B→η(η′)K(π)B \to \eta(\eta') K(\pi) in the Standard Model with Flavor Symmetry

The observed branching ratios for $B\to K \eta'$ decays are much larger than factorization predictions in the Standard Model (SM). Many proposals have been made to reconcile the data and theoretical predictions. In this paper we study these decays within the SM using flavor U(3) symmetry. If small annihilation amplitudes are neglected, one needs 11 hadronic parameters to describe $B\to PP$ decays where $P$ can be one of the $\pi$, $K$, $\eta$ and $\eta'$ nonet mesons. We find that existing data are consistent with SM with flavor U(3) symmetry. We also predict several measurable branching ratios and CP asymmetries for $B \to K (\pi) \eta(\eta')$, $\eta(\eta')\eta(\eta')$ decays. Near future experiments can provide important tests for the Standard Model with flavor U(3) symmetry.Comment: 13 pages, 4 table

Atomistic nucleation sites of Pt nanoparticles on N-doped carbon nanotubes

[[abstract]]The atomistic nucleation sites of Pt nanoparticles (Pt NPs) on N-doped carbon nanotubes (N-CNTs) were investigated using C and N K-edge and Pt L3-edge X-ray absorption near-edge structure (XANES)/extended X-ray absorption fine structure (EXAFS) spectroscopy. Transmission electron microscopy and XANES/EXAFS results revealed that the self-organized Pt NPs on N-CNTs are uniformly distributed because of the relatively high binding energies of the adsorbed Pt atoms at the imperfect sites. During the atomistic nucleation process of Pt NPs on N-CNTs, stable Pt–C and Pt–N bonds are presumably formed, and charge transfer occurs at the surface/interface of the N-CNTs. The findings in this study were consistent with density functional theory calculations performed using cluster models for the undoped, substitutional-N-doped and pyridine-like-N-doped CNTs.[[journaltype]]國外[[incitationindex]]SCI[[booktype]]紙本[[countrycodes]]GB

CP Violation in B → PP Decays in the Standard Model with SU(3) Symmetry

In this paper we study CP violation in the B ! PP decays in the Standard Model using SU(3) avor symmetry. With SU(3) symmetry, only seven hadronic parameters are needed to describe the B ! PP decays in the SM, when annihilation contributions are neglected. The relevant hadronic parameters can be determined using known experimental data from B ! and B ! K. We predict branching ratios and CP asymmetries for some of the unmeasured B ! PP decays. Some of the CP asymmetries can be large and measured at B factories. The eects of the annihilation contributions can also be studied using the present experimental data. Inclusion of annihilation contributions introduces six more hadronic parameters. We nd that the annihilation contributions are in general small, but can have signicant eects on CP asymmetries and some Bs ! PP decays

Effects of Periodic Arrays and Surface Plasmons on Optical Properties of Semiconductors

