Browsing by Issue Date, starting with "2018-04-09"

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Carbodicarbenes and their Captodative Behavior in Catalysis
(2018-04-09)
Liu, Shu-kai
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Shih, Wei-Chih
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Chen, Wen-Ching
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Ong, Tiow-Gan
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交大名義發表
That of carbones is a new family member in the class of low-valent carbon compounds. Unlike its cousin, the conventional carbene, the carbone possesses two free electron lone pairs. In combination with their unique allene-type structure, they possess stronger sigma-donating ability than conventional carbenes such as NHCs or CAACs. Because of this property, they have a huge potential to become a new class of ligands in organometallic chemistry and catalysis. Although carbodiphosphoranes (CDP) were initially discovered in 1961, nearly 50years were needed to attract the attention of the chemical community with the synthesis of the carbodicarbene (CDC). This Concept paper summarizes developments over the last 10years and future outlooks for this new class of sigma-donors, particularly carbodicarbenes.
Atomic Heterointerfaces and Electrical Transportation Properties in Self-Assembled LaNiO3-NiO Heteroepitaxy
(2018-04-09)
Zhu, Yuan Min
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Thi Hien Do
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Vu Thanh Tra
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Yu, Rong
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Chu, Ying-Hao
Vertical nanostructure heteroepitaxy opens new opportunities for designing next-generation electronic devices due to the enthralling multifunction combinations and the abundant heterointerfaces manipulated effects. In this study, self-assembled heteroepitaxial thin films, vertically aligned metallic LaNiO3 (LNO) and semiconducting NiO with diverse heterointerfaces, are created and systematically investigated by advanced transmission electron microscopy. With the increase of LaNiO3 content, the LaNiO3 phases present as isolated islands encircled by the connected NiO nanoplates and eventually become the continuous matrix with embedded NiO nanopillars. The atomic heterointerface between NiO and LaNiO3 phases is determined to be [NiO2-LaO](LaNiO3)-LaO-[NiO](NiO), in which an extra La-O layer is enriched at the heterointerface. Besides, the formation mechanism of the heterointerface and antiphase boundaries observed in LaNiO3 phase is discussed. The electrical transport properties at room temperature can be tuned gradually by changing the volume ratio of constituents. The correlation among the insulator-to-metal transition, the carrier types associated with transport behaviors, and the heterostructure evolutions are explored. This study offers a desirable platform to design new multifunctional electronic devices based on the oxide heterojunctions.
交大e-News第252期-交領甲子育英才通聯世界燦未來
(2018-04-09)
國立交通大學秘書室
;
Secretariat
Negative circular polarization emissions from WSe2/MoSe2 commensurate heterobilayers
(2018-04-10)
Hsu, Wei-Ting
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Lu, Li-Syuan
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Wu, Po-Hsun
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Lee, Ming-Hao
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Chen, Peng-Jen
Van der Waals heterobilayers of transition metal dichalcogenides with spin-valley coupling of carriers in different layers have emerged as a new platform for exploring spin/valleytronic applications. The interlayer coupling was predicted to exhibit subtle changes with the interlayer atomic registry. Manually stacked heterobilayers, however, are incommensurate with the inevitable interlayer twist and/or lattice mismatch, where the properties associated with atomic registry are difficult to access by optical means. Here, we unveil the distinct polarization properties of valley-specific interlayer excitons using epitaxially grown, commensurate WSe2/MoSe2 heterobilayers with well-defined (AA and AB) atomic registry. We observe circularly polarized photoluminescence from interlayer excitons, but with a helicity opposite to the optical excitation. The negative circular polarization arises from the quantum interference imposed by interlayer atomic registry, giving rise to distinct polarization selection rules for interlayer excitons. Using selective excitation schemes, we demonstrate the optical addressability for interlayer excitons with different valley configurations and polarization helicities.
