  Given a closed connected manifold smoothly immersed in a complete noncompact
Riemannian manifold with nonnegative sectional curvature, we estimate the
intrinsic diameter of the submanifold in terms of its mean curvature field
integral. On the other hand, for a compact convex surface with boundary
smoothly immersed in a complete noncompact Riemannian manifold with nonnegative
sectional curvature, we can estimate its intrinsic diameter in terms of its
mean curvature field integral and the length of its boundary. These results are
supplements of previous work of Topping, Wu-Zheng and Paeng.
