Browsing by Issue Date, starting with "2020-01-14"

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Observation of hydroperoxyethyl formate from the reaction between the methyl Criegee intermediate and formic acid
(2020-01-14)
Cabezas, Carlos
;
Endo, Yasuki
;
應用化學系
;
Department of Applied Chemistry
Rapid reactions of carboxylic acids with Criegee intermediates provide efficient gas phase removal processes and are proposed to trigger the formation of new molecular compounds, which are implicated in the growth of atmospheric aerosols. The new adducts formed in these reactions are known as hydroperoxide esters and are predicted to be condensable, with lower vapor pressures than the reactants. We report here the direct detection of hydroperoxyethyl formate (HOOCH(CH3)OCHO) formed in the gas phase reaction between the methyl substituted Criegee intermediate, CH3CHOO, and formic acid. Two different isomers of this hydroperoxide ester have been observed using the combination of pulsed Fourier-transform microwave spectroscopy with isotopic substitution experiments and high-level quantum chemical calculations. The identification of hydroperoxyethyl formate as the main nascent product of the CH3CHOO and HCOOH reaction differs from previous results that reported the formation of vinyl hydroperoxide as the reaction product of this reaction.
Amino-functionalization on graphene oxide sheets using an atomic layer amidation technique
(2020-01-14)
Gu, Siyong
;
Hsieh, Chien-Te
;
Mallick, Bikash Chandra
;
Gandomi, Yasser Ashraf
;
Chang, Jeng-Kuei
Nitrogen functionalization on graphene sheets has solely been demonstrated with a stepwise amidation implementation within the literature. The present work proposes an atomic layer amidation (ALN) technique to linearly adjust the surface amidation level on the carbon nanostructures. The ALN cycling protocol proposed in this work consists of an ammonia pulse, nitrogen pulse, and pumping at 100 and 150 degrees C. Both surface amidation and oxidation levels were linearly controlled by the ALN cycle number. The ALN technique was demonstrated as a self-limiting process capable of step-by-step N-functionalizing graphene oxide (GO) sheets on the atomic scale. The amidation reaction rates were ca. 0.023 (100 degrees C) and 0.028 atomic percent (at%) cycle(-1) (150 degrees C), and the apparent activation energy was determined to be 14.3 kJ mol(-1) (= 0.148 eV atom(-1)) from the Arrhenius equation. The amidation mechanism for forming the "chemical N" and "lattice N" at an atomic level was also proposed. Linearly controlling the optical band-gap with the ALN cycle number was suggested as a robust method for tuning the oxidation as well as the amidation level on the GO sheets. In this sense, nitrogen functionalization can be utilized for engineering any desirable properties within the graphene sheets.
In situ TEM investigation of electron beam-induced ultrafast chemical lithiation for charging
(2020-01-14)
Huang, Guan-Min
;
Huang, Chun-Wei
;
Kumar, Nagesh
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Huang, Chih-Yang
;
Tseng, Tseung-Yuen
The enhancement of operational life and charging speed have been considered to be two of the major factors that will influence the development of energy storage devices in the future. Here, we utilized an electron beam (e-beam) to retrieve Li metal from LiF, the degradation product of LiPF6, and trigger the further lithiation of NiFe2O4/carbon nanotubes (CNTs) to relieve the degradation of the electrolyte and achieve ultrafast lithiation. Accordingly, in situ transmission electron microscopy (in situ TEM) was used to investigate the comprehensive mechanism of the whole process. The e-beam acting on the degradation product, i.e., LiF clusters, led to the generation of Li flakes, which served as the source for the subsequent lithiation. Then, with these Li flakes, the chemical lithiation of the NiFe2O4/CNTs was triggered, resulting in phase transformation to Ni and Fe nanograins. Compared to "electrochemical" lithiation, ultrahigh reaction speed and the ability to charge without a directly applied potential in the "chemical" lithiation are expected to extend lithiation to more diverse applications. As a result of this investigation, we have provided a new strategy for designing novel energy storage devices for the energy-harvesting field.
