全國中小學科展

臺灣

雨水衝擊和土壤滲透速率關係之探討

This research is devoted to researching the influence of rain-drop impact on the rate of infiltration. Rain-drop simulators 160cm tall drip water into a transparent container (14 x 10 x 4) of three kinds of soil (quartz sandstone, loess, sand soil) Through the manipulation of factors such as rain impact (raindrop diameter, raindrop descendent height, frequency of impact) and soil property, we experiment the different possibilities of infiltration and its rate under various conditions. Through this comparison we aim to discover the relation between rain impact and infiltration rate. This research concludes the following: 1. The larger the diameter of the raindrop, the quicker the infiltration rate. 2. The greater the descendent height, the greater the speed of infiltration due to collected descending speed. 3. In the early stage of rain, the greater the frequency of rain impact, the faster the rate of infiltration. 4. Under controlled raining conditions, the larger blank sand soil allows greater infiltration speed. 5. In the later stage of rain impact, a blanket of water accumulates on the surface of the soil, reducing the impact force and thus affecting the rate of infiltration. 本研究試探究雨滴撞擊對土壤入滲速度所造成的影響,針對此問題設計下列方法,以進行探討。我們採用高160cm 的自製雨滴模擬器來滴濺長14cm,寬10cm、高4cm 的透明實驗盒裝入三種土樣(石英砂、黃土與黑砂壤),接著改變各種雨水衝擊因子(不同直徑的水滴、不同的落下高度、不同的撞擊頻率)和土壤條件(土壤性質…)等變因,讓滴濺過程產生不同的情形,滴濺過後再行滲透作用,比較各情況所造成的滲透速率快慢的差異,尋找出雨滴衝擊和土壤滲透速率的關係。本研究有以下幾點結論:1. 雨滴粒徑愈大,對於土壤的入滲速率愈快。2. 雨水落下高度愈大時,因水滴動能的增加,土壤的入滲速率也愈快。3. 在水滴撞擊的初期,當水滴滴落頻率愈大時,土壤的入滲速率也會愈快。4. 當雨滴條件相同時,平均粒度較大的黑砂壤其入滲速率較快。5. 在雨滴撞擊後期,因表層土壤產生的水膜造成雨滴撞擊能量的變化。當水膜厚度愈大時,撞擊產生的能量有減少的趨勢而影響了土壤的入滲速率。

DIY線上製作個人化字型--中文字結構分析與重組

中國文字,這個博大精深的文化,無論是書法中的篆隸楷行草,抑或是現代印刷變化多端的字體,都有其可觀之處。尤為在電腦字體的應用中,近年的發展以來,的確為生活帶來許多色彩;方便的閱讀,生動的海報,甚至是資料的建立,都拜中文字型之賜。為了讓廣大的使用者有更多更個性化的字型選擇,本研究尋找每個中文字在手寫上的特徵,記錄並歸類成「組字元素」,進而建立「學習樣本」以供使用者透過線上的手寫界面輸入,系統再予以分析並模擬組合成更多的字。研究目的在於要如何讓使用者僅提供少數的筆跡資訊,就可輕易的做出一套擁有個人筆跡的字型檔。

界面活性劑對硫奈米微粒形成機制的影響

硫代硫酸鈉在鹽酸中會產生自身氧化還原反應。溶液維持一段時間的澄清透明,突然快速析出硫微粒而顯得白色混濁,同時顯現廷得耳效應。溶液維持勻相的時間稱為延遲時間,其長短隨起始物濃度與溫度而異。在反應溶液中添加界面活性劑可有效增長延遲時間。以UV-Vis光譜儀分析反應溶液的吸收度變化,界面活性劑的濃度夠高時,延遲時間的倒數與添加界面活性劑濃度的倒數成簡單正比關係。此速率定律式符合界面活性劑與硫核微粒結合形成保護核的機制。陽離子性的界面活性劑如CTAB,明顯地較陰離子或中性界面活性劑有較佳的保護效果。IR及X光繞射光譜分析顯示CTAB與硫微粒有共沉澱的現象。The thiosulfate ions undergo disproportionation in hydrochloric acid to form sulfur. The reaction solutions remain clear first, followed with sudden formation of discrete particles that are observed by the appearance of Tyndall beam. The induction periods vary upon the initial concentration of the reactants and temperature. Addition of surfactant to the reaction solutions significantly prolongs the induction period, indicating the association of surfactant molecules with the nuclei of sulfur particles can hinder the aggregation of sulfur particle-nuclei. The UV-visible spectrophotometric measurements for the formation of sulfur particles in the presence of various surfactants show that the reciprocal values of induction period are proportional to the reciprocal of surfactant concentrations. Such a rate law is elucidated by an associative pre-equilibrium mechanism. The surfactant molecules appear to effectively protect the nuclei of sulfur particles from aggregation. The cationic surfactant such as CTAB demonstrates better "protection" ability than do the anionic or neutral surfactants. The IR and X-ray diffraction analysis indicate that CTAB can result in co-precipitation with sulfur, also supporting the suggested mechanism.

