多路传输数据总线监控器的设计

介绍一种用于航空电子综合化系统的1553B总线监控器的设计.讨论了总线监控器的结构、功能及相应的软件设计.     

Effects of heavy particle irradiation and diet on object recognition memory in rats

On long-duration missions to other planets astronauts will be exposed to types and doses of radiation that are not experienced in low earth orbit. Previous research using a ground-based model for exposure to cosmic rays has shown that exposure to heavy particles, such as ⁵⁶Fe, disrupts spatial learning and memory measured using the Morris water maze. Maintaining rats on diets containing antioxidant phytochemicals for 2 weeks prior to irradiation ameliorated this deficit. The present experiments were designed to determine: (1) the generality of the particle-induced disruption of memory by examining the effects of exposure to ⁵⁶Fe particles on object recognition memory; and (2) whether maintaining rats on these antioxidant diets for 2 weeks prior to irradiation would also ameliorate any potential deficit. The results showed that exposure to low doses of ⁵⁶Fe particles does disrupt recognition memory and that maintaining rats on antioxidant diets containing blueberry and strawberry extract for only 2 weeks was effective in ameliorating the disruptive effects of irradiation. The results are discussed in terms of the mechanisms by which exposure to these particles may produce effects on neurocognitive performance.     

Transient outburst mechanisms in Supergiant Fast X-ray Transients

The recent discovery of a new class of recurrent and fast X-ray transient sources, the Supergiant Fast X-ray Transients, poses interesting questions on the possible mechanisms responsible for their transient X-ray emission. The association with blue supergiants, the spectral properties similar to those of accreting pulsars and the detection, in a few cases, of X-ray pulsations, confirm that these transients are High Mass X-ray Binaries. I review the different mechanisms proposed to explain their transient outbursts and the link to persistent wind accretors. I discuss the different models in light of the new observational results coming from an on-going monitoring campaign of four Supergiant Fast X-ray Transients with Swift.     

An inversion approach for lunar regolith layer thickness using optical albedo data and microwave emission simulation

An approach to inversion of the lunar regolith layer thickness by using multi-channel brightness temperature observation in passive microwave remote sensing is developed. To first make simulation of brightness temperature from the lunar layered media, the lunar regolith layer thickness (d) is proposed being constructed by available lunar DEM (digital elevation mapping) and on site measurements. The physical temperature distribution (T) over the lunar surface is also empirically assumed as a monotonic function of the latitude. Optical albedo of the lunar nearside from the telescopic observation is employed to construct the spatial distribution of the FeO+TiO₂ content (S) in the lunar regolith layer. A statistic relationship between the DEM and S of the lunar nearside is further extended to construction of S of the lunar farside. Thus, the dielectric permittivity (ε) of global lunar regolith layer can then be determined. Based on all these conditions (d,T,ε), brightness temperature of the lunar regolith layer in passive microwave remote sensing, which is planned for China's Chang-E lunar project, is numerically simulated by a parallel layering model using the strong fluctuation theory of random media.Then, taking these simulations with random noise as observations, an inversion method of the lunar regolith layer thickness is developed by using three- or two-channels brightness temperatures. When the S is low, and the four channels brightness temperatures in China's Chang-E project are well distinguishable, the regolith layer thickness and physical temperature of the underlying lunar rock media can be inverted by the three-channels approach. When the S becomes high that the brightness temperature at high frequency channels such as 19.35, 37 GHz are saturated, the regolith layer thickness is alternatively inverted only by the two-channels approach.Numerical simulation and inversion approach in this paper make an evaluation of the performance for lunar passive microwave remote sensing, and for future data calibration and validation.     

CCD相机模／数变换位数的分析

模数变换是CCD遥感相机成像链路中的一个关键环节,对这一过程进行深入分析和优化设计将有助于提高CCD相机的整体性能。该文通过建模和仿真分析了不同的模数变换量化位数和不同量化方案对系统信噪比的影响。     

基于MCMC的PLP未来强度的Bayesian预测分析

在无信息先验分布下，将Gibbs抽样与Metropolis-Hastings算法相结合的方法应用于幂律过程的未来强度的Bayesian预测。该预测方法能将时间截尾数据和失效截尾数据统一分析，并给出在未来某一时刻处强度函数的MCMC样本，利用该样本可以方便地获得关于未来某一时处刻强度函数及其函数的各种后验分析。一个经典工程数值算例说明了预测方法的可行性、合理性与有效性。     

大学生相对过度教育现象的原因及对策分析

针对目前大学生现存的相对过度教育问题,从高等教育结构盲目争上"高层次"、大学生所学专业与市场需求不匹配、大学生区域就业供给与就业需求不匹配和大学生个体理论知识与实践能力不匹配四个方面,对大学生现存相对过度教育的原因进行了分析,并提出了解决对策。     

“簇形”课程体系在高职网络专业教学改革中的实践

文章就"簇形"课程体系在长沙航院网络专业教学改革中的实践进行了归纳和总结,为高职网络专业建设和发展提供了一些新的想法和思路。     

校企合作共建民航特色实训基地的探索与实践

通过校企合作共建实训基地的优势分析,探讨利用合作办学资源、促进实训建设,校企合作共建实训基地需要解决的问题,总结我院实训基地建设的一些成功经验,以及阐明今后努力的方向。