(1)令n=1,得a1=S1=2a1-1,解得a1=1,
当n≥2时,an=Sn-Sn-1=2(an-an-1),
整理,得an=2an-1,
∴an=2n?1.
∵数列{bn}满足b1=1,nbn+1=(n+1)bn,
∴
=bn+1 n+1
,bn n
∴{
}是首项为1的常数列,∴bn n
=1,bn n
∴bn=n.
(2)∵数列{bn}的前n项和为Qn,
∴Qn=1+2+3+…+n=
,n(n+1) 2
∵Tn=Sn+Qn,
∴Tn=2?2n?1?1+
=2n?1+n(n?1) 2
,n(n+1) 2
当n=1时,λT1≥T2,得λ≥3,
当n=2时,λT2≥T3,得λ≥
,13 6
猜想:当λ≥3时,3Tn≥Tn+1.
证明:3Tn?Tn+1=3[2n?1+
]-[2n+1?1+n(n+1) 2
](n+1)(n+2) 2
=2n+n-3≥0.
综上所述,λ存在最小值3,使不等式λTn≥Tn+1成立.