在本論文中，我們研究了數種介電物質和金屬的光學特性，包括了以矽為材料的全能隙二維光子晶體，用金屬光柵製造CdSe/ZnS量子點的光學異向性，結合穿孔的金屬薄膜和一維光子晶體製作可選擇的熱輻射發射器，還有製作擁有大角度電致螢光光譜的ZnO奈米瓶子發光二極體。.擁有最大全能隙六角形連接的光子晶體們設計並且製作測量了一個擁有大全能隙的二維光子晶體，這個光子晶體的設計是根據一種多格子點加速反轉迭代法計算出來的。我們使用電子束微影和誘導式電漿離子反應蝕刻在矽上面製造光子晶體，並且發現由柱子和欄組合成的六角形陣列擁有最佳的光子全能隙。除此以外，我們還比較了之前常常研究的光子晶體設計，證明了我們設計的光子晶體有比較好的導光效果，因此我們的設計可以應用在高功率的光電元件上面。.利用金屬光柵的表面電漿子共振特性製造CdSe/ZnS量子點的光學異向性們展現一種有效的方式，利用金屬光柵表面電漿子共振的特性控制CdSe/ZnS量子點的光學異向性。並且發現透過我們的設計，可以把CdSe/ZnS量子點沒有極化性的螢光和拉曼散射控制成很強的光學異向行為。而整個機制可以用金屬光柵的表面電漿子模態和量子點螢光發光共振的原理來解釋。這在用量子點製成的光電元件上，可以是一個很好的發展和應用。.可選擇波長的熱輻射發射器：以光子晶體和表面電漿子結合的原理製程們把一維光子晶體夾在兩片銀薄膜上面，製作成一個可選擇波長的熱輻射發射器，而上層的銀薄膜是由六角形週期穿孔洞的陣列組成。因為光子晶體的特性，選擇性的熱輻射會在一維的光子晶體內產生並且透過上層設計的表面電漿子震盪模態發射出去，並且發現光子能隙漏光的模態和表面電漿子震盪模態接近時會增強熱輻射的發射強度。利用光子晶體和表面電漿子製成的熱輻射器是可以藉由這些模態來選擇發射波長的，這項技術可以應用在高功率遠紅外光源發展上。.大角度電致螢光光譜的ZnO奈米瓶子/GaN發光二極體們報告一個由p型GaN和ZnO奈米瓶子組成發波長405奈米紫色光的發光二極體。擁有良好結晶品質和排列整齊的奈米瓶子是由一個特殊倒置在攝氏450度環境的化學氣相沈積方法中製成。發光大角度的照明在我們日常生活中常見，運用我們奈米瓶子波導的特性，可以很容易在發光二極體上面製作大角度的發光光源。In this thesis, we have performed several studies on the effects of periodic arrays and surface plasmons on the optical properties of semiconductors, including the fabrication of Si based two-dimensional photonic crystals with a large full band gap, the creation of optical anisotropy of CdSe/ZnS quantum dots with metal grating, the fabrication of a selective thermal emitter with combining a perforated metal film and one-dimensional photonic crystals, and ZnO nanobottles light emitting diodes with wide angle electroluminescence.. Connected hexagonal photonic crystals with largest full band gap two-dimensional photonic crystal with a large full band gap has been designed, fabricated, and characterized. The photonic crystal design was based on a calculation using inverse iteration with multigrid acceleration. The fabrication of the photonic crystal on silicon was realized by the processes of electron-beam lithography and inductively coupled plasma reactive ion etching. It was found that the hexagonal array of circular columns and rods has an optimal full photonic band gap. In addition, we show that a larger extraction of light from our designed photonic crystal can be obtained when compared with the frequently used photonic crystals reported previously. Our designed PC structure therefore should be very useful for creating highly efficient optoelectronic devices.. Creating optical anisotropy of CdSe/ZnS quantum dots by coupling to surface plasmon polariton resonance of a metal gratingn efficient method that can be used to control the optical anisotropy of CdSe/ZnS quantum dots by coupling to the surface plasmon polariton resonance of a metal grating has been demonstrated. It is found that the unpolarized emission and Raman scattering signals arising from CdSe/ZnS quantum dots can be manipulated and exhibit a strong anisotropic behavior based upon our strategy. The optical anisotropy is interpreted in terms of the coupling between the directional surface plasmon of metal grating and the emitted light beam of quantum dots. Due to the importance of quantum dots in optoelectronic devices, our new approach should be useful for future application.. A thermal emitter with selective wavelength: based on the coupling between photonic crystals and surface plasmon polaritons thermal emitter with selective wavelength has been demonstrated, in which the dielectric layers formed one-dimensional photonic crystals are sandwiched between two Ag films. The top Ag film is perforated periodically with hexagonal hole array. The selected thermal radiation of the photonic crystals resonates between two metal films, and surface plasmon polaritons are generated on the top Ag and converted to light radiation. It is found that when leakage modes adjacent to the optic band gap of photonic crystals meet the resonant modes of surface plasmom polaritons, an enhanced thermal emission with maximum intensity can be obtained. The hybrid photonic and plasmonic thermal emitters are selective, which should be very useful for the creation of high power infrared light sources.. Wide angle electroluminescence from ZnO nanobottles/GaN light emitting diodeside angle electroluminescence of bright violet light with a peak wavelength of 405 nm from light emitting diodes composed of p-GaN/ZnO nanobottles has been reported. The fabrication of well aligned nanobottles with excellent crystalline quality was achieved by chemical vapor deposition at temperature as low as 450 ºC with a specially designed upside-down arrangement of substrate configuration. Wide angle light sources are essential in our daily life, and with the geometry of nanobottles waveguides, it is very easy to realize such a practical application.Contents Introduction………………………………………………....01.1 Manipulating light in the dielectric and metallic materials…….011.2 Overview of the thesis…………………………………………… 03 Theory of photonic crystals and surface plasmons……… 06.1 Introduction of photonic crystals…………………………………06 2.1.1 Wave equations and eigenvalue problems…………………….. 11 2.1.2 The plane-wave expansion method…………………………….14 Reference of section 2.1 .....………………………………………...192.2 Introduction of surface plasmons………………………………...22 2.2.1 Surface plasmons on smooth surfaces (Semi-infinite system)......23 2.2.2 Plasmonic (application of surface plasmons)……………………30 Reference of section 2.2 …………………………………………….34 Manufacture technology and optical measurement of materials……………………………………………………..363.1 Fabrication method………………………………………………..36 3.1.1 Photolithography………………………………………………...36 3.1.1.1 Introduction…………………………………………………..36 3.1.1.2 The photolithographic process…………………………..…...36 3.1.2 E-beam lithography……………………………………………..41 3.1.2.1 The system of ELS-7500EX…………………………………41 3.1.2.2 Electron energy deposition in matter………………….……..44 3.1.3 Reactive ion etching………………………………………...…..46.1.4 Evaporation (deposition)………………………………………..49 Reference of section 3.1 ………..………………………………..….513.2 Techniques of measurement……………………………………....52 3.2.1 Fourier transform infrared spectroscopy (FTIR)………………...52 3.2.2 Photoluminescence (PL)…………………………………………56 3.2.3 Raman scattering……………………………………………...…59 Reference of section 3.2 ……………………………………………63 Connected hexagonal photonic crystals with largest full band gap…………………………………………………….644.1 Introduction……………………………………………………….644.2 Calculation and fabrication………………………………………654.3 Experimental measurements……………………………………..704.4 Results and discussion…………………………………………….724.5 Summary…………………………………………………………..79 Reference of chapter 4 ……………………………………………...80 Creating optical anisotropy of CdSe/ZnS quantum dots by coupling to surface plasmon polariton resonance of a metal grating………………………………………………………825.1 Introduction………………………………………………………825.2 Experiment………………………………………………………..835.3 Results and discussion…………………………………………....875.4 Summary………………………………………………………….93 Reference of chapter 5 ……………………………………………..94 A thermal emitter with selective wavelength: based on the coupling between photonic crystals and surface plasmon polaritons…………………………………………………..986.1 Introduction………………………………………………………986.2 Experiment…………………………………………………….....996.3 Results and discussion………………………………………….1026.4 Summary………………………………………………………...114 Reference of chapter 6 ……………………………………………115 Wide angle electroluminescence from ZnO nanobottles/GaN light emitting diodes……………………………………...1187.1 Introduction……………………………………………………..1187.2 Experiment……………………………………………………….1197.3 Results and discussion……………………………………………1217.4 Summary…………………………………………………………..133 Reference of chapter 7 ……………………………………………...134 Conclusion………………………………………………….13

