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改进的比幅式工频变化量距离继电器方案

电力系统自动化 2006年第9期30卷 56-60页

作者：邰能灵林韩陈金祥 ing.j.stenzel 上海交通大学电子信息与电气工程学院上海市200030 福建省电力有限公司福建省福州市350003 福建省电力试验研究院系统所福建省福州市350007 Darmstadt工业大学电气工程系

从实用的角度出发,提出改进的比幅式工频变化量距离继电器方案。通过综合阻抗继电器和电抗继电器的优点,即适当调整补偿电压故障量的大小,使新方案具有一定的耐受过渡电阻能力和抗干扰能力。对受端继电器,提出仅利用保护安装处的电压变... 详细信息

从实用的角度出发,提出改进的比幅式工频变化量距离继电器方案。通过综合阻抗继电器和电抗继电器的优点,即适当调整补偿电压故障量的大小,使新方案具有一定的耐受过渡电阻能力和抗干扰能力。对受端继电器,提出仅利用保护安装处的电压变化值构成同相点切换判据,可以有效降低系统参数的影响。由于同相点切换后,保护判据动作方程改变,因此在同相点前后,补偿电压的调整方向应该相反。仿真结果表明,弱电抗分量电抗继电器方案具有较好的性能,并且其保护范围和反应接地电阻的能力可以通过改变补偿电压值进行调节。

关键词：距离保护故障分量高阻接地故障阻抗继电器电抗继电器

临床-超声列线图预测急性缺血性脑卒中短期预后

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中国介入影像与治疗学 2024年第6期21卷 338-342页

作者：苏航周志刚李菁郑州大学第一附属医院超声科河南郑州450052 郑州大学第一附属医院放射科河南郑州450052 郑州大学第一附属医院神经介入科河南郑州450052

目的观察临床-超声列线图预测急性缺血性脑卒中(AIS)短期预后的价值。方法回顾性分析168例接受血管内介入治疗的AIS患者,根据治疗后3个月改良Rankin量表评分将其分为预后良好组(n=134)及预后不良组(n=34)。比较组间临床及超声资料,采用... 详细信息

目的观察临床-超声列线图预测急性缺血性脑卒中(AIS)短期预后的价值。方法回顾性分析168例接受血管内介入治疗的AIS患者,根据治疗后3个月改良Rankin量表评分将其分为预后良好组(n=134)及预后不良组(n=34)。比较组间临床及超声资料,采用最小绝对收缩和选择算子(LASSO)算法及Cox回归方程分析AIS短期预后的独立影响因素,以之分别构建临床、超声及临床-超声列线图模型;绘制受试者工作特征曲线,计算曲线下面积(AUC),评估各模型预测AIS短期预后的效能。结果发病至入院时间、美国国立卫生院卒中量表(NIHSS)评分、Alberta卒中项目早期CT评分(ASPECTS)、斑块时间-强度曲线强度均值(TIC-M)及峰值强度(TIC-P)和伽马拟合曲线的AUC均为AIS短期预后的独立影响因素(P均<0.05)。临床、超声及临床-超声列线图模型预测AIS短期预后的AUC分别为0.888、0.758及0.921,以临床-超声列线图模型的预测效能最高(P均<0.05)。结论临床-超声列线图可有效预测AIS短期预后。

关键词：脑卒中超声检查预后

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Biomaterials and emerging technologies for tissue engineering and in vitro models

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Bio-Design and Manufacturing 2024年第3期7卷 237-239页

作者： j.Miguel Oliveira Rui L.Reis 3B’s Research Group I3Bs-Research Institute on BiomaterialsBiodegradables and BiomimeticsHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineUniversity of MinhoAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVS/3B’s-PT Government Associate Laboratory 4806-909 Braga/GuimarãesPortugal

The latest advances in the field of biomaterials have opened new avenues for scientific breakthroughs in tissue engineer-ing which greatly contributed for the successful translation of tissue engineering products into the market/***-materials are easily processed to become similar to natural extracellular matrix,making them ideal temporary supports for mimicking the three-dimensional(3D)microenvironment required for maintaining the adequate cell/tissue functions both in vitro and in vivo^([1]).

