終端速度
液體中之球體運動與液體的黏滯性有關,本實驗找出球體半徑與終端速度之間的關係。利用攝錄機作為紀錄工具,拍攝三種材質(壓克力、玻璃、水晶)的球體在沙拉油中的自由落體過程。使用電腦影像處理軟體將影像分解成幅影像,時間的解析度為1/30秒。測量球體的高度與時間,分析高度與時間的變化情形,發現終端速度與球體半徑之間的關係。
流體中之運動方程Fdrag = -k1V,無法符合實驗結果。我們的實驗結果顯示油中的自由落體的運動方程應該是Fdrag = -(k1V+ k2V2)。由不同材質的壓克力球(~1.18g/cm3)、玻璃珠(~2.47g/cm3)與水晶球(~2.66g/cm3)所獲得的終端速度(Vt)與球體半徑(a)的關係為a3(ρ-ρ') = 0.00003(a Vt)2 + 0.00021(a Vt) + 0.00575,其中ρ與ρ'分別為球體密度與沙拉油密度(0.90 g/cm3)。
再者,在相同半徑的條件下,密度越大的球體終端速度越大,在靜止下落後,越久達到終端速度。
The motion of a sphere which is falling through a fluid is subject to the fluid viscosity. In this study, we find out the relation between the radius of a sphere and the terminal velocity. We used a digital camera to record the sphere's descent in the oil. The three kinds of sphere we choose are acrylic(~1.18g/cm3), glass (~2.47g/cm3)and crystal (~2.66g/cm3). Frame-by-frame analysis of the video footage yielded rough estimates of the sphere's location within 1/30 seconds accuracy for statistically consistent results. By measuring the location and time and analyzing them, we find out the relation between the radius of a sphere and the terminal velocity. The expression of the drag force,Fdrag = -k1V, is not cosistent with our results. The study indicates the expression of the drag force should be Fdrag = -(k1V+ k2V2). The expression for the terminal velocities of the three kinds of sphere is of the form:a3(ρ-ρ') = 0.00003(a Vt)2 + 0.00021(a Vt)+ 0.00575, where a is the radius, ρ is the sphere density and ρ' is the oil density(0.90 g/cm3). In addition, if the radius is the same, the terminal velocity of a denser sphere is higher and the time to approches the terminal velocity is longer.
揭開變化球的神秘面紗 --- 探討丘腦至前額葉的路徑連結
During the evolution of humankind, development of frontal cortex has played a critical role, where higher brain function like emotions, self-consciousness, decisions…etc, were all related to frontal cortex. On the other hand, thalamus is usually associated with relaying the sensory signals from peripheral receptors. In order to understand the functional role of frontal cortex, the signal processing mechanisms in the thalamo-frontal cortical pathway became an important research issue. The aim of this experiment was to find a method to dissect a brain slice that contains a connecting route in vitro between thalamus and frontal cortex with functional activity. Through nerve fibers tracking technique using fluorescent-dye (DiI), it was understood that the 3D-space connection between thalamus and frontal surface was an upward curve with a turn of about 110 degrees and bending inwards from the two sides. If a conventional horizontal section was performed, the route would be cut-off and its integrity lost regardless of the direction. To solve this problem, a novel section method was developed to retain the route. Based on the route direction shown by the fluorescent-dye, a piece of brain block was cut and flattened of about 110 degrees. Other sections were performed as control for studying the effectiveness of the sectioning on the plane of the route. Finally, electrophysiological methods were used to verify the connection route was complete and functional. Thalamus-evoked extracellular field potentials in the frontal cortex were observed by changing stimulation strength, adjusting slice temperature and prepared oxygen supply and administration of drugs like CNQX and picrotoxin in the 110 degree flattened slice but not the others. It was found that the reaction was essentially a neuronal response, indicating the pathway between thalamus and frontal surface was retained substantially. With this novel brain slice technique, we can assess the functional connection between thalamus and frontal cortex and investigate the cellular mechanisms of the signal processing in this connection pathway. It is anticipated that present technique provides an important step to further elucidate the functional role of the frontal cortex. 