全國中小學科展

一等獎

東沙島海灘的變遷與復育:由龍擺尾停擺說起

政府最近公佈在東沙群島設立第一個國家海洋公園,顯示國人重視海洋資源的保育與復育;但是東沙島特殊的自然景觀「會擺動的沙嘴」—龍擺尾,卻因興建八座消波塊構築的突堤而消散停擺。本研究以一個高中生的觀點,設計及進行一系列的模型實驗,探討東沙島的形成機制、各種環境因素對海灘及龍擺尾的演化、驗證龍擺尾的現況及如何讓龍擺尾復活,再由東沙島海灘復育看世界的海岸問題。雖然設備很克難,但都能完成預定的目標,證實東沙島的海灘演化。希望此次對東沙島海灘的研究成果與初步探討,能應用於世界上遭受侵蝕而需復育的海岸。In 2007, our government proclaimed Dongsha archipelago as the first national marine park, signifying her emphasis on the conservation and restoration of marine resources. However, the sand spit on Dongsha island, a unique natural wonder commonly referred to as the “swaying dragon tail”, has become motionless since the construction of a total of eight groins along its SE and NE coast during the period between 1993 and 1996. This study has conducted a series of model experiments to verify several fundamental issues, ranging from the formation and the factors affecting the stability and the status quo of Dongsha island and its spit. The experimental results find several favorably outcomes, giving the coast evolving evidences of Dongsha island. Furthermore, strategy to stabilize the coast and revitalize the spit are then considered, which could hopefully benefit the coast suffering erosion on the world’s coastline.

耐熱性酵素生產菌Bacillus Subtilis WLA12 之分離與定性

本實驗針對一取自台北縣烏來南勢溪下游之溫泉菌,進行微生物學、生物化學、分子生物學三方面之觀察與實驗,期能得到一可生產特定酵素之菌種,且具耐高溫之抗逆境能力。對其酵素進行定性,並嘗試轉殖出相關基因,使之可大量表現。目前已篩選出一種可生產多種酵素之菌種〔依其採集地點暫稱WL-A12〕經菌種鑑定為Bacillus subtilis WL-A12。藉由菌落檢測法以及Zymogram 的方式做酵素分析,並以電導轉形等技術,希望能成功轉至E. coli 上表現。另外,也對該菌種作了一些基本微生物方面的觀察〔如需氧情況、最適生長溫度〕。We isolated enzyme-producing thermophilic bacteria from hot springs near downriver of Nan-shi, Wulai, Taipei (北縣烏來南勢溪). Through microbiological, biochemistry and molecular biological analyses, a multiple enzyme-producing Bacillus subtilis strain, designated WLA12, has been isolated. The growth condition of WLA12 was observed. Using basic colony assay and zymogram analysis (gel electrophoresis) to observe the expressed enzymes, molecular weight and gene size of the enzymes were revealed. With comparison to E. coli control strain, the related enzymes were only found in WLA12. To express the Bacillus genes in E. coli, molecular cloning and gene transformation via electroporation was carried out.

應用吸水高分子螯合重金屬離子及奈米銀的製備

聚丙烯酸是尿布中吸水成份,若被隨地丟棄勢必對環境造成污染。分析其結構,由於存在對重金屬離子具螯合作用的羧基,因此,可用於捕捉重金屬離子,作為偵測污水離子的利器。另外,若將螯合的銀離子以化學還原法製成奈米銀,將可應用於抗菌。研究結果有: \r (1)PAA對Mn、Fe、Co、Ni、Cu、Zn、Ag等離子具有明顯螯合效果。 \r (2)螯合反應:PAA+Mn+ [PAA-M]n-x+xH+,其可利用濃鹽酸使其再生。 \r (3)螯合能力以Fe3+最強,Zn2+(Mn2+)較弱。 \r (4)螯合離子的最小極限為10-3(M),我們採樣的廢水有重金屬污染,推測濃度大於10-3(M)。 \r (5)成功將螯合的Ag+製成奈米銀,為金黃色,屬於球形銀,甲醛濃度愈高,奈米粒徑愈小。 \r (6)奈米銀與銀離子在抗菌上的確有明顯效果,帄均粒徑小,抗菌效果越強。

遞迥數列及渾沌現象

給定一個P∈(0,1),令k0=0, p0=p,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n 與kn ,,則稱p∈ I∞。如此區間(0,1)可分解成集合I1,I2,…,I∞。

