全國中小學科展

臺灣

液滴撞擊固體表面時的傳播現象

在這份報告中,藉由高速攝影機,我們可以更清楚地觀察到液滴在撞擊固體表面瞬間的形變現象。分析以不同的液滴、不同的撞擊表面、不同的瞬間撞擊速率以及不同溫度的金屬表面,並探討在不同的條件下,韋伯常數(Weber Number)與水滴散開之間的關聯。實驗結果顯示,當表面張力與密度比值大,或當液滴速度快時,液滴形變越明顯,但其形變量有一最大值,而其薄水層傳播速度會隨時間增加而減少,但其環狀波在彈回時幾乎是呈等速度的彈回。若是液體表面張力較撞擊面附著力大者,或撞擊面溫度超過攝氏400度時,在其薄水層達到最大直徑時,便會向內收縮,形成一顆水珠。

基因突變對線蟲(Caenorhabditis elegans)的神經系統退化突變株的搜尋以及對其

This research is mainly in observation with Caenorhabditis elegans ’s genetic mutation caused via nervous system abnormal character. In the study, I the sample have been cultivated purified and add some chemical material EMS to speed up C.elegans mutation. Then based on the character to further analysis what causeof gene deal with mutation and observe the effects in heredity. The research has two stages, on the first stage of study the mainly target is to both search and purify the mutation of C.elegans. The second stage is based on the exploration of mutation’s searching and purifying. Because the certain mutation bodies aren’t easy to find out, the project is still on progress at the beginning of second stage, and we conclude some heredity special cases in preliminary of study. 這個實驗主要是觀察並針對線蟲因為基因的突變所產生的神經系統異常的變異性狀,在實驗中我先將樣品線蟲培養並純化至一定數量,並加入適當藥劑EMS造成其突變,經篩選並分析此性狀,進而找出造成其突變之基因,以及觀察此性狀對遺傳表現所造成的影響。該計畫分成兩階段,第一階段的實驗重點是在突變株的搜尋以及純化上,第二階段則是在突變基因的探討上,由於特定突變株的搜尋並非容易,所以目前計畫只進展至第二階段的遺傳實驗初期,對於其遺傳特徵與突變形式上已有了初步的分析,但尚未定位出該基因的位置。

植物miRNA的特殊長度─生成與演化

基因靜默為各種生物普遍擁有的調控機制,是以microRNA (miRNA)和Dicer-Like (DCL)與Argonaute (AGO)等數個蛋白質來完成。在植物,miRNA大多是由DCL1截切前驅物所產生,因DCL1具有21-nt 分子尺,所以絕大多數miRNA的長度為21nt。然而,其他特殊長度卻也有一定比例的存在,且可能有特殊的功能。最新研究發現22nt的miRNA可誘發更多的小片段干擾核酸來造成大量而強烈的基因靜默;然而,一般21nt的 miRNA卻無此功能。本研究以生物資訊的方法分析大量資料庫,並以分子生物學實驗佐證,探討特殊長度miRNA的生成、功能與演化。結果發現,20nt的miRNA可藉由對稱性與非對稱性縮短產生,這是RNA結構研究的新發現。功能上,20nt的miRNA與生長發育有關,22nt的miRNA則多與逆境反應有關;在演化上,長度20nt的miRNA呈現高保守性,而大部分22nt的miRNA則呈現高度物種專一性,為演化快速的特殊長度。

小鼠骨骼肌細胞分化過程中SMN 基因mRNA剪接型之變化

脊髓性肌內萎縮症為常見之體染色體隱性遺傳性疾病,在台灣罹病率約為萬分之一,罹病者會造成幼兒期致死或因肌肉萎縮導致殘障。大多罹病者致病成因為SMN基因突變,脊髓前角運動神經元凋亡退化,導致上下肢肌肉發生漸進性萎縮

