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Decade Milestone Advancement of Defect-Engineered g-C_(3)N_(4) for Solar Catalytic Applications
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作者 Shaoqi Hou Xiaochun Gao +8 位作者 Xingyue Lv Yilin Zhao Xitao Yin Ying Liu Juan Fang Xingxing Yu Xiaoguang Ma Tianyi Ma Dawei Su 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第4期153-218,共66页
Over the past decade, graphitic carbon nitride(g-C_(3)N_(4)) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C_(3)N_(4) is stil... Over the past decade, graphitic carbon nitride(g-C_(3)N_(4)) has emerged as a universal photocatalyst toward various sustainable carbo-neutral technologies. Despite solar applications discrepancy, g-C_(3)N_(4) is still confronted with a general fatal issue of insufficient supply of thermodynamically active photocarriers due to its inferior solar harvesting ability and sluggish charge transfer dynamics. Fortunately, this could be significantly alleviated by the “all-in-one” defect engineering strategy, which enables a simultaneous amelioration of both textural uniqueness and intrinsic electronic band structures. To this end, we have summarized an unprecedently comprehensive discussion on defect controls including the vacancy/non-metallic dopant creation with optimized electronic band structure and electronic density, metallic doping with ultraactive coordinated environment(M–N_(x), M–C_(2)N_(2), M–O bonding), functional group grafting with optimized band structure, and promoted crystallinity with extended conjugation π system with weakened interlayered van der Waals interaction. Among them, the defect states induced by various defect types such as N vacancy, P/S/halogen dopants, and cyano group in boosting solar harvesting and accelerating photocarrier transfer have also been emphasized. More importantly, the shallow defect traps identified by femtosecond transient absorption spectra(fs-TAS) have also been highlighted. It is believed that this review would pave the way for future readers with a unique insight into a more precise defective g-C_(3)N_(4) “customization”, motivating more profound thinking and flourishing research outputs on g-C_(3)N_(4)-based photocatalysis. 展开更多
关键词 Defect engineering g-C_(3)N_(4) Electronic band structures Photocarrier transfer kinetics Defect states
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Investigating the elliptic anisotropy of identified particles in p-Pb collisions with a multi-phase transport model
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作者 Si-Yu Tang Liang Zheng +1 位作者 Xiao-Ming Zhang Ren-Zhuo Wan 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第2期160-169,共10页
The elliptic azimuthal anisotropy coefficient(v_(2))of the identified particles at midrapidity(|η|<0.8)was investigated in p-Pb collisions at√^(s)NN=5.02 TeV using a multi-phase transport model(AMPT).The calculat... The elliptic azimuthal anisotropy coefficient(v_(2))of the identified particles at midrapidity(|η|<0.8)was investigated in p-Pb collisions at√^(s)NN=5.02 TeV using a multi-phase transport model(AMPT).The calculations of differential v_(2)based on the advanced flow extraction method of light flavor hadrons(pions,kaons,protons,andΛ)in small collision systems were extended to a wider transverse momentum(p_(T))range of up to 8 GeV/c for the first time.The string-melting version of the AMPT model provides a good description of the measured p_(T)-differential v_(2)of the mesons but exhibits a slight deviation from the baryon v_(2).In addition,we observed the features of mass ordering at low p_(T)and the approximate number-of-constituentquark(NCQ)scaling at intermediate p_(T).Moreover,we demonstrate that hadronic rescattering does not have a significant impact on v_(2)in p-Pb collisions for different centrality selections,whereas partonic scattering dominates in generating the elliptic anisotropy of the final particles.This study provides further insight into the origin of collective-like behavior in small collision systems and has referential value for future measurements of azimuthal anisotropy. 展开更多
关键词 Azimuthal anisotropy Small collision systems Transport model
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Intensity Distribution and Phase Vortices of Speckle Fields Generated by Multi-Aperture Random Scattering Screens 被引量:1
