Browsing by Issue Date, starting with "2015-11-24"

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Precise Synthesis of New Exactly Defined Graft Copolymers Made up of Poly(alkyl methacrylate)s by Iterative Methodology Using Living Anionic Polymerization
(2015-11-24)
Ito, Shotaro
;
Ishizone, Takashi
;
Hirao, Akira
;
應用化學系
;
Department of Applied Chemistry
An iterative methodology using living anionic polymerization with a 1,1-diphenylethylene disubstituted with trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBS) ethers has been developed in order to synthesize new exactly defined graft copolymers made up of poly(alkyl methacrylate)s. During each reaction sequence, the TMS and TBS ethers were transformed into alpha-phenyl acrylate (PA) functions one by one at the different reaction stages. The first PA function derived from the TMS ether was utilized to introduce the graft chain, while the main chain with the TMS and TBS ethers was introduced via the second PA function derived from the TBS ether. Thus, the same chain-end functionalities (both TMS and TBS ethers) were reintroduced after construction of the graft unit. In practice, the reaction sequence involving "the introduction of the graft chain" and "the introduction of the main chain with the two silyl ethers" was iterated three times, leading to the synthesis of poly(benzyl methacrylate) (PBnMA)-exact graft-poly(methyl methacrylate) (PMMA) with three PMMA graft chains. Similarly, the synthesis of PBnMA-exact graft-poly(2-vinylpyridine) (P2VP) with two P2VP graft chains was successfully carried out. With the use of the alpha,omega-chain-end-difunctionalized PBnMA as the starting material, two graft units could be constructed at the same time by iterating the reaction sequence once. The graft copolymers with up to six graft chains were obtained by only three repeated reaction sequences. Thus, the reaction steps could be significantly reduced. The graft copolymers synthesized in this study were perfectly controlled in structure from a viewpoint of the following three parameters defining the structure of the graft copolymer: (1) molecular weight of the main chain, (2) molecular weights of the graft chains, and (3) number and placement of the graft chains. Furthermore, these three parameters can also be intentionally changed as required.
Geometric phase and o-mode blueshift in a chiral anisotropic medium inside a Fabry-Perot cavity
(2015-11-24)
Timofeev, Ivan V.
;
Gunyakov, Vladimir A.
;
Sutormin, Vitaly S.
;
Myslivets, Sergey A.
;
Arkhipkin, Vasily G.
Anomalous spectral shift of transmission peaks is observed in a Fabry-Perot cavity filled with a chiral anisotropic medium. The effective refractive index value resides out of the interval between the ordinary and the extraordinary refractive indices. The spectral shift is explained by contribution of a geometric phase. The problem is solved analytically using the approximate Jones matrix method, numerically using the accurate Berreman method, and geometrically using the generalized Mauguin-Poincare rolling cone method. The o-mode blueshift is measured for a 4-methoxybenzylidene-4'-n-butylaniline twisted-nematic layer inside the Fabry-Perot cavity. The twist is electrically induced due to the homeoplanar-twisted configuration transition in an ionic-surfactant-doped liquid crystal layer. Experimental evidence confirms the validity of the theoretical model.
Competing Anisotropy-Tunneling Correlation of the CoFeB/MgO Perpendicular Magnetic Tunnel Junction: An Electronic Approach
(2015-11-24)
Yang, Chao-Yao
;
Chang, Shu-Jui
;
Lee, Min-Han
;
Shen, Kuei-Hung
;
Yang, Shan-Yi
We intensively investigate the physical principles regulating the tunneling magneto-resistance (TMR) and perpendicular magnetic anisotropy (PMA) of the CoFeB/MgO magnetic tunnel junction (MTJ) by means of angle-resolved x-ray magnetic spectroscopy. The angle-resolved capability was easily achieved, and it provided greater sensitivity to symmetry-related d-band occupation compared to traditional x-ray spectroscopy. This added degree of freedom successfully solved the unclear mechanism of this MTJ system renowned for controllable PMA and excellent TMR. As a surprising discovery, these two physical characteristics interact in a competing manner because of opposite band-filling preference in space-correlated symmetry of the 3d-orbital. An overlooked but harmful superparamagnetic phase resulting from magnetic inhomogeneity was also observed. This important finding reveals that simultaneously achieving fast switching and a high tunneling efficiency at an ultimate level is improbable for this MTJ system owing to its fundamental limit in physics. We suggest that the development of independent TMR and PMA mechanisms is critical towards a complementary relationship between the two physical characteristics, as well as the realization of superior performance, of this perpendicular MTJ. Furthermore, this study provides an easy approach to evaluate the futurity of any emerging spintronic candidates by electronically examining the relationship between their magnetic anisotropy and transport.
