Abstract: The present invention discloses a multistage variable burning rate solid rocket motor and a forming method. A multi-material composite fiber skeleton structure is embedded inside a propellant in the present invention, so that the original burning rate of the propellant presents multistage changes to achieve the function of multistage thrust. The fiber skeleton structure embedded in the solid rocket motor is formed by additive manufacturing, fixed in a combustion chamber, and then charged at one time to complete the forming of a motor grain. The design can greatly increase the burning rates of the propellants of end-burning and bore-burning motors, and can also conduct multistage adjustment for the burning rates of the motors by changing the fiber skeleton and structure, so as to satisfy the requirements of missile weapon systems for multistage power propulsion. The present invention greatly simplifies the technological production process of the existing single-chamber multi-thrust motor.

Abstract: A catalyst for inducing thermal desorption of organic matter-contaminated soil and a preparation method thereof, which uses a colloidal mixture of ferroferric oxide and ferric chloride as a catalytic active component of thermal desorption, and carbon tetrachloride as a solvent. Based on the mass of solvent, a mass percentage of catalytic active component is 0.1%-15%. Ammonia water is added dropwise to ferric chloride aqueous solution to react in oil bath to generate a ferroferric oxide colloidal solution, then ferric chloride and obtained ferroferric oxide colloidal solution are added to carbon tetrachloride, and mixed solution is continuously stirred in an oil bath to evaporate solvent water to prepare a catalyst with carbon tetrachloride as solvent. Catalyst is environmentally friendly and can induce thermal desorption of organic matters in soil. 100% desorption of chlorobenzene, o-xylene and benzo[A]anthracene can be achieved at 130° C., and energy consumption of thermal desorption is greatly reduced.

Abstract: The present invention provides a catalyst for catalytic reduction of an industrial flue gas SO2 with CO to prepare sulfur, a method for preparing the same and use thereof. A CeO2 nanocarrier is prepared by using a hydrothermal method, La and Y are loaded as active components, pre-sulfurization is conducted with 6% of SO2 and 3% of CO, and finally, the catalyst is prepared. The catalyst has high reactivity and sulfur selectivity and strong stability. The by-product sulfur generated by the reaction is recovered with a solvent CS2, and the solvent CS2 is recovered by using a distillation process. The preparation method is low in cost, causes no secondary pollution and is high in sulfur recovery rate. The problem of low sulfur production in China at present is solved.

Abstract: A catalyst for inducing thermal desorption of organic matter-contaminated soil and a preparation method thereof, which uses a colloidal mixture of ferroferric oxide and ferric chloride as a catalytic active component of thermal desorption, and carbon tetrachloride as a solvent. Based on the mass of solvent, a mass percentage of catalytic active component is 0.1%-15%. Ammonia water is added dropwise to ferric chloride aqueous solution to react in oil bath to generate a ferroferric oxide colloidal solution, then ferric chloride and obtained ferroferric oxide colloidal solution are added to carbon tetrachloride, and mixed solution is continuously stirred in an oil bath to evaporate solvent water to prepare a catalyst with carbon tetrachloride as solvent. Catalyst is environmentally friendly and can induce thermal desorption of organic matters in soil. 100% desorption of chlorobenzene, o-xylene and benzo[A]anthracene can be achieved at 130° C., and energy consumption of thermal desorption is greatly reduced.

Abstract: The present invention provides a catalyst for catalytic reduction of an industrial flue gas SO2 with CO to prepare sulfur, a method for preparing the same and use thereof. A CeO2 nanocarrier is prepared by using a hydrothermal method, La and Y are loaded as active components, pre-sulfurization is conducted with 6% of SO2 and 3% of CO, and finally, the catalyst is prepared. The catalyst has high reactivity and sulfur selectivity and strong stability. The by-product sulfur generated by the reaction is recovered with a solvent CS2, and the solvent CS2 is recovered by using a distillation process. The preparation method is low in cost, causes no secondary pollution and is high in sulfur recovery rate. The problem of low sulfur production in China at present is solved.