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ABSTRACTTeramethylpyrazine (TMP) is a pyrazine alkaloid with a variety of pharmacological effects and widely used in clinical practice. In this study, Monascusstrain M-3 with high TMP and low citrinin productions was screened from red yeast rice collected from different areas of Fujian province in China. Monascusstrain M-3 was further identified through molecular biological methods based on the sequencing of different gene regions. Results showed that primer set of β-tubulin-F/β-tubulin-R targeting the β-tubulin gene was more suitable for the identification of Monascusstrain M-3. Based on comparative analysis of the results obtained by different primer sets, Monacusstrain M-3 was finally identified as Monascus purpureus. Then, the composition of culture medium and liquid state fermentation conditions of Monacusstrain M-3 were optimized by single-factor experiment and central composite design of response surface methodology, with the purpose of optimizing the TMP productions. The optimum composition of culture medium and liquid state fermentation conditions are as follows: starch 5.1%, peptone 3.51%, Mg2SO40.1%, NaNO30.2%, KH2PO40.25%, fermentation temperature of 28.23 °C, fermentation time of 9 d, shaker speed of 180 r/min, inoculum size of 7.21% and loading volume of 100 mL/250 mL triangular flask. Under the optimum composition of culture medium and liquid state fermentation conditions, the TMP production of Monacusstrain M-3 can reach 13.49 µg/mL. This study is expected to provide a new approach of TMP production through biosynthesis by Monascusstrain, and promote the further development of functional foods or medicines from Monascusfermentation products.

A model for optimally evaluating grid short-circuit current limitation measures is proposed. Based on the fuzzy comprehensive evaluation model, a comprehensive evaluation system is introduced to consider the limiting effect and economy of the limiting measures configure program, also the program's impact on system security is involved. A judgment matrix is constructed to determine the weights of different system layers. With fuzzy behavior indices and membership function being led into, the evaluation of configuration program is given. Taking Gansu power grid for example, the feasibility and practicality of the proposed model are verified by simulation results.

When crude oil contains wax and hydrate depositions, thermal management is needed to built up to prevent these deposition formation. Thermal insulation pipe is the common measure. Laying thermal insulation pipe is a complex operation due to their multi-layer structure and heavier weight. In this paper, mechanical analysis for thermal insulation pipe laid by S-lay is carried out. Large deformation theory is applied to establish S-lay model. Equivalent stiffness theory is used to solve the complicated structure. Numerical simulation is done to investigate the effect of controlling parameters to the pipe configuration. Numerical results show that the tension is the main controlling parameter during pipelay.