光質對植物生長及生理之影響

為觀察不同波長光對植物光合作用要素「葉綠素含量」的影響。實驗材料甘藹(蕹菜種、台農57號、台農64號)組織培養苗。正常光照三週,使其具備基本之根、莖、葉,再移入不同顏色雙層玻璃紙(藍光、綠光、紅光)所構成不同光質之光照環境。除觀察生長狀況外,亦利用分光光度計測定葉綠素a、葉綠素b及兩者總含量。結果顯示藍光和紅光為促進葉綠素合成之主要光譜。藍光組合成的量為對照組的 80.5%;紅光組合成的量為對照組的82.5%。更進一步利用氧氣電極測定光合作用速率。結果顯示以紅光組的光合作用最為旺盛。紅光組光合作用速率為對照組的68%。This is study dealt with how light of different wavelengths make a difference on the content of chlorophyll. The material was tissue-cultured sweet potato(Weng-tsay native variety, Ipomoea batatasL cv. Tainung 57 and Ipomoea batatas L cv. Tainung 64). For first three weeks, we exposed them under normal sunlight so that they would possess basic structure such as root, stem and leaves. Then we moved them into different illumination environments (blue, green and red light) made by double-layered glass plates. Besides inspecting their growth, we also measured the quantity of total chlorophyll and chlorophyll a, b with spectrophotometer, Hitachi U2000. The results indicated that blue and red light was the main spectrum to accelerate the content of chlorophyll. The plant grown in blue environment had content 80.5% chlorophyll of the control group; while 82.5% in red environment. Furthermore, we used oxygen electrode to inspect their rate of photosynthesis. The result showed that the red light treatment highest rate of photosynthesis among treatments, which was 68% of the control group.

音材施教--簡易音高辨識程式

我們製作了一個音準練習程式:使用者輸入聲音後,經由音頻辨識方法求出其頻譜中最高振幅之頻率,以之為音高,再將其與目標音高相較,得到其誤差率及走音程度。此外還可發出對應的鋼琴及正弦波的聲音,方便使用者校音。文中說明音頻辨識的方法,一些關於音樂的基本知識,微軟公司的wave 檔格式,及此系統之應用。我們使用FFT 辨識頻率,且將針對此部分演算法做簡單的說明,並探討如何達到所需之頻率準確度,及如何以較高效率辨識。目前誤差率已可達到1Hz 以下,判斷時間也在秒之內。儘管國內外也有一些具備相似功能之音樂編曲軟體,但其功能十分繁複,使用者常需花費數週時間學習,且價格常高至數千元,非一般使用者所能負荷。而這個程式不但使用方便,功能簡單,容易上手,且不需任何費用。We have developed a singing-practicing program: after input the sound, we judge its pitch from the corresponding spectrum; then we compare it with the selected one, and output the deviation, so that the users can see if they had been out of tune. Also, we provide the sound of the piano and the sine wave sound of the chosen pitch, which can help users get the right pitch. This report will briefly introduce the method of pitch recognition, some basics of music, and Microsoft's wave file format. In addition, we explain the application of this program. We use FFT to transform a sound wave into the spectrum, which are briefly explained in the article, too. Also we’ll discuss how to improve the accuracy and efficiency of the transformation. So far the deviation is less than one Hertz, and the recognition takes less than one second. Though there have been some commercial software with similar functions, they are often complicated to use, and cost a lot. This is not affordable to most users. On the contrary, our program is not only convenient and easy to use, but also has a simple user interface. What’s more, it costs no money!

