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Electrically Switchable Longitudinal Nonlinear Conductivity in Magnetic Semiconductors

Physical Review Letters 2025年第4期134卷 046801-046801页

作者： Hong Jian Zhao Yuhao Fu Yurong Yang Yanchao Wang Laurent Bellaiche Yanming Ma Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University Changchun 130012 China Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education) College of Physics Jilin University Changchun 130012 China International Center of Future Science Jilin University Changchun 130012 China National Laboratory of Solid State Microstructures and Jiangsu Key Laboratory of Artificial Functional Materials Department of Materials Science and Engineering Nanjing University Nanjing 210093 China State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun 130012 China Smart Functional Materials Center Physics Department and Institute for Nanoscience and Engineering University of Arkansas Fayetteville Arkansas 72701 USA Department of Materials Science and Engineering Tel Aviv University Ramat Aviv Tel Aviv 6997801 Israel

Writing data by electric field (as opposed to electric current) offers promises for energy efficient memory devices. While this data writing scheme is enabled by the magnetoelectric effect, the narrow spectrum of room-temperature magnetoelectrics hinders the design of practical magnetoelectric memories, and the exploration of other mechanisms toward low-power memories is greatly demanding. Here, we propose a mechanism that allows the electric-field writing of data beyond the framework of magnetoelectric effect. By symmetry analysis, we show that electric field can induce longitudinal nonlinear conductivity (LNC) in a wide spectrum of magnetic materials, including ferromagnets, antiferromagnets, magnetoelectrics, and nonmagnetoelectrics. The LNC is electrically switchable by reversing the electric field, where the switched LNC is detectable by transport measurements. Our first-principles simulations combined with transport calculations further predict YFeO3 and CuFeS2 (room-temperature antiferromagnets) to showcase electrically switchable LNC. Our Letter helps enrich the research avenues in nonlinear charge transport, and offers a pathway for designing energy efficient devices based on LNC.

关键词： Magnetoelectric effects

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Soil microbial communities regulate the threshold effect of salinity stress on SOM decomposition in coastal salt marshes

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Fundamental Research 2023年第6期3卷 868-879页

作者： Guangliang Zhang Junhong Bai Jia Jia Wei Wang Dawei Wang Qingqing Zhao Chen Wang Guozhu Chen State Key Laboratory of Water Environment Simulation School of EnvironmentBeijing Normal UniversityBeijing 100875China Advanced Institute of Natural Sciences Beijing Normal UniversityZhuhai 519087China Henan Key Laboratory of Ecological Environment Protection and Restoration of Yellow River Basin Yellow River Institute of Hydraulic ResearchZhengzhou 450003China Shandong Provincial Key Laboratory of Applied Microbiology Ecology InstituteQilu University of Technology(Shandong Academy of Sciences)Ji'nan 250103China

Salinity stress is one of the critical environmental drivers of soil organic matter(SOM)decomposition in coastal *** the temperature sensitivity(Q_(10))of SOM decomposition has been widely applied in Earth system models to forecast carbon processes,the impact of salinity on SOM decomposition by restructuring microbial communities remains ***,we conducted a microcosm experiment with soils collected from the coastal salt marsh in the Yellow River Estuary,which is subjected to strong dynamics of salinity due to both tidal flooding and *** setting a gradient of salt solutions,soil salinity was adjusted to simulate salinity stress and soil carbon emission(CO_(2))rate was measured over the *** showed that as salinity increased,the estimated decomposition constants based on first-order kinetics gradually decreased at different *** the 20‰salinity treatments,which doubled the soil salinity,Q_(10)increased with increasing salinity;but higher salinity constrained the temperature-related response of SOM decomposition by inhibiting microbial growth and carbon *** bacteria were more sensitive to salinity stress than fungi,which can be inferred from the response of microbial beta-diversity to changing *** them,the phylotypes assigned to Gammaproteobacteria and Bacilli showed higher salt tolerance,whereas taxa affiliated with Alphaproteobacteria and Bacteroidota were more easily inhibited by the salinity *** fungal taxa belonging to Ascomycota had higher adaptability to the *** the substrate was consumed with the incubation,bacterial competition intensified,but the fungal co-occurrence pattern changed weakly during ***,these findings revealed the threshold effect of salinity on SOM decomposition in coastal salt marshes and emphasized that salt stress plays a key role in carbon sequestration by regulating microbial keystone taxa,metabolisms,and interactions.

