Browsing by Issue Date, starting with "2019-02-04"

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Fluorescent Fe Embedded Magnetic Nanodiamonds Made by Ion Implantation
(2019-02-04)
Lin, Bo-Rong
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Kunuku, Srinivasu
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Chen, Chien-Hsu
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Chen, Tzung-Yuang
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Hsiao, Tung-Yuan
We demonstrate fluorescent Fe embedded magnetic nanodiamonds by ion implantation and two-step annealing. The diamond characteristics with a highly ordered core and a graphite surface layer are maintained after the implantation process. After the two-step annealing process, a bright red fluorescence associated with nitrogen-vacancy centers is observed. These new fluorescent magnetic nanodiamonds can be used as a dual-function in vivo tracer with both optical visibility and magnetic resonance imaging capabilities. They are potentially useful for the more advanced in vivo biological and medical applications.
High-Rate Hydrogen Generation by Direct Sunlight Irradiation with a Triruthenium Complex
(2019-02-04)
Wu, Tung-Kung
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Chen, Yi-Ting
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Peng, Chun-Sheng
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Lin, Jia-Hoa
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Gliniak, Jacek
Herein we report a biomimetic triruthenium catalyst that, when under direct sunlight irradiation, facilitates high-rate H-2 production from formic acid (FA) dehydrogenation. The system consists of 2 mu mol of catalyst and 6 mu mol of tri-o-tolylphosphine in 1 mL of dimethylformamide (DMF) and 4 mL of FA/triethylamine (TEA; 5:2). With 0.4 mM catalyst loaded, a high turnover frequency of 1.15 X 10(6) h(-1) was detected when under direct sunlight irradiation. In an experiment with 0.2 mM catalyst loaded, more than 140 L of H-2 (280 L of H-2 + CO2) was produced, and a turnover number of approximately 2.78 X 10(6) was obtained within 5 h without decline in H-2 generation activity, making it suitable for high-rate H-2 production.
Color breakup suppression based on global dimming for field sequential color displays using edge information in images
(2019-02-04)
Lin, Fang-Cheng
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Qin, Zong
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Teng, Kai-Tung
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Huang, Yi-Pai
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光電工程學系
Considering the high complexity of local dimming backlight that is necessary to effectively suppress color breakups for field sequential color liquid crystal displays (FSC-LCDs), a global dimming-based solution is proposed. This solution involves considering that the color breakups mainly occur at object edges of an image. By introducing an algorithm to present the edge information in a single field, evaluating color breakup performances, and experimentally verifying based on a 240-Hz LCD, lighter color breakups are revealed compared with mainstream local dimming-based solutions. Therefore, the proposed solution can achieve FSC-LCDs with better performance and practicality for advanced display applications. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Applying big data analytics to support Kansei engineering for hotel service development
(2019-02-04)
Chen, Mu-Chen
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Hsiao, Yu-Hsiang
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Chang, Kuo-Chien
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Lin, Ming-Ke
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運輸與物流管理系註：原交通所+運管所
Purpose Leisure and tourism activities have proliferated and become important parts of modern life, and the hotel industry plays a necessary role in the supply for and demand from consumers. The purpose of this paper is to develop guidelines for hotel service development by applying a service development approach integrating Kansei engineering and text mining. Design/methodology/approach The online reviews represent the voice of customers regarding the products and services. Consumers' online comments might become a key factor for consumers choosing hotels when planning their tourism itinerary. With the framework of Kansei engineering, this paper adopts text mining to extract the sets of Kansei words and hotel service characteristics from the online contents as well as the relationships among Kansei words, service characteristics and these two sets. The relationships are generated by using link analysis, and then the guidelines for hotel service development are proposed based on the obtained relationships. Findings The results of the present research can provide the hotel industry a comprehensive understanding of hotels' customers opinions, and can offer specific advice on how to differentiate one's products and services from competitors' in order to improve customer satisfaction and increase hotels' performance in the end. Finally, this study finds out the service development guidelines to meet customers' requirements which can provide suggestions for hotel managers. The implications both for academic and industry are also drawn based on the obtained results. Originality/value Now, in the internet era, consumers can comment on their hotel living experience directly through the internet. The large amount of user-generated content (UGC) provided by consumers also provides chances for the hospitality industry to understand consumers' opinions through online review mining. The UGC with consumers' opinions to hotel services can be continuously collected and analyzed by hoteliers. Therefore, this paper demonstrates how to apply the hybrid approach integrating Kansei engineering and online review mining to hotel service development.
