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Acta Mechanica Solida Sinica 2024年第4期37卷 590-597页

作者： Junyu Tao Fan Zhang Jianyuan Zhang weijin Chen Yue Zheng School of Materials Shenzhen Campus of Sun Yat-sen UniversityShenzhen518107China Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices School of PhysicsSun Yat-sen UniversityGuangzhou510275China State Key Laboratory of Optoelectronic Materials and Technologies School of PhysicsSun Yat-sen UniversityGuangzhou510275China Centre for Physical Mechanics and Biophysics School of PhysicsSun Yat-sen UniversityGuangzhou510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai519082China

The flexoelectric effect describes the interplay between material polarization and strain *** much research has focused on control strategies for flexoelectricity,the impact of ferroelectric domain structure on the flexoelectric effect remains *** phase field simulations,we conduct a comparative study on the flexoelectric response of two types of BaTiO_(3)–SrTiO_(3) binary films:BaTiO_(3)–SrTiO_(3) multilayers and(Ba,Sr)TiO_(3) solid *** findings reveal that the flexoelectric response of these two systems,at the same Ba/Sr ratio,differs not only in magnitude but also in other aspects like temperature dependence,linearity,and hysteresis,due to their different ferroelectric domain structures and evolution *** study deepens our current understanding of flexoelectricity in ferroelectrics and suggests“domain engineering”as a potential way to tailor this effect.

关键词： Ferroelectric Flexoelectricity Multilayers Solid solution Phase field

Fluidization stability and periodic fluctuations in gas–solid separation fluidized bed using Geldart A dense medium

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Particuology 2024年第7期90卷 522-534页

作者： weijin Liu Dan Wang Liang Dong Enhui Zhou Tatiana Aleksandrova Chenyang Zhou Chenlong Duan Key Laboratory of Coal Processing and Efficient Utilization(China University of Mining&Technology) Ministry of EducationXuzhou 221116China School of Chemical Engineering&Technology China University of Mining&TechnologyXuzhou 221116China Department of Chemical and Biochemical Engineering The University of Western OntarioLondonOntario N6A 5B9Canada Mineral Processing Department Saint Petersburg Mining UniversitySt.Petersburg 199106Russia

Gas–solid separation fluidized bed is a typical method for coal separation without water *** A particles is also considered as the ideal dense medium to strengthen separation *** stability reflects the bed pressure fluctuations and the distribution of bubble and emulsion phases,affecting the separation *** the main frequency of pressure fluctuations can directly reflect the degree of pressure ***,the detailed fluidization stability is analyzed combined the method of standard deviation of pressure fluctuations,power spectral density,etc.,for Geldart A *** results showed that maintaining an appropriate gas velocity resulted in an average bed pressure of around 2000 *** main frequency is mainly concentrated around 1–1.5 ***,a prediction model of the main frequency of pressure fluctuations is established,and the error can be controlled within±*** investigation further proved the stable fluidization of Geldart A particles and provides a method for predicting the main frequency of pressure fluctuations in the gas–solid separation fluidized bed.

关键词： Geldart A dense medium Fluidization stability Periodic fluctuations Pressure fluctuations frequency Gas–solid separation fluidized bed

Pd-Catalyzed Dienylation of Propargylic Esters Enabling Highly Stereoselective Synthesis of Danishefsky-Type Trisubstituted Dienes

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Chinese Journal of Chemistry 2024年第17期42卷 1993-1998页

作者： Chen Zhou Mengfu Dai Xiaoyu Yin Mingyue Zhang weijin Gu Liang-An Chen Jiangsu Collaborative Innovation Center of Biomedical Functional Materials Jiangsu Key Laboratory of New Power BatteriesSchool of Chemistry and Materials ScienceNanjing Normal UniversityNanjingJiangsu 210023China

The stereochemical synthesis of highly substituted Danishefsky-type dienes remains unsolved in organic *** describe a simple and efficient approach for the stereoselective synthesis of Danishefsky-type trisubstituted dienes from readily available propargylic esters via Pd-catalyzed dienylation reaction through the key intermediate metallacyclobutene in a regio-,chemo-and stereoselective *** method facilitates a broad range of challenging trisubstituted dienes with a high level of stereocontrol.

