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Journal of Materials Science & Technology 2022年第15期110卷 239-245页

作者： jiaying jin Yongming Tao Xinhua Wang Zeyu Qian Wang Chen Chen Wu Mi Yan School of Materials Science and Engineering State Key Laboratory of Silicon MaterialsKey Laboratory of Novel Materials for Information Technology of Zhejiang ProvinceZhejiang UniversityHangzhou 310027China

Usually the improved coercivity of rare earth(RE)based 2:14:1-type permanent magnets via RE-rich intergranular additives is achieved at the cost of more corrosion channels and deteriorated corrosion resistance,which remains a challenging hurdle in the RE-Fe-B community.Distinctly,here we report the concurrent improvements of corrosion resistance and coercivity in 40 wt.%Ce-substituted Nd-Ce-Fe-B sintered magnets through engineering the intergranular phase using simple(Nd,Pr)H_(x)additive.The dehydrogenated Nd/Pr changes the RE concentration gradients between 2:14:1 matrix and intergranular phases during sintering and enlarges the fraction of corrosion-resistant REFe_(2) phase,rather than the conventionally assumed Nd/Pr-rich intergranular phase with high chemical vulnerability.The spontaneous formation of REFe_(2) intergranular phase after(Nd,Pr)H_(x) addition generates the uniquely enhanced corrosion resistance against the hot/humid and acidic environments,and counts as one peculiar feature of Nd-Ce-Fe-B magnets at high Ce substitution level,being distinct from previously reported Ce-free/lean RE-Fe-B.Simultaneously,the formation of continuous grain boundaries enhances the coercivity from 8.7to 12.5 k Oe with trace addition of(Nd,Pr)H_(x).Above findings may spur progress towards developing a high-performance Nd-Ce-Fe-B permanent magnet.

关键词： Abundant rare earth Ce Corrosion resistance REFe_(2) Coercivity Microstructure

Exchange interaction and demagnetization process of high-abundance rare-earth magnets sintered using dual alloy method

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Science China(Physics,Mechanics & Astronomy) 2022年第4期65卷 104-111页

作者： Dan Liu Tongyun Zhao jiaying jin Tianyu Ma Jiefu Xiong Baogen Shen Fengxia Hu Jirong Sun Department of Physics School of Artificial IntelligenceBeijing Technology and Business UniversityBeijing 100048China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou 341000China State Key Laboratory of Magnetism Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China

The 2:14:1-type rare-earth(RE)-Fe-B permanent magnets prepared by the dual alloy method have been found to possess much superior magnetic properties to those prepared by the single alloy method,providing an appealing route to promote the utilization of high-abundance RE elements Ce and La and balance the use of the RE source.However,the relationship between magnetic interactions among different 2:14:1 main phases and superior magnetic properties is still unclear.In this study,we investigated the magnetic interactions and reversal field distribution in these magnets using first-order reversal curve(FORC)images.The FORC images showed that(Nd,Pr)27.8(La,Ce)2.7FebalM1.4B1.0(S-9)and(Nd,Pr)19.5(La,Ce)11.0FebalM1.4B1.0(S-36)have the characteristics of multiple main phases.The reverse magnetic fields corresponding to the soft and hard main phases,as well as the associated exchange coupling,were highly dependent on the La Ce content.The higher the La Ce content,the weaker the exchange coupling and the more asynchronous the demagnetization process.In addition,the FORC images indicated that the magnetization reversal process also varies with La Ce content,where the nucleation and propagation of reversed domains dominant in the S-9 magnet,while the domain propagation in the S-36 magnet is considerably suppressed.Additional micromagnetic simulations also revealed that the coercivity and exchange coupling of multi-main-phase magnets decrease with increasing La Ce content,correlating well with the experimental results.These findings may not only contribute to a better understanding of the complex magnetic interactions between the soft and hard phases and how they affect macroscopic magnetic properties but also help in improving the magnetic performance of the RE-Fe-B magnets with high La Ce content.

