Comparative Study on Super Fine Mesophase Powder and MCMB Used to Manufacture High-Density Isotropic Carbon Bulks

Mesocarbon microbeads （MCMB） and super fine mesophase powder （SFMP） were prepared firstly from a coal tar pitch and then hot-condensed into high-density isotropic carbon （HDIC） bulks under 160 MPa and finally sintered at 1 000 ℃. By analyzing the thermogravimetric behavior of the MCMB and SFMP powders, their volume shrinkage and weight loss during sintering and the bulk density and flexural strengths of their sintered bulks, it was found that the smaller sizes and the richer β-resin contents of SFMP ha）re facilitated formation of sintered bulks with more compact isotropic structure and higher flexural strengths than MCMB. Because of the filling and bonding effects of SFMP on MCMB bulks, addition of SFMP, albeit a little, can greatly increase the flexural strengths of sintered bulks of MCMB. However, adding MCMB, even a slight amount, into SFMP can severely impair the flexural strength of sintered bulks. This might be attributed to both the crack initiation along the boundaries between MCMB and SFMP and the formation of layered texture of MCMB sphere.     

Standing wave drift of hemispherical resonator with quality factor non-uniformity under a ring electrode excitation

Hemispherical Resonator Gyroscope(HRG) is a classical high precision Coriolis Vibration Gyroscope(CVG), which performs attitude estimation of carrier by detecting the precession of standing wave of resonator, thus, the drift of standing wave of resonator has a great influence on the output accuracy of gyroscope, where the quality factor nonuniformity of resonator is one of main error sources. Ring electrode is a classical excitation structure of HRG because the standing wave can precess freely u...     

Overview of the Solar Polar Orbit Telescope Project for Space Weather Mission

The Solar Polar ORbit Telescope (SPORT) project for space weather mission has been under intensive scientific and engineering background studies since it was incorporated into the Chinese Space Science Strategic Pioneer Project in 2011.SPORT is designed to carry a suite of remote-sensing and in-situ instruments to observe Coronal Mass Ejections (CMEs),energetic particles,solar high-latitude magnetism,and the fast solar wind from a polar orbit around the Sun. The first extended view of the polar regions of the Sun and the ecliptic enabled by SPORT will provide a unique opportunity to study CME propagation through the inner heliosphere,and the solar high-latitude magnetism giving rise to eruptions and the fast solar wind.Coordinated observations between SPORT and other spaceborne/ground-based facilities within the International Living With a Star (ILWS) framework can significantly enhance scientific output.SPORT is now competing for official selection and implementation during China's 13th Five-Year Plan period of 2016-2020.      

Main Science Results from Chinese Meridian Project(2014—2015)

The Chinese Meridian Space Weather Monitoring Project (Meridian Project for short) is a ground-based geospace monitoring chain in China. It consists of a chain of 15 ground-based observatories located roughly along 120°E longitude and 30°N latitude. Each observatory is equipped with multiple instruments to measure key parameters such as the baseline and time-varying geomagnetic field, the middle and upper atmosphere and ionosphere from about 20 to 1000km. This project started collecting data in 2012. Here a brief overview of the Chinese Meridian Project is given, and most recent science results mainly in the ionospheric and atmospheric studies are presented.      

Observations from Fengyun Satellites

Fengyun (FY) Satellite has a polar-orbiting series and a geostationary series. Up to now, 7 polar-orbiting (FY-1A/B/C/D and FY-3A/B/C) and 7 geostationary (FY-2A/B/C/D/E/F/G) satellites were launched. FY data has been being intensively applied not only to meteorological monitoring and prediction but also to many other fields regarding ecology, environment, disaster and so on.      

Recent Development and Preliminary Results of Chinese Meridian Project

The Meridian Project is a ground-based network program to monitor solar-terrestrial space environment, which consists of a chain of 15 ground-based observatories located roughly along 120°E longitude and 30°N latitude. The Meridian project started in 2008, and its construction was completed by 2011. The integration and test phase of the Meridian Project conducted in 2011 demonstrated its observation capabilities as expected. The project will be in full operation in 2012. This report gives an overview of the recent development and preliminary results of the Meridian Project since 2010.      

Numerical simulation of flow in swirl injector for power-law fluid

In order to investigate the flow characteristics of swirl injectors for gelled propellants, which actually behaved as non-Newtonian power-law fluid, a swirl axisymmetric model was established to solve Navier-Stokes equations and VOF (volume of fluid) equation, and the power-law constitutive equation was used to describe the rheology characteristics of the gelled propellants. The film thickness and velocity distribution in the swirl injector under different flow conditions were studied numerically. The simulation results show that the increased geometry characteristic parameter of the swirl injector contributes to the decrease of liquid film thickness. The liquid film thickness is almost independent of the pressure drop. The rheologic parameters have great influences on the inner flow of swirl injector: by increasing the fluid consistency index K and power index n, both the axial and the swirl velocities decrease dramatically; higher fluid consistency index K and power index n make the liquid film thickness increase. When the viscosity is large enough, the air core in the injector would vanish.      

Dust Acoustic Wave in Dusty Plasmas With Streaming Ions Under Ultraviolet Irradiation

The reductive perturbation method is applied to investigate the dust acoustic soliton in dusty plasmas with streaming ions under ultraviolet irradiation theoretically and numerically. The self-consistent dust charge variation is taken into account. It is shown that the ultraviolet irradiation can significantly lower the magnitude of the dust negative charge, and ion streaming velocity firstly raise the magnitude of the dust negative charge and then lower it. With the growth of (Ultraviolet) UV photo flux or ion streaming velocity, the phase velocity and width of the solitary waves decrease, whereas its amplitude increases.      

Surface micro-texture on sapphire fabricated by laser ablation trajectory regulation

Fabrication of the surface micro-texture on the C-plane sapphire is undertaken by a355 nm Ultraviolet(UV) pulsed laser. The surface micro-textures of sapphire with different laser scanning line spacing ranging from 10 lm to 100 lm are obtained, where the selection range of scanning line spacing is controlled in the range of the groove width and plasma width to obtain a surface of high Peak-Valley(PV) value. A reasonable processing order is proposed to manufacture different types of surface micro...     

Manipulation of Colloidal Droplets in Space and the Instability of Thermocapillary Convection in Large Prandtl Number Liquid Bridge in Microgravity

In 2016 and 2017, SJ-10 and TG-2 satellites were launched. In this short paper, we report recent progress on the studies of manipulation of colloidal droplets and instability of thermocapillary convection in large Prandtl number liquid bridge that based on the space experiments boarding SJ-10 and TG-2 satellites, separately. It was shown that the colloidal droplets can be successfully formed and manipulated in microgravity through the patterned substrates. In another aspect, the coffee-ring effect was observed at the first time in space. For the studies of the instability of thermocapillary convection in large Prandtl number liquid bridge in microgravity, our experiments in TG-2 broadened the way of such kind of study and abundant experimental results are emerging.