全國中小學科展

四等獎

熱處理對水果抗氧化的影響

本實驗是針對聖女蕃茄、櫻桃、火龍果、加州李子、奇異果與恐龍蛋等六種水果以水煮、油浴、微波、微波加油等四種方式來處理,求出水果的抗氧化活性與處理時間的關係,並且利用Arnao研究的ABTS/H2O2/HRP分析系統,以不同濃度的維生素C與延遲時間畫圖作為標準曲線來測量本實驗總抗氧化力效果。\r 由本實驗結果可以了解不論熱處理方式為何,其對六種水果之抗氧化活性初期有增加趨勢,其中以加州李子,火龍果與奇異果尤其明顯,但隨著時間增長則抗氧化活降低。為得到較佳抗氧化效果,火龍果與櫻桃宜用微波處理而奇異果與聖女蕃茄則用油浴較佳,恐龍蛋用水煮方式較適宜,加州李子則適用任何熱處理方式。 \r This research has examined the antioxidant activities of six knids of fruits under\r four diffetent ways of cooking.The fruits being tested include tomato,cherry,Hyloceeus\r polyrhizus,plum,kiwi and peach and the ways of cooking include boiled in water,fried\r in oil,microwaved and microwaved in oil.The antioxidant activites of the cooked\r fruits were evaluated by the ABTS/H2O2/HRP method developed by Arnao and they were\r compared to the antioxidant activities of vitamin C.\r \r The result showed that the antioxidant activities of six kinds of fruits under four\r different ways of cooking were initially increased with heating but they were slowly\r decreased with longer time of heating.Among those fruits tested,the antioxidant\r activities were significantly increased in plum,Hyloceeus polyrhizus,and Kiwi.To\r improve antixoidant activities of fruits by cooking,Hyloceeus polyrhizus and cherry\r is better be microwaved,kiwi and tomato is better be fried,and peach is better be\r boiled. \r

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.

不對稱之美---大葉桃花心木種子飛行軌跡的分析

大葉桃花心木的種子是單翅種子,經測試發現它的結構有降低終端速度及飄移過程具方向性提高種子分佈間距的特性,研究結果顯示: 1.飛行軌跡可分成五個時期:自由落體期、減速期、緩飛期、加速期及終端速度期。 2.種子旋轉飛行軌跡的前進比(advance ratio)屬於推進效率

畢氏定理演繹的正三角形分割研究

畢氏定理(a²+b²=c²)歷經25世紀,發現了數百種的幾何論證法;而畢氏定理演繹出的正三角形 ( (/4) a²+(/4) b²=(/4) c² )幾何分割研究,卻一直沒有人研究。因此,承襲著之前處理幾何問題的經驗,決定挑戰畢氏定理演譯的正三角形分割研究。本文研究兩正三角形,經切割後拼成另一大正三角形;期間以GSP及AutoCAD繪製分析幾何圖形,並建立了4種分割模式,得到了3段式「最佳分割模式」及準「通用分割模式」,提供這方面問題一個可應用於所有條件之完善解決方案。本研究成果豐碩,補足了相關領域的空檔,且可製成益智又富挑戰性之拼圖系列,不管用做教具或遊戲,對建立意至己和相關資料有莫大貢獻! Twenty five centuries after its discovery, hundreds of proofs have been given for the Pythagorean Theorem (a²+b²=c²). But, research about regular triangle dissection extending from Pythagorean Theorem has always been lacking. So, based on previous experience with geometric dissection problems, I have decided to do a research on regular triangle dissection extending from Pythagorean theorem. This research dissects two regular triangles and assembles them into a large regular triangle. Using GSP and AutoCAD to draw and analyze geometric shapes, four dissection models and nine dissection methods are constructed. The extreme values under all conditions are also discussed, as are the best and generic dissection models. There is a Three-section type “best dissection model” and a semi “generic dissection model.” offering a perfect solution to this kind of problem that can be used under all conditions. This study yields numerous results as well as filling in blanks in similar fields. It can also be made into challenging jigsaw puzzles for educational or entertainment purposes.

