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New 4-imino-4H-Chromeno[2,3-d]Pyrimidin-3(5H)-Amine: Synthesis, Cytotoxic Effects on Tumoral Cell Lines and in Silico ADMET Properties
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作者 Marwa Dhiabi Sirine Karoui +7 位作者 Mehdi Fakhfakh Souhir Abid Emmanuelle Limanton Rémy Le Guével Thierry Charlier Ludovic Paquin Jean-Pierre Bazureau Houcine Ammar 《International Journal of Organic Chemistry》 2024年第3期107-122,共16页
The synthesis of new 4-imino-4H-chromeno[2,3-d]pyrimidin-3(5H)-amine in four steps including one step under microwave dielectric heating is reported. The structural identity of the synthesized compounds was establishe... The synthesis of new 4-imino-4H-chromeno[2,3-d]pyrimidin-3(5H)-amine in four steps including one step under microwave dielectric heating is reported. The structural identity of the synthesized compounds was established according to their spectroscopic analysis, such as FT-IR, NMR and mass spectroscopy. These new compounds were tested for their antiproliferative activities on seven representative human tumoral cell lines (Huh7 D12, Caco2, MDA-MB231, MDA-MB468, HCT116, PC3 and MCF7) and also on fibroblasts. Among them, only the compounds 6c showed micromolar cytotoxic activity on tumor cell lines (1.8 50 50 > 25 μM). Finally, in silico ADMET studies ware performed to investigate the possibility of using of the identified compound 6c as potential anti-tumor compound. 展开更多
关键词 2-Amino-4H-Chromene 4H-Chromeno[2 3-d]Pyrimidin-3(5H)-Amine Microwave Irradiation Tumoral Cell line in Silico ADMET
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SiO_(2)中间层反应连接LaCrO_(3)陶瓷的机理及界面应力模拟研究
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作者 赵敏 郭洪飞 +1 位作者 侯小虎 邬佳芳 《材料导报》 EI CAS CSCD 北大核心 2024年第17期96-103,共8页
合适的连接技术是提高LaCrO_(3)陶瓷加工性能的有效方法。本工作提出以低成本SiO_(2)粉末为中间层、利用放电等离子技术连接LaCrO_(3)的工艺,研究了LaCrO_(3)连接件的连接机理、显微形貌、力学性能等,并利用有限元模拟分析连接件界面应... 合适的连接技术是提高LaCrO_(3)陶瓷加工性能的有效方法。本工作提出以低成本SiO_(2)粉末为中间层、利用放电等离子技术连接LaCrO_(3)的工艺,研究了LaCrO_(3)连接件的连接机理、显微形貌、力学性能等,并利用有限元模拟分析连接件界面应力分布状态。结果表明:LaCrO_(3)/SiO_(2)混合粉末(物质的量比(0.95~1.55)∶1)在1250~1450℃下复合反应生成Cr掺杂的La_(2)Si_(2)O_(7),SiO_(2)中间层连接LaCrO_(3)陶瓷为反应、扩散连接。在1450℃时,连接件获得最高连接强度(29.3 MPa),SiO_(2)中间层及其母材附近区域产生应力集中。SiO_(2)可以作为辅助制造和修复复杂形状LaCrO_(3)陶瓷的一种有潜力的连接中间层。 展开更多
关键词 LaCrO_(3) La_(2)Si_(2)O_(7) 连接 应力模拟
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基于密度泛函理论的团簇Co_(2)Mo_(2)P_(3)催化性质研究
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作者 吴庭慧 方志刚 +2 位作者 刘立娥 宋静丽 宋嘉 《广西师范大学学报(自然科学版)》 CAS 北大核心 2024年第5期141-149,共9页
