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Agarwood is a highly economically important medicinal herb with widespread uses, however, the difference between the biological activities of artificial and wild agarwood is unclear. In this study, the alcohol-soluble extracts of agarwood produced by fungi and natural agarwood were used to determine the differences between the overall biological activities. The antioxidant ability (the clearance rates of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+) radicals, and total reducing power), anti-acetylcholinesterase, and anti-α-glucosidase activity were determined by ultraviolet-visible spectrophotometry. The results indicated that with 2 mg/mL alcohol-soluble extracts, the scavenging DPPH radical rates of the artificial agarwood samples were 93.74–102.31% of that of the wild agarwood, and the ABTS+ radical clearance rates of the artificial agarwood samples were 75.38–95.52% of that of the natural agarwood. With 3.5 mg/mL alcohol-soluble extracts, the artificial agarwood samples had a total reducing power of 63.07–80.29% of that of the wild agarwood. With 4 mg/mL alcohol-soluble extract, the acetylcholinesterase activity inhibition rates of the artificial agarwood samples were 102.56–109.16% of that of the wild agarwood. With 1 mg/mL alcohol soluble extracts, the α-glucosidase effect inhibitions rates of the artificial agarwood samples were 68.32–100.39% of that of the wild agarwood.

Heartwood has a high economic value because of its natural durability, beautiful color, special aroma, and richness in active ingredients used in traditional Chinese medicine. However, the mechanism of heartwood formation remains unclear. Dalbergia odorifera was selected as the object of research to analyze this variation in the chemical composition of sapwood, transition zone, and heartwood as well as to elucidate the relationship between this variation and the formation of heartwood. The variation of secondary metabolites was analyzed using gas chromatography-mass spectrometry and ultra-high performance liquid chromatography–mass spectrometry, the variation of lignin was analyzed using Fourier transform infrared spectroscopy and ultraviolet visible spectrophotometry, and the variation law of mineral elements was analyzed using atomic absorption spectrophotometry. The results demonstrated that contents of characteristic secondary metabolites in Dalbergia odorifera were mainly distributed in heartwood (84.3–96.8%), increased from the outer to inner layers of the xylem, and sudden changes occurred in the transition zone (the fourth growth ring). The Dalbergia odorifera lignin can be identified as typical “syringyl–guaiacyl (S–G)” lignin, and the color darkened from the outside to the inside. The results demonstrated that there were more benzene rings and conjugated C=O structures in the heartwood. Additionally, the variation of minerals in the xylem was related to elemental types, the average concentrations of Mg, Ca, Fe and Sr were higher in the heartwood than in the sapwood, whereas the concentrations of K and Zn were higher in the sapwood than in the heartwood owing to the reabsorption of elements. The concentrations of Na and Cu were similar in the heartwood and sapwood. The composition and structural characteristics of secondary metabolites, lignin, and mineral elements in the three typical xylem regions (sapwood, transition zone and heartwood) of Dalbergia odorifera changed. The most abrupt change occurred in the narrow xylem transition zone, which is the key location involved in heartwood formation in Dalbergia odorifera.

Agarwood has high economic value and wide uses, however, the amount of wild agarwood is scarce. Wild agarwood with high oil content may contain strains associated with agarwood production. To improve the formation of agarwood, we produced fungal inducers from a high-oil wild agarwood block containing enrichment fungi. We investigated the composition of strains and inoculated the fungal inducers into Aquilaria trees. We analyzed the content of alcohol-soluble extract, essential oil, agarotetraol, 2-(2-phenylethyl)chromone, 6,7-dimethoxy-2-(2-phenylethyl)chromone and total chromone, and the chemical components of alcohol-soluble extract. We aimed to assess agarwood quality through these evaluations. The results demonstrated that fungi extracted from wild agarwood with high oil content can effectively improve the yield and quality of agarwood, and Gongronella butleri, Saitozyma podzolica, Cladorrhinum bulbillosum, Humicola grisea and Tetracladium marchalianum were the species found novel as inoculant for agarwood formation. After 12 months of inoculation, agarwood produced using A. sinensis had higher quality, the contents of alcohol-soluble extract, essential oil, total chromones, and the total relative contents of sesquiterpenes and chromones were 21.73 % ±2.97 %, 6.07 % ±0.47 %, 12.30 % ±2.21 %, and 97.59 %, respectively. Over 6–18 months of inoculation, agarotetrol content decreased, and 2-(2-phenylethyl) chromone and 6,7-dimethoxy-2-(2-phenylethyl)chromone content first increased and then decreased.

