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Overview of Mechanism and Mitigation Measures on Multi-frequency Oscillation Caused by Large-scale Integration of Wind Power

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CSEE Journal of Power and Energy Systems 2019年第4期5卷 433-443页

作者： Yongning Chi Bingjie Tang Jiabing Hu Xinshou Tian Haiyan Tang Yan Li Sujuan Sun lei Shi lei shuai State Key Laboratory of Operation and Control of Renewable Energy&Storage Systems China Electric Power Research InstituteBeijing 100192China Huazhong University of Science and Technology Wuhan 430074China NARI Group Corporation Nanjing 211000China Siemens Gamesa Renewable Energy A/S Brande 7330Denmark

In recent years,the large-scale integration of re-newable energy sources represented by wind power and the widespread application of power electronic devices in power systems have led to the emergence of multi-frequency oscillation problems covering multiple frequency segments,which seriously threaten system stability and restrict the accommodation of renewable *** oscillation problems related to renewable energy integration have become one of the most popular topics in the field of wind power integration and power system stability *** has received extensive attention from both academia and industries with many promising research results achieved to *** paper first analyzes several typical multi-frequency oscillation events caused by large-scale wind power integration in domestic and foreign projects,then studies the multi-frequency oscillation problems,including wind turbine’s shafting torsional oscillation,sub/super-synchronous oscillation and high frequency *** state of the art is systematically summarized from the aspects of oscillation mechanism,analysis methods and mitigation measures,and the future research directions are explored.

关键词： High-frequency resonance multi-frequency oscillation sub-synchronous oscillation super-synchronous oscillation wind power integration

Carbide Precipitation in Ferrite in Nb–V-Bearing Low-Carbon Steel During Isothermal Quenching Process

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Acta Metallurgica Sinica(English Letters) 2017年第11期30卷 1067-1079页

作者： Xiao-Lin Li Cheng-shuai lei Xiang-Tao Deng Yan-Mei Li Yong Tian Zhao-Dong Wang Guo-Dong Wang State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110819 China

The precipitation behavior of nanometer-sized carbides in ferrite in Nb-V-bearing low-carbon steel was studied by electron microscopy and nanoindentation hardness measurements. The results indicated that interphase precipitation and random precipitation could occur simultaneously for the specimen isothermally treated at 700 ℃ for 60 min, while in other specimens, only random precipitation was observed. This phenomenon might be explained by mass balance criterion during the diffusional phase transformation. Nanohardness result indicated that the average hardness of the specimens isothermally held at 600 ℃ for 20 min was 3.87 GPa. For the specimen isothermally holding at 650 ℃ for 20 min, the average hardness was 4.10 GPa and the distribution of the nanohardness was in a narrower range compared with that of the specimen isothermal holding at 600 ℃ for 20 min. These implied that the carbides in the specimens isothermal treated at 650℃ were more uniformly dispersed, and the number density of the carbides was greater than that treated at 600 ℃. Using Ashby-Orowan model, the contribution of precipitation strengthening to yield strength was estimated to be 110 MPa for the specimen isothermally treated at the temperature of 650 ℃ for 20 min.

关键词： High-strength low-alloy(HSLA) Interphase precipitation Carbides Nanoindentation hardness High-resolution transmission electronic microscopy(HRTEM)

Image reconstruction for the coded aperture system in nuclear safety and security using a Monte Carlo-based system matrix

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Radiation Detection Technology and Methods 2023年第2期7卷 263-270页

作者： Yue Yu Xiaoli Sun Zhiming Zhang Shuangquan Liu Xiuzuo Liang Daowu Li lei shuai Tingting Hu Long Wei Beijing Engineering Research Center of Radiographic Techniques and Equipment Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing100049China Jinan Laboratory of Applied Nuclear Science Jinan250131China

Purpose Accurate localization of radioactive materials is critical to nuclear safety and nuclear security.A coded aperture imaging system provides a visualization ***,the correlation method has poor reconstruction performance for sources with low counts and for extended *** In this study,a Monte Carlo optimization-based MLEM algorithm(MC-MLEM)is *** system matrix was obtained by accurate Monte Carlo simulation,so the physical effects such as mask penetration that affect the imaging process were taken into account in the MLEM *** the simulation process,the normalization of the system matrix was realized by controlling the source at different position of the source plane to have the same activity and emission *** The experimental results showed that compared with the correlation method,the MC-MLEM algorithm could improve the signal-to-noise ratio and angular resolution and locate the source position quickly and accurately under low count ***,the MC-MLEM algorithm could reconstruct the shape of the extended source and the expected activity ratio of cold-hot sources with large activity *** The MC-MLEM algorithm improved the imaging results and enhanced the reconstruction performance.

