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... "RNA Helicases" Without Duplex Unwinding . Science 304: 730-734 (2004)

... RNA begins when the two DNA strands for a gene unwind and separate. A protein present in the nucleus, called RNA polymerase...

一輪直徑3cm，有一4m 的細繩繞在其圓周上。輪由靜止開始轉動，並有一定角加速度2.0 rad/s^2。細繩會在幾秒後鬆開： 輪之圓周長=πD=(3/100)π=0.03π(m) 細繩長= 4m →繞了4/(0.03π)圈=[4/(0.03π)]*(2π)弳=(800/3)弳 即角度=800/3弳 θ=(ω0)t+1/2*α*t^2 800/3=0+0.5*2* t^2 t= 16.33 (s...