摘要：By using our computational fluid dynamic models, a new type of single engine capable of operating over a wide range of Mach numbers from subsonic to hypersonic regimes is proposed for airplanes, whereas traditional piston engines, turbojet engines, and scram engines work only under a narrower range of operating conditions. The new engine has no compressors or turbines such as those used in conventional turbojet engines. An important point is its system of super multijets that collide to compress gas for the transonic regime. Computational fluid dynamics is applied to clarify the potential of this engine. The peak pressure at the combustion center is over 2.5 MPa, while that just before ignition is over 1.0 MPa. The maximum power of this engine will be sufficient for actual use. Under the conditions of higher Mach numbers, the main intake passage located in front of the super multijet nozzles, takes in air more. That results in a ram or scramjet engine for supersonic and hypersonic conditions.

摘要：Uncertainty is inherent and unavoidable in almost all engineering systems. It is of essential significance to deal with uncertainties by means of reliability approach and to achieve a reasonable balance between reliability against uncertainties and system performance in the control design of uncertain systems. Nevertheless, reliability methods which can be used directly for analysis and synthesis of active control of structures in the presence of uncertainties remain to be developed, especially in non-probabilistic uncertainty situations. In the present paper, the issue of vibration con- trol of uncertain structures using linear quadratic regulator （LQR） approach is studied from the viewpoint of reliabil- ity. An efficient non-probabilistic robust reliability method for LQR-based static output feedback robust control of un- certain structures is presented by treating bounded uncertain parameters as interval variables. The optimal vibration con- troller design for uncertain structures is carried out by solv- ing a robust reliability-based optimization problem with the objective to minimize the quadratic performance index. The controller obtained may possess optimum performance un- der the condition that the controlled structure is robustly re- liable with respect to admissible uncertainties. The proposed method provides an essential basis for achieving a balance between robustness and performance in controller design ot uncertain structures. The presented formulations are in the framework of linear matrix inequality and can be carried out conveniently. Two numerical examples are provided to illustrate the effectiveness and feasibility of the present method.

摘要：The problem of active vibration control for uncertain linear structural systems with control forces input timedelay is investigated in this ***,the original structural equation is converted to a state-space model by utilizing the matrix ***,according to the obtained model and a special Lyapunov functional,a sufficient condition is achieved for the closed-loop system to be stable with a prescribed level of disturbance ***,in terms of solving these linear matrix inequalities（LMIs）,the state-feed controller is achieved to stabilize the structural system with the performance ‖z‖2<γ‖ω‖***,by introducing the rank-1 vector to describe the system uncertainties,the uncertain system description is obtained,and the stabilizing condition is extended to the uncertain ***,examples are given to show the effectiveness of the proposed methods.

摘要：The mechanical failure of solid oxide fuel cell(SOFC) components may cause cracks with consequences such as gas leakage,structure instability and reduction of cell lifetime.A comprehensive 3D model of the thermal stresses of an anode-supported planar SOFC is presented in this *** main objective of this paper is to get an interconnect optimized design by evaluating the thermal stresses of an anode-supported SOFC for different designs,which would be a new criterion for interconnect *** model incorporates the momentum,mass,heat,ion and electron transport,as well as steady-state *** from methane steam reforming and water-gas shift reaction were considered in our *** results examine the relationship between the interconnect structures and thermal stresses in SOFC at certain mechanical properties.A wider interconnect of the anode side lowers the stress *** simulation results also indicate that thermal stress of coflow design is smaller than that of counterflow,corresponding to the temperature *** study shows that it is possible to design interconnects for an optimum thermal stress performance of the cell.

摘要：This paper presents a novel design of minimalist bipedal walking robot with flexible ankle and split-mass balancing *** proposed approach implements a novel strategy to achieve stable bipedal walk by decoupling the walking motion control from the sideway balancing *** strategy allows the walking controller to execute the walking task independently while the sideway balancing controller continuously maintains the balance of the *** hip-mass carry approach and selected stages of walk implemented in the control strategy can minimize the efect of major hip mass of the robot on the stability of its *** addition,the developed smooth joint trajectory planning eliminates the impacts of feet during the *** this paper,the new design of mechanism for locomotion systems and balancing systems are *** additional degree of freedom introduced at the ankle joint increases the sensitivity of the system and response time to the sideway *** efectiveness of the proposed strategy is experimentally tested on a bipedal robot *** experimental results provide evidence that the proposed strategy is feasible and advantageous.

