摘要：A predominance area diagram for the Zr-Si-C-O system at 1773 K was plotted according to correlative thermodynamic data. β-SiC/ZrO2 composites were prepared based on the phase diagram by carbothermal reduction of zircon （ZrSiO4） in argon atmosphere. Zircon and carbon black were mixed according to the C/ZrSiO4 mass ratio of 0.2, and with 0, 1wt% and 2wt% extra addition of La2O3. Phase evolution of the mixture was investigated at 1723-1803 K by X-ray powder diffraction, and the microstructure of the product prepared at 1803 K for 4 h was examined by scanning electronic microscope. The results show that the decomposition of ZrSiO4 and the formation of β-SIC can be promoted by increasing the heating temperature and adding La2O3. The β-SiC/ZrO2 composites can be prepared at 1803 K for 4 h in a mixture of zircon, carbon black and La2O3, and the contents of β-SIC and m-ZrO2 in the product sample with 2wt% La2O3 reach the highest values of 10.8wt% and 89.2wt%, respectively. The crystal size of the products is about 200 nm.

摘要：This paper presents a new supercritical carbon dioxide(SCO_(2))cannon based on the carbon dioxide(CO_(2))’s thermodynamic cycle under constant ***,Virial equation and NIST database are applied to formulate SCO_(2)’s property and analyze the thermodynamic cycle,which is aimed to get the optimization equation using the cannon’s exit velocity as objective *** the cannon’s structural parameters,such as diaphragm thickness and barrel length,and CO_(2)’s filling mass,are ***,the flow field and velocity’s change during the launch process is performed with *** field test,the ultra-high pressure sensor and ultra-high speed camera are used to measure the pressure distribution along the barrel’s axial direction and the projectile’s exit velocity under different *** results show that all the performance indexes meet the design *** innovative SCO_(2)cannon in this paper has obvious advantages such as high safety,low cost and fast loading,which can be applied in many situations such as disaster relief,peacekeeping and ***,the unique energy storage method and thermodynamic design ensure its subsequent development.

摘要：The present work investigates the influence of ambient temperature on the steady-state off-design thermodynamic performance of a chemical looping combustion(CLC) combined cycle.A sensitivity analysis of the CLC reactor system was conducted,which shows that the parameters that influence the temperatures of the CLC reactors most are the flow rate and temperature of air entering the air *** the ambient temperature variation,three off-design control strategies have been assumed and compared:1) without any Inlet Guide Vane(IGV) control,2) IGV control to maintain air reactor temperature and 3) IGV control to maintain constant fuel reactor temperature,aside from fuel flow rate *** indicate that,compared with the conventional combined cycle,due to the requirement of pressure balance at outlet of the two CLC reactors,CLC combined cycle shows completely different off-design thermodynamic characteristics regardless of the control strategy *** the first control strategy,temperatures of the two CLC reactors both rise obviously as ambient temperature *** control adopted by the second and the third strategy has the effect to maintain one of the two reactors' temperatures at design condition when ambient temperature is above design *** with the second strategy,the third would induce more severe decrease of efficiency and output power of the CLC combined cycle.