摘要：The geometric,electronic and optical properties of the graphene-like gallium nitride(GaN) monolayer paired with WS_2 or WSe_2 were studied systematically using the first-principles *** interacts with WS2 or WSe_2 via van der Waals interaction and all the most stable configurations of these two nanocomposites exhibit direct band gap ***,the type-Ⅱ heterojunctions are formed because the conduction band minimums and valence band maximums are respectively contributed by WS_2(or WSe_2) and *** imaginary parts of the dielectric function and the absorption spectra of the heterostructures were also calculated and the relatively improved optical properties were observed because of the new interband *** addition,the band offsets as well as the intrinsic electric fields resulting from the interlayer charge transfer indicate that the electron-hole pairs recombination can be effectively inhibited,which is conducive for the photocatalysis ***,the band gaps of the heterostructures can be modulated by applying biaxial strains and even shift away the conduction band edge potential from the H^+/H_2potential in a certain range,which further enhances the photocatalyst *** results indicate that GaN/WS2 or GaN/WSe_2 nanocomposites are good candidate materials for photocatalyst or photoelectronic applications.

摘要：Aiming at the shortcomings of traditional contact measurement methods such as low measurement efficiency,high cost and low accuracy,a non-contact optical measurement method based on the laser displacement sensor is *** to the relevant regulations of the coaxiality error evaluation standard and the structural characteristics of the compound gear shaft,we have designed and built a set of supporting software system as well as a hardware test *** this paper,the distance difference threshold and scale threshold methods are used to eliminate outlier *** least squares circle is selected to calculate the center of the circle and the minimum containment cylinder axis method is used as the reference axis of the composite gear *** by the standard step shaft calibration,the coaxiality error of the composite gear shaft can be measured to be within 0.01 mm in less than two *** range value of the multi-section measurement test is 0.065 *** average coaxiality error is∅0.476 mm.

摘要：engineering change management is a special form of problem solving where many rules must be followed to satisfy the requirements of product *** engineering change has great influence on the cycle and the cost of product development,it is necessary to anticipate design changes(DCs)in advance and estimate the influence effectively.A process simulation-based method for engineering change management is proposed incorporating multiple assessment ***,the change propagation model is established,which includes the formulation of change propagation influence,assessment score of DC *** the optimization process of DC solution is introduced based on ant colony optimization(ACO),and an optimization algorithm is detailed to acquire the optimal DC solution ***,a case study of belt conveyor platform is implemented to validate the proposed *** results show that changed requirement of product can be satisfied by multiple DC solutions and the optimal one can be acquired according to the unique characteristics of each solution.

摘要：The problems of attachment failure and detachment impact within gecko-like robots’ locomotion control are considered in this paper. A real-time foot-end force intelligent sensing module with integrated sensing and structure is developed to help the robot get the foot-end force information in time and realize stable locomotion in an uncertain environment. Firstly,a structure/sensing integrated elastomer based on a Maltese cross/cantilever beam structure is completed by designing and finite element analysis. Secondly,a real-time data acquisition and transmission system is designed to obtain the foot-end reaction force which is miniaturized and distributed. Thirdly,based on this system,a force sensor calibration platform is built to complete the calibration,decoupling,and performance testing of the sensing module. Finally,the experiment of single-leg attachment performance is carried out. The results indicate that the three-axis sensing module can detect robot’s weight,measure the reaction force with high precision and provide real-time force from robot’s foot end.

摘要：Heavy-load transfer robots are widely used in automobile production and machinery manufacturing to improve production *** order to meet the needs of large billet transfer,a 4-DOF transfer robot is designed in this paper,which consists of parallel four-bar *** Jacobian matrix referring to the mapping matrix from the joint velocity to the operating space velocity of the transfer robot can be solved by the differential-vector *** mean value of the Jacobian matrix condition number in the workspace is used as the global performance index of the robot velocity and the optimization *** constraint condition is established based on the actual working *** the linkage length optimization is carried out to decrease the length of the linkage and to increase the global performance index of *** total length of robot rods is reduced by 6.12%.The global performance index of velocity is improved by 45.15%.Taking the optimized rod length as the mechanism parameter,the distribution of the motion space of the transfer robot is ***,the results show that the proposed method for establishing the Jacobian matrix of the lower-mobility robot and for the optimization of the rods based on the velocity global performance index is accurate and *** workspace distribution of the robot meets the design requirements.

