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「岸」藏玄機~探討在不同條件下離岸堤的作用
經過實驗的設計探討,我們發現:無設置離岸堤打上岸\r 的波明顯比任何一組有設置離岸堤的波痕高,說明了離岸堤\r 確實能阻擋海浪侵蝕海岸。而離岸堤的設置,在海岸旁的距\r 離、離岸堤間的間距、水中的高度、方位及消波塊的密合度\r 等都會影響到對海浪的阻擋效果。\r 研究結果發現:設置離岸堤較佳的條件是離海岸愈近、\r 離岸堤間距愈小、露出水面愈高、與海岸形成某種夾角、消\r 波塊的密合度越大及增加離岸堤長度都能增加阻擋海浪的成\r 效。但是消波塊使用的個數太多時,將造成成本過高及景觀\r 的破壞,也是值得考量的。\r 建議在未來設置離岸堤時也應將當地海水流動的方向、\r 海水潮汐高度變化等列入考量,以使「離岸堤」發揮最大的\r 功效。
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氣體擴散實驗的進一步探討:自然擴散 v . s 通孔擴散
在國中理化課本第一冊,實驗 6 - 3 :「氣體的擴散」一節中,陳述了氨與氯化氫兩種氣體的自然擴散現象,由於擴散速率不同,故其反應後之產物氯化銨比較靠近氯化氫一邊,但經過多次,多組的實驗所得結果不盡相同,即氯化銨所產生的位置,有的很靠近氯化氫這一端,有的卻較靠近玻璃管中央,其原因如何?是否與實驗所用玻璃管徑有關?長短有關?甚至於是否與鹽酸或氨水的濃度或使用量有關?為了了解這些問題,我們作了以下的實驗。
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奈米複合材料與空氣分子的愛恨情仇-探討奈米碳管對空氣滲透率之影響
本實驗使用聚醚亞醯胺溶液製備基本薄膜,由於玻璃態高分子薄膜過於緻密,一直是高分子薄膜在應用上的一大限制,為了在薄膜上製造缺陷,又不會使薄膜之選擇性降低,因此選擇將酸化之奈米碳管(孔徑10~20nm) 加至聚醚亞醯胺薄膜中。本實驗主要為探討添加不同濃度的酸化奈米碳管對聚醚亞醯胺薄膜的滲透率與選擇率的影響,藉由添加0.5 wt%、1 wt%、1.5 wt%、3 wt%、4 wt%等不同濃度的酸化奈米碳管至15 wt% 的聚醚亞醯胺溶液中,並製作薄膜,測試其基本性質與五種氣體(H2、CO2、O2、N2、CH4)的滲透率及不同空氣分子之間的選擇率。我們總共測試了三種薄膜的性質,分別是表面特性、熱穩定性及結晶型與層間距,薄膜的表面性質,能觀察到奈米碳管在薄膜中製造奈米孔隙結構,增加氣體滲透的孔道,能有效增加氣體的滲透率。增加奈米碳管的量,能有效升高第一階段熱裂解的溫度,雖然熱裂解在本實驗中沒有很大的差異,但是還是可以從熱重分析圖中推測不同量的奈米碳管會影響熱穩定性。在X 光繞射實驗中,添加奈米碳管的薄膜與純聚醚亞醯胺薄膜,在結晶相上都屬非結晶型薄膜,添加了奈米碳管的高分子複合薄膜的層間距明顯增大。在氣體滲透實驗中,我們比較了不同氣體或濃度不同的奈米複合薄膜的氣體滲透率,在不同氣體時,氣體的滲透率會隨著奈米碳管濃度增加有明顯的提升,五種氣體滲透率大致依照H2>CO2>O2>N2>CH4 這個趨勢增減。奈米碳管對1.5%增加到3%或4%的奈米複合薄膜滲透率的影響卻減小,由此可以推斷奈米碳管對空氣滲透率並非無限制的增加,在1.5%以後就漸漸趨近最大值。H2為14.89barrer,CO2 為9.51barrer,O2為6.34barrer,N2為6.48barrer, CH4 為3.75barrer 。本研究總共比較了三組氣體的選擇率,分別是CO2/CH4,O2/N2,H2/CH4,分離率最高的是H2/CH4 的,兩分子的粒徑大小差對分離率有極大影響,差愈大,其分離率也愈高。奈米碳管的量改變並不會使薄膜的氣體選擇率明顯增加或減少,但是加入太多奈米碳管其選擇率會變低。在五片薄膜中,1.5%的薄膜有最好的選擇率,奈米碳管的添加量超過1.5%選擇率就會開始下降。綜合滲透率及選擇率可以分析出,添加1.5%奈米碳管的高分子奈米複合薄膜有較高的滲透率,又不會降低選擇率,在利用上比其他濃度的奈米複合薄膜在有害氣體過濾及空氣的分離回收方面產生更好的效果。;This experiment uses Polyetherimide polymers solution to make basic membranes. Because glassy polymer membranes are too dense for gas permeations, it is one of the limitations in their applications. To increase gas permeability and maintain air selectivity, I made some nanogaps on the surface of the membranes by an acidification multi-wall carbon nanotubes (MWNTs, kinetic diameter 10~20nm) in the PEI membranes. We mainly want to find if it has some influence between the consistency of acidification MWNTs and gas permeability or selectivity. We mixed 0.5wt% 、1wt%、1.5wt%、3wt%、4wt% acidification Carbon nanotube in 15wt% PEI solution, made membranes