Metal Sulfate Poisoning Effects over MnFe/TiO2 for Selective Catalytic Reduction of NO by NH3 at Low Temperature
(2018-04-11)
Lee, Tsungyu
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Bai, Hsunling
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環境工程研究所
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Institute of Environmental Engineering
The MnFe/TiO2 catalysts were poisoned by metal sulfates and/or ammonium sulfate to understand the SO2 poisoning effect under low-temperature selective catalytic reduction (SCR) of NO with NH3. The results showed that the formation of metal sulfates had a more serious deactivation effect than that of ammonium salts on the MnFe/TiO2 catalysts. After thermal regeneration, the metal sulfates on the catalyst could not be removed so that the NOx conversion was only recovered from 17% to 35%. On the other hand, water washing was capable to remove both ammonium salts and metal sulfates, and the NOx conversion could be recovered to 88% (compared to 99% for the fresh catalyst). The analytical results of the synchrotron-based XRD, BET, NH3-TPD, and XPS revealed that lower crystallinity, lower specific surface area, lower ratio of Mn4+/Mn3+, higher surface acidity, and more chemisorbed oxygen were the main causes for the presence of metal sulfates poisoning, which then resulted in the low NOx conversion at low temperature.
Nanochip-Induced Epithelial-to-Mesenchymal Transition: Impact of Physical Microenvironment on Cancer Metastasis
(2018-04-11)
Dhawan, Udesh
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Sue, Ming-Wen
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Lan, Kuan-Chun
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Buddhakosai, Waradee
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Pao Hui Huang
Epithelial-to-mesenchymal transition (EMT) is a highly orchestrated process motivated by the nature of physical and chemical compositions of the tumor microenvironment (TME). The role of the physical framework of the TME in guiding cells toward EMT is poorly understood. To investigate this, breast cancer MDA-MB-231 and MCF-7 cells were cultured on nanochips comprising tantalum oxide nanodots ranging in diameter from 10 to 200 nm, fabricated through electrochemical approach and collectively referred to as artificial microenvironments. The 100 and 200 nm nanochips induced the cells to adopt an elongated or spindle-shaped morphology. The key EMT genes, E-cadherin, N-cadherin, and vimentin, displayed the spatial control exhibited by the artificial microenvironments. The E-cadherin gene expression was attenuated, whereas those of N-cadherin and vimentin were amplified by 100 and 200 rim nanochips, indicating the induction of EMT. Transcription factors, snail and twist, were identified for modulating the EMT genes in the cells on these artificial microenvironments. Localization of EMT proteins observed through immunostaining indicated the loss of cell cell junctions on 100 and 200 rim nanochips, confirming the EMT induction. Thus, by utilizing an in vitro approach, we demonstrate how the physical framework of the TME may possibly trigger or assist in inducing EMT in vivo. Applications in the fields of drug discovery, biomedical engineering, and cancer research are expected.
A new failure mechanism of electromigration by surface diffusion of Sn on Ni and Cu metallization in microbumps
(2018-04-12)
Chang, Yuan-Wei
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Hu, Chia-chia
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Peng, Hsin-Ying
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Liang, Yu-Chun
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Chen, Chih
Microbumps in three-dimensional integrated circuit now becomes essential technology to reach higher packaging density. However, the small volume of microbumps dramatically changes the characteristics from the flip-chip (FC) solder joints. For a 20 mu m diameter microbump, the cross-section area and the volume are only 1/25 and 1/125 of a 100 mu m diameter FC joint. The small area significantly enlarges the current density although the current crowding effect was reduced at the same time. The small volume of solder can be fully transformed into the intermetallic compounds (IMCs) very easily, and the IMCs are usually stronger under electromigration (EM). These result in the thoroughly change of the EM failure mechanism in microbumps. In this study, microbumps with two different diameter and flip-chip joints were EM tested. A new failure mechanism was found obviously in microbumps, which is the surface diffusion of Sn. Under EM testing, Sn atoms tend to migrate along the surface to the circumference of Ni and Cu metallization to form Ni3Sn4 and Cu3Sn IMCs respectively. When the Sn diffuses away, necking or serious void formation occurs in the solder, which weakens the electrical and mechanical properties of the microbumps. Theoretic calculation indicates that this failure mode will become even significantly for the microbumps with smaller dimensions than the 18 mu m microbumps.
