Chen L.-B.,Qingdao Technological University |
Yang W.,Beijing Computational Science Research Center
Laser Physics Letters | Year: 2014
We propose a two-qubit optically controlled phase gate in quantum dot molecules via adiabatic passage and hole tunnelling. Our proposal combines the merits of the current generation of vertically stacked self-assembled InAs quantum dots and adiabatic passage. The simulation shows an implementation of the gate with a fidelity exceeding 0.98. © 2014 Astro Ltd.
Lan H.,Xi'an Jiaotong University |
Lan H.,Qingdao Technological University |
Ding Y.,Xi'an Jiaotong University
Nano Today | Year: 2012
Quantum dot (QD) arrays have now been attracting tremendous attention due to the potential applications in various high performance devices (e.g., QD lasers, 3rd generation solar cells, single photon emitters, QD memories, etc.), the fundamental investigation of quantum computing and quantum communication, and in the exploration or observation of novel physical phenomena. Uniform and regular QD arrays with precisely controlled positions and sizes may serve as a template for the next generation of nanoelectronic and optoelectronic devices. Currently, the major challenging issues in commercialized application of QD arrays include fabrication of large-area, defect-free, highly uniform and ordering QDs, accurate positioning for individual QD nucleation site, and reproducibility in size and spatial distribution, which all crucially determines optoelectronic performance and consistency for these QDs-based functional devices and the investigation of fundamental physical properties for QDs. Over the past decade, enormous attempts have been made to improve the ordering, positioning, uniformity, and defect reduction for obtaining perfect QD arrays over a large area with long range ordering. This article provides a review of some major attempts and progresses recently made for enhancing the ordering, positioning and uniformity for QD arrays, with an emphasis on the problems which has been well addressed to reach the current state of the arts. Furthermore, the prospects, challenges and trends for producing high quality QD arrays with high ordering, uniformity, positioning and defect reduction, are addressed. Finally, some potential or promising solutions for achieving perfect QD arrays are discussed. © 2012 Elsevier Ltd. All rights reserved.
Meng F.,Qingdao Technological University |
Zhang Q.,Beijing Institute of Technology |
Cheng H.,Qingdao Technological University
Knowledge-Based Systems | Year: 2013
In this paper, two new aggregation operators called the arithmetical interval-valued intuitionistic fuzzy generalized λ-Shapley Choquet (AIVIFGSCgλ) operator and the geometric interval-valued intuitionistic fuzzy generalized λ-Shapley Choquet (GIVIFGSC gλ) operator are proposed. These operators not only globally consider the importance of combinations or their ordered positions, but also overall reflect the correlations among combinations or their ordered positions. Based on the operational laws on interval-valued intuitionistic fuzzy values, the specific expressions of the AIVIFGSCgλ and GIVIFGSC gλ operators are given, which are also interval-valued intuitionistic fuzzy values. Meantime, some desirable properties are studied. Furthermore, two new approaches to multi-criteria group decision making under interval-valued intuitionistic fuzzy environment are proposed. Finally, a numerical example is provided to illustrate the developed procedures. © 2012 Elsevier B.V. All rights reserved.
Wang H.,Qingdao University |
Yang S.,Qingdao Technological University
Mechanical Systems and Signal Processing | Year: 2013
Noncircular pistons are becoming more and more popular in the automotive industry. The challenge of machining this kind of pistons (e.g., middle-convex and varying ellipse piston (MCVEP)), lies in the rigorous demand of the cutting feed mechanism for large force generation, high stiffness, fast response, long stroke and high accuracy. The conventional processing methods cannot meet the challenge so a new piezoelectric actuator (PEA) based fast tool servo (FTS) mechanism was developed to incorporate additional functions to a general CNC system that will facilitate the execution of MCVEP turning. Since the desired tool trajectories are approximately periodic signals in MCVEP turning, and the repetitive control can achieve asymptotic tracking and disturbance rejection of periodic signals, a plug-in repetitive control is designed to be added on the conventional PID controller. In the experiments, the designed prototype was used to machine a MCVEP for the gasoline engine, which was equipped with the PEA-based FTS system, as well as the plug-in repetitive controller. The machining test validated the effective of the designed noncircular turning system. © 2011 Elsevier Ltd. All rights reserved.