基于拓扑学原理和密度泛函理论,本文探究团簇Co_(2)Mo_(2)P_(3)的催化反应作用机理及其活性产生的原因,使用Gaussian09程序,在B3LYP/Lanl2dz水平下,对团簇的初始构型进行全参数优化和运算分析。对Co_(2)Mo_(2)P_(3)中各个原子对其HOMO和... 基于拓扑学原理和密度泛函理论,本文探究团簇Co_(2)Mo_(2)P_(3)的催化反应作用机理及其活性产生的原因,使用Gaussian09程序,在B3LYP/Lanl2dz水平下,对团簇的初始构型进行全参数优化和运算分析。对Co_(2)Mo_(2)P_(3)中各个原子对其HOMO和LUMO轨道的贡献进行研究,得到Co对其前线轨道的贡献率为53.511%、59.013%,Co原子在该团簇中是潜在的活性位点。通过观察态密度图和HOMO-LUMO图,发现Co原子是引起费米能量级两边峰值的主要因素。进一步的能隙差和库普曼斯定理分析显示,构型1(4)和3(4)具有较强的得失电子能力,并且拥有比其他构型更强的催化活性,这些结果为深入理解团簇Co_(2)Mo_(2)P_(3)的催化性能提供了有力支持。本研究的发现为团簇Co_(2)Mo_(2)P_(3)在催化反应中的应用机制和活性产生的原因提供了重要理论依据,为进一步优化催化性能,设计高效催化剂提供了有益参考。 展开更多
关键词 团簇Co_(2)Mo_(2)P_(3) 密度泛函理论 前线轨道 催化性质 态密度 能隙差 库普曼斯定理
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过表达膜定位IL-3的293T细胞外泌体的纯化及体外功能验证
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作者 高璐 蔡孟华 +3 位作者 许依 何维 陈慧 张建民 《基础医学与临床》 CAS 2024年第7期947-953,共7页
目的体外验证过表达膜定位IL-3的293T细胞外泌体的功能,为在阿尔茨海默病模型动物的体内功能验证奠定基础。方法利用本课题组的专利结构,构建能定位于外泌体膜上的重组IL-3慢病毒载体,包装病毒感染293T细胞,筛选稳定表达细胞株。用流式... 目的体外验证过表达膜定位IL-3的293T细胞外泌体的功能,为在阿尔茨海默病模型动物的体内功能验证奠定基础。方法利用本课题组的专利结构,构建能定位于外泌体膜上的重组IL-3慢病毒载体,包装病毒感染293T细胞,筛选稳定表达细胞株。用流式细胞测量术和免疫荧光技术对IL-3的膜定位进行验证;超滤离心纯化IL-3外泌体,透射电镜观察外泌体形态;纳米流式测量术检测外泌体粒径分布及浓度;Western blot检测IL-3及外泌体相关标志蛋白质表达;免疫荧光技术检测其对小胶质细胞系BV-2吞噬Aβ淀粉样蛋白能力的影响。结果经过载体构建、病毒感染、嘌呤霉素筛选和验证,得到稳定过表达膜定位IL-3的293T细胞株;收集纯化外泌体,在透射电镜下可见直径50~100 nm的双层膜囊泡结构;免疫印迹结果显示CD63、ALIX、TSG101等多种外泌体标志蛋白质检测阳性,且与对照相比富含IL-3,提示IL-3外泌体纯化成功;免疫荧光技术检测结果显示IL-3外泌体能在体外促进BV-2细胞对Aβ淀粉样蛋白的吞噬作用。结论过表达膜定位IL-3的基因修饰293T细胞外泌体在体外兼具IL-3和外泌体的作用,能够促进小胶质细胞的吞噬作用,为阿尔茨海默病的临床治疗提供新的思路。 展开更多
关键词 白细胞介素3(IL-3) 外泌体 小鼠脑小胶质细胞系(BV-2) 阿尔茨海默病
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不锈钢冶炼用铁水包Al_(2)O_(3)-SiC-C内衬砖的性能与侵蚀机理 被引量:1
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作者 程艳俏 赵惠忠 +3 位作者 潘料庭 余俊 谈利强 刘丛平 《硅酸盐通报》 CAS 北大核心 2023年第1期329-337,共9页
铁水包内衬材料长期服役于间隔周期较长的高、低温交替环境,极易发生剥落与侵蚀损毁。为了探索影响铁水包内衬材料使用寿命的主要因素,对市面上四种铁水包Al_(2)O_(3)-SiC-C内衬砖的化学成分、物相组成、物理性能和微观结构进行了分析,... 铁水包内衬材料长期服役于间隔周期较长的高、低温交替环境,极易发生剥落与侵蚀损毁。为了探索影响铁水包内衬材料使用寿命的主要因素,对市面上四种铁水包Al_(2)O_(3)-SiC-C内衬砖的化学成分、物相组成、物理性能和微观结构进行了分析,并以高炉渣为侵蚀介质,重点研究了不锈钢冶炼用铁水包Al_(2)O_(3)-SiC-C内衬砖的侵蚀机理。结果表明:铁水包Al_(2)O_(3)-SiC-C内衬砖中Al_(2)O_(3)含量越高,高温下制品的液相量越低,越有利于提高耐火砖的高温力学性能;随着含碳量的增加,铁水包Al_(2)O_(3)-SiC-C内衬砖的抗渣性得到明显改善,但抗氧化性及高温抗折强度呈下降趋势;高炉渣中CaO、MgO向耐火砖中渗透,与耐火砖中的Al_(2)O_(3)、SiO 2发生反应形成高熔点的镁铝尖晶石及低熔点的钙长石等,生成的低熔相会加剧耐火砖的侵蚀。 展开更多
关键词 不锈钢冶炼 铁水包 Al_(2)O_(3)-SiC-C内衬砖 高炉渣 抗渣性 抗氧化性
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Potential roles of EZH2, Bmi-1 and mi R-203 in cell proliferation and invasion in hepatocellular carcinoma cell line Hep3B 被引量:12
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作者 Fang Yang Li-Zhi Lv +1 位作者 Qiu-Cheng Cai Yi Jiang 《World Journal of Gastroenterology》 SCIE CAS 2015年第47期13268-13276,共9页
AIM: To investigate the potential roles of enhancer of zeste homolog2(EZH2), Bmi-1 and mi R-203 in cell proliferation and invasion in hepatocellular carcinoma(HCC) cell line Hep3 B.METHODS: A total of 73 patients who ... AIM: To investigate the potential roles of enhancer of zeste homolog2(EZH2), Bmi-1 and mi R-203 in cell proliferation and invasion in hepatocellular carcinoma(HCC) cell line Hep3 B.METHODS: A total of 73 patients who underwent surgical resection at Fuzong Clinical Medical College of Fujian Medical University were enrolled in this study. Hep3 B cells were cultivated in RPMI 1640 medium supplemented with 10% fetal bovine serum at 37?