摘要：Heat exchangers are widely used in the process engineering such as the chemical industries, the petroleum industries, and the HVAC applications etc. An optimally designed heat exchanger cannot only help the optimization of the equipment size but also the reduction of the power consumption. In this paper, a new optimization approach called algorithms of changes (AOC) is proposed for design and optimization of the shell-tube heat exchanger. This new optimization technique is developed based on the concept of the book of changes (I Ching) which is one of the oldest Chinese classic texts. In AOC, the hexagram operations in I Ching are generalized to binary string case and an iterative process, which imitates the I Ching inference, is defined. Before applying the AOC to the heat exchanger design problem, the new optimization method is examined by the benchmark optimization problems such as the global optimization test functions and the travelling salesman problem (TSP). Based on the TSP results, the AOC is shown to be superior to the genetic algorithms (GA). The AOC is then used in the optimal design of heat exchanger. The shell inside diameter, tube outside diameter, and baffles spacing are treated as the design (or optimized) variables. The cost of the heat exchanger is arranged as the objective function. For the heat exchanger design problem, the results show that the AOC is comparable to the GA method. Both methods can find the optimal solution in a short period of time.

摘要：Role based access control is one of the widely used access control *** are investigations in the literature that use knowledge representation mechanisms such as formal concept analysis(FCA),description logics,and Ontology for representing access control ***,while using FCA,investigations reported in the literature so far work on the logic that transforms the three dimensional access control matrix into dyadic formal *** transformation is mainly to derive the formal concepts,lattice structure and implications to represent role hierarchy and constraints of *** this work,we propose a methodology that models RBAC using triadic FCA without transforming the triadic access control matrix into dyadic formal *** discussion is on two lines of *** present how triadic FCA can provide a suitable representation of RBAC policy and we demonstrate how this representation follows role hierarchy and constraints of RBAC on sample healthcare network available in the literature.

摘要：This paper presents experimentally-obtained data which can be of importance in the design procedure of engineering components made of 1.4057 （X 17CrNil 6-2; AISI 431） steel. In this manner, uniaxialy tests related to determine material mechanical properties and short-time creep behavior were performed. Based on the mentioned tests, ultimate tensile strength, 0.2 offset yield strength and modulus of elasticity at low and elevated temperatures were determined. Also, creep behavior of considered steel was tested for selected temperatures and selected stress levels. According to experimentally determined Charpy impact energy an assessment of fracture toughness was made.

摘要：Four ionic liquids （ILs）： 3-（diethoxyphosphoryl）propyl triphenylphosphinium hexafluorophosphate [Ph3PC3P（OEt）2][PF6] （IL-1）, 3-（ethoxyphenylphosphoryl）propyl triphenylphosphinium hexafluorophosphate [Ph3PC3PPh（OEt）][PF6] （IL-2）, 3-（diphenylphosphoryl）propyl triphenylphosphinium hexafluorophosphate [Ph3PC3P（Ph）2][PF6] （IL-3）, and 3-（diethoxyphosphoryl）propyl triphenylphosphinium bis（trifluoromethanesulfonyl）imide [Ph3PC3P（OEt）2][NTf2] （IL-4） were synthesized and characterized by IR and 31p, 1H, 13C NMR spectroscopy. The liquid-liquid extraction of neodymium（Ⅲ） by these phosphorus functionalized ionic liquids （PFILs） diluted with common room temperature ionic liquid 1-hexyl-3-methylimidazolium bis（trifluoromethylsulfonyl）imide [C6mim][NTf2] was studied. The extraction percentage of Nd（Ⅲ） was measured as a fimction of various parameters, such as the ini- tial pH of aqueous phase, equilibrium time, temperature, and concentration of PFIL extractant. The influence of the nature of diluents and salting-out reagents on extraction was also investigated. The results indicated that the extraction process was exothermical and the extraction percentage of Nd（Ⅲ） by IL-1 was the highest among the PFILs investigated. A possible metal complexation mechanism was proposed for the present PFIL/IL extraction system. And the loaded Nd（Ⅲ） ions by PFIL could be stripped completely from the ionic liquid phase by 1 mol/L nitric acid.

摘要：This paper presents the design of decentralized repetitive control （RC） for multi-input multi-output （MIMO） systems. An optimization method is used to obtain a RC compensator that ensures system stability and good tracking performance. The designed compensator is in the form of a stable, low order, and causal filter, in which the compensator can be implemented separately without being merged with the RC internal model. This will reduce complexity in the implementation. Simulation results and comparison study are given to demonstrate the effectiveness of the proposed design. The novelty of design is also verified in experiments on a 2 degrees of freedom （DOF） robot.