全國中小學科展

出國代表作品

宇宙演化的黑手

We study the effect of dark energy on the evolution of cosmic structure in a scenario where the dark energy is treated as free particles and thus can be localized. By theoretical derivation and numerical simulations, we found that: 1. The dark energy particles gain kinetic energy from a moving dark matter particle through gravitational interaction. Due to energy conservation, the dark matter particle will slow down with time Ek(t) = Ek0 - 9 × 10-5[|1+3w|ρDE]1.92t where Ek(t) is the kinetic energy of the dark matter particle,Ek0 is its initial kinetic energy, w is the coefficient of equation of state for dark energy, ρDE is the mean energy density of dark energy, and t is the time. 2. The formation history and structure of galaxy clusters are different in the presence of localized dark energy. The more the localized dark energy, the earlier the formation of the cluster core. In addition, the kinetic energy Ek(R) as a function of R will be different if the ρDE is different. Thus we can compare the observed Ek(R) of clusters with our results to deduce the ρDE in our universe. The results here can be applied to the observations in the near future. 我們探討宇宙結構演化受到可局部叢集之黑暗能量粒子的影響。藉由理論推導及電腦模擬,我們發現: 一、黑暗能量粒子會透過重力交互作而從運動中的黑暗物質粒子獲得力學能。因力學能守恆,黑暗物質粒子的速率會減慢,滿足 Ek(t) = Ek0 - 9 × 10-5[|1+3w|ρDE]1.92t 其中Ek(t) 為黑暗物質粒子的動能,Ek0 為其初始動能,w 為狀態方程式係數,ρDE 為黑暗能量的平均密度,t 為時間。 二、星系團的形成過程及結構,會因可局部叢集之黑暗能量的存在而改變。黑暗能量越多時,星系團的核心會越早形成。而且動能 Ek(R) 隨著至星系中心距離R 的變化,會因 ρDE 的不同而不同,因此可以將量測到的 Ek(R) 和這裡的結果比對,推導出宇宙中的 ρDE 。 這些研究成果將可直接應用在未來的觀測結果上。

氣體式毒氣淨化器

由於一氧化碳之毒性氣體無色無味且不易發現,對我們的生活造成嚴重的威脅,本作品建構出一套可發布警報、能在極短的時間轉化一氧化碳的毒氣淨化器,也進而說明其獨特性與前瞻性。 \r 本研究的核心,在於室溫下能啟動金觸媒的轉化機制,亦針對平常少被討論、以含浸法製作的金觸媒加以分析和提升,發現利用NH4OH 鹼溶液處理方式並以573K 的O2?燒處理活化觸媒,能有效提升1%Au/Al2O3觸媒對CO+O2的反應活性。使用相同製備方式在Au/TiO2觸媒上於250K 即可達到100%的CO 轉化率。創造一個簡易的流程來製備高活性的觸媒,其作用活性的範圍溫度也相當廣。 \r 本淨化器在實驗中的運作狀況下,能完全轉換一氧化碳含量至低於中毒安全標準內,本系統還設計一道封閉閘門,有利於金觸媒的活性封存。 \r 本作品具有較低成本的觸媒量產流程與材料,觸媒本身也可回收後再活化,此能更符合觸媒市場需要;機體器材替換容易、安全性高等能有效避免中毒意外的發生。

