一篇science paper中两个句子不太明白 （Vol 307, 1067)
烦请明白人翻译一下，谢谢

1 here we suggest a purely entropic approch to undersatnding the folding of helice that arise from a local and homogeneous interaction with depleting spheres.

什莫是"depleting spheres"

2 In order to maximize the entropy of the colloidal depletants, the two tubes....

还是同一个问题， 什莫是"depletants"