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Exploring charge and spin fluctuations in infinite-layer cuprate SrCuO_(2)from a phonon perspective

Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 159-167页

作者： Xin Du Pei-Han Sun ben-Chao Gong Jian-Feng zhang Zhong-Yi Lu Kai Liu Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices Renmin University of ChinaBeijing 100872China Department of Physics School of ScienceJiangsu University of Science and TechnologyZhenjiang 212100China Institute of Physics Chinese Academy of SciencesBeijing 100190China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China

The infinite-layer cuprate ACu O_(2)(A=Ca,Sr,Ba)possesses the simplest crystal structure among numerous cuprate superconductors and can serve as a prototypical system to explore the unconventional *** on the first-principles electronic structure calculations,we have studied the electronic and magnetic properties of the infinite-layer cuprate SrCuO_(2)from a phonon *** find that interesting fluctuations of charges,electrical dipoles,and local magnetic moments can be induced by the atomic displacements of phonon modes in SrCuO_(2)upon the hole *** all optical phonon modes of SrCuO_(2)in the antiferromagnetic Néel state,only the A_(1g)mode that involves the full-breathing O vibrations along the Cu-O bonds can cause significant fluctuations of local magnetic moments on O atoms and dramatic charge redistributions between Cu and O ***,due to the atomic displacements of the A_(1g)mode,both the charge fluctuations on Cu and the electrical dipoles on O show a dome-like evolution with increasing hole doping,quite similar to the experimentally observed behavior of the superconducting T_(c);in comparison,the fluctuations of local magnetic moments on O display a monotonic enhancement along with the hole *** analyses indicate that around the optimal doping,there exists a large softening in the frequency of the A_(1g)phonon mode and a van Hove singularity in the electronic structure close to the Fermi level,suggesting potential electron-phonon *** work reveals the important role of the full-breathing O phonon mode playing in the infinite-layer SrCuO_(2),which may provide new insights in understanding the cuprate superconductivity.

关键词： first-principles calculations cuprate superconductors phonon charge and spin fluctuations

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Reinforcement of High Impact Polystyrene by Aramid Nanoparticle Fillers Prepared via an In situ Bottom-up Approach

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Chinese Journal of Polymer Science 2024年第8期42卷 1167-1176页

作者： Xiang-Jun Gong Zhi-Ping Zhao Chang-Mei Sun Ying zhang rong-Jun Qu Ying Wang School of Chemistry and Materials Science Ludong UniversityYantai 264025China

In this work,aramid nanoparticles(ANPs)were prepared in dimethyl formamide(DMF)solution containing high impact polystyrene(HIPS)via a bottom-up *** electron microscopy(TEM)images showed that the obtained ANPs were evenly distributed in the HIPS matrix without any *** composition of the ANPs,i.e.,poly(p-phenyl-p-phenylenediamine)(PPTA),was confirmed by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS)and X-ray diffractometer(XRD).The ANP/HIPS composites,obtained after ethanol precipitation,were added to neat HIPS as fillers to fabricate ANP/HIPS composite *** surface roughness and the glass transition temperature(T_g)of the sheets were characterized by atomic force microscope(AFM)and differential scanning calorimetry(DSC),*** with neat HIPS,the mechanical properties of the composite sheet were significantly improved,and the Young's modulus increased from 246.55 MPa to 2025.12 MPa,the tensile strength increased from 3.07 MPa to 29.76 MPa,and the toughness increased from 0.32 N/mm^2 to 3.92 N/mm^2,with an increase rate of 721%,869%and 1125%,***,the thermal stability of the composites improved with the increase in ANP content.

关键词： High impact polystyrene PPTA nanoparticle Reinforce Mechanical property

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Comparative analysis of the characteristics of outlet short circuit and winding insulation fault of distribution transformer and its preventive measures

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High Voltage 2024年第3期9卷 700-709页

作者： Richang Xian Yuyao Hu Bingqian zhang Qingyu rong Rujie Zhao Wei Wang Yang Guo Yunhao Li College of Electrical and Electronic Engineering Shandong University of TechnologyZiboChina State Grid of China Technology College JinanChina Shandong Huineng Electric Co. Ltd.ZiboChina

Outlet short circuit on the low-voltage(LV)side and winding inter-turn short circuit faults are hazardous to transformer *** investigate the formation mechanism of winding insulation faults of distribution transformer,ANSYS Maxwell was used to build a coupled magnetic field-circuit model with the same structural dimension as the actual distribution *** outlet short circuit and winding inter-turn insulation faults were set by using the voltage-controlled switch in the external circuit of the ***-sequently,the differences in the electromagnetic characteristics and the electrodynamic force distributions of the windings under three operating conditions,namely,nominal load,three-phase outlet short circuit on the LV side and inter-turn insulation failure were studied,*** results show that compared with the rated load,in the cases of outlet short circuit and inter-turn insulation faults,the amplitude of winding current in-creases by 20 and 50 times,the magnetic field strength grows by 20 and 17 times,and the electrodynamic force rises by 400 and 230 times,*** short circuit fault is more likely to cause the winding instability and deformation,and inter-turn short circuit fault can easily burn out winding ***,corresponding preventive measures were proposed.

