Wang Chengqing. / "November 2004." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

Chapter 1 briefly introduces the background, problems, applications as well as recent progress of the nanobubbles research. The relationship between the formation/stabilization of nanobubbles and the long-rang structures of water molecules, particularly the restructuring of water molecules at the water/gas interface, are emphasized. / Chapter 2 introduces the theories of static and dynamic light scattering and Zeta-potential measurements as well as the details of the instrument set-up. In this chapter, the fundamental equations of the scattering theory are figured out basis on the quasi-classical electrodynamics and combination of the statistical mechanics as well as molecular dynamic theory. Finally, the statistical properties of photon counting are discussed. / In chapter 3, aqueous solutions of tetrahydrofuran, ethanol, urea and alpha-cyclodextrin were studied by a combination of static and dynamic laser light scattering (LLS). In textbooks, these small organic molecules are soluble in water so that there should be no observable large structures or density fluctuation in either static or dynamic LLS. However, a slow mode has been consistently observed in these aqueous solutions in dynamic LLS. Such a slow mode was previously attributed to some large complexes or supramolecular structures formed between water and these small organic molecules, Our current study reveals that it is actually due to the existence of small bubbles (∼100 nm in diameter) formed inside these solutions. Our direct evidence comes from the fact that it can be removed by repeated filtration and regenerated by air purging. Our results also indicate that the formation of such nanobubbles in small organic molecules aqueous solutions is a universal phenomenon. Such formed nanobubbles are rather stable. The measurement of isothermal compressibility confirms the existence of a low density micro-phase, presumably nanobubbles, in these aqueous solutions. Using a proposed structural model, i.e., each bubble is stabilized by small organic molecules adsorbed at the gas/water interface, we have, for the first time, estimated the pressure inside these nanobubbles. / In chapter 4, by using a combination of laser light scattering (LLS) and zeta-potential measurements, we investigated effects of salt concentration and pH on stability of the nanobubbles in alpha-cyclodextrin (alpha-CD) aqueous solutions. Our LLS results reveal that the nanobubbles are unstable in solutions with a higher ionic strength, just like colloidal particles in an aqueous dispersion, but become more stable in alkaline solutions. The zeta-potential measurement shows that the nanobubbles are negatively charged with an electric double layer, presumably due to the adsorption of negative OTT ions at the gas/water interface. It is this double layer that plays dual roles in the formation of stable nanobubbles in aqueous solutions of water-soluble organic molecules; namely, it not only provides a repulsive force to prevent the inter-bubble aggregation and coalescence, but also reduces the surface tension at the gas/water interface to decreases the internal pressure inside each bubble. / In chapter 5, the addition of salt can induce slow coalescence of nanobubbles (∼100 nm) in an aqueous solution of alpha-cyclodextrin (alpha-CD). A combination of static and dynamic laser light scattering was used to follow the coalescence. Our results reveal that its kinetic and structural properties follow some scaling laws; namely, the average size (<zeta>) of nanobubbles is related to their average mass (<M>) and the coalescence time (t) as <M> <zeta>dr and <zeta> ∼ tgamma with two salt-concentration dependent scaling exponents (df and gamma) For a lower sodium chloride concentration (C NaCl = 40 mM), gamma = 0.13 +/- 0.01 and df = 1.71 +/- 0.02. The increase of CNaCl to 80 mM results in gamma = 0.32 +/- 0.01 and df = 1.99 +/- 0.01. The whole process has two main stages: the aggregation and the coalescence. At the lower C NaCl, the process essentially stops in the aggregation stage with some limited coalescence. At higher CNaCl leads the coalescence after the aggregation and results in large bubbles. / In this thesis, the nanobubbles in the aqueous solutions have been studied by using combination of static and dynamic laser light scattering (LLS), isothermal compressibility measurements and Zeta-potential measurements. We found that the nanobubbles extensively exist in aqueous solutions and the interface of each nanobubble is negatively charged. The addition of electrolytes can destabilize such interface to induce the coalescence of nanobubbles. / Jin, Fan. / "Aug 2007." / Adviser: Chi Wu. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1030. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 108). / 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. / Abstract in English and Chinese. / School code: 1307.

