Browsing by Issue Date, starting with "2015-12-18"

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Cooperativity and Site-Selectivity of Intramolecular Hydrogen Bonds on the Fluorescence Quenching of Modified GFP Chromophores
(2015-12-18)
Chang, Deng-Hsiang
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Ou, Chun-Lin
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Hsu, Hung-Yu
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Huang, Guan-Jhih
;
Kao, Chen-Yi
This paper provides the first example of experimentally characterized hydrogen-bond cooperativity on fluorescence quenching with a modified green fluorescence protein (GFP) chromophore that contains a 6-membered C=N center dot center dot center dot H-O and a 7-membered C=O center dot center dot center dot H-O intramolecular H-bonds. Variable-temperature H-1 NMR and electronic absorption and emission spectroscopies were used to elucidate the preference of intra- vs intermolecular H-bonding at different concentrations (1 mM and 10 mu M), and X-ray crystal structures provide clues of possible intermolecular H-bonding modes. In the ground state, the 6-membered H-bond is significant but the 7-membered one is rather weak. However, fluorescence quenching is dominated by the 7-membered H-bond, indicating a strengthening of the H-bond in the excited state. The H-bonding effect is more pronounced in more polar solvents, and no intermediates were observed from femtosecond fluorescence decays. The fluorescence quenching is attributed to the occurrence of diabatic excited-state proton transfer. Cooperativity Of the two intramolecular H-bonds on spectral shifts and fluorescence quenching is evidenced by comparing with both the single H-bonded and the non-H-bonded counterparts. The H-bond cooperativity does not belong to the conventional patterns of sigma- and pi-cooperativity but a new type of polarization interactions, which demonstrates the significant interplay of H-bonds for multiple H-bonding systems in the electronically excited states.
Diffusion of a massive particle in a periodic potential: Application to adiabatic ratchets
(2015-12-18)
Rozenbaum, Viktor M.
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Makhnovskii, Yurii A.
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Shapochkina, Irina V.
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Sheu, Sheh-Yi
;
Yang, Dah-Yen
We generalize a theory of diffusion of a massive particle by the way in which transport characteristics are described by analytical expressions that formally coincide with those for the overdamped massless case but contain a factor comprising the particle mass which can be calculated in terms of Risken's matrix continued fraction method (MCFM). Using this generalization, we aim to elucidate how large gradients of a periodic potential affect the current in a tilted periodic potential and the average current of adiabatically driven on-off flashing ratchets. For this reason, we perform calculations for a sawtooth potential of the period L with an arbitrary sawtooth length (l < L) instead of the smooth potentials typically considered in MCFM-solvable problems. We find nonanalytic behavior of the transport characteristics calculated for the sharp extremely asymmetric sawtooth potential at l -> 0 which appears due to the inertial effect. Analysis of the temperature dependences of the quantities under study reveals the dominant role of inertia in the high-temperature region. In particular, we show, by the analytical strong-inertia approach developed for this region, that the temperature-dependent contribution to the mobility at zero force and to the related effective diffusion coefficient are proportional to T-3/2 and T-1/2, respectively, and have a logarithmic singularity at l -> 0.
In-Situ Probing Plasmonic Energy Transfer in Cu(In, Ga)Se-2 Solar Cells by Ultrabroadband Femtosecond Pump-Probe Spectroscopy
(2015-12-18)
Chen, Shih-Chen
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Wu, Kaung-Hsiung
;
Li, Jia-Xing
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Yabushita, Atsushi
;
Tang, Shih-Han
In this work, we demonstrated a viable experimental scheme for in-situ probing the effects of Au nanoparticles (NPs) incorporation on plasmonic energy transfer in Cu(In, Ga)Se-2 (CIGS) solar cells by elaborately analyzing the lifetimes and zero moment for hot carrier relaxation with ultrabroadband femtosecond pump-probe spectroscopy. The signals of enhanced photobleach (PB) and waned photoinduced absorption (PIA) attributable to surface plasmon resonance (SPR) of Au NPs were in-situ probed in transient differential absorption spectra. The results suggested that substantial carriers can be excited from ground state to lower excitation energy levels, which can reach thermalization much faster with the existence of SPR. Thus, direct electron transfer (DET) could be implemented to enhance the photocurrent of CIGS solar cells. Furthermore, based on the extracted hot carrier lifetimes, it was confirmed that the improved electrical transport might have been resulted primarily from the reduction in the surface recombination of photoinduced carriers through enhanced local electromagnetic field (LEMF). Finally, theoretical calculation for resonant energy transfer (RET)-induced enhancement in the probability of exciting electron-hole pairs was conducted and the results agreed well with the enhanced PB peak of transient differential absorption in plasmonic CIGS film. These results indicate that plasmonic energy transfer is a viable approach to boost high-efficiency CIGS solar cells.