关键词： breakthrough biomaterials engineer

Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by crystal plasticity finite element method

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journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： Y.B.Zhang S.j.Song F.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analytical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension crystal plasticity finite element(3D CPFE)simulations,co-deformation and instability of hetero-phase interface in different material systems were herein studied for polycrystalline metal matrix composites(MMCs).Local stress and strain fields in two types of 3layer MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability can be observed in the fcc/bcc systems than in the fcc/fcc systems upon refining to metallic nanolayered composites(MNCs).By detailed analysis of stress and strain localization,it has been demonstrated that the interface instability is always accompanied by high-stress concentration,i.e.,thermodynamic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermodynamic driving forceG and the kinetic energy barrier Q during dislocation and shear banding can be adopted to classify the deformation modes,following the so-called thermo-kinetic *** by inserting a high density of high-energy interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by a couple of thermodynamics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially designing MNCs.

关键词： Thermodynamics and kinetics Physics-based constitutive modeling Hetero-phase interface Crystal plasticity finite element

冷氢化换热器泄漏问题与对策研究——以冷氢化三、四级换热器泄漏问题为例

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石化技术 2024年第5期31卷 150-152页

作者：杜大将井瑛内蒙古新特硅材料有限公司内蒙古包头014100

装置运行期间,冷氢化换热器的质量和稳定性直接影响运行效果。一旦冷氢化换热器出现泄漏问题,将影响装置的能耗和转化率。基于此,分析了冷氢化换热器常见的泄漏问题,以某公司冷氢化三、四级换热器为主要研究对象,并分析了换热器泄漏的... 详细信息

装置运行期间,冷氢化换热器的质量和稳定性直接影响运行效果。一旦冷氢化换热器出现泄漏问题,将影响装置的能耗和转化率。基于此,分析了冷氢化换热器常见的泄漏问题,以某公司冷氢化三、四级换热器为主要研究对象,并分析了换热器泄漏的主要情况和具体原因,并以此为基础,探究了对应的冷氢化换热器泄漏预防和处理对策,希望能够对相关工作提供一定帮助。

关键词：冷氢化换热器泄漏问题处理对策

A facile strategy for tuning the density of surface-grafted biomolecules for melt extrusion-based additive manufacturing applications

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Bio-Design and Manufacturing 2024年第3期7卷 277-291页

作者： I.A.O.Beeren G.Dos Santos P.j.Dijkstra C.Mota j.Bauer H.Ferreira Rui L.Reis N.Neves S.Camarero-Espinosa M.B.Baker L.Moroni Department of Complex Tissue Regeneration MERLN Institute for Technology-Inspired Regenerative MedicineMaastricht University6229 ER MaastrichtThe Netherlands 3B’s Research Group I3Bs–Research Institute on BiomaterialsBiodegradables and BiomimeticsHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineUniversity of MinhoAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVS/3B’s-PT Government Associate Laboratory 4806-909 Braga/GuimarãesPortugal POLYMAT University of the Basque Country UPV/EHU20018 Donostia/San SebastiánSpain IKERBASQUE Basque Foundation for Science48009 BilbaoSpain