結合Hamiltonian與Hiroimono的路徑研究

Hamiltonian和Hiroimono路徑問題都有百年以上的歷史,且沒有直接解決方法,可能因為是題目本身的條件在討論時尚不足解決問題,現階段只能用電腦去跑。

Mechanism of the subcellular localization of the actin binding protein adducin

Adducin蛋白在細胞骨架的調節上扮演著重要的角色。然而,近來有許多研究指出,骨架蛋白也會出現在細胞核並參與轉錄調控,因此本研究的目的即在探討adducin蛋白是否會進入細胞核中,並參與轉錄調控或具有其他功能。在本研究中,我們將綠色螢光蛋白(GFP)標示的adducin質體DNA,利用轉染技術送入老鼠纖維母細胞株NIH3T3中表現。NIH3T3細胞原本並無adducin蛋白的表現,在共軛焦顯微鏡下觀察,野生型的GFP-adducin蛋白會表現於細胞核與細胞質中。由於adducin蛋白尾端序列攜有可能往核內運輸的訊號,於是將位在此一訊號中的離胺酸718及離胺酸719進行突變,結果發現此一突變株只能在細胞質中表現。此外,蛋白磷酸脢C(protein kinase C)已知能磷酸化adducin蛋白在絲胺酸716及絲胺酸726的位置,於是假設其磷酸化是否與其在細胞內的分布有關。將adducin的絲胺酸726置換成丙胺酸,並不影響其在細胞內的分布。然而將絲胺酸716置換成丙胺酸後,則完全只在細胞核中表現。由於adducin可分布於細胞核,因此我們懷疑adducin蛋白可能與細胞分裂有關,於是本研究利用流式細胞儀分析adducin轉染後NIH3T3細胞的細胞週期。流式細胞儀的分析結果顯示,攜有GFP-adducin或其突變株的細胞與未經轉染的NIH3T3細胞的細胞週期並沒有顯著差異。其次,為了避免因轉染的效率不高而造成統計上的誤差,我們利用顯微鏡追蹤技術觀察攜有GFP-adducin的細胞株,結果顯示攜有adducin突變株的NIH3T3細胞株仍能正常分裂。再者,因為adducin能與細胞骨架中的肌動蛋白結合,所以adducin不同的分布位置可能影響細胞附著與細胞展延的效率。細胞展延試驗的結果顯示,adducin及其突變株對細胞附著與細胞展延的效率並無明顯的影響。本研究的結果證明,adducin的確帶有往核內運輸的訊號,其在細胞質中的分布可能也同時受到絲胺酸716磷酸化的影響。然而adducin的功用似乎與纖維母細胞的分裂與展延無明顯的關聯性。Adducin, an actin binding protein, is known to play an important role in the regulation of the membrane cortical cytoskeleton. More and more evidence indicates that proteins involved in the cytoskeletal regulation could also reside in the nucleus and participate in gene regulation. Thus, the goal of this study is to examine whether adducin is expressed in the nucleus and involved in certain nuclear events. In this study, adducin and its various mutants were fused with green fluorescent protein (GFP) and transfected into mouse NIH3T3 fibroblasts which do not have endogenous adducin for monitoring their subcellular distribution under a laser scanning confocal microscope. The wild-type GFP-adducin was found to be present both in the nucleus and in the cytoplasm. The COOH-tail of adducin contains a motif analogous to the nuclear localization signal (NLS). Mutation of two lysine residues (lysine 718 and lysine 719) located within this motif abolished the nuclear localization of adducin. Moreover, adducin is known to be phosphorylated by protein kinase C at serine 716 and 726. Substitution of adducin serine 726 with alanine had no effect on its subcellular localization. In contrast, substitution of adducin serine 716 with alanine led to only nuclear expression. Nuclear localization of adducin renders it possible that adducin may be involved in the regulation of cell division cycle. For cell cycle analysis, flow cytometry was applied. The results of flow cytometry indicated that expression of adducin and its mutants in NIH3T3 fibroblasts did not affect their cell cycle progression. To further examine the effect of adducin on cell division, NIH3T3 cells transiently transfected by adducin were monitored by time lapse video microscopy. The video clearly showed that the cells with GFP-adducin underwent cell division to generate two daughter cells. Since adducin is well known to bind to actin and thereby regulate microfilaments, we wondered that expression of adducin in NIH3T3 cells might affect their adhesion and spreading onto extracellular matrix proteins. The results of cell spreading assays showed that adducin appeared not to affect cell spreading. In conclusion, our results demonstrate that the subcellular distribution of adducin is likely regulated by two signals, one is the nuclear localization signal and the other is the phosphorylation status of the serine 716. However, enforced expression of exogenous adducin in fibroblasts such as NIH3T3 cells does not alter their cell cycle or cell spreading on fibronectin.