狂舞飛圈-簡單飛機的飛行動力研究

本實驗主要是探究雙圈圈簡單飛機的飛行原理,歸納圈圈結構對飛行距離、升力的影響,以及氣流流經機體時發生的作用。研究結果如下:一、實際發射,歸納影響滑行距離的變因。1. 前後圈直徑比值約為0.8 時滑行距離為最大。2. 前後圈寬度比值越接近1 時,滑行距離越遠,但影響不大。3. 圈圈間隔在21cm 時,滑行距離最大。二、設置風洞,模擬飛機飛行,測量升力1. 圈圈寬度越大,升力越大。2. 升力最大值出現在圈圈仰角25 度左右,風速越快,升力越大。3. 鋁片仰角在20°時升力最大,升力與角度的關係式為 F = 5×10?7θ4 + 4×10?5θ3 ? 0.0083θ2 + 0.2615θ + 0.13744. 風速越快,升力越大,在仰角20°時升力與風速的關係大約為F = 0.4579V2 - 0.9231V +1.4772 。5. 鋁片面寬每增加1cm,升力也增加0.1513gw。前後長每增加1cm,升力即增加0.1263gw。三、設置蒸汽氣流,觀察簡單飛機的氣流場1. 蒸汽流通過圈圈時,會發生附壁現象,而且簡單飛機使氣流往下偏折,飛機得到升力。四、理論演繹︰1. 以康達效應的理論推算出升力,與實際測量得的升力約相等,驗證升力確實由康達理論造成。2. 墊高簡單飛機前圈,使得軸線提高,確實影響了飛行距離,墊高1cm 以內,飛行距離均增加了,以實際的改進證實升力確實是康達效應。This experiment mainly discusses the flying principle of the simple plane which is made up of a straw with two paper circles, one bigger than the other, stuck on both two ends of it. We first launched the simple plane actually and concluded the factors which influenced the sliding distance of the plane, including the distance between two circles, diameter and width of the two circles. Second, we set up a simple wind-tunnel and simulated the flight, in order to measure the strength of lift. Third, we set up the steam air flow and observed the change of the air current in the steam flow while flowing through the plane. The Phenomenon of Wall Enclosing happened and made the flows downward, and the plane gained the lift at the same time. Finally, we deduced that there are two sources of lift and Benoulli's law is not suitable for it. The Coanda Effect can be applied to figure out 54 percent of lift. And the current, blocked by the plane, also offers some lift. In order to prove that the Coanda Effect does effect, we padded the first circle to enlarge the angle of elevation of the axis of the two circles. It really affected the sliding distance of the plane. While the first circle is padded up within 1 cm, the sliding distance of the plane increases. Practical improvement proves that Coanda Effect accounts for the lift.

機能性材料的光學性質

本實驗使用磁流變流體(Magnetorheological fluid, MRF)來估查其磁場作用下的光學性質。本實驗採用Lord公司的MRF-132LD磁流變流體加以稀釋到不同的重量濃度,並以氫氟酸蝕刻玻片產生不同的厚度。吾人觀察到濃度參數以及厚度參數均對MRF薄膜的光繞射產生影響。膜厚越薄,產生的繞射較明顯,而重量濃度較小的容易亦有較大的繞射角度。吾人亦移動上下兩玻片相對位置,施加剪力的作用,繞射現象也產生明顯的改變。\r The Magnetorheological fluid (MRF) is used to observe the optical properties under the vertical magnetic field , The MRF-132LD from Lord Company is used, The MRF is diluted to different weight ratio of particulate and carrier fluid . The different thicknesses of the MR thin film are also made with the diluted MRF. The concentration of the MRF and the thickness of the thin film are both found to have significant effects on the optical diffraction phenomenon. The optical diffraction is also found to be affected by the applied shear force to the thin film.

