mezzo staccato

[胡海鹏 - Hu Haipeng]

Hello,
  I ever asked 3 signs, and 2 (portato and martellato) have been solved. Now I just finished my second orchestral work and am revising. The articulation makes my head big. There are many mezzo-staccatoed notes, but I just used portato. I think it's not correct, because it's just a line. In my theory book, a mezzo staccato is a line plus staccato. But I don't know whether c4-.-- does this correctly. Are these two signs work as one in this circumstance? Or are they far from each other?

Regards
Haipeng