In this paper, the theoretical expressions of wood thermal conductiv ity in the choral and radical direction are derived from the micro-structure of wood by applying some basic principles in physical mechanics. The t...In this paper, the theoretical expressions of wood thermal conductiv ity in the choral and radical direction are derived from the micro-structure of wood by applying some basic principles in physical mechanics. The thermal conduc tivities of about twenty species of trees were calculated by means of the expres sions and compared with its experimental values under the same condition. The av erage relative error is about 5%, so the calculation result is satisfactory.展开更多
We develop a high resolution ground penetrating radar system （LANRCS-GPR） based on the E5071B Vector Network Analyzer （VNA）. This system takes advantage of a wideband and adjustable frequency domain ground penetra...We develop a high resolution ground penetrating radar system （LANRCS-GPR） based on the E5071B Vector Network Analyzer （VNA）. This system takes advantage of a wideband and adjustable frequency domain ground penetrating radar system and adds the characteristics of a network analyzer with ultra-wideband and high precision measurement. It adopts the LAN mode to concatenate system control that reduces construction cost and makes the system easy to expand. The high resolution ground penetrating radar system carries out real time imaging using F-K migration with high calculation efficiency. The experiment results of the system indicate that the LANRCS-GPR system provides high resolution and precision, high signal-to-noise ratio, and great dynamic range. Furthermore, the LANRCS-GPR system is flexible and reliable to operate with easy to expand system functions. The research and development of the LANRCS-GPR provide the theoretical and experimental foundation for future frequency domain ground penetrating radar production and also can serve as an experimental platform with high data gathering precision, enormous information capability, wide application, and convenient operation for electromagnetic wave research and electromagnetic exploration.展开更多
基金Natural Science Foundation of Fujia n Province. Theoretical Research on Wood Thermal Property.
文摘In this paper, the theoretical expressions of wood thermal conductiv ity in the choral and radical direction are derived from the micro-structure of wood by applying some basic principles in physical mechanics. The thermal conduc tivities of about twenty species of trees were calculated by means of the expres sions and compared with its experimental values under the same condition. The av erage relative error is about 5%, so the calculation result is satisfactory.
基金This project was supported by National Natural Science Foundation of china (No.40474042)
文摘We develop a high resolution ground penetrating radar system （LANRCS-GPR） based on the E5071B Vector Network Analyzer （VNA）. This system takes advantage of a wideband and adjustable frequency domain ground penetrating radar system and adds the characteristics of a network analyzer with ultra-wideband and high precision measurement. It adopts the LAN mode to concatenate system control that reduces construction cost and makes the system easy to expand. The high resolution ground penetrating radar system carries out real time imaging using F-K migration with high calculation efficiency. The experiment results of the system indicate that the LANRCS-GPR system provides high resolution and precision, high signal-to-noise ratio, and great dynamic range. Furthermore, the LANRCS-GPR system is flexible and reliable to operate with easy to expand system functions. The research and development of the LANRCS-GPR provide the theoretical and experimental foundation for future frequency domain ground penetrating radar production and also can serve as an experimental platform with high data gathering precision, enormous information capability, wide application, and convenient operation for electromagnetic wave research and electromagnetic exploration.
