Residual stress analysis and bow simulation of crystalline silicon solar cells     

Chih-Hung Chen  Hsuan-Teh Hu  Fu-Ming Lin  Hsin-Hsin Hsieh 《浙江大学学报(A卷英文版)》2017,18(1):49-58

The pressure to reduce solar energy costs encourages efforts to reduce the thickness of silicon wafers. Thus, the cell bowing problem associated with the use of thin wafers has become increasingly important, as it can lead to the cracking of cells and thus to high yield losses. In this paper, a systematic approach for simulating the cell bowing induced by the firing process is presented. This approach consists of three processes: (1) the material properties are determined using a nanoidentation test; (2) the thicknesses of aluminum (Al) paste and silver (Ag) busbars and fingers are measured using scanning electron microscopy; (3) non-linear finite element analysis (FEA) is used for simulating the cell bowing induced by the firing process. As a result, the bowing obtained using FEA simulation agrees better with the experimental data than that using the bowing calculations suggested in literature. In addition, the total in-plane residual stress state in the wafer/cell due to the firing process can be determined using the FEA simulation. A detailed analysis of the firing-induced stress state in single crystalline silicon (sc-Si), cast, and edge-defined film-fed growth (EFG) multi-crystalline silicon wafers of different thicknesses is presented. Based on this analysis, a simple residual stress calculation is developed to estimate the maximum in-plane principal stress in the wafers. It is also proposed that the metallization pattern, Ag busbars and fingers screen printed on the front of a solar cell, can be designed using this approach. A practical case of a 3-busbar Si solar cell is presented.  相似文献   

中国薯蓣属根状茎组系统分类的初步研究     

裴鉴  丁志遵  秦慧贞  舒璞  唐世蓉  张涵庆 《中国科学院研究生院学报》1979,17(3):61-72

   本文根据我国薯蓣属(Dioscorea L．)根状茎组(Sect.  Stenophora Uline)的外部形态特征、细胞染色体数、花粉形态、植物化学成分、地理分布等的规律，证明根状茎组是该属中的一个比较原始的自然类群：1．具横走的多年生地下根状茎，其它组是一年生或多年生的块茎；2．大部分是2倍体，其它组是多倍体；3．花粉粒单沟型，外壁纹饰网纹或颗粒条纹，其它组为双沟型，外壁纹饰网纹；4．含甾体皂甙元(steroidal sapogenin)，其它组不含。   我们的研究观察证明，N．N．TepaCNMeHKO根据R.Knuth系统(1924)提出的薯蓣皂甙元在该属中无分布规律的说法是无充分依据的。   本文讨论了某些组或种的划分及系统位置：取消sect.Illigerestrum Prain et Burk.；将马    肠薯蓣(D．simulans Prain et Burk．)改属根状茎组；触丝薯蓣(D．tentaculigera Prain et Burk.)应列入顶生翅组  (Sect．shannicorea Prain et Burk．)，  并提出了盾叶薯蓣  (D. zingiberensis  Wright)和穿龙薯蓣(D．nipponica Makino)种的划分和定名的意见。  相似文献   

The impacts of network centrality and self‐regulation on an e‐learning environment with the support of social network awareness          下载免费PDF全文

Jian‐Wei Lin  Hsieh‐Hong Huang  Yuh‐Shy Chuang 《British journal of educational technology : journal of the Council for Educational Technology》2015,46(1):32-44

An e‐learning environment that supports social network awareness (SNA) is a highly effective means of increasing peer interaction and assisting student learning by raising awareness of social and learning contexts of peers. Network centrality profoundly impacts student learning in an SNA‐related e‐learning environment. Additionally, self‐regulation behavior significantly influences online learning of students. However, exactly how network centrality and self‐regulation influence learning behavior and effectiveness in an e‐learning environment remains unclear. Therefore, this study investigates how both variables (ie, network centrality and self‐regulation) impact student learning in an SNA‐related e‐learning environment. Analytical results indicate that the student group with high‐level centrality and low‐level self‐regulation more significantly progresses in learning achievement than the other groups. The second finding shows the group also has the highest number of students asking for help, revealing they have the highest system utilization rate.  相似文献   

伞形科植物染色体数目报告   总被引：3，自引：0，他引：3  

潘泽惠  秦慧贞  吴竹君  袁昌齐  刘守炉 《中国科学院研究生院学报》1985,23(2):97-102

In the present paper, chromosome numbers are reported for 33 species and varieties of Chinese Umbelliferae which belong to 17 genera in the subfamily Api- oideae.  Chromosome number of each species is shown in Table I.  Eighteen countings are newly reported.  Chromatin bridges and fragments were observed at anaphase I in some materials.  It is suggested that the fertility reduction in some species is due to the chromosome aberrations.  相似文献   

云南蹄盖蕨属一新种和一新杂种     

谢寅堂  王中仁 《中国科学院研究生院学报》1989,27(2):155-157

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Challenges facing Chinese academic staff in a UK university in terms of language,relationships and culture     

