Browsing by Issue Date, starting with "2019-09-06"

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Benzophenanthrothiophenes: Syntheses, Crystal Structures, and Properties
(2019-09-06)
Venkateswarlu, Samala
;
Prakoso, Suhendro Purbo
;
Kumar, Sushil
;
Kuo, Ming-Yu
;
Tao, Yu-Tai
A new class of polycyclic heteroarenes based on benzo[3,4]phenanthro[1,2-b]benzo[3,4]phenanthro[2,1-d]thiophene (BPBPT) was prepared from polyaryl thiophenes via regioselective Scholl reactions. The molecular frameworks of these compounds exhibited twisted bridges and near-cofacial packing motifs with oppositely or parallel pi-stacked structures depending on the substituents on the periphery. Theoretical calculation of electronic coupling and charge mobility was carried out on the basis of the single-crystal structures. Single crystals of selected benzophenanthrothiophenes were used in p-channel field-effect transistor device fabrication, from which the highest mobility was measured as 2.03 cm(2) V-1 s(-1) from Flu-BPBPT.
Novel Role for miR-1290 in Host Species Specificity of Influenza A Virus
(2019-09-06)
Huang, Sheng-Yu
;
Huang, Chih-Heng
;
Chen, Chi-Jene
;
Chen, Ting-Wen
;
Lin, Chun-Yuan
The role of microRNA (miRNA) in influenza A virus (IAV) host species specificity is not well understood as yet. Here, we show that a host miRNA, miR-1290, is induced through the extracellular signal-regulated kinase (ERK) pathway upon IAV infection and is associated with increased viral titers in human cells and ferret animal models. miR-1290 was observed to target and reduce expression of the host vimentin gene. Vimentin binds with the PB2 subunit of influenza A virus ribonucleoprotein (vRNP), and knockdown of vimentin expression significantly increased vRNP nuclear retention and viral polymerase activity. Interestingly, miR-1290 was not detected in either chicken cells or mouse animal models, and the 3' UTR of the chicken vimentin gene contains no binding site for miR-1290. These findings point to a host species-specific mechanism by which IAV upregulates miR-1290 to disrupt vimentin expression and retain vRNP in the nucleus, thereby enhancing viral polymerase activity and viral replication.
The Criegee intermediate-formic acid reaction explored by rotational spectroscopy
(2019-09-07)
Cabezas, Carlos
;
Endo, Yasuki
;
應用化學系
;
Department of Applied Chemistry
The atmospheric reaction of the simplest Criegee intermediate, CH2OO, with formic acid has been investigated in the gas phase by pulsed Fourier-transform microwave spectroscopy. The dominant nascent product from this reaction was identified as hydroperoxymethyl formate (HOOCH2OCHO), for which two different conformations, formed through independent insertion mechanisms, were observed in the discharged plasma of a CH2I2/O-2/formic acid gas mixture. The conformational identifications are supported by the observation of C-13 species in natural abundance together with the chemically mono substituted deuterium isotopologues. These isotopic observations further suggest that hydroperoxymethyl formate slightly decomposes, producing formic anhydride (OHCOCHO) in a dehydration reaction.
Improved measurement of the reactor antineutrino flux at Daya Bay
(2019-09-09)
Adey, D.
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An, F. P.
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Balantekin, A. B.
;
Band, H. R.
;
Bishai, M.
This work reports a precise measurement of the reactor antineutrino flux using 2.2 million inverse beta decay (IBD) events collected with the Daya Bay near detectors in 1230 days. The dominant uncertainty on the neutron detection efficiency is reduced by 56% with respect to the previous measurement through a comprehensive neutron calibration and detailed data and simulation analysis. The new average IBD yield is determined to be (5.91 +/- 0.09) x 10(-43) cm(2)/fission with total uncertainty improved by 29%. The corresponding mean fission fractions from the four main fission isotopes U-235, U-238, Pu-239, and( 241)Pu are 0.564, 0.076, 0.304, and 0.056, respectively. The ratio of measured to predicted antineutrino yield is found to be 0.952 +/- 0.014 +/- 0.023 (1.001 +/- 0.015 +/- 0.027) for the Huber-Mueller (ILL-Vogel) model, where the first and second uncertainty are experimental and theoretical model uncertainty, respectively. This measurement confirms the discrepancy between the world average of reactor antineutrino flux and the Huber-Mueller model.