金融科技與機器學習：財務文字資料分析
(國立交通大學丘成桐中心, 2020-01-15)
王釧茹
近年來，由於財務相關資料的大量累積，如何有效率地從中發現有用的訊息並用以進行更精準且有效的財務決策，遂成為一個重要的研究議題。這些訊息不僅可協助相關從業人員（如：會計師、分析師）掌握投資機會、最大程度地降低風險或控制成本，更可以運用至各種不同的金融場景。本文介紹文字分析（text mining）及自然語言處理（natural language processing）技術於非結構化財務文字資料上的相關技術及應用。
幾十年懸而未解計算機科學猜想的證明竟只需兩頁：再度窺見上帝的瑰寶
(國立交通大學丘成桐中心, 2020-01-15)
蔻拉萊克
;
林武雄
;
Erica Klarreich
一篇於今年七月線上 1 發表的論文解決一個懸宕將近 30 年有關電路基本組件結構的猜想。「靈敏度」（sensitivity）猜想多年來困惑了許多最傑出的資訊學家，然而新證明卻簡單到一個研究員用一條推文（tweet）就能總結。
中英名詞對照表
(國立交通大學丘成桐中心, 2020-01-15)
編輯室
中英名詞對照
數理簡訊
(國立交通大學丘成桐中心, 2020-01-15)
編輯室
當人工智慧遇見倫理
Anti-interference single-photon LiDAR using stochastic pulse position modulation
(2020-01-15)
Tsai, Chia-Ming
;
Liu, Yung-Chien
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This Letter introduces an anti-interference single-photon light detection and ranging (LiDAR) system with photon-driven stochastic pulse position modulation. A photon arrival sequence with a programmable minimum interval time and trigger rate was proposed to trigger laser pulses, thus providing true nature-based randomness in modulation which is beneficial for achieving bet ter anti-interference capability. In the proposed LiDAR system, two complementary metal-oxide-semiconductor single-photon avalanche diodes (SPADs) are used as an optical receiver and to generate a random trigger pattern of a pulsed laser. To prevent the range ambiguity problem, an interval-time filter capable of controlling the minimum interval time is integrated into the LiDAR system. A trigger rate controller capable of adaptively controlling the driving voltage of a light-emitting diode coupled with the SPAD responsible for the generation of the random trigger sequence is also integrated for achieving a precise control of trigger rate. Finally, a proof-ofconcept demonstration was provided through experiments, and the obtained results were consistent with theoretical predictions. At an effective trigger rate of 800 kHz,, an excellent suppression ratio of 56.2 dB has been achieved in the presence of a 1 MHz periodic interference. (C) 2020 Optical Society of America
數學家想要真正成功，必須被保護：2019 年阿貝爾獎得主烏蘭貝克訪談
(國立交通大學丘成桐中心, 2020-01-15)
烏蘭貝克
;
傑克森
;
翁秉仁
;
Karen Keskulla Uhlenbeck
;
Allyn Jackson
