金字塔附近的流體力學效應
陸地上的金字塔無時無刻沒有受到氣體的包覆,這個實驗透過風洞模擬金字塔模型,在流體中的壓力變化,並藉由煙線來觀察流體的移動情形,可具體看到當流體經過物體週遭時流場的改變。經由測量壓力,可更深入的探討風速與壓力的關係。在實驗中,可發現當流體迎面而來,在金字塔後方形成的流場變化中,以渦流最易觀察;且透過壓力的測量,發現模型的前、後方,會有明顯的壓差,會對模型造成力矩,可能會使金字塔結構不穩定。越往金字塔上方壓差越小,因此其受阻力所產生的合力矩應較同底面積、同高的長方體小,故金字塔可以長久在沙漠中屹立不搖。此外,流體流過模型兩側會產生分離的情況,分離點的位置會影響渦流區的大小;一般而言,分離點發生在物體的越後方,尾流的尺寸越小,壓差所造成的阻力越低,實驗中發現流速對分離點的位置影響不大,金字塔的擺放形狀卻會對分離點的位置產生明顯的影響,所以越流線型的物體,其受到壓差所產生的阻力越小。希望透過以上的研究,能夠對金字塔周圍複雜的流場有更深入的了解。The pyramid on land is constantly surrounded by gas. Using the wind tunnel, we can investigate the distribution of pressure surrounding the model of pyramid; furthermore, we can discuss about the relationship between pressure and wind velocity. In addition, with the smoke wire, we can visually observe the dynamic flow filed. In our experiment, we discovered that when fluid comes, there will be obvious difference of pressure between the front and the back of the pyramidal model, causing a torque to the model. At higher parts of the model, there is less difference of the pressure, so the resulting torques of a pyramid should be less than that of a cuboid. Therefore, a pyramid can stand in the desert for a long time. Besides, when the fluid flows through the two sides of the model, it will separate, and the position of the separation points will influence the size of the turbulence area. Generally speaking, the farther the separation points are to the back, the smaller the size of the turbulence area, and the less the drag caused by the difference of pressure. With the study above, I expect to have more understanding about the complex flow field of pyramid.
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.
繪身繪影-正三角形磁磚設計方法與碎形密舖之研究
本研究主要以正三角形作為基本單元,透過窮舉討論得到正三角形邊的作用方式只有五種,再經由排列組合歸納出11 種正三角形密鋪磁磚設計方法。進一步,運用我們的研究結果,配合數學簡報系統製圖,創作新圖樣,也彌補了Escher 在手繪時所造成的誤差,達到完全密鋪的效果。碎形磁磚的部份,我們也依據其背後的數學理論創作幾套結構圖,利用結構解析,碎形密鋪磁磚將變得十分容易,學習者將可輕鬆製作富有創意的新圖樣。 ;This research mainly takes the regular triangle as the basic unit. Through the enumeration, we obtain that there are only five operations for edge of the regular triangle, and then 11 kinds of regular triangle design methods are induced. Even more, utilizing our findings and Mathematical Presentation System (Math PS), we created the new pattern which makes up Escher’s errors and achieves the tiling. As to Fractal Tiling, we create several sets of structure drawings according to its mathematics theory. Using structure analysis, the Fractal Tiling will become extremely simple, and the learner can make the rich creative new pattern easily.
直接乙醇燃料電池之觸媒層研究
直接乙醇燃料電池以酒精與氧氣透過氧化還原反應產生電能,但化學反應緩慢,需利用觸媒以增加其速率。本實驗目的在於盡可能找出一個表現最佳的觸媒。本實驗利用活性碳粉作為觸媒(鉑、錫)的載體,以酸性(HNO3)與鹼性(NaOH)環境分別處理碳粉,再以含浸法與多元醇含浸法將觸媒還原。我們得到以HNO3 處理的碳粉無法保有原碳粉的型態,較利用NaOH 處理為差。在觸媒製備方面,多元醇含浸法還原效果比含浸法可得到較小的觸媒尺寸,在本實驗中,溶液中鉑與加入的碳粉重量比為3:7 時,可得到最大的反應面積。此外,當鉑與錫原子數比為4:1 時,可得到最大的乙醇氧化電流。Direct ethanol fuel cell is a kind of power source which generates electrical power by a redox reaction involving ethanol fuel and oxygen. However, this reaction takes place slowly; therefore, catalyst is needed to improve its activity. The goal of this project is to get an optimize catalysts ratio to obtain the best catalyst activity. Activated carbon is used as the support of catalyst (platinum and tin) particles in this project, which is pre-treated in acid (HNO3) and alkaline (NaOH) solutions respectively. Then, the precursor is reduced by impregnation and EG-impregnation. We learned that activated carbon pre-treated with NaOH activates better than which pre-treated with HNO3 because the latter bear less resemblance than the former. As for the catalyst, the results of EG-impregnation show smaller size of catalyst particles than those of impregnation. In this project, when the ratio of the weight of platinum and activated carbon added into the solution is 3:7, we can get the largest surface area. In addition, when the ratio of the amount of platinum and tin atoms is 4:1, we can get the largest current of ethanol oxidation.