℃. Vectors that containing c DNA of the EZH2 gene or mi R-203 targeted sh RNA plasmid were constructed, and then transfected into Hep3 B cells. The m RNA expression of mi R-203, EZH2, and Bmi-1 was analyzed using quantitative real-time polymerase chain reaction analysis, and the protein levels of EZH2 and Bmi-1 were detected by Western blot analysis. Effect of EZH2 or mi R-203 on cell proliferation was observed by methyl thiazolyl tetrazolium assay, and cell apoptosis was assessed using flow cytometry. Besides, effect of EZH2 or mi R-203 on tumor cell invasion was detected using Transwell assay.RESULTS: The m RNA levels of EZH2 and Bmi-1 in HCC tissues and in Hep3 B cells were significantly higher compared with those in normal samples(P < 0.01), while mi R-203 level was significantly lower in HCC tissues(P < 0.01). Hep3 B cells transfected with EZH2-sh RNA or mi R-203-sh RNA showed lower expression levels of EZH2 and Bmi-1(P < 0.05). Compared with controls, Hep3 B cells transfected with EZH2-sh RNA had relative slow cell proliferation, indicating that low expression of EZH2 and Bmi-1 and overexpression of mi R-203 could inhibit Hep3 B cell proliferation(P < 0.05). The average apoptosis rate of Hep3 B cells transfected with EZH2-sh RNA vector was about 18.631%, while that of Hep3 B cells transfected with sh RNA vector was about 5.33%, suggesting that EZH2 was down-regulated by transfecting with EZH2-sh RNA, and the down-regulated EZH2 contributed to the cell apoptosis. Low expression of EZH2 and Bmi-1 and overexpression of mi R-203 could reduce Hep3 B cell invasion(P < 0.05).CONCLUSION: Our study suggests that EZH2 and Bmi-1 are up-regulated while mi R-203 is downregulated in Hep3 B cells. Mi R-203 may contribute to the metastasis and enhance apoptosis of HCC cells by regulating EZH2 and Bmi-1. Our study may provide a theoretical basis for metastasis of HCC and targeted therapy of HCC. 展开更多
关键词 EZH2 BMI-1 miR-203 Hepatocellularcarcinoma HEP3B cell line INVASION PROLIFERATION
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一起3/2接线方式敞开式隔离开关发热故障分析 被引量:1
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作者 王来源 雷昌成 《四川电力技术》 2023年第1期90-94,共5页
文中主要针对一起3/2接线方式隔离开关接触不良引起保护装置异常事件,从3/2接线方式等值电路、电流分配、接触电阻增大和线路负载变化所引起接触点温升特性等方面进行分析,并与双母线接线方式中隔离开关接触不良引起温升特性进行对比,得... 文中主要针对一起3/2接线方式隔离开关接触不良引起保护装置异常事件,从3/2接线方式等值电路、电流分配、接触电阻增大和线路负载变化所引起接触点温升特性等方面进行分析,并与双母线接线方式中隔离开关接触不良引起温升特性进行对比,得出3/2接线方式中隔离开关接触不良所引起接触点温升特性与负荷变化、标准回路电阻变化的对应关系和差异。 展开更多
关键词 隔离开关 3/2接线 接触电阻 温升极限