by Yubao Zhang. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (p. 138-146). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.

by Kwan Wai Wing Eric. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references. / ABSTRACT / ACKNOWLEDGMENT / LIST OF FIGURES / LIST OF TABLES / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Background --- p.1-1 / Chapter 1.2 --- E-Beam testing and test generation algorithm --- p.1-2 / Chapter 1.3 --- Motivation of this research --- p.1-4 / Chapter 1.4 --- Out-of-kilter Algorithm --- p.1-6 / Chapter 1.5 --- Outline of the remaining chapter --- p.1-7 / Chapter Chapter 2 --- Electron Beam Testing / Chapter 2.1 --- Background and Theory --- p.2-1 / Chapter 2.2 --- Principles and Instrumentation --- p.2-4 / Chapter 2.3 --- Implication of internal IC testing --- p.2-6 / Chapter 2.4 --- Advantage of Electron Beam Testing --- p.2-7 / Chapter Chapter 3 --- An exhaustive method to minimize test sets / Chapter 3.1 --- Basic Principles --- p.3-1 / Chapter 3.1.1 --- Controllability and Observability --- p.3-1 / Chapter 3.1.2 --- Single Stuck at Fault Model --- p.3-2 / Chapter 3.2 --- Fault Dictionary --- p.3-4 / Chapter 3.2.1 --- Input Format --- p.3-4 / Chapter 3.2.2 --- Critical Path Generation --- p.3-6 / Chapter 3.2.3 --- Probe point insertion --- p.3-8 / Chapter 3.2.4 --- Formation of Fault Dictionary --- p.3-9 / Chapter Chapter 4 --- Mathematical Model - Out-of-kilter algorithm / Chapter 4.1 --- Network Model --- p.4-1 / Chapter 4.2 --- Linear programming model --- p.4-3 / Chapter 4.3 --- Kilter states --- p.4-5 / Chapter 4.4 --- Flow change --- p.4-7 / Chapter 4.5 --- Potential change --- p.4-9 / Chapter 4.6 --- Summary and Conclusion --- p.4-10 / Chapter Chapter 5 --- Apply Mathematical Method to minimize test sets / Chapter 5.1 --- Implementation of OKA to the Fault Dictionary --- p.5-1 / Chapter 5.2 --- Minimize test set and optimize internal probings / probe points --- p.5-5 / Chapter 5.2.1 --- Minimize the number of test vectors --- p.5-5 / Chapter 5.2.2 --- Find the optimum number of internal probings --- p.5-8 / Chapter 5.2.3 --- Find the optimum number of internal probe points --- p.5-11 / Chapter 5.3 --- Fixed number of internal probings/probe points --- p.5-12 / Chapter 5.4 --- True minimum test set and optimum probing/ probe point --- p.5-14 / Chapter Chapter 6 --- Implementation and work examples / Chapter 6.1 --- Generation of Fault Dictionary --- p.6-1 / Chapter 6.2 --- Finding the minimum test set without internal probe point --- p.6-5 / Chapter 6.3.1 --- Finding the minimum test set with optimum internal probing --- p.6-10 / Chapter 6.3.2 --- Finding the minimum test set with optimum internal probe point --- p.6-24 / Chapter 6.4 --- Finding the minimum test set by fixing the number of internal probings at 2 --- p.6-26 / Chapter 6.5 --- Program Description --- p.6-35 / Chapter Chapter 7 --- Realistic approach to find the minimum solution / Chapter 7.1 --- Problem arising in exhaustive method --- p.7-1 / Chapter 7.2 --- Improvement work on existing test generation algorithm --- p.7-2 / Chapter 7.3 --- Reduce the search set --- p.7-5 / Chapter 7.3.1 --- Making the Fault Dictionary from existing test generation algorithm --- p.7-5 / Chapter 7.3.2 --- Making the Fault Dictionary by random generation --- p.7-9 / Chapter Chapter 8 --- Conclusions / Chapter 8.1 --- Summary of Results --- p.8-1 / Chapter 8.2 --- Further Research --- p.8-5 / REFERENCES --- p.R-1 / Chapter Appendix A --- Fault Dictionary of circuit SC1 --- p.A-1 / Chapter Appendix B --- Fault Dictionary of circuit SC7 --- p.B-1 / Chapter Appendix C --- Simple Circuits Layout --- p.C-1

