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Tuning electronic properties of cobalt phthalocyanines for oxygen reduction and evolution reactions

Science China Chemistry 2024年第1期67卷 398-407页

作者： Jianlin Jiang Zhen Liu Shuaijun Pan Xinnian Xia bing Qin Yang Hu Xuxu Wang Jiamin Lan Yu gu Encai Ou Weijian Xu Joseph J.Richardson Rui guo SINOPEC Research Institute of Petroleum Processing Co. Ltd.Beijing 100083China College of Chemistry and Chemical Engineering Hunan UniversityChangsha 410082China College of Chemistry and Materials Science Hunan Agricultural UniversityChangsha 410128China Department of Chemical Engineering The University of MelbourneParkville 3010Australia College of Environmental Science and Engineering Hunan UniversityChangsha 410082China School of Engineering RMIT UniversityMelbourneVictoria 3001Australia

Metal–phthalocyanines are a class of catalytically active materials promising in energy conversion and storage fields(e.g.,electrocatalysis).However,understanding and controlling the electrochemical properties in metal-phthalocyanine systems is ***,we elucidate the electrocatalytic origins of a series of cobalt-phthalocyanine molecular catalysts and finetune their electronic properties at the atomic level,both experimentally and *** interactions between the cobalt center and the local coordination environment are regulated by introducing either electron-donating or electron-withdrawing groups on the phthalocyanine ligand,and the spin-orbit splitting of cobalt is increased by~0.15 eV compared with the nonsubstituted ***,the aminated cobalt phthalocyanine-based electrocatalysts exhibit low free energies in the ratedetermining steps of the oxygen reduction(-1.68 eV)and oxygen evolution reactions(0.37 eV).This contributes to the high electrocatalytic activity(e.g.,a halfwave potential of 0.84 V and an overpotential of 0.30 V at 10 mAcm^(-2)),featuring a high selectivity of a four-electron pathway(i.e.,a negligible by-product of hydrogen peroxide).These catalysts also exhibit exceptional kinetic current density(Tafel slope of 100 mV dec^(-1))in oxygen reduction reactions,in addition to a superior power density(158 mWcm^(-2))and a high cycling stability(>1,300 cycles)in Zn-air batteries,outperforming the commercial Pt/C and/or RuO2counterparts.

关键词： interfacial wettability molecular catalysts carbon nanotubes density functional theory electrochemistry

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Graphene-anchored sodium single atoms:A highly active and stable catalyst for transesterification reaction

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Nano Research 2024年第6期17卷 4979-4985页

作者： Song-Song Peng Yao Nian Xing-Ru Song Xiang-Bin Shao Chen gu Zhi-Wei Xing Shi-Chao Qi Peng Tan You Han Xiao-Qin Liu Lin-bing Sun State Key Laboratory of Materials-Oriented Chemical Engineering Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)College of Chemical EngineeringNanjing Tech University30 South Puzhu RoadNanjing 211816China School of Chemical Engineering and Technology Tianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Solid strong base catalysts have received considerable attention in various organic reactions due to their facile separation,neglectable corrosion,and environmental *** great progress has been made in the preparation of solid strong base catalysts,it is still challenging to avoid basic sites aggregation on support and active sites loss in reaction ***,we report a tandem redox strategy to prepare Na single atoms on graphene,producing a new kind of solid strong base catalyst(Na1/G).The base precursor NaNO_(3)was first reduced to Na2O by graphene(400℃)and successively to single atoms Na anchored on the graphene vacancies(800℃).Owing to the atomically dispersed of basicity,the resultant catalyst presents high activity toward the transesterification of methanol and ethylene carbonate to synthesize dimethyl carbonate(turnover frequency(TOF)value:125.7 h^(−1)),which is much better than the conventional counterpart Na2O/G and various reported solid strong bases(TOF:1.0-90.1 h^(−1)).Furthermore,thanks to the basicity anchored on graphene,the Na1/G catalyst shows excellent durability during *** work may provide a new direction for the development of solid strong base catalysts.