关键词： permanent magnets exchange interaction first-order reversal curve micromagnetism high abundance rare-earth magnets

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沿海省域海陆生产要素配置效率估算及其优化

经济地理 2024年第3期44卷 11-21页

作者：靳来群戴佳颖余璇宁波大学商学院浙江宁波315021 宁波大学东海研究院浙江宁波315021

文章基于2006—2019年的省级面板数据,通过构建全国—省份—陆海三层架构的一般均衡模型,测算了沿海11个省份内部以及省际因海陆生产要素配置扭曲而造成的全要素生产率(TFP)损失程度,并分析了其演化趋势。结果表明:(1)2019年我国整体海... 详细信息

文章基于2006—2019年的省级面板数据,通过构建全国—省份—陆海三层架构的一般均衡模型,测算了沿海11个省份内部以及省际因海陆生产要素配置扭曲而造成的全要素生产率(TFP)损失程度,并分析了其演化趋势。结果表明:(1)2019年我国整体海陆间生产要素配置扭曲导致TFP损失了2.68%。与陆地经济相比,各省份在海洋经济上的要素投入仍然不足,尤其是天津、河北、山东、上海、江苏、福建等地区有高达40%以上的投入缺口。(2)省际海洋生产要素配置扭曲导致TFP损失高达6.18%,远高于同期陆地生产要素的错配,且存在逐年加重的趋势。(3)从各省份的海洋生产要素投入来看,劳动要素中辽宁、广西、海南投入过度,上海、江苏、福建等地的投入均不足;资本要素中天津、辽宁存在一半以上过剩,而上海、江苏、浙江由于自身海洋经济的快速发展,其现有资本投入处于相对短缺状态。各省份应进一步提高海洋部门生产要素投入,以促进陆地和海洋的协调发展,加快建设全国统一大市场中的陆海统筹。

关键词：海洋经济资源错配要素投入力度劳动与资本陆海统筹

High-frequency MnZn soft magnetic ferrite by engineering grain boundaries with multiple-ion doping

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Journal of Materials Science & Technology 2021年第20期79卷 165-170页

作者： Mi Yan Shengbo Yi Xiuyuan Fan Zhenghua Zhang jiaying jin Guohua Bai Institute of Advanced Magnetic Materials College of Materials&Environmental EngineeringHangzhou Dianzi UniversityHangzhou310018China School of Materials Science and Engineering State Key Laboratory of Silicon MaterialsKey Laboratory of Novel Materials for Information Technology of Zhejiang ProvinceZhejiang UniversityHangzhou310027China

MnZn soft magnetic ferrites have been widely utilized in power electronics,owing to the combined merits of high permeability and low energy loss.However,their deployment would result in a drastic increase in power dissipation at>3 MHz,thus limiting the scope extent of miniaturization,together with their efficiency.Here,we report a high-performance MnZn ferrite by doping multiple ions(La,Ti,Si,Ca)at grain boundaries,achieving the most optimized power loss of 267 kW/m^(3) at 5 MHz(10 m T,100℃)and initial permeability of 644,which is much better than the previously reported results and commercial products.Such an improvement is attributed to weakened magnetic exchange coupling at grain-boundary regions,associated with a significant transition from the multi-to mono-domain structures,originating physically from large crystallographic mis-orientations(>25°).The present study bears important significance in understanding the intrinsic correlation between the crystallographic mis-orientation and magnetic domain structure,and provides an alternative way for optimizing high-frequency soft magnetic ferrites.

