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In situ construction of Cu(Ⅰ)-Cu(Ⅱ) pairs for efficient electrocatalytic nitrate reduction reaction to ammonia

Journal of Energy Chemistry 2025年第1期100卷 106-113页

作者： Muyun Zheng Yuchi Wan Leping Yang Shen Ao Wangyang Fu Zhengjun Zhang Zheng-Hong Huang Tao Ling Feiyu Kang Ruitao Lv State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Institute of New Energy Materials and Engineering School of Materials Science and EngineeringFuzhou UniversityFuzhou 350108FujianChina Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China Key Laboratory for Advanced Ceramics and Machining Technology of ministry of education Tianjin Key Laboratory of Composite and Functional MaterialsSchool of Materials Science and EngineeringTianjin UniversityTianjin 300072China

Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution *** report a CuO nanoparticles incorporated on nitrogen-doped porous carbon (CuO@NC) catalyst for NO_(3)-*** of Cu(Ⅱ) is reduced to Cu(Ⅰ) during the NO_(3)-RR process to construct Cu(Ⅰ)-Cu(Ⅱ) pairs,confirmed by in situ X-ray photoelectron spectroscopy (XPS) and Raman *** functional theory (DFT) calculations indicated that the formation of Cu(Ⅰ) could provide a reaction path with smaller energy barrier for NO_(3)-RR,while Cu(Ⅱ) effectively suppressed the competition of hydrogen evolution reaction (HER).As a result,CuO@NC catalyst achieved a Faradaic efficiency of 84.2% at -0.49 V versus reversible hydrogen electrode (RHE),and a NH_(3)yield rate of 17.2 mg h^(-1)mg^(-1)*** -0.79 V ***,higher than the HaberBosch process (<3.4 g h^(-1)g^(-1)cat.).This work may open a new avenue for effective NO_(3)-RR by modulating oxidation states.

关键词： Ammonia synthesis Cu oxidation state Electrochemistry Nitrate reduction In situ XPS

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Bone marrow mesenchymal stem cells promote uterine healing by activating the PI3K/AKT pathway and modulating inflammation in rat models

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World Journal of Stem Cells 2025年第1期17卷 22-39页

作者： Jing Yang Jun Yuan Yan-Qing Wen Li Wu Jiu-Jiang Liao Hong-Bo Qi Women and Children’s Hospital of Chongqing Medical University Chongqing 401147China Chongqing Key Laboratory of Maternal and Fetal Medicine Chongqing Medical UniversityChongqing 400016China Obstetrics and Gynecology Guizhou Provincial People’s HospitalGuiyang 557300Guizhou ProvinceChina Research Laboratory of Reproduction and Development of Chinese ministry of education Chongqing Medical UniversityChongqing 400016China

BACKGROUND Uterine injury can cause uterine scarring,leading to a series of complications that threaten women’s *** healing is a complex process,and there are currently no effective *** our previous studies have shown that bone marrow mesenchymal stem cells(BMSCs)promote uterine damage repair,the underlying mechanisms remain ***,exploring the specific regulatory roles of BMSCs in uterine injury treatment is crucial for further understanding their functions and enhancing therapeutic *** To investigate the underlying mechanism by which BMSCs promote the process of uterine *** In in vivo experiments,we established a model of full-thickness uterine injury and injected BMSCs into the uterine *** sequencing was per-formed to determine the enrichment of differentially expressed genes at the wound *** in vitro experiments,we isolated rat uterine smooth muscle cells(USMCs)and cocultured them with BMSCs to observe the interaction between BMSCs and USMCs in the *** We found that the differentially expressed genes were mainly related to cell growth,tissue repair,and angiogenesis,while the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)pathway was highly *** reverse-transcription polymerase chain reaction was used to validate differentially expressed genes,and the results demonstrated that BMSCs can upregulate genes related to regeneration and downregulate genes related to *** BMSCs promoted the migration and proliferation of USMCs,and the USMC microenvironment promoted the myogenic differentiation of ***,we validated the PI3K/AKT pathway in tissues and cells and showed that BMSCs activate the PI3K/AKT pathway to promote the regeneration of uterine smooth muscle both in vivo and in *** BMSCs upregulated uterine wound regeneration and anti-inflammatory factors and enhanced uterine smooth muscle proliferation throu

