Browsing by Issue Date, starting with "2014-07-14"

Now showing 1 - 20 of 25997

High contrast ratio and compact-sized prism for DLP projection system
(2014-07-14)
Huang, Yung-Chih
;
Pan, Jui-Wen
;
光電系統研究所
;
照明與能源光電研究所
;
生醫電子轉譯研究中心
In this paper, a novel light separator with contrast ratio enhancement but maintaining the optical efficiency of the DLP projection system is proposed. The main capability of the novel light separator is to direct the uncontrolled light away from the image system. The working theorem for the novel light separator is derived as well. Uncontrolled light is kept away from the image system by a total internal reflection surface, thereby effectively improving the image quality. Compared with the conventional contrast ratio enhancement method, the FO:FO contrast ratio can be improved from 839: 1 to 48250: 1, the ANSI contrast ratio can be improved from 180: 1 to 306: 1, while the image system efficiency remains at 76.2%. (C) 2014 Optical Society of America
Kane-Mele Hubbard model on a zigzag ribbon: Stability of the topological edge states and quantum phase transitions
(2014-07-14)
Chung, Chung-Hou
;
Lee, Der-Hau
;
Chao, Sung-Po
;
電子物理學系
;
Department of Electrophysics
We study the quantum phases and phase transitions of the Kane-Mele Hubbard (KMH) model on a zigzag ribbon of honeycomb lattice at a finite size via the weak-coupling renormalization group (RG) approach. In the noninteracting limit, the Kane-Mele (KM) model is known to support topological edge states where electrons show helical property with orientations of the spin and momentum being locked. The effective interedge hopping terms are generated due to finite-size effect. In the presence of an on-site Coulomb (Hubbard) interaction and the interedge hoppings, special focus is put on the stability of the topological edge states (TI phase) in the KMH model against (i) the charge and spin gaped (II) phase, (ii) the charge gaped but spin gapless (IC) phase, and (iii) the spin gaped but charge gapless (CI) phase depending on the number (even/odd) of the zigzag ribbons, doping level (electron filling factor) and the ratio of the Coulomb interaction to the interedge tunneling. We discuss different phase diagrams for even and odd numbers of zigzag ribbons. We find the TI-CI, II-IC, and II-CI quantum phase transitions are of the Kosterlitz-Thouless (KT) type. By computing various correlation functions, we further analyze the nature and leading instabilities of these phases. The relevance of our results for graphene is discussed.
Dose-dependent regulation of cell proliferation and collagen degradation by estradiol on ligamentum flavum
(2014-07-15)
Chen, Mei-Hsiu
;
Hu, Chao-Kai
;
Chen, Pei-Ru
;
Chen, Yu-Shan
;
Sun, Jui-Sheng
Background: Estradiol plays an important role in the regulation of collagen metabolism. Deficiency of estradiol has been reported to be associated with the degeneration of many connective tissues. However, the association of estradiol and hypertrophy of the ligamentum flavum was seldom explored. Therefore, we studied the effects of estradiol on cultured cells from the ligamentum flavum. Methods: Primary cultures of human ligamentum flavum cells obtained from surgical specimens of 14 patients undergoing spinal surgery were used to investigate the effect of estradiol on cell proliferation and the expression of collagen, elastin, and matrix metalloproteinases. Downstream pathways of estrogen receptor underlying the regulation of metalloproteinases were also investigated. Results: In our study, we revealed the existence of estrogen receptors on both female and male ligamentum flavum cells with a gender difference. 17 beta-estradiol increased early (24 hours) proliferation of ligamentum flavum cells in a dose dependent manner and the effect could not be seen when the cell density increased. Estradiol with a concentration of 10-9 M decreased collagen levels and increased the expression of MMP-13. Adding an antagonist of PI3K downstream pathway could reverse the expression of MMP-13 caused by estradiol. Conclusions: The results implied estradiol regulated the expression of MMP-13 via PI3K pathway and contributed to the homeostasis of extracellular matrix in the ligamentum flavum.
An ODE for boundary layer separation on a sphere and a hyperbolic space
(2014-07-15)
Chan, Chi Hin
;
Czubak, Magdalena
;
Yoneda, Tsuyoshi
;
應用數學系
;
Department of Applied Mathematics
Ma and Wang derived an equation linking the separation location and times for the boundary layer separation of incompressible fluid flows. The equation gave a necessary condition for the separation (bifurcation) point. The purpose of this paper is to generalize the equation to other geometries, and to phrase it as a simple ODE. Moreover we consider the Navier-Stokes equation with the Coriolis effect, which is related to the presence of trade winds on Earth. (C) 2014 Elsevier B.V. All rights reserved.