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Application of 2-D and 3-D Geo-electrical Resistivity Tomography and Geotechnical Soil Evaluation for Engineering Site Investigation:A Case Study of Okerenkoko Primary School,Warri-Southwest,Delta State,Nigeria
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作者 U.Stanley Eze M.Edirin Okiotor +3 位作者 J.E.Ighodalo B.Jennifer Owonaro A.Saleh Saleh A.Sikiru Jamiu 《Advances in Geological and Geotechnical Engineering Research》 2023年第2期1-23,共23页
In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastr... In the design of building structures,joint efforts must be decided to resolve the depth of competent layers across the intended site to safeguard the durability of civil engineering structures and to avert the disastrous consequences of structural failure and collapse.In this study,an integrated methodology that employed DC resistivity tomography involving 2-D and 3-D techniques and geotechnical-soil analysis was used to evaluate subsoil conditions for engineering site investigation at Okerenkoko primary school,in the Warri-southwest area of Delta State,to adduce the phenomena responsible for the visible cracks/structural failure observed in the buildings.The results obtained brought to light the geological structure beneath the subsurface,which consists of four geoelectric layers identified as topsoil,dry/lithified upper sandy layer,wet sand(water-saturated)and peat/clay/sandy clayey soil(highly water-saturated).The deeply-seated peat/clay materials(ρ≤20Ωm)were delineated in the study area to the depths of 17.1 m and 19.8 m from 2-D and 3-D tomography respectively.3-D images presented as horizontal depth slices revealed the dominance of very low resistivity materials i.e.peat/clay/sandy clay within the fourth,fifth and sixth layers at depths ranging from 8.68-12.5 m,12.5-16.9 m and 16.9-21.9 m respectively.The dominance of mechanically unstable peat/clay/sandy clay layers beneath the subsurface,which are highly mobile in response to volumetric changes,is responsible for the noticeable cracks/failure detected on structures within the study site.These observations were validated by a geotechnical test of soil samples in the study area.Atterberg’s limits of the samples revealed plasticity indices of zero.Thus,the soil samples within the depth analyzed were representatives of sandy soil that does not possess any plasticity.The methods justifiably provided relevant information on the subsurface geology beneath the study site and should be appropriated as major tools for engineering site assessment/geotechnical projects. 展开更多
关键词 2D and 3D resistivity tomography Engineering site/structure Atterberg limits Orthogonal lines Radar sounding
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3D object reconstruction by point coordinates of 2D line drawings 被引量:1
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作者 HAO Wuqiang DONG Lijun 《Computer Aided Drafting,Design and Manufacturing》 2013年第1期32-35,共4页