Melt extrusion-based additive manufacturing(ME-AM)is a promising technique to fabricate porous scaffolds for tissue engi-neering ***,most synthetic semicrystalline polymers do not possess the intrinsic biological activity required to control cell *** of biomolecules on polymeric surfaces of AM scaffolds enhances the bioactivity of a construct;however,there are limited strategies available to control the surface ***,we report a strategy to tune the surface density of bioactive groups by blending a low molecular weight poly(ε-caprolactone)5k(PCL5k)containing orthogonally reactive azide groups with an unfunctionalized high molecular weight PCL75k at different *** porous three-dimensional(3D)scaf-folds were then fabricated using a high weight percentage(75 wt.%)of the low molecular weight PCL *** a proof-of-concept test,we prepared films of three different mass ratios of low and high molecular weight polymers with a thermopress and reacted with an alkynated fluorescent model compound on the surface,yielding a density of 201-561 pmol/cm^(2).Subsequently,a bone morphogenetic protein 2(BMP-2)-derived peptide was grafted onto the films comprising different blend compositions,and the effect of peptide surface density on the osteogenic differentiation of human mesenchymal stromal cells(hMSCs)was *** two weeks of culturing in a basic medium,cells expressed higher levels of BMP receptor II(BMPRII)on films with the conjugated *** addition,we found that alkaline phosphatase activity was only significantly enhanced on films contain-ing the highest peptide density(i.e.,561 pmol/cm^(2)),indicating the importance of the surface *** together,these results emphasize that the density of surface peptides on cell differentiation must be considered at the cell-material ***,we have presented a viable strategy for ME-AM community that desires to tune the bulk and surface functionality via blending of(m

关键词： Additive manufacturing Blending Surface functionalization Surface density Click chemistry Human

无创左室压力-应变环技术评估不同心率甲亢患者左室心肌功能

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武汉大学学报（医学版） 2024年第7期45卷 825-830,855页

作者：王末凤甘玲张加琪尹家保锦州医科大学湖北医药学院附属襄阳市第一人民医院研究生联合培养基地超声影像科湖北襄阳441000 湖北医药学院附属襄阳市第一人民医院超声影像科湖北襄阳441000

目的:研究无创左室压力-应变环(LV-PSL)技术评估不同心率甲亢患者心肌功能的临床应用价值。方法:根据纳入及排除标准在湖北医药学院附属襄阳市第一人民医院收集71名初次确诊且未经治疗的甲亢患者。依据是否心动过速分为A组[心率(HR)100... 详细信息

目的:研究无创左室压力-应变环(LV-PSL)技术评估不同心率甲亢患者心肌功能的临床应用价值。方法:根据纳入及排除标准在湖北医药学院附属襄阳市第一人民医院收集71名初次确诊且未经治疗的甲亢患者。依据是否心动过速分为A组[心率(HR)100次/min,n=33),对照组纳入健康志愿者(n=50)。比较各组参数的差异;探讨HR与心肌做功参数[整体做功指数(GWI)、整体有用功(GCW)、整体无用功(GWW)、整体做功效率(GWE)]的相关性。绘制受试者工作特征(ROC)曲线,分析左室整体纵向应变(GLS)与心肌做功参数评估甲亢患者左室心肌功能的效能。结果:相较于对照组,A组和B组的收缩压(SBP)、HR、游离三碘甲状腺原氨酸(FT3)、游离甲状腺素(FT4)、病程、主动脉舒张末期内径(AOEDD)、GWW均增高,而促甲状腺素(TSH)、GLS、GWI、GCW、GWE均降低,差异具有统计学意义(P<0.05)。相较于A组,B组的SBP、HR、FT3、FT4、病程、GWW增高,而GWE降低,差异具有统计学意义(P<0.05)。相关性分析显示,HR与GLS、GWI、GCW、GWE呈负相关,与GWW呈正相关。GLS、GWI、GCW、GWW及GWE评估甲亢患者左室功能的曲线下面积分别为:0.754、0.795、0.728、0.836及0.850。其中,GWW与GWE评估效能较高。结论:无创LV-PSL技术可早期定量评估不同心率甲亢患者左心室功能,可为临床早期预警、早期干预提供参考价值。

关键词：甲亢左室压力-应变环心率心肌功能

Benign liver tumors in pediatric patients-Review with emphasis on imaging features

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World journal of Gastroenterology 2015年第28期21卷 8541-8561页