移動棋子問題的致勝策略

We consider a game played with chips on a strip of squares. The squares are labeled, left to right, with 1, 2, 3, . . ., and there are k chips initially placed on distinct squares. Two players take turns to move one of these chips to the next empty square to its left. In this project, we study four different games according to the following \r rules: Game A: the player who places a chip on square 1 wins;Game B: the player who places a chip on square 1 loses;Game C: the player who finishes up with chips on 12 . . . k wins;Game D: the player who finishes up with chips on 12 . . . k loses. After studying the cases k = 3, 4,5 and 6 for Game A and the relation among these four games, we are led to discover the winning strategy of each game for any positive integer k. The strategies of Games A, B and C are closely related through a forward or backward shifting in position. We also found that such strategies are similar to the type of Nim game that awards the player taking the last chip. Game D is totally different from the rest. To solve this game, we investigate the Nim game that declares the player taking the last chips loser. Amazingly, the strategies of two Nim games can be concisely linked by two equations. Through these two Nim games, we not only find the winning strategy of Game D but also the precise relation between Game D and all others.\r 去年我研究一個遊戲:有一列n個的方格中,從左至右依序編號為1,2,3,....n。在X1個、第X2個、第X3個格子中各放置一個棋子。甲乙二個人按照下列規則輪流移動棋子:\r 一、甲乙兩個人每次只能動一個棋子(三個棋子中任選一個)。遊戲開始由甲先移動動棋子。二、甲乙兩個人每次移動某一個棋子時,只能將這個棋子移至左邊最近的空格(若前面連續有P個棋時可以跳過前面的P個棋子而且只能跳一次),而且每個方格中最多只能放一個棋子。\r 研究這個遊戲問題時,我討論四種不同"輸贏結果"的規定:甲乙兩個人中,A誰先將三個棋子中任意一個棋子移到第一個方格,誰就是贏家。B誰先將三個棋子中任意一個棋子移到第一個方格,誰就是輸家。C誰先不能再移動任何棋子,誰就是輸家。D誰先不能再移動任何棋子,誰就是贏家。\r 當"輸贏結果"的規定採用ABCD時─我們稱為遊戲ABCD。今年我將把這個遊戲問題中棋子的個數由三個推廣到一般K個情形之後,再繼續研究遊戲的致勝策略,同時也將研究遊戲ABCD之間的關係。

誰能比我更善變???~ 釩鎵磷酸鹽的合成及其結構鑑定

This research tries to find out how changes of weight or proportion of a reactor would affect the type and structure of a crystal. In the experiment, the Hydrothermal reaction was adopted to conduct the syntheses of Vanadium-substituted Gallium Phosphates and try to pick up the single crystal to collect data with SXRD for further illustrating the crystal structure with diamond software to know well its nature. The research result finds out a new type of crystal unseen in the existing literature produced because of the weight changes of C3H10N2, therefore the weight change of a reactor may affect the structure of crystal significantly. In the future, it is expectation that comparison among structures of other Vanadium-Substituted Gallium Phosphates can be made, and the properties of this compound can be measured, and try to find out a brand new type of structure for new exploration by changing the initial reagent. 本研究係透過改變化合物所添加之反應物的比例,以了解反應物比例的改變對晶體的型態與結構的影響。實驗採用中溫水熱反應來從事金屬釩鎵磷酸鹽的合成。並挑取單晶,以X-ray 繞射儀進行數據收集,再以diamond 軟體繪出晶體的結構圖,且進一步得知其性質。研究結果發現,經改變丙二胺的量後,產生不同於文獻上的新化合物,可知改變所加反應物的比例,對於晶體結構有相當大的影響。未來可朝向與其他的釩鎵磷酸鹽做結構上的比較、對此化合物做更進一步的性質測量、改變起始試劑測試,進而得到更新穎的結構形式等部分進行探究。

