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Promoting electrocatalytic nitrogen reduction to ammonia via dopant boron on two-dimensional materials

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Rare Metals 2024年第10期43卷 5117-5125页

作者： Ya-Hui Cui Wen-cheng Ouyang Ai-Jun Gao Chang-yuan yu Li-Peng Zhang State Key Laboratory of Organic-Inorganic Composites College of Chemical EngineeringBeijing University of Chemical Technology College of Materials Science and Engineering Beijing University of Chemical Technology College of Life Science and Technology Beijing University of Chemical Technology

Electrocatalytic nitrogen reduction reaction(NRR) is a key process for producing energy efficient and environment friendly ammonia. Boron-doped two-dimensional materials are highly promising as NRR ***, the interaction between doped boron and matrix materials on NRR catalytic performance is still unclear,which is limiting the development of catalysts containing boron for NRR. Here, NRR on different boron-doped twodimensional(2D) materials was explored by first principle theory. It is found that adsorption energy of intermediate*NNH(E*NNH) can be used as a descriptor to characterize the catalytic activity for NRR. Boron-adsorbed black phosphorus(B-BP) is demonstrated showing excellent NRR catalytic activity and suppressing hydrogen evolution reaction. It is disclosed that the excellent catalytic performance of boron-doped structures comes from a proper quantitatively electron transfer(0.8e) between nitrogen in*NNH and the active site boron atom. This work not only established a descriptor for NRR catalytic activity on B-doped 2D materials, but also screened out a potential NRR catalyst. More importantly, the intrinsic reason and mechanism of high catalytic activity of boron-doped structures were proposed. This work provides a design principle for exploring high-performance NRR electrocatalysts containing boron.

关键词： Boron-doped two-dimensional materials Density functional theory Descriptor Electrocatalytic nitrogen reduction reaction

教育数字化赋能受教育权:时代内涵、法律风险与规制

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中国教育学刊 2024年第4期 44-50页

作者：陈鹏于茜兰陕西师范大学教育学部陕西西安710062

教育数字化赋能受教育权是数字化时代教育法治的变革与回应。受教育者的教育平等权、教育资源权、教育选择权、资格证书权、公正评价权在教育数字化时代被赋予新的时代内涵。新情形下,受教育权的保障存在法律正义、法律伦理和法律救济... 详细信息

教育数字化赋能受教育权是数字化时代教育法治的变革与回应。受教育者的教育平等权、教育资源权、教育选择权、资格证书权、公正评价权在教育数字化时代被赋予新的时代内涵。新情形下,受教育权的保障存在法律正义、法律伦理和法律救济等风险。对此,应加快并完善教育数字化法治进程:以受教育权保障为根本宗旨,厘清国家义务;以彰显育人功能为价值原则,廓清伦理边界;以法律法规与行业标准为依托,共筑调控体系。

关键词：教育数字化受教育权法律风险法律规制

Role of adaptation measures in addressing heatwave exposure in China

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Advances in Climate Change Research 2024年第1期15卷 148-157页

作者： Qin-Mei HAN Qing-chen CHAO Shao SUN Pei-Jun SHI National Climate Centre China Meteorological AdministrationBeijing 100081China State Key Laboratoryof Severe Weather Chinese Academy of Meteorological Sciences Beijing 0o08lChina Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China

Heatwave exposure has increased dramatically because of climate warming and population growth,along with their interactive ***,effective adaptation measures can reduce these ***,the dynamic changes,regional inequality in adaptive capacity and their potential contributions to reducing exposure in the future remain *** study quantifies the impact of adaptive capacity and underscores regional variations in heatwave magnitudes,population exposure and adaptation levels in *** projected the future adaptive capacity using air-conditioner penetration,factoring in climate cooling requirements and individuals'purchasing *** population and gross domestic product(GDP)data from four Shared Socioeconomic Pathways(SSP1,SSP2,SSP3 and SSP5)and daily temperature data from four SSP-based emission scenarios(SSP1-2.6,SSP2-4.5,SSP3-7.0 and SSP5-8.5),we estimated heatwave duration,population exposure and avoided impacts through adaptation across China and its *** show a substantial increase in heatwave duration in Southwest and Southern China,especially under the SSP5-8.5 scenario,with a projection of 163.2±36.7 d during *** the SSP3|SSP3-7.0 scenario,total exposure reaches 156.4±76.8 billion person d per year,which is the highest among all scenarios and 23 times greater than that in 1986-2005 without *** considering adaptation measures,a noteworthy reduction in population exposure is observed,especially in the SSP3|SSP3-7.0 and SSP5JSSP5-8.5 scenarios,with reductions of(62.6±3.9)%and(65.8±5.1)%,respectively,compared with the scenario without adaptation during *** regional disparities in avoided impacts are also evident,with variations of up to 50%across different *** implementation of effective and environmentally friendly adaptation measures can notably address climate change,thereby alleviating the profound threats posed to human well-being.

