基于BLUE的多窗口谱估计

文章提出了一种基于BLUE的多窗口功率谱估计算法。该算法是在无偏估计的约束条件下，使其方差最小化而得到的特征谱的最佳线性组合。通过仿真实例分析得到，与自适应的MTM相比，该算法的计算量大大减小了。由于正弦窗具有解析的表达式，不需要进行特征值分解，并且有良好的统计性能，因此，使用正弦窗的MTM可以进一步降低计算量并改善估计性能。     

发散波束在媒质界面上的Goos-H(a)nchen位移与焦移

在全反射中研究了发散波束在两种不同媒质界面上Goos-H(a)nchen位移与焦移.首先,通过建立发散光束全反射简单光线模型来显示焦移的形成.然后,从波动光学出发,利用Fourier光学中的角谱法推导出Gauss发散波束入射下Goos-H(a)nchen位移和焦移的近似关系式.结果表明,由Carniglia 和 Brownstein 针对于均匀波束提出的Goos-H(a)nchen位移和焦移的微分关系式同样也适用于Gauss发散波束入射的情况.最后,通过数值模拟总结出了焦移的一些不同于Goos-H(a)nchen位移的特殊性质.这些特殊性质的发现为改善现有实验和工程精度提供了新路径.     

基于C语言实现的数据加DES算法

DES体制是ISO颁布的数据加密标准，通过对DES算法的分析，提出了用C语言实现数据加密标准DES算法，通过循环或迭代，将简单的基本运算(例如左移、右移、模2加法等)和变换(选择函数、置换函数)构造成数据流的非线性变换(加密变换或解密变换)，从而实现对计算机数据进行密码保护。着重介绍了用C语言实现其加密的主要过程。     

最大熵谱估计及其在电子战中的应用

介绍了最大熵谱估计的原理，与快速傅里叶变换相比，它有低的旁瓣和高的分辩力。同时讨论了在电子战方面的应用。     

质谱薄膜联用小型气体泄漏检测仪研制

传统的监测技术在往往采用单一的方法或者采用质谱加色谱联用的技术，设备大都比较笨重，操作复杂，随着现代工业的发展，急需研制体积小，质量轻在便携式仪器，同时具备灵敏度高，分辨能力强，可靠性高等特点的检测仪。利用质谱检测的高分辨能力和敏感膜的高灵敏度，文章提出了质谱和加薄膜联用进行气体泄漏监测的全新思路，并主要论述了检测仪的研制和性能实验研究等内容，最后结合其在航天领域的应用，对甲基膨，无水肼等气体进行     

Alleviation of spike stall in axial compressors utilizing grooved casing treatment

This article deals with application of grooved type casing treatment for suppression of spike stall in an isolated axial compressor rotor blade row. The continuous grooved casing treatment covering the whole compressor circumference is of 1.8 mm in depth and located between90% and 108% chord of the blade tip as measured from leading edge. The method of investigation is based on time-accurate three-dimensional full annulus numerical simulations for cases with and without casing treatment. Discretization of the Navier–Stokes equations has been carried out based on an upwind second-order scheme and k-w-SST(Shear Stress Transport) turbulence modeling has been used for estimation of eddy viscosity. Time-dependent flow structure results for the smooth casing reveal that there are two criteria for spike stall inception known as leading edge spillage and trailing edge backflow, which occur at specific mass flow rates in near-stall conditions. In this case, two dominant stall cells of different sizes could be observed. The larger one is caused by the spike stall covering roughly two blade passages in the circumferential direction and about 25% span in the radial direction. Spike stall disturbances are accompanied by lower frequencies and higher amplitudes of the pressure signals. Casing treatment causes flow blockages to reduce due to alleviation of backflow regions, which in turn reduces the total pressure loss and increases the axial velocity in the blade tip gap region, as well as tip leakage flow fluctuation at higher frequencies and lower amplitudes. Eventually, it can be concluded that the casing treatment of the stepped tip gap type could increase the stall margin of the compressor. This fact is basically due to retarding the movement of the interface region between incoming and tip leakage flows towards the rotor leading edge plane and suppressing the reversed flow around the blade trailing edge.     

阵列NaI（T1）探测器γ能谱合成方法探讨

介绍两路或多路NaI（T1）探测器γ能谱数据的合成方法及初步成果，以“特征峰叠加”的方法对^133Cs和^60Co的仪器谱进行单峰和双峰的叠加试验，为天然γ能谱合成提供依据。实验表明，“特征峰叠加”的方法可较好地反映各仪器谱合成前的特性，有很好的应用前景。     

一种基于FFT IPcore的实时频谱处理方案

本文针对飞机地面电源车的电源品质中畸变频谱的大数据量和实时性特点提出了一种基于 FFT IPcore的实时频谱处理方案。本方案以DFT蝶形变换为理论基础，在FPGA上通过对FFT IPcore的配置和配套逻辑的编写，实现了大数据量的实时频谱处理，并最终以Matlab仿真、XST仿真以及Chipscope实时数据对比验证了方案的正确性和实时性。     

Calculation of the effect of opacity in the solar spectral lines of carbon ions

In this paper, using the intensity ratio of carbon ions emission lines, we determined the optical depths at the line center of the CI at about 165.7 nm, CII at about 133.5 nm, CIII at about 117.5 nm and CIV at about 154.9 nm emission lines by escape factor treatment. For CI and CII emission lines, we discuss the intensity ratio of two lines arising from the common upper levels; while for CIII and CIV emission lines, we discuss the intensity ratio of two lines arising from the common lower levels. By introducing the measured abundance of carbon and the results of ionization balance calculations, we make an estimate of the line-of-sight physical thickness of the regions of carbon ions. This discussion will provide some results in the discussion of opacity on the solar ultraviolet (UV) or extreme-ultraviolet (EUV) spectrum.     

扩频信号声光相关解调技术

声光相关技术在检测宽带微弱信号中有很大的潜力，提出在射频上用声光相关器对扩频信号做相关运算的方案，给出扩频信号的快速捕获、精密跟踪和信息解调的方法，并设计了实验系统，结果得到了验证。