and tested the character, five kinds of gas permeability (H2、CO2、O2、N2、CH4) and the selectivity between different gases. We have tested the three nature of membranes, including surface characteristic, TGA and XRD. We can see some nanogapes made by carbon nanotube in the membranes. It could availably increase gas permeability. Mixing more carbon nanotube in the membranes could increase the temperature of the first heat-decomposition. Though the heat-decomposition in this experiment didn’t change a lot, we could say that different percent nanotube would affect the membranes’ heat-decomposition. By the experiment of XRD, the membranes with carbon nanotube and the pure PEI membranes attach to amorphous membranes. Nanocomposite’s de-spacing is bigger than pure membranes. In the experiment of air permeability, we compared different kinds of gas or different percent carbon nanotube of nanocomposite if they have some change of permeability. The conclusion is that air permeability increase as the quantity of nanotube increase. The five kinds of permeability the direction:H2>CO2>O2>N2>CH4.The influence of permeability will decrease when the quantity of carbon nanotube increase from 1.5% to 3% or 4%. We can get the conclusion that the increment of gas permeability isn’t limitary. It drifts towards maximal about 1.5%. H2 is 14.89barrer. CO2 is 9.51barrer. O2 is 6.34barrer. N2 is 6.48barrer. CH4 is 3.75 barrer.This experiment totally compared three groups of air selectivity. They ’re CO2/CH4, O2/N2 and H2/CH4. The maximum of selectivity is H2/CH4. The difference of kinetic diameter affects air selectivity a lot. The quantity of nanotube doesn’t associate with the air selectivity, but mixing too much nanotube will decrease air selectivity. The 1.5% nanocomposite has the highest selectivity. If the consistency of the membranes is higher than 1.5%, the air selectivity will decrease. Depend on the gas permeability and the air selectivity, the 1.5% nanocomposite has higher permeability and constant air selectivity. That shows the 1.5% nanocomposite has a better effect on air selectivity and recycling.
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奏湖是個海島,在這兒隨時的可以看到一大批為興趣、為娛樂、甚至為生活的垂釣者。釣魚是一門很大的學問,釣某種魚一定要用某一種餌料都是固定的;海邊垂釣,海蟑螂是用得最普遍的活餌之一。仔細觀察海蟑螂我們發現了很多有趣的問題,例如:(一)海蟑螂的雌雄如何辨別?(二)如何產生下一代?(三)牠們以什麼為食?(四)為什麼在堆滿垃圾的岸邊最多?( 五)為什麼太亮、太乾燥的地方很少?(六) 夏天時數量極多,冬天都跑到那裡去了?是冬眠嗎?(七)在海邊有沒有更省時省力的誘捕方法?(八)有可能在實驗室內繁殖嗎?這一連串的問題引發了我們觀察及做此實驗的興趣!