关键词： Heatwaves Population exposure Adaptation Future projection China

Experimental investigation on using CO_(2)/H_(2)O emulsion with high water cut in enhanced oil recovery

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Petroleum Science 2024年第2期21卷 974-986页

作者： Xi-Dao Wu Peng Xiao Bei Liu Guang-Jin chen Jian-Hua Pang State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Ocean Intelligence Technology Center Shenzhen Institute of Guangdong Ocean UniversityShenzhen518120GuangdongChina

CO_(2) emulsions used for EOR have received a lot of interest because of its good performance on CO_(2)mobility ***,most of them have been focusing on the high quality CO_(2) emulsion(high CO_(2) fraction),while CO_(2) emulsion with high water cut has been rarely *** this paper,we carried out a comprehensive experimental study of using high water cut CO_(2)/H_(2)O emulsion for enhancing oil ***,a nonionic surfactant,alkyl glycosides(APG),was selected to stabilize CO_(2)/H_(2)O emulsion,and the corresponding morphology and stability were evaluated with a transparent PVT ***,plugging capacity and apparent viscosity of CO_(2)/H_(2)O emulsion were measured systematically by a sand pack displacement apparatus connected with a 1.95-m long capillary ***,a high water cut(40 vol%) CO_(2)/H_(2)O emulsion was selected for flooding experiments in a long sand pack and a core sample,and the oil recovery,the rate of oil recovery,and the pressure gradients were *** results indicated that APG had a good performance on emulsifying and stabilizing CO_(2) *** inversion from H_(2)O/CO_(2) emulsion to CO_(2)/H_(2)O emulsion with the increase in water cut was ***_(2)/H_(2)O emulsions with lower water cuts presented higher apparent viscosity,while the optimal plugging capacity of CO_(2)/H_(2)O emulsion occurred at a certain water ***,the displacement using CO_(2)/H_(2)O emulsion provided 18.98% and 13.36% additional oil recovery than that using pure CO_(2) in long sand pack and core tests,*** work may provide guidelines for EOR using CO_(2) emulsions with high water cut.

关键词： CO_(2)/H_(2)O emulsion High water cut CO_(2) mobility control Enhanced oil recovery

Deep learning for joint channel estimation and feedback in massive MIMO systems

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Digital Communications and Networks 2024年第1期10卷 83-93页

作者： Jiajia Guo Tong chen Shi Jin Geoffrey Ye Li Xin Wang Xiaolin Hou National Mobile Communications Research Laboratory Southeast UniversityNanjing210096China Department of Electrical and Electronic Engineering Imperial College LondonLondonSW72AZUK DOCOMO Beijing Communications Laboratories Co. LtdBeijingChina

The great potentials of massive Multiple-Input Multiple-Output(MIMO)in Frequency Division Duplex(FDD)mode can be fully exploited when the downlink Channel State Information(CSI)is available at base ***,the accurate CsI is difficult to obtain due to the large amount of feedback overhead caused by massive *** this paper,we propose a deep learning based joint channel estimation and feedback framework,which comprehensively realizes the estimation,compression,and reconstruction of downlink channels in FDD massive MIMO *** networks are constructed to perform estimation and feedback explicitly and *** explicit network adopts a multi-Signal-to-Noise-Ratios(SNRs)technique to obtain a single trained channel estimation subnet that works well with different SNRs and employs a deep residual network to reconstruct the channels,while the implicit network directly compresses pilots and sends them back to reduce network *** module is also designed to generate data-bearing *** results show that the two proposed networks exhibit excellent performance of reconstruction and are robust to different environments and quantization errors.

关键词： Channel estimation CSI feedback Deep learning Massive MIMO FDD

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基于核心素养培育的高中音乐鉴赏教学研究

教育理论与实践 2024年第8期44卷 59-61页

作者：陈诗玉吴丽深圳市坪山高级中学广东深圳518118 山西省教育科学研究院山西太原030009

鉴赏教学是高中音乐课程体系的重要组成部分,是培养学生审美感知、艺术表现和文化理解等素养及能力的关键载体。高中音乐鉴赏教学对于培养学生的音乐学科核心素养具有重要的作用。高中音乐鉴赏教学要注重将音乐审美作为核心,培养学生的... 详细信息