冷熱生電-熱電效應之席貝克效應(Seebeck effect)

席貝克效應〈Seebeck effect〉是熱能與電能之間的一種固態能量轉換方式,當兩種不同性質的金屬導線之端點連接形成封閉迴路時,若兩接點間有溫差,則兩接點間可測得電壓,而因單位溫差所產生的電壓差稱為席貝克係數〈Seebeck coefficient〉。由本實驗的結果發現:溫差大小、導線特性〈熱電係數〉、導線表面有無氧化層是影響席貝克效應中電壓值及席貝克係數大小的原因。溫差越大,電壓值越大。鉑〈Pt〉與其他金屬的熱電偶導線組合之熱電轉換效能為Pt-Fe > Pt-C > Pt-Al > Pt-Sn;導線的表層若有氧化層,會造成電壓在上升過程中穩定性不佳,產生高低起伏的跳動溫壓曲線,但在較高溫差時,溫壓曲線趨於穩定上升狀態。The Seebeck effect is one of thermoelectric effect. A voltage existed between two ends of different metal wires when a temperature gradient existed between the two junctions. This means the conversion of temperature differences directly into electricity. The voltage induced was called electromotive force, EMF. The EMF generated was dependent on the properties of the wires, which formed the thermocouple and the temperature difference between the junctions. This paper was to study the effect of variety of wire combinations and geomtric properties of wires in thermocouple on the Seebeck coefficient generated. The results indicated that temperature difference, wire properties, and absence or presence of oxidative layer on the surface of wires were the factors to affect the magnitude of voltage and the Seebeck coefficient. As the temperature difference between the junctions was increased, the voltage increased. The combination effiency of conversion of temperature difference into electricity of platinum was following: Pt-Fe > Pt-C > Pt-Al > Pt-Sn. The presence of oxidative layer on the surface of wires caused instability during the process of voltage increase. It made the temperature-voltage curve up and down. On the contrary, when the temperature difference was big, the temperature-voltage curve became increased stably. The temperature-voltage curve was independent of geomtric properties of wires.

聽音辨位的研究及其應用

本研究由電影「十面埋伏」中聽音辨位擊鼓的神技獲得啟發,進而探討聽音辨位的原理,並以一對麥克風同步錄音時所產生的左右聲道接收音訊的時間差,來印證聽音辨位的可行性,運用此原理以一般常見的電腦音效卡與廉價的聲波感測器(壓電式蜂鳴片)來實作,並將其應用在彈著點及時顯示系統上。由實作與測試的結果看來,我們的方法可以正確的判斷出音訊資料中左右聲道的時間差,並即時地顯示出彈著點的位置座標,在48公分見方的靶上,平均誤差是1.18公分,還不錯的成果。

綠色化學實驗-利用溶劑特性回收實驗後的硫酸銅

利用99%丙酮及95%酒精可以把硫酸銅晶體從實驗後的廢棄水溶液中取出來; 如同搾汁機一般,將硫酸銅結晶從水溶液中析出,其析出率可高達95.0%~90.0%。不需要外加能源,只需加入適量體積的丙酮、酒精溶劑靜置24小時不用攪拌,一顆顆漂亮的硫酸銅晶體就析出沉於底部。經過簡單的過濾及烘乾硫酸銅晶體就可以回收再利用,過濾的溶液經過簡易的蒸餾也可以回收丙酮及酒精,留在下次重複使用。如此便能解決化學實驗室硫酸銅廢液的儲存及處理。此種流程也可以用於,部分含有無機化合物的廢棄水溶液。簡易安全的操作,可回收再利用,減低衍生物的產生等,是綠色化學實驗的目標。By the use of 99% pure Acetone and 95% pure Alcohol can take the Copper Sulfate crystal out of the waste solution, as the way that juice press operates to separate the Copper Sulfate crystal from the solution. The rate or the separation can high up to 95.0%~90.0%.Without the need of extra energy, simply add proper mass of solvent like Acetone or Alcohol(refer to Result and Discussion) and place it 24 hours without stirring. Beautiful separated crystal can be recycled and ate capable to use again. By simple distillation, the filtered solution can recycle the added solvent such as Acetone or Alcohol which can also reuse next time. By doing so, the problem of storing and managing the waste solution of Copper Sulfate in laboratories of Chemistry will be solved. This procedure can also be used in parts of the waste solutions which contain inorganics. Simple and Sage operation, the capability of recycling and reusing and reducing derivatives etc., are the goals of Green Chemistry.

