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Nano Research 2024年第8期17卷 6803-6819页

作者： Xiaofeng Xiao Xiaochun Tian Junpeng li Fan Yang Rui bai Feng Zhao Key Laboratory of Urban Pollutant Conversion Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China

Microorganisms are rich in heteroatoms,which can be self-doped to form active sites during pyrolysis and loaded on microbederived carbonaceous *** recent years,microbe-derived carbonaceous materials,characterized with abundant selfdoping sites,have been continuously developed as cost-effective electrocatalysts for oxygen reduction reaction(ORR).To fully unlock the catalytic potential of microbe-derived carbonaceous materials,a comprehensive analysis of catalytic sites and mechanisms for ORR is *** paper provides a summary of the ORR catalytic performance of microbe-derived carbonaceous materials reported to date,with a specific focus on the self-doping sites introduced during their pyrolytic *** highlights the mono-or co-doping sites involving nonmetallic elements such as oxygen(O),nitrogen(N),phosphorus(P),and sulfur(S)atoms,as well as covers the doping of metallic iron(Fe)atoms with various coordination configurations in microbe-derived carbonaceous *** the impact of these self-doping sites on ORR catalytic performance can guide the design of doping sites in microbe-derived carbonaceous *** approach has the potential to maximize electrocatalytic activity of microbe-derived carbonaceous materials and contributes to the development of more efficient and cost-effective carbonaceous electrocatalysts.

关键词： electrocatalysis heteroatoms self-doped single atom catalyst microbe-derived carbonaceous material

Automatic velocity picking based on optimal key points tracking algorithm

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Petroleum Science 2024年第2期21卷 903-917页

作者： Yong-Hao Wang Wen-Kai Lu Song-bai Jin Yang li Yu-Xuan li Xiao-Feng Gu The Institute for Artificial Intelligence(ThuaI) Tsinghua UniversityBeijing100084China State Key Laboratory of Intelligent Technology and Systems Tsinghua UniversityBeijing100084China Beijing National Research Center for Information Science and Technology(BNRist) Beijing100084China The Department of Automation Tsinghua UniversityBeijing100084China

Picking velocities from semblances manually is laborious and necessitates experience. Although various methods for automatic velocity picking have been developed, there remains a challenge in efficiently incorporating information from nearby gathers to ensure picked velocity aligns with seismic horizons while also improving picking accuracy. The conventional method of velocity picking from a semblance volume is computationally demanding, highlighting a need for a more efficient strategy. In this study, we introduce a novel method for automatic velocity picking based on multi-object tracking. This dynamic tracking process across different semblance panels can integrate information from nearby gathers effectively while maintaining computational efficiency. First, we employ accelerated density clustering on the velocity spectrum to discern cluster centers without the requirement for prior knowledge regarding the number of clusters. These cluster centers embody the maximum likelihood velocities of the main subsurface structures. Second, our proposed method tracks key points within the semblance volume. Kalman filter is adopted to adjust the tracking process, followed by interpolation on these tracked points to construct the final velocity model. Our synthetic data example demonstrates that our proposed algorithm can effectively rectify the picking errors of the clustering algorithm. We further compare the performances of the clustering method(CM), the proposed tracking method(TM), and the variational method(VM) on a field dataset from the Gulf of Mexico. The results attest that our method offers superior accuracy than CM, achieves comparable accuracy with VM, and benefits from a reduced computational cost.

关键词： Velocity picking Multi-object tracking Density clustering Kalman filter

Multi-prior physics-enhanced neural network enables pixel super-resolution and twin-imagefree phase retrieval from single-shot hologram

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Opto-Electronic Advances 2024年第9期7卷 22-38页

作者： Xuan Tian Runze li Tong Peng Yuge Xue Junwei Min Xing li Chen bai Baoli Yao State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China University of Chinese Academy of Sciences Beijing 100049China.

Digital in-line holographic microscopy(DIHM)is a widely used interference technique for real-time reconstruction of living cells’morphological information with large space-bandwidth product and compact ***,the need for a larger pixel size of detector to improve imaging photosensitivity,field-of-view,and signal-to-noise ratio often leads to the loss of sub-pixel information and limited pixel ***,the twin-image appearing in the reconstruction severely degrades the quality of the reconstructed *** deep learning(DL)approach has emerged as a powerful tool for phase retrieval in DIHM,effectively addressing these ***,most DL-based strategies are datadriven or end-to-end net approaches,suffering from excessive data dependency and limited generalization ***,a novel multi-prior physics-enhanced neural network with pixel super-resolution(MPPN-PSR)for phase retrieval of DIHM is *** encapsulates the physical model prior,sparsity prior and deep image prior in an untrained deep neural *** effectiveness and feasibility of MPPN-PSR are demonstrated by comparing it with other traditional and learning-based phase retrieval *** the capabilities of pixel super-resolution,twin-image elimination and high-throughput jointly from a single-shot intensity measurement,the proposed DIHM approach is expected to be widely adopted in biomedical workflow and industrial measurement.

