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Protection and Control of Modern Power Systems 2022年第1期7卷 316-323页

作者： haibo xu Yupeng Cai Xiaolei Qu Zhiwei Dong NARI Group Corporation/State Grid Electric Power Research Institute Nanjing 210003China Electric Power Research Institute of State Grid Liaoning Electric Power Co. LtdShenyang 110006China

Out-of-step oscillation separation devices based on apparent impedance angle trajectory are widely used in the power grid in China,and their reliability is of great importance.In this paper,the influence mechanism of series compensation on apparent impedance angle trajectory is analyzed.It reveals that series compensation capacitors reduce the equivalent impedance angle and consequently the apparent impedance angle cannot pass through all four zones,resulting in the risk of failure for the separation devices.A revised method of apparent impedance angle based on compensation principle is discussed,and then an improved out-of-step oscillation detection criterion is proposed.In view of the fact that the apparent impedance angle at the moment of maximum current is equal to the equivalent impedance angle during an oscillation process,a practical algorithm based on the compensated apparent impedance angle is proposed.RTDS tests are conducted to verify the effectiveness of the new criterion,considering transmission lines with a high series compensation level.

关键词： Out-of-step oscillation separation Series compensated line Apparent impedance angle Compensated impedance angle

Dry passivation of austenitic SUS 301L stainless steel against pitting corrosion in marine atmospheric environment

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Journal of Oceanology and Limnology 2022年第4期40卷 1437-1447页

作者： Yonghong LU Xiao LIU Lisha WANG Jinghong YANG haibo xu Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China 2 CRRC Changchun Railway Vehicles Co.Ltd.Changchun 130062China

Being an exclusive construction material for lightweight rail vehicles,protection from pitting corrosion in harsh marine atmospheric environment in high humidity and Cl-ion concentration is critical for austenitic SUS 301L stainless steel(SS),especially when it inevitably suff ers from mechanical damages during post disposals.Herein,an innovative dry passivation method for austenitic SUS 301L SS was established in a closed air atmosphere at low temperature and constant pressure.The process parameters were optimized,and the passivation mechanism was explained using polarization curve,electrochemical impedance spectroscopy(EIS),X-ray photoelectron spectroscopy(XPS),and contact angle measurement.The pitting corrosion susceptibility of the passive fi lm prepared in a closed air chamber under 1.0×10^(5) Pa at 80℃ for 80 min was evaluated in 3.5%NaCl solution and exhibited higher pitting potential and corrosion resistance,lower passivity-maintaining current density,and wettability when compared with conventional nitric acid treatment.Besides,dry passivation facilitated the repairing of the surface structural defect itself and the post-processing damage,similar to the accelerated aging of fi lm.The decrease in oxygen concentration and convection-diff usion strengthened the preferential chromium oxidation to form a compact chromium-rich passive fi lm to resist the aggression of Cl-ion.

关键词： austenitic stainless steel passive film dry passivation pitting corrosion chloride ion

Calcium hydride reduced high-quality Nd-Fe-B powder from Nd-Fe-B sintered magnet sludge

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Journal of Rare Earths 2022年第12期40卷 1905-1912,I0004页

作者： haibo xu Qingmei Lu Liying Cong Haowen Tian Weiqiang Liu Youhao Liu Yunqiao Wang Jingwu chen Xiaofei Yi Ming Yue Key Lab of Advanced Functional Materials Ministry of EducationFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China State Key Laboratory of Rare Earth Permanent Magnetic Materials Hefei 231500China Earth–Panda Advanced Magnetic Materials Co. Ltd.Hefei 231500China Beijing Zhong Ke San Huan Research Beijing 102200China

The structural and magnetic properties were studied for recycling Nd-Fe-B powders from Nd-Fe-B sintered magnets sludge via reduction diffusion(RD)with calcium hydride(CaH_(2))particles.For comparison,traditional reducing agent calcium granules were applied to prepare recycled Nd-Fe-B powders.Finer particle size and better size distribution as well as lower impurity content are achieved by using CaH_(2)instead of Ca.In detail,the average particle size of the recycled Nd-Fe-B powder is reduced from 4.66 to 3.43μm,and the bimodal distribution disappears.Moreover,the residual calcium content and oxygen content are reduced to about 0.080 wt%and 0.32 wt%.As a consequence,the roomtemperature magnetization of the CaH_(2)-recycled Nd-Fe-B powder is increased to 146.30 emu/g,6.8%and 33%,respectively,higher than that of Ca-reduced powder and the initial sludge.Further analysis indicates that CaH_(2)is able to reduce the sludge at lower tempe rature to fabricate well-dispersed,unifo rm recycled powder with high magnetization arising from a combination factors of its low melting point,low thermodynamic behavior,and the release of hydrogen during the reaction.

