摘要：Zero-dimensional perovskite materials,characterized by broadband emission caused by self-trapped excitons,are promising materials for stimuli-responsive and photo-writeable ***,existing research is focused on the effects of structural phase transitions on photophysical properties,and lacks in-depth understanding of the mechanisms of self-trapped excitons ***,we demonstrate that the dehydration reaction in zero-dimensional antimony halide clusters significantly enhances the self-trapped excitons emission without inducing structural phase transition,resulting in a substantial increase in photoluminescence(PL)quantum yield from 3.5%to 91.4%.In-situ X-ray diffraction and PL techniques were employed to shed light on the relationship between the crystal structure and radiative recombination,demonstrating the introduction of rich lattice distortion during the dehydration ***-dependent PL spectra and transient absorption spectra suggest that the lattice distortion causes the moderate electron-phonon coupling strength and high exciton binding energy,facilitating self-trapped excitons to relax from the non-radiative recombination singlet state to the radiative recombination triplet state,corresponding to the enhanced emission *** a proof of concept,several switchable PL applications have been established in scenarios such as anti-counterfeiting,rewritable luminescent paper,and humidity *** finding elucidates the emission mechanism of self-trapped excitons and provides a novel avenue for designing switchable luminescent materials.

摘要：This work was focused on the model-based design method of two-axis four-actuator(TAFA) fast steering mirror system(FSM), in order to improve the design efficiency. The structure and operation principle commonality of normal TAFA FSM were investigated. Based on the structure and the commonality, the conditions of single-axis idea, high-frequency resonance and coupling were modeled gradually. Combining these models, a holonomic system model was established to reflect and predict the performance of TAFA FSM. A model-based design method was proposed based on the holonomic system model. The design flow and design concept of the method were described. In accordance with the method, a TAFA FSM was designed. Simulations and experiments of the FSM were done, and the results of them were compared. The compared results indicate that the holonomic system model can well reflect and predict the performance of TAFA FSM. The bandwidth of TAFA FSM is more than 250 Hz; adjust time is less than 15 ms;overshoot is less than 8%; position accuracy is better than 10 μrad; the FSM prototype can satisfy the requirements.

摘要：Traffic accidents involving pedestrians and drivers pose significant public health and safety *** the differential influences of road physical design attributes on crash frequencies for these two groups is critical for developing targeted safety *** that the zero-truncated characteristic of the data is uncertain,the results of the zero-truncated negative binomial models and traditional negative binomial models are calculated to seek the better *** result revealed that the road surface conditions and vertical and horizontal curvature have greater influence on both pedestrian and driver compared to number of lanes and speed *** speed limits were more pronounced for pedestrian crash frequency than driver ***,the effect of different types of intersections was stronger for driver crash *** differential influences of road physical design attributes on traffic crash frequencies for pedestrians versus drivers highlight the importance of adopting a user-centric approach to transportation safety planning and infrastructure *** interventions to address the unique needs and vulnerabilities of different road user groups can lead to more effective safety improvements and better overall traffic safety outcomes.

摘要：A novel hybrid algorithm named ABC-BBO, which integrates artificial bee colony(ABC) algorithm with biogeography-based optimization(BBO) algorithm, is proposed to solve constrained mechanical design problems. ABC-BBO combined the exploration of ABC algorithm with the exploitation of BBO algorithm effectively, and hence it can generate the promising candidate individuals. The proposed hybrid algorithm speeds up the convergence and improves the algorithm's performance. Several benchmark test functions and mechanical design problems are applied to verifying the effects of these improvements and it is demonstrated that the performance of this proposed ABC-BBO is superior to or at least highly competitive with other population-based optimization approaches.

摘要：This work considers those road networks in which there are multi-route choices for bifurcation-destination(or origin-destination) pairs, and designs a real-time variable message sign(VMS)-based routing control strategy in the model predictive control(MPC) framework. The VMS route recommendation provided by the traffic management authority is directly considered as the control variable, and the routing control model is established, in which a multi-dimensional control vector is introduced to describe the influence of route recommendations on flow distribution. In the MPC framework, a system optimum routing strategy with the constraints regarding drivers' acceptability with recommended routes is designed, which can not only meet the traffic management authority's control requirement but also improve drivers' satisfaction with the route guidance system. The simulation carried out shows that the proposed routing control can effectively mitigate traffic congestion, reduces followers' time delay, and improves drivers' satisfaction with routing control in road networks.

