物理

隨著社會漸漸的現代化，我們需要愈來愈多的電力，然而在享用電力時，更伴隨著汗染的到來。所以討論如何有效的利用能源及探討無汗染能源，是本實驗研究的主要課題，以下即是我們的介紹。

本研究主要是探討液晶面板在不同的電壓下，對紅外光區及可見光區之穿透光譜。藉由控制外加液晶面板兩側的電壓，改變內部的電場強度，驅使液晶分子長軸方向改變(偏轉)，以達到控制穿透率之目的。施加於液晶面板兩側的電壓V大於起始電壓V0時，液晶分子長軸受電場作用與電場方向平行，減弱引導偏振光扭轉之能力，讓部分光通過偏振片。令及分別代表穿透率達到最大穿透率之10%及90%時的外加電壓，則定義「光-電開關斜率」γ為：γ =(V90-V10)/V10。透射光強度與外加電壓關係曲線則稱為「光-電開關特性曲線」。穿透率除與液晶分子之旋光程度有關，我們也做了在不同電壓下，液晶分子之穿透光譜，並討論其特性。The main idea of the project is to discuss the transmittance spectra of liquid-crystal device in the range of infrared and visual light (400~900 nm) with different electric field by changing voltage. Different biases are applied to the liquid-crystal cell, causing the axis of liquid-crystal to rotate, and the transmittances are measured. If the application of bias is greater than the threshold voltage (V0), the axis of liquid-crystal will be parallel to the electric field, and make the beam pass through polaroid. Electro-optical switching slope γ is defined as γ =(V90-V10)/V10 , where V10 and V90 are the applied voltages enabling output light signal reaches up to 10% and 90% of its maximum intensity, respectively. It is understood that transmittance depends on the optical activity of liquid-crystal cells. Besides, we will discuss the relation between wavelength and transmittance of liquid-crystal cells.

本研究利用波以耳定律為基礎，以理論計算推導的方式，模擬水氣壓計的操作模式，並 探討其校準模式與誤差來源。 以此設計出的水氣壓計有以下兩個特色： 1. 大氣壓力的變化與水氣壓計液面的變化為線性關係。 2. 可以得到比水銀氣壓計更佳的靈敏度。 而在水氣壓計的校準上分別探討了標準校準、壓力差校準、溫度校準與重力密度校準。 利用標準校準可以得到水氣壓計液面變化與大氣壓力變化的線性關係式。而溫度校準與密度 校準在儀器操作環境為定溫下則可併入標準校準。 This study based on Boyle's law imitates the operation model of water barometer and discusses its calibration and sources of error. The designed water barometer has two features: 1. The relationship between atmospheric pressure and the height changes of the surface of the water barometer is linear. 2. More sensitive than that of a mercury barometer. We also discuss standard calibration, pressure calibration, thermo calibration and gravidensity calibration. The linearity between atmospheric pressure and the height changes of the surface of the water barometer is known by standard calibration; thermo calibration and gravidensity calibration can be merged into standard calibration under constant temperature surroundings.

Light diffraction and interference are two of most basic experiments, but they’re the most powerful evident of wave properties of light. Due to the lack of high-quality and fairly accurate equipment, these important experiments are limited to the simple demonstration of the phenomena. Especially, the spatial intensity variations of diffraction and interference patterns are, however, completely not drawn to scale. In order to precisely measure the diffraction and interference patterns intensity, we consult lots of reference, search for suitable materials and reuse waste old and useless laser printers. Finally, overcoming disadvantages of time consumption and poor spatial resolution, we develop two accurate, practical and delicate methods. We use optical power control circuit created on our own to steady the brightness emitting of laser diode. Then the high linear photoelectric detector is stored on XYZ axis micro movement control platform. Next high degree of reflection rotating polygon mirror employing optical lever is collocated with low vibration blushless motor. Thus, a self-scanning intensity pattern plotter is accomplished. At the same time, it overcome difficulties like time wasting and low reliability during doing these kind of optical experiments. In this article these two dependable and worth popularizing measurements of light diffraction and interference is going to be introduced. 光的繞射與干涉實驗是光學中最基本的實驗之一，也是證明光的波動性質之最主要的依據。在一般的高中物理實驗室中受限於器材的等級與精度，只能對光的繞射與干涉做近似定性的實驗，尤其是繞射、干涉圖形上的光能量分佈，完全無法以現有的器材做精準的測量。 在這一年的專題研究中，我們小組針對測量光的繞射、干涉能量分佈為目標，參閱許多相關文獻，四處尋找適用的材料及零件，發揮廢物利用的精神，克服萬難，發展出兩種精巧、實用又準確的測量方法，我們以自行發展的光功率控制電路使雷射二極體的光度穩定，並且以高線性度的光感測元件裝載在自行設計的X.Y.Z微動機台上，同時利用光槓桿原理所構成的高反射度的旋轉六面鏡，配合低震動的無刷馬達，完成了一套能自動掃瞄繞射能量分佈曲線的測試儀，經實際使用相當地穩定可靠，可以快速而精確地獲得大量的實驗數據，比對這些數據不僅能驗證繞射理論，並能更深入地延伸理論的探討。