An ODE for boundary layer separation on a sphere and a hyperbolic space
(2014-07-15)
Chan, Chi Hin
;
Czubak, Magdalena
;
Yoneda, Tsuyoshi
;
應用數學系
;
Department of Applied Mathematics
Ma and Wang derived an equation linking the separation location and times for the boundary layer separation of incompressible fluid flows. The equation gave a necessary condition for the separation (bifurcation) point. The purpose of this paper is to generalize the equation to other geometries, and to phrase it as a simple ODE. Moreover we consider the Navier-Stokes equation with the Coriolis effect, which is related to the presence of trade winds on Earth. (C) 2014 Elsevier B.V. All rights reserved.
Resolution improvement in laser diode-based pump-probe microscopy with an annular pupil filter
(2014-07-15)
Miyazaki, Jun
;
Kawasumi, Koshi
;
Kobayashi, Takayoshi
;
電子物理學系
;
Department of Electrophysics
We experimentally demonstrate the use of annular beams to improve lateral resolution in laser-diode-based pump-probe microscopy. We found that the width of the point-spreading function in the case of the annular pump-probe beams is 162 nm, which is 30% smaller than that of the circular beams (232 nm). Furthermore, side lobes were efficiently suppressed at the focal plane since the pump-probe signal is proportional to the product of the two beam intensities. This scheme is demonstrated for the photothermal signal of nonfluorescent gold nanoparticles and the stimulated emission signal of fluorescence beads. (C) 2014 Optical Society of America
Numerical simulations of three-dimensional foam by the immersed boundary method
(2014-07-15)
Kim, Yongsam
;
Lai, Ming-Chih
;
Peskin, Charles S.
;
Seol, Yunchang
;
應用數學系
In this paper, we extend (Kim et al., 2010 [13]) to the three-dimensional dry foam case, i.e., a foam in which most of the volume is attributed to its gas phase. Dry foam dynamics involves the interaction between a gas and a collection of thin liquid-film internal boundaries that partitions the gas into discrete cells or bubbles. The liquid-film boundaries are flexible, contract under the influence of surface tension, and are permeable to the gas which moves across them by diffusion at a rate proportional to the local pressure difference across the boundary. Such problems are conventionally studied by assuming that the pressure is uniform within each bubble. Here, we introduce instead an immersed boundary method that takes into account the non-equilibrium fluid mechanics of the gas. To model gas diffusion across the internal liquid-film boundaries, we allow normal slip between the boundary and the gas at a velocity proportional to the (normal) force generated by the boundary surface tension. We implement this method in the three-dimensional framework, and test it by verifying the 3D generalization of the von Neumann relation, which governs the coarsening of a three-dimensional dry foam. (C) 2014 Elsevier Inc. All rights reserved.
Structural characterization of colloidal crystals and inverse opals using transmission X-ray microscopy
(2014-07-15)
Huang, Bo-Han
;
Wang, Chun-Chieh
;
Liao, Chen-Hong
;
Wu, Pu-Wei
;
Song, Yen-Fang
A nondestructive tomographic technique was used to determine the crystallographic information of colloidal crystals comprising of polystyrene (PS) microspheres, as well as their silver inverse opals. The properties of the colloidal crystals, such as defects, grain size, grain boundaries, stacking sequence, and grain orientation, were determined using the full field transmission X-ray microscopy (TXM) with a spatial resolution of 50 nm. The PS microspheres (500-750 nm) which underwent a vertical electrophoresis process to form a face-centered cubic (fcc) close-packed structure with an ABCABC packing sequence. In addition, the colloidal crystal exhibited multiple grains, and an orientation variation of 6.1 degrees in the stacking direction between two neighboring grains. (C) 2014 Elsevier Inc. All rights reserved.
Corona-wire unipolar aerosol charger
(2014-07-15)
Tsai Chuen-Jinn
;
Chien Chih-Liang
;
Wattanamekhinkul Virat
This invention relates to the reduction of charged particle loss by radially introducing sheath air from the porous wall. The corona-wire unipolar aerosol charger of the present invention includes a charging chamber, at least one aerosol inlet channel, a corona wire, an annular sheath air inlet opening, a porous tube defining a charging chamber, an annular sheath air outlet opening, and an aerosol outlet channel. The sheath air inlet opening is for radially introducing a sheath air flow into the charging chamber. The charged particles will not deposit on the wall surface of the charger if the radial velocity of the introduced sheath air at the wall is higher or comparable to the electrostatic velocity of charged particles. The dilution effect of charged particle due to the use of clean air can be further minimized by redirecting the excess clean air to the outside of the charger.