关键词： Salt marshes Salinity stress Soil organic matter decomposition Temperature sensitivity Threshold effect Microbial community

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Effect of Heat and Cryogenic Treatments on the Microstructure and Properties of Yf3 Modified Niti-Si Laser Cladding Coatings

SSRN

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SSRN 2022年

作者： Su, Wennan Zhang, Chi Cui, Xiufang Jin, Guo Liu, Changhao Liu, Erbao Li, Jian Zhao, Haonan Cao, Boyu Tian, Haoliang Institute of Surface/Interface Science and Technology Key Laboratory of Superlight Material and Surface Technology Ministry of Education College of Material Science and Chemical Engineering Harbin Engineering University Harbin150001 China Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Material Beijing Beijing Institute of Aeronautical Materials Beijing100095 China

YF 3 modification NiTi-Si coatings were prepared on Ti6Al4V substrate by laser cladding. On this foundation, heat and cryogenic treatments were conducted respectively to explore the effect of after-treatment procedures. The consequence of post-treatment methods on the phase constituent, microstructure, mechanical property, and phase transition characteristics of post-treatment coatings was studied. The phase constituent of the three coatings is roughly the same, composed of NiTi and NiTi 2 . Simultaneously, eutectic structures were found in three coatings, which also proved that the post-treatment would not affect the appearance of the eutectic structure. The results show that heat treatment led to the coarsening of the grain size of the NiTi phase, and the composition of Si element in the NiTi 2 phase increased. On the contrary, the cryogenic treatment led to the refinement of grains and eutectic structure in the coatings. In addition, due to the rapid cooling rate provided by cryogenic treatment, the spinodal decomposition of the Si element occurred in the NiTi 2 phase, which was confirmed by TEM and EDS. The microhardness of the three coatings is as follows: cryogenic treatment>original coatings>heat treatment. The cryogenic treatment coating has the highest microhardness due to grain refinement and spinodal decomposition. Furthermore, the post-treatments also affected the phase transformation characteristics of the coatings. © 2022, The Authors. All rights reserved.

关键词： Coatings

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Frequency Modulation Strategy of Wind Power Generation in Power System of High Renewable Penetration

Frequency Modulation Strategy of Wind Power Generation in Po...

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Power Energy Systems and Applications (ICoPESA), International Conference on

作者： Chengbin Chi Shan Liu Qi Liu Fan Li State Key Laboratory of Advanced Power Transmission Technology State Grid Smart Grid Research Institute Co. Ltd Beijing China Beijing Key Laboratory of DC Grid Technology and Simulation State Grid Smart Grid Research Institute Co. Ltd Beijing China State Grid Shanghai Municipal Electric Power Compan Shanghai China

Wind turbines generally adopt the maximum wind energy tracking control strategy, which makes them obtain the best power generation efficiency. However, this makes wind turbines unable to respond to changes in system conditions, provide inertial support for the system, and participate in the primary frequency modulation of the system, which brings challenges to the frequency safety of high-proportion new energy power systems. In order to improve the frequency stability of high-proportion new energy power system and make wind turbines participate in frequency control actively, this paper proposes a primary frequency modulation control strategy based on load reduction for doubly-fed wind turbines. According to the aerodynamic characteristics of variable pitch wind turbine, a coordinated load shedding control strategy combining variable pitch and variable speed operation was proposed to make the wind turbine have active power reserve capacity. A frequency response link is added to the power control, so that the unit can output power to realize inertia and frequency support when the system frequency fluctuates. The simulation results show that the proposed control strategy can improve the system inertia and primary frequency modulation capability in the full wind speed operating domain under the load mutation condition, and improve the frequency stability of the system after the wind turbine is connected to the grid.

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Enhanced Power Synchronization Based Vector Control with Fault Ride Through for VSC-HVDC

Enhanced Power Synchronization Based Vector Control with Fau...

