
如图,三棱柱\(ABC-A_{1}B_{1}C_{1}\)中,\(BC\)垂直于正方形\(A_{1}ACC_{1}\)所在平面,\(AC=2\),\(BC=1\),\(D\)为\(AC\)中点,\(E\)为线段\(BC_{1}\)上的一点\((\)端点除外\()\),平面\(AB_{1}E\)与\(BD\)交于点\(F\)
\((\)Ⅰ\()\)若\(E\)不是\(BC_{1}\)的中点,求证:\(AB_{1}/\!/EF\);
\((\)Ⅱ\()\)若\(E\)是\(BC_{1}\)的中点,求\(AE\)与平面\(BC_{1}D\)所成角的正弦值;
\((\)Ⅲ\()\)在线段\(BC_{1}\)上是否存在点\(E\),使得\(A_{1}E⊥CE\),若存在,求出\( \dfrac {BE}{EC_{1}}\)的值,若不存在,请说明理由.