As for the characteristics of combustibility of deterrent propellant with large web size which is used in large-caliber gun and interior ballistic performance, the combustion characteristics of deterrent propellant ar...As for the characteristics of combustibility of deterrent propellant with large web size which is used in large-caliber gun and interior ballistic performance, the combustion characteristics of deterrent propellant are obtained by using closed-bomb experiments. The combustion law of deterrent propellant and the classic interior ballistic model of composite charge are given. By simulation and analysis the results of the artillery firing test, the burning rate variation law and the interior ballistics simulation parameters of propellant A are determined, and the burning rate relationship between propellant A and propellant B obtained from closed-bomb, then the ballistic performance of propellant B is predicted. The results show that the predicted results are in good agreement with the experimental results. The study shows that the burning rate law of deterrent propellant with large web size can be obtained by closed-bomb experiment. Using the method provided in this paper can accurately predict the interior ballistic performance and provide an important basis for improving the accuracy of interior ballistic calculation.展开更多
The effects of semiochemicals extracted from 63 species of plants, on peach aphid (Myzus per-sicae) and mustard aphid (Lipaphis erysimi), were studied in laboratory. The deterrent rate, reproduction deterrent index an...The effects of semiochemicals extracted from 63 species of plants, on peach aphid (Myzus per-sicae) and mustard aphid (Lipaphis erysimi), were studied in laboratory. The deterrent rate, reproduction deterrent index and the interferential index of population control (IIPC) was used to evaluate the efficiency of semiochemicals on population control of the two target aphids. The results showed that the extracts of 34 species of common plants have noticeable effect on both aphid populations, especially, Xanthium sibiricum Petr. Et Widd. and Syngonium podophyllum Schott. These plant extracts could be used to construct the plant pro-tectant to protect crops.展开更多
文摘As for the characteristics of combustibility of deterrent propellant with large web size which is used in large-caliber gun and interior ballistic performance, the combustion characteristics of deterrent propellant are obtained by using closed-bomb experiments. The combustion law of deterrent propellant and the classic interior ballistic model of composite charge are given. By simulation and analysis the results of the artillery firing test, the burning rate variation law and the interior ballistics simulation parameters of propellant A are determined, and the burning rate relationship between propellant A and propellant B obtained from closed-bomb, then the ballistic performance of propellant B is predicted. The results show that the predicted results are in good agreement with the experimental results. The study shows that the burning rate law of deterrent propellant with large web size can be obtained by closed-bomb experiment. Using the method provided in this paper can accurately predict the interior ballistic performance and provide an important basis for improving the accuracy of interior ballistic calculation.
文摘The effects of semiochemicals extracted from 63 species of plants, on peach aphid (Myzus per-sicae) and mustard aphid (Lipaphis erysimi), were studied in laboratory. The deterrent rate, reproduction deterrent index and the interferential index of population control (IIPC) was used to evaluate the efficiency of semiochemicals on population control of the two target aphids. The results showed that the extracts of 34 species of common plants have noticeable effect on both aphid populations, especially, Xanthium sibiricum Petr. Et Widd. and Syngonium podophyllum Schott. These plant extracts could be used to construct the plant pro-tectant to protect crops.