磁場中的離子轉速-探討離子遷移速度變因

帶電的離子受到垂直的磁場與電場作用,會因為受到洛倫茲力而產生有趣的轉動現象。我們利用上述原理設計簡易的裝置設備,探討電解質溶液不同濃度、不同離子電荷數,受到不同離子間靜電力,產生不同的離子移動速度。經由所測量的時間與圓周運動的距離,可計算電解質的絕對遷移速度。由實驗結果推論在固定電場下,當電解質濃度降低,正、負離子間的相互作用力降低,離子遷移速度(migration velocity)加快,莫耳電導率 Λ(mole conductance)也隨之增加。同濃度時,電解質2-1 價型硝酸銅與2-2 型硫酸銅離子強度(ionic strength)不同,2-2型硫酸銅離子強度較大,遷移速度較小,莫耳電導率Λ 也較小。Because of the effect of Lorentz force, charged ion will have interesting rotation under the vertical magnetic and electric field. We use the above principle to design a simple instrument or tool, in order to evaluate and study the formation of different ionic mirgration velocities. The velocity of the charged ion in the instrument is affected by differences in the electrolyte, the charge differences of the ion tested and the differences in electrostatic forces between ions. From the experiment we can deduct that at a fixed constant electric field, when the concentration of the electrolyte is reduced, the interaction of forces between positive and negative ions will be reduced. When the migration velocity of ions increase, the mole conductivity Λ (mole conductance ) will also increase. At the same concentration, the ionic strength between copper nitrate ( 2-1valency type ) and copper sulfate ( 2-2 valency type ) are not identical. Copper sulfate, a 2-2 valency type has higher ionic strength, the velocity is slower and the mole conductivity Λ is also smaller.

蝴蝶眼斑的探討

在眾多的蝴蝶中有不少是具有眼斑。傳統上認為眼斑的功能是驚嚇天敵或欺騙天敵。有關眼斑本身結構的瞭解很少。我們利用臺灣及馬祖產的蝴蝶,分別記錄圖鑑上峽蝶、眼蝶及灰蝶合計 60 種以上,以及鳳蝶幼蟲七種的眼斑特性。記錄的眼斑特性包括數目、組成的色彩結構,以及記錄眼斑在翅的腹面或背面明顯。進一步測暈孔雀峽蝶、台灣波眼蝶、蘇鐵小灰蝶等三種蝴蝶的眼斑和翅面積。眼斑在腹面及背面都有,但以腹面明顯者佔多數,而眼斑數 l 一 7 個都有,在後翅者佔多數。眼斑慕本是由數個同心圓組成,分別為輪廓、眼白、虹彩及障孔。在峽蝶及眼蝶的結構都相當完整,輪廓為褐或深褐,眼白為黃色為主,虹彩都為黑色或深褐色,障孔為白色或淡藍色。在灰蝶的眼斑較不完整,大都輪廓不清晰,眼白的黃色或橙色部份比例高,但都缺少障孔。幼蟲有眼斑成蟲不一定有。鳳蝶的幼蟲( 8 種)都為綠色,其眼斑輪廓黑色,眼白為白色及紅色但明顯比上述成蟲的眼斑之眼白部位要小,而黑色的虹彩都很大。幼蟲的障孔為白色的細線形,我們認為這和立體形狀的幼蟲及成蟲平面翅的差異所造成,在文中也討論到水棲蝶魚的眼斑和蝴蝶眼斑的差異。眼斑和翅面積的相關分析結果變異很大,在統計上正相關及負相關都有。眼斑數目的不定及和翅面積並沒有一定關係,我們討論到蝴蝶的眼斑在不同種類有些可能有求偶生殖上的功能。這方面值得科學家大量投入研究。Quite a few species of butterflies have colorful eyespots on their wings. The main functions of these eyespots were considered to startle or deceive predators by most scientific researchers. In fact, only limited literatures dealt with the basic structure and color patterns of butterfly eyespots. The purpose of this study is to study the basic structure and color patterns of these eyespots. We measured the surface area of eyespots v.s. wings from specimens. From the color plates of Taiwan and Matsu butterfly field guide, we recorded the eyespots either on ventral or dorsal side of wings, and the color patterns for more than 60 species. \r The number of eyespots on wings varies from I to 7 among individuals we checked. Majority of eyespots were found on ventral side of wings. The basic structure of eyespots were formed by I to 3 concentric circles, i.e., outboundary, cornea, iris and pupil . Pupil was not found in certain species. The color in cornea section is yellow and in iris is black or dark brown. The contrast in these two areas is quite prominent just as the contrast showed in warning coloration of after animals. The pupil is either white of light blue. Caterpillars with eyespots were found in Papilionidae, their adult stage were without this character. We checked 8 species of caterpillars, their basic structure of eyespots were similar to other butterflies, with cornea, iris and pupil. The cornea is either red or white color, and the iris is black in colors. The ratio(iris/cornea) is much higher in caterpillar than in butterfly. The pupil is a thin thread shape instead of a tiny spot like the one in butterfly wings. We discussed the difference of pupil between juveniles and adults from the aspect of dimension structure of a subject. In the paper we also discussed the difference of eyespots between butterfly and butterfly fish in the coral reef. Base on the no significant relationship between the surface area of eyespots and wings. We suspect that butterfly eyespots may have another function, such as intersexual selection between males and females beside startling and deceiving predators.\r

