improve on

He is looking to improve on his admittedly modest achievements so far.

迄今为止，他的成就的确不算大，他打算更进一步。

Knotless operation can reduce yarn defects and improve resultant yarn quality on a certain degree.

无接头操作法在一定程度上减低了纱疵,对成纱质量有的改善。

At the same time, to levy enough in time and operate macro-economic control well, levier should plan tax by improving on tax laws and enhancing the management of tax.

同样，征主体为了依法及时征足和发挥收的宏观经济调控职，也需要通过完善法和加强收征管等途径进行征筹划。