A review on high power SOFC electrolyte layer manufacturing using thermal spray and physical vapour deposition technologies

Manufacturing of solid oxide fuel cell （SOFC） components remains nowadays a key point for the indus- trial development of this technology. Especially, the deposition of the dense electrolyte layer which is sand- wiched between the porous anode and the porous cathode is of paramount importance and thus focuses a lot of attention. Therefore, this paper considers and reviews recent developments concerning solid electrolyte layers manufacturing using thermal spray （TS） and physical vapour deposition （PVD） technologies.     

Wind turbine fault detection based on SCADA data analysis using ANN

Wind energy is one of the fast growing sources of power production currently, and there is a great demand to reduce the cost of operation and maintenance. Most wind farms have installed supervisory control and data acquisition （SCADA） systems for system control and logging data. However, the collected data are not used effectively. This paper proposes a fault detection method for main bearing wind turbine based on existing SCADA data using an artificial neural network （ANN）. The ANN model for the normal behavior is established, and the difference between theoretical and actual values of the parameters is then calculated. Thus the early stage of main bearing fault can be identified to let the operator have sufficient time to make more informed decisions for maintenance.     

Optimum calibration of a parallel kinematic manipulator using digital indicators

This paper presents a calibration method for parallel manipulators using a measurement system specially installed on an external fixed frame. The external fixed frame is important as an error reference for calibration in certain operations, such as in the configuration of a parallel manip- ulator functioning as a machine tool where the workpiece is fixed to a worktable. The pose of the end-effector is mea- sured using three digital indicators installed on the external fixed frame. To enable measurement, the end-effector is assumed to be a plane large enough that all digital indicators could touch. The error is defined as the difference between the theoretical and actual readings of the digital indicators. The geometric parameters of the parallel manipulator are optimized to minimize this error. This calibration method is low cost and feasible for compensating geometric parameter errors for a parallel manipulator. Optimal pose selection for the calibration is achieved using a swarm intelligence search algorithm. The method is implemented on a prototype of a six degrees-of-freedom （DOFs） Gough-Stewart platform constructed to function as a machine tool.     

CFD simulation of micro-particle trapping under water tweezers

In early research, capture and manipulation of particles were mainly achieved by means of light, electricity and plasma in micro-fabficaton and micro-assembly. A new method is proposed using micro-water jet to form water tweezers to capture solid particles and implement position control of micro-particles. This paper analyzes the basic prin- ciple of water tweezers, and the discrete element method and smoothed particle hydrodynamics method are employed to establish a solid-liquid coupling model used in analyzing the trapping mechanism. A flow field model is set up to simulate dynamic characteristic of water tweezers based on computa- tional fluid dynamics （CFD）. Selection of boundary conditions, initial guess, solver control and convergence strategies of the model are discussed. Velocity and pressure of streamline are predicted and discussed under certain input conditions. Simu- lation results demonstrate that it is an efficiently theoretical method to eventually trap solid particles by water tweezers.     

Effects of roller burnishing process parameters on surface roughness of A356/5%SIC composite using response surface methodology

In this study, a simple roller burnishing tool was made to operate burnishing processes on A356/5%SIC metal matrix composite fabricated by electromagnetic stir casting under different parameters. The effects of burnishing speed, burnishing force and number of burnishing passes on the surface roughness and tribological properties were measured. Scanning electron microscopy （SEM） graphs of the machined surface with PCD （insert-10） tool and roller burnished surface with tungsten carbide （WC） roller were taken into consider- ation to observe the surface finish of metal matrix composites. The mechanical properties （tensile strength, hardness, duc- tility） of A356/5%SIC metal matrix composites were studied for both unburnished samples and burnished samples. The results revealed that the roller burnished samples of A356/ 5%SIC led to the improvement in tensile strength, hardness and ductility. In order to find out the effects of roller bur- nishing process parameters on the surface roughness of A356/ 5%SIC metal matrix composite, response surface methodol- ogy （RSM） （Box-Behnken design） was used and a prediction model was developed relevant to average surface roughness using experimental data. In the range of process parameters, the result shows that roller burnishing speed increases, and surface roughness decreases, but on the other hand roller burnishing force and number of passes increase, and surface roughness increases. Optimum values of burnishing speed （1.5 m/s）, burnishing force （50 N） and number of passes （2） during roller burnishing of A356/5%SIC metal matrix com- posite to minimize the surface roughness （predicted 1.232 μm） have been found out. There was only 5.03% error in the experimental and modeled results of surface roughness.     

A hybrid point cloud alignment method combining particle swarm optimization and iterative closest point method

3D quality inspection is widely applied in many industrial fields including mould design, automotive and blade manufacturing, etc. A commonly used method is to obtain the point cloud of the inspected object and make a comparison between the point cloud and the corresponding CAD model or template. Thus, it is important to align the point cloud with the template first and foremost. Moreover, for the purpose of automatization of quality inspection, this alignment process is expected to be completed without manual interference. In this paper, we propose to combine the particle swarm optimization （PSO） with iterative closest point （ICP） algorithm to achieve the automated point cloud alignment. The combination of the two algorithms can achieve a balance between the alignment speed and accuracy, and avoid the local optimal caused by bad initial position of the point cloud.     

我国“校本课程开发”话语演变及问题分析

在我国,"校本课程开发"实际上存在两套话语:课程政策话语与学术界主流话语。当前政策话语淡化而主流学术话语主导已成基本事实。我国校本课程开发理论话语由西方引入、转化而来,而基于本土课程开发实践的研究严重不足,由主流学术话语指导的中小学校本课程开发实践,在全国范围内基本陷入凌空踏虚、难以落实的尴尬。校本课程开发再概念化,从多维度拓展校本课程开发概念内涵,恰与政策话语神合,是一种立足现实,可以不断推进的校本课程开发策略。     

《鲁颂·閟宫》“新庙”考论

《诗经·鲁颂·閟宫》末章云:"松桷有舄,路寝孔硕,新庙奕奕。"历来的研究者在"新庙"所指为何的问题上歧见纷纭。从此诗内容出发,结合《左传》僖公年间的记载,并参照考古资料,可知"新庙"并非闵公庙或僖公庙,亦非姜嫄庙,而是指鲁僖公在位晚期重新修建的宗庙建筑,起因是僖公二十年鲁国西宫发生的火灾,建成时间约在僖公二十八年至僖公三十三年之间。     

层次分析法在ESP教材实效性评价中的应用

为探讨ESP教材在教学过程中的实效,结合专业特点和ESP特点,建立ESP教材实效评价模型,采用层次分析法,评价不同ESP教材中不同评价指标的实效,并以物理专业三种ESP教材为例进行模型验证,为教师进一步科学合理设计、编写和选择教材提供参考.     

唐代墓志中“举大事”考辨

以洛阳出土的唐代景教石刻《幢记》中的“举大事”为引子,结合唐代墓志中的其它语料,从语言学的角度进行考察,梳理出“举大事”的词义演变过程,得出“举大事”有“定葬”义,并揭示其内在的文化意义。