improve upon
4.Formation mechanism of the internal stress arised from such factors as solidification, structure transformation, heat conduction, manufacturing process, inclusion and so on has been described, and it has been stated that controlling and relieving of the internal stress are the basic way to stabilize and improve upon quality of the grinding ball made of the high chromium white cast iron.
7.In order to meet the requirements of modern health residence to improve the indoor air quality based upon advantages and disadvantages analysis of traditional open ways of windows a new safe energy saving window?casement turnover window is proposed which is well accepted by construction enterprises.
9.Through an introduction to the classification and genesis of interlanguage fossilization, this paper mainly analyzes the effects of negative transfer of mother tongue upon fossilization from three layers of phonology, vocabulary and syntax and points out that fossilization can block foreign language learners to further improve their foreign language proficiency.
10.This paper expatiate upon applying the principle of using finite difference method in siumlating three dimensional stable point electrical source field, and brings forward grid dissection, differential format and super relaxation iterative evaluation method which can save EMS memory, and improve operation speed.

