As an innovative propulsion technique, combustion mechanism of laser-augmented chemical propulsion has still to be ascertained. Benefiting from high nitrogen content and thermal stability, 5-aminotetrazole is a suitab...As an innovative propulsion technique, combustion mechanism of laser-augmented chemical propulsion has still to be ascertained. Benefiting from high nitrogen content and thermal stability, 5-aminotetrazole is a suitable ingredient for LACP. Under a flowing nitrogen environment, two kinds of unique burning surfaces were observed to occur for 5-ATZ, used as a single reacting propellant ingredient with the addition of carbon, under laser ablation. Both surfaces are hollow structures and differ by the possible presence of edges. Using micro computed tomography, the 3D perspective structures of both surfaces were revealed. Resorting to various characterization methods, a unified formation mechanism for both surfaces is proposed. This mechanism specifically applies to laser ablation, but could be crucial to common burning mechanisms in LACP.展开更多
As an innovative propulsion technique, laser augmented chemical propulsion(LACP) seems superior to the traditional ones. However, the corresponding combustion theories have still to be ascertained for LACP. Burning ra...As an innovative propulsion technique, laser augmented chemical propulsion(LACP) seems superior to the traditional ones. However, the corresponding combustion theories have still to be ascertained for LACP. Burning rate of 5-aminotetrazole(5-ATZ) propellant has been studied by testing pressed samples under different combustor pressures and laser powers. Based on micro computed tomography(Micro CT),an advanced thickness-over-time(TOT) method to characterize the regression of the produced nonplanar burning surface is established. Because of a shell structure covering the combustion surface,the burning rate of the implemented 5-ATZ propellant is not constant during laser ablation. Resorting to functional fitting, a new law of non-constant burning including the effect of the observed unique burning surface structures is proposed. Accordingly, applicable combustion conditions of 5-ATZ based propellants have been preliminarily speculated for future research activities.展开更多
Reactions of CdX2（X=NO3-, ClO4-） with Hatza （atza=5-aminotetrazole-1-acetato anion） and 2,2′-bipyridine （2,2′-bipy） or 1,10-phenanthroline （1,10-phen） in a methanol/aqueous solution produced a set of new Cd...Reactions of CdX2（X=NO3-, ClO4-） with Hatza （atza=5-aminotetrazole-1-acetato anion） and 2,2′-bipyridine （2,2′-bipy） or 1,10-phenanthroline （1,10-phen） in a methanol/aqueous solution produced a set of new Cd（Ⅱ） coordination polymers, {[Cd（atza）（H2O）（2,2′-bipy）]ClO4}n （1）, {[Cd（atza）（H2O）（1,10-phen）]ClO4 }n （2）, {[Cd（atza）（H2O）（2,2′-bipy）]NO3}n （3） and {[Cd（atza）2 （1,10-phen）]·0.5H2O}n （4）. Single-crystal X-ray diffraction analysis reveals that each Cd（Ⅱ） ion has a distorted octahedral coordination geometry in 1-4, and the Cd（Ⅱ） ion centers are connected through the tridentate atza bridging ligands to form a 2D layer （1-3） or ID chain （4） structure. The fluorescent properties of 2 and 4 are also discussed.展开更多
基金supported by the Shanghai Aerospace Science & Technology Innovation Fund (Grant No. SAST201363)the Fundamental Research Funds for the Central Universities (Grant No. 30919012102 in part)。
文摘As an innovative propulsion technique, combustion mechanism of laser-augmented chemical propulsion has still to be ascertained. Benefiting from high nitrogen content and thermal stability, 5-aminotetrazole is a suitable ingredient for LACP. Under a flowing nitrogen environment, two kinds of unique burning surfaces were observed to occur for 5-ATZ, used as a single reacting propellant ingredient with the addition of carbon, under laser ablation. Both surfaces are hollow structures and differ by the possible presence of edges. Using micro computed tomography, the 3D perspective structures of both surfaces were revealed. Resorting to various characterization methods, a unified formation mechanism for both surfaces is proposed. This mechanism specifically applies to laser ablation, but could be crucial to common burning mechanisms in LACP.
基金supported by the Shanghai Aerospace Science & Technology Innovation Fund (grant No. SAST201363)the Fundamental Research Funds for the Central Universities (grant No. 30919012102 in part)。
文摘As an innovative propulsion technique, laser augmented chemical propulsion(LACP) seems superior to the traditional ones. However, the corresponding combustion theories have still to be ascertained for LACP. Burning rate of 5-aminotetrazole(5-ATZ) propellant has been studied by testing pressed samples under different combustor pressures and laser powers. Based on micro computed tomography(Micro CT),an advanced thickness-over-time(TOT) method to characterize the regression of the produced nonplanar burning surface is established. Because of a shell structure covering the combustion surface,the burning rate of the implemented 5-ATZ propellant is not constant during laser ablation. Resorting to functional fitting, a new law of non-constant burning including the effect of the observed unique burning surface structures is proposed. Accordingly, applicable combustion conditions of 5-ATZ based propellants have been preliminarily speculated for future research activities.
基金supported by the Foundation of Suzhou Science and Technology of Jiangsu Province(SYN201015)Key Laboratory of Advanced Functional Materials of Jiangsu Province of China (No.10KFJJ002)
文摘Reactions of CdX2（X=NO3-, ClO4-） with Hatza （atza=5-aminotetrazole-1-acetato anion） and 2,2′-bipyridine （2,2′-bipy） or 1,10-phenanthroline （1,10-phen） in a methanol/aqueous solution produced a set of new Cd（Ⅱ） coordination polymers, {[Cd（atza）（H2O）（2,2′-bipy）]ClO4}n （1）, {[Cd（atza）（H2O）（1,10-phen）]ClO4 }n （2）, {[Cd（atza）（H2O）（2,2′-bipy）]NO3}n （3） and {[Cd（atza）2 （1,10-phen）]·0.5H2O}n （4）. Single-crystal X-ray diffraction analysis reveals that each Cd（Ⅱ） ion has a distorted octahedral coordination geometry in 1-4, and the Cd（Ⅱ） ion centers are connected through the tridentate atza bridging ligands to form a 2D layer （1-3） or ID chain （4） structure. The fluorescent properties of 2 and 4 are also discussed.