FeSO4 催化雙氧水製造氧氣之研究

1894年H.J.H Fenton首先發現亞鐵離子催化過氧化氫具有強氧化力,故將其稱為” Fenton reagent”。在本研究裡將對Fenton做一深入探討,探討在不同 pH值溶液、不同Fe2+濃度比下產生氧氣的效能,並且間接也印證了 HO · 自由基在 Fenton reaction 製氧過程中的重要性。 亞鐵離子在Fenton reation ,並非單純只當催化劑。當 pH =3.0、4.0、5.0時,過氧化氫與硫酸亞鐵濃度比為1:0.25、 1: 0.5 、1:1 時,當 FeSO4濃度增大時,氧氣產量依序增加。依反應機構解釋,可確定亞鐵離子為Fenton reaction 反應速率之重要因子。但,當pH 較高且硫酸亞鐵濃度為過氧化氫兩倍時,反而抑制氣氣的產量。且若當條件為 pH = 5且過氧化氫與硫酸亞鐵濃度比為 l : l 時,氧氣生成平衡體積最接近最大體積,可證實過氧化氫在短時反應最完全。由結論中幾個論點可歸納出,常實驗條件為 pH = 5且過氧化氫與硫酸亞鐵濃度比為 1: 1 時,氧氣的收集會有最好的效果。 In 1894, H. J. Fenton first found that the ferrous iron can catalyze hydrogen peroxide with the strong oxidizing ability; so we called “Fenton’s Reagent”. This discovery will make a further research to explore the efficiency of the production of oxygen that under a series of different pH values, arid different proportions of Fe2+ concentration . This experiment indirectly proves that the free radical of hydroxyl ion as a important role to produce oxygen in the Fenton reaction. In the Fenton reaction, the ferrous iron is not simply utilized as the catalyst. While the pH value is 3 4 and 5, and the proportion of hydrogen peroxide to ferrous sulfate is 1:0.25, 1:0.5, and 1:1, when the concentration of ferrous sulfate increases, the volume of the oxygen produced will increase simultaneously. According to the reaction mechanism, we affirm that the ferrous iron is a significant factor in the Fenton reaction rate. But, if the pH value is higher, and the concentration of ferrous sulfate is the double of hydrogen peroxide, the rOl1jJj1C of oxygen is refrained reversely. And as the pH value is 5, and the proportion of hydrogen peroxide to ferrous sulfate is 1: 1, the equilibrium volume of the oxygen produced will approach the maximum, which proves that hydrogen-peroxide can completely react in a short time. According to the conclusion, we conducted that as the pH value is 5, arid the proportion of hydrogen peroxide to ferrous sulfate is l:1.which is the optimum condition of the oxygen preparation.

彭巴效應之實驗探討

延續38 屆北市科展的研究主題繼續研究,針對實驗方法進行改良。用熱敏電阻、數位電錶、冰箱冷凍庫、不同水溫,測繪「冷卻曲線」探討彭巴效應。發現在80℃、60℃、40℃、20℃的不同水初溫中,初溫愈高的水,完成冷涷的時間愈短。由冷卻曲線觀察,發現初溫較冷的水比熱水有更明顯的過冷現象。由冷卻曲線觀察,彭巴效應非常明顯,並且可由曲線上準確量測結冰始末的時間。彭巴效應明顯,並可重覆實驗。這次的研究探討,有助於我未來在彭巴效應實驗的量測技術。可應用於一般家庭冷卻物品時,快速冷卻,節省時間。可找出結冰的經濟初溫範圍,提供往後各領域利用. Hot water freezes faster than cold water? It is surprising to most people, but it is true. It has been observed and studied in numerous experiments. I tried to set up an experiment to explore the so-called Mpemba effect. I use NTC, multi-meter and house refrigerator to construct cooling curve for water of various initial temperature. The Mpemba effect is discussed based on the cooling curve. I found that the benefit of using NTC is faster measurement, higher sensitivity and cooling process is not disturbed. By inspection of the cooling curve, the Mpemba effect is obvious and repeatable. The initial and final state of freezing process is easily determined. Cold water reveals super-cooling phenomena. Inspection of gas bubbles in freeze ice showed that cold water contains more gas than hot water.