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Many novel materials, such as the vanadates MgV 2O5, the cuprates SrCu 2O3, conducting polymers and organic salts which involve longer-range Coulomb interactions, can be modeled by the extended Hubbard model. In this thesis, we applied the strong-coupling perturbation theory to study a generalized extended Hubbard model characterized by the inter-chain electron hopping t' and the inter-chain nearest-neighbor interaction V' as well as the on-site interaction U, the intra-chain nearest-neighbor interaction V and the intra-chain electron hopping t at strong coupling limit for quarter and half band fillings. / The early strong coupling perturbation expansion was only up to the fourth order in t/U and t/V expansion, which is good for the large values of interaction, U/t > 10. However, for real physical systems, the reasonable range of U/t should be from 4 to 10. In order to investigate the physical systems more accurately, we worked out a perturbation expansion up to the sixth order, hence obtained an effective Hamiltonian in t/U, t/V, t/V', t'/U, t'/V and t'/V' expansion for the extended Hubbard model in half and quarter band filings. The effective Hamiltonian obtained only contains the spin-spin correlation terms. For the half-filled band, we calculated the four spin-spin correlation terms and applied the first and second nearest-neighbor correlation of the linear Heisenberg model obtained by Hulthen and Takahashi and the third nearest-neighbor correlation obtained by Kazumitsu Sakai's group to calculate the ground state energy for the 1-D extended Hubbard chain with the realistic Coulomb interactions, U/t ranges from 4 to 14 and V/t ranges from 0 to 2 respectively. For the quarter-filled case, we worked out the effective Hamiltonian for the 1-D and the 2-D cases and calculated the spin-spin correlation functions by the spin-wave theory. We calculated the ground state energy with the same ranges of the on-site interaction input in the half-filled case and the V/t ranges from 1.5 to 4.0 for the 1-D, the quasi 2-D (t > t', t'/V ∼ t/V) and the isotropic 2-D (t = t', V = V') case respectively. In order to check the validity of the perturbation expansion, we proceeded numerical calculations of the ground state energy by exact diagonalization for the same values of U, V, t, V' and t' for both the half-filled and the quarter-filled cases. / Lee Wing Fai = 強耦合擴展 Hubbard模型之微擾計算 / 李榮輝. / "August 2005." / Adviser: Lin Hai Qing. / Source: Dissertation Abstracts International, Volume: 67-01, Section: B, page: 0323. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 157-160). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / School code: 1307. / Lee Wing Fai = Qiang ou he kuo zhan Hubbard mo xing zhi wei rao ji suan / Li Ronghui.

As the performance of computers has improved dramatically since the 1990s, many interesting photonic crystal properties have been theoretically and experimentally discovered. For example, the strong coupling between photonic crystal cavities was revealed in the 2000s; many groups have successfully fabricated these cavities and verified strong coupling experimentally using silicon. In this thesis, instead of using silicon, we present new results on photonic crystals made by thin indium tin oxide (ITO) layers. Compared to silicon, ITO is not an ideal material to make a photonic crystal because of its comparatively low refractive index and limited transparency. However, it is an interesting model material for experiments in photoemission electron microscopy (PEEM). ITO has a high conductivity that mitigates surface charge-up in an electron microscope and allows electron emission after 2-photon absorption with visible light. We are interested in PEEM because it enables the visualization of the propagation of light with nanometer resolution, i.e., below the optical diffraction limit. In this thesis, we theoretically study ITO photonic crystals in one or two-dimensions with the help of the finite-difference time-domain (FDTD) software. We analyze the electromagnetic field distribution in a manner that the field distributions can directly be compared to experimental PEEM results. We also simulate the strong coupling effect between neighboring cavities and illustrate it in terms of the classical oscillator model.

This thesis presents the results of a study into the mechanics of stresses in adhesive layer and the failure of adhesively bonded lap joints. A brief survey was made of the existing methods on the stress analysis of adhesively bonded lap joints. Following this is a discussion of the mechanics of adhesively bonded lap joints. The existence of stresses and factors affecting these stresses are presented in physical terms. A new method is presented for the determination of bending moments at the ends of the overlap for single lap joints. This method is accurate for joints with either identical or different adherends. A new procedure combining the analytical and numerical methods was proposed to obtain stresses in the adhesive layer accurately and efficiently. The reason why analytical methods yield somewhat hall the real peel stresses in the adhesive layer in double lap joints has been establis'hed. Some improvements in the determination of peel stresses in the adhesive layer in double lap joints have been made. A three dimensional stress analysis was carried out to study the stress distribution across the joint- width. An intuitive and numerical study was made into the mechanics of the longitudinal stresses in the adhesive layer. An elastic-plastic stress and strain analysis. has been performed with FEM on joints bonded with radii adherends to study the effect of the rounding of the adherend corners on the stress distribution in the adhesive layer. Some study into the failure process and failure modes were performed. Tests were made on both double and single lap joints. Finally. the failure criteria concerning strength predictions of adhesively bonded joints were reviewed. A, new criterion was proposed for the prediction of joint strength

Procedures for the synthesis of four-bar kinematic linkages with approximate portions of their coupler point curves specified are developed. The necessary equations are derived and computer programs using these equations which have been integrated into a complete synthesis procedure are set forth. If a body, or a mechanism link, is in plane motion with two points on the body constrained to particular paths, the nature of the paths of all other points on the link is known. The functional behavior of the radius of curvature of the path of any point on the link and the derivatives of the radius of curvature with respect to some displacement parameter may be ascertained. It is then possible to approximate the motion of the link by approximating the behavior of the derivatives of the radius of curvature. A procedure allowing one degree of freedom in locating the coupler point, such that the zeroes of the first derivative of the radius of curvature are approximated, is presented for the case of an approximately straight coupler point path. Another procedure permitting two degrees of freedom in the coupler point specification is shown for both straight and circular coupler curves. In the case of the two degrees of freedom procedure, both the first and second derivatives of the radius of curvature are specified with respect to the loci of the zeroes of the derivatives. For each synthesis procedure, examples are presented. The computer program listings and sample outputs for each example are shown. / Ph. D.

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Thesis (M.S. in materials science and engineering)--Washington State University, May 2007. / Includes bibliographical references.

This article reviews the properties and applications of a series of liquid crystal solvents for NMR spectroscopy of, particularly, biological compounds with emphasis placed on n-alkyl-poly(ethylene glycol)/n-alkyl alcohol, the most versatile liquid crystal system hitherto discovered. The applications of this solvent to mixtures, polymers and proteins are also mentioned.

One of the more formidable challenges in the synthesis of complex organic molecules remains the efficient formation of carbon-carbon bonds. The development of a broad class of reactions to achieve this goal involves the addition of carbon based nucleophiles to carbonyl and imine compounds. Until recently, classical approaches to carbon-carbon bond formation generally required the use of stoichiometric pre-formed organometallic reagents to serve as nucleophiles, which translate into stoichiometric organometallic byproducts. In an effort to minimize nucleophile pre-activation and byproduct formation, our lab has developed efficient methods for carbonyl and imine additions via in situ formation of alkyl metal nucleophiles from π-unsaturates. The research reported herein describes our advances in an assortment of transition metal-catalyzed carbon-carbon bond forming reactions mediated by transfer hydrogenation, including regioselective hydrohydroxymethylation, hydrohydroxyfluoroalkylation, and hydroaminomethylation. Additionally, the investigation of regioselective carbonyl vinylation is reported. / text

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