摘要：Homogeneous redox mediation is efficient in alleviating the shuttling effect and slow redox kinetics of lithium polysulfides in lithium-sulfur ***,their perfect performance is not fulfilled owning to the fact that the multi-step transformation of lithium polysulfides requests the multifunctional active positions for the tandem *** on the redox comediation principles,a promoter of mixing organodiselenide and organoditelluride(mixed-Se/Te)was raised to induce tandem catalysis and boost the effective electrochemical conversion of lithium *** specifically,diphenyl diselenide facilitated the liquid-liquid and solid-liquid transformation between lithium polysulfides and sulfur,while diphenyl ditelluride improved the solid-liquid transformation concerning lithium sulfide ***,even under high sulfur loading of 6.5 mg cm^(−2) and low electrolyte/sulfur ratio of 5.88μL mg^(−1),the 10 mM low concentration mixed-Se/Te promoter offered a high discharge capacity of 6.6 mAh cm^(−2) and high rate performance of 4.1 mAh cm^(−2) at 0.5 ***,the assembled 1.5 Ah-level lithium-sulfur pouch cells provide an energy density of 332 Wh kg^(−1) at 0.05 C and good cycling *** research demonstrates the applicability of propelling continuous sulfur conversion reactions with detached active positions and is anticipated to stimulate deep molecular design of kinetic promoter to targeted energy-associated redox reactions.

摘要：The influence of ramps on the transient rolling contact characteristics and damage mechanisms of switch rails remains unclear,presenting substantial challenges to the safety of railway *** this end,this paper constructs a transient rolling contact finite element model of the wheel-rail in switch under different ramps using ANSYS/LSDYNA method,and analyzes the tribology and damage characteristics when the wheel passes through the switch at a uniform *** research findings reveal that the vibration induced in the switch rail during the wheel load transfer process leads to a step-like increase in the contact ***,the interaction between the wheel and the rail primarily involves slip contact,which may significantly contribute to the formation of corrugations on the switch ***,the presence of large ramps exacerbates switch rail wear and rolling contact fatigue,resulting in a notable 13.2%increase in switch rail damage under 40‰ramp conditions compared to flat(0‰ramp)***,the large ramps can alter the direction of crack propagation,ultimately causing surface spalling of the ***,large ramps intensify the dynamic interactions during the wheel load transfer process,further aggravating the crack and spalling damage to the switch rails.

摘要：For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.

摘要：In order to realize the computer aided design of AT shifting element schemes, a mathematical model of shifting element schemes which can be easily identified by computers was built. Taking the transmission ratio sequence as an optimization objective and simple shifting logic between adjacent gears through operating only one shifting element as a constraint condition, a fitness function of shifting element schemes was proposed. ZF-8AT shifting element schemes were optimized based on GA work-box of MATLAB, and the feasibility of the optimization algorithm was verified.

摘要：In recent few years, significant improvement has been made in developing largescale 3D printers to accommodate the need of industrial-scale 3D printing. It is of great feasibility to construct structural components and buildings by means of 3D concrete printing. The major issues of this innovative technique focus on the preparation and optimization of concrete materials which possess favourable printable properties as well as the measurement and evaluation methods of their workability. This paper firstly introduces three largescale 3D printing systems that have been successfully applied in construction industry. It then summarizes the commonly used raw materials in concrete manufacturing. Critical factors that should be particularly controlled in material preparation are specified. Easy-extrusive, easy-flowing, well-buildable, proper setting time and low shrinkage are significant for concrete mixture to meet the critical requirements of a freeform construction process. Thereafter, measuring methods that can be employed to assess the fresh and hardened properties of concrete at early stages are suggested. Finally, a few of evaluation methods are presented which may offer certain assistance for optimizing material preparation. The objective of this work is to review current design methodologies and experimental measurement and evaluation methods for 3D printable concrete materials and promote its responsible use with largescale 3D printing technology.