液滴在我眼前蒸發

本研究的目的在觀察液滴的蒸發過程,探討影響一滴蒸發方式改變的變因。我們利用數位攝影機外加近攝鏡頭,由側面逆光拍攝液滴蒸發過程,並轉錄成電子檔利用電腦協助分析。液滴影像分隔放大投影在方格紙上,以便測量接觸角及高度的變化。結果發現蒸發情形可分為三種:Ⅰ.當接觸角大於九十度時,液滴和界面的接觸線迅速外擴,直到接觸角遞減至90度後定住不動,蒸發終了時,接觸線迅速內縮,留下縮小的實心殘跡。Ⅱ. 當接觸角小於九十度時,接觸線先些微外擴迅速外擴,之後定住不動,直到蒸發終點,液體內縮,留下環狀殘跡。Ⅲ.當接觸角小等於九十度時,接觸線始終定住不變,液滴蒸發後留下原大小的實心班跡。液滴蒸發時接觸角和高度並不是連續變化,而是交互階梯式遞減。本研究的結果可應用在探討噴漆及噴墨印表機的噴墨印刷上。The objective of this investigation is to observe the evaporation of liquid drop and find out the factors that could affect it. A digital camera with micro lens is used to film the process of the evaporation. And a close-up of the sample drop is taken with backlight. The results are analyzed with a personal computer. The magnified images of the drops are projected on grid papers for measuring the changes on contact angles, and heights of drops. We classify the evaporation of a drop into three types: Ⅰ. The contact angle is greater than 90 degrees. At first, the contact line will spread outwardly till the contact angle decrease to the 90 degrees and then be pinned until the evaporation reach its terminal. At last the contact line quickly contract inwardly, and a solid stain remain. Ⅱ. The contact angle is less than 90 degrees. The contact line will spread slightly and then be pinned. At the terminal the liquid contract inward, and a ring-like stain is formed. Ⅲ. The contact angle is equal to 90 degrees. The contact line will always be pinned, and no ring, but spot stain is left. During the evaporation, we discover that the contact angle and the height of the drop do not change continuously but alternatively decrease by steps. The results of our investigation can be applied to the aspects of paint-spraying and jet printers.

對平面結構的石墨烯修飾並應用於直接甲醇燃料電池

此研究希望找到適當的材料和製備方式,提升直接甲醇燃料電池 (DMFC)的工 作效能。 使用石墨烯為基材,將純度99.999%的石墨在高溫下以過錳酸鉀進行氧化,經 剝離後得片狀級氧化石墨烯(GO),然後以氯鉑酸(H2PtCl6)提供正四價的鉑(Pt),還原 在此樣品上成零價鉑金屬做為催化劑的使用。使此樣品(G-Pt)於三電極系統下進行循 環伏安法,分別對硫酸與甲醇進行催化量測此新型材料的氧化電位。對硫酸進行催 化,可得氫的脫附面積;對甲醇進行催化,則是觀察此新型材料的運用成效之優劣。 本實驗進一步於氧化石墨烯(GO)加入苯甲醯氯(Benzoyl chloride)做修飾,合成經 氧化修飾的石墨烯(GO-B),同樣地還原觸媒鉑在此材料上(G-B-Pt)。經電化學分析 後比較是否因修飾後接上苯甲醯氯而有比較好的性能表現。 結果發現,經苯甲醯氯修飾的材料,氫的脫附及甲醇的氧化電位數值表現上高 於未修飾者,說明在三電極系統下,本實驗加入的修飾藥品有助於提升直接甲醇燃 料電池的工作效能,將來可被運用於燃料電池上。

氧化壓力影響基因轉換表現對脂肪分化之作用

細胞脂肪分化是造成肥胖、骨質疏鬆、和糖尿病的重要前置因素。我們若要維持良好身材又想省去減肥藥的問題,那麼我們必須了解造成脂肪化的原因,才可能擁有好的預防之道。利用人類骨髓間質細胞可以分化成骨質與脂肪等細胞的特性,我們研究氧化壓力對間質細胞\r Ras基因轉換表現後骨質與脂肪分化的影響。結果發現以添加超氧根 (O2-,l5nM)形成氧化壓力,可促進正常Ras基因表現的間質細胞朝骨質分化;相反地,超氧根會促進\r Ras基因突變而不表現的細胞,朝向脂肪分化的現象。進一步研究其作可原理,發現氧化壓力可促進 RaS蛋白質啟動細胞外訊息活化酵素(ERK),接著驅動骨質轉錄因子(CBFA1)表現,再到骨鈣蛋白質與骨結節形成。而抗氧化酵素(超氧根轉化酵素;SOD,5OOU/ml)的作用,可以抑制正常Ras基因細胞氧化壓力下骨質分化的進行;但不能防止氧化壓力促進Ras基因突變細胞,朝向脂肪分化的作用。總結而言:Ras基因的表現與否,是決定脂肪分化的關鍵切換點;也是影響氧化壓力對間質細胞朝骨質分化的樞紐。這種基因與氧化壓力互動影響骨質與脂肪分化的剖析,將有助於提醒人們:使用抗氧化劑來調節抗衰老、肥胖、和美容時,必須是在不同情況和不同基因體質的人,有所不同。 \r Human\r mesenchymal stem cells are able to differentiate into bone, muscle, cartilage or\r fat tissues. Our preliminary study with human mesenchymal cell line (HS-5) showed\r that HS-5 cells could differentiate to bone, cartilage and muscle but not fat cells\r as determined by histochemical staining of phenotypes. We have further studied the\r influence of oxidative stress on the switch between bone and fat cell differentiation.\r Results showed that oxidative stress started with exogenous superoxide, produced\r by the interaction of xanthine oxidase and hypoxanthine, promoted the differentiation\r of osteogenic lineage showing expression of osteocalcin and bone nodule formations.\r The mechanism was investigated and superoxide was found to induce ERK (extracellular\r regulated signal kinase) activation; and then the expression of osteogenic specific\r transcriptional factor (CBFA1). A plasmid containing ras-mutant (Ser 17 Asn) which\r can inactivate the expression of ERK was transfected into the HS-5 cells for studying\r the influence of oxidative stress on ras-mutated mesenchymal cells. Surprisingly,\r it was found that oxidative stress did not promote osteogenesis but it enhanced\r adipogenesis from the ras-mutated HS-5 cells. Further studies indicated that superoxide\r neither induced ERK activation nor CBFA1 expression, but it did enhance expression\r of adipogenic specific transcriptional factor (C/EBPα) and lipoprotein lipase in\r the ras-mutated mesenchvmal cells. Taken together, the study model to induce the\r bone cell differentiation from human mesenchymal stem cells may be employed to make\r bone cells for tissue engineering.

