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1.
A review on high power SOFC electrolyte layer manufacturing using thermal spray and physical vapour deposition technologies 总被引：1，自引：0，他引：1
Pierre Coddet Han-lin Liao Christian Coddet 《上海大学学报(英文版)》2014,(3):212-221
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. 相似文献
2.
This paper presented an automatic gain control(AGC) circuit suitable for FM/cw ladar. The proposed architecture was based on two-stage variable gain amplifier(VGA) chain with a novel DC offset canceller circuit, which contained an improved Gilbert cell and a Gm-C feedback loop. To keep the VGA with a linearity in dB characteristic, an improved exponential gain control circuit was introduced. The AGC was implemented in 0.18 μm standard CMOS process. Simulation and measurement results verified that its gain ranged from-20 dB to 30 dB, and bandwidth ranged from 100 kHz to 10 MHz. Its power consumption was 19.8 mW under a voltage supply of 3.3 V. 相似文献
3.
Chi Wang Fang Zhang Shu-Bo Bi Xue-Qin Xia Ting-Ting Xu 《上海大学学报(英文版)》2014,(4):327-332
Fabrication method and device of ultra-small gradient-index （GRIN） fiber probe were investigated in order to explore the development of ultra-small probes for optical coherence tomography （OCT） imaging. The beam- expanding effect of no-core fiber （NCF） and the focusing properties of the GRIN fiber lens were analyzed based on the model of GRIN fiber probe consisting of single-mode fiber （SMF）, NCF and GRIN fiber lens. A stereo micro- scope based system was developed to fabricate the GRIN fiber probe. A fiber fusion splicer and an ultrasonic cleaver were used to weld and cut the fiber respectively. A con- focal microscopy was used to measure the dimensions of probe components. The results show that the sizes of probe components developed are at the level of millimeter. Therefore, the proposed experimental system meets the fabrication requirements of an ultra-small self-focusing GRIN fiber probe. This shows that this fabrication device and method can be employed in the fabrication of ultra- small self-focusing GRIN fiber probe and applied in the study of miniaturized optical probes and OCT systems. 相似文献
4.
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. 相似文献
5.
Wind turbines（WTs） are quite expensive pieces of equipment in power industry. Maintenance and repair is a critical activity which also consumes lots of time and effort, hence making it a costly affair. Carefully planning the maintenance based upon condition of the equipment would make the process reasonable. Mostly the WTs are equipped with some kind of condition monitoring device/system, which provides the information about the device to the central data base i.e., supervisory control and data acquisition（SCADA） data base. These devices/systems make use of data processing techniques/methods in order to detect and predict faults. The information provided by condition monitoring equipments keeps on recoding in the SCADA data base. This paper dwells upon the techniques/methods/algorithms developed, to carry out diagnosis and prognosis of the faults, based upon SCADA data.Subsequently data driven approaching for SCADA data interpretation has been reviewed and an artificial intelligence（AI） based framework for fault diagnosis and prognosis of WTs using SCADA data is proposed. 相似文献
6.
Quan Yu Kesheng Wang 《上海大学学报(英文版)》2014,(1):32-38
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. 相似文献
7.
Oyelami Olufemi Moses 《美中教育评论》2008,5(11):22-27
More recent motivational research focuses on the identification of effective techniques for enhancing instructional design and meeting the needs of diverse student populations （Wlodkowski R. J., 1981）. Learning-motivation researchers are applying some of the same theories and concepts found to be effective in industry to the development of motivational models that enhance the teaching-learning environment. One of such models is the Attention Relevance Confidence Satisfaction （ARCS） model of motivational design developed by John M. Keller （Small Ruth V., 2007）. The continuous improvement in handheld devices technologies has led to a new learning paradigm called mobile learning which involves the delivery of learning contents to learners utilizing mobile computing devices. Handheld devices, however, have constraints which limit their use for effective learning. Towards improving the effectiveness of mobile learning is a new mobile learning model proposed by Shih on which instructional designs for mobile learning can be based to facilitate mobile learning design and to achieve better mobile learning outcomes （Yushin E. Shih ＆ Dennis Mills, 2007）. Shih＇s model is based on Graphical User Interface （GUI）. This paper presents an enhanced Shih＇s model for effective mobile learning outcome in a university environment by making provision for instructional design to include online library search for both e-books and audio books using collaborative filtering algorithm to aid the search and posting and reading of testimonials about positive mobile learning outcomes so as to encourage other mobile learners. It also incorporates the use of Voice User Interface （VUI） to access the learning portal in order to overcome mobile devices interface limitations in addition to Graphical User Interface （GUI） proposed by Shih, so as to cater for the learning needs of the blind and the visually impaired. 相似文献
8.