Quinone-Modified Mn-Doped ZnS Quantum Dots for Room-Temperature Phosphorescence Sensing of Human Cancer Cells That Overexpress NQO1
(2015-11-25)
Sung, Yi-Ming
;
Gayam, Srivardhan Reddy
;
Hsieh, Pei-Ying
;
Hsu, Hsin-Yun
;
Diau, Eric Wei-Guang
Early detection of cancer cells in a rapid and sensitive approach is one of the great challenges in modern clinical cancer care. This study has demonstrated the first example of a rapid, selective, and sensitive phosphorescence probe based on phosphorescence energy transfer (PET) for cancer-associated human NAD(P)H:quinone oxidoreductase isozyme 1 (NQO1). An efficient room-temperature phosphorescence NQO1 probe was constructed by using Mn-doped ZnS quantum dots (Mn:ZnS QDs) as donors and trimethylquinone propionic acids as acceptors. Phosphorescence quenching of Mn:ZnS QDs from the Mn:ZnS QDs to a covalently bonded quinone was achieved through PET. Phosphorescence of Mn:ZnS QDs was turned on by the rapid reduction-initiated removal of the quinone quencher by NQO1. This probe shows low cellular toxicity and can rapidly distinguish between NQO1-expressing and -nonexpressing cancer cell lines through phosphorescence imaging.
歌手之夢　蹣跚步履二十年
(2015-11-29)
吳和謙
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Department of Communication and Technology
;
傳播與科技學系
林建均，一位歌唱比賽常勝軍，也是個經驗豐富的歌唱教師與評審，卻從來不敢自稱是歌手。
我生命中遇到的貓
(2015-11-29)
蕭泳
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Department of Communication and Technology
;
傳播與科技學系
我所遇過的貓，是我生活重要的一部分，也是我重要的朋友，藉此表達我的思念與祝福。
以家為本　舞出文化
(2015-11-29)
曾煥富
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Department of Communication and Technology
;
傳播與科技學系
一個關於霹靂舞者Over The Top與跳舞文化的故事。
林青榖　峰迴路轉的人生
(2015-11-29)
黃美恩
;
Department of Communication and Technology
;
傳播與科技學系
家庭醫學科醫生林青榖勇敢向大眾詳述自己兩次罹患憂鬱的心路歷程，希望帶給大眾積極正面的能量。
金錢戰爭下的年輕難民
(2015-11-29)
唐宜嘉
;
Department of Communication and Technology
;
傳播與科技學系
平凡的大學生時枝修，一夕之間失去所有，反覆徘徊於社會底層的各個陰暗角落，最終成為露宿街頭的遊民。
揭開空軍基地的神秘面紗
(2015-11-29)
張家瑋
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Department of Communication and Technology
;
傳播與科技學系
兩年一度的新竹空軍基地開放日再度到來，讓民眾能親眼看看它的真面目。
性與不性　妙手回「春」
(2015-11-29)
薛如真
;
Department of Communication and Technology
;
傳播與科技學系
性治療師，一份鮮少被關注的職業。性愛帶來歡愉，當性發生問題，愛也隨之產生裂痕，性治療師協助處理生理與心理的性問題。
十鼓　擊出文創新力量
(2015-11-29)
王聖安
;
Department of Communication and Technology
;
傳播與科技學系
十鼓擊樂團改造舊糖廠，用鼓樂與文創保留台灣文化。
半調子運動員的傷兵日記
(2015-11-29)
趙廣絜
;
Department of Communication and Technology
;
傳播與科技學系
對於運動員而言，沒有什麼是比受傷還更痛苦的事了。
獨一無二　浴火琉璃
(2015-11-29)
鄭淇云
;
Department of Communication and Technology
;
傳播與科技學系
逐漸式微的傳統工業，在老師傅的手上重新發光發熱。
青郊草地音樂季　飄揚樂曲
(2015-11-29)
王鈞鋒
;
林湘芸
;
Department of Communication and Technology
;
傳播與科技學系
交通大學與清華大學兩校學聯會所舉辦的第一屆「青郊草地音樂季」，讓學生一同欣賞藝人與社團所帶來的表演。
星光熠熠　電競全明星賽
(2015-11-29)
林儒均
;
林筱晴
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Department of Communication and Technology
;
傳播與科技學系
知名遊戲《英雄聯盟》舉辦2015 LMS明星賽，邀請眾多電競好手以及明星藝人同台較勁，也吸引眾多粉絲前來觀賽。
誰換了一個頭貼？
(2015-11-29)
許凱智
;
Department of Communication and Technology
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傳播與科技學系
網路使用盛行，頭貼變成網路身分辨識的一個指標，也同時闡述許多關於使用者的事情。
桂圓·冰糖‧水
(2015-11-29)
竇玉帥
;
Department of Communication and Technology
;
傳播與科技學系
那瓶桂圓冰糖水中，映照著媽媽和朋友的模樣。
誰殺了白雪公主
(2015-11-29)
何佳頴
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Department of Communication and Technology
;
傳播與科技學系
湊佳苗黑暗作品《白雪公主殺人事件》，對網路霸凌、媒體亂象，以及同事之間心機的鬥爭描寫鞭辟入裡。
賣一捐一　助人利己
(2015-11-29)
徐義薇
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Department of Communication and Technology
;
傳播與科技學系
創業家布雷克打造社會企業的成功招牌，TOMS的故事可以做為創業領域的教材，卻不是一套填鴨式的模板。