C/C—SiC复合材料的制备与性能

采用化学气相渗透（CVI）法和液相浸渍有机物先驱体混合工艺制备了C／C－SiC复合材料，并对复合材料力学性能、抗烧蚀性能和抗氧化性能进行表征。结果表明：制备的C／C－SiC复合材料在基本保证C／C复合材料力学性能的基础上，抗氧化和抗烧蚀性能得以大幅度提高，提出了制备兼具C／C复合材料与陶瓷材料的技术途径。     

C/SiC-W复合材料的制备与表征

采用化学气相渗透(CVI)结合溶液浸渍法制备C/SiC-W多元基复合材料,利用XRD和SEM对材料的物相组成及微观结构进行表征,并对制备过程的反应机理进行初步探讨.结果表明,W在复合材料中成颗粒团聚状,它不仅能渗入到复合材料的纤维束间,还渗入到纤维束内.制得C/SiC-W复合材料的密度为4.1g/cm3,开气孔率为12%.     

Cf/Al复合材料管件的真空液相成型工艺研究

以高模高强碳纤维M40J(6K)增强铝基复合管为研究对象，研究了真空反压液相浸渗工艺中，纤维束丝分散技术、预制件压缩强度提高技术及碳纤维涂层对管件成型及性能的影响。结果表明：SiCp可以起分散作用，有利于浸渍；加入10％的偏磷酸盐的预制件经680℃真空去胶后的压缩性能满足浸渗要求，纤维保持了较好的平直度且分布均匀。C-Al2O3涂层对复合材料的性能有较大影响，经涂层处理后的预制件所制备出的复合材料的强度比未经涂层处理的提高了13％左右。所制备的复合材料的比强度、比模量较高，密度小于2．5g／cm^3。     

基于网络的可重构电火花线切割CAD/CAM系统研究

针时线切割行业的特点，给出了一种切实可行的基于网络的线切割CAD／CAM系统开发方案，该系统分为可重构的客户端软件和可伸缩的服务器端软件两部分。文中对系统的体系结构、客户端软件的重构、工艺数据库以及服务器载荷的平衡、网络流量的控制等相关技术进行了研究和探讨，并对相关技术进行了验证，结果表明开发方案和其中采用的技术是可行的和有效的。     

连续自由流电泳微重力下分离模式蛋白质的研究

以连续自由流电泳的区带电泳模式分离血红蛋白和细胞色素C，比较了不同缓冲液甘油浓度下的分离效果，确定了最终装载在神舟4号飞船上A3—2型电泳仪的电泳分离条件，通过地面和空间实验，初步探讨了微重力对连续自由流电泳分离的影响，并对电泳的分离产物做了多种检测．     

固体冲压发动机喷管用C/C-SiC复合材料

采用"化学气相渗透+先驱体浸渍裂解"(CVI+PIP)混合工艺制备固体冲压发动机用C/C-SiC复合材料喷管内层,综合考查复合材料的微观结构、弯曲性能和抗烧蚀性能以及固冲发动机C/C-SiC喷管内层水压和点火实验。结果表明:复合材料的弯曲强度达到197 MPa,且断裂破坏行为呈现典型的韧性模式;复合材料具有优异的抗氧化烧蚀性能,氧化烧蚀200 s后线烧蚀率仅为0.0063 mm·s-1;研制的C/C-SiC复合材料构件的水压爆破压强为6.5 MPa,表明构件具有良好的整体承载能力;C/C-SiC复合材料喷管内层高温综合性能通过了固体冲压发动机点火实验考核。     

TMS320C6678多核DSP的加载配置和实现方法

程序代码正确的固化加载运行是多核DSP应用的前提和基础.简要介绍了DSP的加载器和加载过程,阐述了多核处理器件的加载配置管理方法.以TI公司的多核DSP TMS320C6678为例,介绍了多核DSP的加载模式和流程,详细阐述了EMIF16的Nor FLASH加载实现方法,可以实现多核DSP软件的正确、可靠加载运行.     

Initial nighttime ionospheric observations with advanced ionospheric probe onboard FORMOSAT-5

FORMOSAT-5 satellite was launched into a sun-synchronous orbit at 720 km altitude with 98.28° inclination on 25 August 2017. The onboard scientific payload, Advanced Ionospheric Probe (AIP) is capable of measuring topside ionospheric ion density, cross-track flow velocities, ion composition and temperature, and electron temperature. Initial observations of nighttime midlatitude ionospheric density and vertical flow velocity variations at 2230 LT sector during a few quiet magnetic days in December 2017 are studied here. Longitudinal density variations in the equatorward edge of midlatitude ionospheric trough (MIT) region are noticed. Accompanied with this density variation, the vertical flow velocities also behave differently. Although the density difference has been stated due to zonal wind effect related to the declination of the geomagnetic field lines, the vertical flow velocity variation seems to play the opposite role. All these density and vertical flow observations in the northern winter hemisphere can only be explained by the longitudinal differences in the diffusion velocity coming down from the protonsphere (plasmasphere). In addition, the hemispheric asymmetry in the vertical flow velocity can also be explained by the interaction between the topside ionosphere and the protonsphere. The observed vertical flow variations near MIT at different longitudes should present a new potential tool for the study of MIT formation.     

Global ionospheric scintillations revealed by GPS radio occultation data with FY3C satellite before midnight during the March 2015 storm

Global observations of S4 amplitude scintillation index by the GPS Occultation Sounder (GNOS) on FengYun-3 C (FY3C) satellite reveal global dynamic patterns of a strong pre-midnight scintillations in F-region of the ionosphere during the St. Patrick’s Day geomagnetic super storm of 17–19 March 2015. The observed strong scintillations mainly occurred in the low latitudes, caused by equatorial plasma bubbles. During the main storm phase (March 17), the scintillations were first triggered in the New Zealand sector near 160°E longitudes, extending beyond 40°S dip latitude. They were also enhanced in the Indian sector, but significantly suppressed in East Asia near 120°E longitude and in Africa around 30°E longitude. During the initial recovery phase (March 18–19), the global scintillations were seldom observed in GNOS data. During the later recovery phase (after March 19), the scintillations recovered to the pre-storm level in Indian, African, and American sectors, but not in East Asian and any of Pacific sectors. These results closely correlate with observations of the density depletion structures by the Communication/Navigation Outage Forecasting System (C/NOFS) satellite, and ground-based instruments. Such consistency indicates reliability of our scintillation sensing approach even in a case-by-case comparison study. The prompt penetration electric field and disturbance dynamo electric field are suggested as the main factors that control the enhancement and inhibition of the scintillations during the storm, respectively.     

A statistical study of C IV regions in 20 Oe-stars

In this paper, using the Gauss-Rotation model (GR model), we analyse the UV C IV resonance lines in the spectra of 20 Oe-stars of different spectral subtypes, in order to detect the structure of C IV region. We study the presence and behavior of absorption clouds and analyse their characteristics. From this analysis we can calculate the values of a group of physical parameters, such as the apparent rotational and radial velocities, the random velocities of the thermal motions of the ions, the Full Width at Half Maximum (FWHM), the optical depth, as well as the absorbed energy and the column density of the independent regions of matter, which produce the main and the satellite clouds of the studied spectral lines. Finally, we present the relations between these physical parameters and the spectral subtypes of the studied stars and we give our results about the structure of the C IV region in their atmosphere.