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Apocynum venetum L. is a traditional Chinese medicinal herb with great potential to treat angiocardiopathy. Its major medicinal constituents are flavonoids. However, the natural habitats of A. venetum are typically affected by salt stress, which can modify both biomass and accumulation of medicinal compounds. In this study, the effects of salt stress on growth and development of A. venetum, accumulation of flavonoids and expression patterns of genes involved in flavonoid biosynthesis were evaluated. In general, the growth and development of seedlings (seedling height, root length, leaf length, leaf width and seed germination) were inhibited by salt stress. Unlike typical halophytes, there was no optimal NaCl concentration range that promoted growth and development, but seedlings had an elevated DW/FW ratio under salt stress (induced by irrigation with 50, 100, 200 or 400 mm NaCl). Furthermore, quercetin and kaempferol were significantly accumulated in A. venetum seedlings under salt stress, resulting in a balanced content and reduced FW. Moreover, the expression of AvCHS, AvCHI and AvF3GT was inhibited by salt stress; however, AvF3'H, AvF3H and AvFLS, which are involved in the flavonol synthesis pathway, were up-regulated under salt stress, consistent with a decrease in total flavonoids and an increase of flavonols (quercetin and kaempferol). In summary, cultivation of A. venetum in saline soils appeared to be feasible and improved the medicinal quality of A. venetum (quercetin and kaempferol accumulation under salt stress), thus this species can effectively utilize saline soil resources.

Microwave-assisted hydrothermal extraction of non-structural carbohydrates and hemicelluloses from tobacco biomass was investigated. Non-structural carbohydrates extraction was optimized by an Optimal design. The maximum yields for the leaf and stem were 118.57 mg/g and 120.33 mg/g biomass, respectively. The extracted stem residue was further treated for hemicelluloses extraction. A temperature of 200 °C without holding was proved to be the most efficient condition to produce a hemicelluloses yield of 105.15 mg/g. GPC results showed that the Mw values of precipitated hemicelluloses decreased from 143.5 kDa to 13.25 kDa with increasing temperature and holding time, while the un-precipitated fraction were ranging from 11.83 to 4.88 kDa. Monosaccharide analysis revealed that hemicelluloses extracted at lower temperature are heterogeneous compositional type, including xylan, glucuronoxylan and xylanglucan, while the ratio of xylose increased significantly (up to 72.64%) with increasing temperature. The developed microwave-assisted hydrothermal extraction process opens new avenues for a sustainable tobacco-based biorefinery.

This paper proposes a dispatch strategy for the multi-energy system (MES) that utilizes the district heating network (DHN) to realize the heat power interaction of multi cogeneration system, so as to improve the operational flexibility. A novel model for the DHN that couples multi heat sources and is under quantity regulation is proposed, based on which an optimal coordinated dispatch model (OCDM) for the MES is presented comprehensively. The DHN model comprises dispatch constraints (DCs) and linear system of temperature correction equations (TCEs). The DCs form part of the OCDM constraints, where the mass flow temperatures are treated as constants and the mass flow rates and heat power are decision variables. The TCEs are employed to update the mass flow temperatures in DCs. Subsequently, an iterative solving strategy for the OCDM is proposed. The convergence of the solving strategy is analyzed and an effective method is introduced to ensure the convergence. A modified system based on an actual MES in Changchun, China is researched in the case study. Three cases are given to verify the effectiveness of the dispatch strategy and the solution method as well as study the influence of wind power penetration and heating level to the results.

With the expanding application of natural ester insulating transformers in distribution area, the economic operation of distribution network becomes more and more important in order to reduce the overall cost in a distribution transformer’s life cycle. The imbalanced three-phase load increases the loss of transformers, and results in low voltage problem in the heavy load phase or even damages to customer’s electrical equipment. In this paper, a multi-objective optimal commutation mathematical model is established and verified to optimize the performance of the three-phase load imbalance regulation based on commutation switches. Compared with the common devices such as reactive compensation and SVG, the real-time online commutation switch system with an automatic commutation control strategy based on proposed vector genetic algorithm displays a better performance in reducing the power loss of distribution area as well as in solving the low voltage problem of users. We expect it to be a competitive solution for the economic and efficient operation of the distribution power grid.

As the global energy crisis, environmental pollution, and global warming grow in intensity, increasing attention is being paid to combined cooling, heating, and power (CCHP) systems that realize high-efficiency cascade utilization of energy. This paper proposes a bilateral transaction mechanism between a residential CCHP system and a load aggregator (LA). The variable energy cost of the CCHP system is analyzed, based on which an energy pricing strategy for the CCHP system is proposed. Under this pricing strategy, the electricity price is constant, while the heat/cool price is ladder-shaped and dependent on the relationship between the electrical, heat, and cool loads. For the LA, an integrated demand response program is proposed that combines electricity-load shifting and a flexible heating/cooling supply, in which a thermodynamic model of buildings is used to determine the appropriate range of heating/cooling supply. Subsequently, a two-stage optimal dispatch model is proposed for the energy system that comprises the CCHP system and the LA. Case studies consisting of three scenarios (winter, summer, and excessive seasons) are delivered to demonstrate the effectiveness of the proposed approach, and the performance of the proposed pricing strategy is also evaluated by annual operation simulations.

L-glutathione (GSH) capped ZnSe quantum dots (QDs) were prepared by microwave-assisted aqueous synthesis. Then, the resulting QDs were illuminated under dark, ultraviolet light and incandescent light, respectively. Thereby effect of lighting on the structures and properties of QDs were studied systematically. It was revealed that particle size and element content of QDs took a sharp change after irradiation, while the crystal structure maintains nearly unaffected. Comparing to the ZnSe QDs under dark condition, counterparts irradiated by UV light possessed outstanding sphericity, size distribution and dispersion. And the content of sulfur (S) in ZnSe QDs irradiated by UV light was much higher relatively. The effect of lighting on vibration peaks of O-H was considerable. However, this effect was observed to be weak on other chemical bonds. The possible explanation ascribes to photo-chemical interactions can occur between S-H and O-H bonds on the surface of GSH ligand. The lighting induced GSH to occur photocatalytic oxidation on the surface of ZnSe QDs, which improved the optical properties of QDs. The effects of lighting rely on irradiation types, the sequence is UV light, incandescent light and dark from high to low.

Live line operation is the most direct and effective means for the maintenance of multi-circuit transmission lines on the same tower. It is also a special operation mode developed to improve the reliability of power supply and the safety of power grid. Therefore, it is necessary to analyze the feasibility of live line operation of multi-circuit transmission lines on the same tower. In this paper, 110 kV, 220 kV and 500 kV multi-circuit transmission lines on the same tower are taken as object, and the safety analysis of live working is carried out for typical working positions. According to the results of operation impact discharge test, the risk rate and safe working distance of live working are obtained; Finally, the minimum effective insulation length of load-bearing tools and operation tools is calculated.

500kV double circuits on the same tower can effectively improve the natural transmission power and reduce the width of the line corridor, but the electromagnetic environment under the conductor is deteriorated. In order to ensure the safety of the workers in the insulated aerial vehicles and equipment during the live working, this paper firstly calculates the electric field distribution on the operating surface of the 500kV double-circuits truck with the actual line parameters, and then defines the distance coefficient. The existing minimum safe distance formula is modified, and a reference calculation method of the distance coefficient is given in combination with the data in the paper. Finally, the simulation data is used to verify.