鉴赏教学是高中音乐课程体系的重要组成部分,是培养学生审美感知、艺术表现和文化理解等素养及能力的关键载体。高中音乐鉴赏教学对于培养学生的音乐学科核心素养具有重要的作用。高中音乐鉴赏教学要注重将音乐审美作为核心,培养学生的音乐实践能力和音乐创造能力。在高中音乐鉴赏教学中,要注重加强高中音乐鉴赏教学与其他学科教学的结合;创设音乐欣赏情境,开展互动式教学;加强课程的实践性,构建生态课堂,增强学生的生命体验;鼓励学生自主创作,进行激励性评价,促进学生音乐学科核心素养的发展。

关键词：核心素养:高中音乐鉴赏教学欣赏情境课程实践自主创作

Dynamic 3D shape reconstruction under complex reflection and transmission conditions using multi-scale parallel single-pixel imaging

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Light(Advanced Manufacturing) 2024年第3期5卷 93-104页

作者： Zhoujie Wu Haoran Wang Feifei chen Xunren Li Zhengdong chen Qican Zhang School of Electronics and Information Engineering Sichuan UniversityChengduSichuan Province 610065China

Depth measurement and three-dimensional(3D)imaging under complex reflection and transmission conditions are challenging and even impossible for traditional structured light techniques,owing to the precondition of point-to-point *** recent progress in addressing this problem,there is still no efficient and general ***,a Fourier dual-slice projection with depth-constrained localization is presented to separate and utilize different illumination and reflection components efficiently,which can significantly decrease the number of projection patterns in each sequence from thousands to ***,multi-scale parallel single-pixel imaging(MS-PSI)is proposed based on the established and proven position-invariant theorem,which breaks the local regional assumption and enables dynamic 3D *** methodology successfully unveils unseen-before capabilities such as(1)accurate depth measurement under interreflection and subsurface scattering conditions,(2)dynamic measurement of the time-varying high-dynamic-range scene and through thin volumetric scattering media at a rate of 333 frames per second;(3)two-layer 3D imaging of the semitransparent surface and the object hidden behind *** experimental results confirm that the proposed method paves the way for dynamic 3D reconstruction under complex optical field reflection and transmission conditions,benefiting imaging and sensing applications in advanced manufacturing,autonomous driving,and biomedical imaging.

关键词： Computational imaging 3D shape reconstruction 3D imaging Single-pixel imaging Light transport coefficient

Ergodicity of a Special Class of Markov Chains

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Acta Mathematicae Applicatae Sinica 2024年

作者： Xin-yu HU Ping HE School of Mathematics Shanghai University of Finance and Economics

The paper focuses on the ergodicity of a φ-irreducible Markov chain {X_n, n ≥ 0} that is generated iteratively through the expression Xn+1= f（X_n） + ?n+1. Here, {?_n, n ≥ 1} is a sequence of independent identically distributed centralized random variables, f（·） is an R-valued continuous function, and X0is arbitrary but independent of {?_n, n ≥ 1}. Our main contribution is to provide necessary and sufficient conditions for ergodicity of this special class of Markov chains. We also present a generalized approach for f（·） in the end.

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The haplotype-resolved genome assembly of autotetraploid rhubarb Rheum officinale provides insights into its genome evolution and massive accumulation of anthraquinones

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Plant Communications 2024年第1期5卷 196-214页

作者： Hongyu Zhang Qiang He Longsheng Xing Ruyu Wang yu Wang yu Liu Qinghong Zhou Xuanzhao Li Zheng Jia Ze Liu yuqing Miao Tao Lin Wei Li Huilong Du School of Life Sciences Institute of Life Sciences and Green DevelopmentBasic Science Center for Biotic Interaction in HebeiHebei UniversityBaoding 071000China College of Horticulture China Agricultural UniversityNo.2 Yuanmingyuan West RoadHaidian DistrictBeijing 100193China

Rheum officinale,a member of the Polygonaceae family,is an important medicinal plant that is widely used in traditional Chinese ***,we report a 7.68-Gb chromosome-scale assembly of *** with a contig N50 of 3.47 Mb,which was clustered into 44 chromosomes across four homologous *** genomics analysis revealed that transposable elements have made a significant contribution to its genome evolution,gene copy number variation,and gene regulation and expression,particularly of genes involved in metabolite biosynthesis,stress resistance,and root *** placed the recent autotetraploidization of *** at~0.58 mya and analyzed the genomic features of its homol-ogous *** no dominant monoploid genomes were observed at the overall expression level,numerous allele-differentially-expressed genes were identified,mainly with different transposable element insertions in their regulatory regions,suggesting that they functionally diverged after *** genomics,transcriptomics,and metabolomics,we explored the contributions of gene family amplification and tetraploidization to the abundant anthraquinone production of ***,as well as gene expression patterns and differences in anthraquinone content among *** report of-fers unprecedented genomic resources for fundamental research on the autopolyploid herb *** and guidance for polyploid breeding of herbs.

关键词： Rheum officinale genomics comparative genomics polyploid anthraquinone biosynthesis