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1.
Laser welding is an established manufacturing technology for a large variety of automotive applications due to its attractive properties such as low heat input, high precision and fast welding speed. Especially when welding high strength steels, which are dominantly used in today＇s car body construction, the low heat input by laser welding bears significant advantages with regard to the properties of the weld seam. The exploitation of the full application potential of laser welding in mass production requires an appropriate manufacturing concept and corresponding auxiliary technologies. The present paper demonstrates the integration of laser welding into the surrounding manu- facturing concepts by a modular setup with different levels of automation. This approach offers flexible solutions for individual needs thereby optimizing investment cost, labor cost and productivity. Recently available laser sources enable exceptionally high welding speed on thin gauged sheet metals but require efficient material handling con- cepts to utilize the full speed potential. Industrial concepts are presented offering efficient material handling and high process robustness for mass production welding. 相似文献
2.
TURAL DINCER Gvner AKDENIZ Ali Rlza 《美中教育评论》2008,5(12):54-59
There are many factors influence the level of students＇ achievement in education. Studies show that one of these factors is ＂learning approach of a student＂. Research findings generally have identified two approaches of learning： deep and surface. When a student uses the deep approach, he/she has an intrinsic interest in subject matter and is interested in ideas and conclusions to understand the subject matter. When a student employs the surface approach, he/she merely memorizes knowledge to pass any exam in school. The aim of this study is to determine learning approaches of science student teachers and to examine the relationships among the variables, such as level of students＇ class and gender. The sample of this study consists of 108 student teachers from the Science Education Program at Department of Primary Science Education in Karadeniz Technical University. Approaches to learning of science student teachers are assessed using the Revised Two-factor Study Process Questionnaire （R-SPQ-2F）, a scale developed by Biggs, et al （2001） consisting of 20 items on a 5 point Likert Scale. According to findings, science student teachers generally have deep learning approaches. Moreover, learning approaches of science student teachers have not changed related to gender. 相似文献
3.
Ruben Jans Ria Bollen 《美中教育评论》2008,5(7):36-40
Employees in technical firms, like garages, need more and more formations. Due to the very fast innovation in technology, lifelong learning is a real need for these labour forces. On the other hand, there are the needed formations very specialized and expensive. Another problem employers faced in these economical sectors in Western Europe is the lack of candidates. Also in secondary education schools, the wide interest for these formations is decreasing. One of the factors causes this problem is that schools don＇t have enough money for investing in new and high-tech machines. Therefore two interreg projects were submitted and approved for financing. Interreg is an initiative of the European Union meant for the permanent development of the ＂European Space＂. The third phase of interreg means enhancing the economic and social cohesion within the European Union. In this paper, we describe two successful projects, namely Autoweb and V@K, which try to help employers, employees, schools and students to keep up with the high-tech innovations with a workplace-based e-learning program. 相似文献
4.
Dennis Ping-Cheng Wang 《美中教育评论》2008,5(9):32-41
Movement activities can be used to integrate with any other curriculum in childhood education. The movements can inspire the sense of rhythmic concepts for children. This study aims at investigating how children can be motivated and inspired rhythmically by body movement through Dalcroze approach. In this research, the author revealed how physical movements can motivate children＇s potential sense of rhythm and inspire children＇s interest of musical rhythmic concepts learning. The study was conducted with 1000 primary school 6th grade students from twenty primary schools in Taipei, Taiwan. These 1000 6th grade students have the same age, same music syllabus and have equally same music training at their schools. The 1000 students were divided into two equal groups, one having different activities of body movements at school, and the other without. The different activities included tapping, swinging, clapping, turning, and stamping simple rhythms. The experiments consisted two parts which were rhythm dictation and improvisational skills. All the participants were equally given the pre-test and post-test as evidences of progress of the experiment, and the researcher then compared with the differences of the two tests of the two groups before and after the experiment to see if there were any progress in their learning of musical rhythms. The study lasted 6 months and consisted of three stages： observation, comparison, and analysis. The author observed and compared the two groups of students, analyzed the results and found out that the two groups demonstrated obvious differences in their degree of progress on learning of musical rhythms. 相似文献
5.
阮幼丽 《宁德师专学报(自然科学版)》2008,20(2):213-215
由于基础设施的限制,农村中学学生视野较窄,但他们所处的生活环境中生物资源丰富多彩．农村中学生物教学可利用得天独厚的自然资源,促进教学,激发学生的学习兴趣,引导学生更好地学习生物,认识生物资源与人们生活的密切关系,促进学生的资源保护意识,培养高尚的情操。 相似文献
6.