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作者 刘曼 宋洪胜 +3 位作者 陈小艺 刘桂媛 滕树云 程传福 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第3期155-158,共4页
随机的散布屏蔽的多孔产生的点缀地的紧张分发和阶段旋涡被模仿,并且旋涡展出像层的结构,脱臼现象在阶段模式由二针孔的孔生产了的本地人,分布其阶段作为有斑纹的结构出现发生,这被发现。为三针孔或四针孔的孔,有许多圆形的明亮的... 随机的散布屏蔽的多孔产生的点缀地的紧张分发和阶段旋涡被模仿,并且旋涡展出像层的结构,脱臼现象在阶段模式由二针孔的孔生产了的本地人,分布其阶段作为有斑纹的结构出现发生,这被发现。为三针孔或四针孔的孔,有许多圆形的明亮的点,出现在点缀谷物,并且在附近的圆形的明亮的点之间有一个旋涡。积极、否定的阶段旋涡格子出现在阶段分布,和这些区域由 isothetic 阶段线表格盘旋不规则的 quadrilaterals 或等边六角形。而且,旋涡的相对位置或明亮的点能被针孔孔改变那些调整。 展开更多
关键词 随机散射屏 强度分布 多孔径 散斑场 旋涡 条纹结构 相位分布 涡旋格子
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Correlation and fractal properties of speckles in the extremely deep Fresnel diffraction region
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作者 宋洪胜 刘曼 +3 位作者 刘桂媛 徐芝伟 滕树云 程传福 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第12期248-254,共7页
Based on the Kirchhoff approximation and the theoretical analysis of the random light fields,the speckle intensity distributions in the extremely deep Fresnel diffraction region are simulated.The fractal property of t... Based on the Kirchhoff approximation and the theoretical analysis of the random light fields,the speckle intensity distributions in the extremely deep Fresnel diffraction region are simulated.The fractal property of the speckles as well as the relation between the speckle intensity distribution and the corresponding random surface is investigated.We design a microscope system to detect experimentally the speckles in the extremely deep Fresnel diffraction region,and the experimental results prove the conclusions drawn from our simulations. 展开更多
关键词 菲涅耳衍射区 分形性质 散斑 基尔霍夫近似 强度分布 检测实验 菲涅尔衍射 随机理论
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Nonautonomous Breather and Rogue Wave in Spinor Bose–Einstein Condensates with Space-Time Modulated Potentials 被引量:1
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作者 丁崔崔 周勤 +3 位作者 徐四六 Houria Triki Mohammad Mirzazadeh 刘文军 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第4期6-10,共5页
To study controlled evolution of nonautonomous matter-wave breathers and rogue waves in spinor Bose–Einstein condensates with spatiotemporal modulation,we focus on a system of three coupled Gross–Pitaevskii equation... To study controlled evolution of nonautonomous matter-wave breathers and rogue waves in spinor Bose–Einstein condensates with spatiotemporal modulation,we focus on a system of three coupled Gross–Pitaevskii equations with spacetime-dependent external potentials and temporally modulated gain-loss distributions.With different external potentials and gain-loss distributions,various solutions for controlled nonautonomous matterwave breathers and rogue waves are derived by the Darboux transformation method,such as breathers and rogue waves on arched and constant backgrounds which have the periodic and parabolic trajectories.Effects of the gain-loss distribution and linear potential on the breathers and rogue waves are studied.Nonautonomous two-breathers on the arched and constant backgrounds are also derived. 展开更多
关键词 EINSTEIN NONAUTONOMOUS PARABOLIC
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Introduction to the Special Issue on New Trends in Statistical Computing and Data Science
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作者 Christophe Chesneau Hassan Doosti 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第8期981-983,共3页
The interface between computer science and statistics has developed considerably in recent years,with exponential progress in the fields of data analysis,stochastic modeling,machine learning,econometrics,simulation,al... The interface between computer science and statistics has developed considerably in recent years,with exponential progress in the fields of data analysis,stochastic modeling,machine learning,econometrics,simulation,algorithms,classification,and networks.Innovative discoveries in this field appear every day,opening new scientific horizons for the modern world.This is especially true in the post-2020 period,with the treatment of large volumes of data that feed the daily operations of large corporations,as well as the development of artificial intelligence,including advanced machine learning techniques,particularly“deep learning”. 展开更多