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IEEE International Conference on Power and Power and Renewable Energy (ICPRE)

作者： Rongcai Pan Chunpeng Li Yuexi Yang Xiao Zhou State Key Laboratory of Advanced Power Transmission Technology State Grid Smart Grid Research Institute Co. Ltd Beijing P. R. China Beijing Key Laboratory of DC Grid Technology & Simulation State Grid Smart Grid Research Institute Co. Ltd Beijing P. R. China

The power synchronization based vector control is proposed with the power synchronization controller (PSC) replacing the conventional phase locked loop (PLL) recently. It is reported that the power synchronization unit can have comparable performance of the conventional PLL based vector control. However, the steady state analysis of the PSC control dq frame orientation and the corresponding steady equilibrium points are not discussed. Worse more, fault ride through of the PSC based vector control is not addressed in the related literatures. First, the measurements error on the performance on PSC based vector control is analyzed and the enhanced PSC based vector control is proposed to further reduce the control complexity. Based on the enhanced PSC based vector control, the equilibrium points and the dq frame orientation of PSC based vector control and its comparison with PLL based one are analyzed in the normal operation. After that, the fault ride through strategy is proposed with consideration of equilibrium point. Finally, simulations using PSC based vector control for voltage source converter based high voltage dc transmission station (VSC-HVDC) are carried out to verify the analysis.

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Erratum to:Finite element simulation and experimental test of the wear behavior for self-lubricating spherical plain bearings

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Friction 2024年第7期12卷 1620-1620页

作者： Yahong XUE Jigang CHEN Sumin GUO Qingliang MENG Junting LUO School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Aviation Key Laboratory of Science and Technology on Generic Technology of Self-Lubricating Spherical Plain Bearing Yanshan UniversityQinhuangdao 066004China Education Ministry Key Laboratory of Advanced Forging and Stamping Technology and Science Yanshan UniversityQinhuangdao 066004China

Erratum to Friction 10(6):803–841(2022)Yahong Xue,Jigang Chen,Sumin Guo,Qingliang Meng&Junting *** element simulation and experimental test of the wear behavior for self-lubricating spherical plain *** 6(3):297–306(2018).https://***/10.1007/s40544-018-0206-x The authors regret that there was an inadvertent error in Fig.10(c)after checking the *** is important to note that the change does not impact the main conclusion of the *** 10(c)on page 304 was selected as the incorrect picture,and the accurate version of Fig.10(c)is provided as below.

关键词： wear Friction bearings

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Analysis and Improvement of the AC-Voltage Control of GFM MMC to Improve the Voltage Stability of AC/DC Hybrid Power Grid

Analysis and Improvement of the AC-Voltage Control of GFM MM...

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IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG)

The grid-forming control is regarded as an effective solution for grid-tied converters to operate under weak grid conditions. Currently, most of the grid-forming control strategies are designed for 2-level voltage source converters. The Power loop-AC voltage loop-AC current loop control is usually adopted in these strategies. This control structure highly relies on the AC side filter capacitor. However, in high-voltage situations, the modular multilevel converter, which has no AC side filter capacitor, is commonly adopted. The integral effect of the filter capacitor in the original control path is replaced by the differential effect of the grid impedance, which worsens the performance of AC voltage control. To solve this problem, the steady-state model of MMC using grid-forming control is established. Based on this model, two improved AC-voltage control strategies are proposed in this paper. simulation results in PSCAD/EMTDC show that the proposed control realizes desired dynamic control of the DC voltage.

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Auto-focused Sparse Bayesian Learning for ISAR Imagery Based on Spike-and-Slab Prior Via Variational Approximation 10

Auto-focused Sparse Bayesian Learning for ISAR Imagery Based...

