全國中小學科展

未代表出國作品

垂直水柱的成節機制探討

本研究欲探討垂直水柱遇障礙物成節的形成機制。以數位照相機、光電計時器等進行觀測。 實驗結果如下: (一)因往返水柱波速不同,而且節無波腹大幅振動現象,故節不是駐波現象。 (二)細針插入水柱表面時,當針上方超過某長度後,針下方產生V字形震波。但不論針相對水柱的速度是否超過波速,針上方都有節,故不是震波所產生的現象。 (三)根據水波槽模擬實驗,不論木條是否超過波速,木條前方均產生波紋。木條前方的水受到木條推動,往前方加速,因此顯現出波紋了。 我們認為,在水柱中所看到的節,不是震波或駐波,而是相對於木條往前傳遞的波。波源是撞擊物,改變了水柱表面的壓力,而成為波源,水柱的水因受撞擊,某個範圍內流速會小於波速,使得撞擊物前方存在波紋。This experiment uses digital camera and photoelectric timer to discuss the mechanism of causing spouts to form nodes on its surface. Because the downward wave velocity of the spout is different from that upwardand there are no significant vibrations of antinodes, standing waves are not the mechanism of causing nodes. In the experiment of inserting a needle into the spout, we found out that while the needle was inserted above a certain length of the spout, v shaped bow waves emerged. However, no matter the velocity of the needle related to the spout is over the wave velocity, there are always nodes above the needle. Therefore, bow waves are not the mechanism of causing nodes. According to the ripple tank simulating experiment, no matter whether the speed of the wooden stick is faster than the wave velocity or not, there are always waves forming in front of the wooden stick. The wooden stick pushes water in front of it and causes the water to accelerate forward. Therefore, waves appear. We think that the nodes we see on spouts are neither standing waves nor bow waves. The nodes are rather caused by the relatively moving wooden stick. The object, which impacted the spout (wooden stick), changed the pressure of the spout’s surface and became the source of wave. Because of the impact, the velocity of the water current of a certain area became slower than the wave velocity and causes nodes forming on the surface of the spout.

碳黑受閃光產生爆鳴聲之研究

紙杯底部用蠟燭燻出碳黑,經數位相機閃光拍攝後會聽到爆鳴聲。探討的結果為爆鳴聲是由相機的閃光與碳黑之間的互動所引起,甚且到冒煙程度。\r 探討結果得到爆鳴聲大小會受電場、溼度的影響而且碳黑量愈多,電子傳遞路徑會縮短、導電性則增高,且與產生的電量接近線性關係。\r 發現波長較短的可見光可形成較多的電荷;若照度大、受照射面積大或碳黑的粒徑小,這些會產生較多的電量。\r 經由電顯及AFM圖可知去漬油、蠟燭、瓦斯、95汽油、酒精燃燒後產生的碳黑,大小範圍都是在30nm~100nm範圍內。將蠟燭碳黑接受不同次數的閃光後,看出表面碳粒會變成灰燼。

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.

