全國中小學科展

工程學

樂器聲波之探討(The Study of A Sound Wave on Musical Instruments)

演奏樂器時,是使發聲體產生駐波而發出各式各樣悠揚的聲音及音調;樂器主要分成振動體(發聲體)及共鳴器兩部分,依發音方式分為弦樂器(使弦振動產生駐波)、管樂器(利用空氣柱振動產生駐波) 及打擊樂器(利用板、膜或磚等彈性材料的固有頻率振動產生駐波)。聲音有三要素:振幅、頻率及波型,響度取決於振幅大小、音調與頻率有關、波型則由不同的頻率及響度組成。樂音多變的主因是音色及音調。音色是發聲體的發音特性,取決於該發聲體的聲波波型。音調即聲音的高低,與發聲體的振動頻率材質息息相關,頻率愈高,其音調愈高,而樂曲中的音階高低則是由音調高低所構成。樂曲的製作及演奏必涉及到律制,從駐波的產生、律制的探討、頻率的測量和琴鍵的振動模型建立與波形的觀察,我們使用計頻器、示波器及有限元素ANSYS 軟體、數學計算Mathematica 軟體,我們設計一系列實驗,企圖對樂器聲波操作技巧有更進一步的認知。從實地走訪樂器製造廠,了解到設計與改良仍是樂器工藝家重要課題,本文的實驗方法可提供大型演奏會現場調音、樂器調音師或樂器工藝家設計製造樂器時參考用,對於發展文化產業期待提供更經濟與實用的建議。;Playing musical instrument is to make sounding part produce stationary wave so as to give off various gentle sounds and tones. According to different modes of sound producing, musical instruments which comprise vibrator (sounding part) and resonator can be divided into stringed instruments (which vibrate the strings to produce stationary wave), wind instruments (which produce stationary wave with vibration of the air column) and percussion instruments (which produce stationary wave with natural frequency of boards, films or bricks). Three Essentials of sound include amplitude, frequency and waveform, in which the amplitude decides the volume, tones are related to frequency and the waveforms are composed of different frequency and volume. Various musical sounds are mainly due to different timbres and tones. Timbres, sounding characteristics of sounding part, is decided by waveform of the sounding part. Tone means pitch of the sound and is closely related to vibrating frequency of sounding part. Higher frequency makes higher tones and pitch of a musical scale is decided by different tones. Music composing and playing is necessarily connected with music temperament including producing of stationary wave, discussion of temperament, measurement of frequency, establishment of vibrating mode of keys and observation of waveform. We adopted frequency counter, wave inspector, ANSYS software and Mathematica software and designed a series of experiment to get further knowledge of technique of handling musical instrument wave. After visiting musical instrument manufacturers, we learnt that design and improvement are still the essential subjects for instrument craftsmen. Experimental method in his article can provide reference for on-the-spot tuning of large concert, musical instrument tuner and musical instrument designing and manufacturing by craftsmen, and more economic and practical suggestion for cultural industry development.

