In fed-batch culture of Klebsiella pneumoniae, 1,3-propanediol production was growth associated, while the by-products, including lactic acid and ethanol, increased sharply as the cells grew slowly. When the fed-batch culture was supplied with a mixture of organic acids including citrate, fumarate and succinate, cell growth and 1,3-propanediol production increased significantly, whereas the by-products, especially lactic acid and ethanol, decreased sharply. High concentrations of PDO and acetate inhibited cell growth and PDO production. To improve the PDO production, repeated fed-batch culture with addition of the organic acid mixture was performed in a 5-l reactor. The fed-batch culture was repeated five times, and the 1,3-propanediol yield and concentration reached above 0.61 mol mol(-1) and 66 g l(-1), respectively, in 20 h for each cycle. Furthermore, the PDO productivity reached above 3.30 g l(-1) h(-1) in each cycle, which was much higher than that of the original fed-batch culture.

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In order to improve the accuracy of diagnosis to satisfy the maintenance of weapon equipment, a kind of expert system (ES) is used in this paper. The system is integrated into neural network (NN) and fuzzy inference. The basic system structure diagrams adopt the frame of expert systems. ES is logic inference part and responsible for symbol processing. The status parameters are described by fuzzy theory and the structure model is built with fuzzy directed graph. The fuzzy logic inference provides an appropriate knowledge representation method to depict fuzzy knowledge. NN is responsible for numerical value calculation. The learning ability of NN can partially or entirely resolve the bottleneck problem of knowledge acquisition. The results indicate the validity and rationality of the model and the method.

A new method for reflecting the Auto cylinder pressure via measurement of ignition current is presented in this paper. It expounds in detail the design thought of system design, transmitter design, implementation of host computer of the system and design of the system software, presents a solution for testing cylinder pressure based on the transmission mode of PCB planar Rogowski coil as transmitter and wireless network, makes improvement to signal conditioning circuit for higher reliability of program and lower R&D cost by the design thought of modular software, which is valuable for guidance and reference in the research and development of similar testing system.

Optical transmission of quartz glass is measured during loading and unloading process，and the stress was kept below their Hugoniot elastic limit. The results show that the quartz glass maintains good transparency for more than 15 μs under loading processes of 18 GPa，then it starts to lose its transparency about 07 μs after unloading，with 30% decrease of transmittance. This phenomenon，which reflects the growth and evolution of failure induced by unloading process in quartz glass，has been explained reasonably by the growth of spherical particles and the scattering model. The results are different from the explanation of liquid-solid phase transition given in literature［J. Chem. Phys. 2004，121 9050］. This paper is significant for studying the transparency of other transparent material.