光纤复合低压电缆温度分布影响因素分析

光纤低压复合电缆(OPLC)在短路条件下温度迅速升高,直接影响电力系统安全稳定地运行。材料、结构和工作环境是影响光缆热性能的3个重要因素,根据环境选取合适的组成材料和结构能有效改善光缆的热性能。该文在分析电缆稳定运行状态和短路故障状态温升机理的基础上,运用COMSOL软件建立仿真模型,分别研究了导体和绝缘层材料、结构和风速对OPLC热性能的影响。结果表明,OPLC光单元的位置影响光单元本身的热性能;导体为铜和铝时OPLC的热性能基本一致,绝缘材料分别为聚氯乙烯(PVC)和交联聚乙烯(XLPE)时OPLC的热性能差别很大;风速不仅影响OPLC稳态时的最高温度,还影响OPLC到达稳态所用的时间。     

反对称n-AlGaN层对GaN基双蓝光波长发光二极管性能的影响

采用数值分析方法对在InGaN/GaN混合多量子阱活性层和n-GaN之间引入n-AlGaN层的GaN基双蓝光波长发光二极管进行模拟分析.结果发现,与传统的具有p-AlGaN电子阻挡层的双蓝光波长发光二极管相比,这种反对称n-AlGaN层能有效改善电子和空穴在混合多量子阱活性层中的分布均匀性及减少电子溢出,实现电子空穴在各个量子阱中的平衡辐射,从而减弱了双蓝光波长发光二极管的效率衰减.此外,通过改变Al组分可以提高双蓝光波长发光二极管发射光谱的稳定性:当Al组分为0.16时,双蓝光波长发光二极管的光谱在小电流下比较稳定,而Al组分为0.12时,光谱在大电流下比较稳定.     

A dual-blue light-emitting diode based on strain-compensated InGaN-AlGaN/GaN quantum wells

A strain-compensated InGaN quantum well(QW) active region employing a tensile AlGaN barrier is analyzed.Its spectral stability and efficiency droop for a dual-blue light-emitting diode(LED) are improved compared with those of the conventional InGaN/GaN QW dual-blue LEDs based on a stacking structure of two In0.18Ga0.82N/GaN QWs and two In0.12Ga0.88N/GaN QWs on the same sapphire substrate.It is found that the optimal performance is achieved when the Al composition of the strain-compensated AlGaN layer is 0.12 in blue QW and 0.21 in blue-violet QW.The improvement performance can be attributed to the strain-compensated InGaN-AlGaN/GaN QW,which can provide a better carrier confinement and effectively reduce leakage current.     

CTCF通过抑制p53信号通路促进胆管癌细胞的生长、迁移和侵袭

为了探索CCCTC结合因子(CCCTC-binding factor, CTCF)对人胆管癌细胞的生长、迁移和侵袭能力的影响及其潜在的分子作用机制,利用慢病毒感染法获得稳定过表达或敲低CTCF的胆管癌细胞系,采用蛋白质免疫印迹法(Western blotting, Wb)检测CTCF蛋白表达水平,采用Cell Counting Kit-8(CCK-8)法和克隆形成实验检测细胞生长情况,采用Transwell小室实验检测细胞迁移和侵袭能力,采用GraphPad软件(v6)的Mann-Whitney U检验分析CTCF基因在癌和癌旁组织间的mRNA差异表达.结果显示:过表达CTCF可显著促进HCCC-9810和RBE胆管癌细胞的生长、迁移和侵袭能力;敲低CTCF呈现相反的表型.通过通路富集分析发现:CTCF的表达水平在胆管癌中与p53信号通路活性显著负相关,过表达CTCF可显著下调p53及其靶基因p21的mRNA和蛋白表达水平,而敲低CTCF则显著促进p53和p21的mRNA和蛋白表达水平.综上,本研究揭示CTCF可能通过抑制p53信号通路而促进胆管癌细胞生长、迁移和侵袭而发挥促癌基因的功能.     

Dual-blue light-emitting diode based on strain-compensated InGaN-AlGaN/GaN quantum wells

Strain-compensated InGaN quantum well (QW) active region employing tensile AlGaN barrier is analyzed. Its spectral stability and efficiency droop for dual-blue light-emitting diode (LED) are improved compared with those of the conventional InGaN/GaN QW dual-blue LED based on stacking structure of two In_0.18Ga_0.82N/GaN QWs and two In_0.12Ga_0.88N/GaN QWs on the same sapphire substrate. It is found that the optimal performance is achieved when the Al composition of strain-compensated AlGaN layer is 0.12 in blue QW and 0.21 in blue-violet QW. The improvement performance can be attributed to the strain-compensated InGaN-AlGaN/GaN QW that can provide a better carrier confinement and effectively reduce leakage current.