銅影響大豆及田菁根部生長、細胞死亡和訊息傳遞

隨著迅速的工業化,重金屬汙染已是嚴重的環境問題。在植物中,當植物體內累積過量的重金屬,對於植物根部、葉部等器官的生長與發育有嚴重的影響或傷害。銅離子為植物生長所必須之重金屬,但是過量銅離子會導致細胞死亡,生長受到抑制。本實驗以大豆( Glycine max )及田菁( Sesbania roxburghii )為植物材料,藉由Evans blue 染色法、螢光染色、西方墨點法、反轉錄聚合?鏈鎖反應等,觀察過量銅離子影響植物根部生長、細胞死亡和細胞訊息傳遞物質變化之情形,並探討過量銅離子影響大豆根部細胞死亡的訊息傳遞路徑。過量銅離子會限制植物根部的生長及造成根部細胞死亡。以螢光染色觀察根尖(ROS, reactive oxygen species)、Ca2+累積情形,根尖細胞Ca2+、ROS 累積隨處理銅濃度的增加而上升,可能影響細胞死亡程度。以Ca2+螯合劑EGTA 和W-7(CDPK(calcium-dependent protein kinase)、Calmodulin 抑制劑)前處理發現可以降低過量銅離子對大豆根部的細胞死亡程度,推測Ca2+、CDPK 參與銅引發大豆根部細胞死亡的途徑。為檢驗MAPK 參與根部細胞死亡的途徑,以西方墨點法偵測根部細胞MAPK 的TEY 或TDY 磷酸化,實驗結果發現,隨著過量銅離子濃度的升高,田菁、大豆根部42-kDa MAPK磷酸化情形有上升之趨勢。以RT-PCR 分析大豆MAPK1 及MAPK2 基因之表現量,發現在銅處理時大豆之MAPK1 和MAPK2 基因的轉錄情形增加。大豆( Glycine max )及田菁( Sesbania roxburghii )皆屬於豆科植物,可作為綠肥植物。探討銅影響大豆、田菁細胞死亡之訊息傳遞路徑,希望進而控制生物體所受的毒害情形及訊息傳遞途徑,加強生物體對重金屬的防禦機制,未來可以以基因轉殖等基因工程技術,轉入抗重金屬基因或增強植物體對抗重金屬的能力等,作為綠肥植物、抗重金屬植物吸 附重金屬來復育土地達綠色淨化等用途。 Many heavy metals are necessary for plants, but excessive quantities directly affect plant growth and survival of organisms, cause cell death, or even affect human life indirectly. Cu (copper ion) is a heavy metal, which is one of micronutrients essential for normal growth and development of plants. The purpose of this experiment is to study the effect of excessive copper on Glycine max and Sesbania roxburghii root tips. I conducted some experiments by means of Evans blue staining (analysis of cell death), western blot analyses, and fluorescence microscope in order to examine the way copper results in plant death. Measurement of root length and analysis of cell death showed that excessive copper could bring about the inhibition of plant growth as well as cell death. With fluorescence microscope, I found that excessive copper might increase the level of copper-caused reactive oxygen species (ROS) in both the root tips of Glycine max and Sesbania roxburghii. In addition, I used Oregon Green 488 BAPTA-1 so as to assess the accumulation of calcium ions in root tips and found that the exposure of root tips to excessive copper results in the accumulation of calcium ions. To investigate whether calcium ions and calcium-dependent protein kinase (CDPK) play a role in the cell death caused by excessive copper, I tested W-7, calmodulin and CDPK inhibitors, and EGTA, Ca2+ chelating agents, before copper treatment – immersing copper in CuCl2. In this way, plant cells would be effectively prevented from copper-caused death. Besides, to find out whether copper activates MAPKs in plant cells, I took advantage of western blot analysis with Phosphor-Map kinase Antibody and Map kinase Antibody. The results revealed that excessive copper might lead to TEY or TDY motif phosphorylation of approximate 42- and 64-kDa MAPKs in the cells of Glycine max root-tip and approximate 42-kDa MAPKs in the cells of Sesbania roxburghii root-tip. Furthermore, with RT-PCR, I found that the transcription of Glycine max MAPK1 and MAPK2 mRNA happens more frequently in root cells after copper treatment. In addition, this study suggested that the MAPK cascade CDPK pathway may function in the heavy-metal-signaling pathway in plant, and that calcium ions and ROS might get involved in the copper-caused death of plant cells. By studying signal transduction against heavy-metal toxicity in the plants, we can know how the organisms protect themselves. Sesbania roxburghiivv (or Glycine max), as green manure, could be used for metal-hyper-accumulator with the help of genetic engineering in the future.

薑黃素的特性及其在生活上之應用研究

本研究在探討薑黃、南薑、野薑及一般薑等所含薑黃素的抑菌與抗氧化作用特性,及其在生活及教學上之應用。研究發現:(1)抑菌能力排序:以薑黃最強;一般薑次之;南薑、野薑微弱。(2)抗氧化作用仍以薑黃最為明顯,其餘不顯著。(3)在生活上之應用方面,薑黃素用於檢測水質及食品中是否含硼砂,可明確檢出含硼量;薑黃素所含的天然色素,可用於布料之染色及食品用色素添加劑,亦可用於製造薑黃手工皂,對人體皮膚有益處。(4)在化學實驗上,薑黃素製成薑黃試劑,可做為酸鹼指示劑,另可檢驗一般居家物質之酸鹼性。由以上實驗結果可知薑黃素應用甚為廣泛且深具利用價值。