关键词： Propargylic ester Dienylation Diene Stereoselectivity Cycloaddition Palladium β-H elimination Regioselectivity

Tuning the electronic conductance of REH_(x)(RE=Nd,Ce,Pr)by structural deformation

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Journal of Energy Chemistry 2024年第8期95卷 440-445,I0010页

作者： Shangshang Wang weijin Zhang Jirong Cui Shukun Liu Hong Wen Jianping Guo Teng He Hujun Cao Ping Chen Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023LiaoningChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Catalysis Chinese Academy of SciencesDalian 116023LiaoningChina

Hydride ion(H-)conductors have drawn much attention due to their potential applications in hydrideion-based *** earth metal hydrides(REH_(x))have fast H-conduction which,unfortunately,is accompanied by detrimental electron conduction preventing their application as ion ***,REH_(x)(RE=Nd,Ce,and Pr)with varied grain sizes,rich grain boundaries,and defects have been prepared by ball milling and subsequent *** electronic conductivity of the ball-milled REH_(x)samples can be reduced by 2-4 orders of magnitude compared with the non-ball-milled *** relationship of electron conduction and miscrostructures in REH_(x)is studied and discussed based on experimental data and previously-proposed classical and quantum *** H-conductivity of all REH_(x)is about 10^(-4)to 10^(-3)S cm^(-1)at room temperature,showing promise for the development of H-conductors and their applications in clean energy storage and conversion.

关键词： Hydride ion conduction Electron conduction Nanosized grain Crystal defect Electron scattering

Reducing the vacancies associated with ferroelectric polarization to promote photocatalytic overall water splitting

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Science China Chemistry 2024年第10期67卷 3258-3264页

作者： Haozhi Qi Yuyang Kang Jian-An Liu Lichang Yin Wenyu Zhang Shangyi Ma Jianhang Qiu Lingli Li weijin Hu Lianzhou Wang Gang Liu Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Nanomaterials Centre School of Chemical Engineering and Australian Institute for Bioengineering and NanotechnologyThe University of QueenslandSt LuciaBrisbane QLD 4072Australia

Ferroelectric materials hold great promise in photocatalytic water splitting because their built-in electric field induced by the depolarization field can fulfill the separation of photogenerated ***,a number of intrinsic charged vacancy defects are simultaneously generated to screen the depolarized field for stabilizing the crystal structure,always resulting in severe recombination of photogenerated carriers and thus poor overall water splitting ***,we proposed a strategy to promote the separation and transport of photogenerated carriers of ferroelectric photocatalysts by adjusting the ferroelectric polarization and altering the coordination environment of elements to reduce the defect ***,we prepared a series of Ta-doped PbTiO_(3)with low Pb(V_(Pb))and O(V_(O))vacancy concentrations by reducing the polarization intensity and strengthening the Pb–O *** Ta-doped PbTiO_(3)shows efficient charge separation and greatly enhanced photocatalytic overall water splitting activity with the assistance of *** work highlights the importance of regulating ferroelectric polarization and vacancy defect concentration by the doping strategy in charge separation for photocatalytic water splitting.

关键词： PbTiO_(3) ferroelectric polarization vacancy defect element doping photocatalytic overall water splitting

Land use and cover change and influencing factor analysis in the Shiyang River Basin,China

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Journal of Arid Land 2024年第2期16卷 246-265页

作者： ZHAO Yaxuan CAO Bo SHA Linwei CHENG Jinquan ZHAO Xuanru GUAN weijin PAN Baotian Key Laboratory of Western China's Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730030China Shiyang River Basin Scientific Observing Station Lanzhou UniversityLanzhou 730030China

Land use and cover change(LUCC)is the most direct manifestation of the interaction between anthropological activities and the natural environment on Earth's surface,with significant impacts on the environment and social *** economic development and climate change have resulted in significant changes in land use and *** Shiyang River Basin,located in the eastern part of the Hexi Corridor in China,has undergone significant climate change and LUCC over the past few *** this study,we used the random forest classification to obtain the land use and cover datasets of the Shiyang River Basin in 1991,1995,2000,2005,2010,2015,and 2020 based on Landsat *** validated the land use and cover data in 2015 from the random forest classification results(this study),the high-resolution dataset of annual global land cover from 2000 to 2015(AGLC-2000-2015),the global 30 m land cover classification with a fine classification system(GLC_FCS30),and the first Landsat-derived annual China Land Cover Dataset(CLCD)against ground-truth classification results to evaluate the accuracy of the classification results in this ***,we explored and compared the spatiotemporal patterns of LUCC in the upper,middle,and lower reaches of the Shiyang River Basin over the past 30 years,and employed the random forest importance ranking method to analyze the influencing factors of LUCC based on natural(evapotranspiration,precipitation,temperature,and surface soil moisture)and anthropogenic(nighttime light,gross domestic product(GDP),and population)*** results indicated that the random forest classification results for land use and cover in the Shiyang River Basin in 2015 outperformed the AGLC-2000-2015,GLC_FCS30,and CLCD datasets in both overall and partial ***,the classification results in this study exhibited a high level of agreement with the ground truth *** 1991 to 2020,the area of bare land exhibited a decreasing trend,with chan

关键词： land use and cover classification land use and cover change(LUCC) climate change random forest accuracy assessment three-dimensional sampling method Shiyang River Basin

