本實驗乃研究超順磁性流體薄膜在通入垂直場後磁顆粒的動力學過程，以及排列的結構、磁鍊的幾何性質。我們使用了兩種創新的方法，分別是改良傳統磁性流體製造方法，避免磁性流體因凝聚而造成干擾；另一個是除了以往以電場或顯微鏡探討磁鍊的性質，使用Rayleigh scattering以及光遮蔽的方法，以CCD量測雷射透射光強度的時變率，改變不同變因(磁場大小、磁性流體樣本厚度、磁性流體濃度)，由於其結構性質影響了透射光強度，故分析透射光強度與諸變因間的關係，並與顯微鏡下的觀察結果比較，做出磁致散射動力學過程詮釋。

將氮、氧、二氧化碳等三種氣體，分別注入水中成為飽和水溶液，將氣體水溶液分裝入塑膠試管中，用超音波洗淨儀以42kHz的頻率振動，可形成奈米氣泡水溶液。利用奈米粒徑及界面電位量測儀測量氣泡的尺寸以及界面電位後，作實驗探討不同尺寸的奈米氣泡對水溶液的磁性、表面張力、折射率、黏滯係數、以及擴散係數等物理性質的影響。 實驗得知:(1)氮和二氧化碳的奈米氣泡的尺寸愈小，水溶液受到的磁力愈大，氧氣則相反。(2)三種氣體水溶液的表面張力都是奈米氣泡尺寸愈小，表面張力愈小。(3)三種氣體水溶液的折射率都是奈米氣泡尺寸愈小，折射率愈大。(4)三種氣體水溶液的黏滯係數都是奈米氣泡尺寸愈小，黏滯係數愈小，110nm的二氧化碳奈米氣泡使水的黏滯係數降低38.8％。(5)三種氣體水溶液都會阻止甘油在水中的擴散，使其擴散係數變小。

We all do it – walk along with a cup in hand, and carelessly spill it. While it’s usually more annoying than anything else, it happens to affect almost all of us, and little is done to minimise the likelihood of it occurring. So my aim was to explain the physics behind why we spill drinks when we walk, and to investigate how we can minimise the likelihood of this occurring. I broke this investigation into two distinct parts, explaining the system of the cup, and explaining the effect of walking. From initial observations, it was clear that the cup was a resonating system. Like any resonating system, the cup has a natural frequency. When the cup is oscillated – moved back and forth – at near this frequency, the size of the liquid oscillations is very large. This is because the acceleration is in phase with the motion of the liquid, so in each cycle maximum energy is input into the system. In my investigation I experimentally measured this natural frequency, and created a mathematical model to explain this frequency. It was also found that as the size of liquid oscillations in the cup increases, so does distortion of the fluid surface, possibly enabling spilling. To systematically analyse the effect of walking, I had subjects walk on a treadmill, so walking surface and speed were controlled. However, I also needed an accurate way of measuring the motion of a carried cup. Firstly, I tried to use video analysis; however I found this far too imprecise for measuring small changes in velocity of a cup. In the end I used a smartphone to record the acceleration of a carried cup, as acceleration is what causes the movement of liquid in a cup. This allowed surprisingly accurate measurements to be made, and allowed both the size and frequency of the acceleration to be recorded. In order to relate the system of the cup and the oscillation provided whilst walking I conducted a qualitative experiment into the effect of stride frequency on the likelihood of spilling. When stride frequency was very close to the natural frequency of the cup, spilling occurred almost instantly, while it did not occur if stride frequency was much higher or lower. In the end, my research showed that to minimise the likelihood of spilling your drink walk slowly, use a narrow cup, focus on walking smoothly, and fill the cup well below the rim. Despite this, some people happen to be much smoother cup carriers than others, likely due to their individual biomechanics. And, if you really don’t want to spill your drink, you can always use a lid.

