全國中小學科展

臺灣

實驗探討液體表面交叉波的一些性質

交叉波( cross wave )為波峰和振源表面垂直的波,移動方向和振源表面平行,它是以表面張力為恢復力的表面張力波( capillary wave)的一種。

隨機遞迴數列及渾沌現象

給定一個p∈(0,1),令k0=0,p0在(0,1)間隨機分布,定義 k1為能使的最小正整數k,而;相同的,對於給定的kn-1,kn為能使的最小正整數k,。若存在kn使得,則稱p∈In;若對於所有的n與kn,,則稱p∈I∞。如此區間(0,1)可分解成集合I1,I2,…I∞。

棋盤的費伯那契

在學校科研營的教材中,有一個題目,其內容相當於:「在一列格子中 放入黑棋與白棋。白棋不可連續放置,而黑棋不受此限,請問共有幾種可能的排列方式?,在此規則下,若將格子推廣為m列n行的棋盤,那又如何呢?我們對此好奇不已。

以離子溶液催化醇與酸酐的之酯化反應

在酯化反應中,經由實驗結果,我們發現離子液體對於此反應有催化的效果。離子液體 是在室溫下呈現液態的離子化合物,將醇類與酸酐放入離子液體中有助於酯化反應的進行, 基於這個新的發現,我們開始尋找使用不同種類的離子液體做實驗,選出適當的離子液體, 並且測試離子液體在不同環境下的催化效果,以及適合的使用計量;更進一步,我們找出離 子液體在催化反應之後,將離子液體回收的方法:利用有機溶劑將離子液體和產物分層並萃 取出產物,把離子液體回收再利用,符合現代推動綠色化學的趨勢。接下來我們探討離子液 體對催化反應的擴展性與應用,先由不同結構的一級醇反應到醯胺鍵的生成,最後推展到合 成阿斯匹靈,實驗結果說明,用離子液體做催化劑,也可以成功的合成阿斯匹靈。 We have established for the first time that ionic liquids, which possess the property of Lewis acid, can facilitate acylation of alcohols with anhydrides to form esters with photo-excitation. With the initial finding, we then screen through different types of ionic liquids with varying counter anions, loading, and external light or heat sources to sort out the best reaction conditions. To gain insights into the working mechanism, the dynamic profile of the catalytic reaction was monitored by analyzing the reaction mixture by using ‘H NMR spectroscopy. The ionic liquids can be recovered by extractive separation from the acylation product, which meets the major theme of green chemistry. To extend the substrate scope and applications of the new catalytic process, different functional primary alcohols and amines were further examined. More importantly, we have utilized the new catalytic protocol for the acetylating of salicylic acid, leading to aspirin with high efficiency.

含環胺-亞胺雙牙配基及其鎳錯合物的合成、結構鑑定,及烯烴催化聚合反應

本研究合成含環形胺—亞胺雙牙配基鎳金屬催化劑,用以催化烯烴聚合反應。將2-甲基丙醛經由溴化、胺化及亞胺化的步驟合成含胺—亞胺的雙牙配基,Et2NCMe2CH=N(2,6-iPr2C6H3) (3a)、(c-C4H8)N- CMe2CH=NPh (3b)、RNCMe2CH=N(2,6-Me2C6H3) (R = c-C4H8 3c,c-C5H10 3d)。再將配基和Ni(DME)Br2 (DME = 1,2- 二甲烷氧基乙烷) 反應, 形成鎳金屬錯合物Ni [Et2NCMe2CH=N(2,6-iPr2C6H3)]Br2 (4a)、Ni[RNCMe2CH=N (2,6-Me2C6H3)]Br2 (R = c-C4H8 4c,c-C5H10 4d),並作結構鑑定。其中3b、3c、3d、4c、4d 均為合成的新化合物,4d 獲得X 光單晶繞射結構。 以合成之鎳錯合物作為催化劑,催化乙烯或降冰片烯(C7H10)的聚合反應,探討反應活性和高分子產物的性質。與含相同碳數的錯合物比較,在胺基具環形取代基的錯合物對乙烯的催化活性較佳,聚乙烯產物分子量較高,分子量分布範圍狹窄;其對降冰片烯的催化活性略遜於非環形者。同為環形取代基時,六環較五環者對乙烯的催化活性較差,但對降冰片烯的催化活性較佳。顯示乙烯聚合與降冰片烯聚合有不同的反應決定步驟。催化劑及配基的設計的確可以操控聚合反應及其高分子產物的性質。 The synthesis of α-amino aldeimines Et2NCMe2CH=N(2,6-iPr2C6H3) (3a), (c-C4H8)NC Me2CH=NPh (3b), RNCMe2CH=N(2,6-Me2C6H3) (R = c-C4H8 3c,c-C5H10 3d), as well as the nickel complexes Ni [Et2NCMe2C- H=N(2,6-iPr2C6H3)]Br2 (4a), Ni[RNCMe2CH=N (2,6-Me2C6H3)]Br2 (R = c-C4H8 4c,c-C5H10 4d) has been succeeded. Their structures were mainly determi ned by spectroscopy or elemental analysis. The complex 4d was characterized by X-ray crysta llographic analysis. It shows that the nickel complex has distorted tetrahedral configuration. The catalytic reactions of ethylene or norbornene polymerization using the newly synthesized nickel complexes are studied. All catalyts show high activity toward studied olefin polymerization. Comparing the data of the catalytic ethylene polymerization for complex 4c with those of its isomer complex 4a, the former is found to results in higher activity as well as the larger molecular weight of the PE products with the narrower dispersity. On the contrary, 4c shows lower activity in the reactions of norbornene polymerization than 4a. For the cyclic amine derivatives, 4c of five-membered amino group shows better catalytic activity toward ethylene polymerization than 4d of six-membered amino group. But 4d gives better perfomance for norbornene polymerization than 4c. Such results indicate that the processes of ethylene and norbornene polymerization might have different rate-determining steps. These study confirms that the design of ligand and catalyst are crucial with respect to the control of the catalytic olefin polymerization and the properties of the polymeric products.

