fr-number 中文意思是什麼
fr-number
解釋
弗勞德數-
Streptomyces low copy number plasmid scp2 * is also employed for the cloning and recovery of large dna fragment from streptomyces. as scp2 * can accommodate large dna insertions and is efficiently transmissible among its permissive hosts such as s. lividansbut seemed to be unable to replicates in streptomyces sp. fr - 008, it might be a suitable vector for the cloning of the entire fr - 008 pks gene cluster through gene replacement followed by conjugation with 5
Scp2 *可以在變鉛青鏈黴菌等許可宿主內復制並在許可宿主間有效轉移，但似乎不能夠在鏈黴菌fr - 008中復制，因此可能適合於在鏈黴菌fr - 008中通過進行基因置換及隨后的鏈黴菌fr - 008和變鉛青鏈黴菌間的接合過程來克隆完整的fr - 008生物合成基因簇。 -
And, we also have had the relation between the size of the horizontal circulation regions and the fr number around the dike for the flow - deflection method. the results of this study show that, using the method of flow - deflection or " sucking - spouting " water, the flow pattern can be improved, the size of the horizontal circulation regions and the sedimentation volume caused by the horizontal circulation can both be reduced. so, they can be adopted to improve the navigation condition of upper approaching channel of three gorges project, which could guarantee the safety of navigation
通過試驗，得到了以下創新的成果： 1 、不加吸、噴水時，丁壩后的迴流長度約為丁壩長度的8倍； 2 、加吸、噴水可以減小丁壩后的迴流尺度和強度，並得出了有理論根據的吸、噴流量與迴流尺度減小之間的定量關系以及吸、噴流量與丁壩周圍流速梯度之間的定量關系； 3 、加吸、噴水可以減小迴流淤積，並得出了吸、噴流量與淤積量減小之間的定量關系以及迴流尺度減小與淤積量減小之間的定量關系； 4 、加導流板可以減小丁壩后的迴流尺度，並得出了丁壩周圍的水流fr數與迴流尺度減小之間的定量關系。 -
( 2 ) with f varying, there exists a number fr which is about - 1 ( curvature, torsion and dean number have little influence on fr ), when f > fr, the maximum of the axial velocity is near the outside bent and the friction factor ratio increases with f increasing ; when f < fr, the maximum is near the inner side bent and the ratio increases with f decreasing ; when f = fr, the distributions of the axial velocity are similar to those of poiseuille flow and the friction ratio is about 1
（ 2 ）當f變化時，存在確定的數值fr （ fr在- 1左右。曲率、撓率和dean數對fr的影響很小） ，當f fr時，軸向速度最大值偏向外側，摩擦系數比隨f增大而增大；當f fr時，軸向速度最大值偏向內側，摩擦系數比隨f減小而增大；當f = fr時，軸向速度的分佈和poiseuille流近似相同，摩擦系數比約為1 。
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