利用滾動實驗測量摩擦係數

A cylinder rolling on an inclined plane and a sphere on grooved tracks are discussed in details.Using elementary mechanics, the formulas are derived for the time interval (t) and the final speed (vas a function of release height (h). (1) A cylinder is rolling down an inclined plane. The speed and time of the center of mass ofthe cylinder which changed with position (x) are recorded by a motion sensor. We can get theplots of v vs. √x and t vs. √ x, and find that the acceleration of the center of mass of thecylinder is constant, whether the cylinder is in rolling or a combination of rolling and slipping. (2) A sphere is rolling down an inclined grooved track. The final speed at the bottom of thetrack can be calculated from the physics of projection motion after the sphere leaves the track to thefloor. The time t for the sphere starting from rest to the bottom can be recorded by using photogate detectors. From the v-√h and t-1/√h graphs, μs between the sphere and track can be obtained. (3) When a sphere is released from the vertical height h of a cycloidal slide, the time tof pure rolling is the same independent of release position. But, when the sphere moves at a combination of rolling and slipping, the time t' will be different from t. We measure t and t' with photogate detectors and get the plot of t vs. h. The value ofμs can be calculated from the t - h graph. 圓柱或鋼珠從斜面或有槽曲面形成的軌道上滾下時,利用基本力學,可推導出時間 (t) 、速率 (v) 隨高度改變的函數關係。 (1) 利用運動感應器記錄圓柱由斜面上滾下時,圓柱質量中心的速度及運動時間隨位置 (x) 的變化,可繪出 v 對√ x 及 t 對 √x關係圖,由v-√x 及 t-√ x圖可知不論圓柱純滾動或滾動兼滑動,其質心均等加速度運動。 (2) 鋼珠由有槽斜板滾下時,到達底端的速率可由從底端至地面的拋體運動算出,而其時間t則可利用光電計時器直接記錄,利用 v-√h 圖及 t-1/√ h 圖可求出鋼珠和軌道的靜摩擦係數 μs。 (3) 鋼珠從旋輪線上方純滾動至底端時,所經歷的時間 (t) 和釋放高度無關,但是當鋼珠滾動兼滑動時,所經歷時間 t' 會改變,利用光電計時器量出 t 及 t'並作圖,利用 t-h 圖可出 μs。

“氮”憑本事-土壤中單棲固氮細菌族群比例及親緣關係探討

Azotobacteraceae 為一單棲固氮菌科,包含Azotobacter 與Azomonas 兩菌屬,在農業上可用來改善缺氮的貧瘠土壤。在分離土壤中的Azotobacteraceae 時,發現非單棲固氮菌與單棲固氮菌間可能具有共生的情形。我們利用優勢培養(缺氮)的方法篩選土壤中的Azotobacteraceae,將優勢培養後所生成的菌落稀釋104~106倍後,能有效分離Azotobacter 與Azomonas,然而低於此稀釋倍率則會形成混合菌落,其中可同時發現單棲固氮菌與非單棲固氮菌存在,推測某些非固氮菌在優勢培養過程中可能可從單棲固氮菌獲得氮源,與之共生。此外亦從菌種形態的差異並配合顯微螢光雜合技術(fluorescence in situ hybridization, FISH)、分子遺傳標記(16S-rDNA)等方式,分析土壤中的Azotobacteraceae,探討單棲固氮菌及其他非單棲固氮菌在培養基上的生長情形、比例及親緣關係。The family Azotobacteraceace is group of free-living nitrogen-fixing bacteria that is found in soil. Two genera are within this family: Azotobacter and Azomonas. Agriculturally, it is often used to improve fertility for nitrogen deficient barren lands. We analyze the Azotobacteraceace according to molecular biology and traditional taxonomy. We used an enrichment procedure to culture the bacteria, and diluted it repeatedly. We found it most suitable to dilute it 104~106 times to best separate Azotobacter from Azomonas. If the concentration were to be higher than this, mixed flora containing many different bacteria species would be found. Moreover, we noticed that non nitrogen-fixing bacteria, symbiotic nitrogen-fixing bacteria, and free-living nitrogen-fixing bacteria would form a single colony on a nitrogen-deprived medium. This implies that a symbiotic relationship may exist between nitrogen-fixing bacteria and non nitrogen-fixing bacteria. We also discuss the growing situation, the group proportion, and the relationships between free-living nixtron fixing bacteria and other bacteria by morphology, fluorescence in situ hybridization (FISH), and molecular biology.