It is a research subject in computer vision to 3D reconstruction of an object represented by a single 2D line drawing. Previous works on 3D reconstruction from 2D line drawings focus on objects with lines, plane, view... It is a research subject in computer vision to 3D reconstruction of an object represented by a single 2D line drawing. Previous works on 3D reconstruction from 2D line drawings focus on objects with lines, plane, view, and so on. This paper mainly studies the 3D reconstruction from 2D line drawings. Besides, a new approach is proposed: it is that for the research of the point coordinates of 2D line drawings, so as to achieve the object reconstruction by the reconstruction of point coordinates. The reconstruction process includes: (1) the collection of point coordinates (X,Y) of 2D line drawings; (2) the derivation of mathematical formula about the reconstruction of the point of 2D line drawings, and calculating the corresponding point of the 3D coordinates; (3) the regeneration of 3D graphics with 3D points; (4) analyze error by the proportional of parallel of axonometric projection, in order to prove the accuracy of the method. 展开更多
关键词 2D line drawings point coordinates 3D reconstruction
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Electronic Structure,Irreversibility Line and Magnetoresistance of Cu0.3Bi2Se3 Superconductor
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作者 伊合绵 陈朝宇 +13 位作者 孙璇 谢卓晋 冯娅 梁爱基 彭莹莹 何少龙 赵林 刘国东 董晓莉 张君 陈创天 许祖彦 顾根大 周兴江 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第6期141-145,共5页
Cux Bi2Se3 is a superconductor that is a potential candidate for topological superconductors. We report our laser- based angle-resolved photoemission measurement on the electronic structure of the CuxBi2Se3 supercondu... Cux Bi2Se3 is a superconductor that is a potential candidate for topological superconductors. We report our laser- based angle-resolved photoemission measurement on the electronic structure of the CuxBi2Se3 superconductor, and a detailed magneto-resistance measurement in both normal and superconducting states. We find that the topological surface state of the pristine Bi2Se3 topological insulator remains robust after the Cu-intercalation, while the Dirae cone location moves downward due to electron doping. Detailed measurements on the magnetic field-dependence of the resistance in the superconducting state establishes an irreversibility line and gives a value of the upper critical field at zero temperature of ~4000 Oe for the Cu0.3Bi2Se3 superconductor with a middle point Tc of 1.g K. The relation between the upper critical field He2 and temperature T is different from the usual scaling relation found in cuprates and in other kinds of superconductors. Small positive magneto-resistance is observed in Cuo.3Bi2Se3 superconductors up to room temperature. These observations provide useful information for further study of this possible candidate for topological superconductors. 展开更多