在人類的演化史上,前額葉的發展扮演了極為重要的角色,凡舉情緒、自我意識、決策等,皆與前額葉有關。而丘腦通常與視覺、聽覺及本體感受如痛覺、觸覺、溫度覺的訊息傳遞有關。要了解前額葉的功能,丘腦到前額葉的徑路及訊息處理機制,便成為一個很重要的研究課題。本實驗的目的是尋找一個方法能在離體的腦切片上維持具有丘腦到前額葉連結的徑路並且有功能的活性。經由螢光染料(DiI)神經束追蹤技術,了解從丘腦至前額葉路徑的三度空間連結為一先向下再向上約110度的角度轉折,並同時先由內向外再轉向內的曲線,若用一般水平之切片方法,無論何種方向,其路徑必定會被切斷,不能保持其完整性。為了解決此問題,發展出一種可以保存其路徑的腦切片方法。依照螢光染料所顯示出的的路徑走向,在腦塊的皮質上切一刻痕,將腦塊以110度的角度展平,使其路徑處在一個平面上再切片。最後利用電生理的方法來證明所切出的連結路徑是完整且具有活性。改變在丘腦的刺激強度、調整腦切片(腦脊髓液)溫度、氧氣的供給以及施予藥物CNQX、picrotoxin,觀察其前額葉之電位變化,發現其反應確實為神經反應,表示從丘腦至前額葉的路徑已在這種特殊的腦切片中被完整保存。藉由這個方法,將有助於研究丘腦至前額葉功能性連結,神經網路結構,及其訊息處理機制,並期待以這樣一個全新的方法將來有助於瞭解前額葉的功能。
蓮花自潔效應之成因機制
奈米科技是二十世紀末、二十一世紀初新興的科學技術,由於它是在1~100 nm(n = 10-9)的尺度內改造原子及分子排列,創造新物質【1】,將顛覆傳統改造物性,被預言將帶來人類的第四波工業革命,對物理、電子、光電、化工、材料、生醫、機電各領域帶來巨大衝擊。『蓮』是世界上最早的被子植物之一,在一億四千萬年前就生長在地球上,蓮的分布甚廣,從印度、中國、日本、北美到西伯利亞到處都有蓮的蹤跡。蓮的生命力強,很能適應環境,美國加州大學曾試驗培植古代蓮子,經過1300 年的沉睡,古代蓮子仍然正常發芽【2】。台灣的蓮花是十七世紀的移民,自中國帶來種植的。『奈米科技』和『蓮』這兩個不同年代的產物名詞如何連結在一起,他們怎樣相互依存;這正是本文討論的重點,也是了解『奈米科學』很好的例子。本文藉出汙泥而不染,闡述蓮花的自潔(self-cleaning)效應。一般在奈米技術中,簡稱『蓮花效應』【3】,包含清潔機制、成因;使用觀察紀錄自潔狀況情形,幫助對蓮花自潔過程的掌握。期望能對具有蓮花效應的奈米結構提供良好的意見。本研究的結果發現,蓮花效應強的植物,幾乎具有高抗水性。而抗水性是來自奈米結構和表層蠟質,這兩個特質也是蓮葉、芋頭葉等高蓮花效應的植物所具備的,所以我們推論:奈米結構和表層蠟質越發達,抗水性越好,則植物葉面的蓮花效應越強。Nano technology is one of the most advanced technologies now. Since it will alter and rearrange the fundamental structures of atoms and particles within the space of 1~100 nm (n=10-9) the coming industrial revolution depends on it. Nano technology will pose dramatic impact upon a variety of specific fields including physics, electronics, photon electronics, chemical industries and so on. Lotus is one of the most primitive covered-seed plants. It has existed since 140 million years ago and has spread in wide areas. The University of California made lotus seeds that have been frozen for 1300 years sprouted. The Taiwanese lotus seeds were transported from China in the 1600s. The researchers are to probe into the relationship between the nature of lotus and nanotechnology to understand the potential significance of this newly developed technology. The researcher employed the direct observation and tape recording to collect the objective data of the individual growth steps of lotus to analyze the self-cleaning effect of the lotus. In the conclusive part, the application of the Lotus Effect and the creative technology will be discussed and analyzed with the hope to prescribe both a conclusive experimental principles and a further direction for the manufacturing systems related to the developing Lotus Effect. The researchers of the study found that those plants, which have high quality of Lotus Effect, are given the nature of resisting water, which is the consequence of two features namely, the nano-structures and the surface wax. And the leaves of lotus, potato all have these two features. Therefore, it is inferred that the more efficient mechanism of the nano-structure and surface wax and Lotus Effects the plants are, the more effects of the water-resistance function will the plants achieve.
