温度交变中光纤接触式激光火工品的失效原因及抑制研究

为研究温度冲击、温度循环等温度交变环境对激光火工品发火时间的影响规律及作用机理,采用掺杂炭黑的高氯酸·四氨·双(5-硝基四唑)合钴(BNCP)为始发药剂及光纤窗口结构的激光火工品为实验样机,对经历47 h和94 h温度交变实验后的掺杂BNCP始发药剂性能、激光火工品结构变化、药剂和光纤约束情况进行了研究。结果表明,温度交变前激光火工品发火时间具有小于0.2 ms的高瞬发性,经历47 h温度交变后,发火时间会延迟至0.5 ms以上;随着温度交变时间的增长,达到94 h后个别产品发火延迟时间超过1 ms,甚至出现瞎火情况。掺杂BNCP始发药经历47 h的温度交变环境后出现碎晶,堆积密度从0.43 g·cm^(-3)降低到0.32 g·cm^(-3),但碎晶现象不影响药剂的热分解性能及激光火工品的发火性能。温度交变环境下,火工品壳体结构与药剂膨胀系数的差异导致光纤和药剂间出现点火间隙,点火间隙同时影响激光光斑强度与热点的扩散效应,进而影响发火。通过增强药剂和光纤之间的约束可有效减少温度交变情况下点火间隙的产生,提高激光火工品的环境适应能力。

PHF19在肺腺癌中的表达及对免疫微环境的影响

目的:探讨PHD锌指蛋白19(PHF19)在肺腺癌中的表达水平、临床预后、遗传改变、甲基化值、生物学功能和免疫调节作用。方法:基于癌症基因组图谱(TCGA)数据库肺腺癌的RNA队列数据,通过TIMER数据库、UALCAN数据库分析PHF19在肺腺癌和正常组织之间的表达差异及其表达水平与患者预后之间的关系,cBioPortal数据库、TIMER数据库分析PHF19在肺腺癌中的基因突变情况,UALCAN数据库分析PHF19在肺腺癌中的启动子甲基化水平,LinkedOmics数据库、KEGG数据库进行PHF19共表达基因的富集分析,TIMER数据库探索PHF19在肺腺癌中的表达与免疫浸润水平的相关性。结果:PHF19在肺腺癌组织中的表达上调,其高表达与肺腺癌患者的临床病理分期、淋巴结转移和总生存期缩短显著相关,0.9%的患者出现遗传变异,扩增和错义突变是最常见的突变,TP53突变可导致PHF19高表达,PHF19的启动子甲基化水平在肺腺癌中显著降低,PHF19的功能集中于细胞有丝分裂过程和细胞周期,PHF19表达水平与肿瘤免疫细胞浸润和免疫检查点表达呈显著相关。结论:PHF19可作为肺腺癌预后不良的标志物,并在肺腺癌的发生和发展中起着重要作用。

RDX驱动台阶式飞片的速度试验研究

为提高RDX驱动台阶式飞片的可靠性,基于光子多普勒测速技术(Photonic Doppler Velocimetry,PDV)搭建了激光点火RDX驱动台阶式钛合金飞片的速度测试系统,试验研究了RDX装药量、飞片剪切厚度及飞片厚度对飞片速度的影响。结果表明:当装药量从40 mg增加至85 mg,飞片峰值速度由494.46 m·s^(-1)线性增加至591.86 m·s^(-1);当飞片剪切厚度从0.2 mm增加至0.8 mm,飞片峰值速度由508.98 m·s^(-1)线性增加至557.53 m·s^(-1);当飞片厚度从1.0 mm增加至2.5 mm,飞片峰值速度由561.32 m·s^(-1)指数衰减至397.34 m·s^(-1),同时飞片动能由1.347J线性增加至1.688 J。因此,通过增加RDX装药量、飞片剪切厚度或飞片厚度可以提高RDX驱动飞片冲击起爆的可靠性。

Expression of PHF19 in lung adenocarcinoma and its effect on immune microenvironment

Objective:To investigate the expression level,clinical prognosis,genetic changes,methylation value,biological function and immunomodulatory effects of PHF19 in lung adenocarcinoma.Methods:Based on the RNA cohort data of lung adenocarcinoma in the Cancer Genome Atlas(TCGA)database,the expression difference of PHF19 between lung adenocarcinoma and normal tissues and the relationship between the expression level and the prognosis of patients were analyzed by using TIMER database and UALCAN database.The gene mutation of PHF19 in lung adenocarcinoma was analyzed in cBioPortal database and TIMER database.The promoter methylation level of PHF19 in lung adenocarcinoma was analyzed in UALCAN database.The enrichment of PHF19 co-expression gene was analyzed in LinkedOmics database and KEGG database.The correlation between the expression of PHF19 in lung adenocarcinoma and the level of immunoinfiltration was explored in the TIMER database.Results:The expression of PHF19 in lung adenocarcinoma tissues was up-regulated,and its high expression was significantly correlated with the pathological stage,lymph node metastasis and shortened overall survival of lung adenocarcinoma patients.Genetic variation was found in 0.9%of patients,amplification and missense mutation were the most common mutations,and TP53 mutation could lead to the high expression of PHF19.The promoter methylation level of PHF19 significantly decreased in lung adenocarcinoma.The function of PHF19 was focused on the process of cell mitosis and cell cycle.The expression level of PHF19 was significantly correlated with tumor immune cell infiltration and immune checkpoint expression.Conclusion:PHF19 can be used as a marker of poor prognosis of lung adenocarcinoma and plays an important role in the occurrence and development of lung adenocarcinoma.