Search

Seven fatty acids were detected by GC-MS in Xanthoceras sorbifolium Bunge seed oil extracted at different temperatures, including Palmitic acid C16:0, Stearic acid C18:0, Oleic acid C18:1, Eicosenoic acid C20:1, Docosenoic acid C22:1, Tetracosenoic acid C24:1, and Linoleic acid C18:2. The highest content of nervonic acid (NA) was found in Xanthoceras sorbifolium Bunge seed oil extracted at 70 °C. Three methods were selected to analyze the extraction rate of nervonic acid in Xanthoceras sorbifolium Bunge seed oil, including urea complexation, low-temperature solvent crystallization, and a combined treatment using these two methods. The final content of nervonic acid obtained was 14.07%, 19.66%, and 40.17%, respectively. The combined treatment method increased the purity of nervonic acid in Xanthoceras sorbifolium Bunge seed oil by 12.62 times. Meanwhile, thermogravimetric behavior analysis of samples extracted using different methods was conducted by thermogravimetric analyzer, which suggested that the thermal stability of the samples extracted by the combined treatment was enhanced. These results can provide a new process parameter and scientific basis for the extraction of NA. At the same time, FTIR and NMR were also used to characterize the combined extraction sample, and the structure of the samples was proved. [ABSTRACT FROM AUTHOR]

Prickly ash peel oleoresin (PPO) is a highly concentrated oil of Prickly ash essential oil and has a stronger aroma. However, its low water solubility, high volatility, difficulty in transport and storage, and decomposition by light, heat, and oxygen limit its wider application. To solve this problem, this study used freeze-drying or spray-drying, with soybean protein isolate (SPI) or gum Arabic (GA), combined with aqueous maltodextrin (MD) as the encapsulating agents to prepare four types of PPO microcapsules (POMs). Spray-dried microcapsules with GA as the encapsulating agent achieved a high encapsulation efficiency (EE) of 92.31 ± 0.31%, improved the thermal stability of the PPO, and had spherical morphology. (Headspace solid-phase microextraction/gas chromatography–mass spectrometry) HS-SPME/GC-MS detected 41 volatile compounds in PPO; of these, linalool, β-myrcene, sabinene, and D-limonene were identified as key flavor components. Principal component analysis (PCA) effectively distinguished the significant differences in flavor between PPO, spray-dried SPI/MD microcapsules (SS), and spray-dried GA/MD microcapsules (SG). During 15 days of air-exposure, the loss of flavor from SG (54.62 ± 0.54%) was significantly lower than PPO (79.45 ± 1.45%) and SS (57.55 ± 0.36%). During the air-exposure period, SG consistently had the highest antioxidant capacity, making it desirable for PPO packaging, and expanding its potential applications within the food industry. [ABSTRACT FROM AUTHOR]

With global climate change looming large, there is an urgent need for China's energy sector to take steps towards carbon neutrality. This study aims to explore how digital technologies can contribute to the pathway for China's energy sector to achieve carbon neutrality. By analyzing carbon neutrality policies and digital technology applications, we propose a systematic pathway framework to guide China's energy sector in integrating digital technology to accelerate the pace of achieving carbon neutrality in the energy sector. We first review the current status of carbon emissions and carbon neutrality targets in China's energy sector, and in light of the development trend of modern digital technologies, we propose key application areas for digital technologies in realizing carbon neutrality in the energy sector. Second, we detail the specific applications and effects of digital technologies in energy supply side optimization, energy utilization efficiency improvement, carbon sink management, and smart grid construction. Through theoretical modeling and empirical analysis, we demonstrate the great potential of digital technologies in carbon emission reduction and carbon neutrality in the energy sector and reveal the key role of digital technologies in carbon–neutral pathways. Finally, we propose effective technology implementation measures and point out important challenges and solution paths for digital technologies in carbon–neutral practices. This study provides a scientific basis and guidance for China's energy sector to achieve carbon neutrality with the help of digital technologies and promotes the important steps towards carbon neutrality in China. [ABSTRACT FROM AUTHOR]