緩步門的木乃伊-會蟄伏的熊蟲
The study is to investigate Taiwanese tardigrades,and the research of that is few. Tardigrades are commonly called water bears and have been identified more than 750 species. Limno-terrestrial tardigrades are small, 0.2-0.5 mm in length, and mostly found in moss cushions growing on rocks, soil, or the wall of houses. When the environment dehydrates in dry weather, Tardigrades desiccate into a reversible state of metabolic suspension called cryptobiosis. We have been finding a number of tardigrades in moss at many places in Taoyuan country. First, we put the moss on the dissected microscope to seek for tardigrades, and then placed it on the microscope for photographing and observing. The study is mainly focus on Taiwanese tardigrades. we have classified 11 Taiwanese species in four families(Echiniscidae,Calohypsibiidae,Milnesiidae and Macrobiotidae), making Chinese keys of classification. From the habitat envoriment, the species, the density and the diversity we survey as well as the most suitable pH envoriment we experiment, we approach the relationship between the distribution of tardigrades and their habitat. Besides, we also research lots of conditions which bring cryptobiosis and make culture medium in order to inspect its living. These results indicate that tardigrades desiccate into cryptobiosis in ten munites in acid rain(pH4.65). From outdoor surveys, we have noticed tardigrades can’t be found in the moss right next to road.The length of each family is: Calohypsibiidae>Milnesiidae Milnesium>Macrobiotidae>Echiniscidae. 此研究是探討台灣熊蟲,而有關台灣熊蟲的文獻資料極少。熊蟲屬於緩步門,體長約 0.2-0.5 mm,熊蟲在不利的環境會蟄伏,環境有利時又會膨脹而復甦,而其構造系統不因此而破壞。 我們在桃園縣多處的苔蘚發現熊蟲,我們先將採集的苔蘚放至解剖顯微鏡下尋找熊蟲,再由複式顯微鏡觀察構造並拍照紀錄。研究主要是探討台灣本地的熊蟲,我們已分類出十一種台灣熊蟲,製作中文檢索表。藉由觀測採集環境和所測的密度、歧異度和種類,及實驗出其最適宜的 pH值,探討環境對其分布的影響。也探討各種因素與蟄伏的關係,製作培養基以觀測其生活史。研究結果顯示:1.已經分類出台灣有緩步門四科(端爪科、Calohypsibiidae科、Milnesiidae科和 Macrobiotidae科)十一種熊蟲。2. 污染嚴重或環境髒亂的地方,不會有熊蟲的存在,且熊蟲有群居性。3. 端爪科(棕色)熊蟲在 pH4.65(台灣都會區雨的酸鹼值)以下的液體環境活動力明顯降低。4.熊蟲多分布在高溼度(87.5~90.4%)的地方,不分布在中低溼度 (76%以下) 的地區。5. 各科的體長為 Calohypsibiidae科>Milnesiidae科 Milnesium屬>Macrobiotidae科>端爪科。
奈米使你變美了!-奈米二氧化鈦在化妝品上的應用
奈米的科學與技術將是21 世紀所要探討的方向。在了解奈米粒子的表面效應、小尺寸效應、量子尺寸效應、宏觀量子隧道效應後,發現其應用甚廣,諸如再生物、醫學、環境、國防、工業產品等方面,都將佔有很重要的地位。我們主要是利用溶膠-凝膠法來製造二氧化鈦奈米粒子,並了解二氧化鈦奈米粒子可吸收紫外線及光催化反應,將廣泛應用電子、紡織、塑膠、橡膠,空氣淨化及廢水處理方面。本實驗將利用二氧化鈦的吸收紫外線特性,來研究其應用在化妝品上面。The science and technology of nanomater will be the direction we will explore in the 21st century. After understanding surface area effect of nanometer particle, Small size effect, Quantum effect, and Macroscopic quantum tunnel effect, we can diswver the application is very far-fluing. For example:biochemistry, medical science,eneironment,national defense and industrial products,will devine a very important position.We mainly use sol-gel method to produce U-TiO?,and understand the absorption of UV and photocatalysis,plastics,mbber,purging air,and dealing with effluents.This experiment will use characteristic of absorbing UV of U-TiO? for researching the application of cosmstics.