Darra Pace Diane Schwartz 《美中教育评论》2008,5(12):20-26
The inclusion of students with disabilities at the university is a relatively new occurrence in the field of special education. Although legislation in the United States has supported the acceptance of students with disabilities at the post-secondary level, it has only provided minimal support with the emphasis on the learner rather than the curriculum. Now we are looking for multiple ways for students to access learning and demonstrate mastery. Universal Design for Learning （UDL） is currently seen as a means to reconceptionalize curriculum. This study examines the experience of four professors and their effort to use a Classroom Performance System （CPS） as part of reformatting their courses using UDL. The Center for Applied Special Technology, CAST （2001） states that the goal of Universal Design for Learning is to develop teaching methods that enable all students with diverse learning needs, including those with disabilities and cultural differences, to have equal access to classroom curriculum. This paradigm shift echoes the move in special education from a deficit model to a minority rights model put forward by Hahn （1989）, and which is the basis of inclusive educational philosophy. Together inclusion and UDL create learning environments that strive to serve all students. This research describes the implementation of clickers as part of the CPS program in college courses in a special education teacher preparation program. The case study demonstrates how technology can provide access for all learners with positive outcomes such as increased participation and application of knowledge. It also illustrates some of the difficulties in making this pedagogical paradigm shift particularly in the use of technology, and the value of overcoming the existing barriers in place. 相似文献
7.
Christian Harteis Tina Koc Barbara Morgenthaler 《美中教育评论》2008,5(1):68-80
Intuition usually is defined as the capability to act or decide appropriately without deliberately and consciously balancing alternatives, without following a certain rule or routine, and possibly without awareness （Gigerenzer, 2007; Hogarth, 2001; Klein, 2003; Myers, 2002）. It allows action which is quick （e.g. reaction to a challenging situation） and surprising, in the sense that it is extraordinary in performance level or shape. This paper reports theories of intuition and their empirical evidence in the field of professional work. It aims at reporting the state of research on intuition, discussing the relevance of different approaches for analyzing work performance, and describing challenges for future empirical research in the domain of professional working life. 相似文献
8.
概念图在高中生物复习总结中应用的初探 总被引：1，自引：0，他引：1
陈敏 《宁德师专学报(自然科学版)》2008,20(1):92-94
高中生物复习课教学是师生双方从新的视角对所学知识进行系统梳理、深化、拓宽及灵活应用的教与学的过程．应用概念图可以有效地组织课程内容,激发学生自主构建生物学知识体系,使知识概括化、网络化,并能灵活地迁移． 相似文献
9.
YANG Xi-yao WU Yong-an 《美中教育评论》2008,5(9):50-54
The study was to investigate the vague words measurement across native and non-native English speakers and gender differences. Ninety-two students from the University of Oklahoma participated in this study by filling out an internet-based questionnaire on the vague words. The researchers put each of the thirty-two vague words in a context, or the same word put into different contexts. The participants were asked to rate the degree or the numerical value that they thought was the most appropriate in the context of the vague word. It was found that ten out of the thirty-two words had a significant difference across the native and non-native English speakers, and two of thirty-two words had a significant difference across genders. The word ＂fairly＂ showed the most significant difference interactions of language speaking by gender. 相似文献
10.
当今,大学生利用假期来到教学资源相对贫乏的偏远山区进行支教已成为大学生回报社会的途径之一。在支教逐渐被大众广泛接受的社会背景之下,提升支教项目的系统性和专业性就成为了更多支教团队追求的目标。本文将以中国地质大学(北京)学生英语专业支教实践为实例,从团队建设、前期备课、宣传工作、教学实践四个方面分析支教规范性建设的新思路,为大学生支教项目的进一步发展提出更好的实施方案。 相似文献
11.
12.
A combined numerical model of thermal field and the primary dendrite arm spacing （PDAS） was proposed to correlate the process parameters and PDAS in laser welding of Cu and A1. The solidification parameters simulated by the finite volume method with commercial software ANASYS FLUENT were applied in the PDAS model to predict the dendrite arm spacing of fusion zone. Dendrite was also examined by the metallographic method to validate the model. Results indicate that the calculated PDAS agrees with metallographic measurements reasonably, especially the Hunt model. PDAS increases apparently with increasing laser power while decreases slightly with increasing welding speed. Increasing laser power increases the secondary dendrite and increasing welding speed increases the microporosity in dendrite. 相似文献
13.
龚发兴 《宁德师专学报(自然科学版)》2008,20(1):86-88
提出关注化学教学情境创设,能培养学生创新和独立解决问题的能力,诱发学生创造想象的兴趣和动机,进而培养学生的变通能力,从而有效的提升教学效率． 相似文献
14.
蔡雀金 《宁德师专学报(自然科学版)》2008,20(1):77-79
新课标中明确指出评价是信息技术教学的重要组成部分,要把学生学习的过程评价与期末考试等总结性评价相结合,适度加大过程性评价在期末成绩评定中的比重．根据教学经验及新课标要求,就信息技术课程教学评价谈点滴体会． 相似文献
15.
