恶劣环境和要求有长寿命,高精度的场合对二者又都需要。

关键词：等离子喷射涂层试块钢环镍基合金镍合金 TRIBALOY

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公猪性发育及精液生产

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国外畜牧学(猪与禽) 1988年第4期 29-33页

作者： R. d. A. cameron 朱久明澳大利亚昆士兰大学兽医系

引言影响养猪效益的一个最重要的因素是,每头母猪年产多少活的、健康的,并能存活的仔猪。尽管母猪对受胎率和产仔数影响相当大(Kennedy和Moxley,1978),但是公猪效应也不可忽视。根

关键词：公猪月龄初情期精子发生采精精子数量精液品质

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Flux density measurements for 32 pulsars in the 20 cm observing band

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Research in Astronomy and Astrophysics 2019年第7期19卷 143-150页

作者： Yan-Wei Xie Jing-Bo Wang George Hobbs Jane Kaczmarek di Li Jie Zhang Shi dai Andrew cameron Lei Zhang Chen-Chen Miao Mao Yuan Shen Wang Song-Bo Zhang Heng Xui Ren-Xin Xu School of Physics and Space Science China West Normal UniversityNanchong 637002China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Key Laboratory of Radio Astronomy Chinese Academy of SciencesUrumqi 830011China CSIRO Astronomy and Space Science PO Box 76EppingNSW 1710Australia CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China College of Physics and Electronic Engineering Qilu Normal UniversityJinan 250014China Astronomy department Cornell UniversityIthacaNY 14853USA Purple Mountain Observatory Chinese Academy of SciencesNanjing 21000& China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China department of Astronomy School of PhysicsPeking UniversityBeijing 100871China

Flux densities are fundamental observational parameters that describe a *** the current pulsar catalogue,27% of the listed radio pulsars have no flux density measurement in the 20 cm observing ***,we present the first such measurements for 32 pulsars observed employing the Parkes radio *** have used both archival and new observations to make these *** schemes exist for measuring flux densities and we show how the measured flux densities vary between these methods and how the presence of radio-frequency interference will bias the flux density measurements.

关键词： methods data analysis-pulsars general

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Impact of Marijuana on Response Inhibition: an fMRI Study in Young Adults

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Journal of Behavioral and Brain Science 2011年第3期1卷 124-133页

作者： Andra M. Smith Rocío A. López Zunini Christopher d. Anderson Carmelinda A. Longo Ian cameron Matthew J. Hogan Peter A. Fried 不详

Rationale: Marijuana use in adolescence is prevalent and increasing. Understanding the neural correlates of the impact of this use is critical for policy making and for youth awareness. Objectives The effects of marijuana use on response inhibition were investigated in 19–21-year-olds using functional magnetic resonance imaging (fMRI). Methods: Participants were members of the Ottawa Prenatal Prospective Study, a longitudinal study that collected a unique body of information on participants from infancy to young adulthood including: prenatal drug history, detailed cognitive/behavioral performance, and current and past drug use. This information allowed for the control of an unparalleled number of potentially confounding variables including: prenatal marijuana, nicotine, alcohol, and caffeine exposure and offspring alcohol, marijuana, and nicotine use. Ten marijuana users and 14 nonusers that served as controls performed a Go/No-Go task while fMRI blood oxygen level-dependent response was examined. Results: despite similar task performance, there was a positive relationship between amount of marijuana smoked and activation in right thalamus, premotor cortex and middle frontal gyrus. These regions form part of the neural network responsible for inhibition control. There was also a positive dose dependent relationship with marijuana and activation in inferior parietal lobe and precuneus, also parts of response inhibition pathways. Conclusions: These results suggest a dose dependent alteration in neural functioning during response inhibition after controlling for other prenatal and current drug use. These alterations may be necessary in order to compensate for neural changes in response inhibition circuits caused by long term marijuana use that began during adolescence/young adulthood.

关键词： Prefrontal Cortex fMRI Marijuana Young Adulthood Response Inhibition

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Time windows for postnatal changes in morphology and membrane excitability of genioglossal and oculomotor motoneurons

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World Journal of Neurology 2015年第4期5卷 113-131页

作者： Livia Carrascal JoséLuis Nieto-González Ricardo Pardillo-díaz Rosario Pásaro Germán Barrionuevo Blas Torres William E cameron Pedro Nú?ez-Abades department of Physiology University of Seville department of Neurocience University of Pittsburgh department of Behavioral Neuroscience Oregon Health and Science University departamento de Fisiología Facultad de Farmacia Universidad de Sevilla

Time windows for postnatal changes in morphology and membrane excitability of genioglossal(GG) and oculomotor(OCM) motoneurons(MNs) are yet to be fully described. Analysis of data on brain slices in vitro of the 2 populations of MNs point to a well-defined developmental program that progresses with common age-related changes characterized by:(1) increase of dendritic surface along with length and reshaping of dendritic tree complexity;(2) disappearance of gap junctions early in development;(3) decrease of membrane passive properties, such as input resistance and time constant, together with an increase in the number of cells displaying sag, and modifications in rheobase;(4) action potential shortening and afterhyperpolarization; and(5) an increase in gain and maximum firing frequency. These modifications take place at different time windows for each motoneuronal population. In GG MNs, active membrane properties change mainly during the first postnatal week, passive membrane properties in the second week, and dendritic increasing length and size in the third week of development. In OCM MNs, changes in passive membrane properties and growth of dendritic size take place during the first postnatal week, while active membrane properties and rheobase change during the second and third weeks of development. The sequential order of changes is inverted between active and passive membrane properties, and growth in size does not temporally coincide for both motoneuron populations. These findings are discussed on the basis of environmental cues related to maturation of the respiratory and OCM systems.

关键词： development Motoneurons Respiratory system Oculomotor system Neuronal plasticity

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