关键词： MnZn ferrite Multi-ion doping MHz application Grain size Crystallographic mis-orientations

Promoting the La solution in 2:14:1-type compound:Resultant chemical deviation and microstructural nanoheterogeneity

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Journal of Materials Science & Technology 2021年第3期62卷 195-202页

作者： Yongsheng Liu jiaying jin Tianyu Ma Baixing Peng Xinhua Wang Mi Yan School of Materials Science and Engineering State Key Laboratory of Silicon materialsKey Laboratory of Novel Materials for Information Technology of Zhejiang ProvinceZhejiang UniversityHangzhou310027China

RE_(2)Fe_(14)B-based(RE,rare earth)permanent magnets containing abundant and cheap La/Ce have attracted intense attention recently.In comparison with Ce that can fully replace Nd in the 2:14:1 lattice,La substitution for Nd has long been limited at a low level.Here we present that through doping La35 Ce65 alloy with the La/Ce ratio in natural mineral,stable 2:14:1 phase can be maintained at 1273 K within the entire substitution range of[(La_(35)Ce_(65))、(Pr_(20)Nd_(80))_(1-x)]_(2.14)Fe_(14)B(0.6≤x≤1.0,at.%),as verified by composition analysis,microstructural characterization and magnetic measurements.Interestingly,the promoted La solution in 2:14:1 phase induces two unique findings upon coexisting La-Ce-Pr-Nd:i)Compared to Ce that fits well with the nominal concentration,La deviates noticeably from the nominal one;ii)Nanoscale spinodal-decomposition-like phase separation is observed due to different solubilities of La-Ce-Pr-Nd elements in 2:14:1 phase.Above joint effects induce higher Curie temperature than estimation based on the rule of mixture,which delights the prospect of La_(35)Ce_(65)alloy in developing low-cost permanent materials.

关键词： La-Ce Permanent magnets Nd-Fe-B Microstructure

增强现实眼镜对人眼工作效率和视疲劳影响的研究

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中华眼科杂志 2024年第4期60卷 352-358页

作者：许泽华吴晋芳雷家颖金子兵首都医科大学附属北京同仁医院北京同仁眼科中心、北京市眼科研究所、北京市眼科学与视觉科学重点实验室北京100730

目的探讨使用增强现实眼镜与笔记本电脑在阅读效果和视疲劳方面的差异。方法前瞻性自身对照研究。于2023年11月1至15日在首都医科大学附属北京同仁医院招募长期近距离视物且高频使用笔记本电脑等数字显示设备的健康首都医科大学学生作... 详细信息

目的探讨使用增强现实眼镜与笔记本电脑在阅读效果和视疲劳方面的差异。方法前瞻性自身对照研究。于2023年11月1至15日在首都医科大学附属北京同仁医院招募长期近距离视物且高频使用笔记本电脑等数字显示设备的健康首都医科大学学生作为受试者, 检测视力、双眼视功能(调节、集合、融合功能等)和视疲劳评分(Likert视疲劳量表)。采用抛硬币法确定受试者笔记本电脑和增强现实眼镜的使用顺序, 分别于不同日期的相同时间段检测使用不同设备10 min的阅读效率(阅读速度和错误数字对检出率的乘积), 以及观看20 min视频后的视疲劳评分。采用配对样本t检验和Wilcoxon秩和检验进行统计学分析。结果共纳入20名符合标准的受试者, 男性7名, 女性13名, 年龄为(25.45±2.27)岁。使用增强现实眼镜和笔记本电脑前后, 受试者双眼的远视力均未发生显著变化(均P>0.05)。使用增强现实眼镜的阅读速度和阅读效率[(34.03±9.25)和(29.19±7.62)数字对/min]显著低于使用笔记本电脑[(39.43±10.36)和(35.67±9.87)数字对/min](t=4.36, P<0.001), 但错误数字对检出率差异无统计学意义(t=1.29, P=0.213)。使用2种设备观看视频前的视疲劳评分差异无统计学意义(Z=-0.71, P=0.480), 使用增强现实眼镜观看视频后的视疲劳评分[(20.55±5.04)分]显著高于使用笔记本电脑[16.50(13.00, 19.75)分](Z=-2.85, P=0.004)。使用2种设备观看视频后的视疲劳评分均较观看前显著升高(P<0.05), 其中使用增强现实眼镜的视疲劳评分升高[(6.05±3.50)分]更显著(Z=-3.41, P<0.001)。结论与使用笔记本电脑比较, 使用现有增强现实眼镜进行阅读的速度和效率较低, 使用后视疲劳程度较重, 增强现实眼镜技术尚待进一步优化和改进。