The assessment of fixed asset investment projects of energy conservation is based on a scientific and systematic approach to analyze the energy production, consumption and management and helps to analyze whether the use of energy is in line with the national and local industrial policies and whether the project design meets China׳s energy saving design outlines and industry standards. The level of energy consumption is compared to the domestic and international advanced levels regarding the project energy use and process analysis, in all aspects of energy production and energy consumption, taking technically feasible, economically reasonable and environmentally and socially responsible measures and effective and rational use of energy, to reduce consumption and losses and to stop waste, while investigating if the project has a certain advanced and rational use of energy. This study provides a full consideration of whether there is a scientific and rational use of energy to avoid low-level repetition construction, to avoid blind expansion trends, and to promote the upgrading of industrial structure. This paper takes as an example a gas turbine power plant in Shenzhen as an assessment case study of the potential energy savings. The project is expected to have an annual power supply of 37.89×10 8 kW h and an annual heat supply of 5.43×10 4 GJ. The consumption of power generation in tons of coal equivalent units is expected to reach 208 g per kW h. The comprehensive annual average thermal efficiency is 77.16%, and the average heat-to-power ratio is 40.65%. These technical indicators are thought to be one of the best compared to similar level projects in the country.

The vagueness of queries is a thorny problem of web search all the time. Because of the length of queries is general short, identifying user's search intent from a single query session is unpractical. In this paper, a result recommendation method which refers to the idea of swarm intelligent to optimizing the result list is proposed to solve this problem. In this method, users will be allocated to several communities where users have similar features of searching or other characteristics. And users will benefit from the search experience of co-community users when they search the repetitive queries. Furthermore, to optimizing the result list, the most relative results from similar users will be place ahead of the result page. Finally, experimental evaluation shows that our approach improves the accuracy of results and personalized user experience of searching.

Related query suggestion is very important for search engines. Users could find required information more quickly and accurately with the help of query suggestions, which could greatly improve users' search experience. Thus, query suggestion technology has become a research hotspot in the field of the search engine. Most of existing methods focused on the query log data to mine related queries. However, some of the query log data exist relatively sparse characteristics and have some interferential noise data. Besides, the method that only focus on query log trend to fail to consider the user's initial query intention. These shortages would reduce the accuracy of the recommendation. Thus, this paper proposes a query suggestion method based on random walk and topic concepts (QuS-RWTC). The method is based on the query log data and suggestions from other mature search engines, which could make the suggestions more comprehensive and obtain a higher coverage. In addition, the paper further executes procedures of topic concepts to re-order the candidate queries, which make the suggestions more accurate, since they are more satisfied to the user's initial intention. The results prove the excellent performance of QuS-RWTC method compared with traditional methods and validate the importance of topic concepts.

This paper presents an example of the energy balance and the efficiency analysis for power generation in internal combustion engine sets using biogas. Water-cooled engine can effectively reduce the cylinder wall temperature. Therefore, the working conditions of the cylinder components could be improved. Result of energy balance and efficiency calculation show that the engine set can generate electricity of 70.0 kW under a biogas yield of 34.84 m3/h in the standard state with the energy efficiency of 28.45% and the exergy efficiency correspond to 27.36%. The energy consumption of electricity generated was 432 g coal equivalent (kce) per each kW h. The thermal energy dissipated from the engine exhaust was the greatest of all and it was accounting for 40.34%. Whereas the recoverable thermal energy dissipated from the water in the cylinder jacket was approximately 26.86%. Thermal energy dissipated by radiation and convection from the engine only accounted for 2.99% of total energy input. How to improve the energy efficiency of biogas processed was discussed in this paper, for example, the biogas purification (removal of CO2 and H2S) to enrich methane in biogas, can be used for the power fuel, meanwhile, it enhances the efficiency of power generation. A CHP efficiency of over 80% can be achieved if heat of both the exhaust gas and water heated within the cylinder jacket is utilized.

A variable gain super-twisting sliding mode control is proposed for Hammerstein system where nonlinearity is implemented by Bouc-Wen model. Firstly, the Hammerstein system is transformed to the regular form. Then, three variable gains are designed for the super-twisting sliding mode control which can alleviate the chattering of the control. Finally, a Lyapunov theorem guarantees the stability of the control system and a finite-time rigorous convergence is proved for the variable gain super-twisting sliding mode control system. Simulation results verify the effectiveness of the proposed variable gain super-twisting algorithm (VGSTA).

Optimization of cutting parameters is very important issues in manufacturing engineering. For slender bar turning operations, drum-shaped error is one of the most important product quality characteristics. In this work, an artificial neural network model was developed firstly to describe the relationship between cutting parameters and drum-shaped error in slender bar turning process. Based on the obtained model, cutting parameter was optimized to satisfy the specified drum-shaped error and economics criterion in multi-pass turning of slender bar. Due to the high complexity of the machining optimization problem, genetic algorithm was employed to resolve this problem. Experimental results show that the proposed optimization method is both effective and efficient for slender bar turning operations.