Online news recommendations based on topic modeling and online interest adjustment
(2019-09-09)
Liu, Duen-Ren
;
Liao, Yu-Shan
;
Lu, Jun-Yi
;
交大名義發表
;
National Chiao Tung University
Purpose Providing online news recommendations to users has become an important trend for online media platforms, enabling them to attract more users. The purpose of this paper is to propose an online news recommendation system for recommending news articles to users when browsing news on online media platforms. Design/methodology/approach A Collaborative Semantic Topic Modeling (CSTM) method and an ensemble model (EM) are proposed to predict user preferences based on the combination of matrix factorization with articles' semantic latent topics derived from word embedding and latent topic modeling. The proposed EM further integrates an online interest adjustment (OIA) mechanism to adjust users' online recommendation lists based on their current news browsing. Findings This study evaluated the proposed approach using offline experiments, as well as an online evaluation on an existing online media platform. The evaluation shows that the proposed method can improve the recommendation quality and achieve better performance than other recommendation methods can. The online evaluation also shows that integrating the proposed method with OIA can improve the click-through rate for online news recommendation. Originality/value The novel CSTM and EM combined with OIA are proposed for news recommendation. The proposed novel recommendation system can improve the click-through rate of online news recommendations, thus increasing online media platforms' commercial value.
High throughput fabrication of large-area colloidal crystals via a two-stage electrophoretic deposition method
(2019-09-10)
Hung, Pei-Sung
;
Liao, Chen-Hong
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Chou, Yu-Szu
;
Wang, Guang-Ren
;
Wang, Chuan-Jyun
An effective and high-throughput method is demonstrated to produce a colloidal crystal with impressive crystallinity. The fabrication procedure involves a two-stage electrophoresis process in which a vertical electrophoretic deposition of polystyrene microspheres (495 nm) is conducted on an ITO substrate to form a colloidal crystal in size of 4 x 4 cm(2), followed by a horizontal electrophoresis to improve the packing crystallinity. Relevant parameters associated with the horizontal electrophoresis step including voltage polarity, bipolar voltage offset, and operation frequency are investigated. Their effects over the crystallinity of the colloidal crystals are verified quantitatively and qualitatively by structural observation via scanning electron microscope and optical reflectance spectra. We determine that the imposition of an alternately-changing bias of 80/0/-120/0 V at 10 Hz (25 ms in each bias) enables the production of colloidal crystals with the largest grain size (106 mm) and the smallest grain boundary (170 nm), as compared to samples prepared from a single vertical electrophoresis step. We attribute the improved crystallinity of the colloidal crystal to the bipolar bias that engenders localized movements of the microspheres, rendering them to pack more closely with reduced defects. (C) 2019 Elsevier Ltd. All rights reserved.
Design of an ultra-compact lowpass filter with ultra-sharp roll-off for UHF application
(2019-09-10)
Hsieh, Cheng-Hung
;
Tsai, Zuo-Min
;
電機工程學系
;
Department of Electrical and Computer Engineering
This letter proposes a UHF lowpass filter based on the image parameter method. This study designed, fabricated and assembled a 0.48-GHz semilumped lowpass filter using low cost FR4 substrate. It adopted a new layout concept for the air wound coils to achieve the purposes of compact size and good performances. The proposed UHF lowpass filter has the best performances for the roll-off rate and circuit size compared to previous works, and it also achieves the best figure of merit 973,369.
