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magnetic properties and microstructure of nanocrystalline bulk Nd-Fe-B with Ce-Co addition

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Journal of Rare Earths 2021年第6期39卷 689-695,I0003页

作者： Yilong ma Qiqi Yang Xiaoli Chen Ying He Wenbo Xiang Jiaqi Lai Bin Shao Donglin Guo Dengming Chen Kejian Li College of metallurgy and materials Engineering Chongqing University of Science and TechnologyChongqing 401331China The Center of material Analysis and Testing Chongqing University of Science and TechnologyChongqing 401331China

The influence of Ce-Co alloy addition and sintering holding time on permanent magnetic properties and micro structure of nanocrystalline Nd-Fe-B bulk alloy were *** coercivity of Nd-Fe-B bulk alloy can be enhanced greatly by more than 100% after adding Ce-Co ***,when the concentration of Ce-Co is up to 30 wt%,the density of the magnet can reach the maximum value of 7.58 g/cm^(3),but the coercivity does not increase *** the other hand,with the increase of holding time to 10 min,the density and coercivity of magnets increase gradually,reaching up to 7.55 g/cm^(3) and 1134.3 ka/m,*** the addition of Ce-Co alloy,Ce-Co may easily diffuse into the Nd-Fe-B matrix during hot-pressing and under the high pressure and temperature,thus increasing the content of grain boundary phase and the pinning effect of grain boundary,which leads to the increase of *** extension of the hot-pressing holding time may be more conducive to the diffusion of CeCo into the Nd-Fe-B *** addition,the effect of Ce-Co addition on the magnetic properties of Nd-FeB with different content of rare earth was also *** addition of Ce-Co can effectively increase the coercivity of nanocomposite Nd_(2)Fe_(14)B/α-Fe *** addition of Nb to the parent alloy can further improve the *** Nd_(11)Fe_(81.5)Nb_(1)Ga_(0.5)B_(6) alloy with 10 wt% Ce-Co addition,the coercivity can increase from 740.28 to 1098.48 ka/m.

关键词： Nd-Fe-B magnet Ce-Co addition Coercivity microstructure Nanocomposite Rare earths

基于SEER数据库构建肝细胞癌患者预后预测新模式

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兰州大学学报（医学版） 2024年第5期50卷 41-48,55页

作者：王霄杨波马晨哲汪营营杨庆娥李玉民兰州大学第二临床医学院甘肃兰州730030 甘肃省环境肿瘤学重点实验室甘肃兰州730030

目的研究肝细胞癌患者总生存期的影响因素,构建新的预测模式,为患者的个体化和精准化治疗方案提供理论支持和参考。方法在SEER数据库中获取2011—2015年被诊断为肝细胞癌的患者数据,运用单因素和多因素Cox回归分析筛选预后因素并构建预... 详细信息

目的研究肝细胞癌患者总生存期的影响因素,构建新的预测模式,为患者的个体化和精准化治疗方案提供理论支持和参考。方法在SEER数据库中获取2011—2015年被诊断为肝细胞癌的患者数据,运用单因素和多因素Cox回归分析筛选预后因素并构建预测模型。采集兰州大学第二医院280例肝细胞癌患者样本数据,作为外部验证队列。应用一致性指数、受试者操作特征曲线、校准曲线、决策曲线评估模型效能并与传统TNm分期进行对比,计算分数对患者进行危险分层并绘制小提琴图。结果回归分析提示年龄、性别、N分期、m分期、甲胎蛋白表达情况、手术情况、放射治疗、化学治疗是影响肝细胞癌患者总生存期的独立预后因素。训练组的一致性指数为0.739(95%Ci:[0.730,0.748]),1、3、5年患者总生存期受试者操作特征曲线下面积分别为0.806、0.811、0.812;内部验证组的一致性指数为0.732(95%Ci:[0.718,0.746]),1、3、5年患者总生存期受试者操作特征曲线下面积分别为0.787、0.803、0.810;外部验证组的一致性指数为0.719(95%Ci:[0.684,0.753]),1、3、5年患者总生存期受试者操作特征曲线下面积分别为0.794、0.841、0.899;传统TNm模型的一致性指数为0.704(95%Ci:[0.691,0.714]),1、3、5年患者总生存期受试者操作特征曲线下面积分别为0.716、0.687、0.677。决策曲线显示列线图较传统TNm分期预测效能更好。结论本研究构建的列线图能够用于预测肝细胞癌患者的总生存期,且效果优于传统TNm分期,基于新的预测模型的危险分层系统在区分患者生存期时更精确,对肝细胞癌患者的个体化治疗具有临床参考价值。