摘要：The visual inspection is an economical and effective method for welding. For measuring the feature sizes of grooves,a method based on line structured light is presented. Firstly,an adaptive algorithm to extract the subpixel centerline of structured light stripes is introduced to deal with the uneven width and grayscale distributions of laser stripes,which is based on the quadratic weighted grayscale centroid. By means of region-of-interest(ROI)division and image difference,an image preprocessing algorithm is developed for filtering noise and improving image quality. Furthermore,to acquire geometrical dimensions of various grooves and groove types precisely,the subpixel feature point extraction algorithm of grooves is designed. Finally, experimental results of feature size measuring show that the absolute error of measurement is 0.031—0.176 mm,and the relative error of measurement is 0.2%—3.6%.

摘要：The aim of this study is to find an optimal design for a distributed hybrid renewable energy system(HRES) for a residential house in the UK. The hybrid system, which consists of wind turbines, PV arrays, a biodiesel generator, batteries and converters, is designed to meet the known dynamic electrical load of the house and make use of renewable energy resources available locally. Hybrid Optimization Model for Electric Renewables(HOMER) software is used for this study. Different combinations of wind turbines, PV arrays, a biodiesel generator and batteries are evaluated and compared using the NPC(Net Present Cost) method to find the optimal solutions. The HRES is modeled, simulated and optimized using HOMER. The results showed that the wind-biodiesel engine-battery system was the best with the lowest NPC(USD 60254) and the lowest COE(Cost of Energy, USD 0.548/k Wh) while the second best system added PV arrays. This study gives evidence of the key contribution wind turbines make to HRES due to abundant wind resources in the UK, especially in Wales.

摘要：Electron beam lithography(EBL) is a key technology in the fabrication of nanoscale silicon optical waveguide. The influence of exposure dose, the main process parameter of EBL, on the structure profile of poly-methyl methacrylate(PMMA) after development was studied using a silicon on insulator(SOI) wafer with 220 nm top silicon as the substrate. The relationship between exposure dose and structure pattern width after development was analyzed according to the measurement results. The optimum exposure dose of 220 μC/cm^(2) was found to obtain a final structure consistent with the designed mask value through subsequent processes. At the same time, according to the image segmentation curve tracking technology, the contour extraction process of the dose test results was carried out, and the relationship among mask design value, exposure dose and two-dimensional roughness of boundary contour was analyzed, which can provide reference for the subsequent electron beam lithography of the same substrate material.

摘要：This paper proposes the continuous controller design method for quantum Shannon entropy, which can continuously drive the entropy to track a desired trajectory. We also analyzed the controllability of Shannon entropy in very short time interval. Simulations are done on five dimensional quantum system, which can verify the validation of the method.

摘要：Although the torso plays an important role in the movement coordination and versatile locomotion of mammals,the structural design and neuromechanical control of a bionic torso have not been fully *** this paper,a parallel mechanism is designed as a bionic torso to improve the agility,coordination,and diversity of robot *** mechanism consists of 6-degree of freedom actuated parallel joints and can perfectly simulate the bending and stretching of an animal’s torso during walking and *** overall spatial motion performance of the parallel mechanism is improved by optimizing the structural *** on this structure,the rhythmic motion of the parallel mechanism is obtained by supporting state *** neural control of the parallel mechanism is realized by constructing a neuromechanical network,which merges the rhythmic signals of the legs and generates the locomotion of the bionic parallel mechanism for different motion *** results show that the complete integrated system can be controlled in real time to achieve proper limb-torso *** coordination enables several different motions with effectiveness and good performance.