Efficient high-power continuous-wave lasers at green-lime-yellow wavelengths by using a Nd:YVO4 self-Raman crystal
(2019-02-04)
Chen, Y. F.
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Pan, Y. Y.
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Liu, Y. C.
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Cheng, H. P.
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Tsou, C. H.
Efficient high-power continuous-wave Nd:YVO4 visible lasers at versatile wavelengths of 532 (green). 559 (lime). and 588 nm (yellow) are demonstrated to be achieved by using the identical cavity mirrors and gain medium. A dichroic coating is deposited on one end surface of the gain medium to gather the backward green-yellow emission. The green. lime. and yellow outputs are individually optimized by using different phase-matched lithium triborate (LBO) crystals for second harmonic generation (SHG) of the fundamental field, sum frequency generation (SFG) of the fundamental and the stimulated Raman fields. and SHG of the stimulated Raman field, respectively. At a pump power of 31.6 W, the output powers at 532, 559, and 588 nm can be up to 6.8. 5.4. and 3.1 W. The high efficient and compact Nd:YVO4 lasers at green-lime-yellow wavelengths can be potentially beneficial to future applications in retinal photocoagulation. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Carbonylation of Alkyl Radicals Derived from Organosilicates through Visible-Light Photoredox Catalysis
(2019-02-04)
Cartier, Alex
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Levernier, Etienne
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Corce, Vincent
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Fukuyama, Takahide
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Dhimane, Anne-Lise
Primary, secondary, and tertiary alkyl radicals formed by the photocatalyzed oxidation of organosilicates underwent efficient carbonylation with carbon monoxide (CO) to give a variety of unsymmetrical ketones. This study introduces the possibility of radical carbonylation under a photooxidative regime.
Design of a bi-directional illumination system for a dual view capsule endoscope
(2019-02-06)
Sheu, Ming-Jen
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Liu, Ying-Lan
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Wang, Jhi-Joung
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Pan, Jui-Wen
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光電系統研究所
The capsule endoscope is an important tool for the intestinal examination. But the main disadvantage of the traditional capsule endoscope is the limited field of view. In order to solve this problem, the dual view capsule endoscope (DVCE) was developed. In this work, a dual view illumination system is designed for a DVCE. The dual view illumination system is divided into two sub-systems with a front view illumination lens and a back view illumination lens. The Bezier curves for the front view and back view illumination lenses are used for optimization, based on which we change the radiation pattern of the LED so that the dual view illumination design can support energy for the front view and back view simultaneously while achieving low power consumption and high efficiency. Moreover, a non-uniform illumination process is used to compensate for the problem of uniformity and relative illumination for the DVCE lens. Through this design, we can obtain a uniformity of 91% and an efficiency of 25.2% for front view illumination and uniformity of 91% and an efficiency of 23.5% for back view illumination. Finally, tolerance analysis can also be completed for mass production.
Specific drug delivery efficiently induced human breast tumor regression using a lipoplex by non-covalent association with anti-tumor antibodies
(2019-02-06)
Lin, Yu-Ling
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Tsai, Nu-Man
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Chen, Chia-Hung
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Liu, Yen-Ku
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Lee, Chung-Jen
BackgroundA cationic liposome-PEG-PEI complex (LPPC) was employed as a carrier for achieving targeted delivery of drug to human epidermal growth factor receptor-2 (HER2/neu)-expressing breast cancer cells. LPPC can be easily loaded with an anti-tumor drug and non-covalently associated with an anti-tumor antibody such as Herceptin that is clinically used to rapidly form immunoparticles within 1h.ResultsDrug-loaded LPPC have an average size about 250nm and a zeta potential of about 40mV. Herceptin was complexed onto surface of the LPPC to form the drug/LPPC/Herceptin complexes. The size of curcumin/LPPC/Herceptin complexes were 280nm and the zeta potentials were about 23mV. Targeting ability of this delivery system was demonstrated through specific binding on surface of cells and IVIS images in vivo, which showed specific binding in HER2-positive SKBR3 cells as compared to HER2-negative Hs578T cells. Only the drug/LPPC/Herceptin complexes displayed dramatically increased the cytotoxic activity in cancer cells. Both in vitro and in vivo results indicated that Herceptin adsorbed on LPPC directed the immunocomplex towards HER2/neu-positive cells but not HER2/neu-negative cells. The complexes with either component (curcumin or doxorubicin) used in the LPPC-delivery system provided a better therapeutic efficacy compared to the drug treatment alone and other treatment groups, including clinical dosages of Herceptin and LipoDox, in a xenografted model.ConclusionsLPPC displays important clinical implications by easily introducing a specific targeting characteristic to drugs utilized for breast cancer therapy.
