基于RCS观测序列的空间目标识别算法

针对低分辨率雷达体制下的空间目标识别问题,提出了基于RCS观测序列的空间目标识别算法.该算法首先对空间目标的低分辨雷达RCS观测序列进行离散小波变换,然后在时间-尺度平面上提取十个有效的统计特征,最后基于模糊分类来识别空间目标.应用四类空间目标的实测数据进行了仿真实验,取得了比较好的识别效果.     

航天光学遥感器光学装调技术现状与展望

航天光学遥感器工作于太空中,长期恶劣的空间环境及短暂发射入轨时的状态对光学系统的设计与装调提出了苛刻的要求,确保光学系统在轨像质优异是航天光学遥感器研制的关键技术.文章结合国际上航天光学遥感器的发展需求对光学系统装调技术及发展现状进行了分析、总结,提出了中国后续航天光学遥感器装调与测试技术的突破方向.     

空间自旋目标平动补偿与微动特征提取方法

针对空间自旋目标平动补偿与微动(m-D)特征提取问题,提出一种基于延时共轭相乘和微动分解的平动补偿与特征提取方法。该方法通过延时共轭相乘处理实现目标加速度估计,然后构建冗余的微动原子集,对加速度补偿后信号进行微动分解补偿,通过搜索补偿信号的最大谱峰获取目标的微动特征与速度信息。仿真试验表明,所提方法能够有效估计空间自旋目标的运动参数,并快速提取其微动特征。     

Mesh-dependence of Material with Softening Behavior

The issue of mesh-dependence emerges when the conventional continuum damage model is applied to handling the softening behavior. In order to circumvent the mesh-dependence, the non-local theory is introduced into the conventional damage model and the finite element formulas are derived for two-dimensional gradient-enhanced damage model. A new element is proposed in which the basic unknown quantities are displacement, non-local equivalent strain and the gradient of non-local equivalent strain. The element and constitutive equation proposed in this article are added to the finite element software ABAQUS through user subroutine UEL. Numerical results show that the gradient-enhanced damage model can eliminate the mesh-dependence and is effective for dealing with the issue of softening behavior.     

烧生活垃圾流化燃烧炉方案设计

本文设计了一台日处理量２ｔ／ｄ的烧垃圾的漩流化床焚烧炉模化装置，并进行了相应的热力计算，此装置可作为研究燃烧低热闰圾的重要设备。     

三硝基间苯二酚中硫酸测定的研究

本文研究了硫酸钡在氨水溶液中与ＥＤＴＡ的反应条件，提出用ＥＤＴＡ滴定法测定三硝基间苯二酚中的硫酸。本法准确度较高，稳定性好，操作简单，与样品标准值对照，结果满意。     

A novel approach for predicting inlet pressure of aircraft hydraulic pumps under transient conditions

Cavitation caused by insufficient suction is a major factor that influences the life of aircraft pumps. Currently, pressurizing the tank can solve the cavitation problem under steady large-flow conditions. However, this method is not always effective under transient conditions (from zero flow to full flow in a very short time). Moreover, to apply and design other measures, such as a boost impeller, the suction dynamics during the transient period must be investigated. In this paper, a novel approach based on the pressure wave propagation theory is proposed for predicting the inlet pressure of an aircraft pump under transient conditions. First, a dynamic model of a typical aircraft pump is established in the form of differential equations. Then, the transient flow model of the inlet line is described using momentum and continuity equations, and the governing equations are discretized by the method of characteristics and the finite difference method. The simulated results are in good agreement with the results from verification tests. Further simulation analysis indicates that the wave velocity and transient time may influence the inlet and reservoir pressure as well as the size of the inlet line. Finally, solutions for upgrading the inlet pressure are discussed. These solutions provide guidelines for designing inlet installations.     

一种分形DGS单元结构设计及其在微带电路中的应用

文章设计出了一种新型的DGS单元——Minkowski分形哑铃DGS单元，并将其应用于微带电路的设计中。利用HFSS软件对相关电路模型进行仿真，结果表明，具有相同尺寸的一阶分形单元电路（缺口深度P=2／3）与普通的哑铃形DGS单元电路比较，谐振频率降低了1．1GHz。利用此分形单元设计电路，可以达到电路小型化的效果。     

An extended chirp scaling algorithm for spaceborne sliding spotlight synthetic aperture radar imaging

A system impulse response with low sidelobes is critical in synthetic aperture radar（SAR） images because sidelobes contribute to noise and interfere with nearby scatterers. However,the conventional tricks of sidelobe suppression are unable to be exactly applied to the case of spaceborne sliding spotlight SAR due to great azimuth shifts in both time and frequency domains. In this paper, an extended chirp scaling algorithm is presented for spaceborne sliding spotlight SAR data imaging. The proposed algorithm firstly uses the spectral analysis（SPECAN） technique to avoid the azimuth spectrum folding effect and then employs the chirp scaling（CS） algorithm to achieve data focusing, i.e., the so-called two-step approach. To suppress the sidelobe level, an efficient strategy for the azimuth spectral weighting which only involves matrix multiplications and short fast Fourier transformations（FFTs） is proposed, which is a post-process executed on the focused SAR image and particularly simple to be implemented. The SAR image processed by the proposed extended CS algorithm is very precise and perfectly phase-preserving. In the end, computer simulation results verify the analysis and confirm the validity of the proposed algorithm.     

超大型光学镜面面形的纳米定位技术

电容式传感器在纳米级测试中得到了广泛的应用，但是对环境条件要求较高，检测中温、湿度的变化、传感器本身结构乃至其电路性能等因素，将直接影响测量的准确度和灵敏度。介绍了大型天体望远镜光学镜面面形的控制方法和工作原理。该大型天体望远镜Φ１０ｍ的主镜由３６块对角线长１．８ｍ的六角形子镜拼接而成，应用电容测微技术使此超大型镜面的共面性达到纳米量级的定位控制。通过检测原理的分析，阐述了电容式传感器在使用中提高其准确度和长期稳定性的理论分析和具体技术措施，并针对国内正在研制的ＬＡＭＯＳＴ超大型天体望远镜实际应用环境和技术指标要求，提出新的差动式传感器，并采用新材料和高集成度的进口新器件，以满足传感器在温、湿度变化大的条件下实时监测的要求。