No description available.

Ling, Chi Yeung = 作高能量密度物理研究的一種新型強離子束加速器的模擬 / 凌子陽. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (p. 111-114). / Abstracts in English and Chinese. / Ling, Chi Yeung = Zuo gao neng liang mi du wu li yan jiu de yi zhong xin xing qiang li zi shu jia su qi de mo ni / Ling Ziyang. / Chapter 1 --- Introduction --- p.1 / Chapter 2 --- Background --- p.7 / Chapter 2.1 --- High Energy Density Physics and Warm Dense Matter --- p.7 / Chapter 2.1.1 --- Definition of HEDP and WDM --- p.7 / Chapter 2.1.2 --- The physics of WDM --- p.9 / Chapter 2.1.3 --- Advantages of the ion beam approach --- p.10 / Chapter 2.2 --- Intense low energy ion beam machines requirements for NDCX-II --- p.12 / Chapter 2.3 --- Neutralized Drift Compression Experiment (NDCX) --- p.14 / Chapter 2.3.1 --- Neutralized Transport Experiment (NTX) --- p.15 / Chapter 2.3.2 --- The first NDCX --- p.18 / Chapter 2.4 --- Accelerator architectures proposed for NDCX-II --- p.20 / Chapter 2.4.1 --- Radio Frequency Linear Accelerator (RF Linac) --- p.20 / Chapter 2.4.2 --- Electrostatic accelerator --- p.23 / Chapter 2.4.3 --- Drift Tube Linac (DTL) --- p.23 / Chapter 2.4.4 --- Linear Induction Accelerator (induction linac) --- p.24 / Chapter 2.5 --- Pulse Line Ion Accelerator --- p.25 / Chapter 2.6 --- Review on tests of Pulse Line Ion Accelerator --- p.30 / Chapter 2.7 --- Simulation codes --- p.32 / Chapter 2.7.1 --- 3-D Electromagnetic code MAFIA --- p.33 / Chapter 2.7.2 --- Particle-in-cell code WARP --- p.35 / Chapter 2.8 --- Envelope equation of ion beam and beam diagnostics --- p.37 / Chapter 3 --- Investigations on insulator breakdown in the PLIA --- p.40 / Chapter 3.1 --- Modeling in MAFIA --- p.40 / Chapter 3.2 --- Scaling Law --- p.42 / Chapter 3.3 --- Investigation of different frequency modes near insulator surface --- p.46 / Chapter 3.4 --- Standing wave effect in PLIA --- p.50 / Chapter 3.5 --- Conclusion --- p.52 / Chapter 4 --- PLIA based design for the second Neutralized Drift Compression Experiment --- p.55 / Chapter 4.1 --- The injector --- p.56 / Chapter 4.2 --- Pulse Line Ion Accelerator sections --- p.60 / Chapter 4.2.1 --- Basic design strategy --- p.60 / Chapter 4.2.2 --- Simulation results of PLIA sections --- p.69 / Chapter 4.3 --- Neutralized Drift Compression Section --- p.77 / Chapter 4.3.1 --- Drift length --- p.78 / Chapter 4.3.2 --- First focusing solenoid --- p.80 / Chapter 4.3.3 --- Plasma-filled region --- p.84 / Chapter 4.3.4 --- Final focusing solenoid and the best focal point --- p.88 / Chapter 4.3.5 --- Sensitivity to drift length and focusing strength --- p.91 / Chapter 4.4 --- Conclusion --- p.92 / Chapter 5 --- Other Pulse Power Options --- p.94 / Chapter 5.1 --- The injector and the beamline --- p.95 / Chapter 5.2 --- 3-meter electrostatic column --- p.97 / Chapter 5.3 --- Induction linac --- p.100 / Chapter 5.4 --- Hybrid of induction linac and Pulse Line Ion Accelerator --- p.104 / Chapter 5.5 --- Conclusion --- p.107 / Chapter 6 --- Discussions --- p.108 / Chapter 6.0.1 --- Future development of PLIA --- p.110 / Bibliography --- p.111

