Co-gasification of rural solid waste and biomass in rural areas: Simulation and plant-scale process.

Co-gasification technology is considered to be one of the most potential technologies for solid waste treatment, and the co-gasification treatment of rural solid waste (RSW) and biomass can effectively promote waste reduction and resource utilization. In the present study, the co-gasification of RSW and biomass in an updraft fixed bed gasifier was simulated using the Aspen Plus software, where the simulation results were validated via plant-scale experiments. In this scenario, the impacts of biomass source (i.e., rice husk, rice straw, tree bark and corn straw), co-gasification ratio (CGR) (0-40%) and air equivalence ratio (AER) (0.30-0.55) on the performance of the fixed-bed were investigated. Results showed that Aspen Plus could describe the plant-scale co-gasification process well. Besides, the tree bark-RSW system had the highest heat conversion efficiency of 6.00 MJ/kg the simulation temperature of the gasification layer increased greatly from 485 to 913 °C when the AER increased from 0.40 to 0.55. In addition, the co-gasification of RSW and tree bark could achieve the highest efficiency at the AER of 0.45 and CGR of 20% w, in which the gasification temperature reached 799 °C with the gasification efficiency of 57.17%. This study explored the use of co-gasification of RSW and biomass in rural areas by simulation and plant-scale processes, which promotes the commercial application of co-gasification technology and contributes to sustainable waste management in rural areas.

Traffic Load Optimization for Multi-Satellite Relay Systems in Space Information Network: A Proportional Fairness Approach.

Backbone satellites in a space information network (SIN) can be used as air base stations or data relay satellites (DRSs) to realize cross-system, cross-network and long-distance relay transmission. In this paper, a traffic load optimization problem for multi-satellite relay systems in SIN is considered to achieve highly efficient cooperative transmission and improve resource utility. A model of SIN based on a distributed satellite cluster (DSC) is considered, and the characteristics of the model are analyzed. Based on this, a hybrid resource management architecture combining distributed and central resources control schemes is proposed to realize a centrally controllable and distributed optimization of resources to meet various comprehensive service requirements. Two scenarios of multi-satellite relay systems in SIN are given, and traffic load optimization problems with joint bandwidth and power allocation for these two scenarios are formulated based on proportional fairness (PF) criterion to achieve traffic load balancing with considerable system capacity. The optimization problems in these two scenarios are proved to be a convex optimization problem with mathematical analysis, and the closed-form solutions of two problems in their dual domain are derived by dual transformation. With the closed-form solutions, two iterative algorithms based on the subgradient method are designed under the proposed hybrid resource management architecture to solve the problems in this paper. Simulation results show that the proposed schemes can effectively improve the upper bound of system capacity by resource sharing and cooperative relay, and it can balance the traffic load well with guarantees of a reasonable level system capacity compared with existing methods.

A prediction model on rockburst intensity grade based on variable weight and matter-element extension.

Rockburst is a common dynamic disaster in deep underground engineering. To accurately predict rockburst intensity grade, this study proposes a novel rockburst prediction model based on variable weight and matter-element extension theory. In the proposed model, variable weight theory is used to optimize the weights of prediction indexes. Matter-element extension theory and grade variable method are used to calculate the grade variable interval corresponding to the classification standard of rockburst intensity grade. The rockburst intensity grade of Engineering Rock Mass is predicted by rock burst intensity level variable and the interval. Finally, the model is tested by predicting the rockburst intensity grades of worldwide several projects. The prediction results are compared with the actual rockburst intensity grades and the prediction results of other models. The results indicate that, after using variable weight theory and grade variable method, the correct rate of prediction results of matter-element extension model is improved, and the safety of the prediction results is also enhanced. This study provides a new way to predict rock burst in underground engineering.

Synthesis and theoretical studies on the vibration of a novel (3,4-disfluoro)phenylquione.

A novel (3,4-disfluoro)phenylquione (2F-PQ) was synthesized through the reaction of 3,4-Difluoroaniline and 1,4-benzoquinone. Its structure was verified by (1)H NMR, FTIR and Raman spectra. The ground-state geometries were optimized by using density functional theory (DFT) at B3LYP/6-311G+(d,p), B3PW91/6-311G+(d,p) and MPB3PW91/6-311G+(d,p) level without symmetry constrains, respectively. The predicted FTIR and Raman spectra scaled by factor are well consistent with experimental spectra.

9-[4,5-Bis(benzyl-sulfan-yl)-1,3-dithiol-2-yl-idene]-4,5-diaza-fluorene.

In rhe title compound, C(28)H(20)N(2)S(4), the 1,3-dithiol-2-yl-idene and 4,5-diaza-fluoren-9-one (dafone) groups are almost coplanar, making a dihedral angle of only 5.65 (4)°. The two benzyl groups are on different sides of the 1,3-dithiol-2-yl-idene ring, forming a dihedral angle of 35.54 (2)°.