关键词 HAS operations CORPORATION
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Enhanced resonance frequency in Co2FeAl thin film with different thicknesses grown on flexible graphene substrate
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作者 周偲 袁少康 +8 位作者 朱登玉 白宇明 王韬 刘福福 潘禄禄 冯存芳 张博涵 何大平 汪胜祥 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第3期618-622,共5页
The flexible materials exhibit more favorable properties than most rigid substrates in flexibility,weight saving,mechanical reliability,and excellent environmental toughness.Particularly,flexible graphene film with un... The flexible materials exhibit more favorable properties than most rigid substrates in flexibility,weight saving,mechanical reliability,and excellent environmental toughness.Particularly,flexible graphene film with unique mechanical properties was extensively explored in high frequency devices.Herein,we report the characteristics of structure and magnetic properties at high frequency of Co2FeAl thin film with different thicknesses grown on flexible graphene substrate at room temperature.The exciting finding for the columnar structure of Co2FeAl thin film lays the foundation for excellent high frequency property of Co2FeAl/flexible graphene structure.In-plane magnetic anisotropy field varying with increasing thickness of Co2FeAl thin film can be obtained by measurement of ferromagnetic resonance,which can be ascribed to the enhancement of crystallinity and the increase of grain size.Meanwhile,the resonance frequency which can be achieved by the measurement of vector network analyzer with the microstrip method increases with increasing thickness of Co2FeAl thin film.Moreover,in our case with graphene film,the resonance magnetic field is quite stable though folded for twenty cycles,which demonstrates that good flexibility of graphene film and the stability of high frequency magnetic property of Co2FeAl thin film grown on flexible graphene substrate.These results are promising for the design of microwave devices and wireless communication equipment. 展开更多
关键词 enhanced resonance frequency magnetic resonance field flexible graphene substrate
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Studying the efficacy of isolation as a control strategy and elimination of tuberculosis in India:A mathematical model
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作者 Archana Singh Bhadauria Hom Nath Dhungana +2 位作者 Vinay Verma Stephen Woodcock Tapan Rai 《Infectious Disease Modelling》 CSCD 2023年第2期458-470,共13页
India has the highest burden of both tuberculosis(TB)and multidrug-resistant TB(MDRTB)based on the WHO Global TB Report 2019.Although the available data suggest that the total TB incidence has declined,the absolute nu... India has the highest burden of both tuberculosis(TB)and multidrug-resistant TB(MDRTB)based on the WHO Global TB Report 2019.Although the available data suggest that the total TB incidence has declined,the absolute number of new cases is still increasing.The number of reported TB cases in India in 2018 was 2.2 million,which was 1.5 million in 2009.About 47%increment in TB case notification in India within a decade shows a persistent public health problem.India contributes about 22%of the World's TB burden.Indian National Strategic Plan 2017e2025,sets out the government plans to eliminate TB by 2025.However,the milestone seems unrealistic to achieve the TB eradication goal by 2025.We developed a five-dimensional mathematical model to understand the TB dynamics in India and investigate the possibility of the earliest TB eradication time frame.The model stratifies the entire TB class into three different classes as drug-sensitive(DS),MDR,and isolated classes.The effective reproduction number,equilibrium points,and stability analysis of the model were carried out.This model predicts the total estimated cases of DS-TB and MDR-TB from 2018 to 2035 through numerical simulation and suggests that TB may be eliminated by 2035 in India if the treatment success rate could be achieved to 95%,by contact tracing and isolating at least 50%of MDR-TB. 展开更多
关键词 Multi-drug resistant Drug-sensitive ISOLATION Reproduction number Mathematical modelling
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Improved carrier injection and confinement in InGaN light-emitting diodes containing GaN/AlGaN/GaN triangular barriers 被引量:2
