全國中小學科展

未代表出國作品

探討茶液成分受光及貯存時間之影響

Tea is the most widely accepted and consumed beverage worldwide due to its characteristic aroma and taste. Recent studies have provided the strong scientific basis for understanding the health promoting effects and cancer preventive actions of tea. The components of tea especial the catechins are varied with the conditions of making tea. To understand and determine the chemical composition of tea is very important. Some investigations of the parameters on the storage and making of tea were carried on in this study. The kinds of tea studied were including black tea, oolong tea, green tea, and instant tea bags. A high performance liquid chromatograph combined with UV detector and mass spectrometer used to analyze the components of tea. The results showed that the composition of tea solution is dependant of the exposure of light. One of the components of tea, (-)-epicatechin methylgallate (ECMG) was oxidized to quino form. The concentrations of (-)-catechin gallate (ECG) decreased and one of new compound (M.W. 442) produced with increasing the storage time. From the results show tea made with cold water is better than that made with hot water. The ingredients in green tea were changed faster than those in fermentative black tea and oolong tea. The components of tea can be kept unchanged for a long time at low temperature. In refrigerator, the time can be extended to overnight. 茶由於其具有特殊的芳香氣味及口味,廣泛地被世人用為飲料,近年來的研究證據顯示茶具有促進身體健康和防癌功效,但茶中成分之變化,尤其兒茶素隨茶的種類、茶沖泡保存方式及置放時間而有所不同,因此對於茶中成分及沖泡方式的認知是一門重要的課題。 本實驗主要是探討茶沖泡時間及貯存條件,對於茶液所含兒茶素變化的影響,探討的茶包含紅茶、烏龍茶、綠茶及其茶包。並使用質譜儀及高效能液相層析質譜儀配備紫外光偵測器分析茶液中之成分,實驗結果顯示成分變化速率以未發酵的綠茶較發酵的紅茶和烏龍茶快;低溫儲存時,亦可延緩茶液成分的變化,例如加蓋並存放於冰箱,則茶置放至隔夜其成分均未改變;同時結果顯示成分產生變化者,主要為兒茶素氧化,如將多酚類氫氧基經氧化變成?(quino) ,其次為斷裂再產生聚合其中綠茶以不照光變化較大。本研究並經實驗發現如果以冷開水沖泡綠茶20~30分鐘,咖啡因的溶出量雖略多於沖泡2分鐘的熱茶,但各種兒茶素的溶出量卻遠高之,尤其置放至隔夜茶液成分仍無氧化現象。

以阻抗匹配調整太陽能最大功率輸出之研究

In recent years, the price of the oil keeps rising continuously. As a result, the prices of the commodities are rising, too. But what does this mean? This situation stands for the resources on are becoming more and more valuable. A few months ago, I read a Weekly Business Magazine and a Scientist Magazine. They both pointed out that the resources such as oil would disappear after fifty years, and that was a horrible phenomenon. Since almost everything in our modern lives are related to oil, like automobile, motorcycle and air plane. They all need oil for its ingredient. Even plastic bag plays a part in the products of it. I really cannot imagine what it would be like if we don’t have oil after fifty years. Owing to the green house effect is becoming more severe, there are many substitution resources found, such as hydraulic power, wind power and solar energy…etc. What we’re discussing in our topic is how to enhance the power of solar energy, because for now, we all know that the solar module is very expensive and it cost a great deal of money just only one square meter, but the price of module converted from sunlight or heat energy can’t be higher. Therefore, the work is mainly to design and carry out a solar max power point track. 近年來,油價不斷的上漲,連帶著民生的物價漲幅也是越來越可觀,但…這意味著什麼 呢??這所代表的是地球上的資源可以說是越來越珍貴了,前陣子曾經看過商業週刊、科學人 雜誌…他們紛紛所指石油這種能源可能在五十年後就消失殆盡,這個可是非常可怕的結果。 鑑於溫室效應愈趨嚴重,許多的替代能源紛紛出籠,像是風力、水力和太陽能等等。我們這 次的主題是在討論如何提高太陽能效率,現在的太陽能模組我們都曉得非常的昂貴,但是由 太陽轉化成電能的效率卻是低的可以。所以本作品主要目的在於設計與實現一個太陽能最大 功率追蹤器。

