PSK转换法产生直序扩频MSK信号研究

通过 PSK转换法产生 MSK信号的数学模型的进一步推导和计算机仿真 ,研究了不同长度的扩频码对延时相干解调扩频 MSK信号的影响。然后进行了 PSK转换法产生扩频 MSK信号的系统实验     

扩频序列容错能力分析

提出了扩频码（序列）容错能力影响扩频系统的性能的问题。分析了二进制序列集合作相关检测时的容错能力与序列的相关特性之间的关系，给出容错能力的理论界限；研究了相关器输出判决门限的确定及相关峰检测概率与扩频序列的容错能力之间的关系。     

Estimation of the solar proton spectrum in the GLE70 event

The GLE event on December 13, 2006 as observed by network station neutron monitor data is investigated (is considered). The GLE energetic spectrum suggested for this event is estimated taking into account the primary differential spectrum of galactic cosmic rays, coupling coefficients and integral multiplicities of concrete detectors at different latitudes and levels of observation. It is noted that the additional increase of solar protons is also manifested in the ionization chamber ASK-1 data at the Yakutsk station.     

T cell regulation in microgravity – The current knowledge from in vitro experiments conducted in space,parabolic flights and ground-based facilities

Dating back to the Apollo and Skylab missions, it has been reported that astronauts suffered from bacterial and viral infections during space flight or after returning to Earth. Blood analyses revealed strongly reduced capability of human lymphocytes to become active upon mitogenic stimulation. Since then, a large number of in vitro studies on human immune cells have been conducted in space, in parabolic flights, and in ground-based facilities. It became obvious that microgravity affects cell morphology and important cellular functions. Observed changes include cell proliferation, the cytoskeleton, signal transduction and gene expression. This review gives an overview of the current knowledge of T cell regulation under altered gravity conditions obtained by in vitro studies with special emphasis on the cell culture conditions used. We propose that future in vitro experiments should follow rigorous standardized cell culture conditions, which allows better comparison of the results obtained in different flight- and ground-based experiment platforms.     

舰载机拦阻着舰载荷谱编制技术

舰载机舰面载荷谱是航母服役环境下飞机结构长寿命和耐久性设计的关键。依据舰载机在拦阻着舰过程中的舰面载荷特点，论述了现有编制方法的局限性，结合多体动力学仿真模型探讨了载荷谱编制的方案和流程，建立了拦阻着舰多体动力学运动方程和仿真模型，并进行了仿真计算。通过对舰载机飞行剖面以及拦阻着舰任务剖面特点分析，确定了飞机拦阻着舰任务段载荷谱的主要工况以及比例关系，编制出飞机拦阻着舰过程的重心谱，绘制出载荷谱超越曲线，为舰载机的设计载荷谱编制提供依据，具有较高的工程应用价值。     

频偏校准技术研究

对用频谱仪测定调频指数和频偏的近载频比值法（CFSR）进行了研究。给出了方法的基本原理、测量误差、不同频偏指数适用范围,以及测量不准确度。讨论了大频偏指数时的调制频谱替代法（FMSS）。     

激波波后氮分子发射光谱的测量

利用多通道光学分析仪测量激波波后不同时刻高温氮气的辐射光谱发现，辐射随时间发生强烈的变化。在非平衡态和平衡态，光谱的各条谱线强度有明显的差别。光谱的结构特征也依赖于激波的速度。     

基于声光技术的扩频信号循环谱的检测

扩频信号是被伪随机码调制的周期信号,因此它应被建模为循环平稳随机信号.基于循环平稳随机信号的谱相关理论,提出了一种采用基于声光信号处理技术的扩频信号循环谱检测方法.通过研究扩频信号的循环频率、循环功率谱和基于时间积分的声光循环平稳处理模型,利用声光循环平稳时间积分相关器,在循环频率处对扩频信号的声光相关函数(循环谱)进行检测.相比于传统的能量检测方法,循环谱检测方法具有更好的检测性能;对于噪声和干扰,无论是平稳的、还是非平稳的,循环谱检测方法都具有较强的抗干扰能力,仿真结果证明了其有效性.     

DS/FH混合系统多址干扰抑制

根据DS-CDMA(Direct Sequence Code Division Multi-Access)系统中多用户检测的思想,分析了并行干扰抵消PIC(Parallel Interference Cancellation)对系统性能的影响,在此基础上,提出了采用部分并行干扰抵消PPIC(Partial Parallel Interference Cancellation)技术来抑制DS/FH SSMA(Direct Sequence/Frequency Hopping Spread Spectrum Multi-Access)混合系统中的多址干扰MAI ( Multi-Access Interferences).推导了闭环形式的误码率公式,得到系统性能评估的上限表达式.仿真结果表明,采用PPIC技术可有效的提高DS/FH SSMA系统的抗多址干扰的能力,因而可以提高系统的容量.仿真是建立在AWGN信道下的,对于衰落信道和低信噪比环境下,系统的性能会有一定程度的降低.      

一种空间目标RCS序列的姿态异常检测方法

准确、快速判断空间目标姿态运动模式异常,对于空间目标监测具有重要意义。针对空间目标雷达散射截面 (Radar Cross Section,RCS)序列,提出一种基于小波包分解（Wavelet Packet Decomposition,WPD）能量谱特征的无监督机器学习异常检测方法,并采用单类支持向量机(One Class Support Vector Machine,OCSVM)验证异常检测效果。设置了几种典型异常场景进行仿真分析,试验结果表明,该方法能有效检测出三轴稳定类空间目标发生失稳旋转的姿态异常。相比于传统统计参数特征、小波变换统计参数特征及能量特征的姿态判别方法,具有检测概率高、鲁棒性好的特点。