Demonstration of polarization control GaN-based micro-cavity lasers using a rigid high-contrast grating reflector
(2019-09-10)
Chang, Tsu-Chi
;
Kuo-Bin Hong
;
Kuo, Shuo-Yi
;
Lu, Tien-Chang
;
光電工程學系
We reported on GaN microcavity (MC) lasers combined with one rigid TiO2 high-contrast grating (HCG) structure as the output mirror. The HCG structure was directly fabricated on the GaN structure without an airgap. The entire MC structure comprised a bottom dielectric distributed Bragg reflector; a GaN cavity; and a top HCG reflector, which was designed to yield high reflectance for transverse magnetic (TM)- or transverse electric (TE)-polarized light. The MC device revealed an operation threshold of approximately 0.79 MW/cm(2) when pulsed optical pumping was conducted using the HCG structure at room temperature. The laser emission was TM polarized with a degree of polarization of 99.2% and had a small divergence angle of 14 degrees (full width at half maximum). This laser operation demonstration for the GaN-based MC structure employing an HCG exhibited the advantages of HCGs in semiconductor lasers at wavelengths from green to ultraviolet.
Culture-Related and Individual Differences in Regional Brain Volumes: A Cross-Cultural Voxel-Based Morphometry Study
(2019-09-10)
Huang, Chih-Mao
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Doole, Robert
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Wu, Changwei W.
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Huang, Hsu-Wen
;
Chao, Yi-Ping
Converging behavioral and functional neuroimaging evidence indicates that East Asian and Western individuals have different orientations for processing information that may stem from contrasting cultural values. In this cross-cultural magnetic resonance imaging (MRI) study, we used voxel-based morphometry (VBM) approach to investigate culture-related and individual differences of independent-interdependent orientation in structural brain volume between 57 Taiwanese and 56 Western participants. Each participant's degree of endorsement of independent and interdependent cultural value was assessed by their self-report on the Singelis Self-Construal Scale (SCS). Behaviorally, Taiwanese rated higher SCS scores than Westerners in interdependent value and Westerners rated higher SCS scores than Taiwanese in independent value. The VBM results demonstrated that Western participants showed greater gray matter (GM) volume in the fronto-parietal network, whereas Taiwanese participants showed greater regional volume in temporal and occipital regions. Our findings provide supportive evidence that socio-cultural experiences of learned independent-interdependent orientations may play a role in regional brain volumes. However, strategic differences in cognition, genetic variation, and/or modulations of other environmental factors should also be considered to interpret such culture-related effects and potential individual differences.
Isomerically Pure Benzothiophene-Incorporated Acceptor: Achieving Improved V-oc and J(sc) of Nonfullerene Organic Solar Cells via End Group Manipulation
(2019-09-11)
Chang, Shao-Ling
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Hung, Kai-En
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Cao, Fong-Yi
;
Huang, Kuo-Hsiu
;
Hsu, Chain-Shu
Benzene-based 1,1-dicyanomethylene-3-indanone (IC) derivatives have been widely utilized as the end-group to construct acceptor-donor-acceptor type nonfullerene acceptors (A-D-A type NFAs). The extension of the end-group conjugation of nonfullerene acceptors (NFAs) is a rational strategy to facilitate intermolecular stacking of the end-groups which are responsible for efficient electron transportation. A bicyclic benzothiophene-based end-group acceptor, 2-(3-oxo-2,3-dihydro-1H-benzo[b]cyclopenta[d]thiophen-1-ylidene)malononitrile, denoted as alpha-BC was designed and synthesized. The Knoevenagel condensation of the unsymmetrical 1,3-diketo-precursor with one equivalent of malononitrile selectively reacts with the keto group attached at the alpha-position of the thiophene unit, leading to the isomerically pure benzothiophene-fused alpha-BC. The well-defined alpha-BC with extended conjugation was condensed with three different ladder-type diformylated donors to form three new A-D-A NFAs named BDCPDT-BC, DTCC-BC, and ITBC, respectively. The corresponding IC-based BDCPDT-IC, DTCC-IC, and ITIC model compounds were also synthesized for comparison. The incorporation of the electron-rich benzothiophene unit in the end-group upshifts the lowest unoccupied molecular orbital energy levels of the NFAs, which beneficially enlarges the V-oc values. On the other hand, the benzothiophene unit in alpha-BC not also imparts an optical transition in the shorter wavelengths around 340-400 nm for a better light harvesting ability but also promotes the antiparallel pi-pi stacking of the end-groups for efficient electron transport. The organic photovoltaic cell devices using a PBDB-T polymer and BC-based NFAs all showed the improved V-oc and J(sc) values. The BDCPDT-BC- and DTCC-BC-based devices exhibited a power conversion efficiency (PCE) of 10.82 and 10.74%, respectively, which outperformed the corresponding BDCPDT-IC-, and DTCC-IC-based devices (9.33 and 9.25%). More importantly, the ITBC-based device delivered the highest PCE of 12.07% with a J(sc) of 19.90 mA/cm(2), a V-oc of 0.94 V, and an fill factor of 64.51%, representing a 14% improvement relative to the traditional ITIC-based device (10.05%).
