Purified yntatl trypanosomes were broken by n - tosyl - lysine chloromethyl ketone ( tlck ) and centrifugated by high g to form soluble proteins . the soluble proteins were chromatographed on a de - 52 column . the material in the first peak constituted the purified vsg 用国际命名法命名为yntat1 . 1 、 yntat1 . 2 、 - - - yntat1 . 20 ，从实验结果中未见这20个vats在5只兔体内按照某种特定规律变异，但是其中有15个优势vats在连续感染中多次重复，这印证了某些vats倾向于在感染早期出现的规律( gray1965等) 。
Wavelengths or scales of surface heterogeneity are less than 20km . simulation results show that cbls do reach a quasi - stationary state correspondent to specified surfaces , after a long enough evolution . in this transition process and after that , horizontal statistics , i . e . mean potential temperature and vertical heat - flux , show profiles little differences to those over homogeneous flat surface . main effect of surface heterogeneity is to increase kinetic energy in cbl and the increase concentrates in the direction of surface heterogeneity . the time of cbl spent to reach its first peak of mean kinetic energy , 模拟结果表明，在充分长的时间后，边界层达到一种适合于地面条件的准定常态。这种准定常态和向其过渡的过程中，水平平均的边界层廓线性质，如平均位温廓线垂直热通量廓线等几乎与平坦均匀地面的结果相同，或差异极小。地面非均匀性的主要作用是使边界层动能增大，并以地面非均匀性变化方向的动能增加为主。
