The vibration of a Francis turbine is analyzed with the additional quality matrix method based on fluid-structure coupling （FSC）. Firstly, the vibration frequency and mode of blade and runner in air and water are ca...The vibration of a Francis turbine is analyzed with the additional quality matrix method based on fluid-structure coupling （FSC）. Firstly, the vibration frequency and mode of blade and runner in air and water are calculated. Secondly, the influences to runner frequency domain by large flow, small flow and design flow working conditions are compared. Finally the influences to runner modes by centrifugal forces under three rotating speeds of 400 r/rain, 500 r/min and 600 r/rain are compared. The centrifugal force and small flow working condition have greatly influence on the vibration of small runner. With the increase of centrifugal force, the vibration frequency of the runner is sharply increased. Some order frequencies are even close to the runner natural frequency in the air. Because the low frequency vibration will severely damage the stability of the turbine, low frequency vibration of units should be avoided as soon as possible.展开更多
Acetosyringone （AS） has great influences on Agrobacterium-mediated genetic transformation. In order to improve the transformation frequency of waxy maize, in this study, shoot tips and immature embryo-derived callus...Acetosyringone （AS） has great influences on Agrobacterium-mediated genetic transformation. In order to improve the transformation frequency of waxy maize, in this study, shoot tips and immature embryo-derived callus of Lainongnuo 38 were collected as receptor materials, to compare the effects of pH in suspension medium, addition modes and concentrations of acetosyringone on genetic transformation of waxy maize. Results showed that adding 2 μl of 150 μmol/L AS in the wound with suspension medimn at pH 5.2 can significantly improve the transformation frequency of shoot tips of waxy maize; in genetic transformation of maize callus, adding 5 mg/L AS in infection solution can significantly improve the percentage of resistant callus.展开更多
An additional sensitivity penalty of burst mode receivers due to the extinction ratio is analyzed considering the specific transmitter control in Ethernet PON. For an extinction ratio of 6dB, a penalty of 8dB occurs a...An additional sensitivity penalty of burst mode receivers due to the extinction ratio is analyzed considering the specific transmitter control in Ethernet PON. For an extinction ratio of 6dB, a penalty of 8dB occurs additionally.展开更多
基金Outstanding Youth Science Fund Subsidization of Sichuan Province, China (No. 05204033).
文摘The vibration of a Francis turbine is analyzed with the additional quality matrix method based on fluid-structure coupling （FSC）. Firstly, the vibration frequency and mode of blade and runner in air and water are calculated. Secondly, the influences to runner frequency domain by large flow, small flow and design flow working conditions are compared. Finally the influences to runner modes by centrifugal forces under three rotating speeds of 400 r/rain, 500 r/min and 600 r/rain are compared. The centrifugal force and small flow working condition have greatly influence on the vibration of small runner. With the increase of centrifugal force, the vibration frequency of the runner is sharply increased. Some order frequencies are even close to the runner natural frequency in the air. Because the low frequency vibration will severely damage the stability of the turbine, low frequency vibration of units should be avoided as soon as possible.
基金Supported by National Natural Science Foundation of China(31201218)National Science and Technology Project of "Twelfth Five Year" Plan of China(2011BAD35B01)+3 种基金Taishan Scholars Program of Shandong Province(Crop Cultivation and Breeding)Basic Research Program of Science and Technology Project of Qingdao City[12-1-4-5-(11)-jch]Starting Fund for High-level Personnel of Qingdao Agricultural University(No.630740)Shandong Key Laboratory of Maize Breeding and Cultivation Techniques
文摘Acetosyringone （AS） has great influences on Agrobacterium-mediated genetic transformation. In order to improve the transformation frequency of waxy maize, in this study, shoot tips and immature embryo-derived callus of Lainongnuo 38 were collected as receptor materials, to compare the effects of pH in suspension medium, addition modes and concentrations of acetosyringone on genetic transformation of waxy maize. Results showed that adding 2 μl of 150 μmol/L AS in the wound with suspension medimn at pH 5.2 can significantly improve the transformation frequency of shoot tips of waxy maize; in genetic transformation of maize callus, adding 5 mg/L AS in infection solution can significantly improve the percentage of resistant callus.
文摘An additional sensitivity penalty of burst mode receivers due to the extinction ratio is analyzed considering the specific transmitter control in Ethernet PON. For an extinction ratio of 6dB, a penalty of 8dB occurs additionally.