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對冪級數的收斂圖形、用途及尤拉公式的探討
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My Science Fair project last year tested a local native plant for it’s toxic effects on insects (fruit flies), bacteria, fungi, and viruses. The root of the plant Lomatium dissectum, had been used by the Salish People to control lice and other insect pests in horses and cattle. The root was also used to kill fish, which could then be harvested by women and children. The fish killed in this way were not harmful to eat as long as they were consumed soon afterward. I have found also that fishing with the aid of plant toxins was formerly very common in tropical Africa. \r Lomatium dissectum, grows in dry rocky slopes in conjunction with Sagebrush.\r Many desert plants produce toxic substances that inhibit the growth of competing plants\r nearby. This adaptation is called Allelopathy. In a natural ecosystem, Lomatium does not\r kill fish because it does not grow beside creeks. But this raises the question of whether\r allelopathic plants growing outside their natural ecosystem are having a toxic effect on\r animal life. There are introduced invasive weeds that are allelopathic, such as\r Knapweed,growing near streams. And there are crop plants that are allelopathic – Rye and\r Alfalfa. Do these “natural herbicides” also kill fish? Walnut trees are allelopathic and\r compounds from Walnut kill fish.\r If this effect does go beyond toxicity to other plants, it would be an important\r consideration to environmental guidelines for private land bordering on streams and\r rivers. The B.C. Ministry of Environment notes the importance of shade cover for\r spawning streams. It does not recognize the harmful effects of introduced plants. Yet,\r when we were purchasing supplies for our Koi Pond the pet supply company offered a list\r of “Some of the Worst Plants to Have Around Koi”. We do not know if the introduced\r allelopathic plants are poisoning fish or reducing fish stock by poisoning the food that fish\r need.\r Science Fair rules do not allow any research that is expected to have any negative\r impact on vertebrate animals. Because of this, I have decided to test the effect of\r allelopathic plants on fruit flies (Drosophila). Fruit flies are similar to fish since, during\r larva and pupa forms, they live in direct contact with their culture media. I will also be\r testing the effect of allelopathic plants on Planaria (Turbellaria), an aquatic invertebrate.
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在學校科研營的教材中,有一個題目,其內容相當於:「在一列格子中 放入黑棋與白棋。白棋不可連續放置,而黑棋不受此限,請問共有幾種可能的排列方式?,在此規則下,若將格子推廣為m列n行的棋盤,那又如何呢?我們對此好奇不已。
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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。
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淨化我們喝的水-經濟方便的再生過濾器雛型
近年來由於土地過度開發,經常發生土石流,使得自來水廠進水混濁度太高,過濾設施無法正常運作,本實驗裝置可以利用氣昇?和重力作用,來清洗濾層中殘留物物比重較大的雜質,而且濾砂含自動控制昇?還可以重覆使用,如此便能先處理河川中大量的河水。整個過濾器主要分三個部分;(1)下端進水處理處為高比重的雜質重力沉澱處。(2)圓錐狀的濾層以利於自動清洗時砂層的循環。(3)自動清洗監控部分。濾砂清洗的影響因子為濾層厚度的重力、氣昇?壓力含進水量三者交互作用。濾砂以硬度大的石英砂最佳,濾層高度為25cm,平均進水量0.23升/秒,為最佳處理狀態可獲得原水78.5%的乾淨濾液。Debris flow occurs frequently due to the over-development of watershed recently. The water used as the input of water treatment factory is too turbid to be filtered by the traditional facilities. In this study on experimental apparatus was designed to remove the high density particles or suspended impurities. This apparatus can be used as a pretreatment apparatus of filtering factory. There are three main parts in own apparatus: (1) The precipitation one which is the site for precipitating of high specific gravity impurities (2) Cone shape filter layers which allows for cycle cleaning the sand layers (3) The automatic monitoring apparatus. The effet of water flow rate, air pressure, gravity and the height of filter layer on the performance of the experiment were discussed in this study. Experimental results showed that in the study, the height of filter layers is 25 cm, and the average water volume flow rate is 0.23 liter/sec. The apparatus can achieve a 78.5% leaner filtrate from the original water sample.
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給定一個p∈(0,1),令k0=0,p0在(0,1)間隨機分布,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;若對於所有的n與kn,,則稱p∈I∞。如此區間(0,1)可分解成集合I1,I2,…I∞。
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