Under construction industry upgrading and environmental protection requirements, promoting prefabricated buildings is very important, but its development varies significantly in different regions. For example, it only accounts for 20% of the new construction area in China, and the overall development level is low. The promotion of prefabricated buildings involves multiple interests. Then, how to encourage all stakeholders to work together to promote its development is a crucial issue. This study obtains an evolutionary game model among the government, developers, and purchasers. Then the stability strategies of the stakeholders are given conditions. Finally, numerical simulation is used to validate theoretical findings and determine the sensitivity of key parameters to a subject's behavior. The results show that: (1) There are two key factors that restrict the cooperation of stakeholders to promote prefabricated buildings, including the lack of government subsidies and the weak demand of the purchasers; (2) The government's overall subsidy should not be too high, exceeding the government's expenditure on environmental protection, and the subsidies for developers and purchasers must be reasonably allocated to effectively compensate for development benefits and purchase costs under limited expenditures. (3) Improving the residential environment of prefabricated buildings can significantly enhance the vested interests of purchasers, make up for their purchase costs, increase their willingness to purchase, and thus reduce the sales risk of developers. [ABSTRACT FROM AUTHOR]

Volatile compounds (VOCs) present in the oil extracted from yellow horn seeds were first analyzed using GC-IMS and GC-O-MS at varying roasting temperatures. A total of 97 VOCs were detected using GC-IMS, while 77 were tentatively identified using GC-O-MS. Moreover, both methods allowed the identification of 24 VOCs, of which the type of aldehydes is the most abundant. Combining the results of GC-IMS, GC-O-MS, OAVs, and VIP, it was concluded that hexanal, 2,5-dimethylpyrazine, heptanal, 2-pentylfuran, 1-hexanol, and 1-octen-3-ol were the key aroma compounds. The PLS-DA and OPLS-DA models have demonstrated the ability to discriminate between different oil roasting temperatures with high accuracy. The roasting temperature of 160 °C was found to yield the highest content of main aroma substances, indicating its optimality for yellow horn seed oil production. These findings will prove beneficial for optimizing industrial production and enhancing oil aroma control. [ABSTRACT FROM AUTHOR]

School buildings gather a large number of underage students, and the disastrous consequences of fire in such buildings are very serious, which is one of the key concerns of society in fire prevention and control. This study takes a "[" type kindergarten teaching building as the background and constructs a BIM–FDS building fire simulation model to reveal the fire smoke dispersion law under the coupling of the typical building structure and fire protection systems. The results show that the stairwells on both sides of the "[" type building are the main channels for the diffusion of fire smoke, and the asymmetry of the stairwell structure will cause apparent differences in the diffusion of smoke. Using the natural smoke exhaust in the stairwells of low-rise buildings does not aggravate the spread of smoke in the building and is conducive to smoke emissions. The high-pressure water mist system is superior to the water spray system in fire extinguishing and controlling room temperature. While it reduces smoke exhaust performance, it does not adversely affect personnel evacuation. This study systematically reveals the law of diffusion of fire smoke from "["-type teaching buildings, which can support the design of similar building structures, ventilation, fire protection, and the formulation of fire escape plans. [ABSTRACT FROM AUTHOR]

The bidding price is one of the important factors for construction enterprises in winning a bid. In the context of public bidding in the construction industry, in the process of group competition, how to estimate the individual bids to calculate their maximum value and the best price to improve the winning probability has become an important issue. In this research, based on the real option theory, the concept of group bidding environment is introduced to establish a real option price decision-making model for construction projects. The function of the model covers two external competitive environments: independent and coupled. Finally, through model inspection and parameter sensitivity analysis, the model is discussed in depth, and suggestions for model application are obtained. The research results show that the rule of the model results has optimization characteristics, and the numerical solution is consistent with the analytical solution, which has a certain price guidance role. In the independent bidding environment, their optimal bidding price is inversely proportional to the volatility level and the option period, and it is directly proportional to the estimated costs but has no obvious relationship with the number of competitors. Moreover, the average sensitivity of the optimal bidding price to the estimated costs, the volatility level and the option period are 35.06%, 9.77% and 7.70%, respectively; the optimal mark-up ratio is 1.078. In the coupled bidding environment, the concentration of competitors' prices and the optimal price will increase significantly, by about 2.37%, and the corresponding winning probability and weighted option value will increase by about 9.36% and 28.03%, respectively. The research results can provide price optimization for bidding activities with real option characteristics and improve the price winning rate, but the selection of price mode and parameter setting need to be set by enterprises according to industry characteristics and actual conditions. [ABSTRACT FROM AUTHOR]