Magnetic properties of type-I and type-II Weyl semimetals in the superconducting state
(2018-04-12)
Rosenstein, Baruch
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Shapiro, B. Ya.
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Li, Dingping
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Shapiro, I.
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電子物理學系
Superconductivity was observed in certain range of pressure and chemical composition in Weyl semimetals of both type I and type II (when the Dirac cone tilt parameter kappa > 1). Magnetic properties of these superconductors are studied on the basis of microscopic phonon-mediated pairing model. The Ginzburg-Landau effective theory for the order parameter is derived using the Gorkov approach and used to determine anisotropic coherence length, the penetration depth determining the Abrikosov parameter for a layered material and applied to recent extensive experiments on MoTe2. It is found that superconductivity is of second kind near the topological transition at kappa = 1. For a larger tilt parameter, superconductivity becomes first kind. For kappa < 1, the Abrikosov parameter also tends to be reduced, often crossing over to the first kind kappa For the superconductors of the second kind, the dependence of critical fields H-c2 and H-c1 on the tilt parameter. (governed by pressure) is compared with the experiments. Strength of thermal fluctuations is estimated and it is found that they are strong enough to cause Abrikosov vortex lattice melting near H-c2. The melting line is calculated and is consistent with experiments provided the fluctuations are three dimensional in the type-I phase (large pressure) and two dimensional in the type-II phase (small pressure).
METHOD FOR ADVANCING NON-MAGNETICALLY RESPONSIVE FUNCTIONAL AGENT
(2018-04-12)
Ching-Yao CHEN
;
Yan-Hom LI
;
Ren-Chiuan SHIU
A method for advancing a non-magnetically responsive functional agent includes steps (a) and (b). In step (a), a magnetically responsive agent construct at a target site is subjected to a homogeneous static magnetic field such that magnetically responsive micro particles are aligned to obtain a magnetic chain while the non-magnetically responsive functional agent is separated and discrete from the magnetic chain. In step (b), the magnetic chain is subjected to a rotational magnetic field to cause repeating breaking up and reformation of the magnetic chain such that the non-magnetically responsive functional agent is displaced to a predetermined position.
Selective extraction of n-butylidenephthalide from Angelica sinensis (Danggui) by using functionalized iron oxide magnetic nanoparticles as trapping probes
(2018-04-14)
Wu, Ching-Yi
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Wu, Min-Li
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Chen, Yu-Chie
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應用化學系
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Department of Applied Chemistry
n-Butylidenephthalide (BP) is an active compound in Angelica sinensis (Danggui) and a potential anti-cancer drug. Thus, purification of BP from complex herb extract samples is important. In this study, we develop a facile method for selective purification of BP from complex samples by using iron oxide magnetic nanoparticles (Fe3O4 MNPs) immobilized with riboflavin-50-phosphate (RFMP) as affinity probes. RFMP is a polyaromatic compound that contains a phosphate, which can readily chelate with the metal center on the surface of Fe3O4 MNPs. The aromatic rings on RFMP can interact with BP (K-d = similar to 6.73 x 10(-5) M) through pi-pi stacking. Thus, Fe3O4@RFMP MNPs are fabricated by simply mixing Fe3O4 MNPs with RFMP under microwave heating (power: 540 W) for 3 min. The as-prepared Fe3O4@RFMP MNPs can be used as affinity probes to selectively concentrate BP from an acidic solution; BP is then released from the MNPs by using acetonitrile. The recovery of BP from the Fe3O4@RFMP MNP-BP conjugates is estimated to be similar to 100%. This study also demonstrates the feasibility of using the proposed approach to selectively extract BP from complex A. sinensis extract samples.
二手玩具世界──玩聚窩
(2018-04-15)
楊巧柔
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Department of Communication and Technology
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傳播與科技學系
【二手玩具物流】專題

