An optimum PN guidance law for maneuvering target is developed using optimal control theory.By estimating the target position and setting the cost function,the guidance law can be deduced even without knowing the miss...An optimum PN guidance law for maneuvering target is developed using optimal control theory.By estimating the target position and setting the cost function,the guidance law can be deduced even without knowing the missile lateral acceleration.Since the quadratic cost function can make a compromise between the miss distance and the control constraint,the optimum guidance law obtained is more general.Also,introduced line of sight rate as the input,a practical form of this guidance law is derived.The simulation results show the effectiveness of the guidance laws.展开更多
Ammonium aluminum sulfate hydroxide[NH4Al（SO4）2·12H2O], the precursor of Al2O3, was prepared with the method of sintering, leaching and adjusting the pH value by using fly ash and ammonium sulfate as raw materi...Ammonium aluminum sulfate hydroxide[NH4Al（SO4）2·12H2O], the precursor of Al2O3, was prepared with the method of sintering, leaching and adjusting the pH value by using fly ash and ammonium sulfate as raw materials.High-purity alumina was prepared by calcining NH4Al（SO4）2·12H2O.The effects of the temperature and time of sintering, molar ratio of（NH4）2SO4 vs the Al2O3 in fly ash and the grain size of fly ash on the extraction efficiency of Al2O3 from fly ash were studied.The efficiency of Al2O3 extraction could reach 95.6 percent under the optimum conditions.The purity of the Al2O3 from calcining NH4Al（SO4）2·12H2O that was refined by recrystallization was higher than 99.9 percent.展开更多
文摘An optimum PN guidance law for maneuvering target is developed using optimal control theory.By estimating the target position and setting the cost function,the guidance law can be deduced even without knowing the missile lateral acceleration.Since the quadratic cost function can make a compromise between the miss distance and the control constraint,the optimum guidance law obtained is more general.Also,introduced line of sight rate as the input,a practical form of this guidance law is derived.The simulation results show the effectiveness of the guidance laws.
文摘Ammonium aluminum sulfate hydroxide[NH4Al（SO4）2·12H2O], the precursor of Al2O3, was prepared with the method of sintering, leaching and adjusting the pH value by using fly ash and ammonium sulfate as raw materials.High-purity alumina was prepared by calcining NH4Al（SO4）2·12H2O.The effects of the temperature and time of sintering, molar ratio of（NH4）2SO4 vs the Al2O3 in fly ash and the grain size of fly ash on the extraction efficiency of Al2O3 from fly ash were studied.The efficiency of Al2O3 extraction could reach 95.6 percent under the optimum conditions.The purity of the Al2O3 from calcining NH4Al（SO4）2·12H2O that was refined by recrystallization was higher than 99.9 percent.
