Pseudomonas aeruginosa NJ-814, isolated from garden soil, produced an extracellular aminopeptidase that was purified using ammonium sulfate precipitation and ion exchange chromatography. The purity was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the Mr value of the enzyme was estimated to be 55 kDa. The purified enzyme shows maximum activity at pH 9.0 and 80 °C. It exhibits high thermo-stability. Half of the activity can remain after incubation at 80 °C for 119 min. It is stable within pH range of 7.5-10.5. It is strongly activated by Co(2+) and inhibited by Fe(2+) , Cu(2+) , Ni(2+) , Zn(2+) , and ethylene diamine tetraacetic acid (EDTA). The specificity of the enzyme was investigated. Within several aminoacyl-p-nitroanilines (AA-pNA), Lys-pNA is proven to be the optimal substrate. The Michaelis-Menten constant (Km ) of the enzyme for Lys-pNA and Leu-pNA were 2.32 and 9.41 mM, respectively. Peptide map fingerprinting shows that the sequence of the enzyme is highly similar to aminopeptidase Y from P. aeruginosa 18A. It can be speculated that this enzyme is a Zn(2+) -dependent enzyme and contains two zinc ions in its active site.

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Sequential control is to use binary information digital technology of automatic control mode. Realization sequential control most has three kinds representative method: sequence table method, expression method and ladder diagram method. In this paper, we analyzed polymerizer coating technological process and Sequence Control Flow, then make use of CENTUM CS-3000s sequence table to realize the polymerizer coating completely automatic sequential control. The practice proved that it improved polymerizer coating effect, raised the equipment utilization rate and the PVC quality. it had the widespread application promotion value.

The higher equipment reliability can not only ensure the device running continuously, reduce all kinds of consumption, but reduce the accidents occurring because of the equipment defect. In this paper, an optimization strategy for ensuring the reliability of large automatic equipments using the lowest maintenance cost to improve the production efficiency of petrochemical enterprises was put forward. Several maintenance strategies are proposed, in which the reliability of large automatic equipment and the maintenance and repair cost are considerate overall. Reliability maintenance strategies of automatic equipment in the petrochemical industry are research detailed. And strategies of reliable maintenance and the implementation of reliable maintenance are studied.