关键词： Recycled Nd-Fe-B powders Magnetic properties Microstructure Reducing agent Reduction diffusion Rare earths

Elevated Pulse Pressure Is a Risk Factor for Cerebral Microbleeds. A Single Center Case-Control Study

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International Journal of Clinical Medicine 2023年第2期14卷 116-128页

作者： Christopher Ntege haibo xu Department of Radiology Zhongnan Hospital of Wuhan University Wuhan China

Recent developments in brain magnetic resonance imaging using advanced Susceptibility Weighted Imaging (SWI) have significantly increased the detection and prevalence of Cerebral Microbleeds (CMBs). Here, we aimed to explore the association between Pulse Pressure (PP) and CMBs. Having been implicated in various arteriopathies, we hypothesized that elevated PP could also be a risk for CMBs. A retrospective case-control study was conducted from August 2021 to September 2022 at Zhongnan Hospital of Wuhan University China. Extracted data were analyzed in SPSS. Chi-square test, binary logistic regression, and Spearman’s correlation analysis were conducted.104 patients were analyzed. Univariate analysis showed no significant association between PP and CMBs, OR 1.65 (95% CI: 0.737 - 3.694;p > 0.05), while DBP and alcohol consumption were significant, ORs 2.956 (95% CI: 1.249 - 6.997, p < 0.05) and 2.525 (95% CI: 1.062 - 6.002, p < 0.05) respectively. Multivariate analysis, showed that PP was significantly associated with CMBs, OR 3.194 (95% CI: 1.024 - 9.964, p < 0.05) in combination with SBP, DBP, gender, age, smoking and alcohol consumption. Taken together, the study showed that elevated PP is associated with CMB, but is not an independent risk factor for CMBs.

关键词： Cerebral Microbleeds Pulse Pressure Susceptibility Weighted Imaging MRI CMBs

A facile process to optimize performance of regenerated Nd-Fe-B sintered magnets:Chemo-selective dissolution washing

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Journal of Rare Earths 2023年第12期41卷 1976-1983,I0006页

作者： haibo xu Qingmei Lu Lichao Yu Liying Cong Haowen Tian Weiqiang Liu Youhao Liu Yunqiao Wang Jingwu Chen Xiaofei Yi Qiong Wu Ming Yue College of Materials Science&Engineering Key Lab of Advanced Functional MaterialsBeijing University of TechnologyBeijing100124China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou341119China State Key Laboratory of Rare Earth Permanent Magnetic Materials Hefei231500China Earth-Panda Advanced Magnetic Materials Co. Ltd.Hefei231500China Beijing Zhong Ke San Huan Research Beijing102200China

In this work,the recycled Nd-Fe-B powders and regenerated Nd-Fe-B sintered magnets with low impurity content were successfully prepared from Nd-Fe-B magnet sludge via reduction diffusion(RD)method followed by a chemo-selective dissolution washing proc ess.The chemo-selective dissolution effect of various solution(deionized water,dilute acetic acid solution,NH_(4)Cl-methanol solution) was evaluated by impurity content and magnetic properties of the recycled Nd-Fe-B powder.The NH_(4)Cl-methanol solution can selectively remove impurities with minimal damage to the magnetic phase.Besides,the optimal NH_(4)Cl concentration and liquid-to-solid ratio were investigated.As a consequence,the contents of Ca,O,and H after optimal washing process are reduced to 0.07 wt%,0.31 wt% and 0.22 wt%,respectively.Hence,M_(3) Tis increased to 146.72 emu/g,which is 33% higher than that of the initial sludge.Then,the regenerated Nd-Fe-B sintered magnets with properties of B_(r)=11.66 kG,H_(cj)=16.49 kOe,and(BH)_(m)=31.78 MGOe were successfully prepared by mixing with 40 wt% Nd4Fe14B alloy powders.Compared with the corresponding regenerated magnets washed with deionized water,the remanence and coercivity are increased by 18% and 59%,respectively.

关键词： Recycling Nd-Fe-B magnet Sludge Chemo-selective dissolution Washing process Magnetic properties Reduction diffusion Rare earths

基于数字孪生的安全稳定控制系统试验验证展望

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电力系统自动化 2024年第5期48卷 1-10页

作者：许剑冰冯霄峰徐海波李满礼南瑞集团有限公司(国网电力科学研究院有限公司) 江苏省南京市211106 国电南瑞科技股份有限公司江苏省南京市211106

随着新型电力系统建设的推进,安全稳定控制系统呈现出控制对象增多、控制范围增大、耦合性增强、复杂度增高的趋势,现有工程试验验证方法无法满足未来安全稳定控制系统试验验证需求。考虑到数字孪生技术具有高保真、实时性、交互性的特... 详细信息

随着新型电力系统建设的推进,安全稳定控制系统呈现出控制对象增多、控制范围增大、耦合性增强、复杂度增高的趋势,现有工程试验验证方法无法满足未来安全稳定控制系统试验验证需求。考虑到数字孪生技术具有高保真、实时性、交互性的特点,结合数字孪生技术的内涵、模型、架构,提出了基于数字孪生的安全稳定控制系统试验验证架构。最后,对所涉及的关键技术进行了展望。