橡膠鍵鏈結構與自由能的關係

受應力拉伸時,橡膠溫度明顯上升;縮放回原長,橡膠溫度驟降。由文獻得知橡膠內部具有特殊的鍵鍊結構,在一般的情況下,交鏈分子糾結成一團,狀態複雜;受外力拉伸時,交鏈分子依橡膠長度之增加而伸展,排列較為整齊,狀態之複雜度減小。根據熱力學第一定律,當內能變化為零,則外力作功會造成能量變化。在定溫之下,橡膠內能變化為零,當其受應力拉伸,使其內部交鏈分子排列複雜度降低,造成橡膠熵值減小,而有能量(dQ=TdS)的釋出。測量此一能量dQ 變化,即可計算出熵與狀態數之變化The temperature of rubber rises as it is stretched, its temperature comes back again while it restores to its original length. It is known that the rubber is consisted of long-chain molecules, the long-chain molecules strangle each other at normal state, however, they become more order when the rubber is stretched. Based on the 1st law of thermodynamics dU=dQ+dW, The deformation caused by applied force supplies energy to the rubber and reduce its entropy, the heat dQ (=TΔS) released by the reduction of entropy causes the temperature rise of rubber as dU=0. We report the study on the correlation of thermal properties and the molecular network in rubber, from the measurements of temperature change, the changes of entropy and the changes of states’ number were estimated.

竹嵌紋病毒及其衛星核酸5'端非轉譯區與複製競爭關係之探討

RNA 病毒在複製過程中容易產生錯誤,導致其族群具中有很大的遺傳歧異度,累積的錯誤再加上選汰的壓力造成往後之變異。由於RNA 基因體之病毒變異較大,使得RNA 病毒在單一寄主上具有quasispecies 的特性,提供病毒產生新基因體的機會以適應環境或演化成新病毒。例如流行性感冒病毒與之前造成恐慌的嚴重急性呼吸道症候群病毒(severe acute respiratorysyndrome,SARS)以及禽流感病毒 (avain influenza virus) 皆為RNA 病毒,意味著RNA 病毒知不穩定性,並容易造成一些目前我們無法及時反應的危害。大部分的植物病毒又為RNA 病毒,本研究將以竹嵌紋病毒 ( Bamboo mosaic virus , BaMV )及其衛星核酸 (satellite RNA, satBaMV)為材料,進一步探討核?酸序列之變異對其族群在複製競爭上的影響。

極速火龍-利用軟片顯影法觀測氫爆的火焰傳遞

用塑膠軟管作為氫爆安全反應器,從封閉端點燃氫氧預混氣,管中火焰\r 傳遞快速,肉眼難以觀察,因此研製「氣爆顯影記錄器」來觀測,如下圖,\r 光纖導引偵測點的火光至暗箱,記錄於高速旋轉的軟片,從光電轉速計讀取\r 轉速,軟片沖洗後量測各顯影間距,可得火焰位置與時間的關係圖,量測時\r 間最小刻度可達2. 2 微秒。\r 解讀軟片的顯影,得知氫爆初期,火焰加速傳遞,大部分在25cm 位置\r 左右,火焰的速率出現急速飆升(爆燃轉變為爆震),而且火光亮度也急速升\r 高,有時火焰速率出現飆升過高,再回降趨於穩定?的現象,在50 cm 位置\r 左右,火焰進入等速傳遞階段,此階段有穩定的火焰模型,火焰頂端的亮度\r 最高,往後亮度遞減。