Hirpa G. Lemu 《上海大学学报(英文版)》2014,(4):289-294
Manufacturing systems of the future highly demand that the product data are built into the product model, and smooth data transfer to other computer-aided technologies are enabled. Depending on the type of the manufacturing system, it is envisaged that virtual engi- neering （VE） technologies play a significant role in inte- grating the computer-based technologies involved in the product＇s life cycle. Simulations in a virtual world and exchange of real-time product or design data are among the benefits for today＇s global oriented manufacturing busi- ness. To highlight the significance of design as carrier of product data and the key role played by VE technologies to inter-link design, manufacturing and associated compo- nents, this paper presents an overview and analysis of the state-of-the-art VE technologies to indicate potential applications and future research directions. 相似文献
9.
In order to explore effective ways to develop Chinese English learners＇ communicative competence, this study first briefly reviews the advantages of communicative language teaching （CLT） method which widely practiced in the Western countries and analyzes in details its obstacles in Chinese classroom context. Then it offers guidelines for compromising the communicative approach with the traditional Chinese approach. Finally, it puts forward some principles and techniques for English teaching practice in the Chinese environment. 相似文献
10.
The capability automated warehouse in of a company to implement an an optimized way might be nowadays a crucial leverage in order to gain competitive advantage to satisfy the demand. The order picking is a warehouse function that needs to deal with the retrieval of articles from their storage locations. Merging several single customer orders into one, a picking order can increase efficiency of warehouse operations. The aim of this paper is to define throughout the use of ad-hoc genetic algorithm （GA） how better a warehouse can be set up. The paper deals with order batching, which has a major effect on efficiency of warehouse operations to avoid wastes of resources in terms of processes and to control possibility of unexpected costs in advance. 相似文献
11.
Andrew J. Mason Charles A. Bertram 《美中教育评论》2014,(12):873-879
Implementation of cognitive apprenticeship in an introductory physics lab group problem-solving exercise may be mitigated by epistemic views toward physics of non-physics science majors. Quantitative pre-post data of the Force Concept Inventory （FCI） and Colorado Learning Attitudes About Science Survey （CLASS） of 39 students of a first semester algebra-based introductory physics course, while describing typical results for a traditional-format course overall （g = ＋0.14）, suggest differences in epistemic views between health science majors and life science majors which may correlate with differences in pre-post conceptual understanding. Audiovisual data of student lab groups working on a context-rich problem and students＇ written reflections described each group＇s typical dynamics and invoked epistemic games. We examined the effects of framework-based orientation （favored by biology majors） and performance-based orientation （favored by computer science, chemistry, and health science majors） on pre-post attitude survey performance. We also investigated possible correlations of these orientations with individual quantitative survey results and with qualitative audiovisual data of lab groups＇ choice of epistemic games. 相似文献
12.
13.
Kok Siang Tan Ngoh Khang Goh 《美中教育评论》2008,5(11):28-36
Key to renewed concern on the affective domain of education （Fensham, 2007） and on school graduates＇ readiness for a world of work （DEST, 2008; WDA, 2006） is the student＇s inclination-to-reflect when engaged in a learning or problem-solving task. Reflective learning is not new to education （Dewey, 1933; Ellis, 2001）. Since the inclination-to-reflect may not be obvious even among adults at work （Seibert ＆ Daudelin, 1999）, how much more can we expect from school students？ This article presents part of a research on secondary school students＇ inclination-to-reflect when engaged in chemistry learning tasks. The instrument used is the three-part Chemistry Learning and Thinking Instrument （CLTI）. The first part seeks to characterize students＇ inclination-to-reflect while attempting chemistry learning tasks and the other parts aim to characterize their learning-thinking preferences in the subject. This article shares the construction of the learning tasks in the first part and how students＇ reflective responses to these tasks are encouraged, scored and analyzed. Since assessment is said to drive teaching and learning, an alternative form of assessment, such as these CLTI items, may help students become more reflective in their learning habits and hence mare adantable tn the world of work. 相似文献
14.