受訪者簡介烏蘭貝克 1942 年生，1966 年在布朗戴斯大學（Brandeis University）取得博士學位，指導教授是帕雷斯（Richard Palais）。先在麻省理工學院和加州大學柏克萊分校做博士後，再分別於伊利諾大學厄巴納 / 香檳分校（1971 ～1976）、伊利諾大學芝加哥分校（1976 ～ 1983）、芝加哥大學（1983 ～ 1988）擔任教職。1988 年起，她擔任德州大學奧斯丁分校的 Sid W. Richardson Foundation 講座教授。如今烏蘭貝克從德大退休，正在普林斯頓高等研究院訪問。過去半世紀，烏蘭貝克是分析學界的卓越領導人物之一，特別在幾何分析有深刻貢獻。令她最知名的可能是數學規範場論的研究，為 20 世紀數學最關鍵的進展之一奠定基礎。基於這項成就，於 2019 年她更獲頒數學界大獎阿貝爾獎。她還曾獲得麥克阿瑟獎（1983）等的多項榮譽與獎項。1990 年，她成為史上第二位在國際數學家大會（InternationalCongress of Mathematicians）做大會演講的女性，之前是 1932 年的諾特（Emmy Noether）。
電腦會有人文藝術的創作能力嗎？：人工智慧與人文藝術創作應用與研究
(國立交通大學丘成桐中心, 2020-01-15)
蘇豐文
人工智慧是一個探討如何利用機器來建構模擬人類智慧與能力的學問。所有人類的智慧行為都是人工智慧所探討的心理認知模型。過去人工智慧的研究從很多基礎的訣竅式搜索法、問題解法與規劃、自動邏輯推理模型、不確定模糊推理模型、知識表示法、情緒計算、常識推理、歸納學習演算法、最佳化演算法、類神經網路與深度學習等，有些甚至從生物與自然界的到靈感如：模擬退火演算法（simulate anneal arithmetic）、基因演算法（genetic algorithm）、群體智慧（swarm intelligence）等。歷史上很多的藝術天才（如莫札特音樂家、達文西美術家、蘇東坡文學家等）具有高人一等的天賦可以產生傳頌不朽的作品。這些能力人工智慧有一天可以達到嗎？
中國算學之過去與現在
(國立交通大學丘成桐中心, 2020-01-15)
陳省身
作者陳省身（Shiing Shen Chern，1911 年10 月28 日～ 2004 年12 月3 日），生於浙江嘉興秀水縣，美籍華裔數學大師，第一屆中央研究院院士，同時是法國科學院、義大利國家科學院、英國皇家學會和中國科學院的外籍院士。他是20 世紀最偉大的幾何學家之一，也是最有影響力的數學家之一。於1982 年在伯克萊大學退休後，建立了美國國家數學科學研究所（MSRI）。1984 年獲頒沃爾夫數學獎，是第一位得到沃爾夫獎的華裔科學獎。國際數學聯盟（IMU）為了紀念陳省身的卓越貢獻，在2014 年還特別設立了陳省身獎（Chern Medal）作為國際數學界最高級別的終身成就獎，這是第一個以華人為名的國際數學重要獎項。近十數年來中國算學的研究有了若干可喜的進步。為檢討過去，策勵將來起見，筆者願把中國算學家幾千年來所做的工作加以歷史的敘述，最後則略敘近年國人進行研究工作的大概情形，俾大家瞭然我們這個時代將在中國算學史上所佔的地位。
編輯曲線
(國立交通大學丘成桐中心, 2020-01-15)
編輯室
本期內容:電腦會有人文藝術的創作能力嗎？
中國的高等教育
(國立交通大學丘成桐中心, 2020-01-15)
丘成桐
作者丘成桐為哈佛大學數學與物理教授，費爾茲獎、克拉福得獎、沃爾夫獎、馬賽爾‧ 格羅斯曼獎得主，中央研究院院士。科普著作有《丘成桐談空間的內在形狀》，並為《數理人文》主編。本文為作者2019年6月11日於北京清華大學第八屆世界華人數學家大會（ICCM2019）公開演講稿。
An immersive head-mounted display with a liquid lens
(2020-01-15)
Wu, Tsung-Hsien
;
Pan, Jui-wen
;
光電系統研究所
;
影像與生醫光電研究所
;
Institute of Photonic System
An optical design for an immersive head-mounted display (HMD) with a liquid lens is described. This design combines the liquid lens with an immersive HMD system to improve the image quality for myopic and hyperopic users. A penta-prism is also incorporated and used to change the direction of the optical path to improve any optical aberration caused by the gravity effect. This immersive head-mounted display has a field of view of 14.9 degrees, focal length of 47.78 mm, and f-number of 5.97 with an exit pupil diameter of 8 mm, eye relief of 15 mm. The value of the MTF is above 0.9 at 3.3 lp/mm.
