The United Nations Basic Space Science Initiative (UNBSSI)

Since 1991 the United Nations Office for Outer Space Affairs has been conducting a series of workshops on basic space science under its United Nations Programme on Space Applications. Up to 2004 the workshops focussed on capacity building efforts in basic space science, in particular for the benefit of developing countries. From 2005 onwards the workshops and their related activities contributed to the celebration of the International Heliophysical Year 2007. Together these activities and workshops constitute the United Nations Basic Space Science Initiative of the United Nations Office for Outer Space Affairs. This paper reflects on the achievements and outcomes of the Initiative and informs about considerations for its future evolution.     

砷化镓异质外延薄膜的近红外光致发光研究

本文通过在硅衬底上用ＭＯＣＶＤ方法生长的砷化镓外延薄膜的变激发强度的近红外光致发光，研究了在液氮温度下峰值为１．１３与１．０４ｅＶ两个发光带的发光特性。     

非线性飞行稳定性研究的新综合方法

本文提出“分歧和突变理论-时间历程-龙格库塔灵敏度分析”的综合方法,用其研究作为非线性系统的飞机稳定性。该方法利用分歧理论来确定飞机的全局稳定性,并由平衡面找出应予检验的平衡点,对这些平衡点,计算状态参数的时间历程,由此确定飞机运动的性质。最后,利用龙格-库塔灵敏度分析方法来研究动稳定性随时间的变化,由此可以解析地求得任意瞬间影响飞行稳定性的空气动力项,结构项及组合项。 利用上述方法所得到的有关稳定性的信息是全面的,它对飞机的操稳设计有重要参考价值。     

CCSDS-RS(255,223)码高速译码器的硬件实现研究

研究了空间通信用高速Reed-Solomon(255,223)码硬判决译码器的FPGA实现方法,提出一种新的纠错算法实现结构以最大程度提高译码器性能。设计中采用RiBM算法求解关键方程,并通过应用高速比特并行乘法器以及流水线和并行处理方法提高译码通过率。综合和测试验证结果显示,该译码器译码通过速率为1.7Gbit/s,译码延迟为296个时钟周期,优于目前同类型的RS译码器性能指标。     

模式识别与模糊三值逻辑推理探讨

本文介绍了模式识别的概念与基本方法,形象思维与模式识别的关系和模糊逻辑与模糊推理,提出模糊三值逻辑的推理方法,旨在进一步探讨模式识别的方法和模糊逻辑推理理论,并附应用实例。     

卫星振动压环优化设计

针对压环压不紧和易变形的缺陷进行了有限元分析,提出了一种振动压环优化设计方法。通过对优化前后数据的比较分析,探讨了提高压环抗变形能力和增加预紧力的途径。实际应用表明,卫星的一阶频率较压环优化前有明显提高,且没有再出现压环变形的情况。     

Amateur observations of solar eclipses and derivation of scientific data

This work presents the educational approach of using total solar eclipse occurrences as a scientific process learning aid. The work reviews the basic scientific aims and experiments included in the observational programs “Total solar eclipse 1999 and 2006” (Stoev, A., Kiskinova, N., Muglova, P. et al. Complex observational programme of the Yuri Gagarin Public Astronomical Observatory and STIL, BAS, Stara Zagora Department for the August 11, 1999 total solar eclipse, in: Total Solar Eclipse 1999 – Observational Programmes and Coordination, Proceedings, Recol, Haskovo, pp. 133–137, 1999a (in Bulgarian); Stoeva, P.V., Stoev, A.D., Kostadinov, I.N. et al. Solar Corona and Atmospheric Effects during the March 29, 2006 Total Solar Eclipse, in: 11th International Science Conference SOLAR–Terrestrial Influences, Sofia, November 24–25, pp. 69–72, 2005).     

Detection of regolith buried water stream channels on Mars with the help of synthetic aperture radar

A major theme in the study of Mars is the search for evidence that water was present in the past or is present today, either at or below the surface. Biological life is connected to water. Hence much research is focused on the detection of water stream channels, which in the past flowed on Mars. In these areas, the petrified remains of the former life on Mars may be found. These channels may be under the regolith layer; however, the radio wave penetrating ability allows for the detection of these channels under the regolith.     

Plant mineral nutrition,gas exchange and photosynthesis in space: A review

Successful growth and development of higher plants in space rely on adequate availability and uptake of water and nutrients, and efficient energy distribution through photosynthesis and gas exchange. In the present review, literature has been reviewed to assemble the relevant knowledge within space plant research for future planetary missions. Focus has been on fractional gravity, space radiation, magnetic fields and ultimately a combined effect of these factors on gas exchange, photosynthesis and transport of water and solutes.     

关于英语专业本科毕业论文选题的若干思考

通过问卷调查发现,英语专业本科毕业论文的选题存在过大、过小、与英语关系不大等问题。为此,文章提出了如下建议:需要把英语本科毕业论文选题融合到各个阶段的专业课堂教学上,在三年级第二学期给学生开毕业论文写作指导课并安排指导教师。若这些都能得到实施,必将有力提高英语专业本科毕业论文选题的质量。