Single Headlamp with Low- and High-Beam Light

Generally, automobiles are typically equipped with separate headlamp lanterns for generating low- and high-beam light. Compared with separate headlamp lanterns, a single headlamp producing both low- and high-beam light can be more compact and have less mechanical complexity. The single headlamp structure has become a main emphasis of research that manufacturers will continue to focus great efforts on in the future. A novel design of a single headlamp generating both low- and high-beam light is proposed in this study. The proposed headlamp consists of a compound ellipsoidal reflector, a baffle plate, a condenser lens, and LED array devices generating low- and high-beam light. The compound ellipsoidal reflector comprises a primary ellipsoidal reflector for generating low-beam light and a secondary ellipsoidal reflector for generating high-beam light. Monte Carlo ray tracing simulations were performed to confirm the optical characteristics of the proposed design. A prototype of the proposed headlamp was also fabricated and assembled to verify the design’s effectiveness. The simulated and measured illuminance distributions of the low-beam and high-beam light had the desired light patterns. Moreover, all the simulated and measured illuminances of each point and line met the ECE R112 regulation for low-beam and high-beam light. The proposed headlamp in this study is feasible for the application of single headlamp generating both low- and high-beam light

Anti-Inflammatory and T-Cell Immunomodulatory Effects of Banana Peel Extracts and Selected Bioactive Components in LPS-Challenged In Vitro and In Vivo Models

Banana peel (BP) has potent antioxidative properties; however, the anti-inflammatory potential of BP and its related bioactive components remain unclear. This study used solvent extraction and gas chromatography–mass spectrometry (GC–MS) to isolate and identify the active fractions and compounds in BP. BP was extracted with 95% ethanol (BP-95E) and partitioned with an ethyl acetate (EA) and water mixture to obtain the BP-95E-EA and BP-95E-H2O fractions. The BP-95E-EA fractions were further partitioned with n-hexane (Hex) and methanol (MeOH) mixtures to obtain BP-95E-EA-Hex and BP-95E-EA-MeOH subfractions, and the BP-95E-H2O fractions were partitioned with n-butanol (BuOH) to obtain BP-95E-H2O-BuOH subfractions and the H2O residual. The results show that the BP-95E-H2O-BuOH subfractions exhibited the most potent inhibition of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) secretion while down-regulating inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. In this active subfraction, five non-polyphenol compounds were identified, namely, 5-hydroxyethyl furfural (5-HMF), guaiol, oleic acid, linoleic acid, and oleamide. 5-HMF, guaiol, and oleamide were the most effective at suppressing IL-6 and TNF-α secretion. The in vivo immunomodulatory action of BP was evaluated in an LPS-induced endotoxemia model of BALB/c mice. Oral administration of BP-95E-H2O-BuOH extracts (42 and 166 mg/kg b.w.) for two weeks lowered the serum levels of IL-6 and TNF-α and normalized the activated T-cell population, as evidenced by an increase in CD3CD69 and decrease in IFN-γ/IL-4 (Th1/Th2) in mice with systemic inflammation. Our findings reveal that BP exhibits anti-inflammatory and T-cell immunomodulatory effects that may contribute to delaying endotoxemia-associated disorders