豆類澱粉?抑制劑之研究與應用
豆類澱粉?抑制劑具害蟲防治與血糖調節之功效。本研究從台灣五種豆類中進行澱粉?抑制劑活性初篩,篩選出四季豆對麗蠅的澱粉?有明顯的抑制效果,粗萃後分離純化出單一蛋白質,經胺基酸定序結果得到兩個多?片段-VGLDFVLV 與TETSFNIDG , 與已發表文獻比對推測為腰豆澱粉?抑制劑—αAI-1。經測試發現此抑制劑在85℃時仍具備抑制果蠅澱粉?之活性,為一熱安定性蛋白質,其抑制作用受pH 值影響很大,在偏酸性環境下的效果最好,且其抑制作用具特異性,可明顯抑制果蠅、入侵紅火蟻、白蟻、蟑螂及麵包蟲等昆蟲的澱粉?活性。在調節血糖方面,本研究利用豬胰臟澱粉?進行抑制活性測試,篩選出四季豆、花豆與黑豆對豬胰臟澱粉?有明顯的抑制效果,進一步利用Wistar 品系大鼠,進行豆類澱粉?抑制劑降血糖功效之活體試驗,將四季豆、花豆和黑豆粗萃經濃縮乾燥後餵食大鼠,發現花豆、黑豆在第一小時具有顯著抑制血糖增加效果;四季豆、黑豆在第三小時血糖回升,花豆仍可維持較低血糖濃度。此初步結果顯示,花豆粗萃物可能具備減緩消化吸收作用,具應用潛能,其確切分子作用機制值得深入探究。Amylase inhibitors can be applied in pest control and glucose adjustments. The study screens Phaseolus vulgaris from five Taiwan’s beans that has the most significant inhibition towards Chrysomia megacephala. The protein was isolated and sequenced two fragments, -VGLDFVLV and TETSFNIDG, highly homologous to that of αAI-1 from Phaseolus vulgaris. The pure protein still inhibits the amylase from Drosophila melanogaster at 85℃, suggesting it is thermal-stable. Its activity was specific and was affected by pH, reaching the peak in weak acidic condition. It obviously inhibits amylases from D. melanogaster, Solenopsis invicta, Odontotermes formosanus, Periplaneta Americana Linnaeus, and Alphitobius sp. In addiction, the study points out Phaseolus vulgaris, Phaseolus coccineus L. and Glycine max, which have significant inhibition toward pancreatic amylase. The amylase inhibitors’ functions of decreasing in blood glucose were detected by animal experiments on Wistar rats. The rats fed with the extracts of Phaseolus coccineus L. and Glycine max showed the inhibition of glucose increasing at the first hour, while blood glucose concentration after rats fed with Phaseolus vulgaris and Glycine max increase at the third hour, and blood glucose after rats fed with Phaseolus coccineus L. maintains low. Its premier result indicates that the extract from Phaseolus coccineus L. might postpones digestion and has potential to be applied. According to these results, amylase inhibitors are worthy to further analysis.