費曼三角形的推廣

We inferred the original Feynman triangle theorem from equilateral triangle into common triangle and from same ratios of dividing points into different ones. The conclusions are below: 由原始費曼三角形原理中的正三角形等比例分點問題,推廣至一般三角形的分點等比例及不相同之比例,得到如下之結論:

東方帆船推進原理探討

本文研究風洞中之風帆在不同條件下,受風吹拂所產生之升力與阻力關係,並探討及成功 的以數學模型解釋其原因,此研究結果可應用於帆船帆面之設計。其主要探討之變因為以下 之五種: (一) 風速大小對帆船帆面之受力關係:當帆面與風向垂直時,在低風速時,實際測值較接近 風速的一次方的函數關係。高風速時,實際測值接近為風速的二次方的函數關係。 (二) 帆面積大小與受風推進力之關係:當帆面與風向垂直時,在風速固定風速下實驗,得到 面積與風對帆推力成正比。 (三) 順風航行時,帆面之攻角(θ)與受風推進力之關係:航行方向的力與sin 2θ 成正比關係。 (四) 側風航行時,帆面之攻角(θ)與受風推進力之關係:帆面在攻角大於 45°時,航行方向的力與sin θcosθ 有相當程度的吻合,而在攻角0°~45°之間則與飛機攻 角升力資料相接近。 (五) 初步探討雙桅帆與單桅帆面受風推進力之不同:發現其在側風時能有效的減少失速的現 象,在帆面高攻角時,能減少失速現象,依然可以持續穩定的航行,我們也可推想出飛機 的機翼前段的縫翼功能也是如此。 This article is derived from our research of relation between lifting power and its resistant power produced via wind-blow in a wind tunnel under different terms and condition, also to discuss and to explain their causes successfully via mathematics models, thus, the result of this study may be applied in designing of sail-surfaces of sails boats. Its major discussion can be included into the below 5 kinds: - Relation of (1) Relation of sizes of wind-speed against reacceptance of aerodynamic forces over sail-surface: When sail-surface and wind direction becomes horizontal, under low coin-speed, practical measured-value is rather close to wind-speed's linear function relation. When in nigh wind-speed, the practical measured-value is rather close to wind-speed's quadratic function relation. (2) Relation of size of sail-surface and pushing power of wind: When sail-surface and wind direction becomes horizontal, an experiment was made under fixed wind speed, the result obtained is sail-surface size and pushing wind power toward sail is in direct proportion. (3) When it is in “round-the-clock wise” navigation the angle of attack (θ) of sail-surface and the relation with wind's pushing power: Strength of navigation direction and sin2θconforming direct proportion. (4) When it is in side-wind navigation, the angle of attack (θ) and pushing power by wind relation; When the sail surface is in the angle of attack (θ) greater than 45o, the navigation direction power and sinθcosθhas certain extent of conformity, and between angle of attack e 0o-45o, happens to be very appropriate with aircraft's angle of attack and lifting power data. Fundamental discussion of Double Masts Sail boats and Single Mast Sail boats comparing differences of wind-aided pushing power: It was found that stall phenomena could be decreased effectively, when it is side-winded, especially, when the sail-surface is at high angle of attack, it could decrease Stall phenomena, and could maintain stable navigation. We can also assume that the front section of aircraft aide-wing’s function exactly the same.