关键词：肝细胞癌总生存期 SEER数据库预测模型列线图预后

SiS accuracy and service performance of the BDS-3 basic system

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Science China(Physics,mechanics & Astronomy) 2020年第6期63卷 105-116页

作者： JinPing Chen XiaoGong Hu ChengPan Tang ShanShi Zhou YuFei Yang JunYang Pan Hui Ren YueXin ma QiuNing Tian Bin Wu Yang Yu Beijing Satellite Navigation Center Beijing 100094China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Shanghai Key Laboratory for Space Positioning and Navigation Shanghai 200030China

On December 27,2018,the basic system of the third-generation BeiDou navigation satellite system(BDS-3)completed the deployment of its constellation of 18 mEO networking satellites as well as the construction of the operation control system(OCS)and began to provide basic navigation services to users *** with BDS-2,BDS-3 aims to offer users better navigation signals and higher precision with a series of new *** example,the spaceborne atomic clock of BDS-3 is upgraded for higher performance,the ka-band inter-satellite link is adopted for inter-satellite ranging and communication,and new B1C and B2a signals are broadcast in addition to B1i and B3i signals(compatible with BDS-2).in addition,a 9-parameter model based on a spherical harmonic function is employed for ionospheric delay *** the observation data from 18 satellites of the basic system,this paper conducts a comprehensive evaluation of the pseudorange measurement characteristics,signal-in-space(SiS)accuracy of navigation messages and global service capability of *** results indicate that the pseudorange measurement multipath effect and observation noise of BDS-3 satellites are better than those of BDS-2;additionally,with the support of inter-satellite links,the user range error(URE)of the BDS-3 satellite broadcast ephemeris is better than 10 cm,the precision of the broadcast clock parameter is better than 1.5 ns,and the SiS accuracy is better than 0.6 m *** from the traditional Klobuchar model,the BeiDou global broadcast ionospheric delay correction model(BDGim)can provide ionospheric delay corrections better than 70%for worldwide single-frequency *** service capability evaluation of the basic system consists mainly of the accuracy improvement of the B1i and B3i signals according to BDS-2 as well as the global positioning accuracy of the new *** results prove that the BDS-3 basic system has achieved the design goal;that is,both the hori

关键词： BDS-3 SiS URE multipath effect broadcast ephemeris broadcast clock ionospheric model positioning accuracy

二维斑点追踪超声心动图评估慢性心力衰竭患者左心房心肌力学变化

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中华实用诊断与治疗杂志 2024年第6期38卷 623-628页

作者：刘会若宋毅张艳张姗马丹珂吴婷郑璐郑州大学第一附属医院郑东院区超声科河南郑州450046 郑州大学第一附属医院郑东院区心内科河南郑州450046

目的观察慢性心力衰竭患者左心房心肌力学变化,探讨二维斑点追踪超声心动图(2D-STE)对其的评估作用。方法 2022年10月—2023年12月郑州大学第一附属医院诊治慢性全心衰竭(CBHF)患者87例(CBHF组)和慢性左心衰竭(CLHF)患者85例(CLHF组),... 详细信息