Xu, Yeming = 水熱法和熱蒸法製備硫化鋅納米结构的電子輻射損傷研究 / 徐業明. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 61-63). / Text in English; abstracts in English and Chinese. / Xu, Yeming = Shui re fa he re zheng fa zhi bei liu hua xin na mi jie gou de dian zi fu she sun shang yan jiu / Xu Yeming. / Abstract --- p.i / 摘要 --- p.ii / Acknowledgment --- p.iii / List of Figures --- p.VII / Table of contents --- p.XI / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- Background of electron beam irradiation --- p.4 / Chapter 2.1 --- Basic principles of electron beam irradiation --- p.4 / Chapter 2.1.1 --- Atomic displacement --- p.5 / Chapter 2.1.2 --- Electron beam sputtering --- p.7 / Chapter 2.1.3 --- Electron beam heating --- p.8 / Chapter 2.1.4 --- Radiolysis --- p.11 / Chapter Chapter 3 --- Instrumentation --- p.13 / Chapter 3.1 --- X-ray photoelectron spectroscopy (XPS) --- p.13 / Chapter 3.1.1 --- Basic principles --- p.13 / Chapter 3.1.2 --- Chemical shifts in x-ray photoelectron spectroscopy --- p.16 / Chapter 3.2 --- The principle of the Scanning Electron Microscopy (SEM) --- p.16 / Chapter 3. 3 --- Transmission Electron Microscope (TEM) --- p.19 / Chapter 3. 3.1 --- Principle of the TEM --- p.19 / Chapter 3.3.2 --- Electron specimen interaction in TEM --- p.21 / Chapter 3.3.3 --- Electron Diffraction --- p.22 / Chapter 3.3.4 --- Contrast --- p.22 / Chapter 3.4 --- Energy dispersive x-ray spectroscopy --- p.23 / Chapter 3.5 --- Elemental mapping using Electron Energy Loss Spectrometer (EELS) --- p.24 / Chapter Chapter 4 --- Structure Degradation of ZnS Nanomaterials Synthesized via Hydrothermal Method --- p.26 / Chapter 4.1 --- Experimental --- p.26 / Chapter 4.2 --- Structure degradation of ZnS nanotubes synthesized via hydrothermal method --- p.27 / Chapter 4.2.1 --- Chemical and structural characterization of the as-synthesized nanotubes --- p.27 / Chapter 4.2.2 --- Crystallinity and structural degradation of the nanosheet under the electron beam irradiation --- p.29 / Chapter 4.2.3 --- Nanotube structure degradation with different experimental parameters --- p.33 / Chapter 4.3 --- Structure degradation of ZnS nanosheets synthesized via hydrothermal method --- p.34 / Chapter 4.3.1 --- Chemical and morphological characteristics of the ZnS nanosheets --- p.34 / Chapter 4.3.2 --- Crystallinity and structural degradation of the nanosheet under the electron beam irradiation --- p.37 / Chapter 4.3.3 --- Nanosheet structure degradation with different experimental parameters --- p.41 / Chapter 4.3.4 --- Discussion on the damage mechanisms --- p.45 / Chapter Chapter 5 --- Structure Degradation of ZnS Nanobelts Synthesized via thermal evaporation Method --- p.48 / Chapter 5.1 --- Experimental --- p.48 / Chapter 5.2 --- Chemical and morphological characteristics of the ZnS nanobelts --- p.49 / Chapter 5.3 --- Crystallinity and structural degradation of the nanobelt under the electron beam irradiation --- p.50 / Chapter 5.4 --- Nanobelt structure degradation with different experimental parameters --- p.55 / Chapter 5.5 --- Discussion on the damage mechanisms --- p.56 / Chapter Chapter 6 --- Conclusion --- p.59 / References --- p.61

