神舟六号载人飞船及其技术改进

介绍了我国第二次载人航天飞行试验的目标和主要任务，给出了神舟六号载人飞船的主要任务和技术指标，以及构型与布局、子系统设置与设备配套、飞行方案、发射窗口和飞行轨道等技术状态。概述了神舟五号飞船飞行试验问题归零、飞行任务引起的更改、提高产品可靠性的更改、其他原因引起的更改和工艺流程的变化等部分技术改进。神舟六号载人飞船飞行试验的成功表明，其技术可满足多人多天空间飞行的要求。     

4F富里叶变换透镜系统的三维变换特性

本文从理论和实验上应用4F富里叶变换透镜系统,把三维物场转换为三维象场。象的空间位置和光场振幅的变化与透镜系统的焦距以及物体距焦平面的位置有关。根据4F系统的三维变换特性,本文还讨论了该系统对三维粒子场全息记录、再现的影响。     

一种电离层物理模型及其在F1谷区形成讨论中的应用

在电离层F区考虑了三种中性成分的4种离子(O~+、No~+、N_2~+和O_2~+),从严格的电子和离子密度连续方程出发,由中性风所满足的动力学方程和离子运动方程解出水平中性风,从而得到离子垂直漂移速度,由此建立了一种电离层的物理模式;并用此模式,针对我国中、低纬(116°E,30°N)地区,讨论了光化学作用对F_1层的影响和动力学效应在F层中的作用。着重讨论由水平中性风引起的离子垂直漂移运动对F_1谷区的影响。结果表明:在光化平衡模式下,E区明显形成。在太阳活动低年夏季可产生明显的F_1“凸缘”。但仅靠光化平衡作用不能产生深的F_1谷区,也不能解释F_2层的形成;双极扩散是F_2层形成的主要机制;中性风的因素对E层影响不大,却可以在太阳活动低年夏季产生谷深在0.05—0.1的深F_1谷区。用此模式还计算了F_1谷区日变化,结果表明:中性风影响模式能较好地反映我国中低纬地区F_1谷区变化的地域特征。     

An update global model of hmF2 from values estimated from ionosonde and COSMIC/FORMOSAT-3 radio occultation

In this paper, we present our recent work on developing an updated global model of the ionospheric F2 peak height hmF2 parameter by combining data from the Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC/FORMOSAT-3) radio occultation (RO) measurements and from the extended global ionosonde stations. In particular, 10 Chinese ionosonde stations’ data are newly introduced into this study. The modeling technique used is based on a two-layer empirical orthogonal function (EOF) expansion. Global distributions of hmF2 maps calculated using the newly constructed global model and the one provided by the International Reference Ionosphere model (IRI-ITU-R) are compared with the global distributions of hmF2 obtained by the COSMIC RO measurements and quantitative statistical analysis of the differences between the model results and those of the COSMIC RO measurements is made for the low (2008) and high (2012) solar activity years. The obtained average root-mean-square differences (RMSEs) for our model are 27.7 km (11.1%) and 31.0 km (9.8%), respectively for the years 2008 and 2012, whereas those for the IRI-ITU-R model are 39.9 km (16.9%) and 35.0 km (11.6%), respectively. Comparison of the results calculated both by our model and the IRI-ITU-R model with the digisonde observation is also made. The comparisons show that the newly constructed global hmF2 model can reproduce reasonably well the observations and perform better than IRI-ITU-R model.     

Dynamics of global electron content in 1998–2005 derived from global GPS data and IRI modeling

We analyzed the dynamics of global electron content (GEC) for the period 1998–2005 and compared the estimated GEC with variations of the 10.7-cm solar radio emission and with and with GEC values obtained with IRI-2001. We found a strong resemblance between the curves’ shapes for the experimental and modeled GEC: strong semiannual variations are discernible in these series and both curves tend to increase the absolute GEC value during the period of maximum of solar activity. However, there are some significant distinctions, such as absence of 27-day fluctuations in the series of GEC computed by the IRI-2001. On the contrary, observational GEC reflects well dynamics of solar activity: 27-day variations of GEC are very similar to the ones of the index F10.7, but GEC undergoes a lagging of about of 30–60 h as compared to value of the F10.7 index. The relative amplitude of 27-day variations decreases from 8% at the rising and falling solar activity to 2% at the period of its maximum.     