Vitamin E 對回鍋油品質的影響

家庭中為了節省油量的使用,常將所剩的油品另存於容器中,以待下次使用。近年來,已有不少文獻報告指出,這種「回鍋」的使用方式,往往使得油品品質變得相當低劣。近來市面上有不少的油品,標榜添加天然維生素E,使消費者趨之若鶩,作為一種吸引消費的手段;這激發了我們極高的興趣,因為在文獻中已知道維生素E在室溫下確實可抑制油品的氧化;但添加的油品經過回鍋後,其對油品的影響卻仍不得而知。我們利用鐵鍋油炸澱粉食物,並經由反覆的油炸與冷卻,模擬更真實的回鍋情形。並添加抗氧化劑,包括維生素E和酯化的維生素E,以及回鍋次數等不同的變因進行實驗,進行油品品質的化學變化的測量。經由實驗結果顯示,經數次的回鍋烹煮,油品品質因為一連串的化學反應變得十分低劣;另外,添加酯化的維生素E的油品在某些方面的確減少了某些不良生成物的形成(如游離脂肪酸、羰基化合物等),但在某些方面如氧化程度的比較(共軛雙鍵的生成)卻與一般無添加的回鍋油無異。反倒是添加維生素E對於回鍋油品質的影響在實驗結果的每方面看來,不管是酸敗氧化或是裂解成羰基化合物都能夠有效地減少或產生抑制的作用;故添加維生素E對於回鍋油的品質的確有正面性的影響!Cooking oil is often reused in homes in order to economize on its use. In the past few years, many reports have pointed out that ”reusing” oil this way always changes the properties of oil and makes it spoiled. Also in the past few years, many oil products have appeared on market that highlight the fact that vitamin E has been added, in order to attract consumers. This attracted our interest, since we know that on the basis of several studies, vitamin E indeed has an antioxidizing effect at room temperature or below. However, it is not know what effect vitamin E has on re-cooked oil. Therefore, in this experiment we simulated the re-cooking process by frying steamed dumplings in an iron wok with soybean oil, and repeatedly cooling and re-using the oil. Variable factors were the added antioxidants(vitamin E and vitamin E acetate) and the number of re-cooking times. The chemical variation in the resulting oil was tested with regard to acid value, viscosity, carbonyl value, and the value of conjugated bonds. The results indicated that as the number of re-cooking times increased, the quality of the oil had undergone a series of chemical reactions and became spoiled. Also, the addition of vitamin E and vitamin E acetate indeed reduced the formation of certain unhealthful products such as free fatty acids, carbonyl groups, and so on. In certain respects, such as the quantity of oxidized components in the oil, there is no obvious difference between ordinary oil and oil with the vitamin E acetate additives. However, the addition of vitamin E to cooking oil, based on the results of this experiment, can effectively reduce or suppress processes causing rancidity and breakdown into carbonyl groups. Therefore, the addition of vitamin E or vitamin E acetate dose have a positive effect on re-cooked oil.

微波加速轉酯化生成生質柴油實驗與結果分析

因國際原油價格上漲,因此對研究及發展具潛力的生質柴油引起高度興趣。傳統以加熱方式在適當觸媒下將低碳數醇類與油脂轉酯化生成生質柴油。但以強鹼為觸媒使用過量會讓部分反應轉為皂化。而利用微波,使微波腔在極短的時間內產生電場,使具有電偶極的分子朝向電場方向迅速排列而產生轉動,快速地增加分子間的碰撞頻率而加速反應,但不破壞分子結構。也嘗試利用超音波來生產生質柴油。試驗方法為利用SD-22 柴油引擎測試所生產的生質柴油,並收集廢氣檢驗,評估其污染性。實驗後發現,微波能將一般加熱所需的60 分鐘大幅縮短至4 分鐘,甲醇溶液能生產較多的生質柴油。其中1.40%氫氧化鉀甲醇溶液且油與醇莫耳比1:9 效果較佳。氫氧化鉀甲醇溶液0.80%且油與醇莫耳比1:5 效果亦佳。製成的生質柴油能讓引擎發動,廢氣處理後經分光光度計檢驗氮氧化物,生質柴油確實能有效減少氮氧化物污染。 Due to the fact that the price of international crude oil raises , people look for alternative energy resources actively. Therefore, I have great interests in doing researching and developing the biodiesel through many ways. The traditional way is to transesterify the low carbon alcohols and fats with the suitable catalysts by means of generally heating. However, the overuse of strong bases as catalysts may turn the experiment result into saponification reaction. This study made good use of the microwave to generate electric fields in the microwave cavity in an extremely short time. Owing to the effect electric fields exerted, the molecules with electric dipole momentum rearranged to rotate rapidly .Consequently, the frequency of collision among the molecules increased without destroying the molecule structures. Also, I applied SD-22 diesel engine to test the produced biodiesel and examined the collected exhaust to evaluate its pollutant. According to the results of these experiments, the conclusion was as following: the microwave could shorten the Transesterification reaction time from 60 minutes to 4 minutes. The methanol solution could produce more biodiesel than the ethanol solution. Besides, the 1.40 wt % Potassium hydroxide solution with the molar ratio of oil and methanol 1:9 had the best efficiency in producing biodiesel. On the other hand , the 0.80 wt % Sodium hydroxide solution with the molar ratio of oil and methanol 1:5 also had the great efficiency. All the biodiesel we produced enabled the diesel engine to run smoothly. The exhaust inspected from the examination of Spectrophotometer resulted that the biodiesel did less NOx pollution to the environment indeed.