口琴簧片振動與氣流的影響
本研究主題在測量口琴簧片受到各種氣流因子影響後,所產生音色、音頻等變化之探討。在過去我們認為,一片簧片不論如何吹奏,其發出的頻率皆相同。但是事實上,演奏家控制氣流的強弱、方向、渦流等,便可吹奏出多樣的音頻。探討形狀因子對簧片頻率的影響,如:長度、寬度、厚度對頻率所造成的影響。自製口琴,利用變壓器控制送風機風速。探討氣流因子對簧片主頻之影響,利用各種不同的自製吹嘴,改變風速、角度、渦流…等,找出可能使簧片改變頻率的氣流因素。實驗結果發現改變風速會影響簧片主頻的變化,風速越大,頻率越大,為一條平滑線。但並非一直都會上升,當簧片頻率上升至某一極限,便無法再利用風速使頻率上升。例如實驗四吸音標準狀態下,風速大於8 Kt 後,頻率一直停在429Hz。在外加障礙物時(模擬吹奏舌頭時隆起)和標準狀態(正常零度入射)下頻率比較吹音和吸音有明顯的差異。吹音時,同風速下,其頻率比標準狀態高,發生音升;吸音時,同風速下,其頻率比標準狀態低,發生音降,具應用性。我們發現在頻率改變時,簧片的振動型態會有所不同,所以利用高畫素像機拍攝和電腦相位差算出簧片之曲折點至尾端的距離,發現頻率和簧片之曲折點至尾端的距離成正向關係。如實驗五中頻率從414 至419Hz,簧片的曲折點到振動端距離也明顯變大。我們發現吹嘴和口琴只要稍有一點空隙(大約在0.2cm 左右),便會和完全吻合時有顯著的頻率差距(吻合後大約比有空隙低20Hz 左右),此實驗頻率變化現象和現實壓音頻率變化極為相近。實驗過程中發現,改變簧片吹嘴的吻合程度,吹入口琴的風速相近,但頻率變化卻也有壓音的音頻變化。在實驗三加入各種氣流因子發現入射角度和標準情形差異不明顯,因此推論壓音的頻率變化和風力強度、入射角度關係不大,壓音主要為渦流所造成的現象。簧片振動模式改變,導致簧片振動頻率發生變化,且簧片的自然頻率不變。當壓音產生時,氣流在振動面造成妨礙簧片振動的抗力,但琴格內部同時也給簧片的風壓,使簧片產生一種非自然振動的頻率。The theme of the research is to explore the changes on its timbre and frequency after the harmonica reed is influenced by each kind of air current factor .In the past ,most people think no matter how to play the reed ,the frequency it produced was supposed to be the same. But in fact the frequency will be changeable under different direction, turbulent flow and air intension by the perform. First to explore the basic feature of harmonica reed, for example: The length, the width, thickness cause the influence on the frequency. To make the self-made harmonica, using the transformer control air feeder wind speed. To discussion the influenced caused by air current factors,and use each kind of different self-restraint to boast, change the wind speed, angle, turbulent flow ,in order to discover possible factors the reed causes to change the frequency of the air current factor. The experimental result discovered the change of wind speed can affect the change of basic frequency , the stronger speed cause the bigger frequency, It will be a curve. But it will not be rising continuously, when the reed frequency rise to some limit, it is unable to cause the frequency rise again by using the wind speed. For example experiment four sound absorption standard conditions, after the wind speed is higher than 8 Kt, the frequency continuously stops in 429Hz. To compare obstacle (simulation plays when tongue sticks out) and the standard condition (normal zero degree incidence) , comparison blows the sound agreement sound absorption to have the obvious difference. When blows the sound, under the same wind speed, its frequency is higher than the standard condition, has the sound to rise; When sound absorption, under the same wind speed, its frequency is lower than the standard condition, has the sound to fall. The harmonica terminology for presses the sound, extremely has the application. We discovered when frequency change, the reed vibration condition have differently, therefore use the camera photography and the computer phase different figures out the reed winding point to the end distance, discovered the frequency and the reed winding point relate to end distance is being connected. If tests five medium frequencies from 414 to 419Hz, the reed winding point is away from to the vibration end also obviously changes . The different reed vibration condition cause the frequency to change. Natural frequency is constant. When cause “bending” (the frequency is lower than the standard condition), the airflow make a force keep from reed vibration. But the chamber air pressure still drive reed. therefore cause the reed to give off not natural frequency sound
倒車攝影機影像之變形校正
與傳統的鏡頭比較起來,廣角鏡頭可取得較大範圍的影像,所以廣泛地運用在很多地方,例如倒車攝影機、內視鏡、防盜警眼等,但是其影像會有很大的變形失真,容易造成人類眼睛的錯覺與誤判。本篇研究以倒車攝影機為例,使用了多項式函數來校正其影像的變形與失真,從程式實作的校正結果看來,我們的方法之效果還不錯,相信同樣的模式可用來校正其他使用廣角鏡頭的儀器設備之變形影像。 Compared with the traditional lens, wide-angle lens can make images of larger range, so they are widely used in a lot of places, such as move backward cine-cameras, laparoscopes, and burglarproof eyes. The drawback is that the images distort a lot and may cause the illusion to human eyes and lead to erroneous judgments. This reserch takes the backward cine-camera as example and utilizes multinomial function to correct the deformation and distortion of the image. The results show that the method we use are quite effective and the model can be applied to other equipment with wide-angle lens.