关键词： solid strong base catalyst basic sites redox graphene single Na atoms

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Volume of fluid simulation of single argon bubble dynamics in liquid steel under RH vacuum conditions

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Journal of Iron and Steel Research International 2024年第4期31卷 828-837页

作者： gu-jun Chen Sheng-ping He College of Materials Science and Engineering Yangtze Normal UniversityChongqing 400044China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

Single argon bubble dynamics in liquid steel under Ruhrstahl-Heraeus(RH)vacuum conditions were simulated using the volume of fluid method,and the ideal gas law was used to consider bubble growth due to heat transfer and pressure *** simulation with a constant bubble density was also performed to validate the numerical method,and the predicted terminal bubble shape and velocity were found to agree with those presented in the Grace diagram and calculated by drag correlation,*** simulation results under RH conditions indicate that the terminal bubble shape and velocity cannot be *** primary bubble growth occurs within a rising distance of 0.3 m owing to heating by the high-temperature liquid steel;subsequently,the bubble continues to grow under equilibrium with the hydrostatic *** the initial diameter is 8-32 mm,the bubble diameter and rising velocity near the liquid surface are 80-200 mm and 0.5-0.8 m/s,*** bubble rises rectilinearly with an axisymmetric shape,and the shape evolution history includes an initial sphere,(dimpled)ellipsoid,and spherical cap with satellite bubbles.

关键词： Bubble dynamics Liquid steel Volume of fluid Bubble growth Bubble shape Rising velocity

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Ultra-simplified diffraction-based computational spectrometer

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Light(Science & Applications) 2024年第6期13卷 1022-1031页

作者： Chuangchuang Chen Honggang gu Shiyuan Liu State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhanHubei430074China Optics Valley Laboratory WuhanHubei430074China

Miniaturizing spectrometers for compact and cost-effective mobile platforms is a major challenge in current spectroscopy research,where conventional spectrometers are impractical due to their bulky *** miniaturized designs primarily rely on precalibrated response functions of nanophotonic structures to encode spectral information captured in a snapshot by detector *** spectrum reconstruction is achieved through computational techniques,but this requires precise component design,high-precision fabrication,and *** propose an ultra-simplified computational spectrometer that employs a one-to-broadband diffraction decomposition strategy facilitated by a numerical regularized transform that depends only on the spectrum of the diffracted *** key feature of our design is the use of a simple,arbitrarily shaped pinhole as the partial disperser,eliminating the need for complex encoding designs and full spectrum *** spectrometer achieves a reconstructed spectral peak location accuracy of better than 1 nm over a 200 nm bandwidth and excellent resolution for peaks separated by 3 nm in a bimodal spectrum,all within a compact footprint of under half an ***,our approach also reveals a breakthrough in broadband coherent diffractive imaging without requiring any prior knowledge of the broadband illumination spectrum,assumptions of non-dispersive specimens,or correction for detector quantum efficiency.

关键词： simplified spectrum illumination

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An internal ballistic model of electromagnetic railgun based on PFN coupled with multi-physical field and experimental validation

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Defence Technology（防务技术） 2024年第2期32卷 254-261页

作者： Benfeng gu Haiyuan Li Baoming Li National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing 210094China

To accelerate the practicality of electromagnetic railguns,it is necessary to use a combination of threedimensional numerical simulation and experiments to study the mechanism of bore *** this paper,a three-dimensional numerical model of the augmented railgun with four parallel unconventional rails is introduced to simulate the internal ballistic process and realize the multi-physics field coupling calculation of the rail gun,and a test experiment of a medium-caliber electromagnetic launcher powered by pulse formation network(PFN)is carried *** test methods such as spectrometer,fiber grating and high-speed camera are used to test several parameters such as muzzle initial velocity,transient magnetic field strength and stress-strain of *** the simulation results and experimental data,the damage condition of the contact surface is analyzed.

关键词： Internal ballistic modeling Electromagnetic rail gun Multi-physics field coupling Experimental validation PFN

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Prediction of liquid circulation flow rate in RH degasser:improvement of decarburization at low atmospheric pressure

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Journal of Iron and Steel Research International 2024年第7期31卷 1661-1667页

The two-fluid model coupled with population balance model was used for simulating the gas-liquid flow in the Ruhrstahl-Heraeus(RH)*** predicted circulation flow rate was compared with that measured from a water model experiment to validate the mathematical ***,influence of snorkel immersion depth on liquid circulation flow rate was numerically investigated under an atmospheric pressure of 101 and 84 kPa,*** result indicates that the circulation flow rate of the RH degasser in the high-altitude area was severely reduced because of the decrease in atmospheric ***,increasing the snorkel immersion depth from 0.5 to 0.7 m can compensate for the decrease in atmospheric *** test result indicates that decarburization rate is significantly enhanced by increasing the snorkel immersion *** optimization,the percentage of heats with a final carbon content less than 0.002 wt.%is significantly increased from 22.0%to 96.4%.