吸管笛的諧音之研究與發展

吹長笛時,按同一按鍵,以大小不同的力量去吹,會引發不同頻率的泛音,而通常越用力吹,引發泛音的頻率越高,所以我們想了解為什麼越用力,泛音的頻率會高,其間的關係究竟是什麼?風經過管口會產生各種頻率的噪音,其中某些特定頻率的聲音會因為會在管內形成駐波而放大,所以我們只能聽到某些特定頻率的聲音。當風速增加時,會在管口形成渦漩逸放的紊流現象。其渦漩頻率與流速成正比(註一)。我們以塑膠管實驗。發現以特定的風速引發該基音後,繼續增加風速,當風速達某一定強度時,才會躍遷為下一個泛音的頻率。這個現象告訴我們:在一封閉管下,風速與泛音的關係並非「線性遞增」,而是越「躍遷遞增」的關係。另一個實驗測量不同管長、其諧音之頻率的關係,我們可以得知,越短的管子,因為相鄰兩泛音間頻率差較大,越不易激發更高階泛音。經由這些實驗結果,我們能夠推論:當管子越長、基音頻率越低時,諧音間頻率的差距相對越小,繪出的風速-頻率關係圖應更加顯示了風速與頻率呈正比關係。未來我們可以以閃頻器觀測紊流渦漩的產生,再變化至不同吹入角度,及各式管口造形,這些實驗能協助我們更進一步了解樂器的發聲原理,甚至開發一個以聲音頻率測量風速的儀器。註一:林婉如、張?文2006 國際科工程組佳作作品。When we press the same key and blow a flute using different strengths, we can get different overtones. Usually, the harder we blow the flute, the high the frequency we get. We want to understand why we get a higher frequency when we blow harder into the flute and to understand the relationship between them. When wind passes through the mouthpiece, many kinds of noises will be produced. Some of the frequencies will expand because they will form standing waves in the tube. Therefore, we can only hear certain frequencies. As wind speed increases, a turbulence of the vortex shedding will be formed. The frequency of the vortex shedding and wind speed will be in a direct ratio. We experiment with plastic tubes. When we increase the wind speed and get certain magnitudes, the frequency will jump to the next overtone. The phenomenon shows that the relation, in a closed tube, between wind speed and harmonics is not a linear increase but a transition increase. In another experiment, we measured the relationship between wind speed and different lengths of tubes. We can infer that the shorter the tube, the higher high-frequency harmonics can be produced. Through these experiments, we come to the conclusion that the longer the tube, the lower frequency of the fundamental tone we get and the discrepancy in frequency between harmonics is smaller. Then we make a diagram between wind speed and frequency that indicates that there is a direct ratio between wind speed and frequency. In the future, we can use “” to observe the production of turbulence. Then we can switch to different angles when we blow into flutes. Otherwise, we can experiment with different shapes of mouthpieces. These experiments can assist us to understand more how the instrument sounds. We can develop a device measuring wind speed with frequency.