甩毛巾與音爆
在網路上看到甩毛巾、皮鞭的影片,會產生巨大的聲響,查找了資料,我們知道當發聲體超過音速時便會產生音爆。部分文獻提到,毛巾或皮鞭生成音爆原因是來自於角動量守衡理論,我們想利用實驗方法來驗證其正確性,因此利用video point 來分析影片討論手的加速度和毛巾末端質量、長度的關係,並用crocodile physics 做電腦模擬,我們發現毛巾長度與音爆產生無關,這樣和角動量理論模型有所不同。所以我們嘗試利用能量守恆及自由端反射駐波理論來解釋毛巾產生音爆關係,並利用影片分析及crocodile physics 驗證其正確性。We saw the film clippings on the Internet about snapping towels and whips, which made a big noise. After going through related literature, we found out that it is called the sonic boom .Some papers say that the sonic boom results from the Location momentum conservation theory. To prove its accuracy, we used a kind of computer software called Video Point to analyze in the clippings the movement of the hand, understanding the relationship between the mass of the towel end and the length of the towel. We also used another software called Crocodile Physics to simulate the whole process. We discovered that there is no connection between the length of the towel and the sonic boom. It does not conform to the Location momentum conservation theory. We then in turn employed energy conservation theory and the trait of the standing wave (specific wave length) to explain, when we also used Video Point and Crocodile Physics to prove.
研究傳統降火氣食品是否具有抗發炎效果
在炎炎夏日總希望來點可以「降火氣」的食品,依據古籍記載某些中藥材具有降火氣的效應,而中醫所謂的降火氣與西醫的抗發炎反應密切相關。本實驗利用巨噬細胞株受到LPS (Lipopolysaccharide,革蘭氏陰性菌細胞壁表面所含有的脂多醣體)刺激後,會分泌發炎介質的現象,再分別加入各項傳統認為可降火氣(以菊花、薏仁、仙草作為樣品)或上火氣(選用龍眼作為樣品)的中藥食材,來評估中藥材對巨噬細胞分泌發炎介質能力的影響。經由實驗,我們發現市售的『降火氣』中藥食材,在適當的濃度下,確實具有降低IL-6、TNF-α 分泌量的能力,但濃度過高時卻會造成細胞凋亡。另外,傳統以水熬煮的方式比冷凍乾燥取得的樣品有更好的降低IL-6、TNF-α 分泌量的能力。 我們期望以此一系列的實驗,來建立篩選『降火氣』食材的抗發炎效用的研究模式,並在後續實驗中可用以篩選出更多具抗發炎效應的中藥材。In summer, people always consider eating some special things to refresh themselves. According to ancient books, there are some Chinese herbal medicines that were recorded to have the function of cooling us down, which is related to anti-inflammation in the Western. Macrophage cell lines can be stimulated by LPS (Lipopolysaccharide) and secrete proinflammatory mediators. Thus, it is often used to evaluate the anti-inflammatory effects of different herbs. In our experiment, we also use macrophage cell lines to test different anti-inflammatory effects between chrysanthemum, Job’s tears and grass jelly. In addition, some Chinese herbs such as longan that can parch us are also tested in our experiment. In our results, we found these herbs that are available indeed have ability to anti-inflame in appropriate consistency; however, high dose does harm to cells. In addition, the samples that are poached in ancient ways have better ability to show the low dose of IL-6 and TNF-α. Finally, we would set up a model to test the anti-inflammatory ability of different herbs that were said to be able to cool us down, and then we could test more herbs in the future.
台北盆地的熱島效應及其對環境的影響
本研究主要是以台北市中心的氣溫觀測站,以及市區外圍東邊的汐止,南邊的屈尺,以及西邊的山佳等三個氣溫觀測站,從1998 年至2004 年的七年期間的氣溫資料中,來探討台北地區的熱島效應現象。這個研究的結果發現,台北市區與周遭鄰近地區確實會因為熱島效應的影響而產生1~2℃的溫差。這個溫差在白天時不甚明顯,在中午過後,便由台北市中心逐漸向郊區遞減,形成類似同心圓狀的分布。溫差最大值發生在夜晚,使得台北地區晚間宛如一座夜晚增溫的城市,同時夏季的熱島效應又較冬季顯著,氣溫又逐年遞升,造成夏季台北市區的高溫屢創新高,將是未來都市發展的危機。This study is focused on the urban heat island effect of Taipei Basin, northern Taiwan. The hourly temperatures of Taipei meteorological station and three rural sites eastern Hsi-Chih, southern Cyu-Chih and western San-Chia, were compared from 1998 through 2004 to illustrate the temperature differences between city center and surrounding country areas. The results show that a difference of 1~2℃ exists between city center and surrounding country areas, indicating the extent of urban heat island effect in the Taipei Basin. The daily temperature contours show a clear high-temperature bull’s eye at the city center during the midnight, implying the high latent heat trapped by the dense and high rise buildings. This phenomenon is not sharp in the high noon due to the reduction of temperature difference between city center and surrounding country areas. The heat island effect is most prominent in the summer than that of the winter. Along with the increasing temperature-difference trend through years, the summer times often experience record-breaking heat waves and pose great risks for the city development in the future.