关键词： optical microscopy quantitative phase imaging digital holographic microscopy deep learning super-resolution

Construction of novel P-Si/TiO_(2)/HfO_(2)/MoS_(2)/Pt heterophotocathode for enhanced photoelectrochemical water splitting

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Nano Research 2024年第5期17卷 4428-4436页

作者： Jiaru li Jiayu bai Songjie Hu Wenyu Yuan Yuyu Bu Xiaohui Guo Key Lab of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education Shaanxi Key Laboratory for Carbon Neutral TechnologyThe College of Chemistry and Materials ScienceNorthwest UniversityXi'an 710069China Key Lab of Wide Band-Gap Semiconductor Materials and Devices School of MicroelectronicsXidian UniversityXi’an 710071China Key Lab of Macromolecular Science of Shaanxi Province Key Laboratory of Applied Surface and Colloid ChemistryMinistry of EducationSchool of Chemistry&Chemical EngineeringShaanxi Normal UniversityXi'an 710062China

Photoelectrochemical devices have been developed to enable the conversion of solar ***,their commercial potential is restricted by the limited stability of the materials *** enhance the stability of photocathode and its solar water splitting performance,a P-Si/TiO_(2)/HfO_(2)/MoS_(2)/Pt composite photocathode is developed in this *** novel TiO_(2)/HfO_(2)/MoS_(2) serial nanostructure provides excellent stability of the photocathode,and optimizes the interface energy barrier to further facilitate the transfer process of photogenerated carriers within the *** best P-Si/TiO_(2)/HfO_(2)/MoS_(2)/Pt photocathode demonstrates an initial potential of 0.5 V(***)and a photocurrent density of-29 mA/cm^(2) at 0 V(***).Through intensity modulated photocurrent spectroscopy and photoluminescence test,it is known that the enhanced water splitting performance is attributed to the optimized carrier transfer *** findings provide a feasible strategy for the stability and photon quantum efficiency enhancement of silicon-based photocathode devices.

关键词： photoelectrochemical water splitting stability surface/interface engineering HfO_(2)layer

Carbon-based interface engineering and architecture design for high-performance lithium metal anodes

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Carbon Energy 2024年第1期6卷 207-235页

作者： Na Zhu Yuxiang Yang Yu li Ying bai Junfeng Rong Chuan Wu SINOPEC Research Institute of Petroleum Processing Co. Ltd.BeijingChina Beijing Key Laboratory of Environmental Science and Engineering School of Materials Science and EngineeringBeijing Institute of TechnologyBeijingChina Yangtze Delta Region Academy of Beijing Institute of Technology JiaxingChina

Metallic lithium(li)is considered the“Holy Grail”anode material for the nextgeneration of li batteries with high energy density owing to the extraordinary theoretical specific capacity and the lowest negative electrochemical ***,owing to inhomogeneous li-ion flux,li anodes undergo uncontrollable li deposition,leading to limited power output and practical *** materials and their composites with controllable structures and properties have received extensive attention to guide the homogeneous growth of li to achieve high-performance li *** this review,the correlation between the behavior of li anode and the properties of carbon materials is ***,we review emerging strategies for rationally designing high-performance li anodes with carbon materials,including interface engineering(stabilizing solid electrolyte interphase layer and other functionalized interfacial layer)and architecture design of host carbon(constructing three-dimension structure,preparing hollow structure,introducing lithiophilic sites,optimizing geometric effects,and compositing with li).Based on the insights,some prospects on critical challenges and possible future research directions in this field are *** is anticipated that further innovative works on the fundamental chemistry and theoretical research of li anodes are needed.