关键词： fault characteristics winding

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Evolution of Biofilm and Its Effect on Microstructure of Mortar Surfaces in Simulated Seawater

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 234-243页

作者：荣辉 YU Chenglong 张颖 School of Materials Science and Engineering Tianjin Chengjian UniversityTianjin 300384China Tianjin Key Laboratory of Building Green Functional Materials Tianjin Chengjian UniversityTianjin 300384China

To explore the role of biofilm formation on the corrosion of marine concrete structures, we investigated the attachment of biofilm on mortar surfaces in simulated seawater and the influence of biofilm on the microstructure of mortar surfaces. The results show that the evolution of biofilm on mortar surfaces in simulated seawater is closely related to the corrosion suffered by the mortar, and the process of biofilm attachment and shedding is continuous and cyclical. It is found that the specimens in the absence of biofilm attachment are more severely eroded internally by the corrosive medium in simulated seawater than those in the presence of biofilm attachment. For the specimens without biofilm attachment, after 60 days, gypsum forms,and after 120 days, the number of pores in the mortar is reduced. In contrast, for the specimens in the presence of biofilm attachment, gypsum could only be detected after 90 days, and fewer pores are filled. Therefore, the formation of biofilm could delay the invasion of the corrosive medium into the interior of mortar during the evolution of biofilm on mortar surfaces, mitigating the corrosion of mortars in seawater.

关键词： biofilm attachment mortar sulfur-oxidizing bacteria gypsum simulated seawater microstructure

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Asymmetric Transfer Hydrogenation of Stable NH Imines for the Synthesis of Enantiopure α-Chiral Primary Amines

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Chinese Journal of Chemistry 2024年第18期42卷 2211-2216页

作者： Mangang zhang Hui Li Keqin Wu Nianxin rong Shaoquan Lin Hua Yang Qin Yin College of Chemistry and Chemical Engineering Central South UniversityChangshaHunan 410083China Faculty of Pharmaceutical Sciences Shenzhen University of Advanced TechnologyShenzhenGuangdong 518055China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhenGuangdong 518055China

Although it offers a direct route to access synthetically valuableα-chiral primary amines,asymmetric transfer hydrogenation of NH imines has been rarely studied,due in large part to the inaccessibility and instability of NH ***,we report a Rh-catalyzed asymmetric transfer hydrogenation of a kind of novel and stable NH imines which are prepared via condensation of easily available sulfonylated 2'-aminoacetophenones with NH3 in *** this method,enantioenriched chiral 2-(1-aminoalkyl)anilines,which are privileged pharmacore groups,have been synthesized with good functional group compatibility,and with up to 99%ee.A gram-scale reaction using 0.2 mol%of catalyst has been successfully performed to highlight the ***,the products can be derivatized into enantiopure bioactive molecules as well as chiral tridentate ligands for metal catalysis.

关键词： Asymmetric transfer hydrogenation Asymmetric hydrogenation α-Chiral primary amine NH imines 2-(1-Aminoalkyl)anilines

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Self-polarized RGB device realized by semipolar micro-LEDs and perovskite-in-polymer films for backlight applications

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Opto-Electronic Advances 2024年第3期7卷 35-49页

作者： Tingwei Lu Yue Lin Tianqi zhang Yue Huang Xiaotong Fan Shouqiang Lai Yijun Lu Hao-Chung Kuo Zhong Chen Tingzhu Wu rong zhang School of Electronic Science and Engineering Fujian Engineering Research Center for Solid-State LightingXiamen UniversityXiamen 361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China Department of Photonics and Graduate Institute of Electro-Optical Engineering College of Electrical and Computer EngineeringYang Ming Chiao Tung UniversityHsinchu 30010China Semiconductor Research Center Hon Hai Research InstituteTaipei 11492China.

