Electron coronal density irregularity\overline {n^2 } /(\bar n)^2 from measurements of K-coronal and lyman lines brightnesses

We propose a technique to derive the coronal density irregularity factor , wheren is the electron density. The absolute photometric comparison between the intensity of UV lines and the white-light K-coronal polarized brightness (pB) provides an unique constraint on the inhomogeneity of the corona. The ratio of the measured H I Lyman (Ly-) line intensity to the resonant-scattering dominated H I Lyman (Ly-) intensity can be used to extract the collisonal component of the Ly-. This component yields an estimate of . The quantity is then obtained from white-light K-coronal measurements. The use of lines of the same atomic species minimizes the effects due to outflow velocities (i.e., Doppler dimming), and reduces the errors introduced by the uncertainties in the ionization balance, the atomic parameters, and the solar abundances. The UVCS/SOHO unique capability of performing cotemporal and cospatial measurements of the Ly- and Ly- lines, and ofpB makes this instrument ideal for implementing this technique.     

基于高精度径向测速的宽带雷达单诱饵速度识别法

由于宽带相控阵雷达测速精度的大幅度提高，现提出了一种新的目标识别方法——基于高精度径向测速的单诱饵速度识别法，并对其识别原理、识别性能进行了详细阐述和定量分析。通过理论推导和计算机仿真计算，验证了该识别方法在宽带相控阵雷达监视诱饵释放过程中应用的有效性。     

某光电检测仪典型问题分析及解决

某光电检测仪器用于实时精确检测设备的动态安装方位准确度。就该仪器使用过程中出现的光能量分布不均、二次像点现象严重及测角零位漂移等几个典型问题进行分析,提出并采取了相应的解决措施,为以后解决类似的问题提供了技术途径。     

Selection of candidate salad vegetables for controlled ecological life support system

Higher plants, as one of the essential biological components of CELSS, can supply food, oxygen and water for human crews during future long-duration space missions and Lunar/Mars habitats. In order to select suitable leaf vegetable varieties for our CELSS Experimental Facility (CEF), five varieties of lettuce (“Nenlvnaiyou”, “Dasusheng”, “Naichoutai”, “Dongfangkaixuan” and “Siji”), two of spinach (“Daye” and “Quanneng”), one of rape (“Jingyou No. 1”) and one of common sowthistle were grown and compared on the basis of edible biomass, and nutrient content. In addition, two series of experiments were conducted to study single leaf photosynthetic rates and transpiration rates at 30 days after planting, one which used various concentrations of CO₂ (500, 1000, 1500 and 2000 μmol mol⁻¹) and another which used various light intensities (100, 300, 500 and 700 μmol m⁻² s⁻¹). Results showed that lettuce cvs. “Nenlvnaiyou”, “Siji” and “Dasusheng” produced higher yields of edible biomass; common sowthisle would be a good source of β-carotene for the diet. Based on the collective findings, we selected three varieties of lettuce (“Nenlvnaiyou”, “Dasusheng” and “Siji”) and one of common sowthistle as the candidate crops for further research in our CEF. In addition, elevated CO₂ concentration increased the rates of photosynthesis and transpiration, and elevated light intensity increased the rate of photosynthesis for these varieties. These results can be useful for determining optimal conditions for controlling CO₂ and water fluxes between the crops and the overall CELSS.     

航天器星敏感器自主定位方法及精度分析

用星敏感器和地平仪测量星光与地平之间的“星光抑角”为观测量，利用推广卡尔曼滤波方法实时估计航天器的最佳位置，使航天器在失去地面遥控的情况下，能够自主准确地确定运行轨道。由于航天器自主定位系统在工作期间会受到硬、软件等诸多因素的影响，因而使其定位精度达不到预计要求。在此我们通过大量仿真计算，指出一些对自主定位系统精度影响较大的因素，并对它们进行了比较分析。     

非相干有源诱偏抗反辐射武器效果分析

从反辐射武器导引头瞄准误差的角度,对非相干有源诱偏抗反辐射武器的干扰效果进行分析。     

基于绿色光源LED的开关型恒流驱动电路设计

针对LED的特点提出开关型恒流驱动电路,通过电流与电压负反馈技术的采用,将LED的输入电流控制在一个稳定的电流数值下,同时使电路防止过电压的能力提高,可靠性大为增强.     

主动雷达抗拖曳式诱饵干扰的角度提取方法

通过对拖曳式有源雷达诱饵干扰的分析,得到了平衡状态下对导引头测角值进行数据积累且取均值后,导引头将指向大功率辐射源的结论.在诱饵信号从功率上压制载机回波信号的前提下,对导引头处于平衡状态时的测量角公式进行数学推导进而求得小功率辐射源(载机)的角度.结合比例导引规律,通过飞行弹道仿真验证了雷达型空空导弹应用上述方法可获得...     

拖曳式诱饵释放时机和释放过程研究

在拖曳式诱饵的使用中,有两个问题必须考虑：一是诱饵释放时机;二是诱饵释放过程。首先对诱饵的释放时机进行论述,给出诱饵最佳释放时机;然后采用数学方法,建立诱饵释放过程模型,对其进行仿真,得到了较为准确的仿真结果。     

Dynamic simulation of aerial towed decoy system based on tension recurrence algorithm

Dynamic model of aerial towed decoy system is established and simulations are performed to research the dynamic characteristics of the system. Firstly, Kinetic equations based on spinor are built, where the cable is discretized into a number of rigid segments while the decoy is modeled as a rigid body hinged on the cable. Then tension recurrence algorithm is developed to improve computational efficiency, which makes it possible to predict the dynamic response of aerial towed decoy system rapidly and accurately. Subsequently, the efficiency and validity of this algorithm are verified by comparison with Kane's function and further validated by wind tunnel tests.Simulation results indicate that the distance between the towing point and the decoy's center of gravity is suggested to be 5%–20% of the length of decoy body to ensure the stability of system.In up-risen maneuver process, the value of angular velocity is recommended to be less than0.10 rad/s to protect the cable from the aircraft exhaust jet. During the turning movement of aircraft, the cable's extent of stretching outwards is proportional to the aircraft's angular velocity.Meanwhile, the decoy, aircraft and missile form a triangle, which promotes the decoy's performance.