New multifrequency measurements of the spectrum of the cosmic background radiation

New measurements of the Cosmic Background Radiation temperature at 12 cm, 6.3 cm, 3 cm, 0.9 cm and 0.3 cm have made in July 1982 from the White Mountain High Altitude Research Station. The results are presented and the existence of spectral distortions discussed.     

Current collection through the transport of electrons across magnetic field lines

Collection of electrons by a long conducting cylinder in a flowing plasma is studied by means of numerical simulations. The plasma flow simulates the relative motion between a spacecraft and plasma. The sheath structures and the levels of electron current collections for the cases with and without an ambient magnetic field ( ) are studied. It is found that for the flow perpendicular to the magnetic field, the current is considerably enhanced depending on the relative drift velocity. In the case of a non-zero magnetic field perpendicular to the cylinder axis, the potential structure is a two-dimensional double layer with dimensions L L_|, where L and L_| are the dimensions perpendicular and parallel to , respectively. L is found to be the current limiting radius given by the Parker-Murphy model. For the flow along , the electron current is found to be smaller than that for the flow perpendicular to . This is explained in terms of the potential structures.     

Observation of fundamental magnetoplasma emissions excited in magnetosphere by modulated electron beams

There were several cases when modulated electron beam had been injected from APEX satellite into an otherwise unmodified ionospheric plasma. The beams were formed from 2 μs pulses repeated at a rate of 40kHz. Injections took place in the altitude range 400–1100km over Europe. The onboard receiver connected to the dipole antenna swept the frequency interval 1–10 MHz in 1 sec. Due to a relatively narrow receiver bandwidth (15 kHz), moderate frequency step (50 kHz), slow changes of f_n and f_c (local electron plasma and gyro frequencies) fine structure of excited emissions was detected. In many cases, a very prominent doublet could be convincingly identified as a (f_n,f_u=sqrt(f_n^*f_n+f_c^*f_c)) band, with f_n practically equal to the local plasma frequency in the unperturbed ionosphere. Determination of plasma frequency is of prime importance in analysis of complex structures composed from various harmonics f_n,f_c,f_u. Complexity is manifested as coalescing of various harmonics with maxima shifted from nominal frequencies or splitting them into components due to mixing of local and propagation effects. Despite the existence of strong emissions on frequencies characteristic for the unperturbed ionosphere, very strong broadcasting transmissions are frequently cut off, even when the beam is directed upward. Most typical spectra are discussed.     

Theory of physical libration of the Moon with the liquid core: Forced librations

For a two-layer model of the Moon that consists of a solid nonspherical mantle and an ellipsoidal homogeneous liquid core, a theory of forced librations under the effect of gravitational Earth’s moments has been developed. The motion of the Moon over its orbit has been described by the high-accuracy theory of DE/LE-4 orbital motion. Tables have been constructed that present forced librations of the Moon caused by the second harmonic of its force function, in the neighborhood of its motion according to the generalized Cassini laws. Disturbances of the first-order with respect to dynamic compressions of the Moon and its core are obtained in analytical form for Andoyer variables and Poincare variables and for the projection of the angular velocity vector of Moon’s mantle rotation and the Poincare coordinate system (relative to which core’s liquid accomplishes simple motion) on its major central axes of inertia, as well as for the classical variables in the Moon libration theory, etc. Constructed tables of the forced librations theory give the amplitudes and periods of librations and combinations of arguments of the orbital motion theory that correspond to libration parameters. The interpretation of basic variations has been given and a comparison with the previous theories has been carried out, in particular with the modern empirical theory constructed based on the laser observation data.     

A technique of shaping the barrel-type parts

In this paper, a new technique for shaping the thin-walled barrel-type parts is presented.     

Two magnetars: SGR 1627–41 and 1E 1547–5408

We describe the results obtained with Target of Opportunity observations of the galactic sources SGR 1627–41 and 1E 1547–5408. These two transients show several similarities supporting the interpretation of Anomalous X-ray Pulsars and Soft Gamma-ray Repeaters as a single class of strongly magnetized neutron stars.     

An approach to forming the design performance of the attitude control system for small spacecraft

The elements for various types of attitude control systems used in a number of small spacecraft are considered. An approach for assessment of such system effectiveness based on design requirements for spacecraft purpose and restriction in accuracy, mass and energy is proposed.     

磁浮飞行风洞试验技术及应用需求分析

随着高速、超高速轨道交通的快速发展,需要发展新型的风洞设备,实现风洞性能和试验能力的突破.磁浮飞行风洞是利用真空管道列车概念结合动模型试验技术提出的一种新概念风洞设备,可以构建出更加接近真实状态的测试环境.本文从磁浮飞行风洞基本概念、国内外研究现状及发展趋势、试验技术、应用需求等几个方面开展论述.首先论述了国内外传统风洞和动模型设备的现状及发展趋势,指出了发展磁浮飞行风洞的必要性;其次,重点对磁浮飞行风洞需要发展的试验技术进行了分析;最后,对磁浮飞行风洞在超高速轨道交通及其他领域的应用需求进行了展望.     

Approximate analytical solutions of stability problems for skew plates under combined loading

The known analytical solutions of the linearized stability problems for rectangular hinged plates under the combined loading are generalized to the similar problems for skew plates, the deformation mechanics of which is described by the equations of the classical theory formed in the oblique Cartesian coordinates.