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作者 程立文 马剑 +9 位作者 曹常锐 徐作政 兰天 杨金彭 陈海涛 于洪岩 吴曙东 尧舜 曾祥华 徐仔全 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第8期48-52,共5页
In this study, an InGaN lighting-emitting diode(LED) containing GaN/AlGaN/GaN triangular barriers is proposed and investigated numerically. The simulation results of output performance, carrier concentration, and radi... In this study, an InGaN lighting-emitting diode(LED) containing GaN/AlGaN/GaN triangular barriers is proposed and investigated numerically. The simulation results of output performance, carrier concentration, and radiative recombination rate indicate that the proposed LED has a higher output power and an internal quantum efficiency, and a lower efficiency droop than the LED containing conventional GaN or AlGaN barriers. These improvements mainly arise from the modified energy bands, which is evidenced by analyzing the LED energy band diagram and electrostatic field near the active region.The modified energy bands effectively improve carrier injection and confinement, which significantly reduces electron leakage and increases the rate of radiative recombination in the quantum wells. 展开更多
关键词 物理学 中国 理论分析 科学研究
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The Reverse Order Law for Moore-Penrose Inverse of Closed Operators 被引量:3
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作者 DU Fa-peng XUE Yi-feng 《Chinese Quarterly Journal of Mathematics》 CSCD 2013年第1期139-146,共8页
In this paper, the reverse order law for the Moore-Penrose inverse of closed linear operators with closed range is investigated by virtue of the Norm-preserving extension of the bounded linear operators. The results g... In this paper, the reverse order law for the Moore-Penrose inverse of closed linear operators with closed range is investigated by virtue of the Norm-preserving extension of the bounded linear operators. The results generalize some results obtained by S Izumino in [12]. 展开更多
关键词 reverse order law norm-preserving extension Moore-Penrose inverse
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Metal-organic-framework-derived formation of Co–N-doped carbon materials for efficient oxygen reduction reaction 被引量:2
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作者 Hao Tian Chi Zhang +5 位作者 Panpan Su Zhangfeng Shen Hao Liu Guoxiu Wang Shaomin Liu Jian Liu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第1期137-143,I0005,共8页
Non-precious metal nitrogen-doped carbonaceous materials have attracted tremendous attention in the field of electrochemical energy storage and conversion.Herein,we report the designed synthesis of a novel series of C... Non-precious metal nitrogen-doped carbonaceous materials have attracted tremendous attention in the field of electrochemical energy storage and conversion.Herein,we report the designed synthesis of a novel series of Co-N-C nanocomposites and their evaluation of electrochemical properties.Novel yolkshell structured Co nanoparticles@polymer materials are fabricated from the facile coating polymer strategy on the surface of ZIF-67.After calcination in nitrogen atmosphere,the Co–N–C nanocomposites in which cobalt metal nanoparticles are embedded in the highly porous and graphitic carbon matrix are successfully achieved.The cobalt nanoparticles containing cobalt metal crystallites with an oxidized shell and/or smaller(or amorphous)cobalt-oxide deposits appear on the surface of graphitic carbons.The prepared Co–N–C nanoparticles showed favorable electrocatalytic activity for oxygen reduction reactions,which is attributed to its high graphitic degree,large surface area and the large amount existence of Co–N active sites. 展开更多
关键词 Metal-organic-framework Resin polymer Oxygen reduction reaction ELECTROCATALYSTS
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Influence of Parameters of Optical Fibers on Optical Soliton Interactions 被引量:1
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作者 周勤 《Chinese Physics Letters》 SCIE EI CAS CSCD 2022年第1期7-10,共4页