平面式雙頻天線合成陣列之研究

The feasibility of new design approach for dual-band antenna array using genetic algorithm is demonstrated in this study. In the past year, one dual-band printed-strip dipole antenna, which operates at 0.9/1.8 GHz, had been implemented in the laboratory and leads to a satisfactory performance. However, the antenna element is suitable for application at base-station rather than handset. Conventional antennas suitable for base-station application are arrays, which consist of antenna elements and at least one feed network. Feed networks for antenna arrays are usually designed to operate at single-band capability, and therefore, it requires two feed networks for a conventional dual-band antenna array. Nevertheless, a dual-band antenna array fed by signal feed network is feasible in our study. To begin with, a full-wave solver ID3D is applied to evaluate the impedance matrix of antenna array with eight elements. Then, the antenna array is modeled as a cascaded equivalent transmission line such that the genetic algorithm could network of dual-band antenna array and yields a seven-section design, which meets the specification of base-station antennas.在過去的一年裡,本人曾製作過具有雙頻效果的雙面印刷偶極天線,並得到不錯的量測結果。由於此天線單元於實際應用上適於基地台天線陣列之設計,所以本研究著眼於天線陣列的設計。傳統上天線陣列的結構包含了兩個部分,分別是天線單元以及饋入電路。目前基地台所使用的大多都是單頻天線陣列,在雙頻天線陣列部分,通常需要兩個饋入電路分別對不同頻帶作訊號的饋入;因此,我們希望能實現使用單一饋入電路製成雙頻天線陣列的想法。本研究中,我們利用之前所做出來的天線單元來合成陣列,並希望此陣列在0.9HGz和1.8GHz兩個頻段都能產生良好的共振效果。我們利用電磁模擬軟體IE3D估算具有八個天線單元的天線陣列阻抗陣列後,再將此天線陣列轉換成串接式等效傳輸線電路。借由基因演算法(genetic algorithm)對此電路做最佳化,我們可以求得饋入電路各段傳輸線的尺寸。由此研究發現,我們的方法應用於單一饋入電路之雙頻天線陣列的設計是可行的,而此電路的模擬結果亦符合基地台天線陣列的規格。

倍位元灰度影像產生器

本研究設計一新型的影像投射系統,可將影像顯示的灰度位元加倍,例如,顯示面板只需用4位元,即可顯示8位元的影像;亦能充分利用光路光源,增加光源使用率。此系統使用兩片相同灰度位元的顯示面板,此兩面板所顯示的影像經過灰度的重新處理,且各經由不同光源強度比值的光路合成後,其灰度分佈將可增為原來的平方倍。經模擬與實驗顯示,此種系統很輕易就能獲得預期目標。無論使用穿透式或反射式皆可應用於目前單片液晶面板之投影系統中;未來可望利用網板來表現灰度,應用於紅外線景物投射系統中,作為紅外線影像式尋標器靜態模擬時所需的高強度動態範圍與高解析度之影像產生器。In this study, a novel image generator utilized in a projecting system has been proposed; it can double the bits of gray-level for image display and enhance the efficiency of illumination of lamp in the optical path. With this system, a 4-bit display panel can achieve an 8-bit image display. Two display panels with same gray-level bits is adopted, images on them will be processed, and then go through different path with a proper intensity ratio. The gray level distribution of image displayed which the two images combined afterward, will be the square of that of original one. The results of simulations and experiments have approved to meet the requirements. No matter transmitting or reflective types can be applied to current projecting systems with single LCD panel. It is expected that a halftone-gray-level pattern will be suitable for this system to form an infrared scene projector, and to act as an image generator with high dynamic range and resolution for static simulation of infrared imaging seeker.

IPod Super Dock

多變色膽固醇型液晶面板之研發

多變色膽固醇型液晶面板為利用具雙穩態(Bistable)特性及因螺距不同而反射特定波長的膽固醇型液晶(CLC)。本研究創新作法為二:一、利用固化的方式使膽固醇型液晶螺距大小不同,使變色機制不同於一般電腦液晶面板,所製的液晶面板為以液晶的特性變色。二、將液晶螢幕中控制液晶的IPS 系統、側邊電極應用於液晶白板中。雙層液晶白板上層為混合E7(向列型液晶)+S811(旋光物質)的Bistable CLC,下層為混合RM82、CB15、BL006、I-369 的多變色(Multi-color)CLC 面板。The main purpose of the research plan lies in the application of the CLC. By using the Cholesteric -the bistable and the wavelength due to different pitch sizes- we can make liquid crystal whiteboard. First, by heating and curing, we are able to cause the pitch sizes of CLC to be different. Unlike the commonly used LCD in computers, the features of CLC itself are applied to the color changing mechanism we make. Second, we apply the IPS horizontal electric field and flank electrode to our LCD whiteboard. In making the Multi-color CLC Display, we mix RM82, CB15 and BL006.

