RESUMEN
This paper mainly focuses on the robust stability criteria for uncertain T-S fuzzy systems with time-varying delay by (m,N)-delay-partitioning approach. A modified augmented LKF is established by partitioning the delay in all integral terms. Via taking into account of (i) the relationship between each subinterval and time-varying delay and (ii) the independent upper bounds of the delay derivative in the various delay intervals, some new results on tighter bounding inequalities such as Peng-Park׳s integral inequality and Free-Matrix-based integral inequality are introduced to effectively reduce the enlargement in bounding the derivative of LKF as much as possible, therefore, significant less conservative results can be expected in terms of es and LMIs, which can be solved efficiently with the Matlab LMI toolbox. Furthermore, it is worth mentioning that, when the delay-partitioning number m is fixed, the conservatism is gradually reduced with the increase of another delay-partitioning number N, but without increasing any computing burden. Finally, two numerical examples are included to show that the proposed method is less conservative than existing ones.
RESUMEN
A 1.8kb fragment of lat was obtained from Streptomyces clavuligerus 27064, and replacement plasmid of pXAL1 and pXAL2 were constructed. PXAL1 and pXAL2 were used to disrupt the lat gene by bi-parental conjugation from E. coli to Streptomyces clavuligerus. A Am(r)Thio(S) transformant, named as XAL863, was obtained. The genome of Streptomyces clavuligerus 27064 and XAL863 was analyzed by southern blot technique, and the activity of lysine epsilon-aminotransferase in the two strains was also tested. Both results proved that the lat was disrupted in the XAL863. Streptomyces clavuligerus and XAL863 were cultured in the shaken flask respectively, and the production of clavulanic acid was analyzed by HPLC with the different incubation time interval, and the yield was approximately 1.8 times higher in the XAL863 at their highest production point.