The interaction between optical solitons is of great significance for studying interaction between light and matter and development of all-optical devices, and is conducive to the design of integrated optical path. Op... The interaction between optical solitons is of great significance for studying interaction between light and matter and development of all-optical devices, and is conducive to the design of integrated optical path. Optical soliton interactions for the nonlinear Schr¨odinger equation are investigated to improve the communication quality and system integration. Solutions of the equation are derived and used to analyze the interaction of two solitons.Some suggestions are put forward to weaken their interactions. 展开更多
关键词 INTERACTION SOLITONS EQUATION
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Oxygen redox chemistry in lithium-rich cathode materials for Li-ion batteries:Understanding from atomic structure to nano-engineering 被引量:1
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作者 Majid Farahmandjou Shuoqing Zhao +3 位作者 Wei-Hong Lai Bing Sun Peter.H.L.Notten Guoxiu Wang 《Nano Materials Science》 EI CAS CSCD 2022年第4期322-338,共17页
Lithium-rich oxide compounds have been recognized as promising cathode materials for high performance Li-ion batteries,owing to their high specific capacity.However,it remains a great challenge to achieve the fully re... Lithium-rich oxide compounds have been recognized as promising cathode materials for high performance Li-ion batteries,owing to their high specific capacity.However,it remains a great challenge to achieve the fully reversible anionic redox reactions to realize high capacity,high stability,and low voltage hysteresis for lithiumrich cathode materials.Therefore,it is critically important to comprehensively understand and control the anionic redox chemistry of lithium-rich cathode materials,including atomic structure design,and nano-scale materials engineering technologies.Herein,we summarize the recent research progress of lithium-rich cathode materials with a focus on redox chemistry.Particularly,we highlight the oxygen-based redox reactions in lithium-rich metal oxides,with critical views of designing next generation oxygen redox lithium cathode materials.Furthermore,we purposed the most promising strategies for improving the performances of lithium-rich cathode materials with a technology-spectrum from the atomic scale to nano-scale. 展开更多
关键词 Oxygen redox chemistry Lithium-rich cathode Li-ion batteries Atomic structure Nano-engineering
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Unified Approach to the Expression for the Moore-Penrose Inverse of a- xy 被引量:1
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作者 D U Fa-peng XUE Yi-feng 《Chinese Quarterly Journal of Mathematics》 CSCD 2014年第3期465-474,共10页
Let A be an unital C*-algebra, a, x and y are elements in A. In this paper, we present a method how to calculate the Moore-Penrose inverse of a- xy*and investigate the expression for some new special cases of(a- xy*).
关键词 C*-algebra generalized inverse Moore-Penrose inverse
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AC Alternating-Current Loss Analyses of a Thin High-Temperature Superconducting Tube Carrying AC Transport Current in AC External Magnetic Field
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作者 皮伟 王银顺 +1 位作者 董瑾 陈雷 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第3期274-277,共4页
AC 损失特征在上的数字模拟一薄高温度超导(HTS ) 试管被介绍。HTS 导体的几何学与可以忽略的厚度作为一个试管被建模,并且当交流外部地适用,假定与一样的阶段带运输电流磁性对轴保持垂直。与豆子批评当前的模型,一起基于交流损失的... AC 损失特征在上的数字模拟一薄高温度超导(HTS ) 试管被介绍。HTS 导体的几何学与可以忽略的厚度作为一个试管被建模,并且当交流外部地适用,假定与一样的阶段带运输电流磁性对轴保持垂直。与豆子批评当前的模型,一起基于交流损失的古典理论批评当前的密度 jc 和交流损失 Q 的分发借助于数字分析被获得。结果在对实验的很好的同意。双山峰侧面沿着方位角角度在批评当前的密度分发的曲线被观察。这个数字模拟方法对一个薄 HTS 试管合适,它可能在由涂的超导体组成的一种薄试管配置上是适用的。 展开更多
关键词 高温超导导线 交流电流 损耗分析 运输 外磁场 临界电流密度 数值模拟方法 流管
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Bayesian methods in reporting and managing Australian clinical indicators
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作者 Peter P Howley Stephen J Hancock +2 位作者 Robert W Gibberd Sheuwen Chuang Frank A Tuyl 《World Journal of Clinical Cases》 SCIE 2015年第7期625-634,共10页
