The IMPACT Solar Wind Electron Analyzer (SWEA)

SWEA, the solar wind electron analyzers that are part of the IMPACT in situ investigation for the STEREO mission, are described. They are identical on each of the two spacecraft. Both are designed to provide detailed measurements of interplanetary electron distribution functions in the energy range 1～3000 eV and in a 120°×360° solid angle sector. This energy range covers the core or thermal solar wind plasma electrons, and the suprathermal halo electrons including the field-aligned heat flux or strahl used to diagnose the interplanetary magnetic field topology. The potential of each analyzer will be varied in order to maintain their energy resolution for spacecraft potentials comparable to the solar wind thermal electron energies. Calibrations have been performed that show the performance of the devices are in good agreement with calculations and will allow precise diagnostics of all of the interplanetary electron populations at the two STEREO spacecraft locations.     

Neutral Atmospheres

This paper summarizes the understanding of aeronomy of neutral atmospheres in the solar system, discussing most planets as well as Saturn’s moon Titan and comets. The thermal structure and energy balance is compared, highlighting the principal reasons for discrepancies amongst the atmospheres, a combination of atmospheric composition, heliocentric distance and other external energy sources not common to all. The composition of atmospheres is discussed in terms of vertical structure, chemistry and evolution. The final section compares dynamics in the upper atmospheres of most planets and highlights the importance of vertical dynamical coupling as well as magnetospheric forcing in auroral regions, where present. It is shown that a first order understanding of neutral atmospheres has emerged over the past decades, thanks to the combined effects of spacecraft and Earth-based observations as well as advances in theoretical modeling capabilities. Key gaps in our understanding are highlighted which ultimately call for a more comprehensive programme of observation and laboratory measurements.     

复材机身制造的自动化流水线工艺过程

AeroSuite给出了一个飞行器制造过程有效管理整个产品制造流程的解决方案。它包括FiberSIM复材工艺软件、SyncroFIT机身设计制造装配软件、对于首件鉴定过程的流程化的质量规划模块(QPE)。     

PARAMETER ANALYSIS ON CIRCULATION CONTROLLED CIRCULAR CYLINDER FOR NOTARTM TAIL BOOM

Lift on circulation control （CC） circular cylinder is calculated via numerical simulations based on 2D real- izable k-e epsilon viscous model and compared with experimental data. The simulation result shows an acceptable agreement with tested data. With the proved grid and simulation method, series of simulations are conducted to study the effect of parameters on lift. Single slotted tail booms under different clown wash velocities are optimized with the principle of generating maximum total moment around the main rotor shaft with same total power con- sumption. The results show that larger jet flow velocity, or smaller blow angle, or larger diameter of the cross section can help generating larger lift while enhancing the attachment of both the jet flow and down wash flow. Multiple slotted tail boom is better because it increases lift with same total slot width, and can increase lift by in- creasing total slot width without causing separation, also it helps generating high steady lift at a big rank of slot at- tack angles. To mount a guide vane （GV） at the exit of the slot, or shape the upper slot wall like a smooth-GV, or design the slot with an edge fillet is not recommended because it reduces the velocity of both the jet flow and the upstream of the attached downwash flow. Compared with other shapes of the slots, arcs-profiled slot performs better because of larger jet flow velocity and smaller blow angle. In order to generate the largest moment with same total power consumed by the entire NOTARTM system, total width of the slots and slot attack angle should be optimized according to velocity of down wash flow.     

Occurrence of equatorial plasma bubbles over Kolhapur

This paper reports the nightglow observations of OI 630.0 nm emissions, made by using all sky imager operating at low latitude station Kolhapur (16.8°N, 74.2°E and dip lat. 10.6°N) during high sunspot number years of 24th solar cycle. The images are analyzed to study the nocturnal, seasonal and solar activity dependence occurrence of plasma bubbles. We observed EPBs in images regularly during a limited period 19:30 to 02:30 LT and reach maximum probability of occurrence at 22:30 LT. The observation pattern of EPBs shows nearly no occurrence during the month of May and it maximizes during the period October–April. The equinox and solstice seasonal variations in the occurrence of plasma bubbles show nearly equal and large differences, respectively, between years of 2010–11 and 2011–12.     