关键词： Uterine injury Bone marrow mesenchymal stem cells Uterine smooth muscle cells Phosphoinositide 3-kinase/protein kinase B pathway Cell-cell interactions Cell proliferation Immune regulation Wound regeneration

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Dynamic Modeling of a Novel Multi-Loop Multi-Body Mechanism of Face-Shovel Excavator

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Chinese Journal of Mechanical Engineering 2025年第1期38卷 323-339页

作者： Jisong Ding Huafeng Ding Wenjian Yang School of Mechanical Engineering and Electronic Information China University of Geosciences(Wuhan)Wuhan 430074China

Currently,research in multi-body dynamics predominantly focuses on symmetric parallel mechanisms with multiple ***,for the working mechanism(WM)of a face-shovel hydraulic excavator,an asymmetric mechanism with multiple closed loops,there is a significant lack of research on dynamic models that account for the mass and inertia of all its moving *** main focus of this study is to research a dynamic model of multi-closed-loop multi-body planar mechanism considering all moving *** paper introduces a novel WM for a face-shovel excavator,featuring 4 loops and 12 *** loop decomposition,the kinematic equations of the 11 primary moving components of the WM,including position,velocity,angular velocity,acceleration,and angular acceleration,are accurately *** comparative analysis,a simplified dynamic model of WM was established,considering only the boom,stick,and *** complete dynamic models based on the virtual work principle were also *** correctness of both the simplified and complete dynamic models was verified through numerical simulations in Adams software.A comparison of simplified and complete dynamic simulation results shows that the new complete dynamic model has the advantage of *** research proposes a kinematic and dynamic modeling method with reference significance for the kinematic and dynamic analysis of planar complex multi-loop mechanisms,laying a foundation for performance analysis and the design of excavator WMs.

关键词： Hydraulic face-shovel excavator Dynamic Kinematic Planer multi rigid body mechanism Virtual work

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Statistical Research on Megahertz-peaked Spectra Pulsars

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Research in Astronomy and Astrophysics 2025年第1期25卷 116-134页

作者： Hong-Bing Cai Li Chen Shi-Dang Li Kai Wang Hang Liu JSNU SPBPU Institute of Engineering & SINO RUSSIAN Institute Jiangsu Normal University School of Physics and Electronic Engineering Jiangsu Normal University

Megahertz-peaked spectra(MPS) pulsars are referred as cases whose radio spectra turn over around 100 MHz. We identified 53 MPS pulsars based on the spectral data from the literature, and statistically analyzed the spatial location distribution, the magnetic field-period distribution, peak frequencies, spectral indices, and dispersion measures of these MPS pulsars. We found that there is a strong positive correlation between the dispersion measures and the peak frequencies of MPS pulsars, and negative correlations of the dispersion measures with spectral indices and the ages are also found. Such correlations suggest that the interstellar medium is an important factor that affects observational properties of MPS pulsars.

关键词： (stars:) pulsars: general ISM: general radio continuum: general

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Properties of diffuse and volume discharges that are important for their applications

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High Voltage 2025年第1期10卷 126-136页

作者： Victor Tarasenko Alexei Panchenko Dmitry Beloplotov Mikhail Lomaev Dmitry Sorokin Cheng Zhang Institute of High Current Electronics Siberian BranchRussian Academy of ScienceTomskRussia Beijing International S&T Cooperation Base for Plasma Science and Energy Conversion Institute of Electrical EngineeringChinese Academy of SciencesBeijingChina

Diffuse and volume discharges are currently used widely in various *** work compares the properties of diffuse and volume discharges,as well as considers the conditions for their formation at high *** main attention is paid to a diffuse discharge(DD).It has been shown that the ignition of a diffuse discharges is preceded by the development of a wide *** the case of a volume discharge,the streamers usually have a small diameter and an ionisation waves emerging from it passes into the spark leader with subsequent discharge *** are images and emission spectra of diffuse discharges in air and nitrogen in the *** has been confirmed that a diffuse discharges initiated by a nanosecond voltage pulse in a point-to-plane gaps has a uniform effect on the surface of a flat *** was found that thin tracks of luminous particles are observed against the background of the DD plasma *** are asso-ciated with sputtering of the pointed electrode material due to the large field enhance-ment on the macro-and microinhomogeneities.

