Browsing by Issue Date, starting with "2007-10-25"

Now showing 1 - 20 of 58845

Study of fluorescence enhancement of colloidal CdSe/ZnS quantum dots bound to hexadecylamine by single-molecule measurements
(2007-10-25)
Yuan, Chi-Tsu
;
Chou, Wu-Ching
;
Chen, Yueh-Nan
;
Chou, Jui-Wen
;
Chuuji, Der-San
Fluorescence enhancement of colloidal CdSe/ZnS quantum dots (QDs) by the binding of hexadecylamine (HDA) ligands was investigated at the single-QD level. The blinking behavior of individual CdSe/ZnS QDs can be dramatically modified by additional HDA ligands. Both the ratio of the mean on/off time lengths and the total number of emitted photons within the on-time duration can be enhanced, by factors of up to 2.8 and 13, respectively. Consequently, the blinking rate can be suppressed down to 18%. The fluorescence decay curve is closer to a single-exponential decay profile and has a longer measured lifetime. These results suggest that HDA ligands can further improve surface passivation.
Effect of plasma processing gas composition on the nitrogen-doping status and visible light photocatalysis of TiO2
(2007-10-25)
Chen, Chienchih
;
Bai, Hsunling
;
Chang, Chungliang
;
環境工程研究所
;
Institute of Environmental Engineering
The atmospheric pressure plasma enhanced nanoparticle synthesis (APPENS) process is applied to produce nitrogen (N) doped titania (TiO2) photocatalysts. With TTIP (titanium tetraisopropoxide; Ti(OC3H7)(4)) and water vapors as precursors, the effect of plasma and annealing gas composition on the N-doping status is identified by a cross comparison of the chemical shift of N atoms with those of Ti and O atoms. The activities of various types of N-doped photocatalysts are evaluated via the conversion of isopropyl alcohol (IPA). The results show that the N-doped TiO2 particles with O-x-Ti-N-y and -(NO) dopants are produced via N-2 plasma gas followed by air or N2 annealing gases. They have better visible and UV photocatalytic activities compared to the pure TiO2 photocatalysts prepared under O-2/Ar plasma and annealing gases. On the other hand, the N-doped TiO2 photocatalyst produced under N-2/O-2/Ar plasma gas and then annealed with pure N2 gas tends to have an additional dopant of -(NO2), but its photocatalytic activity is even worse than those of the pure TiO2 photocatalysts. The results reveal that the Ox-Ti-Ny and -(NO) dopants may have positive effects on the visible light photocatalytic activity while the -(NO2) dopant tends to have a negative effect on the visible light photocatalytic activity.
A transient model of PEM fuel cells based on a spherical thin film-agglomerate approach
(2007-10-25)
Chang, Shih-Ming
;
Chu, Hsin-Sen
;
機械工程學系
;
Department of Mechanical Engineering
The objective of this study is to investigate the transient behavior of a PEM fuel cell by using a one-dimensional, two-phase mathematical model. This model treats the catalyst layer as a spherical thin film-agglomerate. Effects of various transport parameter as well as other factors such as catalyst loading, gas diffusion layer thickness and liquid water permeability on the transient evolution of major model properties and cell performance are investigated in detail. Numerical results show that the evolution of ionic potential drop and oxygen consumption experience several steps before they reach steady state. The same situation can also be seen for the evolution of water saturation and current density. A detail inspection of these phenomena shows a close relation between these transport variables and cell performance. Parametric studies of other design factors' effects reveal there optimum values which lead to a greater current output during its evolution period. (c) 2007 Elsevier B.V. All rights reserved.
Real-time vibrational amplitude change in the ground and excited states of a quinoid thiophene induced by few-cycle pulses
(2007-10-25)
Wang, Zhuan
;
Kobayashi, Takayoshi
;
電子物理學系
;
Department of Electrophysics
Several vibrational modes impulsively excited by 6.7 fs pulses were observed in a quinoid thiophene. From the amplitude decay time and the phase of vibration, the modulation mechanism of the electronic transition by the wave packet motion is discussed and classified in terms of vibronic coupling. Modes with wavenumbers of 1343 and 1420 cm(-1) are attributed to the wave packet motions on the potential surface of the excited and ground state, respectively, and a mode with 1539 cm(-1) is due to those of both states. The apparent low-frequency modulation of these three modes is ascribed to the artificial interference effect in the calculation of the spectrogram. (C) 2007 Elsevier B.V. All rights reserved.
60GHz broadband 0/1-level RF-via interconnect for RF-MEMS packaging
(2007-10-25)
Wu, Wc.
;
Hsu, L. H.
;
Chang, E. Y.
;
Starski, J. P.
;
Zirath, H.
The RF-via interconnect structure front the 0- to the 1-level package for coplanar RF-MEMS devices packaging is evaluated. The 0/1-level interconnect structure was designed and optimised using the electromagnetic simulation tool. The structure was then successfully fabricated and characterised up to 67 GHz. The measured and simulated results show good agreement, demonstrating DC-to-60 GHz broadband interconnect performance through the two levels package with return loss below 15 dB and insertion loss within 0.6 dB.