目的观察慢性心力衰竭患者左心房心肌力学变化,探讨二维斑点追踪超声心动图(2D-STE)对其的评估作用。方法 2022年10月—2023年12月郑州大学第一附属医院诊治慢性全心衰竭(CBHF)患者87例(CBHF组)和慢性左心衰竭(CLHF)患者85例(CLHF组),均行常规超声心动图检查,平静状态下采集连续5个心动周期的二维灰阶动态图像。于局部放大的胸骨旁左心室长轴切面上,参照心电图,测量二尖瓣环与主动脉瓣环平面最大夹角(Ama.a.)和最小夹角(Amamin),计算角度变化率。采用Simpson’s双平面法测量左室射血分数(LVEF)、左心室舒张末期容积(LVEDV)、左心室收缩末期容积(LVESV)、左心房容积指数(LAVi),测量室间隔侧电-机械传导时间(TiVS P-a)、侧壁侧电-机械传导时间(TLW P-a)、舒张期二尖瓣口前向血流速度E峰、A峰及舒张早期运动峰值速度e’,计算E/e’,并评估二尖瓣反流程度。应用超声定量分析软件获取左心室整体纵向应变(LVGLS)及左心房储存期应变(LASr)、管道期应变(LAScd)、收缩期应变(LASct)。采用多元线性回归分析CBHF、CLHF患者LASr、LASct的影响因素,采用Pearson法或Spearman法分析2组LASr、LASct与LVGLS、LAVi的相关性。结果 CBHF组收缩压[127.00(115.01,139.11)mmHg]低于CLHF组[132.00(122.12,142.30)mmHg](Z=-2.143,P=0.032),TLW P-a[45.00(32.00,57.00)ms]长于CLHF组[30.00(26.00,39.00)ms](Z=-3.749,PmL]、LAVi[(64.85±1.72)mL/m^(2)]均大于CLHF组[164.00(143.50,182.00)mL、(57.98±1.54)mL/m^(2)](Z=-2.156,P=0.031;t=2.967,P=0.003),二尖瓣反流中、重度比率(42.53%、34.48%)高于CLHF组(36.47%、17.65%)(χ^(2)=7.493,P=0.007;χ^(2)=8.763,P=0.007),体质量指数、心率、舒张压、E峰、A峰、E/e’、TiVS P-a、Ama.a.、Amamin、角度变化率、LVEF、LVEDV及高血压、糖尿病比率与CLHF组比较差异均无统计学意义(P>0.05)。CBHF组LVGLS[(-7.00±0.00)%]、LASr[8.00(6.00,10.00)%]、LASct[(-2.00±0.00)%]绝对值均低于CLHF组[(-8.00±0.00)%、9.80(7.60,12.30)%、(-4.00±0.00)%](P0.05)。LVGLS是CBHF、CLHF患者LASr的影响因素(β=-0.430,95%Ci:-0.771~-0.088,P=0.014;β=-0.304,95%Ci:-0.605~-0.003,P=0.048),LAVi、LVGLS是CLHF患者LASct的影响因素(β=0.001,95%Ci:0.000~0.001,P=0.004;β=0.285,95%Ci:0.065~0.506,P=0.012)。CBHF组、CLHF组LASr与LVGLS均呈负相关(r=-0.321,P=0.005;r=-0.217,P=0.046),CLHF组LASct与LAVi、LVGLS均呈正相关(r=0.246,P=0.023;r=0.228,P=0.036)。结论 CBHF患者LAVi增高,二尖瓣环TLW P-a延长,LASr随LVGLS增大而降低;2D-STE可评估慢性心力衰竭患者左心房心肌力学变化。

关键词：慢性心力衰竭二维斑点追踪超声心动图左心房心肌力学

渔网超结构的等离激元模式及其对薄膜电池的陷光调控

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物理学报 2021年第21期70卷 385-390页

作者：姜悦王淑英王治业周华卡马勒赵颂沈向前新疆大学物理科学与技术学院新疆固态物理与器件重点实验室乌鲁木齐830046 山东大学物理学院济南250100

渔网超结构具有平面、近光学无损、特定光场中可以激发表面等离激元等特点,在增强光子器件的响应效率方面极具潜力.本文基于时域有限差分方法和严格耦合波分析,系统研究了渔网超结构的等离共振模式及其对晶硅薄膜电池的光波调控性能.研... 详细信息