本計畫採用數值模擬進行研究，撰寫一維電漿的物理程式來瞭解電漿孤立子在不均勻背景中的演化。我們於去年的計畫中，驗證了這個模型的準確性，這次進一步地在系統中，加入相對論的計算，用以觀察孤立子在相對論作用下的傳播及演化。我們可以觀察到不同參數的初始脈衝會影響到所生成的孤立子形狀，並藉由給予不均勻的背景環境，可以發現孤立子演化的準則。與期刊上發表的論文進行比較時，發現數值吻合，誤差約為1%。因此我們反向藉由論文中的運算式，解出一個孤立子，將其放入系統中，希望藉由這個方式更順利地了解孤立子在空間中的行為模式。未來，我們將利用這些結果來制定多維的電漿體數值模擬，其可以解釋現實宇宙中，蟹狀星雲能源運輸的問題。

本研究主要探討傾角對面轉變的影響與面轉變的原因。當柱體由肥皂水中拉起時，泡膜圖形可分為中央膜平行與垂直底面的形式，兩種形式因高的變化而互相轉換的過程稱為面轉變。三到六角柱傾角越大，面轉變時的高越大，反之亦然；六角柱可以面轉變，且在40°到45°之間有臨界角度存在。本研究以力與能量的角度解釋面轉變．泡膜藉由改變面積以達到最低的能量、維持穩定狀態，因此本研究計算、比較不同形式的泡膜面積，以解釋面轉變。我們同時發現三角錐與四角錐都不會發生面轉換；三角錐的實驗值多大於理論值，四角錐的實驗值則多小於理論值。

1 Purpose of the Research Nanocrystal thin films exhibit many useful properties, including electrochromicity and superconductivity. When synthesised via Molecular Beam Epitaxy (MBE), selection of substrate, specifically knowledge of crystal orientation, is critical. Reflection High Energy Electron Diffraction (RHEED) is an in situ crystal characterisation method highly compatible with MBE. This study explores a new method of RHEED analysis to determine crystal orientation. 2 Procedure/Theoretical Framework RHEED characterization is the incidence of a beam of high-energy electrons at a low angle with respect to the sample surface. Electrons diffract, and interfere to form patterns on the detector. Traditionally, studies of RHEED analyse one static image as a representation of the surface structure, or observations of RHEED patterns over time. The approach to RHEED analysis in this study exploits changes in RHEED patterns given a rotating substrate. Having specific rotational symmetries along different axes, crystal structures can be differentiated by determining rotational symmetry through RHEED. Electrons scatter upon incidence with crystal planes within the crystal to form Kikuchi lines on the RHEED detector (Fig. 2). The orientation of crystal with respect to incident electron beam affects the Kikuchi line patterns. If the crystal is rotated, crystal planes change orientation, and electrons would diffract from crystal planes in different directions. As such, as the crystal is rotated, the Kikuchi lines move. When the degree of rotation of the crystal corresponds to the rotational symmetry of the crystal (Fig. 1), the Kikuchi lines return to their original position. As crystals with different crystal plane orientations exhibit different orders of symmetries, analyzing the Kikuchi line patterns of the crystal at different degrees of rotation can reveal the rotational symmetry and consequently crystal plane orientation of a crystal. 3 Data/Experimental Testing In order to assess the practical viability of the proposed method, experiments were conducted on SrTiO3 (001), (110), and (111). SrTiO3 exists as a typical perovskite structure (Fig. 3), often used in the synthesis of superconductors via MBE. 3.1 Methodology RHEED images of each sample were taken at 0◦, 60◦, 90◦ and 180◦. Curves were fit to each Kikuchi line observed in the image (Fig. 4). These Kikuchi line approximations are compared by superimposing the curves traced and qualitatively assessing the degree of similarity between the Kikuchi lines of 2 images, to verify the order of symmetry and crystal orientation of the crystal. In the images of the superimposed Kikuchi lines illustrated in Fig. 5, there is similarity between the Kikuchi lines when only when the sample has been rotated by an angle corresponding its degree of symmetry. 4 Conclusions This study offers a method to determine the crystal orientation of thin film through determining the degree of rotational symmetry of the sample, by observation of Kikuchi lines in the RHEED pattern as the sample is rotated. Experimental data was analyzed qualitatively to verify the viability of this theoretical method in practice. This method could be extended to analyze the symmetry of other crystal structures. As it does not require information on the machine settings or usage of complex functions to produce a reliable output, this method is fast and straightforward, opening doors to more streamlined RHEED analysis.

