腺病毒(adenovirus)DNA的转录活性与宿主细胞核骨架(nuclear matrix)的关系

本文用温和的选择性细胞抽提技术,提取腺病毒(adenovirus)感染6h的Hela细胞核内各种DNA组分,分别以腺病毒DNA的早期转录区(El_a,El_b)与晚期转录区(L_2)作探针进行Southern杂交,结果表明只有正在活跃转录着的腺病毒DNA片段才与宿主细胞核骨架紧密结合,从而说明宿主细胞核骨架可能对病毒DNA的转录有重要作用。     

上游边界层对向上散热的水平热板自然对流换热影响的研究

论文对具有上游边界层场合的水平加热表面向上对流换热的自然对流进行了实验研究,采用全息干涉法测定温度场,对侧壁高度为50,100,150毫米三种情况进行了实验测定,发现其边缘效应与无侧壁时的水平板情况不同,在6×10~3相似文献   

The effect of silica morphology on properties of PVA/silica nano-composites

Two kinds of poly(vinyl alcohol)(PVA)-silica composites were prepared with different methods. One composite was prepared by directly mixing PVA with 80 nm silica nano-particles which were made from tetraethoxysilane(TEOS). The another was obtained by the mixing PVA and hydrolyzed TEOS in the presence of acid-catalyst. The properties of the two PVA/silica hybrids were characterized by means of scanning electron microscopy(SEM), UV-Visible spectroscopy,solubility tests, limiting oxygen index(LOI) test, tensile test and dynamical mechanical analysis(DMA), respectively. The results indicate that PVA-TEOS composites(PT for short) display more transparency than PVA-silica nano-particles hybrids(PS for short). At the same time, The PT composites presented more excellent performance than PS in water resistance, fire resistance and mechanical properties. Moreover, the Tg of PT increased with increasing TEOS content, while that of PS decreased.