关键词：眼疲劳眼镜阅读效率视敏度

低共熔溶剂双水相萃取-UPLC法检测吸烟者尿液中杂环胺类化合物

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高等学校化学学报 2024年第3期45卷 47-54页

作者：李敏贺姗姗王宏宇庄家莹金永日李绪文郑州轻工业大学食品与生物工程学院郑州450001 吉林大学化学学院长春130012

为评估香烟烟气中杂环胺的暴露水平,建立了一种基于低共熔溶剂/无机盐双水相萃取-UPLC法测定吸烟者尿液中5种杂环胺(IQ,IQ[4,5-b],Harman,Norharman和Phe-P-1)的方法.制备了7种以氯化胆碱(ChCl)为氢键受体的低共熔溶剂,并对其进行了表征... 详细信息

为评估香烟烟气中杂环胺的暴露水平,建立了一种基于低共熔溶剂/无机盐双水相萃取-UPLC法测定吸烟者尿液中5种杂环胺(IQ,IQ[4,5-b],Harman,Norharman和Phe-P-1)的方法.制备了7种以氯化胆碱(ChCl)为氢键受体的低共熔溶剂,并对其进行了表征;系统考察了影响萃取效率的主要参数,并将该方法与其它方法进行了对比研究.结果表明,在最佳提取条件下,杂环胺(HAAs)的回收率为81.9%~106.2%,日内和日间精密度分别低于2.9%和3.2%,检出限和定量限分别为0.020~0.097 ng/g和0.19~0.39 ng/g.该方法具有操作简单、环境友好及单样品成本低等特点,为尿液中杂环胺的检测提供了一种新方法,在生物样品检测领域具有良好的开发与应用价值.

关键词：杂环胺低共熔溶剂双水相萃取尿液

Classification and Prediction of Skyrmion Material Based on Machine Learning

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Research 2023年第4期2023卷 281-291页

作者： Dan Liu Zhixin Liu jinE Zhang Yinong Yin Jianfeng Xi Lichen Wang JieFu Xiong Ming Zhang Tongyun Zhao jiaying jin Fengxia Hu Jirong Sun Jun Shen Baogen Shen Department of Physics School of Artificial IntelligenceBeijing Technology and Business UniversityBeijing 100048P.R.China School of Integrated Circuit Science and Engineering Beihang UniversityBeijing 100191China Ningbo Institute of Materials Technology&EngineeringChinese Academy of SciencesZhejiang 315201P.R.China School of Physics Inner Mongolia University of Science and TechnologyBaotou 014010P.R.China State Key Laboratory of Magnetism Institute of PhysicsChinese Academy of SciencesBeijing 100190P.R.China School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027P.R.China Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190P.R.China

The discovery and study of skyrmion materials play an important role in basic frontier physics research and future information technology.The database of 196 materials,including 64 skyrmions,was established and predicted based on machine learning.A variety of intrinsic features are classified to optimize the model,and more than a dozen methods had been used to estimate the existence of skyrmion in magnetic materials,such as support vector machines,k-nearest neighbor,and ensembles of trees.It is found that magnetic materials can be more accurately divided into skyrmion and non-skyrmion classes by using the classification of electronic layer.Note that the rare earths are the key elements affecting the production of skyrmion.The accuracy and reliability of random undersampling bagged trees were 87.5%and 0.89,respectively,which have the potential to build a reliable machine learning model from small data.The existence of skyrmions in LaBaMnO is predicted by the trained model and verified by micromagnetic theory and experiments.

