基于近地面高光谱影像的冬小麦日光诱导叶绿素荧光提取与分析

结合FluorMOD模型模拟数据与利用光谱分辨率3.3 nm、光谱采样间隔为0.71~0.74 nm近地面成像高光谱系统获取的抽穗期小麦高光谱影像比较3种基于夫琅和费线暗线的提取方法(FLD,3FLD和iFLD)的精确性和稳定性。结果表明当光谱分辨率为3.3 nm时,在760 nm附近的O₂-A波段可以有效提取日光诱导叶绿素荧光,而在687 nm附近的O₂-B波段不适合。当存在噪声时,FLD和3FLD的稳定性高于iFLD,FLD倾向于高估荧光值。     

武器装备维修性验证试验方法研究

近年来,我军开始推行武器装备三级维修保障体系向两级维修保障体系转变的维修体制改革。武器装备的维修性是实施装备两级维修保障体制改革的关键,在生产定型阶段对其进行维修性验证试验很有必要。为了进一步完善维修性验证试验方法,以适应维修体制改革的需求,分别对开展武器装备维修性验证试验工作的时机、内容、方法与流程进行了概述;在分析了当前维修性验证试验方法特点的基础上,重点对维修性验证试验工作中的试验方法的选取、样本量确定及样本分配、故障模拟及注入三个关键技术及研究现状进行了总结与归纳;通过对试验关键技术的研究,分析了当前开展维修性验证试验工作存在的问题,对进一步开展维修性验证试验方法研究的内容及方向进行了展望。     

基于拜占庭故障模式的空天飞行器GNC系统架构研究

针对空天飞行器对GNC系统的高可靠性需求,开展了基于拜占庭故障模式的GNC系统架构研究,采用四机三总线架构设计方案,通过系统内总线实现输入数据及输出数据多机冗余比对,防止拜占庭故障的发生,提升了系统可靠性,实现了系统自检测和故障的准确定位及隔离,并具有在线故障诊断、故障自修复功能,同时解决了高动态、强干扰环境下系统自主性较差的问题,提升了GNC系统可靠性和容错性;经分析,该系统架构能够满足空天飞行器在轨、再入复杂任务需求。     

A numerical analysis of gain characteristics of Er-doped Al2O3 waveguide amplifiers

The gain characteristics of erbium-doped Al₂O₃ waveguide amplifiers are investigated by solving numerically rate equations with upconversion effects and propagation equations. We obtained the dependence of gain of erbium-doped Al₂O₃ waveguide amplifiers on the waveguide length, erbium concentration and pump power at different pumping wavelengths (980 and 1480 nm). The performance of amplifiers pumping at 1480 and 980 nm are compared. It is shown that 980 nm pumping has higher gain and higher pumping efficiency. The parameters of waveguide amplifiers have been optimized. A optical gain of 43 dB can be achieved for a optimum waveguide length of 8.25 cm and 5.8 × 10²⁰ cm^–3 Er concentration pumped with 100 mW at 980 nm, that is a gain of 5.2 dB/cm.     

Study on the Spectrum of Miniature Optically Pumped NH3 Submillimeter-Wave Laser

By means of an iteration method and taking into account the broadening of the infrared pumping laser, the spectrum of a miniature, optically pumped, superradiant NH₃ submillimeter-wave(SMMW) gas laser pumped by CO₂-10R(8) has been calculated and studied by solving density matrix equations. Experimentally, the interferogram of miniature SMMW laser pumped by a TEA-CO₂ laser with 10R(8) line is measured. This is the first time that the theoretical spectrum has been in good agreement with experimental results.     

连续灰度铁电液晶器件制备

采用N*-Sc*序列相铁电液晶,通过控制在N*-Sc*相变时施加电压的频率和幅值,制备了不同分子层排列结构的器件,获得了“V”字形和半“V”字形的电光特性曲线,从而可以实现连续灰度.根据铁电液晶自发偶极矩与电场力矩的相互作用原理,分析了器件形成不同分子层排列结构及呈现“V”字形和半“V”字形电光特性的原因.     

Crystallization Kinetics of Co48Cr15Mo14C15BaEr2 Bulk Metallic Glass with High Thermal Stability

We investigate the crystallization kinetics of Co48Cr15Mo14C15B6Er2 bulk metallic glass. It is found that Co48Cr15Mo14C15B6Er2 alloy shows extraordinary glass-forming ability, and a fully glassy rod with a diameter of 10mm can be formed, Thermal analysis exhibits that this glassy alloy has a high thermal stability, Johnson-Mehl-Avrami analysis of isothermal differential scanning calorimetry demonstrates that the crystalline phases homogeneously nucleates at a constant rate and grows linearly at a constant rate in three dimensions in the supercooled liquid of the glassy alloy.     

微孔板结合化学发光法快速测定覆盆子中总糖蛋白的抗氧化活性

在碱性条件下,覆盆子总糖蛋白对鲁米诺-过氢化氢、鲁米诺-邻苯三酚-氢氧化钠和鲁米诺-硫酸铜-过氧化氢化学发光体系具有明显的抑制作用。基于这一特点,本文将微孔板与化学发光法结合,在优化条件下,建立了覆盆子总糖蛋白清除H2O2、O2-和.OH自由基能力的快速检测方法,结果表明该方法具有样品用量少、操作简单、检测速度快等优点,适用于药物中有效成分的活性检测及筛选。     

Laser spectroscopy of VS: hyperfine and rotational structure of the CΣ-XΣ transition

The (0,0) and (0,1) bands of the C⁴Σ⁻-X⁴Σ⁻ electronic transition of VS (near 809 and 846 nm, respectively) have been recorded at high resolution by laser-induced fluorescence, following the reaction of laser-ablated vanadium atoms with CS₂ under supersonic free-jet conditions. A least squares fit to the resolved hyperfine components of the rotational lines gives the rotational constants and bond lengths as C⁴Σ⁻: , ; X⁴Σ⁻: , . The electron spin parameters for the two states show that there are some similarities between the states of VS and those of VO, but the hyperfine parameters show that the compositions of the partly filled molecular orbitals are by no means the same. The ground state Fermi contact parameter of VS, b(X⁴Σ⁻), is only 58% of that of the ground state of VO, which implies that the σ orbital of the ground σδ² electron configuration has less than 50% vanadium 4s character. Similarly, the excited state Fermi contact parameter, b(C⁴Σ⁻), is very much smaller than that of VO. No local rotational perturbations have been found in the C⁴Σ⁻ state of VS, though an internal hyperfine perturbation between the F₂ and F₃ electron components at low N confuses the hyperfine structure and induces some forbidden (ΔJ=±2) rotational branches.     

Spectra of optically pumped superradiant and cavity NH3 far-infrared laser

Based on the density matrix theory of quantum system, the spectra of optically pumped superradiant and cavity NH₃ far-infrared (FIR) lasers were calculated by means of iteration method. The calculation showed that, compared with the optically pumped superradiant FIR laser, the cavity laser had a wider band spectrum of FIR emission and a higher output power under certain condition, moreover, the spectra of cavity laser had multi longitudinal-mode structure. Supported by the Research Foundation of Hubei Province Education Committee, PRC