Review of the first principles calculations and the design of cathode materials for Li-ion batteries
Cathode materials are the most critical chal- lenge for the large scale application of Li-ion batteries in electric vehicles and for the storages of electricity. The first principles calculations play an important role in develop- ment and optimization of novel cathode materials. In this paper, we overview the first principles calculations of energy, volume change, band-gap, phase diagram, and Li- ion transport mechanism of cathode materials with an emphasis on the design of such materials. We also over- view the recent progress of data mining techniques and the high-throughput first principles calculations for the design and development of cathode materials. Finally, we preview the challenges and opportunities of this rapidly developing field. 相似文献
15.
A wideband dual-feedback low noise amplifier(LNA) was analyzed, designed and implemented using SiGe heterojunction bipolar transistor(HBT) technology. The design analysis in terms of gain, input and output matching, noise and poles for the amplifier was presented in detail. The area of the complete chip die, including bonding pads and seal ring, was 655 μm×495 μm. The on-wafer measurements on the fabricated wideband LNA sample demonstrated good performance: a small-signal power gain of 33 dB with 3-dB bandwidth at 3.3 GHz was achieved;the input and output return losses were better than-10 dB from 100 MHz to 4 GHz and to 6 GHz, respectively; the noise figure was lower than 4.25 dB from 100 MHz to 6 GHz; with a 5 V supply, the values of OP1 dB and OIP3 were1.7 dBm and 11 dBm at 3-dB bandwidth, respectively. 相似文献
16.
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. 相似文献
17.
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. 相似文献
18.
Min Jiang ;Li-Na Chen ;Jin He ;Guang-Yao Chen ;Chong-He Li ;Xiong-Gang Lu 《上海大学学报(英文版)》2014,(3):265-274
The study of controlled rolling/controlled cooling process parameters which affect the microstructure and mechanical properties of a novel pipeline steel has been optimized by the orthogonal experiment with four factors and three levels in this paper. However, the parameters of thermo-mechanical control process （TMCP） optimized by the Gleeble-3500 hot simulator could not satisfy performance requirements of the X100 pipeline steel. In order to improve the performance of this steel, the influence of finish cooling temperature （FCT） on the microstructure and property is studied in detail. It is found that, as this steel is thermo-mechanically treated by this set of parameters （the start heating temperature, finish rolling temperature （FRT）, FCT and cooling rate of 1,180 ℃, 810 ℃, 350 ℃ and 35 ℃/s, respectively）, the micro- structures are mainly composed of granular bainite （GB） and acicular ferrite （AF）. The effective grain sizes are below 20 μm; the steel reaches the optimal balance between the strength and the toughness; the yield strength is 695 MPa; the tensile strength is 768 MPa; the elongation is 16.6 %; the impact energy is 262 J at room temperature. All indexes could meet the requirements of X100 pipeline steel. 相似文献
19.
福州大学紫金矿业学院依据"由企业支持办学建设、参与办学过程、检验办学成效"的运行与管理机制的"紫金模式",确定本科生的第六学期教学活动在上杭教学实践基地运行,主要由"工程实践型"企业教师承担的专业必修课、选修课和专业实习与实践以及课程设计等组成。已经组建的一支热爱教学工作、理论基础扎实、实践经验丰富、熟悉教学管理要求的企业"工程实践型"教师团队,在各教学环节中发挥了重要的互补作用。企业培养环节下一步需要加大基地的软件实力建设,努力提高"工程实践型"教师的教学水平与教学研究能力,面对新一轮国家战略调整对地矿行业的冲击,不断拓展企业实践的方向与合作企业范围,保障人才培养质量与学生就业的广适性。 相似文献
20.
Jovani Castelan Daniel Fritzen 《美中教育评论》2014,(12):842-847
The propagation and full application of the three-dimensional （3D） computer-aided design （CAD） software by mechanical engineering and industrial design courses is a fact. However, many students find it difficult because they have not previously developed a spatial vision and do not understand the internal process of the software to build 3D models. This work aims at showing the image generation process on the computer screen, inducing the students to, mentally, generate 3D model projections, improving their spatial vision, and speeding up the process of interpreting orthogonal and isometric perspective views. 相似文献