关键词： carbon materials dendrites hosts interfacial layers li metal anodes

Thermal stability of permafrost under U-shaped crushed rock embankment of the Qinghai-Tibet Railway

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Advances in Climate Change Research 2024年第1期15卷 158-169页

作者： Kun-Ming XU Guan-li JIANG Ji CHEN Qing-bai WU State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China Beiluhe Observation Station of Frozen Soil Environment and Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000China

The U-shaped crushed rock embankment(UCRE),of which widely utilized in the permafrost regions along the Qinghai-Tibet Railway,has the capability to rapidly reduce the ground temperature of the underlying ***,there remains uncertainty regarding the adaptation of UCRE to climate change and its long-term cooling *** study focuses on nine UCRE monitoring sites along the Qinghai-Tibet Railway to analyze the dynamic variations of the ground temperature underlying permafrost from 2006 to *** efficiency of UCRE in stabilizing permafrost temperature in different permafrost zones is evaluated by considering the permafrost table,ground temperature,and MAGT,as well as the temperature difference between the top and bottom of the crushed rock layer and the ground temperature variation index(GTVI).The results show that UCRE is suitable for application in extremely unstable warm permafrost regions where the MAGT is higher than-0.5℃.Moreover,UCRE effectively diminishes the disparity in permafrost thermal stability between the sunny and shaded shoulders of the *** short-term and long-term effect of cooling permafrost is experiencing a change related with permafrost ***,in stable cold permafrost regions with MAGT lower than-1.5℃,the long-term cooling effect of UCRE on permafrost seems to gradually di-minishes,but UCRE continues to fulfill the role of stabilizing the underlying permafrost thermal state over the *** results show that UCRE can quickly restore and stabilize the thermal state of permafrost in the early stages of construction,and adapt to the influence of future climate *** findings provide important guidance for understanding the variations of permafrost thermal stability beneath the embankment in permafrost regions,as well as for improving the embankment stability and operational safety of the Qinghai-Tibet Railway.

关键词： Qinghai-Tibet Railway U-shaped crushed rock embankment Climate change Permafrost zone Ground temperature variation index Long-term coolingrole

Micro segment analysis of supercritical methane thermal-hydraulic performance and pseudo-boiling in a PCHE straight channel

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Petroleum Science 2024年第2期21卷 1275-1289页

作者： Qian li Zi-Jie lin liu Yang Yue Wang Yue li Wei-hua Cai Laboratory of Thermo-Fluid Science and Nuclear Engineering Northeast Electric Power UniversityJilin132000JilinChina School of Energy and Power Engineering Northeast Electric Power UniversityJilin132000JilinChina

The printed circuit heat exchanger(PCHE) is receiving wide attention as a new kind of compact heat exchanger and is considered as a promising vaporizer in the LNG process. In this paper, a PCHE straight channel in the length of 500 mm is established, with a semicircular cross section in a diameter of 1.2 *** simulation is employed to investigate the flow and heat transfer performance of supercritical methane in the channel. The pseudo-boiling theory is adopted and the liquid-like, two-phase-like, and vapor-like regimes are divided for supercritical methane to analyze the heat transfer and flow *** results are presented in micro segment to show the local convective heat transfer coefficient and pressure drop. It shows that the convective heat transfer coefficient in segments along the channel has a significant peak feature near the pseudo-critical point and a heat transfer deterioration when the average fluid temperature in the segment is higher than the pseudo-critical point. The reason is explained with the generation of vapor-like film near the channel wall that the peak feature related to a nucleateboiling-like state and heat transfer deterioration related to a film-boiling-like state. The effects of parameters, including mass flow rate, pressure, and wall heat flux on flow and heat transfer were *** calculating of the averaged heat transfer coefficient of the whole channel, the traditional method shows significant deviation and the micro segment weighted average method is adopted. The pressure drop can mainly be affected by the mass flux and pressure and little affected by the wall heat flux. The peak of the convective heat transfer coefficient can only form at high mass flux, low wall heat flux, and near critical pressure, in which condition the nucleate-boiling-like state is easier to appear. Moreover,heat transfer deterioration will always appear, since the supercritical flow will finally develop into a filmboiling-like state. So hea

关键词： Printed circuit heat exchanger Vaporization Supercritical methane Pseudo-boiling Micro segment analysis

Exploring the Interplay between Local Chain Structure and Stress Distribution in Polymer Networks

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Chinese Journal of Polymer Science 2024年第6期42卷 874-885页

作者： Jin-Tong Xue Yang bai li Peng Xian-Bo huang Zhao-Yan Sun School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China National-certified Enterprise Technology Center Kingfa Science and Technology Co.Ltd.Guangzhou510663China

The mechanical behavior of polymer networks is intrinsically correlated with the local chain topology and chain *** this study,we delve into this relationship through the lens of coarse-grained molecular dynamics(CG-MD)*** aim is to illuminate the intricate interplay between local topology and stress distribution within polymer monomers,cross-linkers,and various components with distinct cross-link connections,thereby elucidating their collective impact on the mechanical properties of polymer *** mainly focus on how specific local structures contribute to the overall mechanical response of the *** particular,we employ local stress analysis to unravel the mechanics of these *** findings reveal the diverse responses of individual components,such as junctions,strands,cross-linkers between junctions,and dangling chain ends,when subjected to ***,we observe that these components exhibit varying degrees of deformation tolerance,underscoring the significance of their roles in determining the mechanical characteristics of the *** investigations highlight junctions as primary contributors to stress accumulation,and particles with higher local stress showing a stronger correlation between stress and Voronoi ***,our results indicate that both strands and cross-linkers between junctions exhibit heightened stress levels as strand lengths *** study enhances our understanding of the multifaceted factors governing the mechanical attributes of cross-linked polymer systems at the microstructural level.