Sustained clinical improvement is unlikely without appropriate measuring and reporting techniques. Clinical indicators are tools to help assess whether a standard of care is being met. They are used to evaluate the po... Sustained clinical improvement is unlikely without appropriate measuring and reporting techniques. Clinical indicators are tools to help assess whether a standard of care is being met. They are used to evaluate the potential to improve the care provided by healthcare organisations(HCOs). The analysis and reporting of these indicators for the Australian Council on Healthcare Standards have used a methodology which estimates, for each of the 338 clinical indicators, the gains in the system that would result from shifting the mean proportion to the 20 th centile. The results are used to provide a relative measure to help prioritise quality improvement activity within clinical areas, rather than simply focus on "poorer performing" HCOs. The method draws attention to clinical areas exhibiting larger between-HCO variation and affecting larger numbers of patients. HCOs report data in six-month periods, resulting in estimated clinical indicator proportions which may be affected by small samples and sampling variation. Failing to address such issues would result in HCOs exhibiting extremely small and large estimated proportions and inflated estimates of the potential gains in the system. This paper describes the 20 th centile method of calculating potential gains for the healthcare system by using Bayesian hierarchical models and shrinkage estimators to correct for the effects of sampling variation, and provides an example case in Emergency Medicine as well as example expert commentary from colleges based upon the reports. The application of these Bayesian methods enables all collated data to be used, irrespective of an HCO's size, and facilitates more realistic estimates of potential system gains. 展开更多
关键词 Clinical INDICATORS Improvement System GAINS BAYESIAN Statistical models
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Morphological Characterization of Graphene Flake Networks Using Minkowski Functionals 被引量:1
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作者 Igor Levchenko Jinghua Fang +2 位作者 Kostya (Ken) Ostrikov Ludovico Lorello Michael Keidar 《Graphene》 2016年第1期25-34,共10页
Two Minkowski functionals were tested in the capacity of morphological descriptors to quantitatively compare the arrays of vertically-aligned graphene flakes grown on smooth and nanoporous alumina and silica surfaces.... Two Minkowski functionals were tested in the capacity of morphological descriptors to quantitatively compare the arrays of vertically-aligned graphene flakes grown on smooth and nanoporous alumina and silica surfaces. Specifically, the Euler-Poincaré characteristic and fractal dimension graphs were used to characterize the degree of connectivity and order in the systems, i.e. in the graphene flake patterns of petal-like and tree-like morphologies on solid substrates, and meshlike patterns (networks) grown on nanoporous alumina treated in low-temperature inductivelycoupled plasma. It was found that the Minkowski functionals return higher connectivity and fractal dimension numbers for the graphene flakepatterns with more complex morphologies, and indeed can be used as morphological descriptors to differentiate among various configurations of vertically-aligned graphene flakes grown on surfaces. 展开更多
关键词 Graphene Flakes Minkowski Functionals Euler-Poincaré Characteristic Connectivity
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Near-infrared imaging survey of faint companions around young dwarfs in the Pleiades cluster
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作者 Yoichi Itoh Yumiko Oasa +4 位作者 Hitoshi Funayama Masahiko Hayashi Misato Fukagawa Toshio Hashiguchi Thayne Currie 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2011年第3期335-344,共10页
We conducted a near-infrared imaging survey of 11 young dwarfs in the Pleiades cluster using the Subaru Telescope and the near-infrared coronagraph imager. We found ten faint point sources,with magnitudes as faint as ... We conducted a near-infrared imaging survey of 11 young dwarfs in the Pleiades cluster using the Subaru Telescope and the near-infrared coronagraph imager. We found ten faint point sources,with magnitudes as faint as 20 mag in the K-band,with around seven dwarfs.Comparison with the Spitzer archive images revealed that a pair of the faint sources around V 1171 Tau is very red in infrared wavelengths,which indicates very low-mass young stellar objects.However,the results of our follow-up proper motion measurements implied that the central star and the faint sources do not share common proper motions,suggesting that they are not physically associated. 展开更多
