Spectroscopic data and Stark broadening of Cu I and Ag I spectral lines: Selection and analysis

Optical emission and linear laser absorption spectroscopy techniques were used in investigation of plasma with copper and silver admixture. The method of selection of spectral lines and spectroscopic data with the aim of diagnostics of multicomponent air plasma with two metal vapors admixture was developed. Energy level populations behavior on the Boltzmann plot were used for Cu I and Ag I spectroscopic data selection. In this way the selection of spectroscopic data for some of Cu I and Ag I lines was realized. Stark broadening parameters of Cu I and Ag I were examined. Experimentally obtained temperature and electron density radial distributions were used in the calculation of plasma composition in the assumption of local thermodynamic equilibrium. Linear laser absorption spectroscopy was used to examine the state of plasma.     

中心等离子体片的地向对流型高速流

在GSM坐标系下, 利用TC-1卫星和Cluster/C1卫星上4s分辨率的磁场和热离子探测数据, 对中心等离子体片内的地向对流型高速流进行了统计研究(-19 Re < x< -9 Re, |y| < 10 Re, |z|< 5 Re). 统计结果表明, 地向对流型高速流会在15 Re以内出现``刹车', 在11.5 Re附近时出现``缺失'. 进一步对其速度特征进行统计分析. 结果显示, 在中心等离子体片内的高速流, 其运动方向主要为地向, 晨昏和南北方向的运动明显较弱; 在对流型高速流的地向输运过程中, 其峰值速度没有明显的下降; 在近地13 Re以内, 等离子体片内的地向对流型高速流具有较强的垂直磁力线运动速度. 这意味着对流型高速流在近地15 Re以内的“刹车”不是由高速流晨昏或南北方向的偏转造成的. 高速流在11.5 Re附近时出现的``缺失'可能与在15 Re以内出现``刹车'密切相关. TC-1卫星和Cluster卫星的观测为了解中磁尾重联高速流地向输运过程及亚暴膨胀相触发提供了重要的观测依据.      

Universal scaling laws for fully-developed magnetic field turbulence near and far upstream of the Earth’s bow shock

We analyze the multifractal scaling of the modulus of the interplanetary magnetic field near and far upstream of the Earth’s bow shock, measured by Cluster and ACE, respectively, from 1 to 3 February 2002. The maximum order of the structure function is carefully estimated for each time series using two different techniques, to ensure the validity of our high-order statistics. The first technique consists of plotting the integrand of the pth order structure function, and the second technique is a quantitative method which relies on the power-law scaling of the extreme events. We compare the scaling exponents computed from the structure functions of magnetic field differences with the predictions obtained by the She–Lévêque model of intermittency in anisotropic magnetohydrodynamic turbulence. Our results show a good agreement between the model and the observations near and far upstream of the Earth’s bow shock, rendering support for the modelling of universal scaling laws based on the Kolmogorov phenomenology in the presence of sheet-like dissipative structures.     

气动加热与热响应耦合分析及试验研究

文章介绍了Ma（马赫数）＜6的飞行器典型部位的气动加热与热响应耦合分析及试验验证技术。气动加热计算模块采用的是工程算法,同时将其集成到自主开发的结构有限元三维温度场计算ASTSA软件平台上,实现了气动加热与热响应耦合分析功能。在结构地面热试验方面,成功研发了全方程热流密度PLC控制热模拟试验系统,并利用该系统进行了高速飞行器结构气动加热与热响应耦合地面模拟试验。试验与数值分析的结果对比显示,二者吻合较好,验证了本数值分析方法的正确性。     

Vertical shear at the equatorial F-region ionosphere during post-sunset hours

The characteristics of the equatorial F-region zonal plasma drift during post-sunset period have been investigated using the multi-frequency HF Doppler radar. The pattern of the zonal plasma drift is such that it starts with a westward drift during the pre-sunset hours, followed by an eastward drift shortly after the E-region sunset. The zonal plasma drift is characterized by the presence of a positive vertical shear around the post-sunset period and maximum shear is observed at the time of the peak of the pre-reversal enhancement in the vertical drift. The presence of vertical shear in the zonal drift is associated with the post-sunset velocity vortex existing at the equatorial F-region.     

用于新型雷达/红外无源复合诱饵的等离子体参数选择

根据电磁波在分层介质中阻抗匹配原理,计算了非均匀非磁化等离子体平行与垂直极化波的功率反射系数。基于碱金属盐的高温电离特性,以功率反射系数为研究对象,对雷达无源诱饵用等离子体的厚度、温度和电子密度分布等参数选择进行了分析,并根据所选择的参数讨论了入射角对无源诱饵应用的影响。     

用于非线性有源天线的耦合锁相环特性分析

为实现非线性有源天线阵波束扫描,研究了互耦锁相环(PLL)的基本特性。通过对互耦PLL的相位动力学方程的稳定性进行分析,建立了具有延时的阵列模型;通过调节环路延时,互耦PLL不同的非线性动力学特性;采用四单元的耦合锁相环阵列实验电路对理论分析进行了验证,从而提出了在设计基于耦合锁相环的非线性有源天线时,必须对环路延时进行控制,防止环路出现振荡和混沌现象。     

再入航天器表面亚波长等离子体薄层对微波信号影响效应研究

为了建立电磁波在亚波长等离子体薄层中传播的物理数学模型,并针对通信频段的电磁波,研究电磁波在再入航天器表面等离子体薄层中的透射问题,相关研究成果可为再入航天器通信“黑障”现象研究提供理论基础。模型从麦克斯韦方程组出发,采用微分薄层法进行数值求解,获得了不同等离子体密度条件下亚波长等离子体中目标电磁波的透射特性及传播规律,揭示了截止反射效应和碰撞吸收效应在其中发挥的作用。本研究对于深入了解亚波长碰撞等离子体薄层中电磁波的传播过程具有意义。     

挠性充液航天器超近程逼近段动力学建模与控制

超近程逼近过程中,服务航天器为刚柔液耦合的复杂系统,单摆等液体晃动模型不再适用,对这种工况下的航天器进行了动力学建模与控制的研究。采用虚功率原理推导了一种新的适用于三轴推力作用下的液体晃动等效模型,通过引入相对位置导引矢量与相对位置误差矢量,建立了相对轨道误差动力学模型,结合相对姿态动力学模型,得到超近程逼近段的刚柔液耦合的相对轨道姿态动力学模型。针对模型存在的不确定性和未知干扰,设计了基于滑模估计器的相对姿轨耦合控制律。通过数学仿真验证了控制律的有效性,仿真中的晃动结果与Flow-3D结果能够吻合,验证了晃动模型的合理性。     

飞翼布局飞行器等离子体激励滚转操控试验

飞翼布局飞行器采用多个气动舵面共同作用来控制飞行,常规气动舵面的结构复杂,在大迎角时由于流动分离,舵面操纵效率显著降低。等离子体激励器具有结构简单、重量轻和响应快等优势,常被用在流动控制上。本文利用激励器抑制单侧翼面流动分离产生不对称的气动力,对飞翼布局飞行器滚转通道的控制进行了试验研究,得出了激励器在飞行器上的最优布置位置和最佳控制参数,并和常规副翼舵面滚转操控效果进行了对比。结果表明:布置于内翼、中翼前缘的等离子体激励器能够获得最佳的滚转控制效果;激励器调制频率对飞行器滚转控制效果的影响较大,而激励电压对滚转控制效果的影响较小;与常规副翼相比,等离子体激励器在大迎角时对滚转通道的操控效果优于副翼。