在本次實驗中，我們發現溶液中的帶電離子，會因為離子團的熱運動，和電偶極的庫倫吸引力(electric dipole)的交互作用下，使得電解質溶液的I-V curve(電流-電壓 曲線)，具有類似磁滯曲線(Hysteresis curve)的效果，同時我們運用光學干涉的原理，證實此時在電場作用下，離子團會互相順著電場方向作條列鍵結，而加熱實驗也證實，熱運動會使溶液的I-V curve(電流-電壓 曲線)變的不一樣。另一方面，我們也發現，在給予電解質溶液一外加的衝擊電壓時，該溶液的電荷分布，?會因為彼此的互相擠壓以及自由擴散的作用下，而形成一震盪分布，其所顯現出來的，則是電壓的震盪變化。最後由於震盪波紋的變化，在起始時與中段之後有著明顯差異，我們對此變化提出看法和證實，相信內容是精采可期的！ In this experiment, with the interaction of the heating action of ionic atmosphere and electric dipole, we find that ionic in the liquor makes the I-V curve in the electrolyte liquor show up with the effect similar to Hysteresis curve. Meanwhile, we practice the principle of interference to prove that at this moment, under the influence of electric field, ionic atmosphere will connect to each other in line following the direction of the electric field. It is also proven that in the heating experiment, heating action will make I-V curve in the liquor different.On the other hand, we also find with extra electric impact, the charge distribution of the liquor will form a oscillation, that is, the changes of the voltage oscillation under the inter-collision and the free spread. We offer our viewpoints and proofs about the obvious changes of oscillation wave in their beginning stage and after their middle stage. We believe that the marvelous content is surely worth of your expectation.

日光燈是我們最常用的照明設備。傳統的日光燈是屬於電感性的負載，接上電源後其電壓與電流的波形會產生異相位的問題，造成無效功率。本研究是以簡單而且經濟的方法在日光燈的兩端並聯電容器以改善其電流落後電壓的情形，減少無效功率，降低電力的消耗。研究中測量日光燈的等效阻抗，並加以相應的補償電容，從電路實驗中觀察，得到功率修正的結果。Fluorescent lamps shine our lives everywhere. However, traditional fluorescent lamps are inductive loads and produce a phase angle between voltage and current when connected to an alternating power supply, which leads to considerable electricity losses. This project uses parallel capacitors with the fluorescent lamp to compensate the phase difference between current and voltage, and thus reduces power consumption. In the study the impedance of a CFL (Compact Fluorescent Lamp) bulb has been measured and compensated with corresponding capacitance. Finally, the power consumption reduction is verified with experimental results.

本實驗利用「閃光攝影術」，由拍攝桌球碰撞球拍拍面瞬間照片，希望能測量桌球與拍面的接觸時距、摩擦力、恢復係數。近年來，數位相機已經具有單眼相機所有功能，所有攝影參數可記錄調整，並且可以馬上看，作影像處理，大幅降低拍攝費用，若配合高速閃光燈，可以拍到重複曝光照片，所有的數據由照片測量，是計算碰撞問題的新的構想，適用於所有球類的碰撞。

My aim was to test the effectiveness of coolboxes under different\r conditions, to use this information to do comparisons using commercially\r available coolboxes and finally to build an effective and cheaper coolbox\r appropriate to Namibia\r The general method used to compare different coolboxes involved\r measuring the rate at which ice melted inside the cool boxes under\r different conditions.

It is extremely costly to care for elderly people who have suffered a serious fall. Thus, doctors welcome a device or method to identify people prone to falling, to reduce elderly health costs and enable those identified as “fallers” to take precautions. Recently, a Sound Wave Assessment (SWA) device was developed to determine if tested human subjects were prone to falling. It is based on the concept that all humans exhibit postural sway while standing stationarily. The device employs two sonar transducers, which emit and receive ultrasonic pulse signals. The first transducer is positioned on a tripod, while the second is attached to the lower back of the human subject. Each transducer emits ultrasonic modulation pulses, which are detected by the other transducer. The distance between the two transducers is calculated from the time taken for the pulses to travel from the sender to the receiver. Hence, we can measure the small displacement fluctuations of the standing human subject, both approaching and receding from a static transducer, as a function of time.

本研究探討不同的控制變因，對磁性流體薄膜在水平磁場下有序結構的影響。我們發現，外加水平磁場於磁流體薄膜時，會形成一維有序磁鍊排列，磁鍊間距除會隨著磁場增強而變小外，另外其條件值如磁場強度、流體濃度、磁增率、薄膜寬度及厚度等也影響磁鍊間距。其中磁增率及磁流體濃度增加會使磁鍊間距變小，而凹槽寬度及薄膜厚度增加會使磁鍊間距變大等現象。至於其形成磁鍊的物理作用，我們假設薄膜有三種能量交互作用，即(1)磁鍊與外加磁場間的磁能UdH。(2)兩條同方向磁化的磁鍊間相互排斥所造成的磁能Udd。(3)熱能Uther等。藉由系統能量Udh+Udd+Uther最小化，我們導出了磁鍊間距和外加磁場之間理論上的關係，並比較實驗結果確實具有相當的一致性。因這些有序結構會引發許多的光學性質，將來這些特殊的光學性質預料應可製成可調式光柵、光開關及顯示器等光電元件，使磁流體在奈米世界及光電領域裡扮演重要角色。We investigate experimentally the structure of the magnetic chains formed in the magnetic fluid thin film under the influence of the external magnetic field parallel to the film surface. A one-dimensional ordered structure forced by magnetic chains can be obtain in the magnetic fluid film. It is worth noting that the ordered structure can be manipulated by changing the control parameters such as the magnetic field, concentration of magnetic fluid, the thickness of the film, the width of the film, and the dH/dt. On the other hand, the physical mechanism of forming the ordered structure can be also studied theoretically. These magnetic chains are regarded as magnetic dipoles and three possible interactions are condisered for the energy of the system: the attracting potential energy between the magnetic chain and H(denoted by UdH),the repulsive potential energy between two magnetic chains with parallel magnetizations(denoted by Udd), and the thermal energy Uther. The relationship between the chain distance △x and the applied magnetic field H was derived by minimizing the total energy of the system with respect to the chain distance. The experimental data is consistent with the theoretical results.