HTPB官能度数学模型建立

为了研究自由基型液体端羟基聚丁二烯预聚物(HTPB)体系官能度分布情况,对其化学合成中自由电子转移情况进行了分析,并通过数学统计的方法对其官能度分布进行理论数值模拟,建立了适用于自由基型HTPB官能度分布的函数关系式,并与GPC所测结果进行对比。结果显示,计算所得函数关系式与测试数据吻合结果较好,数值模拟结果准确性较高;自由基聚合生产的不同批次的HTPB官能度分布存在较大差异,单官能度分子含量可从5%~24%,二官能度分子的含量可从50%~81%;利用数学统计得到的函数关系,可将复杂的HTPB官能度测试转变为简单的分子量分布测试。     

Interplanetary scintillations of the radio source ensemble at the maximum of cycle 24 of solar activity

The results of the interplanetary scintillation observations performed in the period of the maximum of solar activity from April 2013 to April 2014 on the BSA LPI radio telescope at the frequency 111MHz are presented. Fluctuations of the radio emission flux were recorded round the clock for all sources with a scintillating flux of more than 0.2 Jy falling in a strip of sky with a width of 50° over declinations corresponding to a 96-beam directional pattern of the radio telescope. The total number of sources observed during the day reaches 5000. The processing of the observational data was carried out on the assumption that a set of scintillating sources represents a homogeneous statistical ensemble. Daily two-dimensional maps of the distribution of the level of scintillations, whose analysis shows the strong nonstationarity and large-scale irregularity of the spatial distribution of solar wind parameters, were constructed. According to maps of the distribution of the level of scintillations averaged over monthly intervals, the global structure of the distribution of the solar wind was investigated in the period of the maximum of solar activity, which was found to be on the average close to spherically symmetric. The data show that on a spherically symmetric background an east–west asymmetry is observed, which indicates the presence of a large-scale structure of a spiral type in the solar wind.     

Analysis and synthesis of the information-controlling system channels to prevent critical operating conditions of the helicopter flight

This paper deals with the technical features of designing an information-controlling system to prevent critical operating conditions of the helicopter flight, a technique for evaluating its effectiveness, analysis and synthesis of the measurement channels, forming of warning signals, and information support of the crew in abnormal situations.     

Determination of Gas-Generator Fuel Capacity for Hybrid Aerial Underwater Vehicles with Airfoil Cavity-Forming System

We determine the behavior of onboard gas-generator flowrate for generating the cavitation flow around a hybrid aerial underwater vehicle by using an annular wing on the underwater trajectory section.     

To selection of the model fluid for hydrogen simulation in testing of seals

The paper discusses the applicability of cold gaseous nitrogen as a model working fluid in testing the hydrogen pump seals for power plants by three-dimensional modeling.     

Thermally excited vibrations of aircraft structural elements

This paper considers the axisymmetric transverse vibrations of aircraft nonuniform structural elements that are introduced by a thermal shock. Analytical solutions have been obtained and their numerical analysis has been performed.     

Results of solar observations by the CORONAS-F payload

The CORONAS-F mission experiments and results have been reviewed. The observations with the DIFOS multi-channel photometer in a broad spectral range from 350 to 1500 nm have revealed the dependence of the relative amplitudes of p-modes of the global solar oscillations on the wavelength that agrees perfectly well with the earlier data obtained in a narrower spectral ranges. The SPIRIT EUV observations have enabled the study of various manifestations of solar activity and high-temperature events on the Sun. The data from the X-ray spectrometer RESIK, gamma spectrometer HELICON, flare spectrometer IRIS, amplitude–temporal spectrometer AVS-F, and X-ray spectrometer RPS-1 have been used to analyze the X- and gamma-ray emission from solar flares and for diagnostics of the flaring plasma. The absolute and relative content of various elements (such as potassium, argon, and sulfur) of solar plasma in flares has been determined for the first time with the X-ray spectrometer RESIK. The Solar Cosmic Ray Complex monitored the solar flare effects in the Earth’s environment. The UV emission variations recorded during solar flares in the vicinity of the 120-nm wavelength have been analyzed and the amplitude of relative variations has been determined.     

Precipitation of subrelativistic-energy electrons near the polar boundary of the Earth radiation belt according to the data of measurements on the <Emphasis Type="Italic">Vernov</Emphasis> and <Emphasis Type="Italic">Lomonosov</Emphasis> satellites

The work is devoted to observations of sharp growths of magnetospheric electron fluxes in the vicinity of the polar boundary of the outer radiation belt of the Earth according to the data of measurements on the Vernov and Lomonosov satellites. This precipitation was observed at the high-latitude boundary of the outer radiation belt toward the equator from the isotropization boundary, and can be caused by scattering waves of various physical natures, including electromagnetic and electrostatic waves.     

Designing nonuniform satellite systems for continuous global coverage using equatorial and polar circular orbits

We present a method for designing nonuniform satellite systems for continuous global coverage using a combination of equatorial and near-polar satellite segments in circular orbits. Equations are derived to determine the basic design parameters of the satellite system itself and the conditions of its closure at the joint of near-polar and equatorial segments. We analyze specific features of near-polar and equatorial satellite systems and their advantages and disadvantages compared with existing classes of near-polar phased and kinematically correct satellite systems. We estimate the minimum required number of spacecrafts in satellite systems for a given fold of coverage and present calculated dependences for classes of near-polar phased and equatorial satellite systems with different types of closure. For the class of kinematically correct satellite systems, we analyze the characteristics of systems with a minimum spacecraft flight height and reveal that the number of satellites in the orbital plane depends on the flight height for different folds of coverage. We bring examples of the best near-polar equatorial satellite systems of global coverage for different folds and a class of satellite systems with a fixed number of spacecrafts and orbital planes in them.