摘要：The influence of complicated interaction between the flow field and heat transfer in cooled turbines becomes more and more significant with the increasing turbine inlet temperature. However, classical through-flow methods did not take into account the influence of the interaction caused by air cooling. The aerodynamic design and cooling design of cooled turbines were carried out separately, and the iterations between the aerodynamic design and cooling design led to a long design period and raised the design cost. To shorten the design period and decrease the design cost, this paper proposes a concise aero-thermal coupled through-flow method for the design of cooled turbines, taking into account the influence of the complicated interaction between the flow field and heat transfer in cooled turbines. The governing equations, such as energy equation and continuity equation in classical through-flow method are re-derived theoretically by considering the historical influence of cooling with the same method that deals with viscous losses in this paper. A cooling model is developed in this method. The cooled blade is split into a number of heat transfer elements, and the heat transfer is studied element by element along both the span and the chord in detail. This paper applies the method in the design of a two-stage axial turbine, of which the first stator is cooled with convective cooling. With the prescribed blade temperature limitation and the knowledge of the flow variables of the mainstream at the turbine inlet, such as the total pressure, total temperature and mass flow rate, the convergence of the calculation is then obtained and the properties of the flow field, velocity triangles and coolant requirement are well predicted. The calculated results prove that the aero-thermal coupled through-flow method is a reliable tool for flow analysis and coolant requirement prediction in the design of cooled turbines.

摘要：We extend the method of searching “eigen-operator” of the square of the Schroedinger operator to the interaction picture, which not only helps to construct Hamiltonians of two kinds of parametric amplifiers but also leads to a new uncertainty relation regarding to the free Hamiltonian and the interacting Hamiltonian.

摘要：A novel mapping equivalent approach is proposed in this paper, which can be used for analyzing and realizing a memristor-based dynamical circuit equivalently by a nonlinear dynamical circuit with the same topologies and circuit parameters. A memristor-based chaotic circuit and the corresponding Chua＇s chaotic circuit with two output differentiators are taken as examples to illustrate this approach. Equivalent dynamical analysis and realization of the memristor-based chaotic circuit are performed by using Chua＇s chaotic circuit. The results indicate that the outputs of memristor-based chaotic circuit and the corresponding outputs of Chua＇s chaotic circuit have identical dynamics. The proposed approach verified by numerical simulations and experimental observations is useful in designing and analyzing memristor-based dynamical circuits.

摘要：A novel pure and N-doped waved-graphene electro-catalyst with various wavelengths for oxygen reduction reaction（ORR） is explored in acid medium based on the firstprinciples calculations. The associative and dissociative mechanism are both explored from the O_2 adsorption to the H_2 O formation step by step, from which the dissociative mechanism is likely the only way with an effective 4e-process. Furthermore, a very favorable and effective mechanism is proposed for the ORR process, which may provide a guideline on the design of new non-metal electro-catalysts.

摘要：Cooling water is an important part in a Spallation Neutron Source target cooling system, but the unstable vortexes at the exits of the slits between every two tungsten target slices have a negative impact on the stable running of the target system. We apply the field synergy principle for fluid flow to obtain the optimal flow field, which has a uniform velocity distribution without eddy, and then, optimize the geometrical structure of the cooling water flow channel based on the optimal flow field. The results show that when the cooling water flows in the optimized channel, the eddy sizes decrease, the time fluctuations of velocity and pressure almost vanish, and the volume flow rates of the cooling water in each parallel slit are uniform. Therefore, it effectively improves the running stability of the target system with the premise of satisfying the target heat load.

摘要：In this paper, we extend a novel unconstrained multiobjective optimization algorithm, so-called multiobjective extremal optimization （MOEO）, to solve the constrained multiobjective optimization problems （MOPs）. The proposed approach is validated by three constrained benchmark problems and successfully applied to handling three multiobjective engineering design problems reported in literature. Simulation results indicate that the proposed approach is highly competitive with three state-of-the-art multiobjective evolutionary algorithms, i.e., NSGA-11, SPEA2 and PAES. Thus MOEO can be considered a good alternative to solve constrained multiobjective optimization problems.

摘要：Tracking the process of fault growth in mechanical systems using a range of tests is important to avoid catastrophic failures, So, it is necessary to study the design for testability （DFT）. In this paper, to improve the testability performance of me- chanical systems for tracking fault growth, a fault evolution-test dependency model （FETDM） is proposed to implement DFT. A testability analysis method that considers fault trackability and predictability is developed to quantify the testability performance of mechanical systems. Results from experiments on a centrifugal pump show that the proposed FETDM and testability analysis method can provide guidance to engineers to improve the testability level of mechanical systems.

摘要：This paper presents a design for a self-powered radio frequency identification (RFID) tag with a thin film bulk acoustic reso- nating piezoelectric power supply (PPS), which can be used for portable remote temperature monitoring. We call this system a PPS-RFID for short. The RFID systems have been found to have many applications in the internet of things (IOT) in the past decade. But semi-active RFID tags require an onboard battery which limits their applications in many fields. For these reasons, our research focuses on power sources for the RFID tags. This paper emphasizes the circuit design and simulation of PPS. In our tests, 0.283 mW was generated by PPS at 1 Hz vibration by a 650 N impact force. The results showed that the integrated PPS could supply sufficient power for the designed PPS-RFID tag. The PPS-RFID tag can be widely used for temperature monitoring during mobile transport of perishable items such as medicines or food.

摘要：A storage system is the core of a computer,and plays an important role in the sustainable development of emerging strategic industries,such as artificial intelligence,big data,cloud computing,and the Internet of *** stack access is a major factor restricting the performance of data-intensive systems because of the increasing performance of processors and network devices.

摘要：This paper presents a novel observer-based control scheme for discrete-time piecewise affine systems based on a piecewise-quadratic Lyapunov function. The key issue addressed in this paper is that the currently active region of the system is unknown, and can not be inferred from the measured *** approximating polytopic operating regions by ellipsoids and using the singular value decomposition technique to treat the constraint of matrix equality, the suggested control method can be formulated as linear matrix inequalities (LMIs), and solved much more efficiently than existing methods which could be only cast as bilinear matrix inequalities. A numerical example is also given to verify the proposed approach.