The technical problems and approval standards for the regional test of soybean varieties in Liaoning Province were discussed. The technical key points for the soybean regional trials were the selection of trial fields...The technical problems and approval standards for the regional test of soybean varieties in Liaoning Province were discussed. The technical key points for the soybean regional trials were the selection of trial fields, preparations in lab be-fore sowing, preparations in regional trial field before sowing, sowing in suitable time and strict with sowing process, field management and survey record, harvest and sampling as wel as lab test and summary. In addition, the approval standards for common varieties and quality varieties for the soybean regional trials in Liaoning were introduced, with the aim to provide accurate and scientific theoretical basis for the approval of soybean varieties.展开更多
As the pump turbine tends to be operated with high head and high rotational speed, the study of stability problems becomes more important. The pump turbine usually works at operating conditions where the guide vanes e...As the pump turbine tends to be operated with high head and high rotational speed, the study of stability problems becomes more important. The pump turbine usually works at operating conditions where the guide vanes experience strong vibrations. However, most traditional studies were carried out based on constant GVO(guide vane opening) simulations. In this work, dynamic analysis on pressure fluctuation in the vaneless region of a pump turbine model was conducted using a dynamic mesh method in turbine mode. 3D unsteady simulations were conducted where GVO was closed and opened by 1° from the initial 18°. Detailed time domain and frequency domain characteristics on pressure fluctuation in the vaneless region under different guide vane rotational states compared with constant GVO simulations were investigated. Results show that, during the guide vanes oscillating process, the low and intermediate frequency components in the vaneless region are significantly different. The amplitudes of pressure fluctuation are higher than those with constant GVO simulations, which agree better with the experimental data. In addition, the pressure fluctuation increases when GVO is opened, and vice versa. It can be concluded that pressure fluctuation in the vaneless region is strongly influenced by the oscillating of the guide vanes.展开更多
基金Supported by the Research Station Program of the National Soybean Industrial Technology R&D System of China(CARS-04)~~
文摘The technical problems and approval standards for the regional test of soybean varieties in Liaoning Province were discussed. The technical key points for the soybean regional trials were the selection of trial fields, preparations in lab be-fore sowing, preparations in regional trial field before sowing, sowing in suitable time and strict with sowing process, field management and survey record, harvest and sampling as wel as lab test and summary. In addition, the approval standards for common varieties and quality varieties for the soybean regional trials in Liaoning were introduced, with the aim to provide accurate and scientific theoretical basis for the approval of soybean varieties.
基金supported by the National Key Technology R&G Program(Project No.2012BAF03B01-X)Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.51121004)
文摘As the pump turbine tends to be operated with high head and high rotational speed, the study of stability problems becomes more important. The pump turbine usually works at operating conditions where the guide vanes experience strong vibrations. However, most traditional studies were carried out based on constant GVO(guide vane opening) simulations. In this work, dynamic analysis on pressure fluctuation in the vaneless region of a pump turbine model was conducted using a dynamic mesh method in turbine mode. 3D unsteady simulations were conducted where GVO was closed and opened by 1° from the initial 18°. Detailed time domain and frequency domain characteristics on pressure fluctuation in the vaneless region under different guide vane rotational states compared with constant GVO simulations were investigated. Results show that, during the guide vanes oscillating process, the low and intermediate frequency components in the vaneless region are significantly different. The amplitudes of pressure fluctuation are higher than those with constant GVO simulations, which agree better with the experimental data. In addition, the pressure fluctuation increases when GVO is opened, and vice versa. It can be concluded that pressure fluctuation in the vaneless region is strongly influenced by the oscillating of the guide vanes.