玩聚窩放置的玩具全數為二手玩具，經過整理及分類，開放一般民眾使用，讓親子在假日多一個好去處。
找尋文化和環保的平衡　邵璦婷
(2018-04-15)
吳佩芸
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Department of Communication and Technology
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傳播與科技學系
【天燈施放　傳統文化與環保的角力】專題

邵璦婷與團隊成員一同研發環保天燈，在文化、環保與經濟之間找到一條新出路。
新興的傳播力量：資訊圖表正夯
(2018-04-15)
郭庭芸
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Department of Communication and Technology
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傳播與科技學系
【不只是美　看見設計的力量】專題

I have an info, I have a graphic, uh! Infographic! 近年來，台灣對於資訊圖表設計的關注度逐漸升高，本篇將以資訊圖表的格式介紹資訊圖表相關的小知識。
持續發展的潛力股　生酮飲食
(2018-04-15)
楊佩臻
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Department of Communication and Technology
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傳播與科技學系
【飲食與健康】專題

生酮飲食是什麼？其中又有什麼利與弊？讓我們一起來了解吧！
Comparison of ZnO and Ti-doped ZnO sensing membrane applied in electrolyte-insulator-semiconductor structure
(2018-04-15)
Lee, Ming Ling
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Wang, Jer Chyi
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Kao, Chyuan Haur
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Chen, Hsiang
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Lin, Chan Yu
In this paper, we demonstrate electrolyte-insulator-semiconductor devices for biochemical sensing applications prepared from ZnO and Ti-doped ZnO sensing membranes deposited on Si substrates by radio frequency sputtering. The structural, morphological, and compositional features of these deposited films with multitemperature annealing were studied using X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy, respectively. Sensitivity, linearity, hysteresis, and drift rate were measured to determine the sensing and reliability performance of all fabricated devices. Compared to the ZnO electrolyte-insulator-semiconductor (EIS), the Ti-doped ZnO EIS sensor annealed at 700 degrees C exhibits a higher sensitivity of 57.56 mV/pH, lower hysteresis of 2.79 mV, and lower drift rate of 0.29 mV/h. For Ti-doped ZnO, sensitivities of 3.62 mV/mM and 6.42 mV/mM were obtained for urea and glucose sensing, respectively. The improvements are owing to Ti-doping, which produces a rougher sensing surface, a well-crystallized grain structure, and thinner silicate and SiO2 at the silicon-oxide interface.
A-Team　負數開始累積人氣
(2018-04-15)
巫尹文
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Department of Communication and Technology
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傳播與科技學系
【台灣偶像團體的困境與未來】專題

經歷抄襲風波的台灣新男團A-Team，將批評化為前進動力，努力充實實力，並於今年二月發行了首張EP「44釐米」。
箏開新視野　視障藝術家周進發
(2018-04-15)
簡嘉瑩
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Department of Communication and Technology
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傳播與科技學系
【他們的故事　身心障礙者】專題

聾盲藝術家周進發，在黑暗世界中，用古箏譜出屬於他的美麗色彩。
注音符號發展史
(2018-04-15)
謝宛蓁
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Department of Communication and Technology
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傳播與科技學系
【注音符號：中文巴別塔】專題

在ㄅㄆㄇ爭議中，支持注音符號的網友以《施氏食獅史》一文嘲諷使用羅馬拼音的後果，此舉反映了對注音符號和拼音的嚴重誤解。此篇將帶您了解注音符號與漢語拼音的誕生歷史，一同探悉其背後的軌跡。
認識僑生　那些他們常被問的事
(2018-04-15)
關子茵
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Department of Communication and Technology
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傳播與科技學系
【僑生面面觀】專題

大家對僑生總是有很多好奇和疑問，就用這張圖表為你們解惑吧。
總編輯的話
(2018-04-15)
王貞懿
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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285期，稿件共計19篇。本期頭題為《募不募？動畫募資比一比》，以圖表方式呈現出台灣動畫的募資特性。