In backlighting systems for liquid crystal displays,conventional red,green,and blue(RGB)light sources that lack polarization properties can result in a significant optical loss of up to 50%when passing through a *** address this inefficiency and optimize energy utilization,this study presents a high-performance device designed for RGB polarized *** device employs an array of semipolar blueμLEDs with inherent polarization capabilities,coupled with mechanically stretched films of green-emitting CsPbBr3 nanorods and red-emitting CsPbI3-Cs4PbI6 hybrid *** CsPbBr3 nanorods in the polymer film offer intrinsic polarization emission,while the aligned-wire structures formed by the stable CsPbI3-Cs4PbI6 hybrid nanocrystals contribute to substantial anisotropic emissions,due to their high dielectric *** resulting device achieved RGB polarization degrees of 0.26,0.48,and 0.38,respectively,and exhibited a broad color gamut,reaching 137.2%of the NTSC standard and 102.5%of the Rec.2020 *** compared to a device utilizing c-plane LEDs for excitation,the current approach increased the intensity of light transmitted through the polarizer by 73.6%.This novel fabrication approach for polarized devices containing RGB components holds considerable promise for advancing next-generation display technologies.

关键词： halide perovskite light-emitting-diodes polarized emission nanocrystals stability

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Revealing the Structure-Property Difference of Natural Rubber Prepared by Different Methods: Protein and Gel Content are Key Factors

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Chinese Journal of Polymer Science 2024年第4期42卷 457-467页

作者： Shao-Qi Huang Jun-Qi zhang Yong Zhu Ling-Min Kong Lu-Sheng Liao Fu-Quan zhang Zheng-Tian Xie Jin-rong Wu State Key Laboratory of Polymer Materials Engineering College of Polymer Science and EngineeringSichuan UniversityChengdu610065China Hainan Provincial Key Laboratory of Natural Rubber Processing Agricultural Products Processing Research Institute of Chinese Academy of Tropical Agricultural SciencesZhanjiang524001China

Natural rubber (NR) is widely used in various fields including aerospace, military industry and transportation due to its superior elasticity and comprehensive mechanical properties. Nonetheless, the commercial NR prepared by different methods usually exhibits different mechanical properties, primarily due to variations in processing conditions during the conversion from latex to bulk rubber material. Consequently, this poses challenges in scientific research and industrial production of NR. In order to assess the properties of various commercially available NR and identify key structural and compositional components, this study systematically compares and analyzes four representative NR raw materials: air dried sheet (ADS), ribbed smoked sheets (RSS), constant viscidity NR (CV), and whole field latex rubber (WF). The investigation focuses on evaluating their static mechanical behavior, SIC behavior, wear resistance, and fatigue resistance. The findings indicate that protein and gel content exhibit a crucial influence on the NR properties. These constituents contribute to the formation of a high-crosslinking density region, generating a heterogeneous network structure within the rubber. This structure amplifies strains during deformation, leading to earlier and stronger strain-induced crystallization (SIC). Among the four commercial NR brands, RSS demonstrates superior overall mechanical and dynamic properties owing to its high protein and gel content. This study serves as a valuable reference for comprehending the differences in properties among various commercial NR, thereby offering guidance for the actual processing and selection of NR.

关键词： Natural rubber Processingmethod Protein Gel content Property

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Characterization of the pheromone receptors in Mythimna loreyi reveals the differentiation of sex pheromone recognition in Mythimna species

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Insect Science 2024年第1期31卷 173-185页

作者： Chan Wang Lei Liu Tian-Yu Huang Yu zhang Yang Liu Gui-rong Wang State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina Guangdong Laboratory of Lingnan Modern Agriculture ShenzhenGenome Analysis Laboratory of the Ministry of AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina School of Forestry Northeast Forestry UniversityHarbinChina Key Laboratory of Biohazard Monitoring Green Prevention and Control for Artificial GrasslandMinistry of Agriculture and Rural AffairsInstitute of Grassland Research of Chinese Academy of Agricultural SciencesInner Mongolia HohhotChina