关键词：安全稳定控制系统试验验证建模数字孪生

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点探测器敏感性关联抽样计算方法

原子能科学技术 2024年第3期58卷 638-644页

作者：李瑞付元光邓力许海波中物院高性能数值模拟软件中心北京100088 北京应用物理与计算数学研究所北京100094

为避免点探测器敏感性计算中随机统计涨落的影响,研究了在蒙特卡罗关联抽样算法框架下,点探测器敏感性的计算方法。在算法中考虑了输运过程偏倚以及存在次级粒子的情况,给出了输运扰动权乘子与计数扰动权乘子的更新方案。针对点探测器... 详细信息

为避免点探测器敏感性计算中随机统计涨落的影响,研究了在蒙特卡罗关联抽样算法框架下,点探测器敏感性的计算方法。在算法中考虑了输运过程偏倚以及存在次级粒子的情况,给出了输运扰动权乘子与计数扰动权乘子的更新方案。针对点探测器敏感性中次级粒子的模拟特点,引入了单因素扰动系统,并基于粒子扩展属性实现了对单因素扰动系统微扰的模拟,从而避免了对次级粒子历史进行回溯。利用脉冲球形实验装置,测试了散射截面扰动下点探测器的敏感性计算功能,并与微分算符方法的计算结果进行了比较,以验证其计算精度。利用NUREG/CR-6115屏蔽基准题测试了权重技巧下算法的适用性。测试表明,算法与微分算符方法计算精度相当,并适用于屏蔽问题点探测器敏感性模拟。

关键词：点探测器敏感性关联抽样蒙特卡罗

A multi-material diagnosis method based on high-energy proton radiography

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Matter and Radiation at Extremes 2023年第4期8卷 47-54页

作者： Feng Chen haibo xu Junhui Shi Xinge Li Na Zheng Zhejiang Lab Hangzhou 310000China Institute of Applied Physics and Computational Mathematics Beijing 100094China Graduate School of China Academy of Engineering Physics Beijing 100088China

Diagnosis of fluids is extremely significant at high temperatures and high pressures.As an advanced imaging technique,high-energy proton radiography has great potential for application to the diagnosis of high-density fluids.In high-energy proton radiography,an angular collimator can control the proton flux and thus enable material diagnosis and reconstruction of density.In this paper,we propose a multimaterial diagnostic method using angular collimators.The method is verified by reconstructing the density distribution from the proton flux obtained via theoretical calculations and numerical simulations.We simulate a 20 GeV proton imaging system using the Geant4 software toolkit and obtain the characteristic parameters of single-material objects.We design several concentric spherical objects to verify the method.We discuss its application to detonation tests.The results show that this method can determine the material and boundary information about each component of a multi-material object.Thus,it can be used to diagnose a mixed material and reconstruct densities in a detonation.

关键词： density. method. method

One Stone Two Birds-Enantioselective Bimetallic Catalysis forα-Amino Acid Derivatives with an Allene Unit

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Chinese Journal of Chemistry 2021年第7期39卷 1958-1964页

作者： Junzhe Xiao haibo xu Xiaohong Huo Wanbin Zhang Shengming Ma State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of Sciences345 Lingling LuShanghai200032 China University of Chinese Academy of Sciences Beijing100049 China Research Centre for Molecular Recognition and Synthesis Department of ChemistryFudan University220 Handan LuShanghai200433 China Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs School of Chemistry and Chemical Engineering and School of PharmacyShanghai Jiao Tong University800 Dongchuan RoadShanghai200240 China

Main observation and conclusion A highly enantioselective 2,3-allenylation of acyclic and cyclicα-imino carboxylates via a synergistic bimetallic Pd/Cu catalysis with the same commercially available(R,Rp)-iPr-FOXAP(also as Phosferrox,(R,R)-[2-(4’-i-propyloxazolin-2’-yl)ferrocenyl]diphenyl phosphine)ligand for both metals affording optically active 2,3-butadienylα-amino acid derivatives in high to excellent yields with excellent enantioselectivities has been developed.

关键词： Amino acids Allene Synergistic bimetallic Pd/Cu catalysis Enantioselective synthesis Mechanism

Artificial intelligence-based approaches for COVID-19 patient management

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Intelligent Medicine 2021年第1期1卷 10-15页

作者： Lan Lan Wenbo Sun Dan xu Minhua Yu Feng Xiao Huijuan Hu haibo xu Xinghuan Wang Department of Radiology Zhongnan Hospital of Wuhan UniversityNo.169 Donghu RoadWuchang DistrictWuhanHunan 430071China Center for Evidence-Based and Translational Medicine Zhongnan Hospital of Wuhan UniversityNo.169 Donghu RoadWuchang DistrictWuhanHunan 430071China Department of Urology Zhongnan Hospital of Wuhan UniversityWuhanHunan 430071China

During the highly infectious pandemic of coronavirus disease 2019(COVID-19),artificial intelligence(AI)has provided support in addressing challenges and accelerating achievements in controlling this public health crisis.It has been applied in fields varying from outbreak forecasting to patient management and drug/vaccine development.In this paper,we specifically review the current status of AI-based approaches for patient management.Limitations and challenges still exist,and further needs are highlighted.

关键词： Coronavirus disease 2019 Artificial intelligence