非平衡磁控溅射TiAlN薄膜的抗高温氧化行为研究

采用非平衡磁控溅射技术在Q235钢基体上制备了TiAlN薄膜,通过精密电子天平、纳米力学探针、划痕测试仪及扫描电镜等测试分析,研究了薄膜氧化动力学行为、薄膜显微硬度和结合力的变化规律及不同温度下氧化后薄膜表面形貌演变规律,探讨了Ti AlN薄膜的抗高温氧化机制。结果表明,在700℃以上TiAlN薄膜的氧化动力学行为服从抛物线规律。随着氧化温度的升高,薄膜的显微硬度和结合力逐渐下降,当氧化温度升高到800℃时,薄膜具有较高的显微硬度和结合力,分别为19.3 GPa和32.1 N,表现出良好的抗高温氧化性能。当氧化温度升高到900℃时,薄膜表面出现了明显的鼓包和裂纹,此时薄膜发生了严重氧化,薄膜已失去对基体的保护作用。     

Comprehensive Analysis of hsa-miR-654-5p’s Tumor-Suppressing Functions

The pivotal roles of miRNAs in carcinogenesis, metastasis, and prognosis have been demonstrated recently in various cancers. This study intended to investigate the specific roles of hsa-miR-654-5p in lung cancer, which is, in general, rarely discussed. A series of closed-loop bioinformatic functional analyses were integrated with in vitro experimental validation to explore the overall biological functions and pan-cancer regulation pattern of miR-654-5p. We found that miR-654-5p abundance was significantly elevated in LUAD tissues and correlated with patients’ survival. A total of 275 potential targets of miR-654-5p were then identified and the miR-654-5p-RNF8 regulation axis was validated in vitro as a proof of concept. Furthermore, we revealed the tumor-suppressing roles of miR-654-5p and demonstrated that miR-654-5p inhibited the lung cancer cell epithelial-mesenchymal transition (EMT) process, cell proliferation, and migration using target-based, abundance-based, and ssGSEA-based bioinformatic methods and in vitro validation. Following the construction of a protein–protein interaction network, 11 highly interconnected hub genes were identified and a five-genes risk scoring model was developed to assess their potential prognostic ability. Our study does not only provide a basic miRNA-mRNA-phenotypes reference map for understanding the function of miR-654-5p in different cancers but also reveals the tumor-suppressing roles and prognostic values of miR-654-5p.     

摩擦改进剂对改善燃油经济性的影响研究

采用四球机试验,考察了钼胺化合物、二烷基二硫代氨基甲酸钼、无灰型摩擦改进剂与摩擦因数的关系以及它们之间的复配作用。结果表明：摩擦改进剂（FM）降低摩擦因数的效果与其化学结构有关;加入量提高,摩擦因数的改善效果明显;不同化学结构的摩擦改进剂复配使用,可以减低整个温度区的摩擦因数。     

我国不锈钢焊接工艺研究现状及进展

随着我国不锈钢消费量的快速增长,不锈钢的焊接技术越来越重要,它直接影响着不锈钢的使用质量和应用领域的拓宽。本文总结了我国不镑钢焊接工艺的研究现状和发展趋势。     

1 000 MW超超临界锅炉分离器制造难点解析

介绍了超超临界锅炉中分离器的主要特点及制造难点,对非向心孔的加工,非向心管接头坡口的加及其装焊等问题,分别进行了论述。     

冷渣器弯管裂纹分析

本文通过对冷渣器中u形管的化学,力学及装配过程等方面的分析,得出在装配U形管过程中,不适当的操作,材料的抗拉强度以及冷作硬化现象是u形管产生裂纹的原因。     

用于星上图像压缩的JPEG2000算法的改进

本文修改了 JPEG2000 算法,通过改变编码顺序节约了大量的计算,提高了运行速度.用此算法对空间太阳望远镜的目标图像进行了实验,结果表明在相同压缩比的情况下,修改后的算法对图像质量没有明显的影响,在运行时间和压缩质量方面都能够满足空间太阳望远镜的压缩任务要求.