淘氣精靈(ELVES)高空放電現象性質探討

ELVES (Emissions of Light and VLF perturbation due to EMP Sources) is a transient luminous phenomenon of ionosphere induced by the electromagnetic pulse of lightning. In this report, we use the data of ISUAL science payload of FORMOSAT-2 to investigate the luminosities and the stepped-leader signals of the different kinds of ELVES.淘氣精靈全名Emissions of Light and VLF perturbation due to EMP Sources簡稱ELVES,為閃電的電磁脈衝波引發電離層短暫發光的現象,本研究是分析福爾摩沙衛星二號上科學酬載ISUAL的光度資料,以探討淘氣精靈類型與光度訊號強度以及閃電前導訊號的關係。

月相變化對極地天氣系統的影響及其引發高緯度天氣變化之探討

本研究比較2003~2005 年,冬季及夏季西經168 度之「海平面溫度異常」對「緯度」的分布圖,結果呈現在赤道附近的變動較小,在高緯度地區的變動較大,為更精確的描述此變動,將每日高緯度地區的變動以「標準差」及「最大振幅」數量化,發現在南、北半球不論2003、2004或2005 年,每7~12 天南、北半球的「冬夏季海平面溫度異常」的變動變大,上述變化在北半球較為明顯,在南半球較不規則。 與2005 年冬季1 月31 日~3月17 日的北半球地面天氣圖進行分析比對發現,溫度的變動和極地天氣系統的形成關係密切,推測原因和冬季時極地為永夜,地面空氣溫度受到兩個跟月球有關的熱源影響較大,其一為海流和極地間每日有接近2 次的潮汐交替運動,其二為月球反射日光後投射到極地時,極地大規模的冰對月光的反照,對極地微弱的加熱作用。 針對2005 年6 月1 日~7月22 日之地面天氣圖作分析,結果發現夏季緯度的溫度變異和高中低緯度天氣系統的改變關係密切,推測此時和月球對海水的吸引使地表(特別在海陸邊界)的溫度,週期性的重新分配,或對大氣應也會造成週期性的質量分配有關。 以農曆為主重製溫度的變動圖並進行比對發現,無論2003、2004或2005 年,在月相為朔及望時常出現低值。此分析結果顯示,接近朔望時,高緯度海平面溫度有較穩定且變動較小的情形。而從天氣圖、農曆標準差綜合,所得結論為地月運動應和地球上高緯度天氣系統存在某種相關性。 ;Our topic is about how the moon phase variation influences the high-latitude weather system. This study analyzes the sea surface temperature anomalies (SSTAs), along 168°W in winters and summers from 2003 to 2005. The results show that the SSTAs varied relatively small around the equator and relatively large in high-latitude regions. So we next analyze the high-latitude SSTAs by the standard deviations, the maximum amplitudes, and the north surface weather graphs. After analyzing, the result shows that the SSTAs rise for every 7 to 12 days. Moreover, they relate to the winter high-latitude weather system very much while relating to the summer medium-and-low latitude weather system a lot. We think it’s because in winter eternal night, the sunlight won’t shine on the arctic zone easily. Other heat sources may become important: (1) the tidal movements between the ocean and the arctic zone. (2) The heat radiation of the moonlight and the moonlight reflection by the polar ice shields. But in summer, the moonlight effect becomes extremely small. The tidal force becomes the bigger influence factor: (1) the tidal attraction may distribute the temperature of the border between seas and land periodically. (2) It may cause the periodic atmosphere mass distribution. Additionally, after repeating the same experiment according to the Chinese lunar calendar, we found near full-moon and new-moon time, the SSTAs are more stable. Probably because of without the moonlight, the movements of rip-tides occur and help stabilize the polar weather conditions. In conclusion, the relative movement of the moon to Earth is likely providing a crucial heat source which will affect the high-latitude climate, and the heat source size probably influences the weather system cycle.

美麗的陷阱 - 探討線蟲捕捉菌之捕蟲機制及應用

線蟲為植物發生病蟲害感染的病源之一,而台灣的松樹,目前正面臨著松材線蟲入侵的危機。從文獻的探討中,發現線蟲有其自然界的天敵 - 線蟲捕捉菌。本實驗著重在探討線蟲捕捉菌特殊的捕捉機制。當線蟲捕捉菌附近出現線蟲時,會展生誘引線蟲的物質,並設計了一步步的實驗,去探討此誘引物質的捕蟲效能及其成分。現在,已經發現此誘引物質為一揮發性氣體。往後將會設法增加其誘引氣體的產量,並使用氣相層析儀分析之。最後希望可以將此物質應用到微生物防治上,期望能解決台灣松樹被線蟲感染的問題。 In Taiwan, all of the pine trees have one common problem - nematodes, which causes diseases in plants. And this experiment focuses on the nematodes’ natural enemy - nematophagous fungi and its “peculiarly caused mechanism.” When nematodes appear near nematophagous fungi, the latter will produce some substance to tempt the former. To investigate this alluring substance, a series of experiments are done and systematic steps are taken. The first finding is that this substance is a volatility gas. Later in this research, measures will be taken to make “rematophagous fungi” produce more of this gas. And “gas chromatograph” will be used to analyze this gas in the future. Finally, the possibility of applying this substance to the defensive measure of microbiology will be discussed.