肉慾化MV　挑戰觀眾尺度
(2007-10-28)
李怡萱
;
Department of Communication and Technology
;
傳播與科技學系
最近有越來越多的音樂錄影帶(簡稱mtv)，都朝向強調女性裸露身體，非常肉慾且露骨的手法，由此來討論這樣的現象
環保新時尚
(2007-10-28)
江柏廷
;
Department of Communication and Technology
;
傳播與科技學系
談談時尚新潮流：高科技未來感與環保做結合。
《十七青春遁走》－青春、掙扎
(2007-10-28)
謝佳慧
;
Department of Communication and Technology
;
傳播與科技學系
細膩的描述了一個17歲少年青春期的點點滴滴。
網路非法下載　各方觀點不同
(2007-10-28)
盧沛樺
;
Department of Communication and Technology
;
傳播與科技學系
從網際網路資源共享的角度，檢視大學生非法下載的行為是否能夠合理化？
《娛樂至死》－娛樂媒體
(2007-10-28)
呂伯芬
;
Department of Communication and Technology
;
傳播與科技學系
介紹書中精彩內容探討現今追求表像、歡樂和激情的電視時代。
《謀殺的解析》一切從死亡開始
(2007-10-28)
吳念慈
;
Department of Communication and Technology
;
傳播與科技學系
與其說這是一本推理小說，不如說它是臨床心理分析個案；一九○九年，佛洛伊德抵達紐約，展開畢生唯一的訪美之行，與此同時，一樁撲朔迷離的豪門少女連續殺人疑案，震驚了紐約市政府當局。這起懸案，當然是虛構，但其中夾雜了真實的歷史背景；作者還原二十世紀初曼哈頓的輝煌時期全景，在回顧歷史的同時，並追溯心理分析理論初現之時的景況，也一窺佛洛伊德與門徒卡爾‧榮格之間亦師亦敵的關係。
Che Guevara－叛逆至上
(2007-10-28)
鍾瑄
;
Department of Communication and Technology
;
傳播與科技學系
切格瓦拉Che Guevara何以成為年輕人心中永遠的革命偶像,商品化後的Che是否已經變質?
《進去，出來，結束》－荒誕卻又真實
(2007-10-28)
黃夙蓮
;
Department of Communication and Technology
;
傳播與科技學系
滿口不堪入耳的髒話，抽煙、酗酒、大麻樣樣都來，視一夜情與嫖妓為理所當然，暴力性侵害的情節無所不在……會寫出這樣驚世駭俗小說的布考斯基，被時代雜誌稱為「無賴的桂冠詩人」。這絕對不是一部甜美、歡樂的作品，然而在濃鬱深沉的文字下，卻充滿了戲劇張力，讓人忍不住想要繼續往下讀。這或許就是布考斯基的獨特的文字魅力吧。
劉千榕—芬蘭的交換學生生活
(2007-10-28)
鄭瑋津
;
Department of Communication and Technology
;
傳播與科技學系
傳播科技學系大四同學劉千榕，在大家享受著大學的自由和無憂無慮，她卻經歷了三年的辛苦，除了成績要維持在前兩名，還以高分通過新制托福iBT，終於完成心願，在芬蘭當一年的交換學生，辛苦過後的甜美果實是什麼滋味？
總編輯的話
(2007-10-28)
陳濡群
;
Department of Communication and Technology
;
傳播與科技學系
心得
球場靈魂
(2007-10-28)
林憶宏
;
Department of Communication and Technology
;
傳播與科技學系
棒球場的形形色色
PTT鄉民現象
(2007-10-28)
蔡昇峰
;
Department of Communication and Technology
;
傳播與科技學系
批踢踢實業坊(PTT)是國內最大的BBS站，創造出許多流行文化。在國外BBS已經是落伍的系統，但為什麼唯獨台灣BBS卻相當盛行，甚至造就PTT這樣具有文化影響力的BBS站？
林秀幸　孤獨下的真理嚮往
(2007-10-28)
謝甄芳
;
Department of Communication and Technology
;
傳播與科技學系
站在辦公室門口，第一個映入眼簾的是因黏膠脫落而歪斜的門牌，下方黏著歪七扭八的春聯。打開門一看，牆上貼滿了小女兒的繪畫作品，以及放滿雜物的沙發及辦公桌、擺放參差不齊書架……不知道的人大概以為這是哪位率性藝術家的工作室吧？這就是客家學院林秀幸老師不拘小節的一貫風格。
從蔡依林看當代美學現象
(2007-10-28)
張雅雯
;
Department of Communication and Technology
;
傳播與科技學系
從「看我七十二變」談起。
李阿屏:每個人都要把握當下
(2007-10-28)
鄧詠兒
;
Department of Communication and Technology
;
傳播與科技學系
交大僑外組李阿屏教官,分享對僑務工作的喜與悲