With the implementation of urban central rail transit and old city reconstruction projects, construction vehicles frequently enter and depart the urban area. And because of its large volume and other characteristics, it increases the risk probability and severity of urban traffic accidents. This study takes the transportation path selection of construction vehicles as the breakthrough point, weighs the transportation efficiency and safety of construction vehicles, establishes a bi-objective optimization model, involving constraints such as height limit, weight limit, speed limit, direction limit and traffic limit and uses genetic algorithm to solve it. Finally, through case analysis, the user preference is adjusted to conduct functional test and description of the model. The results indicate that the model has the function of transportation vehicle path optimization. In the meantime, compared with the safest route, the time-consuming of the optimal route decreases by 16% and the risk increases by 7.4%, while the time-consuming of it increases by 5% and the risk decreases by 15.4% compared with the shortest route. Moreover, the corresponding coefficients of time-consuming and safety preference can reach about 0.65, and the relevant stakeholders have high acceptance of the route. Further improvement of construction vehicle management mechanism based on path optimization is one of the limited ways to effectively improve the current situation of construction vehicle management. [ABSTRACT FROM AUTHOR]

Ice dams are among the important risks affecting the operational safety and water conveyance efficiency of water diversion projects in northern China. However, no evaluation indicator system for ice dam risk assessment of water diversion projects has been proposed. Therefore, in this paper, based on the formation mechanism of ice dams, the risk assessment indicator system and the possibility calculation model of ice dams were both proposed for water diversion projects based on the fuzzy fault tree analysis method. The ice dam risk fault tree constructed in this study mainly includes three aspects: ice production, ice transport, and ice submergence conditions. Eighteen basic risk indicators were identified, and 72 minimum cut sets were obtained by using the mountain climb method. Eight risk indicators were determined as the key risk indicators for ice dams, including meteorological conditions, narrowed cross section, sluice incident, erroneous scheduling judgment, ice cover influence, flat bed slope, control structures, and ice flow resistance of piers. Then, the canal from the Fenzhuanghe sluice to the Beijumahe sluice of the Middle Route of the South-to-North Water Diversion Project was taken as the research object. Combined with the expert scoring method, the ice dam risk probability of the canal was determined to be 0.2029 × 10−2, which was defined as a level III risk, which is an occasionally occurring risk. The study results can support ice dam risk prevention and canal system operation in winter for water diversion projects. [ABSTRACT FROM AUTHOR]

With the urban renewal and development, the impact of urban construction projects such as old city reconstruction on the surrounding environment has always attracted social attention in the construction process. The strategies of the participants in the project construction in the process of environmental protection need to be further clarified. Taking the government investor and contractor as the construction subject, combined with questionnaire survey and evolutionary game, determines the three-party evolutionary stable game strategy and clarifies the internal mechanism of the evolution trend of the construction subject through simulation. The results show that the investor and contractor have a certain awareness of environmental protection, but they have limited understanding of the relevant policies and regulations issued by the government and believe that the government has little supervision and governance. The optimal evolutionary stability strategy adopted by the construction subject in promoting environmental protection is {Incentive, Effective supervision, Proper protection}, in which the stability conditions are J1 > M1 and T1 > N1. Reducing G1, A, M1, N1 and T1 or increasing J1 and the construction subject's willingness to take measures can promote the model to stabilize and evolve. The government should establish and improve the incentive system, improve the environmental protection awareness of the construction subject, urge the investor and the contractor to take effective measures to achieve the long-term stability goal of the tripartite subject strategy, and minimize the impact on environmental protection. [ABSTRACT FROM AUTHOR]

According to the hydraulic conditions and differences between rivers and long-distance canal systems, a juxtaposition floating ice cover model has been developed to ensure the safety of long-distance canal system operations in winter based on a flow regulation plan for canal systems and predictions of cold waves. The model can describe the ice cover formation process in the pools of each canal and the accompanying hydraulic responses and changes to the gate opening process. The model has been used to simulate the operation processes of the Jingshi canal portion of the middle route of the South-to-North Water Diversion Project in winter. The simulation results show the importance of obtaining accurate data on the ice cover roughness changing process and initial thickness, critical value of the area ice concentration upon formation, and maximization of flow velocity to ensure the juxtaposition of ice cover formation. The model can be used to determine the flow target and predict the gate operations of the canal system when a period of frigid weather is forecast. [ABSTRACT FROM AUTHOR]