在地青年返鄉　深耕苗栗
(2015-12-20)
許雅筑
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Department of Communication and Technology
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傳播與科技學系
「老家，屬於每一個人的家。」短短一句經營理念，道出陳鵬文對家鄉人文的眷戀與情分。
台灣高等教育　本質流失
(2015-12-20)
曾煥富
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Department of Communication and Technology
;
傳播與科技學系
台灣教育本質上，擁有內容上的不健全與矛盾。
台灣高教敲警鐘
(2015-12-20)
王雪琪
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Department of Communication and Technology
;
傳播與科技學系
台灣高等教育所面對的危機，主因是不是少子化造成的？
MOOCs熱潮　高教危機轉機
(2015-12-20)
許馨仁
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Department of Communication and Technology
;
傳播與科技學系
我國於二〇一四年提出「磨課師分項計畫」，引進西方MOOC數位學習模式。政策施行至今，產生不少爭議。
總編輯的話
(2015-12-20)
吳和謙
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Department of Communication and Technology
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傳播與科技學系
本期為喀報第兩百三十一期，共有十二篇稿件。類目以社會議題為主，相當充實，側欄廣告則以即將到來的聖誕節為主題，溫馨動人。
長青生活　樂齡演出
(2015-12-20)
何佳頴
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Department of Communication and Technology
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傳播與科技學系
國立臺南生活美學館舉辦成果發表會，展現長青生活的活力與價值。
媽寶　大學新課題
(2015-12-20)
唐宜嘉
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Department of Communication and Technology
;
傳播與科技學系
各大專院校於十月份召開新生家長座談會，出現許多媽寶大學生與寶媽家長，激起社會大眾的關注與討論。
靠山
(2015-12-20)
翁世樺
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Department of Communication and Technology
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傳播與科技學系
我的父親與他的父親。
消費革命　無現金時代
(2015-12-20)
徐義薇
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Department of Communication and Technology
;
傳播與科技學系
從第三方支付平台與行動支付新型態，借鏡國外探討台灣現今電子商務的發展。
手作甜　填胃也甜心
(2015-12-20)
薛如真
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Department of Communication and Technology
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傳播與科技學系
甜點能帶來幸福的感受，而甜點師為人們製造幸福。
當個實況主　分享遊戲喜悅
(2015-12-20)
蔡佳珊
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Department of Communication and Technology
;
傳播與科技學系
魯蛋在二〇一一年開始接觸實況，並因為一款遊戲一夕成名。
少女的生活食譜
(2015-12-20)
孔婉寧
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Department of Communication and Technology
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傳播與科技學系
黃愛然，仍是藝術大學的學生，用甜點創立粉絲專頁，建立廣大的粉絲。
老有所養　臺灣做得怎樣
(2015-12-20)
竇玉帥
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Department of Communication and Technology
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傳播與科技學系
對臺灣三百萬老年人口來說，最牽腸掛肚的問題便是如何養老。
Black hole remnant in asymptotic anti-de Sitter space
(2015-12-21)
Wen, Wen-Yu
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Wu, Shang-Yu
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電子物理學系
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Department of Electrophysics
The solution of a remnant was suggested for the black hole ground state after surface gravity is corrected for the loop quantum effect. On the other hand, a Schwarzschild black hole in asymptotic anti-de Sitter space would tunnel into the thermal soliton solution known as the Hawking-Page phase transition. In this letter, we investigate the low temperature phase of a three-dimensional Banados-Teitelboim-Zanelli (BTZ) black hole and four-dimensional AdS Schwarzschild black hole. We find that the thermal soliton is energetically favored rather than the remnant solution at low temperature in three dimensions, while a Planck-size remnant is still possible in four dimensions. Though the BTZ remnant seems energetically disfavored, we argue that it is still possible to find in the overcooled phase if strings were present, and its implication is discussed.
A stochastic simulation method for the assessment of resistive random access memory retention reliability
(2015-12-21)
Berco, Dan
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Tseng, Tseung-Yuen
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This study presents an evaluation method for resistive random access memory retention reliability based on the Metropolis Monte Carlo algorithm and Gibbs free energy. The method, which does not rely on a time evolution, provides an extremely efficient way to compare the relative retention properties of metal-insulator-metal structures. It requires a small number of iterations and may be used for statistical analysis. The presented approach is used to compare the relative robustness of a single layer ZrO2 device with a double layer ZnO/ZrO2 one, and obtain results which are in good agreement with experimental data. (C) 2015 AIP Publishing LLC.
交大e-News第200期-頒授廣達電腦梁次震副董事長、翁山蘇姬女士名譽博士學位
(2015-12-21)
國立交通大學秘書室
;
Secretariat
A stochastic simulation method for the assessment of resistive random access memory retention reliability
(2015-12-21)
Berco, Dan
;
Tseng, Tseung-Yuen
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This study presents an evaluation method for resistive random access memory retention reliability based on the Metropolis Monte Carlo algorithm and Gibbs free energy. The method, which does not rely on a time evolution, provides an extremely efficient way to compare the relative retention properties of metal-insulator-metal structures. It requires a small number of iterations and may be used for statistical analysis. The presented approach is used to compare the relative robustness of a single layer ZrO2 device with a double layer ZnO/ZrO2 one, and obtain results which are in good agreement with experimental data. (C) 2015 AIP Publishing LLC.