关键词： Coded aperture System matrix Image reconstruction Low count imaging Extended sources

Generation of recombinant rabies virus ERA strain applied to virus tracking in cell infection

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Journal of Integrative Agriculture 2019年第10期18卷 2361-2368页

作者： ZHAO Dan-dan shuai lei GE Jin-ying WANG Jin-liang WEN Zhi-yuan LIU Ren-qiang WANG Chong WANG Xi-jun BU Zhi-gao State Key Laboratory of Veterinary Biotechnology Harbin Veterinary Research InstituteChinese Academy of Agricultural SciencesHarbin 150069P.R.China Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses Yangzhou UniversityYangzhou 225009P.R.China

The mechanism of rabies virus (RABV) infection still needs to be further characterized. RABV particle with self-fluorescent is a powerful viral model to visualize the viral infection process in cells. Herein, based on a reverse genetic system of the Evelyn-Rokitnicki-Abelseth (rERA) strain, we generated a recombinant RABV rERA-N/mCherry strain that stably expresses an additional ERA nucleoprotein that fuses with the red fluorescent protein mCherry (N/mCherry). The rERA-N/mCherry strain retained growth property similar to the parent strain rERA in vitro. The N/mCherry expression showed genetic stability during passage into mouse neuroblastoma (NA) cells and did not change the virulence of the vector. The rERA-N/mCherry strain was then utilized as a visual viral model to study the RABV-cell binding and internalization. We directly observed the red self-fluorescence of rERA-N/mCherry particles binding to the cell surface, and further co-localizing with clathrin in the early stage of infection in NA cells by fluorescence microscopy. Our results showed that the rERA-N/mCherry strain uses clathrin-dependent endocytosis to enter cells, which is consistent with the well-known mechanism of RABV invasion. The recombinant RABV rERA-N/mCherry thus appears to have the potential to be an effective viral model to further explore the fundamental molecular mechanism of rabies neuropathogenesis.

关键词： rabies virus self-fluorescence binding internalization

YSO coded aperture camera based on depth of interaction for location correction

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Radiation Detection Technology and Methods 2023年第4期7卷 589-598页

作者： Yiding Han Xiaopan Jiang Haohui Tang Xiuzuo Liang Xuanhou Hu Xianchao Huang Zhiming Zhang lei shuai Jing Guo Long Wei Beijing Engineering Research Center of Radiographic Techniques and Equipment Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing100049China Jinan Laboratory of Applied Nuclear Science Jinan250131China CAEA Center of Excellence on Nuclear Technology Applications for Nuclear Detection and Imaging TaiyuanChina

Purpose Coded aperture imaging was a widely used imaging method for radiation ***,the traditional gamma camera based on two-dimensional projection information for coded aperture imaging ignored the influence of the interaction depth of particles and detectors on the projection information,which reduced the imaging quality of the camera to some ***,a method of correcting the coded gamma camera based on the interaction depth of particles and detectors is proposed to improve the location accuracy of *** The camera developed in this work uses a 7×7 YSO crystal array coupled with two 7×7 Si-PM *** crystal is evenly divided into 11 parts in the depth direction,with a voxel size of 3×3×3 *** coded mask is a 13×13 array,which is a mosaic of two cycles of 7×7 modified uniformly redundant array *** depth resolution of the detector is obtained via the subsurface laser engraving dual-end readout *** obtaining the three-dimensional position information of the interaction point the projection information obtained by the detector is layered,and the image is *** to the spatial position information of the detector and the coded mask,the corresponding field of view of each layer of the detector is calculated,and the reconstructed image of each layer is amplified and superimposed according to the ratio of the field of view to obtain the reconstructed image combined with the depth *** and conclusion According to Monte Carlo simulation and radiation source imaging experiment results,this method can effectively improve the positioning ability of the *** the experimental scenario mentioned in the paper,the location accuracy can be improved by up to 1.54°.

关键词： Depth of interaction Coded aperture gamma camera YSO detector Location accuracy

CLSTM-KF reconstruction method for a low-activity moving radiation source localization and tracking with a coded-aperture gamma camera

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Radiation Detection Technology and Methods 2021年第2期5卷 228-237页

作者： Yi Zou Shuang‑Quan Liu Xiao‑Li Sun Yue Yu Mo‑Han Li Chun‑Miao Li lei shuai Long Wei Beijing Engineering Research Center of Radiographic Techniques and Equipment Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Jinan Laboratory of Applied Nuclear Science Jinan 250131China

Background Accurate localization of a low-activity moving radiation source plays an important role in nuclear security and *** coded-aperture gamma camera is generally applied to detect a radiation source,but its reconstruction methods may have some limitations when the radiation source is motional and *** The purpose of this paper is to improve the quality of the reconstruction images and the localization accuracy when detecting a low-activity moving radiation source with a gamma *** The CLSTM-KF method consists of the CLSTM network and the Kalman *** CLSTM network is applied to improve the CNR of reconstruction images by making an adaptive superposition for sequential reconstruction images decoded by the correlation analysis *** the CLSTM network,a series of sequential positions would be filtered by the Kalman *** By comparing with the traditional methods of the gamma camera,the CLSTM-KF method performs well in improving both the CNR of reconstruction images and the localization ***,the computation time of the CLSTM-KF method can also meet the application *** In summary,the CLSTM-KF method provides a better choice than the traditional methods in locating and tracking a low-activity moving radiation source.

