Cracking and Mechanical Properties of Airport Concrete Pavement with Fiber and Expansive Agent

Polypropylene fiber and expansive agent are used in airport concrete to improve its shrinkage cracking resistance and mechanical properties. The concrete specimens with amount content of polypropylene fiber or expansive agent or both of them are prepared. The morphology of specimens is observed by scanning electron microscope, the time when the first crack occurred is recorded through slap test, and the mechanical properties such as compressive strength and impact energies of concrete are measured. The results show that polypropylene fiber in concrete can reduce the shrinkage and delay the first crack, improve the impact resistance obviously, and improve the compressive strength slightly. Expansive agent can compensate the shrinkage and reduce cracks of concrete pavement markedly, and improve the mechanical properties of concrete pavement slightly. The study provides recommendations for cracking control of airport concrete pavement in the future.     

《中国儒教史》反思：中国文化宗教论－－兼与李申先生商榷

李申的《中国儒教史》其思想方法是对中国化进行彻底的宗教化，与任继愈的“儒教是教说”一样承诺了否定中国化的价值取向，并且比“儒教是教说”有过之而无不及。中国化宗教论是对中国化的歪曲和否定，应该对其反思批判、正本清源。     

Basic performance of BeiDou-2 navigation satellite system used in LEO satellites precise orbit determination

The visibility for low earth orbit（LEO） satellites provided by the BeiDou-2 system is analyzed and compared with the global positioning system（GPS）. In addition, the spaceborne receivers＇ observations are simulated by the BeiDou satellites broadcast ephemeris and LEO satellites orbits. The precise orbit determination（POD） results show that the along-track component accuracy is much better over the service area than the non-service area, while the accuracy of the other two directions keeps at the same level over different areas. However, the 3-dimensional（3D） accuracy over the two areas shows almost no difference. Only taking into consideration the observation noise and navigation satellite ephemeris errors, the 3D accuracy of the POD is about30 cm. As for the precise relative orbit determination（PROD）, the 3D accuracy is much better over the eastern hemisphere than that of the western hemisphere. The baseline length accuracy is 3.4 mm over the service area, and it is still better than 1 cm over the non-service area. This paper demonstrates that the BeiDou regional constellation could provide global service to LEO satellites for the POD and the PROD. Finally, the benefit of geostationary earth orbit（GEO） satellites is illustrated for POD.     

Max＋PlusⅡ结合Matlab对数字系统进行联合设计与仿真

介绍一种Max PlusⅡ结合Matlab对数字系统进行联合设计与仿真的方法，这种方法通过Matlab来完成数字系统的原理方案仿真、模块设计和系统必要参数获取；通过比较Max Plus与Matlab的仿真结果差异来实现硬件模块的功能验证、模块之间时序关系的调整和系统功能的直观验证；最后以高速数字解调器载波恢复部分的设计为例讨论了该方法的具体应用。     

The study of a plasma jet injected by an on-board plasma thruster

The injected plasma jet-ionosphere interaction features were studied in experiments carried out on board two METEOR satellites. The injected plasma jet propagation depends considerably on jet injection pitch-angle. The impactless jet spreading took place without considerable interaction with the ionosphere plasma, when injected along the magnetic field. By injection across the magnetic field very effective plasma jet-ionosphere plasma and the Earth's magnetic field interaction was observed. Plasma jet injection provoked the generation of electromagnetic fields near the satellite.     

提高非英语专业学生英语写作能力的实验研究

本文采用定性研究和定量研究相结合的方式在两平行班实施实验,探究进行英语周记写作训练能否有效提高大学非英语专业学生的英语写作自信心和写作水平。教学实验数据表明,在经过一学期的英语周记写作训练之后,实验组学生的英语写作自信心和写作水平均明显优于对照组,在统计学上具有显著意义。     

航空修理系统转型建设与跨越式发展时期人才培训工作探讨

从空军航空修理系统转型建设和人才发展战略的角度全面阐述创新培训工作机制。     

眼镜蛇机动分析及相关运动参数重构估算

详细地介绍了“眼镜蛇”机动的运动特点、完成条件及其动作过程和要点，根据飞机运动特点建立了相应的数学模型。阐述了在测量失真的情况下，如何用工程计算方法确定飞机的重要运动参数及其气动力、力矩参数等。并以Su-27飞机为例进行了计算验证。结果表明，该方法结果可靠，能满足工程分析要求，可以推广用于一般的短时间内完成的动态剧烈机动。     

Results of ZARNITZA-2, a rocket experiment on artificial electron beam injection in the ionosphere

The rocket experiment ZARNITZA-2 on artificial electron beam injection in the ionosphere was carried out on September 11, 1975. Great attention was paid to the study of phenomena occurring in the near-rocket region. The results of the experiment are discussed in terms of a beam plasma discharge.     

一种RS码变换域译码算法及其并行流水结构

本文提出了ＲＳ系统码的一种变换域译码算法，设计和分析了该算法的并行流水结构。该算法不用求错误位置多项式的根和错误值，运算结构规则，适合于ＶＬＳＩ实现。