Pushparajah Rajaguru Hua Lu Chris Bailey 《上海大学学报(英文版)》2014,(3):239-250
This paper presents mean fatigue lifetime predic- tion of a wire-bond structure model in power electronic module using a failure physics approach that integrates high fidelity modelling and reduced order modelling. Loading current with variable amplitudes is applied to a finite element model of simplified wirebond structures. The resulting accumulated fatigue damage due to random loads is predicted by using reduced order modelling based on failure physics, a cycle counting algorithm, and various nonlinear fatigue damage models widely used in the literature. The reduced order mod- elling approach based on failure physics uses prediction data for the electro-thermo-mechanical behaviour of the wire-bond design of a power module obtained through non-linear transient finite element simulations, in particular for the fatigue life-time of the aluminium wire attached to the silicon chip of the wire in the module. The reduced order models that capture the black box function of the accumulated plastic strain are used in pre- dicting the mean fatigue life time of the wire bond structure under random loads. One of the widely used cycle counting algorithms, rainflow counting algorithm, is used to count cycles of the temperature profile at the specific point of the wire bond structure in a power electronic module. The cycle data from the rainflow algorithm mean life time of the wire bond structure are predicted with various cumulative fatigue models. Non-linear cumulative fatigue models such as damage curve approach （DCA）, double linear damage rule （DLDR）, and double dam- age curve approach （DDCA）, and linear cumulative fatigue damage model such as Palmgren-Miner rule are used to predict the mean fatigue life of the wire bond structure, and the results are compared. 相似文献
16.
CHEN Dan-xia 《美中教育评论》2008,5(9):17-22
As the world becomes increasingly interdependent, mutual understanding becomes increasingly important. Therefore, it is essential that people strive for reductions in social distance on an international level. Study abroad is one of the ways to approach internationalization and promote understanding among different peoples and cultures. The research reported in this paper empirically explored the efficacy of a China study abroad program for reducing the degree of social distance between a group of American undergraduate students and the Chinese people in China. 相似文献
17.
凌美香 《宁德师专学报(自然科学版)》2007,19(1):97-100
如何充分发挥多媒体辅助教学的优势，将多媒体技术合理运用于中学生物教学，以取得最佳教学效果，是值得深入探讨的课题．在农村中学高中生物学教学过程中，对新授课、复习课以及实验课等3种课型教学进行了对照试验，认为对抽象知识教学及系统复习课运用多媒体手段效果较佳，但多媒体课件演示不能替代学生实验操作技能的训练． 相似文献
18.
Jin-Ke Yu ;Hong-Wei Li ;Qi-Jie Zhai ;Jian-Xun Fu ;Zhi-Ping Luo ;Hong-Xing Zheng 《上海大学学报(英文版)》2014,(4):353-357
In the present work, crystal structure and for- mation mechanism of the secondary phase in Heusler Ni- Mn-Sn-Co materials were investigated using X-ray dif- fraction, scanning/transmission electron microscopy and selected-area electron diffraction techniques. Experimental results showed that the secondary phase presented in both Ni44.1Mn35.1Sn10.8Co10 as-cast bulk alloy and melt-spun ribbon, possessing a face-centered cubic （fcc） NilTSn3-type structure. The secondary phase in the as-cast bulk alloy was resulted from a eutectic reaction after the formation of a primary dendritic flphase during cooling. However in the melt-spun rapidly solidified ribbon, the secondary phase was largely suppressed as nano-precipitates distributed along the grain boundaries, which was attributed to a divorced eutectic reaction. The secondary phase exhibited partial amorphous state due to high local cooling rate. 相似文献
19.
陈智华 《宁德师专学报(自然科学版)》2007,19(3):319-321
学生作为教学活动的主体，理应成为教研工作的参与者．根据“学生代表参与评课”和“师生交流会”开展教学研究的实践、总结与分析，探讨了学生参与教研的形式与效果，为学校教研工作的有效开展提供借鉴． 相似文献
20.
Riveting is one of the major joining methods used in assembly, and the robotic riveting has been grad- ually introduced into aircraft industry. In this paper, a method is presented for modeling and simulation of per- cussive robotic riveting. In percussive riveting, vibration always exists. When an impact force is employed, a forced vibration will be induced. If it resonates with a robot nat- ural frequency, the vibration will cause damage to the robot. The main content of this paper is divided into three parts. Firstly, a robot dynamic model is established to compute the driving torque for each joint. Secondly, vibration responses under impact are analyzed for the percussive riveting process. Thirdly, the effect of riveting on robot vibration is studied over the robot workspace. The purpose of this paper is to discuss the suitable regions for riveting where the robot vibration is very minimal. It is shown that based on the presented method an appropriate trajectory can be planned for robotic riveting. 相似文献