No description available.

An analytical and experimental investigation on the shear strength of High Performance Concrete (HPC) beams with vertical shear reinforcement or stirrups was carried out. The analytical work involved developing a theory based on the truss analogy, capable of predicting the response and shear strength of such beams subjected to combined bending moment and shear force.The experimental work comprised forty-eight beam specimens in eight series of tests. Most of the beams were 250 mm wide, 350 mm deep and had a clear span of approximately 2 metres. The largest beam was 250 mm wide, 600 mm deep and had a clear span of 3.1 metres. Test parameters included the concrete cover to the shear reinforcement cage, shear reinforcement ratio, longitudinal tensile steel ratio, overall beam depth, shear span-to-depth ratio and concrete compressive strength. The loading configurations included using one, two or four symmetrically placed concentrated loads on simply supported spans.The theory predicted the shear strength of the beams in the present study well. When beams from previous investigations were included, the theory also gave good prediction of the shear strength. Apart from this, comparisons of shear strength were also made with the predictions by the shear design provisions contained in the Australian Standard AS 3600 (1994), American Concrete Institute Building Code ACI 318-95, Eurocode EC2 Part 1 and Canadian Standard CSA A23.3-94. The AS 3600 method was found to give the best correlation with the test results among all the code methods.

This thesis presents an investigation into the behaviour of a laser beam of finite diameter in a plasma with respect to forces and optical properties, which lead to self-focusing of the beam. The transient setting of ponderomotive nonlinearity in a collisionless plasma has been studied, and consequently the self- focusing of the pulse, and the focusing of the plasma wave occurs. The description of a self-focusing mechanism of laser radiation in the plasma due to nonlinear forces acting on the plasma in the lateral direction, relative to the laser has been investigated in the non-relativistic regime. The behaviour of the laser beams in plasma, which is the domain of self-focusing at high or moderate intensity, is dominated by the nonlinear force. The investigation of self-focusing processes of laser beams in plasma result from the relativistic mass and energy dependency of the refractive index at high laser intensities. Here the relativistic effects are considered to evaluate the relativistic self-focusing lenghts for the neodymium glass radiation, at different plasma densities of various laser intensities. A sequence of code in C++ has been developed to explore in depth self-focusing over a wide range of parameters. The nonlinear plasma dielectric function to relativistic electron motion will be derived in the latter part of this thesis. From that, one can obtain the nonlinear refractive index of the plasma and estimate the importance of relativistic self-focusing as compared to ponderomotive non-relativistic self-focusing, at very high laser intensities. When the laser intensity is very high, pondermotive self-focusing will be dominant. But at some point, when the oscillating velocity of the plasma electron becomes very large, relativistic effects will also play a role in self-focusing. A numerical and theoretical study of the generation and propagation of oscillation in the semiclassical limit of the nonlinear paraxial equation is presented in this thesis. In a general setting of both dimension and nonlinearity, the essential differences between the 'defocusing' and 'focusing' cases hence is identified. Presented in this thesis are the nonlinearity and dispersion effects involved in the propagation of solitions which can be understood by using a numerical routines were implemented through the use of the mathematica program, and results give a very clear idea of this interesting phenomena / Doctor of Philosophy (PhD)