关键词： RH degasser Two-fluid model Population balance model-Circulation flow rate Decarburization Snorkel immersion depth

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A Comparison of Four Neural Networks Algorithms on Locomotion Intention Recognition of Lower Limb Exoskeleton Based on Multi-source Information

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Journal of Bionic Engineering 2024年第1期21卷 224-235页

作者： Duojin Wang Xiaoping gu Hongliu Yu Institute of Rehabilitation Engineering and Technology University of Shanghai for Science and Technology516 Jungong RoadShanghai 200093China Shanghai Engineering Research Center of Assistive Devices 516 Jungong RoadShanghai 200093China

Lower Limb Exoskeletons(LLEs)are receiving increasing attention for supporting activities of daily *** such active systems,an intelligent controller may be *** this paper,we proposed a locomotion intention recognition system based on time series data sets derived from human motion *** of input data and Deep Learning(DL)algorithms,this framework enables the detection and prediction of users’movement *** makes it possible to predict the detection of locomotion modes,allowing the LLEs to provide smooth and seamless *** pre-processed eight subjects were used as input to classify four scenes:Standing/Walking on Level Ground(S/WOLG),Up the Stairs(US),Down the Stairs(DS),and Walking on Grass(WOG).The result showed that the ResNet performed optimally compared to four algorithms(CNN,CNN-LSTM,ResNet,and ResNet-Att)with an approximate evaluation indicator of 100%.It is expected that the proposed locomotion intention system will significantly improve the safety and the effectiveness of LLE due to its high accuracy and predictive performance.

关键词： Lower limb exoskeletons(LLEs) Locomotion intention ResNet Multi-source

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Dynamical Dark Energy in Light of Cosmic Distance Measurements.Ⅱ.A Study Using Current Observations

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Research in Astronomy and Astrophysics 2024年第6期24卷 15-20页

作者： Xiaoma Wang Gan gu Xiaoyong Mu Shuo Yuan Gong-Bo zhao National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China

We extract key information on dark energy from current observations of BAO,OHD and H_(0),and find hints of dynamical behavior of dark *** particular,a dynamical dark energy model whose equation of state crosses-1 is f... 详细信息

关键词： Cosmology (cosmology:)dark energy cosmology:observations

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Evaluating the historical,clinical,and cultural value of the Tian Hui Yi Jian

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Journal of Traditional Chinese Medicine 2024年第1期44卷 220-221页

作者： YU Linyong gu Man China Academy of Chinese Medical Sciences Beijing 100700China Institute for History of Medicine and Medical Literature China Academy of Chinese Medical SciencesBeijing 100700China

Tian Hui Yi Jian was compiled by the Tianhui Medical Manuscripts Compilation Group,which includes scholars from the Institute for History of Medicine and Medical Literature of the China Academy of Chinese Medical Sciences(CACMS),Chengdu University of Traditional Chinese Medicine,Chengdu Institute of Cultural Relics and Archaeology,and Jingzhou Cultural Relics Protection *** was published by the Cultural Relics Press in November *** volume includes images of eight medical manuscripts,along with the Team's annotations,and photographs of a lacquered figurine with meridian-channels and words on its surface.

关键词： surface Chengdu Tian

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Surface diffraction beamline at the SSRF

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Nuclear Science and Techniques 2024年第7期35卷 47-57页

作者： Yue-Liang gu Xu Zheng Xing-Min Zhang Bin zhao guang-Zhi Yin Da-Ming Zhu Yuan-He Sun Xing-Yu Gao Xiao-Long Li Shanghai Advanced Research Institute Chinese Academy of Sciences239 Zhangheng RoadPudong DistrictShanghai201204China

BL02U2 of the Shanghai Synchrotron Radiation Facility is a surface diffraction beamline with a photon flux of 5.5×10^(12) photons/s at 10 keV and a beam size of 160µm×80µm at the sample *** is dedicated to studying surfaces(solid-vacuum,solid-gas)and interfaces(solid-solid,solid-liquid,and liquid-liquid)in nanoscience,condensed matter,and soft matter systems using various surface scattering techniques over an energy range of 4.8-28 keV with transmission and reflection ***,BL02U2 has a high energy resolution,high angular resolution,and low beam divergence,which can provide excellent properties for X-ray diffraction experiments,such as grazing incident X-ray diffraction,X-ray reflectivity,crystal truncation rods,and liquid X-ray *** of in situ environments can also be provided for the samples *** paper describes the setup of the new beamline and its applications in various fields.

关键词： Surface and interface Beamline Surface diffraction Microstructure

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