熱線式渦流流量計

流量計在實驗室與工業領域裡是重要的儀器,如今已經有數十種依不同物理原理而發展出來的型式,可以配合多變的環境需求與測量條件而使用。然而,各種流量計所適用的範圍備受侷限。本研究主要目的在發展一種熱線式的渦流流量計,供給氣體之流量量測之用。透過自行製作儀器與設備:熱線測速儀(包括探針、探棒及電子處理器)和渦旋產生器(管道中含一三角形截面之鈍體,當流體通過時,在後方尾流產生週期性渦旋逸放)。由於熱線測速儀擁有偵測流體運動時高頻動態變化的能力(約為20000 Hz 以內),因此結合熱線測速儀與渦旋產生器,經適當的設計與調校,可以測得在不同流體流速時渦旋產生器的三角截面鈍體後方渦旋逸放的頻率。由於渦旋產生器的截面面積為固定值,因此可以從而計算出流量與渦旋逸放頻率的關係。經由嚴格的校準與驗證步驟,本研究的結果顯示自製的熱線測速儀擁有極佳的渦旋頻率偵測能力,所量測到的校準曲線顯示渦旋產生器的三角形截面柱所產生的渦旋逸放頻率與流量成線性關係。為了降低誤差,建議在0 ~ 40 CMM 之量測範圍內分成三條方程式來代表不同範圍內的校準曲線,最大誤差僅在5%以下。若需使用在不同的流量範圍時,僅需改變渦流產生器和幾何尺寸,以使渦旋逸放頻率適合於熱線測速儀的動態響應範圍即可。倘若商品化之後,可以實際應用於風扇流量量測、引擎進氣埠流量的測量等等應用。熱線測速儀本身也可作為風速計,適用於各種場合之風速量測。Flow meter is a instrument that is vital to the laboratory as well as the industrial related field. Based on different physical principles, tens of models that work in harmony with the diverse environmental demands and measurement conditions are developed to date. However, the application of varied flow meters is still under severe restriction. The purpose of this study is to develop a hot-wire type of vortex shedding flow meter for the use of flow rate measurement. Through the home-made apparatus and device, the hot-wire anemometer (includes probe, stem and electronic processor) and the vortex generator. (duct that contains triangle’s section of the bluff body. When fluid passes through, the wake behind produces periodical vortex shedding.) The ability of hot-wire anemometer when it detects the fluid moving changes of high-frequent movement is within 2000Hz, after appropriate design and adjustment, the combination of hot-wire anemometer and vortex generator may investigate the frequency of different flow rate that generated from the vortex shedding behind the bluff body of triangle section. The section area of vortex generator is constant value, thus it can calculate the relationship of flow rate and the frequency of vortex shedding. By means of strict calibration and test procedure, the results reveal that home-made hot-wire anemometer has excellent ability to detect the frequency of vortex shedding. The calibration curve indicates a linear relationship between the frequency of vortex shedding and flow rate. In order to reduce inaccuracy, it is suggested to classify three formulas to represent the flow rate that ranges from 0 ~ 40 CMM. The greatest inaccuracy is under 5%. When applied to different flow rate range, it only has to change the size of vortex generator only if the response frequency of hot-wire anemometer suit for the range of frequency of vortex generator. After commercialization, it can be applied to measure the flow rate of fans, flow rate of intake valve of engine, etc. Hot-wire anemometer also served as anemometer, which can be applied to wind velocity measurement in any situation.

