Barge traffic control in the lower Odra River using DGPS

The increase in the barge-carried cargo volumes in the lower Odra River area necessitates the tracking of barge traffic in order to ensure the safety of navigation. The Dziwnow DGPS reference station, designed for marine traffic, is located near the mouth of the Odra River. The paper presents the results of investigation into the availability of DGPS signal transmitted by the Dziwnow reference station in the lower Odra River area between Kostryd and Szczecin.     

Plasma flow variations and energetic protons upstream of the earth’s bow shock: A statistical study

Foreshock is a special region located upstream of the Earth’s bow shock characterized by the presence of various plasma waves and fluctuations caused by the interaction of the solar wind plasma with particles reflected from the bow shock or escaping from the magnetosphere. On the other hand, foreshock fluctuations may modify the bow shock structure and, being carried through the magnetosheath, influence the magnetopause. During the years 1995–2000, the INTERBALL-1 satellite made over 10,000 hours of plasma and energetic particles measurements in the solar wind upstream of the Earth’s bow shock. We have sorted intervals according to the level of solar wind ion flux fluctuations and/or according to the flux of back-streaming energetic protons. An analysis of connection between a level of ion flux fluctuations and fluxes of high-energy protons and their relation to the IMF orientation is presented.     

XY502胶粘剂最佳制样的选择与探讨

XY502胶粘剂的测试结果始终处于不稳定状态，通过大量的对比试验与研究，确定出XY502胶粘剂的最佳制样方法：混合甲乙组份2小时，打磨方式达到标准要求，同时在房间里配除湿机来把湿度固定在45％-55％范围内，胶接及停放温度对结果影响很大，必须把胶接及停放温度控制在25℃-30℃之间，这样XY502的测试结果才符合标准，以上方法才是最佳的制样方法。     

An integrated Engineered Closed/Controlled EcoSystem for a lunar base.

Long-term human missions in space, such as the establishment of a human-tended lunar base, require autonomous life support systems. A Lunar Engineered Closed/Controlled EcoSystem (LECCES) can provide autonomy by integrating a human module with support plant and animal modules, and waste treatment subsystems. Integration of physical/chemical (P/C) and biological waste treatment subsystems can lead to viable and operational bioregenerative systems that minimize resupply requirements from Earth. A top-level diagram for LECCES is developed based on the human module requirements. The proposed diagram is presented and its components are discussed.     

Small scale solar wind ion flux and IMF quasi-harmonical structures in the earth''s foreshock: INTERBALL-1 and MAGION-4 observations

High time resolution data obtained by VDP and FM-31 instruments onboard INTERBALL-1 spacecraft were used to study the small-scale correlation between solar wind ion flux and magnetic field magnitude in the Earth's foreshock. Correlated quasi-harmonic structures were found simultaneously in ion flux and magnetic field data. Statistical analysis of these structures was done and a summary of obtained results is presented. Multipoint observations by INTERBALL-1 and MAGION-4 were used to estimate spatial correlation of small quasi-harmonic structures.     

Physics of Substorm Growth Phase,Onset, and Dipolarization

A new scenario of substorm growth phase, onset and dipolarization during expansion phase and the corresponding physical processes are presented. During the growth phase, as a result of enhanced plasma convection, the plasma pressure and its gradient continue to be enhanced over the quiet-time values in the plasma sheet. Toward the late growth phase, a strong cross-tail current sheet is formed in the near-Earth plasma sheet region, where a local magnetic well is formed. The equatorial plasma beta (β _eq ) can reach a local maximum with value larger than 50 and the cross-tail current density can be enhanced to over 10nA/m² as obtained from 3D quasi-static magnetospheric equilibrium solutions for the growth phase. The most unstable kinetic ballooning instabilities (KBI) are expected to be located in the tailward side of the strong cross-tail current sheet region. The field lines in the most unstable KBI region map to the transition region between the region-l and region-2 currents in the ionosphere, which is consistent with the observed initial brightening location of the breakup arc in the intense proton precipitation region. The KBI explains the AMPTE/CCE observations that a low frequency instability with a wave period of 50–75 seconds is excited about 2–3 min prior to substorm onset and grows exponentially to a large amplitude at the onset of current disruption (or current reduction). At the onset of current disruption higher frequency instabilities are excited so that the plasma and electromagnetic field fluctuations form a strong turbulent state. Plasma transport takes place due to the strong turbulence to relax the ambient plasma pressure profile so that the plasma pressure and current density are reduced and the ambient magnetic field intensity increases by more than a factor of 2–3 in the high-β _eq region and the field line geometry recovers from tail-like to dipole-like – dipolarization.     

一种基于协方差矩阵重构的相干信源DOA估计算法

针对空间相干信源的波达方向估计问题,提出了一种基于协方差矩阵重构的TSVD-ESPRIT算法。它利用包含所有信源信息的特征向量构造Toeplitz协方差矩阵,避免了阵列有效孔径的损失,分辨率高且稳定性好;并且利用ESPRIT算法代替MUSIC算法进行DOA估计,避免了谱峰搜索,大大降低了计算量。数据仿真和分析证明了该算法的正确性和有效性。     

飞行器阵风响应的CFD-6DOF仿真分析

飞行器在大气中飞行,不可避免地受到阵风的影响。阵风所附加的气动载荷引发飞行器飞行状态的改变,过大幅值的阵风影响飞行的性能与安全。针对这种状况,首先采用改进的Lamb-Ossen涡模型,建立尾涡形式的阵风场;然后采用基于CFD技术的非定常N-S方程求解,并在计算网格中引入"网格速度"来模拟阵风,对SWIM(Subsonic Wall Interference Model)尾涡中的定常气动特性进行验证;最后通过CFD-6DOF的耦合,对SWIM俯冲穿越尾涡场的飞行轨迹进行研究。结果表明:计算结果与实验值符合较好;SWIM在尾涡中飞行时出现抖动、下沉、改变飞行状态、剧烈翻转的现象,与实际飞行器进入尾涡中的轨迹特性类似。     

垂直起降飞行器的发展动态和趋势分析

垂直起降飞行器因对起降地点要求低而得到了广泛的应用。按照动力方式对垂直起降飞行器进行分类,剖析了不同类型的飞行器,归纳了相关的关键技术问题,并重点介绍了近年来垂直起降飞行器的发展动态,尤其强调了一些创新设计的思路。然后,展望了垂直起降飞行器的发展趋势,以期为垂直起降飞行器设计人员面对不同的任务要求和特点提供一定的参考价值。