Pheromone receptors(PRs)are key proteins in the molecular mechanism of pheromone recognition,and exploring the functional differentiation of PRs between closely related species helps to understand the evolution of moth mating *** components of the agricultural pest Mythimna loreyi have turned into(Z)-9-tetradecen-1-yl acetate(Z9-14:OAc),(Z)-7-dodecen-1-yl acetate(Z7-12:OAc),and(Z)-11-hexadecen-1-yl acetate,while the composition differs from that of *** in the genus *** understand the molecular mechanism of pheromone recognition,we sequenced and analyzed antennal transcriptomes to identify 62 odorant receptor(OR)*** expression levels of all putative ORs were analyzed using differentially expressed gene *** candidate PRs were quantified and functionally characterized in the Xenopus oocytes ***6 and MlorPR3 were determined to be the receptors of major and minor components Z9-14:OAc and Z7-12:***1 and female antennae(FA)-biased MlorPR5 both possessed the ability to detect pheromones of sympatric species,including(Z,E)-9,12-tetradecadien-1-ol,(Z)-9-tetradecen-1-ol,and(Z)-*** on the comparison of PR functions between *** and ***,we analyzed the differentiation of pheromone recognition mechanisms during the evolution of the mating systems of 2 Mythimna species.

关键词： antennal transcriptome Mythimna loreyi pheromone receptor sex pheromone Xenopus oocyte

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Evaluating the thermal environment of urban land surfaces in Yakutsk,a city located in a region of continuous permafrost

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Advances in Climate Change Research 2024年第1期15卷 113-123页

作者： Xiang-Long LI Ze zhang Jin-Xin LU Anatoli BROUCHKOV Qing-Kai YAN Qi-Hao YU Sheng-rong zhang Andrey MELNIKOV School of Civil Engineering and Transportation Institute of Cold Regions Science and EngineeringPermafrost InstituteNortheast Forestry UniversityHarbin150040China China Railway Qinghai-Tibet Group Company Xining 810000China Department of Geocryology Faculty of GeologyLomonosov Moscow State UniversityMoscow 119234Russian Federation State Key Laboratory of Frozen Soil Engineering Northwest Institute of Eco Envi ronment and Re sourcesChinese Academy of SciencesLanzhou 730000China Melnikov Permafrost Institute Siberian BranchRussian Academy of ScienceYakutsk 677010Russian Federation

Rapid urbanization has led to changes in the urban land surface thermal ***,there are still much unknown about the urban land surface thermal conditions in permafrost *** is a unique geological environment,changes in the urban land surface thermal environment may trigger geological disasters caused by permafrost *** study utilized remote sensing data and geographic de-tectors to identify the dynamic changes in land surface temperature(LST)and land use/land cover(LU/LC)in Yakutsk,as well as the potential factors contributing to LST *** 1992 and 2020,the built-up area in Yakutsk increased by 36%,and the annual average LST in Yakutsk has risen by 6.67℃,accompanied by an expansion of high-temperature *** ongoing greening efforts,rapid urbanization poses a threat to these green *** in the normalized difference built-up index(NDBI)and land use transfer(LDT)were identified as the primary drivers of urban LST *** integrating geographic detector technology and artificial neural network models,we optimized the selection of input factors in the prediction model and used it to explore the future changes in LST in *** average LST in Yakutsk is expected to reach 23.4℃ and 25.1℃ in 2030 and 2040,respectively,with a further increase in high-temperature *** study provides a reference for ecological,hydrological,and geological assessments of cities in permafrost regions.

关键词： Remote sensing Land surface temperature Land use/Land cover Permafrost Yakutsk

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Lightweight Multi-Resolution Network for Human Pose Estimation

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Computer Modeling in Engineering & Sciences 2024年第3期138卷 2239-2255页

作者： Pengxin Li rong Wang Wenjing zhang Yinuo Liu Chenyue Xu School of Information and Cyber Security People Public Security University of ChinaBeijing100038China Key Laboratory of Security Prevention Technology and Risk Assessment of Ministry of Public Security Beijing100038China

Human pose estimation aims to localize the body joints from image or video *** the development of deeplearning,pose estimation has become a hot research topic in the field of computer *** recent years,humanpose estimation has achieved great success in multiple fields such as animation and ***,to obtainaccurate positioning results,existing methods may suffer from large model sizes,a high number of parameters,and increased complexity,leading to high computing *** this paper,we propose a new lightweight featureencoder to construct a high-resolution network that reduces the number of parameters and lowers the *** also introduced a semantic enhancement module that improves global feature extraction and networkperformance by combining channel and spatial ***,we propose a dense connected spatialpyramid pooling module to compensate for the decrease in image resolution and information loss in the ***,ourmethod effectively reduces the number of parameters and complexitywhile ensuring high *** experiments show that our method achieves a competitive performance while dramatically reducing thenumber of parameters,and operational ***,our method can obtain 89.9%AP score on MPIIVAL,while the number of parameters and the complexity of operations were reduced by 41%and 36%,respectively.

关键词： Lightweight human pose estimation keypoint detection high resolution network

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