核醣核酸蛋白粒之K 蛋白基因表現及功能之研究

核糖核酸蛋白粒之K 蛋白具有多種功能,可參與在基因轉錄和蛋白質轉譯等過程。我們發現\r 一新奇的cDNA 較已報告的K 蛋白cDNA 少了72 個核?酸,分別命名為S 形與L 形。由基因\r 組DNA 的分析,S 形可能是經由替代剪接少了第8 個exon 所形成。以西方墨點法分析細胞中\r 的K 蛋白,亦證明有S 形存在,其表現量較少且多存在於細胞核中。為了探究兩種K 蛋白等\r 形的表現和功能,我們以PCR 偵測K 蛋白在不同組織與細胞株和人類乳腺腫瘤組織中的RNA\r 表現,結果顯示主要以L 形為主;我們並將S 形與L 形K 蛋白分別轉染至人類乳癌細胞株MCF7\r 中,以抗生素篩選出穩定表現K 蛋白之細胞株,生長速率分析顯示表現S 形之細胞株生長速\r 率較慢,其分子機轉仍有待研究。另外在比對K 蛋白之基因組DNA 時,除了在第九對色體\r 上有完整之K 蛋白基因組DNA,我們亦發現在第2、3、5 及11 對染色體上有類似K 蛋白基\r 因的序列,以cDNA 的形式存在,這些DNA 序列是否可以表現RNA 及其意義為何,目前尚\r 不清楚。Heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a multifunctional protein known to be\r involved in the regulation of transcription, translation, nuclear transport and signal transduction. We\r have identified an alternative splicing transcript of hnRNP K lacking exon 8. This novel isoform\r (named S form compares to L form of full-length hnRNP K) encodes a protein that is 24 amino acids\r depletion between RNA binding KH1 and KH2 domain. To explore the functional roles of both isoforms,\r we detect their expression in several tissues (including liver, lung, kidney and heart), cell lines (MCF7,\r 293T, HeLa, NIH3T3, WEHI, P388D1) and specimens of human mammary gland tumor by RT- PCR.\r The results showed that L form was expressed in all samples, whereas S form was only expressed in cell\r lines. Using Western blotting analysis, we found that L form existed in both cytosol and nuclear\r fractions, and little amount of S form was detected in the nuclear extract. Furthermore, we construct the\r MCF7 cell lines that stably expressed S form or L form hnRNP K. Growth rate analysis indicates that\r the overexpression of S form of hnRNP K could decrease cell growth rate. The molecular mechanisms\r of growth inhibition by S form hnRNP K are to be further investigated. On the other hand, when we\r blast the human genomic genebank, we found except the chromosome 9 containing complete hnRNP K\r genomic DNA, there are near complete hnRNP K cDNA sequence appears in chromosome 2, 3, 5, and 11.\r The meaning of these sequences is unclear.

小小細菌立大功-油類生物復育模式的探討

20 世紀初,石油的量產造就了人類文明前所未有的繁榮,然而由於運送、廢棄處理等因素,使得油類污染成為環境保護的重大議題。本實驗中,我們的研究主題為在受油污染的土壤中純化並鑑定出可分解油類之土壤菌和綠膿桿菌對可分解油類之土壤菌與這群土壤菌彼此之間的交互關係,藉此了解它們間的互動對環境生物復育的影響。我們由受油類污染的行道樹土壤中分離了約12 種的土壤菌,其中我們得到3 種對油類分解效果效果極佳的非綠膿桿菌(暫時命名為P7A、P7C、P7D)。經過菌種鑑定發現P7A、P7C、P7D 均為格蘭氏陽性菌。為了解這群可分解油類之土壤菌間的互動關係,我們針對分解效果最佳的P7A、P7C、P7D 作為研究對象,將菌落接種至含有鹽類與機油的液體培養基中震盪培養,並每隔一定時間測量其O.D 值。結果發現P7A、P7C、P7D 間的互動會導致其在以機油為單一碳源的培養液中之生長速度的改變,因此在行環境生物復育時須注意土壤菌間交互關係對其分解污染物速率的影響。此外我們由受油類污染的行道樹土壤中亦分離出了一些綠膿桿菌,因文獻指出,綠膿桿菌所分泌的綠膿素降低受油污染土壤中土壤微生物相的多樣性;因此,我們將由行道樹土壤中純化出的綠膿桿菌T3 與可分解油類P7A、P7C、P7D 進行交互作用觀察,發現T3 會侵占P7A、P7C、P7D 的既有菌落區,而平板培養基亦可清楚看出和T3 交接的P7A、P7C、P7D 菌落區寬度有明顯降低,因此我們認為T3 可抑制或殺死P7A、P7C、P7D,可得知綠膿桿菌會對可分解油類之土壤菌產生抑制或競爭關係。In early 20th century, the exploitation of petroleum transformed human civilization into a tremendously prosper stage. Because of the transportation and disposition of petroleum, the oil pollution has become a important issue in environmental protection. Besides, Chloropseudomonas spp. which can survive in many different environments and decompose lots of organic compounds. In this study, we want to find the bacteria which can utilize oil from machine oil-contaminated soil, investigating the interaction relations between Chloropseudomonas spp. and these oil-degrading soil bacteria. First, we classified these oil-degrading bacteria by the book called“Bergey’s Manual of Systematic Bacteriology.”We find three species of oil-degrading bacteria (P7A、 P7C、P7D) which are all grams-positive bacillus, possibly belonged to Aureobactreium、Curtobacterium、Cellulomonas、Oerskovia、Brochothrix、 Caryophanon. Second, in the study of the relationship between Chloropseudomonas spp. and the oil degrading soil bacteria, we found that Chloropseudomonas spp can considerably inhabit the growth of oil-degrading bacteria. Besides, there are also a great variety of interaction between three species of the oil-degrading bacteria. According to the result , the interaction might considerably affect the efficiency of oil bioremediation. Due to our analysis, we suggest that it is necessary to pay more attention to the interaction between bacteria when undertaking oil bioremediation.