Sums of orthogonal projections
(2014-07-15)
Choi, Man-Duen
;
Wu, Pei Yuan
;
應用數學系
;
Department of Applied Mathematics
In this paper, we consider the problem of characterizing Hilbert space operators which are expressible as a sum of (finitely many) orthogonal projections. We obtain a special operator matrix representation and some necessary/sufficient conditions for an infinite-dimensional operator to be expressible as a sum of projections. We prove that a positive operator with essential norm strictly greater than one is always a sum of projections, and if an injective operator of the form I + K, where K is compact, is a sum of projections, then either trace K+ = trace K- = infinity on or K is of trace class with trace K a nonnegative integer. We also consider sums of those projections which have a fixed rank. The closure of the set of sums of projections is also characterized. (C) 2014 Elsevier Inc. All rights reserved.
Biological composite and method for reducing H2S
(2014-07-15)
Tseng Ching-Ping
;
Chen Yu-Pei
A biological composite and method for reducing H2S are disclosed. The biological composite for reducing H2S includes a carrier and Thermus sp. immobilized on the carrier. Therefore, if a sample containing H2S has contact with Thermus sp. or the carrier with Thermus sp. immobilized thereon, the amount of H2S can be reduced.
藥物篩選方法
(2014-07-16)
楊進木
;
許凱程
一種藥物篩選方法，包括：從化合物數據庫篩選出能與野生型標靶結合及能與突變型標靶之突變區結合的化合物，分析該野生型標靶及該突變型標靶之結合區的特徵並確認出候選藥物，以及進行生物分析。該藥物篩選方法有利於篩選同時對野生型標靶及突變型標靶有效果的藥物。
Photocatalytic Reduction of CO2 Using Ti-MCM-41 Photocatalysts in Monoethanolamine Solution for Methane Production
(2014-07-16)
Wu, Hung-Yu
;
Bai, Hsunling
;
Wu, Jeffrey C. S.
;
環境工程研究所
;
Institute of Environmental Engineering
Photocatalytic reduction of carbon dioxide (CO2) to form a valuable energy source of methane (CH4) in monoethanolamine (MEA) solution is first investigated by mesoporous photocatalysts of Ti-MCM-41 in this study. The MEA solution was chosen as the absorbent and reductant because amine absorption is one of the most popular methods for CO2 capture from flue gas streams. Also, it is intended to integrate the CO2 capture and utilization into one process. The photocatalytic results of methane yields indicated that MEA served as a better reductant than water and NaOH which have been commonly used for CO2 reduction. For the best photocatalyst of Ti-MCM-41(50) manufactured at a Si/Ti molar ratio of 50, its methane yield (62.42 mu mol/g of cat.) was much higher than that of commercial P25 photocatalyst after 8 h of UV illumination. A photoreduction quantum efficiency (PQE) of 9.18% was achieved.
金屬板材測試系統及其測試方法
(2014-07-16)
洪景華
;
陳彥佑
;
蔡宇中
本發明提供一種金屬板材測試系統，其至少包含夾持裝置、液壓裝置與量測裝置。夾持裝置具有第一模具、第二模具與超彈體墊片，其中第一模具與第二模具間可夾持一試片組中的任一者，且超彈體墊片係可拆地設置於試片組中之任一者與第二模具間。液壓裝置連接夾持裝置，並經由第二模具提供液壓於試片組中之任一者以使其朝向第一模具方向膨脹。量測裝置則分別連接夾持裝置與液壓裝置以即時量測液壓之瞬間壓力與試片組中之任一者的膨脹高度。前述金屬板材測試系統的測試方法亦揭露於本發明中。
一維鈦金屬奈米結構及其製造方法
(2014-07-16)
陳澤龍
;
裘性天
;
李紫原
一種一維鈦金屬奈米結構及其製造方法，使用化學氣相沉積方式，並利用反應溫度300~900℃，沉積溫度為200~850℃，載流氣體之流量0.1~50sccm，反應時間5~60小時，將鈦金屬與四氯化鈦反應完成後，即可於耐溫基材上生成一維鈦金屬奈米結構，一維金屬奈米結構可包含鈦奈米線、鈦奈米帶、花狀鈦奈米線、鈦奈米柱、鈦奈米管以及鈦金屬與二氧化鈦核殼結構之不同型態，且可以很緻密的成長於耐溫基材上，而本發明的製作不需要藉由複雜的微影蝕刻技術，不用額外合成模板，也沒有配製溶液及混漿塗膜等繁雜步驟，藉此可大幅降低製作成本及縮短製作流程，並具有可以放大製程的特點。
Photocatalytic Reduction of CO2 Using Ti-MCM-41 Photocatalysts in Monoethanolamine Solution for Methane Production
(2014-07-16)
Wu, Hung-Yu
;
Bai, Hsunling
;
Wu, Jeffrey C. S.