Hui-hua Hsieh 《Teaching in Higher Education》2013,18(4):371-383

The recruitment of international academic staff is viewed as one of the strategies to internationalise the universities. International academic staff, however, usually encounter many challenges when in a foreign context. This study aims to investigate the challenges of Chinese academic staff teaching in the UK in terms of language, relationships and culture. Eight Chinese academic staff from three different disciplines in one UK university were interviewed. The interviews focused on three areas: their language abilities, socialisation patterns and ideas of pedagogy. It is hoped the study may help institutions, educators and scholars to consider this worthwhile issue as an area of study and provide better support to meet the needs of international academic staff.  相似文献   

The concept of neighborhood underlying the phonetic consistency effect in Chinese character recognition: A four-decade review and beyond     

Hsieh  Cheng-Yu  Lin  Wei-Chun  Li  Meng-Feng  Wu  Jei-Tun 《Reading and writing》2021,34(5):1225-1246

Research on the phonetic consistency effect in Chinese began in the 1980s. For nearly forty years, the consistency effect, as well as its implications for Chinese character recognition, has been frequently examined. This article presents the debate over the consistency effect in Chinese character recognition. While some research supported the involvement of prelexical phonology and sublexical processing based on the presence of consistency effects, others argued against these accounts by revealing three potential limitations, including the confounding of the task demand effect, the regularity effects and the frequency effect. A possible way to settle the debate is to shift focus to the top–down role of neighborhood characteristics underlying the consistency effect in Chinese character recognition.

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A preliminary study of multiple college admission criteria in Taiwan: the relationship among motivation,standardized tests,high school achievements,and college success     

Tzu-Ling Hsieh 《高等教育研究与发展》2019,38(4):762-779

ABSTRACT

A new college admission policy will be implemented in Taiwan in 2022. The purpose of this study was to understand the relationship between admission criteria and college success. Data was obtained from the Taiwan Higher Education Database; a sample size of 8443 students from 156 universities was used in this study. By using the structural equation model, this study tested a research model that included factors such as motivation, standardized test scores, high school achievements, and college success. The findings revealed that the General Scholastic Ability Test scores (in Chinese, English, Social Studies) and high school average academic grades are significantly associated with college success. A student’s motivation to complete a certain major can significantly predict the quality of student effort and influence college success. These findings highlight the importance of some admission criteria and provide practical implications for educational policy-makers, school administrators, students, and parents.  相似文献   

Exploring profiles of ideal high school mathematical teaching behaviours: perceptions of in-service and pre-service teachers in Taiwan     

Feng-Jui Hsieh  Qian Chen 《Educational studies》2018,44(4):468-487

This study explored and compared the perspectives of Taiwanese in-service and pre-service high school mathematics teachers regarding ideal teaching behaviours; the perspectives of a nationwide sample of students were taken as the baseline. Fourteen factors contributing to ideal teaching behaviours were identified through exploratory factor analyses. Nine factors, including idea explanation and speedy lecture, were rooted in traditional Chinese culture; five factors, including concrete representation and student activities, were influenced by Western cultures. Three teacher profiles were identified through k-means clustering analysis. The perspectives of in-service teachers were dominated by a painless meaning-emphasised profile; these teachers emphasised meaningful learning for students and avoided the fast pace and demanding requirements that can cause distress in students, whereas pre-service teachers were dominated by an all-round profile, revealing their openness to all factors. Compared with pre-service teachers, in-service teachers’ perspectives were more similar to those of students.  相似文献   

A Web-Based Virtual Microscopy Platform for Improving Academic Performance in Histology and Pathology Laboratory Courses: A Pilot Study     

Bai-Chin Lee  Sung-Tsang Hsieh  Yih-Leong Chang  Fen-Yu Tseng  Yu-Jung Lin  Yuh-Lien Chen  Shu-Huei Wang  Yu-Fong Chang  Yi-Lwun Ho  Yen-Hsuan Ni  Shan-Chwen Chang 《Anatomical sciences education》2020,13(6):743-758

Virtual microscopy (VM) has been utilized to improve students' learning experience in microscope laboratory sessions, but minimal attention has been given to determining how to use VM more effectively. The study examined the influence of VM on academic performance and teacher and student perceptions and compared laboratory test scores before and after VM incorporation. A total of 662 third-year students studying histology and 651 fourth-year students studying pathology were divided into two groups. The light microscopy (LM) group used a light microscope in 2014 and 2015, while the LM + VM group used the VM platform and a light microscope in 2016 and 2017. Four factors positively predict laboratory scores (R square, 0.323; P < 0.001): (i) the pathology course and test-enhanced learning, (ii) the VM platform and experience, (iii) medical students and lecture scores, and (iv) female students. The LM + VM group exhibited less score variability on laboratory examinations relative to their mean than the LM group. The LM + VM group was also associated with fewer failing grades (F grade; odds ratio, 0.336; P < 0.001) and higher scores (A grade; odds ratio, 2.084; P < 0.001) after controlling for sex, school, course, and lecture grades. The positive effect of the VM platform on laboratory test grades was associated with prior experience using the VM platform and was synergistic with more interim tests. Both teachers and students agreed that the VM platform enhanced laboratory learning. The incorporation of the VM platform in the context of test-enhanced learning may help more students to master microscopic laboratory content.  相似文献