本研究的風力發電裝置除了在轉子裝上旋翼外，再將定子裝上另外反轉旋翼，並分析單雙組旋翼在不同電阻、風速等變因下所受的影響，以及磁浮軸承的擺動軌跡。以QBLADE軟體設計旋翼，並以飛機木製作。利用送風機產生風能，以自耦變壓器控制風速、可變電阻改變電阻並進行單雙組旋翼測量；用不同水平力施於磁浮軸承，觀察其擺動。最後將測得數據製成Excel圖表，分析趨勢。

Detection of harmful chemicals used in industrial complexes is crucial in order to create a safer environment for the workers. Presently, most chemical detectors used in workplaces are expensive, inefficient, and cumbersome. In order to address these deficiencies, a novel sensor was fabricated to produce a unique spectroscopic fingerprint for various toxic chemicals. The sensor was fabricated by depositing several layers of silica spheres (diameter ~250 nm) on a glass substrate using evaporation-based self assembly. As the spheres assemble to form a photonic crystal, they also create void (i.e., air) spaces in between them. Once the spheres assemble as a photonic crystal, a spectrometer was used to monitor the reflectivity. The spectrum had a high reflectivity at a specific wavelength, which is governed by the average index of refraction between the spheres and the void spaces. As a foreign chemical infiltrates into the photonic crystal, it occupies the void space, which results in an increase of the average index of refraction of the structure. Consequently, the peak wavelength of the reflectivity spectrum red-shifts, which then confirms the presence of a foreign substance. While the as-grown photonic crystal is able to detect chemicals, it is unable to differentiate between chemicals that have similar indices of refraction, such as ethanol and methanol. In order to detect chemicals with similar indices of refraction, five pieces of a single photonic crystal (i.e. five pixel device) were exposed to different silanes, which changed the surface chemistry of the silica spheres in the photonic crystal. In turn, the five pixel device was able to produce a unique chemical fingerprint for several chemicals, which can be calibrated to detect toxins in the workplace.

熱電材料的條件為導熱差，電導率高的材料，此特性可將熱能轉換成電能，為一新興的再生能源。竹子生長快，為一導熱差的材質，但電導率低。本實驗將野生孟宗竹加工裁切，浸泡於飽和食鹽水加上奈米銦顆粒(73mg/ml)環境中，以高壓蒸氣(121℃、1.1 atm/cm2)處理40分鐘後測量處理前後其電阻變化、增加兩端溫度差及電壓改變的電流密度、增加溫度改變的電流，及熱導率等，並以複式顯微鏡觀察，確認奈米銦顆粒的確有進入竹子維管束內。實驗結果顯示，以飽和食鹽水及奈米銦顆粒高壓蒸氣法處理的竹片，相對於對照組，電導率上升了約1706倍，但熱擴散度只上升了約10%，熱電優值(Thermoelectric Figure of Merit) ZT為 0.059。本實驗方法有效提升竹子的電導率，證實竹子是一個有潛力的新興熱電材料。

Even as a child, I was fascinated by the colors in nature, such as rainbows, butterflies and flowers. This fascination developed into curiosity with age, and as my school studies developed, I became particularly interested in the scientific aspects of the origin and development of colors. I wanted to answer the question: How are the different colors of the butterfly wings related to the nanostructures of scales and pigments? The color on the butterfly wings results either from the pigmentation (chemical color) or from the structure (physical color) of the wing scales. Colors such as yellow, black, red and brown are mainly created by pigments. The interaction of light and structures in and on the surface of butterfly wings, often the size of the wavelength of the light, results in physical colors. These colors are usually bright and dependent on the viewing angle (unlike chemical pigments that spread light diffusely). The colors produced here are usually golden, green, purple and blue. But, where do these colors come from and why do certain species dazzle more than others? To get to the heart of the matter, I identified two key questions: • How are the different colors of the butterfly wings related to the nanostructures of scales and to the pigments? • Using the nanostructure, can you find out the wavelength of the reflected light? In this work, I focus on the structural colors of butterflies and study the physics behind them. This includes parachuting in areas such as diffraction gratings, scattering of light, interference in thin films, and multilayer interference. In order to experience the greatest possible diversity, I selected butterflies from different species for the measurements. Using the spectrometer, I measured the light reflected from butterflies. High-resolution microscopes such as the laser microscope and the scanning electron microscope gave me the opportunity to study the detailed nanostructures of the wing. In addition, I was able to analyze and evaluate my results using existing physical models and MATLAB simulations (Maxwell equations).