NURBS reconstruction of digital terrain for hydropower engineering based on TIN model

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Progress in Natural Science:Materials International 2008年第11期18卷 1409-1415页

作者： Denghua Zhong Jie Liu Mingchao Li Caiwei Hao School of Civil Engineering,Tianjin University,92 weijin road,Nankai District,Tianjin 300072,China School of Civil Engineering Tianjin University 92 Weijin Road Nankai District Tianjin 300072 China

Digital terrain model(DTM)has played an important role in 3D designing,visual analysis and 3D geological modeling in large-scale hydropower *** the pivotal base of 3D visualization and modeling,DTM should be characterized by high precision,less storage and well interactivity during graphic *** the diversity of data source and taking advantage of two data structures, triangulated irregular network(TIN)and non-uniform rational B-splines(NURBS),a novel methodology is presented for reconstructing engi- neering terrain ofhydropower *** integration of multi-source data,enhanced Delaunay algorithm is introduced to rebuild the TIN DTM,which is a terrain surface in TIN and a faithful depiction of complex topography but in low-memory *** on the TIN model, applying section scanning sampling and linear interpolation,the transformation from discrete,irregular and diverse data to continuous and regular sampling cross-sectional curve sequence,is *** appropriate compression of the sampling data is also imposed to be performed for guaranteeing the following reconstruction ***,employing the NURBS technique and skinning method,the NURBS DTM, which represents a NURBS surface and satisfies the requirement after precision assess with weighted errors,is reconstructed with the inter- mediate ***,there is another achievement that two databases of terrain data,one from initial data and the other from sampling data,are established for repeatable reconstruction with different *** the successful application of the presented method,a stable foundation is laid for 3D engineering geological modeling,visual designing and analysis of the hydropower projects.

关键词： Terrain reconstruction TIN NURBS Data compression Weighted error Hydropower engineering

新中国成立前后刘少奇关于工会工作的认识和思考

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党的文献 2024年第1期 68-74页

作者：覃伟津黄坤华南理工大学马克思主义学院广东广州510641

新中国成立前后,刘少奇根据形势变化,紧紧围绕党的中心工作,对做好工会工作、更好发挥工会作用,进行了深入思考和积极探索。他强调工会工作的重要性,指出领导城市工作必须依靠工会,建设新中国也必须充分发挥工会的作用;强调工会工作的... 详细信息

新中国成立前后,刘少奇根据形势变化,紧紧围绕党的中心工作,对做好工会工作、更好发挥工会作用,进行了深入思考和积极探索。他强调工会工作的重要性,指出领导城市工作必须依靠工会,建设新中国也必须充分发挥工会的作用;强调工会工作的政治性,指出“党应当加强对工会工作的领导”,要求通过在工会中建立党组等形式加强党对工会工作的领导,要求工会要自觉并善于取得党的领导;强调工会要保持先进性,认为“工会是共产主义学校”,要把提高工人的思想觉悟、政治素养摆在重要位置,要努力提高工人文化水平和生产技能,使其更好服务于党和国家工作大局;认为“工会是工人群众性的组织”,指出工会的基础在工人群众,要站稳群众立场,努力为工人群众谋福祉。刘少奇的这些认识和思考,为我国工会工作的蓬勃发展提供了科学指导,也为我们在新征程上进一步做好工会工作提供了深刻启示。

关键词：新中国成立刘少奇工会工作党的领导群众路线

外侧楔形鞋垫对足踝生物力学影响的有限元分析

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医用生物力学 2024年第3期39卷 469-475页

作者：杜玮瑾陈维毅郭媛太原理工大学生物医学工程学院太原030024

目的探究外侧楔形鞋垫对足踝内部组织(包括足骨、关节和韧带)的生物力学影响。方法建立并验证足踝-鞋垫-地面三维有限元模型,探究步态3个关键瞬间赤足模型和鞋垫干预模型的足底压力分布、关节接触压力、跖骨及主要韧带的应力。结果 5... 详细信息

目的探究外侧楔形鞋垫对足踝内部组织(包括足骨、关节和韧带)的生物力学影响。方法建立并验证足踝-鞋垫-地面三维有限元模型,探究步态3个关键瞬间赤足模型和鞋垫干预模型的足底压力分布、关节接触压力、跖骨及主要韧带的应力。结果 5°外侧楔形鞋垫模型足底峰值压力比赤足模型减小65.8%。鞋垫干预使楔舟关节处峰值接触压力减小;距下关节处峰值接触压力和第4、5跖骨处峰值应力增大。结论本研究量化评估了外侧楔形鞋垫对足踝各部分的生物力学影响,提出了可适当减小外侧楔形鞋垫第4、5跖骨处倾斜角度的设计建议。

关键词：外侧楔形鞋垫足底压力分布关节接触压力有限元分析生物力学

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