Studies on the thermal properties of four petroleum pitches for spinning and A240 pitch after concocting Were made by thermal gravimetric analysis (TGA) , thermomechanical analysis (TMA) and differential scanning calorimetry (DSC) . Relative thermal stability, vitrification transformation temperature (Tg) and relationships between specific heat and temperature of the five pitches were investigated. Analysis and comparison were also made between different pitches.
The flow curve and apparent viscosity curve as well as viscosity-tem-perature curve of both pitches were determined at RET (30, 50℃) by XLY-Ⅱ capillary rheometer made in china The quality number n and viscous flow activation energy En at constant shearing stress were calculated.
Based on the principle of formation of conjugate tooth contour, the equations of the cam's pitch curve are derived.
The continuity and symmetry of the cam's pitch curve are also analyzed.
The satellite passes chosen for the detailed analysis and modeling lay approximately along the cusp/cleft band from afternoon till prenoon MLT sectors, thus emphasizing the pitch-angle dispersion role with respect to the dispersion due to convection.
Some conclusions about the regime of pitch-angular diffusion into the loss cone are made.
It is assumed that in such a cascade each i-th system (group) of profiles has its own pitch ti (i=1, 2,?, s) and constant phase shift αi of the oscillations between neighboring profiles.
According to coal mixing principle, the inert substances and binders may be added to highly volatile bituminous coal to improve coal quality, thus enhancing coke quality. After much research into thermal plasticity of Taozhuang coal and gaoqiao coal with additives, it has been proved that the former can be made into standard casting coke with the addition of≤10% powder coke and a small quantity of soft pitch while the latter can not.
In this paper , identification of the phase composition of micro-sphorical particae of uraniferous lignite ash was performed by means of four methods , i.e. , the liquid nuclear emulsion microradio-graphy , X-ray diffraction analysis with Debye camera , electron-ns probe analysis of microrange composition , and a microscope-viewe. It has been proved that the spherical particle exists in the form of U1-xO2 , and Fe3O4
In the paper, the spinning parameters of pitches from petroleum residues for manufacturing carbon fiber is investigated. The effects of the spinning temperature, pressure, speed and the pitch's structures and properties to spinning quality are discussed. The method of choosing the best spinning temperature with controlling melt viscosity at about 10 Pa·s, and the ability of enhancing the pitch's spinnability with raising spinning pressure are suggested.