摘要：Besides grid-to-vehicle(G2 V) and vehicle-to-grid(V2 G) functions, the battery of an electric vehicle(EV) also has the specific feature of mobility. This means that EVs not only have the potential to utilize the storage of cheap electricity for use in high energy price periods, but can also transfer energy from one place to another place. Based on these special features of an EV battery, a new EV energy scheduling method has been developed and is described in this article. The approach is aimed at optimizing the utilization EV energy for EVs that are regularly used in multiple places. The objective is to minimize electricity costs from multiple meter points. This work applies real data in order to analyze the effectiveness of the method. The results show that by applying the control strategy presented in this paper at locations where the EVs are parked, the electricity cost can be reduced without shifting the demand and lowering customer's satisfaction. The effects of PV size and number of EVs on our model are also analyzed in this paper. This model has the potential to be used by energy system designers as a new perspective to determine optimal sizes of generators or storage devices in energy systems.

摘要：According to the critical size ratio for the characteristic particle size to film thickness between grinding wheel and work, the machining mechanisms in abrasive jet precision finishing with grinding wheel as restraint can be categorized into four states, namely, two-body lapping, three-body polishing, abrasive jet machining and fluid hydrodynamic shear stress machining. The critical transition condition of two-body lapping to three-body polishing was analyzed. The single abrasive material removal models of two-body lapping, three-body polishing, abrasive jet finishing and fluid hydrodynamic shear stress machining were proposed. Experiments were performed in the refited plane grinding machine for theoretical modes verification. It was found that experimental results agreed with academic modes and the modes validity was verified.

摘要：A patented double-ring-plate gear reducer was designed and its dynamic performance was simulated. One unique characteristic of this novel drive is that the phase angle difference between two parallelogram mechanisms is a little less than 180 degree and four counterweights on two crankshafts are designed to balance inertia forces and inertia moments of the mechanisms. Its operating principle, advantages, and design issues were discussed. An elasto-dynamics model was presented to acquire its dynamic response by considering the elastic deformations of ring-plates, gears, bearings, etc. The simulation results reveal that compared with housing bearings, planetary bearings work in more severe conditions. The fluctuation of loads on gears and bearings indicates that the main reason for reducer vibration is elastic deformations of the system rather than inertia forces and inertia moments of the mechanisms.

摘要：Three-dimensional(3D)bioprinting has been used widely for the construction of hard tissues such as bone and ***,constructing soft tissues with complex structures remains a *** this study,complex structures characterized by both tunable elastic modulus and porosity were printed using freeform reversible embedding of suspended hydrogels(FRESHs)printing methods.A mixture of alginate and gelatin was used as the main functional component of the *** analysis showed that this bioink possesses shear thinning and shear recovery properties,supporting both cryogenic and FRESH printing *** printing capabilities and limitations of cryogenic and FRESH printing were then analyzed by printability tests.A series of complex structures were printed by FRESH printing methods which could not be realized using conventional *** tests and scanning electron microscopy analysis showed that the printed structure is of excellent flexibility and could be applied in various conditions by adjusting its mechanical modulus and porosity.L929 fibroblast cells maintained cell viability in cell-laden-printed structures,and the addition of collagen further improved the hydrogels’***,all results provided useful insight into the building of human soft tissue organ blocks.

摘要：AC motors, especially the squirrel cage induction motors have the advantages of simple structure, good reliability and low cost. They are more suitable to be used as electrical dynamometers to provide dynamic load for bench test systems. But, the speed and torque of induction motors are not easy to be controlled accurately. In this work, an electrical dynamometer based on the induction motor is proposed. In order to get better control performance of torque and speed of induction motor, an improved direct torque control method(DTC) is also developed based on the space vector modulation(SVM) technique. The performance of the proposed dynamometer system is validated in the Matlab/Simulink platform. The simulation results show that the new dynamometer has good torque and stator flux response. And the torque and stator current ripples of it are reduced significantly compared with using the conventional DTC method.

摘要：A new procedure for a design of multi-range controllers for use with highly nonlinear systems is *** procedure involves obtaining the describing function models of the nonlinear plant by software followed by designing a controller at nominal ***,the controller parameters are optimized to yield a satisfactory closed-loop response at all operating ***,the performance and stability of the closed-loop system comprised of the designed controller and the nonlinear plant are *** procedure and the associated software are applied to a nonlinear control problem of the sort encountered in aerospace,and the results are compared with two other approaches.