;
環境工程研究所
;
Institute of Environmental Engineering
Photocatalytic reduction of carbon dioxide (CO2) to form a valuable energy source of methane (CH4) in monoethanolamine (MEA) solution is first investigated by mesoporous photocatalysts of Ti-MCM-41 in this study. The MEA solution was chosen as the absorbent and reductant because amine absorption is one of the most popular methods for CO2 capture from flue gas streams. Also, it is intended to integrate the CO2 capture and utilization into one process. The photocatalytic results of methane yields indicated that MEA served as a better reductant than water and NaOH which have been commonly used for CO2 reduction. For the best photocatalyst of Ti-MCM-41(50) manufactured at a Si/Ti molar ratio of 50, its methane yield (62.42 mu mol/g of cat.) was much higher than that of commercial P25 photocatalyst after 8 h of UV illumination. A photoreduction quantum efficiency (PQE) of 9.18% was achieved.
具有共享位元線之１０個電晶體之二對埠靜態隨機存取記憶體
(2014-07-16)
黃威
;
王道平
本發明揭露一種具有共享位元線之10個電晶體之二對埠靜態隨機存取記憶體,其包含一第一及一第二記憶體單元。第一記憶體單元具有一第一儲存單元、一第一及一第二切換器組,第二記憶體單元具有一第二儲存單元、一第三及一第四切換器組。該第二切換器組連接至一A埠反相第一位元線、一B埠反相第一位元線、及該第一儲存單元。該第三切換器組連接至該A埠反相第一位元線、該B埠反相第一位元線、及該第二儲存單元。其中,該第二記憶體單元藉由該第三切換器組,以和該第一記憶體單元共用該A埠反相第一位元線及該B埠反相第一位元線。
多功能控制照明裝置
(2014-07-16)
莊仁輝
;
鄧文治
本發明係揭露一種多功能控制照明裝置,包含一同步分離器、一參數設定裝置、一視訊處理器與一發光裝置,同步分離器連接一攝影機與參數設定裝置,參數設定裝置再與發光裝置連接。同步分離器接收攝影機傳來之一視訊訊號,以擷取其中之同步訊號輸出至參數設定裝置,使其依據至少一種照明參數產生其對應之一電訊號,並將其傳送至發光裝置。最後,發光裝置則依據電訊號向攝影機之一攝影方向發射亮度呈週期性變化之一光線,以於攝影機端得到各種明暗程度不同的曝光影像,可避免遠處人物曝光不足,近處人物過曝情形並提升影像品質。
螢光奈米層殼結構及其製備方法和用途
(2014-07-16)
劉典謨
;
周輔宣
;
洪維陽
;
顏廷祐
一種螢光奈米層殼結構及其製備方法和用途，乃將兩性改質之幾丁聚醣高分子自組裝形成的奈米微胞，以層接層技術，使甲氧基苄腈螢光分子透過靜電作用力吸附並覆蓋於奈米微胞表面，以形成螢光奈米層殼結構，此螢光奈米層殼結構可以將甲氧基苄腈螢光分子良好地運送至細胞內，並藉由甲氧基苄腈螢光分子具有酸鹼敏感及螢光的特性，可用來量測細胞內酸鹼值而推測癌細胞之存在，並兼顧有細胞顯影之能力，可用於癌細胞之定位。
跌倒防護系統及方法
(2014-07-16)
楊秉祥
;
林承葦
一種跌倒防護系統及方法,首先在使用者身上配帶具有防護功能之防護裝置,接著,利用預先儲存有跌倒閾値之可攜式裝置偵測使用者日常生活中之動作,以取得行動狀態値,並且將該行動狀態値與跌倒閾値進行比對,以判別使用者之狀態是否為跌倒,並且在判定為跌倒開始時,由可攜式裝置發送觸發訊號予防護裝置,以啓動防護裝置之防護功能,避免使用者跌倒碰撞而造成傷害。