氣流式薄膜測厚儀

醫學上的植皮手術成功率受皮膚厚度影響,皮膚愈薄癒合速度愈快,其中以取皮厚度介於0.05mm 到0.1mm 為佳。在實驗量測時,需要經過一連串繁複的薄皮標本製作,再放到光學顯微鏡下測量,這種厚度測量方式不但耗時,又因嚴重損毀皮膚而不精確。由於使用螺旋測微器做接觸式測量會有形變的問題,因此我們想做間接接觸式的測量,所以採用氣體為媒介,做非破壞性檢測膜厚,這對於在皮膚上的施力遠小於螺旋測微器或是接觸式膜厚計。我們設計一套三頭連管線,使用空氣為媒介,儀器運作原理為在管線一端針頭非常靠近被測物時,所流出的氣體會受到被測物阻礙產生反壓使管線內的壓力上升,導致連通於另一管路的氣泡指示計壓出氣泡,當氣泡為最大氣泡時(半球形)視為達到平衡狀態。實驗時先用已知厚度且不變形的蓋玻片來當作被測物,此時可以算出針尖至蓋玻片的實際距離做為參考值。在量測軟性薄膜時,設計上採用兩側雙針頭靠近軟性被測薄膜兩側以達到氣流氣泡平衡,這時使用螺旋測微器讀取兩針尖距離,減去已知參考值的兩倍距離,即可測出未形變的軟物質厚度。本研究開發一套能測量軟性薄膜的厚度裝置,尤其在皮膚厚度測定上,不但不會直接接觸標本造成損毀,並且能夠快速地測量出厚度值,此為本儀器的最大特色。The thickness of skin graft has deterministic influences on the success of graft surgery. Experimental measurements of skin graft thickness involve complicated specimen preparation processes followed by optical microscopic examination, which are time-consuming and may incur inaccuracy due to possible damage. Here we propose a novel method using air as the media to avoid direct contact of the measured object. The physical operation relies on the following principles: When the tip of a needle connecting to a catheter system is placed close to the object to be measured, the air pumped forward from the catheter system becomes impeded by the object. The resulting backflow pressure opposing the air flow causes an increase in air pressure within the catheter and inflates the bubble connected at the other end. Balance at maximal surface tension is attained when the bubble reaches its maximum volume in hemispherical shape. In practice, a two-needle design was used, each approaching simultaneously from each side of the object. A micrometer was then used to read the distance between the two needle tips, from which the film thickness was derived, subtracting the thickness of the air layer pre-calibrated using cover glass with known thickness. The system implemented was capable of measuring thickness on soft thin films with an accuracy of ± 0.001mm. In addition to rapid measurements with high accuracy, since the pressure exerted on the skin graft is much less than in conventional calipers requiring direct contact, our method has the unique non-distorted and non-destructive advantages.

Promoting Metal Adhesion to Electrospun Fibers and olymer Thin Films with Gold Nanoparticles and Sup

As electronics continue to shrink in size, the cost and environmental impact of current methods of production are increasing dramatically. The purpose of this experiment was to lay the groundwork in another potential method of creating nanowires and printed circuit boards. We believe that through the exposure of supercritical CO2, metalized electrospun fibers with gold nanoparticles will have increased conductivity. In addition, the adhesion of metal to polymer thin films can be controlled with a poly (ethylene oxide) (PEO) mask on both silicon and Kapton substrates. This study found that a specific concentration of gold nanoparticles can make a solution of poly (methyl methacrylate) (PMMA) in chloroform that cannot be electrospun, spinnable. Scanning electron microscopy also confirmed that scCO2 smoothes the surface of the fibers and makes them more uniform. EDX analysis also found that exposure to scCO2 also removed all residues of solvent and cross.sectional transmission electron microscopy showed that the nanoparticles were conglomerated near the surface. In conclusion, scCO2 and gold nanoparticles respectively enhanced the morphology of the fibers and made the electrospinning process more robust. Cross.sectional analysis also showed that the nanoparticles attracted the deposited gold into the fiber making prongs reach from the deposition into the fiber, but there was no test to quantify the adbesion. Using the spray bottle test, the gold still remained on wires. The resistivity of the micro wires was extremely close to that of gold creating resistances within hundreds of ohms over hundreds of micrometers of wires. Thin Films masked with PEO were exposed to scCO2 and metalized with gold or copper. Atomic force microscopy analysis shows unique crystallization formations of poly (capro lactone) (PCL) after scCO2 exposure. ASTM standard peel tests determined that the process was successful with PCL thin films. On the Kapton samples, peeling patterns reversed when the thickness became too great to melt in scCO2.+ Through perfecting these processes, the electronics industry can continue in its miniaturization while the environmental and monetary costs.