关键词 近红外成像 星团 矮星 近红外线 图像存档 年轻星体 运动测量 物理相关
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Enhanced confinement synthesis of atomically dispersed Fe-N-C catalyst from resin polymer for oxygen reduction
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作者 Ailing Song Hao Tian +5 位作者 Wang Yang Wu Yang Yuhan Xie Hao Liu Guoxiu Wang Guangjie Shao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第2期630-636,共7页
Due to larger atom utilization,unique electronic properties and unsaturated coordination,atomically dispersed non-precious metal catalysts with outstanding performances have received great attention in electrocatalysi... Due to larger atom utilization,unique electronic properties and unsaturated coordination,atomically dispersed non-precious metal catalysts with outstanding performances have received great attention in electrocatalysis.Considering the challenge of serious aggregation,rational synthesis of an atomic catalyst with good dispersion of atoms is paramount to the development of these catalysts.Herein,we report an enhanced confinement strategy to synthesize a catalyst comprised of atomically dispersed Fe supported on porous nitrogen-doped graphitic carbon from the novel and more cross-linkable Melamine-Glyoxal Resin.Densified isolated grid trapping,excessive melamine restricting,and nitrogen anchoring are strongly combined to ensure the final atomic-level dispersion of metal atoms.Experimental studies revealed enhanced kinetics of the obtained catalyst towards oxygen reduction reaction(ORR).This catalytic activity originates from the highly active surface with atomically dispersed iron sites as well as the multi-level three-dimensional structure with fast mass and electron transfer.The enhanced confinement strategy endows the resin-derived atomic catalyst with a great prospect to develop for commercialization in future. 展开更多
关键词 Non-precious metal catalysts Atomic catalyst Oxygen reduction reaction Confinement synthesis
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Cross-Correlation of Station-to-Station Free Surface Elevation Time Series for Breaking Water Waves
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作者 Raphael Mukaro 《Applied Mathematics》 2018年第2期138-152,共15页
Free surface elevation time series of breaking water waves were measured in a laboratory flume. This was done in order to analyze changes in wave characteristics as the waves propagated from deep water to the shore. A... Free surface elevation time series of breaking water waves were measured in a laboratory flume. This was done in order to analyze changes in wave characteristics as the waves propagated from deep water to the shore. A pair of parallel- wire capacitive wave gages was used to simultaneously measure free surface elevations at different positions along the flume. One gage was kept fixed near the wave generator to provide a reference while the other was moved in steps of 0.1 m in the vicinity of the break point. Data from these two wave gages measured at the same time constitute station-to-station free surface elevation time series. Fast Fourier Transform (FFT) based cross-correlation techniques were employed to determine the time lag between each pair of the time series. The time lag was used to compute the phase shift between the reference wave gage and that at various points along the flume. Phase differences between two points spaced 0.1 m apart were used to calculate local mean wave phase velocity for a point that lies in the middle. Results show that moving from deep water to shallow water, the measured mean phase velocity decreases almost linearly from about 1.75 m/s to about 1.50 m/s at the break point. Just after the break point, wave phase velocity abruptly increases to a maximum value of 1.87 m/s observed at a position 30 cm downstream of the break point. Thereafter, the phase velocity decreases, reaching a minimum of about 1.30 m/s. 展开更多
关键词 Turbulence Plunging BREAKER Time Series CROSS-CORRELATION Relative PHASE PHASE Velocity
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