Il y a beaucoup de mystères entourant les cuprates supraconducteurs. Certaines expériences montrent que de l'ordre de charge serait présent dans les mêmes conditions que la supraconductivité. Les phénomènes seraient peut-être en compétition. On tentera de modéliser l'ordre de charge à l'aide du modèle de Hubbard. Des méthodes d'amas seront utilisées pour résoudre approximativement le modèle. Ensuite, on tente de mettre l'ordre de charge en compétition avec la supraconductivité pour en voir les effets.

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published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

本論文共一冊，內含五章廿二節，約五萬餘字。主要以國內公民營企業主管為研究對 象，利用便利抽樣方式，共得三百五十份樣本，以探討下列問題： １．組織內主管要向部屬提出要求或建議時，較常使用那些方式或技巧。 ２．瞭解各類方法的使用頻率和效果與主管的人格特性，人口變項、組織特性之間的 關係。 ３．探討各類方法對何種對象較為有效。 ４．瞭解主管影響部屬時，其主要目的是為公事上的理由或私人的協助，還是有其他 的目的。

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In the past decade, charge-coupled devices (CCDs) have rapidly become the astronomical imaging detector of choice for the visible and near-IR spectral regions. There are, however, several problems which have greatly reduced the availability of sufficient quality CCDs to the astronomical community. These include the low blue and ultraviolet quantum efficiency of thick devices, the lack of properly thinned devices, warped imaging surfaces, interference fringing, and the small size of the detectors themselves compared to telescope focal planes. This dissertation presents methods which can be used to optimize CCDs obtained from various manufacturers for astronomical observations. A new thinning technique which produces an optically flat surface across an entire CCD is demonstrated. A mounting technique which maintains a flat and stable imaging surface for thinned devices by bonding the CCD backside against a transparent glass support substrate is also demonstrated. Bump bonding of CCDs onto a silicon support before thinning is discussed as a future mounting/thinning technique. The design of antireflection coatings for the near-UV through near-IR spectral regions is explained and demonstrated on silicon diodes, allowing quantum efficiencies as high as 90% to be obtained. The reduction of interference fringing amplitudes by as much as 70% in the red and near-IR with AR coatings is also discussed. And finally, the design of CCD focal plane mosaics using the optimization techniques presented is discussed.

The research described in this dissertation conclusively demonstrates the superior qualitative and quantitative performance of spectroscopic systems which employ a new class of optical detectors--charge transfer device (CTD) detectors. An overview of the operation and characteristics of these detectors, as well as theoretical models predicting their performance are presented. The evaluation of a unique prototype single element CID detector, a commercially available linear CCD detector, and a prototype two-dimensional CCD detector are described. Outstanding characteristics include the ability of the single element CID to quantitate photon fluxes ranging over eleven orders of magnitude, a quantum efficiency of the linear CCD in excess of 90%, and a read noise of the two-dimensional CCD of under 5 electrons. In addition, the use of the linear CCD for molecular fluorescence spectroscopy is demonstrated. A direct comparison of CCD and CID detection for atomic emission spectroscopy using a custom echelle system is described. The second part of these investigations focus on the design of spectrometers compatible with the format of these multichannel detectors. While a large number of spectrometer designs exist, the spectrometer and detector combination which produces the highest possible signal-to-noise ratio (SNR) spectra for a given experimental system is almost always desired. The investigations into optimum spectrometer design have led to the use of a unique spatial interferometer system. The performance of a common path interferometer using a linear charge-coupled device detectors is presented and compared to conventional dispersive systems. The throughput, resolution, and other practical factors are discussed. The common path system has a much larger light gathering ability compared to dispersive systems; however, spatial interferometry suffers from the multiplex disadvantages encountered with other forms of UV/Vis interferometry. A unique crossed interferometric dispersive arrangement allows the simultaneous acquisition of the spectral information while greatly reducing these multiplex disadvantages. Preliminary work on the crossed interferometric system is presented demonstrating significant reduction of these multiplex disadvantages.

Speckle noise is an integral part of any laser projection display because it is the nature of laser (coherent) illumination to form interference patterns with high visibility. The granularity of the image due to the speckle formed on the viewer's retina degrades the image quality, thus stimulating the need for speckle reduction techniques applied to laser displays. An instrument to measure image plane speckle contrast was built based on a linear CCD detector array interfaced to an LSI-11 microcomputer. Speckle reduction techniques were then evaluated by comparing the contrast obtained with each method. The effect of the spatial frequency response (MTF) on the measured contrast was studied, along with the statistical significance of the measurement which is limited by the finite sample space of 1024 detector pixels per CCD frame. The lowering of the contrast due to the array MTF can be minimized by working at extremely high F numbers (> 100). The sample space can be widened by taking more than one frame of data and treating all the frames as a single data set. Techniques to reduce speckle noise in laser displays fall into two broad categories: reducing the coherence of light forming the speckle, and incoherently adding multiple uncorrelated (or partially correlated) speckle patterns. The first technique (effective only for monochromatic displays) was implemented by coating a screen with various dyes, phosphors, or fluorescent paints. Using the 514 nm line from an Argon laser, the contrast can be reduced by almost 30% by spraying a thin layer of fluorescent paint on the screen. More speckle reduction can be achieved with an accompanying loss in image brightness. The second technique involved creating a multiplicity of partially correlated speckle patterns that appear from the same position on the screen over the integration period of the eye. The different speckle patterns are produced by changing the angle of illumination while keeping a portion of the laser spot focused on the same point on the screen. The scan angle method (applicable to multi-color displays), can be implemented by properly synchronizing an acousto-optic modulator with the scan optics, and imaging the modulator on the screen. Using a beaded screen and a reasonable laser dither of 10 millirads, the contrast can be reduced by half.

Correlated double sampling (CDS) is a widely used signal processing technique for removal of the Nyquist (reset) noise which is associated with charge sensing circuits employed in a solid state imager. In this thesis work, the power spectral density at the output of a correlated double sampling circuit with first-order low-pass filtered white noise at the input is calculated. A circuit constructed with discrete elements is made to simulate the output stage of a charge-coupled device (CCD). A low-pass filtered wide-band noise from a noise generator is added to the reset reference level when the output signal from this simulator is sampled by the correlated double sampling technique. The experiment measurements show that only about 10% of the noise power measured by simple sampling is obtained when CDS is employed. An autoregressive (AR) model is assumed to fit the sampled data and a recursive algorithm, based on least-squares solutions for the AR parameters using forward and backward linear prediction, is adopted for spectrum estimation. Some conclusions on choosing the bandwidth of the low pass filter for optimum operation is also included.