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.

不完美的完美-探討遞迴數列的圖形分割方法

在 Fibonacci Sequence 中,我將Cassini’s identity 轉換成圖形時發現:邊長為Fibonacci number 的正方形,分割後重新拼成長寬分別為Fibonacci number 前後兩項的矩形,會得到矩形內有縫隙(或重疊)。接著我將Cassini’s identity 的圖形推廣到Catalan’s identity 的圖形,我發現邊長一樣的正方形,拼成的矩形長會變大,寬會變小,矩形內的縫隙(或重疊)面積會以Fibonacci number 平方增長。接下來我再將圖形推廣,邊長為非Fibonacci number 的正方形分割拼成矩形時,我發現若將整數遞迴數列代入Cassini’s identity,圖形將會有規律的方式呈現,且每一種數列的縫隙(或重疊)面積會有所不同;若遞迴數列代入Catalan’s identity,縫隙(或重疊)面積還會再以Fibonacci number 平方增長。所以最後我得到一個通式:只要是遞迴數列[an]的圖形,都會滿足於: 。

淨化我們喝的水-經濟方便的再生過濾器雛型

近年來由於土地過度開發,經常發生土石流,使得自來水廠進水混濁度太高,過濾設施無法正常運作,本實驗裝置可以利用氣昇?和重力作用,來清洗濾層中殘留物物比重較大的雜質,而且濾砂含自動控制昇?還可以重覆使用,如此便能先處理河川中大量的河水。整個過濾器主要分三個部分;(1)下端進水處理處為高比重的雜質重力沉澱處。(2)圓錐狀的濾層以利於自動清洗時砂層的循環。(3)自動清洗監控部分。濾砂清洗的影響因子為濾層厚度的重力、氣昇?壓力含進水量三者交互作用。濾砂以硬度大的石英砂最佳,濾層高度為25cm,平均進水量0.23升/秒,為最佳處理狀態可獲得原水78.5%的乾淨濾液。Debris flow occurs frequently due to the over-development of watershed recently. The water used as the input of water treatment factory is too turbid to be filtered by the traditional facilities. In this study on experimental apparatus was designed to remove the high density particles or suspended impurities. This apparatus can be used as a pretreatment apparatus of filtering factory. There are three main parts in own apparatus: (1) The precipitation one which is the site for precipitating of high specific gravity impurities (2) Cone shape filter layers which allows for cycle cleaning the sand layers (3) The automatic monitoring apparatus. The effet of water flow rate, air pressure, gravity and the height of filter layer on the performance of the experiment were discussed in this study. Experimental results showed that in the study, the height of filter layers is 25 cm, and the average water volume flow rate is 0.23 liter/sec. The apparatus can achieve a 78.5% leaner filtrate from the original water sample.

音材施教-音高與音色辨識之探討

我們使用C++撰寫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能量之頻率,以之為基頻,再將其與目標音高相較,得到誤差率及走音程度。此外程式還可秀出所唱的樂譜,和發出對應的鋼琴或正弦波的聲音,方便使用者校音。而為了做音高辨識,我們也收集了許多聲音檔案,觀察其特色,研究不同音色的頻譜或是波形特性,並利用其特徵完成一個音色自動辨識程式。\r 首先我們測試了各種演算法,並且選用了快速傅利葉轉換作為主要製作的演算方法;接著我們利用Microsoft Visual C++撰寫我們的程式。這個程式主要可分為錄音、辨識以及樂譜繪製三大部分,皆會在此份報告中詳細說明。\r 文中將說明音頻及音色辨識的方法,一些關於音樂的基本知識,微軟公司的wave檔格式,此系統之應用,以及音色的波形頻譜分析。我們使用FFT 求得聲音的頻譜,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,如何以較高效率辨識,及如何找出不同音色的特性。

親愛的,我把汽油”變硬”了!

汽油給人的第一印象想必就是危險易燃,並且很容易揮發,在運輸及保存上有許多缺點,最簡單來說,汽油的高揮發性造成能源的散失、汽油的易燃性則造成了許多意外。而萌生研究製成汽油固態燃料的念頭。