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To study the genes regulating the synthesis of sugar esters in tobacco, transcriptome sequencing analysis was performed on tobacco glandular hair cells and bundle sheath cells, and RT-qPCR was used for verification. The results showed that 11 962 differentially expressed genes were obtained, of which 5145 were up-regulated and 6817 were down-regulated. GO annotation of differentially expressed genes showed that the up-regulated genes mainly included biological processes (2265), molecular functions (1169), and cellular components (363), with a total of 3793 GO terms. Based on the assignment of KEGG pathway, the sequence was mapped to 122 metabolic pathways. Glycolysis/gluconeogenesis, starch and sucrose metabolism, phenylpropanoid biosynthesis related to glycoester synthesis were highly enriched, and acyl sugar pathway in glandular hairs was significantly up-regulated. By comparing with the tobacco reference genome, 12 up-regulated acyltransferase genes were identified in glandular hair cells. RT-qPCR results showed that the expression of 11 genes was higher than that of the control. The expression of gene 63826, gene 16194 and gene 37511 increased by 195.79 times, 166.23 times and 132.65 times, respectively. The above 11 genes may be involved in regulating the synthesis of sugar esters in glandular hair cells, providing a basis for further verification of gene function. [ABSTRACT FROM AUTHOR]

Selenium enriched passion fruit seed oil was prepared by supercritical CO2 extraction method with Selenium enriched passion fruit seed as raw material. Based on single factor experiment, RSM-CCD ( response surface curve-central composite design) was used to explore the effects of temperature, pressure, static extraction time, dynamic extraction time and CO2 flow rate on the extraction rate of Selenium enriched passion fruit seed oil. And the physical and chemical properties, fatty acid content and antioxidant activity of selenium-rich passionfruit seed oil extracted by supercritical CO2 extraction and Soxhlet extraction were investigated. The results showed that optimal process parameters of supercritical CO2 extraction for oil from Selenium enriched passion seed was found to be extraction temperature of 50 °C,extraction pressure of 34 MPa, static extraction of 109 min,dynamic extraction of 97 min, CO2 flow rate of 1.0 L/min. Under this condition, the actual Selenium enriched passion seed oil was clear light yellow liquid, and the yield was 72. 33%. The content of unsaturated fatty acids extracted by supercritical CO2 extraction was 80. 11%, which was slightly higher than that extracted by soxhlet extraction (78.71%); Acid value, peroxide value, oxidation resistance and other properties also showed that the quality of oil extracted by supercritical CO2 extraction was better than that extracted by Soxhlet extraction. [ABSTRACT FROM AUTHOR]

In order to solve the harmonic suppression failure and harmonic surge in workshop distribution system caused by the fault of Active Power Filter (APF) bridge arm, a model predictive fault-tolerant control strategy was proposed. By analyzing the working principle of APF fault-tolerant transformation topology, the relationship of voltage vector transformation after fault-tolerant was revealed, and the prediction model of harmonic compensation current was established. A fast harmonic detection method based on the second-order generalized integral orthogonal generator (SOGI) was designed, and the harmonic compensation current output by SOGI was used as the reference instruction of the predictive control. According to the current predictive model and the reference instruction, in the rhombus voltage vector set of the fault tolerant APF, the switching state satisfying the minimum cost function was selected to carry out model predictive control and harmonic compensation. Experiments results verifed that, in the condition of the bridge arm fault, the proposed control strategy could work continuously and suppress harmonic current. The total harmonic distortion(THD) of the power distribution line is reduced from 9. 91% to 4. 87%, which verified that the proposed method can improve the reliability and fault tolerant capability of APF equipment in the cigarette factory. [ABSTRACT FROM AUTHOR]

In the three-phase four-wire power distribution system of modern cigarette workshops, the zero-sequence current causes the midpoint voltage fluctuation on the DC side, which affects the harmonic control effect of active power filter (APF). To solve this problem, a model predictive reconstructed space voltage vector control strategy based on neutral point clamped (NPC) three-level APF was proposed. The APF harmonic control hierarchy analysis framework was constructed, the three performance indicators of midpoint voltage balance, zero sequence current compensation and space voltage vector utilization were designed, and the performance of various voltage vector indicators was evaluated. The 6 types of reconstructed space voltage vector combinations were quantitatively compared, and the combination with the highest evaluation score in the analytic hierarchy process was selected for model predictive harmonic control. Simulation and experimental results showed that compared with conventional control strategies, the proposed strategy could effectively control harmonics and balance the midpoint voltage of the DC side of the APF. [ABSTRACT FROM AUTHOR]