关键词 Electronic Structure Irreversibility line and Magnetoresistance of Cu Bi2Se3 Superconductor
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Pressure-Induced Shifts of R1 and R2 Lines of YAG:Cr3+
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作者 ZHANG Zheng-Jie MA Dong-Ping 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第4期754-760,共7页
By means of improved ligand-field theory, the "pure electronic" pressure-induced shifts (PS's) and the PS's due to electron-phonon interaction (EPI) of R1 line and R2 line of YAG:Cr^3+ have been calculated, ... By means of improved ligand-field theory, the "pure electronic" pressure-induced shifts (PS's) and the PS's due to electron-phonon interaction (EPI) of R1 line and R2 line of YAG:Cr^3+ have been calculated, respectively. The calculated results are in very good agreement with the experimental data. It is demonstrated that the admixture of │t^2 2(^3T1)e^4T2〉 and │t^3 2 ^2E〉 bases in the wavefunction of RI level of YAG:Crs+ and its change with pressure play a key role for the PS of RI line. The behaviors of the "pure electronic" PS of RI line and the PS of RI line due to EPI are different. It is the combined eEect of them that gives rise to the total PS of R1 line, which has satisfactorily explained the experimental results. The systematic analyses and comparisons between the feature of R1-line PS of YAG:Cr^3+ and the ones of three laser crystals (GSGG:Cr^3+, GGG:Cr^3+ and ruby) have been made, and the origin of the difference between them has been revealed. 展开更多
关键词 high-pressure effect electron-phonon interaction R lines admixture of |t223T1)e4T2 and |t322E〉 laser crystals
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3D Reconstruction from 2D Line Drawings only with Visible Vertices and Edges
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作者 WANG Xuan DONG Lijun 《Computer Aided Drafting,Design and Manufacturing》 2014年第1期42-45,共4页
The human vision system can reconstruct a 3D object easily from single 2D line drawings even if the hidden lines of the object are invisible. Now, there are many methods have emulated this ability, but when the hidden... The human vision system can reconstruct a 3D object easily from single 2D line drawings even if the hidden lines of the object are invisible. Now, there are many methods have emulated this ability, but when the hidden lines of the object are invisible, these methods cannot reconstruct a complete 3D object. Therefore, we put forward a new algorithm to settle this hard problem. Our approach consists of two steps: (1) infer the invisible vertices and edges to complete the line drawing, (2) propose a vertex-based optimization method to reconstruct a 3D object. 展开更多