作者： Liliana Chiorean Xin-Wu Cui Andrea Tannapfel Doris Franke Martin stenzel Wojciech Kosiak Dagmar Schreiber-Dietrich j?rg jüngert jian-Min Chang Christoph F Dietrich Sino-German Research Center of Ultrasound in Medicine the First Affiliated Hospital of Zhengzhou University Medical Department 2 Caritas-Krankenhaus Institut für Pathologie Ruhruniversit?t Bochum Georgius Agricola Stiftung Ruhr Department of Paediatric Kidney Liver and Metabolic Diseases Children's Hospital Hannover Medical School Department of Pediatric Radiology University of Freiburg Department of Pediatric Hematology and Oncology Medical University of Gdansk Department of Pediatrics University of Erlangen

Benign hepatic tumors are commonly observed in adults,but rarely reported in *** reasons for this remain speculative and the exact data concerning the incidence of these lesions are *** hepatic tumors represent a diverse group of epithelial and mesenchymal *** pediatric patients,most benign focal liver lesions are inborn and may grow like the rest of the *** of pediatric liver diseases and their imaging appearances is essential in order to make an appropriate differential *** of the appropriate imaging test is challenging,since it depends on a number of age-related *** paper will discuss the most frequently encountered benign liver tumors in children(infantile hepatic hemangioendothelioma,mesenchymal hamartoma,focal nodular hyperplasia,nodular regenerative hyperplasia,and hepatocellular adenoma),as well as a comparison to the current knowledge regarding such tumors in adult *** current emphasis is on imaging features,which are helpful not only for the initial diagnosis,but also for pre- and posttreatment evaluation and *** addition,future perspectives of contrast-enhanced ultrasound(CEUS) in pediatric patients are highlighted,with descriptions of enhancement patterns for each lesion being *** role of advanced imaging tests such as CEUS and magnetic resonance imaging,which allow for non-invasive assessment of liver tumors,is of utmost importance in pediatric patients,especially when repeated imaging tests are needed and radiation exposure should be avoided.

关键词： Focal liver lesions Benign Pediatric Children Ultrasound

基于CT细胞外间隙容积分数预测粗梁-团块型肝细胞癌

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中国介入影像与治疗学 2024年第7期21卷 431-435页

作者：杭嘉乐王文剑杨鑫田秀春傅剑雄孙骏叶靖罗先富苏北人民医院扬州大学附属苏北人民医院医学影像科江苏扬州225001 苏北人民医院扬州大学附属苏北人民医院病理科江苏扬州225001

目的探讨基于CT细胞外间隙容积分数(ECV)预测粗梁-团块型肝细胞癌(MTM-HCC)的价值。方法回顾性分析23例MTM-HCC(MTM-HCC组)和56例非MTM-HCC(n MTM-HCC组)患者资料,比较组间CT表现差异;基于平扫(P)及增强平衡期(E)CT测量腹主动脉(P-CT腹... 详细信息

目的探讨基于CT细胞外间隙容积分数(ECV)预测粗梁-团块型肝细胞癌(MTM-HCC)的价值。方法回顾性分析23例MTM-HCC(MTM-HCC组)和56例非MTM-HCC(n MTM-HCC组)患者资料,比较组间CT表现差异;基于平扫(P)及增强平衡期(E)CT测量腹主动脉(P-CT腹主动脉、E-CT腹主动脉)、肿瘤(P-CT肿瘤、E-CT肿瘤)及非瘤肝实质(P-CT肝实质、E-CT肝实质)CT值,计算肿瘤及肝实质ECV,对比组间ECV相关参数。绘制受试者工作曲线,计算曲线下面积(AUC),评估ECV相关参数用于预测MTM-HCC的效能。结果组间CT表现差异均无统计学意义(P均>0.05)。MTM-HCC组E-CT肿瘤、Δ肿瘤(肿瘤区域绝对强化CT值)及ECV肿瘤均低于n MTM-HCC组(P均<0.01)。以E-CT肿瘤、Δ肿瘤及ECV肿瘤预测MTM-HCC的AUC分别0.74、0.77、0.87,ECV肿瘤的AUC高于E-CT肿瘤和Δ肿瘤(Z=2.271、2.557,P=0.023、0.011)。结论基于CT ECV可有效预测MTM-HCC。

关键词：癌,肝细胞体层摄影术 X线计算机细胞外间隙容积分数