Composition-driven anionic disorder-order transformations triggered single-Eu2+ -converted high-color-rendering white-light phosphors
(2020-01-15)
Dai, Pengpeng
;
Wang, Qingling
;
Xiang, Mei
;
Chen, Teng-Ming
;
Zhang, Xintong
Single-component, single-activator-converted high-color-rendering index (CRI) white-light phosphors have sparked much interest for phosphor-converted white light-emitting diodes. However, manipulating the distribution and locations of single activators to target desired sites in a given host lattice is still a challenge. Herein, we report the remote regulation of the distribution of Eu2+ ions by engineering and controlling the structural ordering in Sr-3(Ce1-xLax)(PO4)(3):0.05Eu(2+) (SCLP:Eu2+) compound, which are designed by using two-color phosphors with different anionic structural ordering, viz., Sr3Ce(PO4)(3):Eu2+ (yellow) with disordered state of PO4 tetrahedra, and Sr3La(PO4)(3):Eu2+ (blue) with ordered state of PO4 tetrahedra. The successive substitution of Ce by La triggers a pronounced disorder-to-order structural transformation of PO4 tetrahedra within SCLP:Eu2+ compounds and guides remotely the distribution of Eu2+ activators, which is demonstrated by a detailed analysis of synchrotron X-ray diffraction refinement, electron paramagnetic resonance spectra, electron spin-echo envelope modulation spectra, Raman spectra, nuclear magnetic resonance spectra and micro-cathodoluminescence spectrum. Benefitting from the controllable structural ordering transformation, as-prepared samples form a unique disorder-order crystal structure, exhibiting controllable microstructure acting on Eu2+ ions, tunable-color emissions including a high CRI (Ra = 90) white-light, increased structural rigidity and thermal stability. These interesting findings in the local structure-dependent luminescence properties demonstrate that structural ordering engineering may be an effective approach to regulate the migration of Eu2+ activators and improve the thermal stability of phosphors.
理有所依、情有所达、心有所归：浅谈数学诗文
(国立交通大学丘成桐中心, 2020-01-15)
李雪甄
数学诗文是一种融合数学与文学的叙事方式，本文将从史诗、古诗、诗歌到文学，呈现不同数学诗文的样貌。并透过这些作品来了解，如何交融数学的真与诗文的美，才可以让文学的浪漫被数学接受，数学的奥妙被文学拥抱，连结后的诗文心意被看到，成为能圆满数学之“真”、文字之“美”、叙事之“善”的动人文章。
預測、學習、與賽局：線上學習簡介
(國立交通大學丘成桐中心, 2020-01-15)
李彥寰
線上學習（online learning）是當代機器學習理論的主流研究方向之一。最近幾年，在機器學習最具代表性的純理論會議 COLT（Conference on Learning Theory），總能看到許多的線上學習論文，有興趣的讀者可以在 YouTube 上找到這個會議的官方演講錄影。線上學習在實作上也非常重要。線上學習演算法的每一次迭代只需要讀取一筆資料，因此特別適用於資料量大到難以一次全部讀取的情境 —— 這就是當代大部分機器學習問題的典型情境。
Visible-Transparent Luminescent Solar Concentrators Based on Carbon Nanodots in the Siloxane Matrix with Ultrahigh Quantum Yields and Optical Transparency at High-Loading Contents
(2020-01-16)
Talite, Maria Jessabel
;
Huang, Hsiu-Ying
;
Cai, Kun-Bin
;
Co, King Chester Capinig
;
Santoso, Phoa Adelina Cynthia
Visible-transparent luminescent solar concentrators (VT-LSCs) can be integrated with solar cells for designing solar glasses. Recently, rare-earth complexes, semiconductor nanocrystals, and carbon nanodots (CNDs) have been applied in developing VT-LSCs. However, several challenges still existed, such as quantum yields (QYs) at high-loading contents, scattering/reabsorption losses, and stability. Here, highly luminescent and visible-transparent composites based on organosilane-functionalized CNDs (Si-CNDs) cross-linked in the siloxane matrix were prepared. The composites with a high-loading content (similar to 10 wt %) possess ultrahigh QYs of similar to 94% due to surface passivation, cross-linking-enhanced emission, and negligible inter-CND energy transfer. Moreover, they still appear exceptionally transparent and, thus, are suitable for VT-LSCs. Eco-friendly VT-LSCs without colored tinting were fabricated, yielding high internal and external quantum efficiencies of similar to 66% and similar to 3.9%. Our demonstration would pave a bright way for the utilization of eco-friendly VT-LSCs in solar glasses.
【輻射防護教育訓練】
(國立陽明大學, 2020-01-17)
陽明電子報編輯小組
【高雄市國立陽明大學校友會】～策略行銷思維講座暨理監事聯席會議
(國立陽明大學, 2020-01-17)
陽明電子報編輯小組