关键词： Low activity Coded-aperture gamma camera Convolutional long short

Molecular epidemiological study of animal rabies in Kazakhstan

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Journal of Integrative Agriculture 2023年第4期22卷 1266-1275页

作者： Gulzhan N.YESSEMBEKOVA XIAO Shuang Assem ABENOV Talgat KARIBAEV Alexandr SHEVTSOV Amirgazin ASYLULAN Yersyn Y.MUKHANBETKALIYEV shuai lei BU Zhi-gao Sarsenbay K.ABDRAKHMANOV S.Seifullin Kazakh Agro Technical University Nur-Sultan 010011Kazakhstan State Key Laboratory for Animal Disease Control and Prevention Harbin Veterinary Research InstituteChinese Academy of Agricultural SciencesHarbin 150069P.R.China National Reference Center for Veterinary Medicine Center for BiotechnologyNur-Sultan 010000Kazakhstan National Center for Biotechnology Nur-Sultan 010000Kazakhstan

Rabies is a serious public health issue in Kazakhstan, with high economic impact and social burden. As part of a routine surveillance, 31 rabies-positive brain specimens taken from livestock(cattle) and carnivores(dogs, foxes, and cats)during 2013–2021 were subject to viral sequencing. Phylogenetic and Bayesian analysis were performed using obtained rabies virus(RABV) sequences. All 31 strains of RABV candidate belonged to the Cosmopolitan clade, of which 30strains belonged to steppe-type subclade, and 1 dog strain belonged to Other subclade. The 31 strains did not diverge from RABV strains in Kazakhstan and neighboring countries, including Russia, Mongolia, and China, suggesting that animal rabies has close relationship and transmission between borders. Fox-originated strains and cattle strains shared similar sequence signature, and some animal rabies cases had space–time intersection, showing that infected foxes were a major transmission source of cattle rabies in different Kazakhstan regions. Besides, free-roaming dogs played a pivotal role in rabies epizootics of cattle in Kazakhstan. The recent spread of animal rabies presents an increasing threat to public health, and provides updated information for improving current control and prevention strategies at the source for Kazakhstan and neighboring countries.

关键词： rabies livestock carnivores phylogenetic analysis

有向切换拓扑条件下多航天器分组姿态协同控制

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控制与决策 2021年第10期36卷 2389-2398页

作者：周绍磊王帅磊刘伟海军航空大学研究生管理大队山东烟台264001

针对有向切换拓扑条件下多航天器分组姿态协同控制问题,提出一种基于变量代换和矩阵分解的控制方法.首先,给出分组情况下系统Laplacian矩阵特征值的性质,并对航天器姿态模型进行变量代换,将非线性系统的分组姿态协同问题转化为线性系统... 详细信息

针对有向切换拓扑条件下多航天器分组姿态协同控制问题,提出一种基于变量代换和矩阵分解的控制方法.首先,给出分组情况下系统Laplacian矩阵特征值的性质,并对航天器姿态模型进行变量代换,将非线性系统的分组姿态协同问题转化为线性系统的分组一致问题;然后,通过分解Laplacian矩阵,将分组一致问题转化为线性切换系统的稳定性问题,从而通过Lyapunov稳定性理论进行分析,给出系统拓扑的最小驻留时间;最后,对包含两个分组的系统进行仿真,结果表明了所提出控制方法的有效性.

关键词：航天器姿态协同控制分组切换拓扑矩阵分解驻留时间

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生物考古学视野下人类的牙齿与饮食

人类学学报 2022年第3期41卷 501-513页

作者：雷帅郭怡浙江大学艺术与考古学院杭州310028

饮食在人类文化的起源与演变中扮演着重要角色,而牙齿作为饮食信息的主要载体,从不同角度为复原古代人类饮食谱系提供了可能。作为人类咀嚼行为、饮食结构及生业模式的直接反映,口腔疾病和牙齿表面微观痕迹的体质人类学分析显得尤其重... 详细信息

饮食在人类文化的起源与演变中扮演着重要角色,而牙齿作为饮食信息的主要载体,从不同角度为复原古代人类饮食谱系提供了可能。作为人类咀嚼行为、饮食结构及生业模式的直接反映,口腔疾病和牙齿表面微观痕迹的体质人类学分析显得尤其重要。牙齿中微量元素和稳定同位素的检测,对于揭示古代人类的迁徙与流动、生命在不同阶段的摄食行为与营养状况、农业的起源与发展等问题具有着不可估量的作用。本文在回顾考古遗址中出土人类牙齿的重要性及研究方法的多样性基础上,结合牙齿的生长发育特征,绘制了不同牙位各生长序列所匹配的人类年龄图谱,并参照此图谱,提出了全新的牙本质连续切片取样方法。本文构想从体质人类学与碳、氮等稳定同位素分析的角度出发,以牙本质的连续切片、肢骨及肋骨等人体组织为关联式地研究材料,在探索古人类个体生命史的基础上展望“代际考古”。

关键词：牙齿稳定同位素分析食谱重建 “代际考古”