关键词： frontier earths verified

海巴戟果实软化相关基因McXTH的克隆和表达分析

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四川农业大学学报 2024年第1期42卷 94-102页

作者：李佳莹宫树森秦英金璨吴田西南林业大学园林园艺学院昆明650224

【目的】了解诺丽果实软化规律,克隆木葡聚糖内转糖苷酶/水解酶(XTH)基因,初步明确其表达模式。【方法】用果实硬度计测量后熟阶段的诺丽果实在25℃放置及乙烯利处理两种状态下的硬度变化。从诺丽果实采后0~48 h转录组数据中筛选差异表... 详细信息

【目的】了解诺丽果实软化规律,克隆木葡聚糖内转糖苷酶/水解酶(XTH)基因,初步明确其表达模式。【方法】用果实硬度计测量后熟阶段的诺丽果实在25℃放置及乙烯利处理两种状态下的硬度变化。从诺丽果实采后0~48 h转录组数据中筛选差异表达的XTH候选基因。通过生物信息学分析,克隆目的基因全长,并利用荧光定量PCR技术分析基因表达模式,同时用便携式乙烯测量仪测定内源乙烯释放量。【结果】后熟阶段的海巴戟果实采后表皮硬度随贮藏时间增加而下降,且乙烯利处理后的软化趋势较室温自然放置更为显著。从海巴戟果实采后0~48 h转录组数据中筛选出基因XTH(DN16278g1)的表达量高、差异大。该基因具有完整的开放阅读框(ORF),克隆测序后将其命名为McXTH,并将其提交Genbank获得登录号为ON512442。McXTH基因ORF全长1062 bp,共编码353个氨基酸,与其他植物中的XTH基因氨基酸序列的相似性为75%~88%。RT-qPCR结果和内源乙烯释放量表明,在海巴戟果实成熟阶段McXTH的表达量与同时期的内源乙烯释放量在趋势上大体相同。【结论】海巴戟果实的软化受乙烯和关键基因XTH调控,Mc XTH的克隆为进一步进行XTH基因在海巴戟果实成熟软化过程的功能研究夯实基础。

关键词：海巴戟木葡聚糖内转糖苷酶/水解酶(XTH) 果实软化果实成熟乙烯

BTA@HMCs/PANI微胶囊的制备及环氧涂层防腐性能

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高分子材料科学与工程 2024年第4期40卷 50-60页

作者：张琲瑶李鑫石楠奇周锐金佳赢李海燕东北石油大学化学化工学院黑龙江省聚烯烃新材料重点实验室黑龙江大庆163318

以硬模板法合成的中空介孔碳球(HMCs)为微容器,通过真空浸渍及原位聚合法成功制得负载缓蚀剂苯并三氮唑(BTA)的BTA@HMCs/PANI微胶囊。制备的微胶囊呈规则球形,平均粒径约为270nm,壁厚(50±10)nm,微胶囊芯材质量分数为31.0%。添加质量分... 详细信息

以硬模板法合成的中空介孔碳球(HMCs)为微容器,通过真空浸渍及原位聚合法成功制得负载缓蚀剂苯并三氮唑(BTA)的BTA@HMCs/PANI微胶囊。制备的微胶囊呈规则球形,平均粒径约为270nm,壁厚(50±10)nm,微胶囊芯材质量分数为31.0%。添加质量分数5%BTA@HMCs/PANI微胶囊的自修复环氧涂层具有最佳的防腐性能,盐水浸泡实验表明环氧复合涂层浸泡30d后无明显腐蚀现象,电化学阻抗实验表明,环氧复合涂层低频区的阻抗模量值较纯环氧涂层高2~3个数量级。文中同时揭示了微胶囊芯材腐蚀抑制剂BTA和微胶囊壁材聚苯胺(PANI)协同防腐机理。

关键词：中空介孔碳球微胶囊自修复涂层防腐性能