翻轉「膜」力

The starting point of this experiment is to study the structure of soap-film. By changing the height of the triangular prisms, cuboids and pentagonal prisms, I observed the patterns set by the soap within the frameworks. It is surprised that when the proportion of prism is in a specific range, the phase in the middle of the structure will overturn 90 degree and then transmitted into another kind of balance pattern. I named this process “phase transition”. According to the experiment ,we can conclude the change of film patterns within variable prisms are all applied to this regular cycle:: We know the soap films are forever attempting to minimize their energy. It stands to reason that surface tension tend to set up the film in its minimal surface. From the point of Mathematic, each structure should have only one single balance pattern, which is set up on the base of Fermat point and this pattern should stand to the minimize of it’s energy. However, we discovered that in some specific cases, one structure can allowed two kinds of balance films-patterns to exist. In these cases, any small vibration can cause the happening of “phase transition”. To sum up, I presume some structures have two different types of balance film-patterns: one of which stands to the local minimum (in this condition the pattern’s surface area isn’t the smallest); the other stands to the absolute minimum (in this condition the pattern’s surface area is the smallest). There is an energy valley separate local minimum from absolute minimum. The second pattern (local minimum) will appear when the structure is blocked from attaining its absolute minimum, but surface intention is not powerful enough to support the film jumping over the energy valley. In this condition, if we works on the structure (such as blowing), which would provide the film of energy to cross the valley, and then phase transition take place. Vice versa, we can also force the film to jump from absolute minimum to local minimum and phase transition will occur as well. In a word, phase transition can happen in each two way, which connects the two types of balance pattern. This report lays stress to find out the condition of phase transition. We also analyze the structure of soap-film by its included angles and surface area in hope to go deep into the science of soap-film. 我們實驗的出發點在於研究泡膜的立體結構。藉由改變正立方柱的高,觀察其平衡薄膜形式,意外的發現當正立方柱的邊長比在某個範圍時,泡膜結構中央會瞬間90 度翻轉,形成另一種平衡型式,我們將這個過程命名為面轉變(Phase Transition)。為了進一步了解面轉變發生的相關因素,我們設計了一連串的實驗,針對正三角柱、正四角柱、正五角柱、正六角柱發生面轉變的時機和條件分析討論。此外,我們還分析了泡膜結構中膜與膜夾角的特性、最小表面積和表面能之間的相關性,對於泡膜的立體結構做了一系列深入的探討。

台灣稀有水生植物蓴菜生長型態構造觀察成分分析研究

本研究針對台灣產水生植物,蓴菜之構造與生長環境、蓴菜對腸胃道常見致病細菌之抑菌效果以及主要成分暨化合物分析。由本研究結果得知,崙埤湖內之稀有浮葉型水生植物蓴菜,其生長環境為無汙染之乾淨偏酸性水源,最適合生長之生深為50-160 ㎝;水溫則為22-25℃;而蓴菜之地下根莖對表皮金黃葡萄球菌(Staphylococcus aureus)具有輕度之抑菌效果,經由分離純化得知為BS-1:沒食子酸(Gallic acid);另外,由蓴菜之葉片分離出十種成分分別為BS-2 (Kaempferol-7-O-Glucosids)、BS-3 (Quercetin-7-O-glucosids)、BS-4(5,8,4’-Trihydroxyflavone-7-O-glucosids)、BS-5 (3,5,8,3’4’-Pentahydroxy flavone)、BS-6(Vitamin E: d-Tocopherol)、BS-7 (Glyceride)、BS-8 (Phenolic A)、BS-9(Quercetin)、BS-10(Kaempferol)、BS-11(Phenolic B)。其中發現BS-8 對神經膠腫瘤細胞株有18.42%之抑癌效果,另外,BS-2、BS-3、BS-5、BS-10、BS-11 等成分,呈現良好之美白作用。This investigation is to analyze Brasenia schreberi Gmel., a native rare floating water plant in Taiwan, focusing on the plant’ s structure, its growth environment and, most importantly, the effect of chemical compounds it produces on restraining the common pathogenic bacteria in human stomach. The result indicates that the most suitable growth environment for Brasenia schreberi Gmel. is in slightly acid, pollution-free water such as that in the lake Lung Pi in northern Taiwan. The ideal water depth for its growth is 50-160 cm, and the water temperature is 22-25°C. The impractical BS-1 (Gallic acid) extracted from the izome of Brasenia schreberi Gmel. by separation and purification has a light effect on restraining Staphylococcus aureus, a bacteria in the stomach. From the epidermis of the blade of Brasenia schreberi Gmel., ten other ingredients are also isolated, including BS-2 (Kaempferol-7-O-glucosids), BS-3 (Quercetin-7-O-glucosids), BS-4 (5,8,4’-Trihydroxyflavone-7-O-glucosids), BS-5 (3,5,8,3’,4’-Pentahydroxyflavone), BS-6 (Vitamin E: d-Tocopherol ), BS-7 ( Glyceride ), BS-8 (Phenolic A ), BS-9 (Quercetin), BS-10 (Kaempferol),and BS-11 (Phenolic B). BS-8 is found to resist cancer C6 ( Glioma ) by 18.42%, while BS-2,BS-3, BS-5, BS-10, and BS-11 show an outstanding effect on skin-whitening.

