设\(\{a_{n}\}\)是首项为\(1\)的等比数列,数列\(\{b_{n}\}\)满足\(b_{n}=\dfrac{na_{n}}{3}\),已知\(a_{1}\),\(3a_{2}\),\(9a_{3}\)成等差数列.
\((1)\)求\(\{a_{n}\}\)和\(\{b_{n}\}\)的通项公式;
\((2)\)记\(S_{n}\)和\(T_{n}\)分别为\(\{a_{n}\}\)和\(\{b_{n}\}\)的前\(n\)项和\(.\)证明:\(T_{n}< \dfrac {S_{n}}{2}.\)