IN VIVO AMELIORATION OF ENDOGENOUS ANTI-TUMOR AUTOANTIBODIES TARGETING SURFACE TUMOR ANTIGENS VIA LOW-DOSE P4N
(2019-02-06)
HUANG, Ru Chih C.
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MOLD, David
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JACKSON, Tiffany
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LIN, Yu-Ling
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LIAO, Kuang-Wen
Structure and Strain Relaxation of GaN Nanorods Grown on Homoepitaxial Surface via Controlling Irregular Mask
(2019-02-07)
Huang, Chang-Hsun
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Pakzad, Anahita
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Lee, Wei-I
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Chou, Yi-Chia
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電子物理學系
We propose a simple and low-cost approach using irregular mask for growing GaN nanorods (NRs) bottom up on a freestanding GaN substrate through hydride vapor-phase epitaxy. The irregular mask consists of uncoalesced SiO2 islands deposited by plasma-enhanced chemical vapor deposition to isolate growth. The selection of the SiO2 amount is investigated to achieve reasonable NR density (high coverage), desired morphology (flat side walls and uniform diameters), and lattice quality (single crystalline; better quality than that of an as-grown layer under the same growth ambient). Using this growth approach with appropriate parameters, we successfully synthesize high coverage of uncoalesced NRs on a homoepitaxial surface in a short growth duration. The morphology, density, and growth rate are controlled by adjusting V/III ratios. The cathodoluminescence and photoluminescence measurements of GaN show that luminescence was obtained near 3.4 eV while the structure was grown with mask but contained defect signals when grown without mask. The residual strain relaxation within the GaN NRs has been confirmed using Raman spectrum and scanning transmission electron microscopy strain mapping. Moreover, we demonstrate the strain distribution between different crystalline qualities and lattice orientations in GaN NR The method provides a quick and inexpensive method for future nanofabrication consideration.
Image-text dual neural network with decision strategy for small-sample image classification
(2019-02-07)
Zhu, Fangyi
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Ma, Zhanyu
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Li, Xiaoxu
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Chen, Guang
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Chien, Jen-Tzung
Small-sample classification is a challenging problem in computer vision. In this work, we show how to efficiently and effectively utilize semantic information of the annotations to improve the performance of small-sample classification. First, we propose an image-text dual neural network to improve the classification performance on small-sample datasets. The proposed model consists of two sub-models, an image classification model and a text classification model. After training the sub-models separately, we design a novel method to fuse the two sub-models rather than simply combine their results. Our image-text dual neural network aims to utilize the text information to overcome the training problem of deep models on small-sample datasets. Then, we propose to incorporate a decision strategy into the image-text dual neural network to further improve the performance of our original model on few-shot datasets. To demonstrate the effectiveness of the proposed models, we conduct experiments on the LabelMe and UIUC-Sports datasets. Experimental results show that our method is superior to other models. (C) 2018 Elsevier B.V. All rights reserved.
Effects of electrostatic environment on the electrically triggered production of entangled photon pairs from droplet epitaxial quantum dots
(2019-02-07)
Ramirez, Hanz Y.
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Chou, Ying-Lin
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Cheng, Shun-Jen
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電子物理學系
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Department of Electrophysics
Entangled photon pair generation is a crucial task for development of quantum information based technologies, and production of entangled pairs by biexciton cascade decays in semiconductor quantum dots is so far one of the most advanced techniques to achieve it. However, its scalability toward massive implementation requires further understanding and better tuning mechanisms to suppress the fine structure splitting between polarized exciton states, which persists as a major obstacle for entanglement generation from most quantum dot samples. In this work, the influence of electrostatic environment arising from electrically biased electrodes and/or charged impurities on the fine structure splitting of GaAs/AlGaAs droplet epitaxial quantum dots is studied, by means of numerical simulations considering a realistic quantum dot confining potential and electron-hole exchange interaction within a multiband k.p framework. We find that reduction of the fine structure splitting can be substantially optimized by tilting the field and seeding impurities along the droplet elongation axis. Furthermore, our results provide evidence of how the presence of charged impurities and in-plane bias components, may account for different degrees of splitting manipulation in dots with similar shape, size and growth conditions.