【108學年上學期學餐營業時間】
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組
陽明與信馨公司簽約，推動科技照護產學合作
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組
陽明與國內首家以科技企業模式投入長照服務的信馨公司，9月3日簽署產學合作備忘錄，將由信馨引進與技轉陽明相關醫療與照護科技專...
新生入學典禮，郭校長以「三印主義」勉勵新生
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組
陽明9月5日舉行新生入學典禮，郭旭崧校長在致詞的時候，以「三印主義」 Independent（獨立）、Intellectual（知識）、Internation...
陽明與交大完成合校計畫書，九月送校務會議表決
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組
「國立陽明大學暨國立交通大學合校工作委員會」已於8月完成合校計畫書，預計於9月送交兩校校務會議表決，通過後即可送交教育部審...
生技醫療講座：新創公司如何作有效果的媒體行銷？
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組
由陽明創新育成中心舉辦的「生技醫療創新創業講座」，8月28日特邀請《環球生技月刊》林明定社長暨總編輯，以「大風吹、吹什麼？...
【職場軟實力系列講座】職場成功的人際溝通術
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組
Manipulation of Heteroatom Substitution on Nitrogen and Phosphorus Co-Doped Graphene as a High Active Catalyst for Hydrogen Evolution Reaction
(2019-09-12)
Hung, Yu-Han
;
Dutta, Dipak
;
Tseng, Chung-Jen
;
Chang, Jeng-Kuei
;
Bhattacharyya, Aninda J.
Graphene doped with heteroatoms is known to create a unique electronic structure with comparatively much higher active sites by the synergistic coupling effect. However, in the earlier attempts, the atomic structure of such co-doped graphene could not be altered; thus, there is a lack of reports discussing the influence of the atomic arrangement in the catalytic performance of the co-doped graphene. Here, by co-doping P and N atoms in graphene as a model system, we present a facile and two-step process wherein the sequence of doping helps in manipulating the heteroatom substitution, which is of great importance in defining better crystallinity and conductivity and favorable elemental functionalities and hence improving catalytic performance. The present method provides a clean, flexible, binder-free, and readily available electrocatalyst that avoids tedious conventional synthesis and device fabrication steps. The highest P-doping percentage (6 at. %) in the present work is superior to previous reports (3 at. %). By altering the sequence of N- and P-doping, the co-doped graphene electrode displayed excellent performance, with an increment of 148% in the sp(2) domain size and enormous lowering in overpotential and Tafel slope (78%). Further, the efficiency of the hydrogen evolution reaction catalyst sustains >98% for 20 h, which is significantly higher than the well-known MoSx (63%). Although here the P-N co-doped system was utilized as a proof of concept, this method could be adapted for other versatile co-doped graphene. This work may pave the way for the development of co-doped graphene-based devices where manipulation of atomic arrangement can result in a structure with properties desirable for catalytic or electronics applications.
【服務學習說明會】Enrich your life
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組
【基因體編輯服務平台教育訓練】
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組
【實驗動物福祉和動物權】
(國立陽明大學, 2019-09-12)
陽明電子報編輯小組