关键词 3D reconstruction 2D line drawings hidden topology
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3/2接线方式自适应线路保护策略设计方案 被引量:5
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作者 刘革明 曲广强 +3 位作者 徐晓春 朱晓彤 孙辉 张立斌 《电力系统自动化》 EI CSCD 北大核心 2012年第22期104-107,共4页
3/2接线方式下配置出线隔离开关的输电线路通常会独立配置线路保护装置和短引线保护装置。当操作出线隔离开关以满足系统运行方式要求时,需要人工投退线路保护和短引线保护功能。分析了该接线方式下传统保护配置方案存在的问题,并提出... 3/2接线方式下配置出线隔离开关的输电线路通常会独立配置线路保护装置和短引线保护装置。当操作出线隔离开关以满足系统运行方式要求时,需要人工投退线路保护和短引线保护功能。分析了该接线方式下传统保护配置方案存在的问题,并提出了一种新型线路保护装置的设计方案。新型线路保护装置集成了线路保护和短引线保护功能,结合出线隔离开关的位置信息,自适应地调整保护策略和保护区域。该方案简化了一、二次设计回路,经济性、可靠性更高。 展开更多
关键词 3 2接线 隔离开关 线路保护 短引线保护 自适应保护
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一种3/2接线死区故障隔离与误切元件快速恢复方法 被引量:8
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作者 杨凡 李伟 +3 位作者 尹项根 李仲青 张哲 郭雅蓉 《电力系统保护与控制》 EI CSCD 北大核心 2016年第20期37-42,共6页
在现有3/2接线方式下,由于保护和互感器的配置并未完全交叉,导致死区的存在。在发生死区故障时,一般由死区故障所在间隔保护以及断路器失灵保护动作相互配合以实现故障的彻底隔离。这种做法会使得断路器的切除范围扩大,甚至会导致正常... 在现有3/2接线方式下,由于保护和互感器的配置并未完全交叉,导致死区的存在。在发生死区故障时,一般由死区故障所在间隔保护以及断路器失灵保护动作相互配合以实现故障的彻底隔离。这种做法会使得断路器的切除范围扩大,甚至会导致正常母线不必要的停运,严重影响系统的安全稳定运行。针对上述问题,分析了在不同保护CT配置方式下的死区故障的特点,提出了一种死区故障隔离与误切元件快速恢复的方法。该方法通过引入断路器的开合状态信息来有效地辨别死区故障和断路器失灵情况,同时利用断路器的重合闸功能,快速恢复切除死区故障时的误切断路器,从而显著提高系统的安全稳定运行水平。 展开更多
关键词 3/2接线 死区故障 失灵保护 重合闸
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计及死区故障的3/2接线变电站的Petri网故障诊断方法 被引量:11
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作者 杨雯 刘元琦 +4 位作者 吴小忠 尹项根 徐彪 郝洵 李旭升 《电力系统保护与控制》 EI CSCD 北大核心 2017年第20期28-37,共10页
现有针对3/2接线系统的故障诊断方法较少考虑死区故障,在基于保护和断路器动作信息进行故障诊断时易造成误判。提出一种计及死区故障的3/2接线变电站的Petri网故障诊断方法,除了系统中母线、线路和变压器等元件,对死区位置也建立其加权... 现有针对3/2接线系统的故障诊断方法较少考虑死区故障,在基于保护和断路器动作信息进行故障诊断时易造成误判。提出一种计及死区故障的3/2接线变电站的Petri网故障诊断方法,除了系统中母线、线路和变压器等元件,对死区位置也建立其加权模糊时序Petri网模型。针对3/2接线系统不同死区位置、不同类型故障的跳闸策略,利用保护动作信息和断路器辅助节点开合状态信息构造死区故障辨识逻辑。通过死区故障的逻辑辨识和保护及断路器的时序约束检查,对诊断模型的结构和参数进行修正。测试系统仿真算例和电网实际故障案例表明,该方法能够在保护和断路器不正确动作和警报信息不完整等复杂状态下识别真实故障元件,提高了诊断的准确度和容错性。 展开更多
关键词 3/2接线 死区故障 加权模糊时序Petri网 时序约束
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浅析500kV系统中3/2接线方式线路重合闸 被引量:17
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作者 路改强 刘敏 《电力系统保护与控制》 EI CSCD 北大核心 2009年第23期141-144,共4页
500kV超高压电力系统为保障供电可靠性,大部分采用3/2接线方式,突出问题是断路器保护与自动重合闸装置的配合。根据3/2接线方式较为灵活的特点,利用3/2接线断路器保护自身原理及重合闸装置重合原则,找出其共同点,并结合500kV变电站的运... 500kV超高压电力系统为保障供电可靠性,大部分采用3/2接线方式,突出问题是断路器保护与自动重合闸装置的配合。根据3/2接线方式较为灵活的特点,利用3/2接线断路器保护自身原理及重合闸装置重合原则,找出其共同点,并结合500kV变电站的运行和工作实际,分析论证线路重合闸有关问题,给出了3/2接线断路器重合闸的保护配合方法,对优化运行操作、提高系统运行稳定性和可靠性提供帮助。 展开更多
关键词 500kV系统 3/2接线 重合闸 保护配合
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电站3/2接线和4/3接线的可靠性比较分析 被引量:5
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作者 董百强 谢开贵 周家启 《重庆大学学报(自然科学版)》 EI CAS CSCD 北大核心 2006年第10期10-15,共6页
