In engineering classes, there are seldom some writing essays for students to finish, especially for first-year students who just begin their courses. However, in MLE tutorials, I do meet some difficulties in writing for some questions. After reading the questions asking for explanations to some phenomena, I sometimes just get lost. In these cases, I just get rough ideas about answers, which means I do not know exact terminologies associated with the answers. As a result, my answers are wordy and not accurate. For example, one question was that “Explain why no hole is generated by the electron excitation involving a donor impurity atom.” The rough idea was that this electron was associated with a foreign atom and thus no hole was created. However, this rough was not suitable for answering, as it was somewhat oral. After I looked through the PPT slides, I got the answer: each electron was excited from an impurity level, and no corresponding hole was created within the valence band. The key words are donor electron and hole in the valence band.
To solve this kind of problems, I think I should focus on the following points. Firstly, I should listen to lectures carefully and try to get key words and critical points. Secondly, I had better go through the textbooks and memorize important terminologies and concepts. Last, I would pay special attention to my learning in English language and especially the aspects on how to express ideas in a concise and precise way. All in all, English plays an important role in learning, especially for us international students whose first language is not English. Studying textbooks written in English and writing in English are quite challenging for us.
Sunday, October 5, 2008
Summary of MIT opens new 'window' on solar energy
Summary of MIT opens new 'window' on solar energy
MIT researchers come up with an innovative work on solar energy recently. This work makes it possible that light is gathered over a large area like a window and then concentrated on edges to produce energy. This innovative work involves a mixture of two or more dyes painted onto a plane of glass or plastic. The dyes work together to absorb the light of different light wavelengths, reemit the light and transport it to the solar cells at the edges. The process indicates that it is enough for solar cells to just cover the edges, which decreases the cost dramatically. Moreover, according to the researchers, the focused light increases the electrical power obtained from each solar cell. All in all, the advantage of this work is the increases in efficiency and decreases in costs. By contrast, currently solar cells have to cover the whole roof to gather solar energy, which at the same time increases the difficulties of deploying and maintaining them. (Thomson, E.A, July 10, 2008)
Actually the similar idea about adding dyes into glass or plastic initially came up in the 1970s. However, the idea was abandoned later because little light reached the solar cells at the edges and much of it lost in the transportation. The engineers in MIT in optical techniques developed for organic light-emitting diodes and lasers. Some researchers came up with applying these advanced techniques in solar energy. The result was that they succeeded in making such suitable dyes added to glass that can collect and transport light. This revolutionary work will bring great benefits to human beings especially faced with shortage of resources and global warming. Realizing this work’s great potential, some researchers are starting a company to develop and commercialize this technology. They believe it will be widely spread within three years because the system is easy to build and run.
References: Thomson, E.A, July 10, 2008. MIT opens new ‘window’ on solar energy. From http://web.mit.edu/newsoffice/2008/solarcells-0710.html
MIT researchers come up with an innovative work on solar energy recently. This work makes it possible that light is gathered over a large area like a window and then concentrated on edges to produce energy. This innovative work involves a mixture of two or more dyes painted onto a plane of glass or plastic. The dyes work together to absorb the light of different light wavelengths, reemit the light and transport it to the solar cells at the edges. The process indicates that it is enough for solar cells to just cover the edges, which decreases the cost dramatically. Moreover, according to the researchers, the focused light increases the electrical power obtained from each solar cell. All in all, the advantage of this work is the increases in efficiency and decreases in costs. By contrast, currently solar cells have to cover the whole roof to gather solar energy, which at the same time increases the difficulties of deploying and maintaining them. (Thomson, E.A, July 10, 2008)
Actually the similar idea about adding dyes into glass or plastic initially came up in the 1970s. However, the idea was abandoned later because little light reached the solar cells at the edges and much of it lost in the transportation. The engineers in MIT in optical techniques developed for organic light-emitting diodes and lasers. Some researchers came up with applying these advanced techniques in solar energy. The result was that they succeeded in making such suitable dyes added to glass that can collect and transport light. This revolutionary work will bring great benefits to human beings especially faced with shortage of resources and global warming. Realizing this work’s great potential, some researchers are starting a company to develop and commercialize this technology. They believe it will be widely spread within three years because the system is easy to build and run.
References: Thomson, E.A, July 10, 2008. MIT opens new ‘window’ on solar energy. From http://web.mit.edu/newsoffice/2008/solarcells-0710.html
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