A new global version of M(3000)F2 prediction model based on artificial neural networks

A new version of global empirical model for the ionospheric propagation factor, M(3000)F2 prediction is presented. Artificial neural network (ANN) technique was employed by considering the relevant geophysical input parameters which are known to influence the M(3000)F2 parameter. This new version is an update to the previous neural network based M(3000)F2 global model developed by Oyeyemi et al. (2007), and aims to address the inadequacy of the International Reference Ionosphere (IRI) M(3000)F2 model (the International Radio Consultative Committee (CCIR) M(3000)F2 model). The M(3000)F2 has been found to be relatively inaccurate in representing the diurnal structure of the low latitude region and the equatorial ionosphere. In particular, the existing hmF2 IRI model is unable to reproduce the sharp post-sunset drop in M(3000)F2 values, which correspond to a sharp post-sunset peak in the peak height of the F2 layer, hmF2. Data from 80 ionospheric stations globally, including a good number of stations in the low latitude region were considered for this work. M(3000)F2 hourly values from 1987 to 2008, spanning all periods of low and high solar activity were used for model development and verification process. The ability of the new model to predict the M(3000)F2 parameter especially in the low latitude and equatorial regions, which is known to be problematic for the existing IRI model is demonstrated.     

Method for the prediction of the effective dose equivalent to the crew of the International Space Station

This paper describes a methodology for assessing the pre-mission exposure of space crew aboard the International Space Station (ISS) in terms of an effective dose equivalent. In this approach, the PHITS Monte Carlo code was used to assess the particle transport of galactic cosmic radiation (GCR) and trapped radiation for solar maximum and minimum conditions through an aluminum shield thickness. From these predicted spectra, and using fluence-to-dose conversion factors, a scaling ratio of the effective dose equivalent rate to the ICRU ambient dose equivalent rate at a 10 mm depth was determined. Only contributions from secondary neutrons, protons, and alpha particles were considered in this analysis.     

On the universality of asymptotic limits in the theory of field line diffusion and perpendicular transport of energetic particles

We discuss the random walk of magnetic field lines in astrophysical plasmas. Based on the standard theory of field line diffusion we show that there are two asymptotic limits. In these limits field line wandering is universal because in both regimes the field line diffusion coefficient depends only on fundamental length scales and absolute magnetic field strengths. As examples we discuss the field line diffusion coefficient for different prominent turbulence models namely the slab model, the two-dimensional model, and the Goldreich–Sridhar model. We show that the field line diffusion coefficient for the latter model agrees with the results obtained for slab and two-dimensional turbulence in limiting cases. We also discuss the transport of energetic particles perpendicular with respect to the mean magnetic field. Based on the unified nonlinear transport theory we consider again asymptotic limits. It is shown that one can identify four different regimes in which the transport is again universal. In all four cases perpendicular transport only depends on fundamental length scales of turbulence, magnetic field values, and the parallel diffusion coefficient.     

Signatures of strong geomagnetic storms in the equatorial latitude

Ionosonde data from two equatorial stations in the African sector have been used to study the signatures of four strong geomagnetic storms on the height – electron density profiles of the equatorial ionosphere with the objective of investigating the effects and extent of the effects on the three layers of the equatorial ionosphere. The results showed that strong geomagnetic storms produced effects of varying degrees on the three layers of the ionosphere. Effect of strong geomagnetic storms on the lower layers of the equatorial ionosphere can be significant when compared with effect at the F2-layer. Fluctuations in the height of ionization within the E-layer were as much as 0% to +20.7% compared to −12.5% to +8.3% for the F2-layer. The 2007 version of the International Reference Ionosphere, IRI-07 storm-time model reproduced responses at the E-layer but overestimated the observed storm profiles for the F1- and F2-layers.