关键词： luminous subsequent initiated

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Performance Analysis for DAG-based Blockchain Systems Based on the Markov Process

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Journal of Systems Science and Systems Engineering 2025年第1期34卷 29-54页

作者： Xingshuo Song Shiyong Li Yanxia Chang Chi Zhang Quanlin Li School of Economics and Management Yanshan UniversityQinhuangdao066004China School of Economics and Management Bering University of TechnologyBeijing100124China

As an innovative approach, Direct Acyclic Graph (DAG)-based blockchain is designed to overcome the scalability and performance limitations of traditional blockchain systems, which rely on sequential structures. The graph-based architecture of DAG allows for faster transactions and parallel processing, making it a compelling option across various industries. To enhance the analytical understanding of DAG-based blockchains, this paper begins by introducing a Markov model tailored for a DAG-based blockchain system, specifically focusing on the Tangle structure and the interaction between tips and newly arrived transactions. We then establish a continuous-time Markov process to analyze the DAG-based blockchain, demonstrating that this process is a level-dependent quasi-birth-and-death (QBD) process. We further prove that the QBD process is both irreducible and positively recurrent. Building on this foundation, we conduct a performance analysis of the DAG-based blockchain system by deriving the stationary probability vector of the QBD process. Notably, we introduce a novel method to calculate the average sojourn time of any arriving internal tip within the system using first passage times and Phase-type (PH) distributions. Finally, numerical examples are provided to validate our theoretical findings and to illustrate the influence of system parameters on the performance metrics.

关键词： Blockchain direct acyclic graph(DAG) QBD process performance analysis sojourn time

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Health communication strategies in the digital era:Insights from the Paris Olympics

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Journal of Sport and Health Science 2025年第1期14卷 61-63页

作者： Yijun Chen School of Journalism and Communication Shanghai UniversityShanghai 200072China

*** Sports mega-events should transcend mere celebrations and generate lasting societal ***“post-Olympic”era legacies often become focal points of global interest.1,2 As the apex of international multi-sport events,the Olympics offer an unparalleled opportunity to shift societal health *** spectators are motivated to engage in sports and elevate their understanding of athletics through the event,it constitutes the Olympics’most significant legacy.3 The 2024 Paris Olympics emerged as a global showcase for pioneering health communication strategies,utilizing digital media to advance physical fitness and sports *** article delves into the digital health communication strategies employed during the Paris Olympics and proposes policy recommendations to amplify global public health benefits.

关键词： sports knowledge shift societal health behaviorswhen health communication digital media public health benefits Olympic legacy

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FDNet:Fourier transform guided dual-channel underwater image enhancement diffusion network

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Science china(Technological Sciences) 2025年第1期68卷 58-74页

作者： Zhen ZHU Xiaobo LI Qianwen MA Jingsheng ZHAI Haofeng HU School of Marine Science and Technology Tianjin UniversityTianjin 300072China College of Mechanical Engineering and Automation Fuzhou UniversityFuzhou 350108China