無機砷與硒對染色體傷害之交互作用

中文摘要 重金屬對人體傷害的無遠弗屆-人人皆知,根據流行病學的研究指出,長期處在 重金屬含量過高之地區,易造成生理病變。比方說,長期生活在砷含量高的環境中, 易導致肝臟、周邊血管及神經系的損害,各種癌症的發生機率也大為提高。 本實驗以中國倉鼠卵巢細胞(CHO-K1)為材料,利用微核偵測技術(Michronuclei, MN)及姐妹染色分體互換(Sister chromatid exchanges, SCE)之誘引來探討亞硒酸鈉 (Sodium selenite, NaSeO2) 及亞砷酸鈉(Sodium arsenite, NaAsO2) 的交互作用 (interaction)。實驗結果顯示亞硒酸鈉本身不會造成MN 的增加,但讓SCE 頻率增加; 亞砷酸鈉會誘引增加MN 和SCE。亞硒酸鈉前處理不會減少亞砷酸鈉誘引之SCE 和 MN,但可微微降低亞砷酸鈉抑制雙核細胞(Bunucleated cells, BN)的形成,但是不明 顯。本實驗結果未能看出亞硒酸鈉前處理與亞砷酸鈉有明顯的交互作用,但發現亞 硒酸鈉會增加SCE 頻率,因此亞硒酸鈉做為保健食品值得進一步的關切及探討。 英文摘要 It is well-documented that exposure to heavy metals could cause seriously adverse effects to humans. Epidemiological evidence has shown that illness is frequently observed in residents living long-term in heavy metal contaminated area. For example, arsenic exposure was associated with increased incidences of liver diseases, peripheral vascular and neurological diseases, as well as cancers. In this report we investigated the interaction of selenite and arsenite on micronuclei (MN) and sister chromatid exchange (SCE) induction in Chinese hamster ovary-K1 (CHO-K1) cells. The present results demonstrated that sodium selenite by itself did not induce MN, but it did cause the increase of SCE frequency. Sodium arsenite significantly induced MN and SCE in CHO-K1 cells. Pretreatment of CHO-K1 cells with selenite could not reduce MN and SCE frequency induced by arsenite, but slightly prevent the cells from arsenite-induced inhibition of binucleated cell formation. In the present study, no significant interaction between sodium selenite pretreatment and sodium arsenite was observed. However, sodium selenite was unexpectedly found to enhance SCE frequency in CHO-K1 cells. The application of selenite as health protection agent warrants our concerns and further investigation.

以Hα、K-Line、UV、Soft X-ray波段太陽影像試求太陽光球層之上的徑向較差自轉.

本研究以網路上Soft X-ray、UV195Å、K-Line、Hα波段太陽影像上黑子,光斑經度位置的逐時變量,試求太陽自光球層以上各層是否有越高層轉速越慢的現象?經試用數種方法求大量黑子、光斑位置,最後以省時,且誤差減小的"由PhotoShop軟體讀出黑子、光斑在圖檔中位置,於EXCEL軟體中套用日面座標公式",以Peter Meadows的黑子定位程式抽樣對驗,來求其經緯度值。結果:在任何緯度,光球層以上各層轉速不同(徑向較差自轉現象),但並非越高層越慢,而是在大部分緯度處其各層速度變化呈 的快慢交替現象。

灰階影像內容之檢索技術

資訊時代的來臨,促使我們的社會型態大幅改變,無一不朝數位化的方向邁進。網際網路與資訊科技的快速發展,近年來影像資料庫和數位圖書館大量的成立,關於影像資料檢索的研究已漸漸成為一門極為重要的研究議題。在本研究報告中,我們提出一種植基於向量量化編碼法的灰階影像檢索技術。向量量化編碼法是一種極為簡單的影像壓縮技術。我們應用這個編碼法,來萃取出灰階影像內容的特徵值。同時我們也計算出整張影像與影像中間位置的像素平均值,作為日後檢索影像時過濾掉影像資料庫中不需要比對特徵值的依據。\r 我們所提出的方法能有效地萃取影像內容的特徵值並且讓使用者可以快速且正確地查詢到所需要的影像。當影像資料庫中存在與查詢影像完全相同的影像時,我們的檢索技術都能在第一時間第一順位檢索出這張影像。即便影像資料庫中不存在與查詢影像完全相同的影像時,我們的檢索技術平均74.3%也能在第一時間前五個順位檢索出最相似的影像。\r \r With the coming of the information age, our sociological system change extensively, and everything has moves toward digitization. Due to the rapid development of Internet, information technology, the rapid growth of image databases and digital libraries recently, the related researches of image retrieval have become a very important issue. In this memoir, we propose an image retrieval scheme based on the vector quantization to retrieve similar images from the image database according to the pre-collected image features. Vector quantization is a very simple image compression scheme. We have applied vector quantization to extract features from grayscale image. In order to speed up the retrieval process, we also calculated the mean pixel values of whole images and the central part of the image to filter the images, which are significantly dissimilar to the query image.\r The experimental results show that our proposed approaches can effectively extract features from the image and enable users to retrieve images from image database quickly and accurately. When images stored in image database match query image, the proposed scheme can instantly retrieve the stored image at the first rank. Even though images stored in image database query image exactly, the proposed scheme can instantly retrieve the stored image over 74.3% at the first five ranks.