excess product
3.Firstly, the sample was amidated with excess dibutylamine at room temperature, then the product was separated on Hypersil BDS column(4.0 mm×200 mm,5 μm) with an acetonitrile-water(volume ratio 67∶33)system added 1%(φ) dibutylamine and regulated to pH=6.5 by phosphoric acid as mobile phase and quantitatively detected by UV detector with wavelength at 224 nm.
6.In many years, automobile industry of our province always is at the low-end position of value chain of the international labor division in joint investment with foreign enterprises, general development profit level is not high, competitiveness in production cost and product price are left behind in the world, so we always obtain processing profit instead of excess profit; design and production technology of entire cars and component products are left far behind with international advanced level, development of components is severely lagging from the development of the entire cars, especially transnational companies always control procurement of components with high technical content and added value, so we have to import components with key technology.