关键词： Local chain structure Local stress Molecular dynamics simulation

Solidification crack characteristics and sensitivity of peritectic steel

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Journal of Iron and Steel Research International 2024年第7期31卷 1668-1679页

作者： Ya-qiang li Jian-hua liu Zi-ming Wang Ying-ying li Yang He Xiao-wei li Department of Automotive Engineering Hebei Vocational University of Technology and EngineeringXingtai 054000HebeiChina Hebei Special Vehicle Modification Technology Innovation Center Hebei Vocational University of Technology and EngineeringXingtai 054000HebeiChina Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China School of Petroleum and Natural Gas Engineering Changzhou UniversityChangzhou 213164JiangsuChina

The characteristics and sensitivity of solidification cracks in peritectic steels were investigated using directional solidifi-cation *** cracks were observed in both hypoperitectic steels(12CrlMoV,15CrMo)and hyper-peritectic steel(20CrMo)during solidification at growth velocities of 15,50,and 80 pm/*** the dendritic boundaries,sulphide precipitates were found,promoting crack *** on the statistical analysis of interdendritic cracks in peritectic steels,the area ratio(RA)of interdendritic cracks in a directional solidification structure was proposed to evaluate the crack sensitivity of peritectic ***,the crack sensitivities of peritectic steels(12CrlMoV,15CrMo,and 20CrMo)were tested,evaluated,and compared with the surface crack rates of three types of steels produced from a steel *** results demonstrated that RA was in good agreement with that of the steel plant,and the crack sensitivity of 12CrlMoV steel was the strongest,followed by that of 15CrMo and 20CrMo ***,RA can be used to evaluate the crack sensitivity of peritectic steel.

关键词： Peritectic steel-Directional solidification Growth velocity Dendritic structure Solidification crack Crack sensitivity

Role of Vickers ligament in the Pathogenesis of Madelung Deformity

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Current Medical Science 2024年第4期44卷 735-740页

作者： Ge XIONG Wei ZHENG li-hua GONG Department of Hand Surgery Beijing Jishuitan HospitalCapital Medical UniversityBeijing 100035China Department of Pathology Beijing Jishuitan HospitalCapital Medical UniversityBeijing 100035China

Objective The Vickers ligament is thought to hinder the growth of palmar ulnar radius by tethering the lunate to the radius,leading to Madelung *** purpose of this study was to clarify the nature of the Vickers ligament and investigate its pathogenesis in Madelung deformities based on our observation of the Vickers *** All 22 patients(33 wrists)with Madelung deformities treated surgically between 2018 and 2022 were *** diagnosis was confirmed radiographically in all *** three-dimensional computed tomography(3D-CT)data of 16 patients(19 wrists)were *** resonance imaging(MRI)data were available for 9 patients(14 wrists).Wrist arthroscopy was used in 4 *** Vickers ligament was resected and submitted for histopathological examination in 8 *** outcomes,3D-CT,MRI,arthroscopy,surgical findings,and histopathology of the Vickers ligament were *** The 3D-CT revealed that the Vickers ligament originated in the metaphysis and formed a metaphyseal defect at the palmar ulnar *** the sequential MR coronal images,the Vickers ligament could be divided into 3 branches,extending to the lunate,triquetrum and ulnar *** and surgical findings revealed that the nature of the Vickers ligament was the stretched palmar ligament of the *** histopathology results revealed ligamentous tissue and fibrocartilaginous metaplasia with a structure similar to that of the triangular fibrocartilage complex(TFCC).Conclusions The Vickers ligament is not a separate aberrant *** nature of the Vickers ligament is a combination of the stretched TFCC ligament(palmar radioulnar ligament,ulnotriquetral ligament and ulnolunate ligament)and radiolunate *** possible pathogenesis of Madelung deformity might be focal early epiphyseal closure at the middle part of the sigmoid notch,which leads to focal growth retardation of the radius and pulls palmar ligaments proximally to for

关键词： Vickers ligament Madelung deformity pathogenesis computed tomography magnetic resonance imaging