电站主接线是电力系统接线的主要部分,其结构不仅决定用户能否获得足够的电能,而且也影响到电站建设和改造的经济性.3/2接线和4/3接线在大型电站中应用广泛.选取3组比较方案,其中第1组为单元接线,其余2组为联合单元接线,每组各包括一种... 电站主接线是电力系统接线的主要部分,其结构不仅决定用户能否获得足够的电能,而且也影响到电站建设和改造的经济性.3/2接线和4/3接线在大型电站中应用广泛.选取3组比较方案,其中第1组为单元接线,其余2组为联合单元接线,每组各包括一种3/2接线和4/3接线方案,并利用电站主接线可靠性综合分析系统,对2种接线的可靠性和经济性进行了综合比较分析.计算结果包括各组方案的充裕性、安全性、经济性指标以及元件可靠性参数的敏感度分析.结果表明3/2接线和4/3接线各有优缺点,但3/2接线的适用性较强;发电机故障率对主接线可靠性的影响最为明显;并且在对主接线方案的设计和抉择过程中,可靠性的定量计算必不可少. 展开更多
关键词 电站电气主接线 3/2接线 4/3接线 可靠性 充裕性 安全性 经济性
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采用3/2接线的变电站故障诊断优化模型 被引量:4
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作者 姜伟 廖志伟 +2 位作者 李文清 黄少先 文福拴 《继电器》 CSCD 北大核心 2008年第4期31-36,共6页
采用3/2接线的变电站系统有着自己特殊的电网结构和保护配置方式,但目前电网故障诊断优化模型在具有应用普遍性的同时,并没有很好的考虑这种特殊的接线方式,也就不能充分满足3/2接线系统对故障诊断的要求。优化诊断模型是通过目标函数... 采用3/2接线的变电站系统有着自己特殊的电网结构和保护配置方式,但目前电网故障诊断优化模型在具有应用普遍性的同时,并没有很好的考虑这种特殊的接线方式,也就不能充分满足3/2接线系统对故障诊断的要求。优化诊断模型是通过目标函数来体现和实现的,基于此,通过对现有模型的深入研究,将3/2接线系统的接线方式及其保护配置方式反映到目标函数中,从而使改进后的目标函数能够满足和适用其对故障诊断的需求。最后,通过一个典型的仿真算例证明了此模型的合理性和正确性。 展开更多
关键词 3/2接线系统 故障诊断 优化模型
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RNA干扰C-erbB-2对肺腺癌细胞calu-3增殖的影响 被引量:8
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作者 任淑华 张伟 +3 位作者 曲平 刘义 王井伟 张林 《癌症》 SCIE CAS CSCD 北大核心 2005年第10期1173-1178,共6页
背景与目的:C-erbB-2基因在人乳腺癌、卵巢癌、肺癌中扩增及过量表达,与肿瘤恶性程度增高、转移能力增强、化疗抵抗密切相关,且与预后不良有关。RNA干扰(RNA interfering,RNAi)是一种新的基因治疗技术,能有效、特异性地抑制细胞内基因... 背景与目的:C-erbB-2基因在人乳腺癌、卵巢癌、肺癌中扩增及过量表达,与肿瘤恶性程度增高、转移能力增强、化疗抵抗密切相关,且与预后不良有关。RNA干扰(RNA interfering,RNAi)是一种新的基因治疗技术,能有效、特异性地抑制细胞内基因表达。本实验研究靶向C-erbB-2基因的siRNA(small interferingRNA)对C-erbB-2过表达的肺腺癌细胞calu-3增殖的影响。方法:化学合成的靶向C-erbB-2基因siRNA在脂质体的介导下转染calu-3细胞,观察转染前后细胞表型的改变;通过逆转录聚合酶链反应(reversetranscription-polymerasechainreaction,RT-PCR)和流式细胞术检测转染前后细胞中C-erbB-2mRNA和蛋白水平的变化,四甲基偶氮唑蓝(MTT)法评价对calu-3细胞增殖的抑制作用,流式细胞术检测细胞周期的变化和细胞凋亡情况。结果:靶向C-erbB-2基因siRNA降低了calu-3细胞中C-erbB-2mRNA和蛋白的表达,转染C-erbB-2siRNA48h后calu-3细胞出现C-erbB-2蛋白表达下调。C-erbB-2蛋白阳性率为(25.04±1.56)%,与未转染对照组、空载体组、非特异性siRNA组比较[(98.24±2.23)%、(95.67±1.98)%和(94.79±0.87)%]有显著性差异(P<0.01)。同时C-erbB-2siRNA对calu细胞增殖有抑制作用,使细胞周期阻滞于G0/G1期[C-erbB-2siRNA组(56.6±3.6)%,未转染对照组(45.5±3.2)%,P<0.01],并能诱导细胞凋亡。结论:化学合成的靶向C-erbB-2基因siRNA能有效抑制C-erbB-2基因在calu-3细胞中的表达,并对calu-3细胞增殖有抑制作用。 展开更多
关键词 肺肿瘤 基因治疗 RNA干扰 C-ERBB-2 SIRNA calu-3细胞
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基于邻域信息的3/2接线按串配置断路器保护方案及实现方法 被引量:7
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作者 陈永昕 尹项根 +3 位作者 张哲 杨凡 曹文斌 习伟 《电力自动化设备》 EI CSCD 北大核心 2019年第12期218-223,共6页
根据超高压系统3/2接线变电站结构特点,提出基于邻域信息的按串配置断路器保护方案及其实现方法,提升近后备保护的选择性、速动性和可靠性。按串配置断路器保护方案包括3种优化策略:消除死区的断路器分合优化策略、中断路器重合闸的自... 根据超高压系统3/2接线变电站结构特点,提出基于邻域信息的按串配置断路器保护方案及其实现方法,提升近后备保护的选择性、速动性和可靠性。按串配置断路器保护方案包括3种优化策略:消除死区的断路器分合优化策略、中断路器重合闸的自适应策略、基于运行方式的在线辨识控制策略。进而从站域保护和就地化保护2个角度提出实现方法,并通过仿真分析验证了可行性和有效性。所提方案利用信息共享技术克服传统断路器保护的缺陷,为提升交直流混联电网安全稳定运行提供新的思路。 展开更多
关键词 3/2接线 断路器保护 邻域信息 站域保护 就地化保护
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