摘要：In order to solve the decoupling control problem of multivariable system with time delays,a new decoupling Smith control method for multivariable system with time delays was proposed. Firstly,the decoupler based on the adjoint matrix of the multivariable system model with time delays was introduced,and the decoupled models were reduced to first-order plus time delay models by analyzing the amplitude-frequency and phase-frequency characteristics. Secondly,according to the closed-loop characteristic equation of Smith predictor structure,proportion integration (PI) controllers were designed following the principle of pole assignment for Butterworth filter. Finally,using small-gain theorem and Nyquist stability criterion,sufficient and necessary conditions for robust stability were analyzed with multiplicative uncertainties,which could be encountered frequently in practice. The result shows that the method proposed has superiority for response speed and load disturbance rejection performance.

摘要：Electromagnetic forming is one of the high-rate forming methods that can be extensively used to form and join axisymmetric metal sheet and tube. Tendency of homogeneous radial deformation during electromagnetic compression of aluminium tube was investigated through the design optimization method based on sequential coupling numerical simulation and experiments. The results show that the tendency depends on the length ratio of tube to coil (R), which has a critical value (Rc) corresponding to the relatively homogeneous radial deformation along axial direction. The tube length relative to Rc is insensitive to the discharge voltage. When R is greater than Rc, the deformed tube presents horn shape and the shorter coil makes for local deformation. If R is less than Rc, the deformed tube presents drum shape and the longer coil contributes to larger deformation at tube end. Rc increases with coli length and could approach to 1; inversely, it could approach to 0. These results indicate the design optimization method based on the sequential coupling numerical simulation is feasible, which can be used to realize the controllable and precise deformation of metal tube.

摘要：Learning control for gradually varying references in iteration domain was considered in this research, and a composite iterative learning control strategy was proposed to enable a plant to track unknown iteration-dependent trajectories. Specifically, by decoupling the current reference into the desired trajectory of the last trial and a disturbance signal with small magnitude, the learning and feedback parts were designed respectively to ensure fine tracking performance. After some theoretical analysis, the judging condition on whether the composite iterative learning control approach achieves better control results than pure feedback contro! was obtained for varying references. The convergence property of the closed-loop system was rigorously studied and the saturation problem was also addressed in the controller. The designed composite iterative learning control strategy is successfully employed in an atomic force microscope system, with both simulation and experimental results clearly demonstrating its superior performance.

摘要：Single cell temperature difference of lithium-ion battery(LIB) module will significantly affect the safety and cycle life of the battery. The reciprocating air-flow module created by a periodic reversal of the air flow was investigated in an effort to mitigate the inherent temperature gradient problem of the conventional battery system with a unidirectional coolant flow with computational fluid dynamics(CFD). Orthogonal experiment and optimization design method based on computational fluid dynamics virtual experiments were developed. A set of optimized design factors for the cooling of reciprocating air flow of LIB thermal management was determined. The simulation experiments show that the reciprocating flow can achieve good heat dissipation, reduce the temperature difference, improve the temperature homogeneity and effectively lower the maximal temperature of the modular battery. The reciprocating flow improves the safety, long-term performance and life span of LIB.

摘要：A novel air-powered twin-rotor piston engine(ATPE) utilizing a differential velocity driving mechanism to achieve a high output torque was *** ATPE had eight separated rotary cylinders which can dynamically enlarge the engine displacement as a result of the special driving mechanism,which was named dynamic volume *** mathematical model of ATPE comprising a dynamic model and a thermodynamic model was established under the assumption of no mechanical *** model was numerically simulated in *** results show that shortage of low output torque confusing traditional air-powered engines can be *** average output torque sharply increases to 100 N·m,which is about three times that of traditional air-powered engines with equal cylinder displacement under the pressure of 0.6 MPa at 480 r/*** can be used to drive vehicles directly without transmission box,therefore the energy transfer efficiency of ATPE can be ***,benefitting from the novel gas distribution system,the engine shows an ability in self-adjusting under different *** arrangements of air ports automatically adjust the open interval of air ports according to the load,which may simplify the speed control system.