微空心阴极放电推力器性能研究

微空心阴极放电推力器是一种新颖的电热式微推力器,利用纳卫星提供的1~10 W的功率可提高微推进装置的性能。为了预示该推力器的性能,结合实验中测量的气体温度值和火箭发动机原理,初步计算得出微放电推力器的推力范围为几十至上千μN,以氩气为工质比冲量级为600~1 000 N.s/kg,以氦气为工质比冲量级为3 000 N.s/kg。研究结果表明,微空心阴极放电较小的尺寸结构与强烈并可控的气体加热相结合,可以开发应用在电热式微放电推进中,作为微小卫星,尤其是纳卫星和皮卫星的动力系统。     

离子推力器放电腔数值模拟

 为更好地理解放电腔内等离子体物理机制,对Kaufman型离子推力器放电腔进行了数值研究,其中初始电子采用粒子模拟的方法处理,二次电子和离子采用漂移-扩散流体近似描述。模拟结果与已有实验测量数据进行对比表明：所采用计算方法适用于放电腔内等离子体流动规律的数值研究;模拟得到的稳态下等离子体分布及变化规律与实验测量数据相吻合;磁场的设计对初始电子起到显著的约束作用,有效地提高了其与工质气体的电离碰撞几率;二次电子的精确描述还需在流体方程中耦合磁场效应。     

Experiment of passive ranging for three-sensor array in shallow water and post processing

For improving passive ranging of three-sensor array, a sliding cross-correlation method is adopted to improve the performance of time delay estimation. Compared with the traditional cross-correlation, the sliding cross-correlation＇s ability is evidently increased. An improved formula which is in high precision for near target is employed. An algorithm of kicking out wild value is presented, which is on line, can track the target automatically. The algorithm named ＂round filter＂ can pick out the data in high quality with robustness. A ＂dynamic filter＂ is presented, which is combined with the ＂round filter＂ as the post processor. The experimental result of three-sensor array passive ranging of near field target in shallow water is introduced, which suggests that the post processor is indeed obvious in improving the ranging performance.     

Wavelength conversion of chaotic message through gain modulation by injection-locked Fabry-Perot laser diode

<正>We propose a wavelength conversion scheme for chaotic optical communications(COC) based on a Fabry-Perot (FP) laser diode.The FP laser,as a wavelength converter,is injection-locked at one of longitudinal modes by an external continuous-wave(CW) light.The simulation results demonstrated that the chaos masked signal at wavelengthλ_1,which corresponds to the other longitudinal mode of FP laser,can be converted to the injection-locked mode(wavelengthλ_2) based on cross-gain modulation in a closed-loop COC link.A 1.2-GHz chaos masked sinusoidal signal is successfully decoded with signal-to-noise ratio (SNR) beyond 8 dB in 15-nm wavelength conversion range,and the effects of SNR on the signal frequency and conversion span are also investigated.     

直流电弧等离子体法制备纳米粒子实验装置研究

研制了一种实验室用直流电弧等离子体法制备纳米粒子的实验装置,该装置由纳米粒子生成室、阴极、阳极、真空泵和直流电源等组成。其特点是：结构简单、操作方便、成本低。该实验装置可用于制备金属纳米粒子、合金纳米粒子及金属一陶瓷复合纳米粒子。     

含氧有机物作为锂电池正极材料

有机物作为锂电池正极材料具有理论比容量高、原料丰富、环境友好、体系安全的优点,近年来受到关注。本文综述了含氧有机物正极材料的研究进展,概括了醌类、酸酐和硝基化合物等材料的结构特征、电化学性能以及充放电机理,比较了各种材料的优势与不足,并对比了不同有机物材料的放电电位和比容量,同时对该类材料的研究方向进行了展望。     

冠醚配合物热力学性质的研究(Ⅶ)-碱金属与2,3-苯并-6-甲基-15-冠-5配位反应的量热滴定研究

用自制跟踪绝热式滴定量热计研究了新合成的2,3-苯并-6-甲基-15-冠-5在无水甲醇介质中与碱金属的配位反应。     

冠醚配合物热力学性质的研究(Ⅷ)——若干苯-18-冠-6的甲基衍生物与碱金属配位反应的NMR研究

用NMR谱研究了醚环上具有1-3个甲基的18-冠-6衍生物和一些碱金属离子的配位反应,得到了配合物在溶液中有关构象的信息,籍助于CNDO/2方法计算了在醚碳原子上的电荷密度,并测定了Na⁺配合物的稳定常数。     

HEDP与Fe(Ⅲ)配位化合物的制备和性质研究

制备了K₃[Fe(C₂H₅P₂O₇)₂]·4.5H₂O和K₃[Fe(C₂H₆P₂O₇)₂(OH)₂]·3H₂O两种固体配合物,用化学分析、穆斯堡尔谱、红外光谱、差热热重分析和电导测定等研究了它们的性质,推测了配合物的结构。