Meng D.,Qingdao Technological University |
Chen L.,Qingdao Technological University
Applied Ocean Research | Year: 2012
This paper presents a model formulation that can be used for analyzing the three-dimensional vibration behaviors of an inclined extensible steel catenary riser (SCR). The virtual work-energy functional, which involves strain energy due to axial stretching and bending rigidity of the riser and virtual work done by the gravitational, inertial and external drag forces, is formulated. The method of Galerkin finite element is used to obtain the mass and stiffness matrices. Then the eigenvalue problem is solved to determine its natural frequencies and corresponding mode shapes. A new nonlinear model capable of analyzing the vortex-induced vibration of SCR in the ocean current was addressed. The unsteady hydrodynamic forces associated with cross-flow vibrations are modeled as distributed van der Pol wake oscillators. Depending on the vortex-excited out-of-plane modes and system fluid-structure parameters, the parametric studies are carried out to determine the maximum response amplitudes of SCR, along with the occurrence of the mode transition phenomenon. The obtained results highlight the effect of internal fluid velocities and top tension on the nonlinear dynamics of riser undergoing vortex-induced vibration. © 2011 Elsevier Ltd.
Yang Z.,Qingdao Technological University
Computers and Mathematics with Applications | Year: 2011
This paper is concerned with the existence and multiplicity of positive solutions for the system of p-Laplacian boundary value problems -( (ui′)pi-1)′=fi(t, u1,⋯,un),ui(0)=ui′(1)=0,i=1, ⋯,n, where n2, pi>1, fi&C([0,1]×R+n, R+)(i=1,⋯,n,R+:=[0,∞)). Based on a priori estimates achieved by utilizing the Jensen integral inequalities and R+n-monotone matrices, we use fixed point index theory to establish the existence and multiplicity of positive solutions for the above problem. © 2011 Elsevier Ltd. All rights reserved.
Xu X.-K.,Qingdao Technological University
IEEE Transactions on Antennas and Propagation | Year: 2010
We exploit the joint fractal properties of sea clutter extracted from detrended fluctuation analysis (DFA) for targets detection. We find that two specific fractal statistics, i.e., the intercept at the crucial scale and the Hurst exponent of optimal scales provide valuable information for targets detection. The first statistic measures the discrepancy between sea clutter and low observable targets at the crucial fractal scale, and the second one evaluates the average fractal difference within the optimal multi-scales. A target detection method integrating these two statistics is proposed, which is validated by real-life IPIX radar datasets. We find that this joint fractal detection approach achieves more accurate results for low observable targets detection. © 2006 IEEE.
Qingdao Technological University | Date: 2013-11-11
The present invention relates to a nano fluid electrostatic atomizing controllable jet minimal lubricating for grinding system. A grinding system is provided with a corona charging nozzle, a nozzle body of the corona charging nozzle is connected with a liquid supply system and an air supply system, a high-voltage direct-current electrostatic generator at the lower part of the nozzle body is connected with the cathode of an adjustable high-voltage direct-current power supply, the anode of the adjustable high-voltage direct-current power supply is connected with a workpiece charging device, and the workpiece charging device is attached to the non-machined surface of the workpiece. Nano fluid which used as grinding liquid is fed into the corona charging nozzle through the liquid supply system, meanwhile, the air supply system feeds compressed air into the corona charging nozzle.
Qingdao Technological University | Date: 2012-08-14
A method for determining a seismic design for a structure includes setting performance objectives; inputting the performance objectives into a single degree of freedom system to carry out a simulation test; continuously adjusting the size of seismic waves applied to the system to determine a relationship between performance demand and the period of the structure under different performance objectives; obtaining a seismic demand spectrum curve between a seismic influence coefficient or a spectral accelation and displacement performance objective in the single degree of freedom system; analyzing the relationship between the base shear force and the displacement of the engineering structure; converting the relationship into the relationship between the capacity and the displacement in the single degree of freedom system; obtaining a capacity spectrum curve; comparing the capacity spectrum curve with the performance demand spectrum curve; and assessing the seismic capacity of the structure under different performance objectives.
Qingdao Technological University | Date: 2011-05-23
The present application relates to a full wafer nanoimprint lithography device comprises a wafer stage, a full wafer coated with a liquid resist, a demolding nozzle, a composite mold, an imprint head, a pressure passageway, a vacuum passageway and a UV light source. The present application also relates to an imprinting method using the full wafer nanoimprint lithography device comprises the following steps: 1) a pretreatment process; 2) an imprinting process; 3) a curing process; and 4) a demolding process. The device and the method can be used for high volume manufacturing photonic crystal LEDs, nano patterned sapphire substrates and the like in large scale patterning on the non-planar surface or substrate.