The surface layer of beryllium, specimen, has been strengthened by ion implantation. Its microhardness was measured. The hardness of surface layer has been calculated from the microhardness. The experimental data of t...The surface layer of beryllium, specimen, has been strengthened by ion implantation. Its microhardness was measured. The hardness of surface layer has been calculated from the microhardness. The experimental data of the wear rate indirectly Confirmed the reasonableness of the result of calculation. It is shown that the hardness of the surface layer strengthened, by ion implantation is nine times higher than that of beryllium itself. The relation between hardness and implantation dose was analysed and the best dose was obtained.展开更多
It has been known that the error of measuring acoustic veloicities of thin sediment layers by the well-known T2-X2 approach is usually untolerable, and that this approach is unavailable in the case where sea-bed is ha...It has been known that the error of measuring acoustic veloicities of thin sediment layers by the well-known T2-X2 approach is usually untolerable, and that this approach is unavailable in the case where sea-bed is hard because no echo from any subsurface below sea-bottom can be received. Therefore applying the ray-parameter method to thin layers and the refraction method to hard layers need to be considered in an acoustic velocity measurement system composed of a sound source and a towed hydrophone streamer. Some problems of practical importance about the applications of the two methods, such as echo-data processing procedures and error estimations in measuring acoustic veloicities, are discussed, and the effectiveness of theoretical analyses has been verified through computer simulations.展开更多
基金This project was suportod by Reijing Zhongguancun Associated Center of Analysis and Measurement
文摘The surface layer of beryllium, specimen, has been strengthened by ion implantation. Its microhardness was measured. The hardness of surface layer has been calculated from the microhardness. The experimental data of the wear rate indirectly Confirmed the reasonableness of the result of calculation. It is shown that the hardness of the surface layer strengthened, by ion implantation is nine times higher than that of beryllium itself. The relation between hardness and implantation dose was analysed and the best dose was obtained.
文摘It has been known that the error of measuring acoustic veloicities of thin sediment layers by the well-known T2-X2 approach is usually untolerable, and that this approach is unavailable in the case where sea-bed is hard because no echo from any subsurface below sea-bottom can be received. Therefore applying the ray-parameter method to thin layers and the refraction method to hard layers need to be considered in an acoustic velocity measurement system composed of a sound source and a towed hydrophone streamer. Some problems of practical importance about the applications of the two methods, such as echo-data processing procedures and error estimations in measuring acoustic veloicities, are discussed, and the effectiveness of theoretical analyses has been verified through computer simulations.