渔网超结构具有平面、近光学无损、特定光场中可以激发表面等离激元等特点,在增强光子器件的响应效率方面极具潜力.本文基于时域有限差分方法和严格耦合波分析,系统研究了渔网超结构的等离共振模式及其对晶硅薄膜电池的光波调控性能.研究结果表明,渔网结构对光波的吸收、散射和消光特性强烈依赖金属层的厚度、线宽、周期等特征参数.通过优化设计,使共振峰红移至770 nm,相对消光截面达到1.69,同时散射光在消光光谱中占据主导地位.以此构筑的响应层厚度为2μm的晶硅薄膜电池在波长大于800 mm的波段吸收效率显著增强,电池最终的能量转换效率从6.67%提高到了8.25%.光强分布显示,共振导致的背向散射增强和光子传播方向的大角度偏转是实现电池响应增益的重要原因.

关键词：渔网超结构等离激元光学调控能量效率

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微细粒铁尾矿浮选回收萤石工艺试验研究

非金属矿 2024年第5期47卷 65-68页

作者：张鹏羽杨卓赵强马钟琛喻明军李文涛中冶长天国际工程有限责任公司湖南长沙410205 中南大学资源加工与生物工程学院湖南长沙410083

某选铁尾矿细泥中含少量萤石矿物资源。基于工艺矿物学分析,本试验提出萤石磁浮联合工艺,实现了微细粒选铁尾矿中低品位萤石的高效回收。结果表明,铁尾矿-0.038 mm占比76.97%,经磁场强度636.8 ka/m强磁选可抛除42.89%磁性脉石矿物,CaF_... 详细信息

某选铁尾矿细泥中含少量萤石矿物资源。基于工艺矿物学分析,本试验提出萤石磁浮联合工艺,实现了微细粒选铁尾矿中低品位萤石的高效回收。结果表明,铁尾矿-0.038 mm占比76.97%,经磁场强度636.8 ka/m强磁选可抛除42.89%磁性脉石矿物,CaF_(2)品位由13.91%提至21.04%;采用碳酸钠作为调整剂,酸化水玻璃为抑制剂,改性脂肪酸作为捕收剂进行浮选,最终获得产率为7.81%、CaF_(2)品位为90.72%、CaF_(2)回收率为50.94%的萤石精矿产品。

关键词：微细粒铁尾矿萤石磁选浮选精矿

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Achievement of high performance of sintered R-Fe-B magnets based on misch metal doped with PrNd nanoparticles

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Rare metals 2018年第3期37卷 237-242页

作者： Qiang ma Jian-Teng Zhu Xue-Feng Zhang Zeng-Ru Zhao Yan-Li Liu Gao-Feng Wang Yong-Feng Li Zhu-Bai Li Key Laboratory of integrated Expoitation of Bayan Obo multimetal Resources Inner Mongolia University of Science and Technology College of Science Inner Mongolia University of Science and Technology

The magnetic properties and microstructure of sintered R-Fe-B（R, rare earth） magnets with nominal composition of（（PrNd）（1-x）mmx）（30）Fe（bal）B1（x = 0, 0.***.0.2,0.3, 0.4, 0.5 and 0.7; mm, misch metal） prepared using dual-alloy method were investigated. For x = 0.3, the maximum energy product（（BH）（max）） of the sintered magnet is higher than 318.4 kJ·m^-3,but intrinsic coercivity（H（cj）） is lower than 351.8 ka·m^-1. The La and Ce contents are obviously different in some matrix-phase grains, which proves that the multi-hard magnetic phases（La, Ce-rich and La, Ce-lean） exist in the magnets. The coercivity is improved by the method of doping PrNd nanoparticles without sacrificing other magnetic properties. An enhancement in coercivity from 517.2 to 872.9 ka·m^-1 is achieved by doping 5 wt% PrNd nanoparticles. meanwhile, it could exhibit better magnetic properties（remanence Br = 1.332 *** coercivity H（cj）= 872.9 ka·m^-1 maximum energy product（BH）（max）=318.6 kJ·m^-3） and make the distribution of the intergranular phase become more homogeneous.