乳酸桿菌及啤酒酵母之相互作用及其代謝產物對Clostridium difficile 生長之影響

市面上可以看到多種品牌紛紛推出了以“啤酒酵母”作為號召的乳製品,標榜健康取向\r 的“啤酒酵母優酪乳”也是其中的一件,我們蒐集了關於啤酒酵母以及乳酸桿菌的文獻,打\r 算研究之間的關係,乳酸菌屬於益生菌,主要的用途是製作優酪乳,可以協助維持體內正常\r 的腸道菌相,降低血清膽固醇以及預防骨質疏鬆症(Rolfe, 2000);啤酒酵母最主要的用途為\r 啤酒的製作,具有解決失眠、消除疲勞、改善痢疾的功效。外國的克芙爾(kefir)也是屬於含\r 有乳酸桿菌及酵母菌菌相的食品,而且也對健康有益。因此我們提出了一個問題﹕啤酒酵母\r 與乳酸桿菌的代謝產物是否有著互利的功效呢?在拋出第一個問號後我們繼續尋找資料以\r 及著手我們的實驗。在文獻中(Gaon et al.,2003;Corthier et al.,1992,1986)也曾經提及啤酒酵\r 母與乳酸桿菌對於Clostridium difficile 所引起的偽膜性腸炎的關係,所以使我們又想問兩個\r 問題:究竟Ampicillin 對於乳酸桿菌、酵母菌、C. difficile 的影響有多大?而乳酸桿菌及酵\r 母菌對於C. difficile 的影響又是什麼?

這不是群體防禦─反駁行為學家對魚群行為的高估

This study is to discuss the reason that interfere the fish schooling behavior " adult fish surround the young fish ". I use mathematic simulation, to observe the result when the fishes are stimulated, due to the body size , the speed of swimming , the difference of sensitivity will make different reaction. We predict the motion dots of fish when the hunter appears on the block paper, then analyzes the motion of adult fish and young fish in dot to determine if the result remind "adult fish surround the young fish "structure. The conclusion shown that natural reaction physiologically on fish will show "Adult fish surround the young fish "results, so, the factor that interfere the structure of fish group is not so called "group defense by ethnologist".本研究目的,在探討影響魚群「成魚圍繞著幼魚游」的行為。本研究是以數學模擬法,依觀察結果,設定魚在受到刺激後,因體型大小、游速的快慢、靈敏度的差異等,所產生的不同的反應。再在方格紙上模擬魚群在捕食者出現時,游開的動線。最後分析成魚幼魚的動線分布情形,是否仍是「成魚游在幼魚外圍」的魚群結構。研究結果發現,依魚類的生理條件所設定的條件下模擬,自然形成「成魚游在幼魚外圍」的魚群結構。所以,影響魚群結構的因素,的確不是行為學家所說的防禦行為。

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.