TFM调制及其改进技术的研究

通过对TFM调制技术的研究,修正了其中预调制滤波器冲击响应波形g(f)在时间轴上的位置及其频谱G(w)的表达式.然后将TFM基带信号进行近似,即对TFM的相位路径进行进一步的控制,得到一个改进的TFM调制技术.改进后的TFM调制技术和原TFM调制技术相比,频带压缩能力提高了一倍,误码性能不变,但会出现3 dB的寄生调幅,需要提高发射机的发射功率.     

爆轰试验用新型射频连接器的结构设计

针对目前爆轰试验中使用的机械密封射频连接器存在的问题.设计了基于玻璃封接技术的新型密封射频连接器结构,并进行了射频反射补偿计算和强度分析.本项研究为爆轰条件下新型密封射频连接器的研制提供了设计依据.     

高精度快速可控光纤真延迟线实验研究

在相控阵雷达中使用光纤实时延迟技术,可实现大角度瞬时宽带扫描.利用半导体光放大器和法拉第旋转镜实现了快速切换的延迟线,此技术具有切换速度快,延迟精度高,输出功率恒定,偏振不相关等优点.实验结果表明,此结构能够实现1 ps的延时精度,误差不超过0.1 ps.     

2，4-二氯苯乙酮合成工艺的研究

以间-二氯苯为原料,乙酸酐为酰化试剂,合成2,4-二氯苯乙酮.考察影响酰化反应的主要因素,结果表明最适宜的反应条件是:间-二氯苯:乙酸酐的摩尔比为2:1,缓慢滴加乙酸酐时温度保持在50℃左右(低于60℃),然后回流反应温度上升至90～95℃,搅拌并保持约2.5h,最终所得产品收率可达81.8%.     

偏高岭土的研究现状及展望

简要介绍了偏高岭土的反应机理和在国内外的研究现状。同时对偏高岭土的研究进行了展望 ,提出因麦特林水泥原料丰富 ,污染小 ,加工简单 ,性能优越 ,其应用前景广阔 ,应对其加强研究。     

Synthesis and characterization of molybdenum disulphide formed from ammonium tetrathiomolybdate

An investigation has been carried out into the possibility of in situ formation of MoS2 within porous anodic films on aluminium, to improve subsequent tribological behaviour, by re-anodizing in thiomolybdate electrolyte. Acidification of thiomolybdate was employed to simulate the conditions for formation of the sulphide at the anodic film/electrolyte interface, followed by appropriate vacuum heat treatments to study possible temperature effects on the sulphide due to either friction or Joule heating during anodizing. The products of both acidification and heat treatment, characterized by X-ray powder diffraction and scanning electron microscopy, were compared with those formed by direct thermal decomposition of ammonium tetrathiomolybdate crystals. The precipitate formed by acidification was mainly amorphous molybdenum trisulphide (MoS3), which on heat treatment at 450 and 850°C yielded 3R-MoS2. 3R-MoS2 also formed by the thermal decomposition of thiomolybdate crystals. Thermogravimetric and differential thermal analyses showed that the decomposition of MoS3 to MoS2 occurred in the range 220–370°C and revealed the sequence of reaction steps. The findings suggest that mainly amorphous MoS3 is formed as a consequence of changes in the pH of the film/electrolyte interface during re-anodizing but the product is relatively easily transformed to crystalline MoS2 on moderate heating which may occur during wear processes.     

超薄SiO2层的热生长

隧道小孔中超薄ＳｉＯ２的生长是ＥＥＰＲＯＭ电路制造的关键工艺之一。采用ＳＵＰＲＥＭ－Ⅲ工艺模拟程序对超薄ＳｉＯ２的热生长进行了工艺模拟，经过大量的工艺实验及优化，确定了超薄ＳｉＯ２的最佳生长条件，生长出的ＳｉＯ２性能良好，完全可满足ＥＥＰＲＯＭ研制的要求。     

一种改进的共同进化遗传算法及其应用

将共同进化遗传算法应用于临床营养决策优化中,虽然取得了一定成果,但算法中仍存在早熟现象、局部搜索能量弱等问题,为此提出一种改进的共同进化模型。算法使用新的子群体划分方法和交叉算子,引入精英保留策略、信息交换原则和小生境技术。通过对糖尿病营养治疗的仿真表明,改进后的算法在保证群体多样性和避免早熟现象的前提下,提高了算法的局部和全局寻优能力,且膳食配方中营养素达标率符合要求,满足专家建议的糖尿病饮食需求。