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10th International Conference on Control, Automation and Information Sciences, ICCAIS 2021

作者： Sun, Weitian Yang, Lei Dou, Yuchen Li, Xuan Fang, Cheng Civil Aviation University of China Tianjin Key Laboratory for Advanced Signal Processing Tianjin China Macalester College Saint Paul United States China Greatwall Technology Group Co. Ltd Shenzhen China

ISBN: (纸本)9781665440295

For inverse synthetic aperture radar (ISAR) imagery, the scatterers of target of interest are inherently sparse in spatial domain. In order to encode the sparsity, the sparse Bayesain model is a popular choice as a statistical manner, where Laplace distribution is imposed on the signal. Meanwhile, the sparse Bayesian model provides a confidential knowledge in the result. Due to the inaccurate compensation of the translational motion of interested target, the phase error correction is incorporated in the sparse Bayesian model to achieve high-resolution for ISAR imaging. In this papar, a novel antofocus sparse Bayesian Learning based on the spike-and-slab prior (SSP-AFSBL) is proposed, which can induce and enhance the sparse feature more flexibly. Due to the nonconjugacy of the likelihood and prior, a hierarchical Bayesian model is performed to provide the full Bayseian inference for the sparse coefficients. To avoid the calculation of a multidimensional integral, the variational Bayesian (VB) approximation is adopted to derive the analytical solution to hyperparameters. Finally, qualitative and quantitative analysis based on simulated and raw datasets have demonstrated the effectiveness of the proposed algorithm. © 2021 IEEE.

关键词： Inverse synthetic aperture radar

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核子电磁形状因子振荡行为的新视角

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Science Bulletin 2023年第22期68卷 2729-2733,M0005页

作者：杨勤鹤郭棣戴凌云 Johann Haidenbauer 康现伟 Ulf-GMeiner School of Physics and Electronics Hunan UniversityChangsha 410082China Hunan Provincial Key Laboratory of High-Energy Scale Physics and Applications Hunan UniversityChangsha 410082China Institute for Advanced Simulation Institut für Kernphysik and Jülich Center for Hadron PhysicsForschungszentrum JülichJülich D-52425Germany Key Laboratory of Beam Technology of the Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China Helmholtz Institut für Strahlen-und Kernphysik and Bethe Center for Theoretical Physics Universität BonnBonn D-53115Germany Tbilisi State University Tbilisi 0186Georgia

本文研究了质子和中子的类时电磁形状因子.作者基于手征有效场论,通过求解李普曼-施温格方程得到了核子-反核子对散射振幅.以此为输入,利用扭曲波恩近似方法描述了核子末态相互作用,计算了正负电子湮灭到正反核子对的过程.通过拟合相移... 详细信息

本文研究了质子和中子的类时电磁形状因子.作者基于手征有效场论,通过求解李普曼-施温格方程得到了核子-反核子对散射振幅.以此为输入,利用扭曲波恩近似方法描述了核子末态相互作用,计算了正负电子湮灭到正反核子对的过程.通过拟合相移、截面以及微分截面等实验数据,定下了有效场论的未知耦合常数.进一步研究发现,可以利用两个分数振荡振子来描述核子电磁类时形状因子的振荡行为:一个表现为过阻尼振荡,在阈值附近占主导地位;另一个类似于欠阻尼振荡,在高能区起到重要作用.这种振荡行为对理解硬光子诱导的核子内部极化电荷的分布起着至关重要的作用.

关键词： Electromagnetic form factors Fractional oscillator Chiral effective field theory Lippmann-Schwinger equation Distorted wave Born approximation

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AMAS: A DNN-Based Automatic Manhours Approval System

AMAS: A DNN-Based Automatic Manhours Approval System

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Mechanical, Automation and Electrical Engineering (CMAEE), International Conference on

作者： Yunfei Jia Hao Lu Debin Hu Tianjin Key Laboratory for Advanced Signal Processing Civil Aviation University of China Tianjin China Suzhou Weizhong Data Technology Co. Ltd Suzhou China

Manhours estimation and automatic approval plays an important role in project scheduling and reducing the development cost for factory. Traditional approaches usually have some limitations, such as technical text formatting limitations and industry-specific limitations. This paper presents a software system that estimates the manhours and approves the technology texts that have been submitted. Firstly, we collect a technology texts dataset and complement the dictionaries. Secondly, the word2vec is used to extract the features implicated in the technology text, and a DNN (deep neural network) model is proposed to estimate the manhours. Finally, an Odoo-based software system is developed, which provides the estimation manhours and approves automatically of the submitted technology texts. The advantages of approach in which is proposed in this paper is that, it has less limitations on the format of submitted technology texts. And, it can be used for various production technology.

关键词： Training Industries Electrical engineering Job shop scheduling Software algorithms Neural networks Estimation

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