On possibility of determining neutrino mass hierarchy by the charged-current and neutral-current events of supernova neutrinos in scintillation detectors
(2019-02-12)
Lee, Fei-Fan
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Lee, Feng-Shiuh
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Lai, Kwang-Chang
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電機學院
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College of Electrical and Computer Engineering
One of the unresolved mysteries in neutrino physics is the neutrino mass hierarchy. We present a new method to determine neutrino mass hierarchy by comparing the events of inverse beta decays (IBD), e+pn+e+, and neutral current (NC) interactions, ()+p()+p, of supernova neutrinos from accretion and cooling phases in scintillation detectors. Supernova neutrino flavor conversions depend on the neutrino mass hierarchy. On account of Mikheyev-Smirnov-Wolfenstein effects, the full swap of the e flux with the x (,) one occurs in the inverted hierarchy, while such a swap does not occur in the normal hierarchy. In consequence, the ratio of high energy IBD events to NC events for the inverted hierarchy is higher than in the normal hierarchy. Since the luminosity ofe is larger than that of x in accretion phase while the luminosity of e becomes smaller than that of x in cooling phase, we calculate this ratio for both accretion and cooling phases. By analyzing the change of this event ratio from accretion phase to cooling phase, one can determine the neutrino mass hierarchy.
LIGHT EMISSION DIODE WITH FLIP-CHIP STRUCTURE AND MANUFACTURING METHOD THEREOF
(2019-02-14)
RAY-HUA HORNG
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RAY-HUA HORNG
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HUAN-YU CHIEN
A light emitting diode device with flip-chip structure includes a transparent protective substrate, a transparent conductor layer, a glue layer, a group III-V stack layer, a first conductivity metal electrode, a second conductivity metal electrode and an insulating layer. The transparent conductor layer is formed on the transparent protective substrate. The glue layer bonds the transparent protective substrate and the transparent conductor layer. The group III-V stack layer and the first conductivity metal electrode are respectively formed on a first portion and a second portion of the transparent conductor layer. The second conductivity metal electrode is formed on a portion of the group III-V stack layer. The insulating layer covers exposed portions of the transparent conductor layer and the group III-V stack layer, and the insulating layer further covers portions of the first and second conductivity metal electrodes, so as to expose the first and second conductivity metal electrodes.
Efficient Electrostatic Particle-into-liquid Sampler Which Prevents Sampling Artifacts
(2019-02-14)
Chuen-Jinn Tsai
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Chao-Ting Hsu
The present invention discloses an efficient electrostatic particle-into-liquid sampler (EPILS). The EPILS collects an aerosol sample in the dry mode and extracts it in the wet mode to prevent sampling artifacts. In the dry mode, a first stage utilizes carbon brushes as discharge electrodes to charge aerosol particles which are then collected on the cylinder wall by the electric field setup between the high-voltage central metal rod and the grounded cylinder in the second stage. In the wet mode, DI water is injected into the EPILS in a pulsation manner by opening and closing solenoid valves intermittently, which dislodges aerosol particles deposited on the cylinder wall effectively to become a liquid aerosol sample. The liquid aerosol sample is then analyzed for chemical compositions manually or automatically.
Enhanced wavelength-selective photoresponsivity with a MoS2 bilayer grown conformally on a patterned sapphire substrate
(2019-02-14)
Chen, Sung-Wen Huang
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Wang, Sheng-Wen
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Hong, Kuo-Bin
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Medin, Henry
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Chung, Chieh-Han
In the present study, novel MoS2 bilayers with 3D structures were considered for their application as wavelength-sensitive photodetectors. Using e-gun deposition and a CVD process, MoS2 bilayers can be grown conformally on a patterned (cones or pyramids) sapphire substrate without any wrinkles on the 2D film. After the sulfurization process, the MoS2 bilayer is subjected to a local strain in the patterns and its band gap gets enlarged due to the strain. This phenomenon is beneficial for photo-devices to enable the collection of the photocurrent. Measurements revealed a broadband enhancement of the MoS2-based photodetector with a patterned array in terms of both absorption and photocurrent. It is noteworthy that a cone-patterned sapphire substrate (CPSS) is able to generate more photocurrent when illuminated under blue light illumination, whereas the pyramid-patterned sapphire substrate (PPSS) performs best under green and red light illumination. Simulations of the electric field distributions for MoS2 coatings on different substrates, based on 3D models, revealed that the sensitivity of the MoS2-based photodetector can be greatly enhanced by the light-scattering effect.
