Efficient generation of two-dimensional cluster states in a cavity QED

We propose a scheme to achieve a kind of nontrivial multipartite pair-wise controlled phase operation in a cavity QED setup. The operation implemented is of geometrical nature and is not sensitive to the thermal state of the cavity. In particular, we have managed to avoid the conventional dispersive coupling so that high speed gate operation is achieved which is very important in view of decoherence. We show that this multipartite pair-wise controlled phase operation makes the generation of two-dimensional cluster states very efficient.

Optimization and verification of free flight separation similarity law in high-speed wind tunnel

Based on the similarity of separation time,a similarity law optimization method for high-speed weapon delivery test is derived.The typical separation state under wind load is simulated by the numerical method.The real separation data of aircraft,separation data of previous test methods,separation data of ideal wind tunnel test of previous methods,and simulation data of the proposed optimization method are obtained.A comparison of the data shows that the method proposed can improve the performance of tracking.Similarity law optimization starts with the development of motion equations and dynamic equations in the windless state to address the problems of mismatching between vertical and horizontal displacement,and to address the problems of separation trajectory distortion caused by insufficient gravity acceleration of the scaling model of existing light model.The ejection velocity of the model is taken as a factor/vector,and is adjusted reasonably to compensate the linear displacement insufficiency caused by the insufficient vertical acceleration of the light model method,so as to ensure the matching of the vertical and horizontal displacement of the projectile,and to improve the consistency between the test results of high-speed projection and the actual separation trajectory.The optimized similarity law is applicable to many existing free-throwing modes of high-speed wind tunnels.The optimized similarity law is not affected by the ejection velocity and hanging mode of the projectile.The optimized similarity law is suitable not only for the launching of the buried ammunition compartment and external stores,but also for the test design of projectile launching and gravity separation.

Aerodynamic/mechanism optimization of a variable camber Fowler flap for general aviation aircraft

A conventional Fowler flap is designed to improve the take-off and landing performances of an aircraft.Because the flight states of general aviation aircraft vary significantly.A Fowler flap with a double-sliding track has been designed,which is capable of changing airfoil camber while cruising and climbing as well as meeting low-speed performance requirements.The aerodynamic characteristics of the variable camber Fowler flap were studied by computational simulation,and cambering was found to be beneficial for improving the lift-to-drag ratio when the lift coefficient was larger than the critical value,below which decambering was more effective:this critical value differed somewhat under different conditions.Taking the mechanism into account,the take-off and landing configurations were optimized on the basis of the GA(W)-1 airfoil with a 30%chord Fowler flap.Compared with reference configuration,the maximum lift coefficient of optimized take-off configuration was increased by 6.6%as well as the stalling angle and the lift-to-drag ratio were increased by 1.3° and 7.58%,respectively.Moreover,the maximum lift coefficient of the optimized landing configuration was increased by 6.3%,and the stalling angle was increased by 1.1°;however,the nose-down pitching moment of both configurations increased.Similar results were attained on a general aviation aircraft wing/body combination.A 3D model of the variable-camber Fowler flap driving mechanism was established in a computer-aided design system,and the results showed that all design configurations could be achieved by the double-sliding track.