关键词： Permanent magnetic materials Nanoparticles misch metal Dual-alloy Coercivity

magnetic properties of melt-spun mm-Fe-B ribbons with different wheel speeds and mischmetal contents

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Rare metals 2017年第12期36卷 992-996页

作者： Xue-Feng Zhang Wen-kai Zhang Yong-Feng Li Yan-Li Liu Zhu-Bai Li Qiang ma meng-Fei Shi Fei Liu Key Laboratory of integrated Exploitation of Bayan Obo multi-metal Resources Inner Mongolia University of Science andTechnology Baotou 014010 China Schools of mathematics Physics and Biological EngineeringInner Mongolia University of Science and TechnologyBaotou 014010 China

in this study, the effect of wheel speed and mischmetal（mm） content on the magnetic properties of mmFeB ribbons was investigated. The samples were prepared via direct solidification technique. The nominal composition of the alloy ingots is mm;Fe;B;with x varying from 9 to 15 in steps of 2. Experimental results show the overall magnetic properties of the *** of the results shows that the magnetic properties first improve and then degrade with the wheel speed and mm content increasing. increase in mm content leads to better formation of crystal texture in the ribbons, indicating that the a-Fe phase might undermine the formation of crystal texture. magnetic properties results show that the coercivity of the ribbons rises with an appropriate increase in both mm content and wheel speed during melt-spun process. The strongest magnetic properties of the ribbons(remanence of m;= 0.72 T, intrinsic coercivity of H;= 352.58 ka·m;, and maximum energy product of（BH）;=72.14 kJ·m;) are obtained for compositions where x = 13 and a wheel speed of v = 20 m·s;.

关键词： mischmetal mmFeB magnetic properties melt spun

Dexamethasone ameliorates severe pneumonia but slightly enhances viral replication in the lungs of SARS-CoV-2-infected Syrian hamsters

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Cellular & molecular immunology 2022年第2期19卷 290-292页

作者： Lunzhi Yuan ming Zhou Jian ma Xuan Liu Peiwen Chen Huachen Zhu Qiyi Tang Tong Cheng Yi Guan Ningshao Xia State Key Laboratory of molecular Vaccinology and molecular Diagnostics National Institute of Diagnostics and Vaccine Development in Infectious DiseasesSchool of Life SciencesSchool of Public HealthXiamen UniversityXiamenFujianChina. State Key Laboratory of Emerging infectious Diseases School of Public HealthLi Ka Shing Faculty of MedicineThe University of Hong KongHong KongSARChina. Guangdong-Hong Kong Joint Laboratory of Emerging infectious Diseases/Joint Laboratory for international Collaboration in Virology and Emerging infectious Diseases Joint Institute of Virology(STU/HKU)Shantou UniversityShantouGuangdongChina. EKiH Pathogen Research institute Futian DistrictShenzhenGuangdongChina. Department of microbiology Howard University College of MedicineWashingtonDCUSA. Research Unit of Frontier Technology of Structural Vaccinology Chinese Academy of Medical SciencesXiamenFujianChina.

The pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in more than 230 million cases and over four million deaths ***,multiple emerging SARS-CoV-2 variants have shown enhanced infectivity,transmissibility,pathogenicity and ability to escape neutralization by vaccine-induced humoral immunity[1].The antibody resistance of SARS-CoV-2 variants constitutes a challenge for current vaccines and therapeutic *** specific antiviral is currently available for coronavirus in humans[2].Although remdesivir was approved by the FDA for the treatment of SARS-CoV-2 infection,the therapeutic effect is limited,particularly for critical cases with severe pneumonia.

关键词： immunity pneumonia vaccine