約瑟夫數列(Josephus Series)

所謂約瑟夫數列,就是有n 個數排成一環狀,從頭開始,殺1(個數)留1(個數),求倒數第k 個留下的數會是多少?約瑟夫數列在台灣的全國中小學科學展覽出現多次(如下表)。全國科學展覽與本題類似的作品 資訊界演算法大師Donlad E. Knuth 在其著作The Art of Programing,CONCRETE MATHEMATICS,也針對該數列作詳細的說明。唯,不論是歷屆科學展覽或是大師的著作,對於該數列,都只是談及殺1 留β或是殺α留1。 筆者則在2005 年暑假,曾經提交於全國國小組比賽作品「老師無法解決的難題」討論到n 個人排成一圈經過殺α留β,最後留下來的情形。 本研究是將α、β、k 和n 作為變數,求:當有n 個數排成一環狀,從頭開始,殺α(個數) 留β(個數),則倒數第k 個留下的數會是多少? 需符合α、β、k、n 皆∈N,且n≧k 1.直觀觀察:發現在每一個循環中,當n 等差α時,Aα,β,n,k 則等差α+β、n- Aα,β,n,k 則等差β。 2.分類:將其分類為cα,n,使當中有規律可求。 3.循環觀察:發現每個循環的尾數n- Aα,β,n,k 都小於β。 4.循環尾數:設計公式求出每個循環節的尾數n、留下數Aα,β,n,k 及n-Aα,β,n,k 。 5.倒推:由與循環節中有等差的性質,則可以由循環節的尾數,推論出循環節中的任意一數。 Joseph Sequence is the problem that discussed the situation of eliminating1 and retaining1 in the circle formed by n people. Joseph Sequence has appeared a number of times in National Elementary School and Middle School Science Fair in Taiwan (as shown in the table below). Past national science fairs and researches on Joseph Sequence The publications,The Art of Programing,CONCRETE MATHEMATICS ,by the expert of mathematical calculation in the IT industry,Donlad E. Knuth,has provided detailed explanation on it. However, all of those only discussed eliminating 1 and retaining β or eliminating α and retaining 1. The researcher proposed “Problems unsolved by teachers” in the national competition, and discussed the situation of eliminating α and retaining β in the circle formed by n people. This study continued the summer project of 2005, and conducted research on the question of when is the last kth person eliminated in a circle formed by n people. In the paper, α, β, n and k were independent variables and the research process was as follows: 1. Direct observation: the series shows equal difference in each cycle. 2. Classification: to search the pattern of the series based on cα,n classification. 3. Use the end number of each cycle to obtain the pattern. 4. Reverse induction: use the equal difference of each cycle to induce when the kth person would be eliminated.

1/2秒的偏移-棒球之變化球軌跡模式的建立

本實驗用了業務用排風扇,並加上整流段,使氣流更加平穩、集中。裝上自製調速器以控制風速,並且改良出微型風速計,以測試棒球上下的氣流流速。棒球部分,則利用家裡面常會用到的圓形保鮮盒,改裝成測試架。此測試架可同時測到水平力、垂直力及阻力,不儘大大地突破過去的測試限制,更可以任意改變旋轉的角度及轉速,以及不同的旋轉軌跡。如此,幾乎所有的變化球都可以模擬出來,也可藉此找出新種的變化球。為了分析打擊時機,我們利用了電腦軟體(威力導演),將打者的打擊影片進行連續的分析,以求得球路判斷點,最後利用電腦做0.01秒為間隔的力量分段分析,使數據更加精確,更有助於棒球軌跡的完整呈現。最後,再透過升力係數、阻力係數和自旋比的關係圖,發現高轉速下與馬格努斯經驗公式相違背的部分。