Evaluation of global modeling of M(3000)F2 and hmF2 based on alternative empirical orthogonal function expansions

Global modeling of M(3000)F2 and hmF2 based on three alternative EOF (empirical orthogonal function) expansion methods is described briefly. Data used for the model construction is the monthly median hourly values of M(3000)F2 from the ionosonde/digisonde stations distributed around the world for the period of 1975–1985 and the hmF2 data of the same period converted from the measured M(3000)F2 based on the strong anti-correlation existing between them. Independent data of a low (1965) and a high (1970) solar activity year are used to validate the three alternative models based on different EOF expansion methods. Comparisons between the modeled results and observed data for both the low (1965) and high (1970) solar activity years showed good agreement for both M(3000)F2 and hmF2 parameters. Statistical analysis on the differences between model values and observed data showed that all the three alternative models (Model A, B and C) based on the different EOF expansion methods have better agreement with the observed data than the models currently used in IRI. All three alternative EOF based models have almost the same accuracy. Discussion on the preference of the three alternative EOF based models is given.     

Estimation of foF2 variations using round-the-world sounding data

An estimation of the F2 ionospheric region critical frequency (foF2) variations using analysis of round-the-world radio sounding data has been made. Experimental data obtained by the Russian chirp-sounders network have been used. For the first time, using experimental data and numerical simulation, the quantitative dependency between the minimum foF2 magnitudes over round-the-world propagation paths and round-the-world maximum usable frequencies has been obtained.     

Validation of B2bot in the NeQuick model during high solar activity at Hainan station

NeQuick ionospheric electron density model, which has been developed to version 2, produces the full electron density profile in the ionosphere. Each part of the profile is modeled using Epstein layer formalism. Simple empirical relations are used to compute the thicknesses of each layer. In order to validate the B2_bot parameter in the NeQuick model during high solar activity, we use the data at Hainan, China (109.1°E, 19.5°N; Geomagnetic coordinates: 178.95°E, 8.1°N), measured with DPS-4, and study the diurnal and seasonal variations of B2_bot, ΔB2 (B2_best − B2_NeQuick 2) and the seasonal median values of B2_best/B2_NeQuick 2 at that region. The results show that, (1) The differences between B2_best and B2_NeQuick 2 have diurnal and seasonal variations. (2) The diurnal variations of B2_NeQuick 2 are smaller than those of B2_best. (3) Generally, except for early morning the experimental values are properly reproduced. (4) Generally, during morning the NeQuick model has an underestimation. The magnitude of underestimation varies with LT and season.     

一种在时域内计算三维翼颤振的方法

使用模态法构造结构模型,研究了在时域内耦合结构模型和气动模型预测三维翼颤振的方法;求解N-S方程计算非定常气动力.Newmark算法简化颤振方程.采用无限平面插值方法耦合结构网格和气动网格;使用弹性系数算法和局部网格重构法重构非结构气动网格,以确保结构方程和气动方程进行耦合求解.AGARD 445.6翼算例检验了计算方法的可行性.     

Solar flux effects on equatorial ionization anomaly and total electron content over Brazil: Observational results versus IRI representations

The F layer critical frequency (foF2) as measured by Digisondes in the equatorial and low latitude locations in Brazil is analyzed to investigate the seasonal and solar flux controls of the intensity of the equatorial ionization anomaly (EIA) in the equinoctial month of March. The analysis also included the total electron content (TEC) as measured by a GPS receiver operated at the EIA crest location. The foF2 data set covered a period of large solar flux variation from 1996 to 2003, while the GPS TEC data was for a period in 2002–2003 when the solar flux parameter F10.7 underwent large variations, permitting in both cases an examination of the solar flux effects on these parameters. The seasonal variation pattern in TEC shows a maximum in equinoctial months and a minimum in June solstice, with similar variations for foF2. The solar flux dependence of the TEC is a maximum during equinoxes, especially for post-sunset TEC values at times when the latitudinal distribution is controlled by the equatorial evening plasma fountain processes. Significant variations with local time are found in the degree of solar flux dependence for both the TEC and EIA. The EIA intensity shows large dependence on F10.7 during post-sunset to midnight hours. These results are discussed in comparison with their corresponding IRI representations.