Hu, Jianliang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 88-105). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Long range order (LRO) is one of the most important properties of physics systems, especially for a strongly correlated system. In this thesis, the long range order in a few strongly correlated systems is investigated both rigorously and numerically. / Magnetic orders in the two-dimensional periodic Anderson model (PAM) were investigated in the project. Several numerical methods including exact diagonalization, mean field methods and the constrained path Monte Carlo (CPMC) method were used here. We studied the effect of the dispersion of the impurity band on the magnetism and gave estimated phase diagrams on the band filling and impurity chemical potential plane, by comparing the ground state energies and by studying the Fourier transformation of the spin-spin correlations. / The Neel long range order in various quantum spin models was studied. A spatially anisotropy antiferromagnetic Heisenberg system was studied and a critical point Jup⊥S was obtained. When J⊥ is larger than Jup⊥S , the Neel long range order was proved to exist in the ground state of the system. Then an onsite single-ion anisotropy D-term was imposed on the above system and its effect on the existence of the long range order was studied. We obtained a critical line on the DJ⊥ plane such that above which the long range order exists. To get insight into the long range order in the two-dimensional isotropic Heisenberg model, the XXZ model and the Heisenberg system with next nearest neighbors interaction were studied. For the XXZ model, two critical couplings DeltaXY and DeltaIsing were obtained such that when 0 ≤ Delta ≤XY or Delta ≥ DeltaIsing, the Neel order appears. For the antiferromagnetic Heisenberg model with next nearest neighbors interaction both spin S = 1/2 and S = 1 were studied. For S = 1/2, a critical next nearest neighbors ferro-coupling Jc2 was obtained such that when J2 ≤ Jc2 , the Neel long range order appears, while for S = 1 an improved Jc2 was obtained such that when J2 ≤ Jc2 the Neel order still exists even with frustration. / Wang Yongqiang = 强关联系统中的长程序 / 王永强. / "June 2005." / Adviser: Haiqing Lin. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3861. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 156-162). / 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. / Text in English; abstracts in English and Chinese. / School code: 1307. / Wang Yongqiang = Qiang guan lian xi tong zhong de chang cheng xu / Wang Yongqiang.

No description available.

Rigid rotor models were investigated with constraints from data for even-even nuclei. Specifically, from precision gamma-ray intensity measurements for 166-Er (from 166m-Ho and 166-Tm beta decays); from B(E2) systematics; and for 186,188,190,192-Os matrix element data.

Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (p. 208-215).

Thesis (Ph. D.)--Florida State University, 2003. / Advisor: Dr. Peng Xiong, Florida State University, College of Arts and Sciences, Dept. of Physics. Title and description from dissertation home page (viewed Apr. 9, 2004). Includes bibliographical references.

Shaped pulses can be used for uniform spin-1 excitation. The effects of the pulses on spin-1 excitation is seen as distortion of two types: phase distortions and amplitude distortions. By reducing the distortions a spin-1 excitation becomes more uniform. In the case of time-symmetric shaped pulses, spin-1 excitation is free of phase distortions. The spin-1 excitation in that case can be made uniform over a larger frequency bandwidth. The number of possible shaped pulses is so large that a computer-aided search is needed to find the desirable shaped pulses. A theoretical analysis is used to find the connection between a shaped pulse and the corresponding spin-1 excitation. The theoretical analysis in density matrix formalism gives the spin-1 excitation in closed-form expressions that are too complicated. In such a case the connection between a shpaed pulse and spin-1 excitation is not straightforward. A brute-force search for a desirable shaped pulse can consume too much computer time and thus time the scope of the search. By using the formalism of quaternions in the theoretical analysis, spin-1 excitation is presented in simple closed form expressions. It is then shown tht if the choice is limited to time-symmetric shaped pulses then these closed form expressions become much simpler. It is also shown that a spin-1 excitation is free of phase distortions in that case. These simple closed form expressions can be used as the building blocks of a much more concise program code for the computer aided search. As a result a computer aided search for a desirable shaped pulse becomes much faster in speed and larger in scope. More shaped pulses for improved spin-1 can be found. / xiii, 99 leaves : ill. ; 28 cm.

No description available.

The phospholipid membrane is a self-assembled, dynamic molecular system that may exist alone in association with only water, or in complex systems comprised of multiple lipid types and proteins. In this dissertation the intra- and inter-molecular forces responsible for the atomistic, molecular and collective equilibrium structure and dynamics are studied by nuclear magnetic resonance spectroscopy (NMR). The multinuclear NMR measurements and various experimental techniques are able to provide data that enable the characterization of the hierarchical spatio-temporal organization of the phospholipid membrane. The experimental and theoretical studies conducted target membrane interactions ranging from model systems composed of only water and lipids, to multiple component domain forming membranes that are in association with peripheral and trans-membrane proteins. These measurements consisit of frequency spectrum lineshapes and nuclear-spin relaxation rates obtained using 2 H NMR, 13 C NMR, 31 P NMR and 1 H NMR. The changes of these experimental observables are interpreted within a statistical thermodynamic framework that allows the membrane structure, activation energies, and correlation times of motion to be determined. The cases presented demonstrate how fundamental principles of NMR spectroscopy may be applied to a host of membranes, leading to the biophysical characterization of membrane structure and dynamics.

The spin of the proton is thought to be produced by several constituents including quarks, antiquarks, and gluons. It has been the goal of the spin physics program at RHIC (Relativistic Heavy Ion Collider) to measure the contribution from gluons and various sea quarks to the proton spin. The Forward GEM Tracker (FGT) is a detector in STAR (Solenoidal Tracker at RHIC), which is one of two large experiments and is located at the RHIC collider at Brookhaven National Laboratory. The FGT serves to locate the position of forward-going charged particles, and it will be instrumental in observing the trajectories of decay leptons from W bosons, created by the interaction of the quark of one proton and the antiquark of another in a proton-proton collision. This position information will be helpful in determining the contribution of the quarks and antiquarks to the spin of the proton. This analysis investigates the initial performance of the FGT. Studies were conducted using cosmic-ray test data collected during the detector’s construction and more recent data from polarized-proton collisions within STAR. The goals of these studies were: to see if the detector works, see how well it works, check for any odd behavior, and optimize the performance of the detector. / Department of Physics and Astronomy