Second Harmonic Light Manipulation with Vertical Split Ring Resonators
(2019-02-15)
Tsai, Wei-Yi
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Chung, Tsung Lin
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Hsiao, Hui-Hsin
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Chen, Jia-Wern
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Lin, Ren Jie
The second harmonic generation (SHG) of vertical and planar split-ring resonators (SRRs) that are broken centro-symmetry configurations at the interface of metal surface and air is investigated. Strong interactions, better electromagnetic field confinements, and less leakage into the substrate for vertical SRRs are found. Experimental results show a 2.6-fold enhancement of SHG nonlinearity, which is in good agreement with simulations and calculations. Demonstrations of 3D metastructures and vertical SRRs with strong SHG nonlinearity majorly result from magnetic dipole and electric quadrupole clearly provides potential applications for photonics and sensing.
Synthesis, Isolation, and Characterization of Mono- and Bis-norbornene-Annulated Biarylamines through Pseudo-Catellani Intermediates
(2019-02-15)
Annamalai, Pratheepkumar
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Hsiao, Huan-Chang
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Raju, Selvam
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Fu, Yi-Hsuan
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Chen, Pei-Ling
A palladium-catalyzed C-H functionalization of an external ring of N-acyl 2-aminobiaryl with bicyclo[2.2.1]-hept-2-ene (norbornene) via multiple C-H bond activations was developed. This study is the first report of the formation of bis-norbornene annulated biarylamines isomers (syn-3a'/anti-3a' = 36:64) from multiple C-H bond functionalizations. Additionally, nondirected C-H bond functionalization at the C-4' position with alkenes rendered complete C-H functionalization of five C-H bonds that formed a stable hexasubstituted benzene ring.
Microwave-assisted synthesis of SnO2/mesoporous carbon core-satellite microspheres as anode material for high-rate lithium ion batteries
(2019-02-15)
Chang, Pei-Yi
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Doong, Ruey-an
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環境工程研究所
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Institute of Environmental Engineering
The highly ordered microspheres containing ultrafine SnO2 nanoparticles and mesoporous carbon is fabricated using microwave-assisted hydrothermal method for high-rate and durable Li-ion battery application. The uniformly carbon nanosphere with an average diameter of around 90 nm exhibits large specific surface area and good mechanical stability to minimize the volume expansion of SnO2 during intercalation-deintercalation. The homogeneous coverage with 3-6 nm SnO2 nanoparticle provides sufficient active sites to facilitate the rapid lithiation-delithiation process through the fast ion transfer rates. Remarkably, SnO2/OMCS at Sn/C ratio of 35% exhibits an excellent initial capacity of 1770 mAh g(-1) at a current density of 35 mAg(-1) and can maintain at a stable capacity of 400 mAh g(-1) under an ultrahigh current density of 3500 mA g(-1) after 400 cycles. The intimate contact of SnO2 with ordered mesoporous carbon sphere shortens the electrons transport paths, resulting in the enhancement of stable lithium storage capacity at a high current density. Results obtained in this study clearly demonstrate that SnO2/OMCS nanocomposite is a promising material for lithium-ion battery and can provide an alternative to fabricate novel mesoporous carbon sphere-based nanocomposites for long cycle life and high-rate energy storage application. (C) 2018 Elsevier B.V. All rights reserved.
Electromagnetic field behavior of 3D Maxwell's equations for chiral media
(2019-02-15)
Huang, Tsung-Ming
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Li, Tiexiang
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Chern, Ruey-Lin
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Lin, Wen-Wei
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應用數學系
This article focuses on numerically studying the eigenstructure behavior of generalized eigenvalue problems (GEPs) arising in three dimensional (3D) source-free Maxwell's equations with magnetoelectric coupling effects which model 3D reciprocal chiral media. It is challenging to solve such a large-scale GEP efficiently. We combine the null-space free method with the inexact shift-invert residual Arnoldi method and MINRES linear solver to solve the GEP with a matrix dimension as large as 5,308,416. The eigenstructure is heavily determined by the chirality parameter gamma. We show that all the eigenvalues are real and finite for a small chirality gamma. For a critical value gamma = gamma*, the GEP has 2 x 2 Jordan blocks at infinity eigenvalues. Numerical results demonstrate that when gamma increases from gamma*, the 2 x 2 Jordan block will first split into a complex conjugate eigenpair, then rapidly collide with the real axis and bifurcate into positive (resonance) and negative eigenvalues with modulus smaller than the other existing positive eigenvalues. The resonance band also exhibits an anticrossing interaction. Moreover, the electric and magnetic fields of the resonance modes are localized inside the structure, with only a slight amount of field leaking into the background (dielectric) material. (C) 2018 Elsevier Inc. All rights reserved.