摘要：Flexure mechanisms with decoupled characteristics have been widely utilized in precision positioning ***,these mechanisms suffer from either slow response or low load ***,asymmetric design always leads to thermal *** order to solve these issues,a novel 2-DOF decoupled mechanism is developed by monolithically manufacturing sets of statically indeterminate symmetric（SIS） flexure structures in *** design helps to eliminate the thermal error and Finite Element Analysis（FEA） results show that the maximum coupling ratio between X and Y axes is below 0.25% when a maximum pretension force of 200 N is *** ignoring the mass effect,all the SIS flexure structures are simplified to ＂spring-damper＂ components,from which the static and dynamics model are *** relation between the first resonant frequency of the mechanism and the load is investigated by incorporating the load mass into the proposed dynamics *** results show that even with a load of 0.5 kg,the first resonant frequency is still higher than 300 Hz,indicating a high load *** mechanism＇s static and dynamic performances are experimentally *** linear stiffnesses of the mechanism at the working platform and at the driving point are measured to be 3.563 0 N·μm-1 and 3.362 1 N·μm-1,*** corresponding estimation values from analytical models are 3.405 7 N·μm-1 and 3.381 7 N·μm-1,which correspond to estimation errors of-4.41% and 0.6%,*** an additional load of 0.16 kg,the measured and estimated first resonant frequencies are 362 Hz and 365 Hz,*** estimation error is only 0.55%.The analytical and experimental results show that the developed mechanism has good performances in both decoupling ability and load capability;its static and dynamic performance can be precisely estimated from corresponding analytical *** proposed mechanism has wide potentials in precision positioning applic

摘要：The morphing trailing edge based compliant mechanism is a developing technology which can increase lift-drag ratio for variable flight modes by bending down the trailing *** material design is integrated into topology optimization for the morphing trailing edge based compliant mechanism in the paper.A two-step optimization strategy is established to solve the integrated design ***,lamination parameters are introduced and viewed as a bridge between structure stiffness and fiber angles for composite *** variables include the lamination parameters and element *** least-squares between actual and desired displacements at output points along trailing edge is adopted to evaluate the deformed capability of the trailing *** integrated optimization model for the composite morphing trailing edge is established with the volume *** optimal topologic shape and lamination parameters are initially ***,a least-squares optimization between fiber angles and the optimal lamination parameters is implemented to obtain optimal fiber ***,morphing capability of composites trailing edge based compliant mechanism is investigated by simulation and *** results indicate the composites trailing edge based compliant mechanism can approximately bend down 8 degrees and satisfies the design requirement.

摘要：In this paper, a method to design bird-strike-resistant aircraft structures is presented and illustrated through examples. The focus is on bird strike experiments and simulations. The explicit finite element software PAM-CRASH is employed to conduct bird strike simulations, and a coupled Smooth Particles Hydrodynamic（SPH） and Finite Element（FE） method is used to simulate the interaction between a bird and a target structure. The SPH method is explained, and an SPH bird model is established. Constitutive models for various structural materials, such as aluminum alloys, composite materials, honeycomb, and foam materials that are used in aircraft structures,are presented, and model parameters are identified by conducting various material tests. Good agreements between simulation results and experimental data suggest that the numerical model is capable of predicting the dynamic responses of various aircraft structures under a bird strike,and numerical simulation can be used as a tool to design bird-strike-resistant aircraft structures.

摘要：A gas liquid centrifugal separator is widely used in industry on account of its simple geometry and little maintenance. These separators have considerable advantages over filters, scrubbers or precipitators in term of compact design, lower pressure drop and higher capacity. A gas liquid centrifugal separator is a device that utilizes centrifugal forces and low pressure caused by rotational motion to separate liquid from gas by density differences. Efficient and reliable separation is required for the optimum operation. These separators are often operated at less than peak efficiency due to the entrainment of separated liquid through an outlet pipe which is closely associated with the very complicated flow phenomena involved. Design parameters such as length of the separation space, vane exit angle, inlet to outlet diameter ratio, models for separation efficiency and pressure drop as a function of physical dimensions are not available in literature. This leaves the designer with very little to go on except known designs and experimentation. The aim of present study is to perform a parametric study to get higher efficiency for gas-liquid separator. A parametric study has been carded out with the help of CFD tools to analyze a separation performance of a centrifugal separator by varying the length of separator space. The best design parameters are analyzed based upon obtained results, tangential velocities, vortices, total pressure losses. From the present study several attempts are made to improve the performance of conventional centrifugal separators.