太陽能熱動力發電與效益的改進方法

在綠色能源中太陽能的利用充滿了無限的機會,其中利用太陽熱能發電的太陽能煙囪觀念有很大的潛力。在本研究中,我們以實驗的方法討論煙囪高度、入風口大小、管型等因素對solar chimney 效益的影響,發現就原先的觀念設計中,有相當大的改進空間。整體實驗而言,所改變的各項變數中,以管型之改變有最大的改進效益。就同長度直管與漸擴管而言,漸擴管在風速上有明顯改進效果,且以流速與截面積換算成效率,較原直管設計之效率高出約20 倍,因此推測漸擴管應用在現行之solar chimney 以改進效能是極有可行性的。研究中也發現煙囪管壁的熱傳導也會影響氣體的總體流動,使效率降低。相信此實驗之數據對日後嘗試對solar chimney 進行改進的研究者有相當之參考價值。Solar energy has a great market potential among many clean energies. The new solar chimney concept using solar thermal power in power generation may have a bright future. Experimental work was performed to study the energy conversion characteristics of a solar chimney. The air moving capability and the influences of chimney height, the shape of chimney and air entrance dimension were studied. It was found that there is a great room to improve the current solar chimney design and thus the efficiency. Overall speaking, the chimney pipe geometry may have the most significant impact on the improvement of performance. A diverged pipe configuration can induce nearly 20 times more flow than a traditional straight pipe. Another finding is the heat transfer effect on the chimney pipe may have the effect in reducing the flow. It is believed that the present study0 is valuable for those people in designing a future solar chimney.

培地茅根系碎形維度及抗拉力

本研究首先確認培地茅根系具有碎形之基本特性,再進一步以方格覆蓋法計算之碎形維度來分析培地茅根系在不同時間及環境因素下的生長。主要探討碎形維度與抓地力之關係,並設計以實際根系模型來加以模擬,並發展出一可描述抓地力與碎形維度及深度關係的方程式。我們的結論為:(1) 經由方格覆蓋法之計算,培地茅此種植物,不管是整個根系或單枝根,均具有碎形基本特性,適合進一步實驗研究。(2) 碎形維度會隨著培地茅生長時間增長而增加,並且在自然光照及30℃左右會有較大值,而種植於土壤中根系發展較廣,其碎形維度比種植於沙耕中來的高。(3) 實驗結果顯示,抓地力受碎形維度及根系深度兩因素影響,而培地茅根系對土壤有較強的抓地力,推測是因為兩者根系皆又深又長,土中培地茅根碎形維度較大,接觸面積較廣,而又進一步以矽膠模型做實驗驗證。(4) 矽膠模型之目的在於減少難控制之自然變因,實驗之前,測量了根系模型與洋菜凍之基本性質,實驗結果顯示抓地力與碎形維度及根系深度皆呈正向關係,可用數學方程式加以描述。This project is mainly a research into the fractal dimension of the vetiver root system. First, we confirm the vetiver root system has the basic fractal structure by checking its self-similarity, then using box-counting method to calculate fractal dimension. We begin with a fundamental investigation into the relation between different time and environmental factors and fractal dimension. Then we move to our main point: the relation between fractal dimension and its pull-out resistance. In the next step, we make a fundamental silicon model, simulating the vetiver root system, to continue our experiments. In the end, we develop a formula that can describe the relation between its pull-out resistance, roots depth and fractal dimension. Here are our conclusions: (1) After using box-counting method to calculate fractal dimension, we discover that not only the whole vetiver root system but also a single vetiver root has the basic fractal structure. (2) Fractal dimension increases when time goes on. Also the value of fractal dimension is larger in natural sunlight and the temperature at about 30℃.The vetiver root system grows more widely in soil than those in sand. That’s why it has larger fractal dimension. (3) Data shows that its pull-out resistance is influenced by both fractal dimension and the depth of the roots. The vetiver roots, in the meantime, show greater pull-out resistance than some other plants. Thus we draw the assumption that the vetiver root system grows deep and wide, and in natural soil its fractural dimension is greater and reaches greater area. Therefore, a silicon model is constructed to further confirm the findings of the experiment.(4) The design of the silicon model is to reduce the uncontrollable variables in nature. Before starting the experiment, we measured some basic characteristics of the silicon model, including density and angle of repose. Furthermore, the experiment demonstrates that pull-out resistance and fractural dimension have a commensurate mutual relation: the stronger the pull-out resistance, the wider the fractural dimension and the deeper the root system. Thus we derive a math formula to describe this relation.