摘要：In order to improve the strength and stiffness of shield cutterhead, the method of fuzzy mathematics theory in combination with the finite element analysis is adopted. An optimal design model of structural parameters for shield cutterhead is formulated,based on the complex engineering technical requirements. In the model, as the objective function of the model is a composite function of the strength and stiffness, the response surface method is applied to formulate the approximate function of objective function in order to reduce the solution scale of optimal problem. A multi-objective genetic algorithm is used to solve the cutterhead structure design problem and the change rule of the stress-strain with various structural parameters as well as their optimal values were researched under specific geological conditions. The results show that compared with original cutterhead structure scheme, the obtained optimal scheme of the cutterhead structure can greatly improve the strength and stiffness of the cutterhead, which can be seen from the reduction of its maximum equivalent stress by 21.2%, that of its maximum deformation by 0.75%, and that of its mass by 1.04%.

摘要：This paper studies dynamic pricing and cooperative advertising strategies in a two-member channel of distribution. We propose differential game models that incorporate the carryover effects of advertising over time for both manufacturer and retailer. Two different models are studied. Firstly, we discussed a non-cooperative differential game which the manufacturer supports partially the cost of the promotion activities. Secondly, both channel members cooperatively determine their respective strategies. In these two cases, dynamic cooperative advertising and pricing strategies are characterized. Then numerical simulation method is applied to analyze the sensitivity of main model parameters and compare the main results of the two models. The simulation results show that the cooperative model achieves better coordination than the non-cooperative model with the following features： all channel members achieve higher advertising efforts and profit level in the cooperative case rather than in the non-cooperative case.

摘要：In order to ensure overall optimization of the underground metal mine production scale, multidisciplinary design optimization model of production scale which covers the subsystem objective function of income of production, safety and environmental impact in the underground metal mine was established by using multidisciplinary design optimization method. The coupling effects from various disciplines were fully considered, and adaptive mutative scale chaos immunization optimization algorithm was adopted to solve multidisciplinary design optimization model of underground metal mine production scale. Practical results show that multidisciplinary design optimization on production scale of an underground lead and zinc mine reflect the actual operating conditions more realistically, the production scale is about 1.25 Mt/a (Lead and zinc metal content of 160 000 t/a), the economic life is approximately 14 a, corresponding coefficient of production profits can be increased to 15.13%, safety factor can be increased to 5.4% and environmental impact coefficient can be reduced by 9.52%.

摘要：The Efficient Global Optimization(EGO)algorithm has been widely used in the numerical design optimization of engineering ***,the need for an uncertainty estimator limits the selection of a surrogate *** this paper,a Sequential Ensemble Optimization(SEO)algorithm based on the ensemble model is *** the proposed algorithm,there is no limitation on the selection of an individual surrogate ***,the SEO is built based on the EGO by extending the EGO algorithm so that it can be used in combination with the ensemble ***,a new uncertainty estimator for any surrogate model named the General Uncertainty Estimator(GUE)is *** performance of the proposed SEO algorithm is verified by the simulations using ten well-known mathematical functions with varying *** results show that the proposed SEO algorithm performs better than the traditional EGO algorithm in terms of both the final optimization results and the convergence ***,the proposed algorithm is applied to the global optimization control for turbo-fan engine acceleration schedule design.

摘要：The serrated incisors of grasshopper [Chondracris rosea rosea （De Geer）] possess an advantageous capacity for cutting plant fiber. Inspired by this special geometrical structure of incisors, bionic saw blade was designed and manufactured. MATLAB software digital image processing technology was used to obtain outer margin profile from stereomicroscope pho- tograph of the serrated incisors. The outer margin profile of incisors was fitted and expressed by six-order polynomial function. To compare the cutting capacity of bionic and traditional saw blades, the internodes of dry corn stalks were cut perpendicularly. Cutting force-deformation characteristics were obtained by universal testing machine. The results of cutting experiments show that the maximum cutting force of bionic saw blade was 128.26 N, which is 15.87% lower than 152.45 N of traditional saw blade; the average cutting force of bionic saw blade was 51.56 N, which is 28.17% less than 71.78 N of traditional saw blade. Meanwhile, the cutting energy consumption of bionic saw blade was 8.95 J, which is 12.85% less than 10.27 J of traditional saw blade. Overall, the bionic saw blade can lead to noticeable reduction of the cutting force and energy. These results will be helpful for designing cutting elements of corn stalk harvesting, biomass size reduction and other processing machinery.