Due to the scattering and absorption of light,underwater imaging yields suboptimal results characterized by low brightness,diminished image contrast,and the loss of *** learning-based underwater image enhancement(UIE)methods mainly focus on addressing these issues in the spatial domain,with limited attention to the Fourier frequency *** propose the Fourier transform guided dual-channel underwater image enhancement diffusion network(FDNet),aiming to fully leverage frequency domain information and the characteristics of a diffusion-based generation *** amplitude-phase dualchannel not only effectively provides feedback on the energy distribution of the image but also incorporates crucial image structure and texture *** on these advantages,we first introduce a Fourier transform-based amplitude-phase dualchannel enhancement front-end network for *** network significantly improves the quality of the network's image input,including brightness and contrast,by incorporating phase congruency edge enhancement and prior-driven amplitude mapping *** preceding network mitigates the overall training challenges caused by poor input image ***,the application of denoising networks based on lightweight transformers effectively improves the computational time required for each iteration during model *** results indicate that FDNet outperforms many current learning-based UIE algorithms in restoring images across multiple real underwater image datasets,demonstrating more robust generalization capabilities in degraded underwater *** competitive performance advantage achieved in enhancing visual quality underscores the effectiveness of our method.

关键词： underwater image enhancement Fourier transform deep neural network phase congruency diffusion model

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Elevational variation in anatomical traits of the first-order roots and their adaptation mechanisms

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Plant Diversity 2025年第2期47卷 291-299页

作者： Xue Wang Xinrui Liu Shuang Chen Jiang Zhu Yanqi Yuan Rong Zhu Kaixi Chen Xue Yang Xiaochun Wang Weiyi Mo Ruili Wang Shuoxin Zhang College of Forestry Northwest A&F UniversityYangling 712100ShaanxiChina Qinling National Forest Ecosystem Research Station HuoditangNingshan 711600ShaanxiChina

Root anatomical traits play an important role in understanding the link between root physiological function and ecological *** determine how plants change root anatomical traits to adapt to distinct environments,we measured four key root anatomical traitsdstele diameter(SD),cortex thickness(CT),root diameter(RD),and the stele to root diameter ratio(SDRD)dof first-order roots of 82 species collected from different vegetation zones along a 2000 m altitudinal gradient on the northern slope of Taibai *** with other altitudes,plants located in temperate birch and fir forests had thinner SD,CT,RD,and *** found that elevational variation in root anatomical traits could largely be explained by phylogenetic taxonomy(clade).In addition,changes in SD were driven by soil bulk density,whereas variations in CT and RD were influenced by soil available *** phylogenetic factors were removed from our analysis,allometric relationships between RD and root anatomical traits(SD and CT)were observed across different *** study reveals the influence of phylogeny and environment on the elevational variation in root anatomical traits and further supports the allometric relationship between root anatomical traits(SD and CT)and *** findings enhance our understanding of the evolutionary and adaptive mechanisms of root anatomical structures,providing a basis for predicting how root anatomical traits respond to global changes.

关键词： Allometric relationship Altitude Phylogeny Root anatomical traits Stressful environment

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Gradient age-precipitation behavior induced by gradient nano-grain in Mg-Gd-Ag-Zr alloy

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Journal of Iron and Steel Research International 2025年第1期32卷 19-24页

作者： Bang-jun Li Jia-peng Sun Jing Han Guo-song Wu College of Materials Science and Engineering Hohai UniversityNanjing 210024JiangsuChina School of Mechanical and Electrical Engineering China University of Mining and TechnologyXuzhou 221116JiangsuChina

Gradient nano-grained structure is frequently engineered into metallic materials,including Mg alloys,to achieve superior combination of strength and ***,the influence of this microstructural feature on aging precipitation behavior remains inadequately *** this study,the age-precipitation behavior of a gradient nano-grained Mg-Gd-Ag-Zr alloy prepared via ultrasonic severe surface rolling was *** result indicates that the aging precipitation behavior exhibits a depth-dependent variation within this *** the nano-grained surface layer,hierarchicalβnano-precipitates are predominant,while at greater depths,the precipitates consist ofβnanoparticles located at grain boundaries,along with intragranularβ′andγ″*** formation ofβnano-precipitates deviates from the conventional precipitation behavior observed in Mg-Gd-Ag alloys,and is attributed to the high density of defects induced by the surface nano-grained *** finding advances our understanding of the precipitation behavior in the alloys with heterogeneous microstructure.

关键词： Mg alloy Gradient Precipitation Aging behavior Microstructure

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