這裡真安靜-隔音材質的探討

本實驗針對隔音材質的特性,如各孔板之孔徑、開孔率,並以夾層做不同孔板配置進行研究。本主題共進行三階段的實驗。第一階段探討不同材質的影響,因材質加工問題,實驗誤差過大;第二階段改以PP 塑膠板探討,因儀器誤差,數據難以解析;第三階段仍以PP 塑膠板探討,並修正實驗步驟,以降低實驗誤差。本報告乃以第三階段實驗結果做探討。為了提高實驗準確度,將整個實驗分成若干組,在實驗前後以空白測試,以減低實驗誤差。利用Excel 軟體,進行各組實驗數據噪音傳送損失之修正與分析。本試驗以125Hz、250Hz、500Hz、1000Hz、2000Hz 及4000Hz 六段週波頻率做測試。由分析結果顯示,孔徑與開孔率、同心圓的排列方式,對噪音傳送損失有顯著的影響。;This experiment is to focus on the properties of sound barriers, such as hole diameter, open areas, and the layout of holing boards. We have performed experiments in three steps. In the first step, we discussed the differences between different kinds of material but found many errors caused from faults in the process of making boards. So in the second step, we chose the ploy-propene board but still found errors from instruments. And in the final step, we used the ploy-propene board again and modified the experiment procedure to lower the error from instruments. The report is based on the final step data. With a view to raise the precision of the experiment, we divided the experiment into several parts with the blank test. We modified and transferred the original data to the noisy transfer loss (TL) in the same intensity level, and analyzed the data with Microsoft Excel. In experiment, we detected the noise-pollution level (dB) in the frequency of 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz and 4000Hz. According to the result, the hole diameter, open area and the layout of concentric circle have a significant influence on TL.

Mobile Phone Detector

電蚊拍挑戰A!

本研究以碳化矽(SiC)奈米粉末加入去離子水中,插入銅電極加以電壓進行其表面帶電性的研究。研究中發現SiC奈米粉末的表面帶有負電荷,且加以電壓後,SiC奈米粉末會沉澱下來。利用場發射掃描式電子顯微鏡(SEM)及X-光繞射儀(X-RD)檢測其性質,發現加以電壓使奈米粉末失去電荷而聚集沉澱。同時經由製作不同酸鹼度SiC奈米粉末溶液的陽極極化曲線發現pH值越大,SiC奈米粉末表面電位越高,開放電路電位越小。本研究實驗過程中發現pH值2之SiC奈米粉末溶液加過電壓後,正極生成一透明薄膜狀物質,極有可能是導電鍍膜,應用價值極高。本研究已先進行微硬度試驗與金相實驗,將由長庚大學機械系研究所進行更深入檢測與研究。The electrochemical behavior of the SiC-nanopowder in deionized water was studied. The electrochemical cell was composed of two pure copper electrodes, across which different voltages were applied. The morphology of the nanopowders or even with reacted products was examined using field emission electron microscope(FESEM) and the corresponding phases were identified with X-ray diffraction method(XRD). The experimental results show that tha nano-powders precipitated at the surface of the anodic copper electrode and in the same time the nanopowders in the solution aggregated when 20 volts were applied across two electrodes. That is, net negative charge could be induced around the nanopowder. Deposition rate of the aggregated powders in the various pH-value solutions was evaluated and the aggregated powders were examined with FESEM. The higher Zeta potential of the SiC-nanopowder was examined as the nanopowders immersed in the higher pH value solution. The nanopowders aggregated themselves as the pH value under 2. The anodic polarization behavior of the copper electrode in SiC- nanopowder solution was measured and the results were compared with the aforementioned tests.