液態導體的磁效應
本文所探討的議題為電解質溶滿通以電流後所產生的效應與機制。本實驗所採用的方法為電解與電鍍,運用這兩種方法,來比較電解液在不同狀況下所產生的結果;經過多次的實驗,累積了許多實驗結果,使我們可以得到更精確的數據 · 在此次實驗中,我們發現電解液在相同的電壓下,通以電流後的穩定性與金屬的活性有關,活性越大越不穩定;反之,活性越小越穩定。另一個發現為,只有單一極性離子移動的情形,可通過的電流,比陰陽離 r 同時移動時為大;但因通過的電流大使電解液反應劇烈,產物時時覆蓋電極使電流下降。所以就穩定性來說,是以陰陽離子同時移動為佳 · 在展望方面,希望可以發展到液態磁屏避的設備,可減少設備過重之問題 ·This is a study of how electric current effects the electrolyte solution. The experiment was conducted through two methods: electrolysis and electroplating, the results of which were compared. The experiment of the same designs hi been conducted repeatedly and, as a result, accurate data were collected and accumulated.One of the two major findings from the experiments was that, when under the same voltage, stability of the electric current varied with the change of activity of the metals; the greater the activity of the metals, the less stability of the current, and vice versa. The other major finding was that, with the movement of dipole-ion, a greater amount of current would go through the solution than that which would go through with the movement of cathode and anode; however, the greater amount of current would cause intense reaction of electrolyte solution, hence merging the electrode and reducing the current. So as long as stability is concerned, the movement of cathode and anode is preferable.It is hoped that more sophisticated experiments designed on the basis of the similar principles will eventually lead to the construction of equipment of liquid-magnetic shielding of smaller weight and size.
以珊瑚蛋白及光頻轉換分子改善太陽能電池效率之研究
能源危機日益嚴重,開發再生能源成為當務之急。在諸多的再生能源之中,太陽能最易於使用,且可源源不絕的不斷取得利用。但目前太陽能電池的效率始終不高。其中重要的原因是太陽本身的頻譜多為短波長,並不適合絕大部分頻譜響應較佳,多為長波長的太陽能電池。目前改善效率方式,多為改變太陽能電池的頻譜響應以配合太陽之頻譜。本研究提出反向思考的概念,藉由頻譜轉換的方法,改變照射在太陽能電池上的太陽光頻譜,以提升太陽能電池的效率。本研究利用一種珊瑚礁的螢光蛋白質(DsRed)以及人工合成的螢光染料(Cy-5)最為本研究的頻譜轉換的材料,加於低成本,目前市場佔有率較大的單晶矽太陽能電池上,經由理論與實驗的結果顯示,增加的發電效率約為3~5%,證實利用頻譜轉換的概念確實可以提升太陽能電池的效率。Energy crisis has become more and more serious in recent years, which makes recycled-energy development is a must. Among different recycled energies, solar power has two advantages, that is, easy-to-use and endless supply. However, the conventional solar cell makes poor use of the solar spectrum because the solar spectrum is mainly composed of short-wavelength, which can’t fit to most of solar cells which is more sensitive to long-wavelength. Currently, the major method to improve the efficiency is change the function of spectral response, such as concentration lens, tracking devices, and antireflection coating. Up to now, no one notices the possibility of changing solar spectrum yet. This research provides an insight into this issue. Instead of changing the function of spectral response, I changed the solar spectrum, which irradiates solar cells through spectrum conversion to improve solar cells’ efficiency. This research uses one kind of coral fluorescence proteins (DsRed) and one kind of artificial fluorescence dyes (Cy-5) as the materials of spectrum conversion. Then coat them on the low-cost and high-market-share mono-crystal-Si. According to the theories I researched and my experiments, the improvement of the efficiency is about 3~5%, which proves it is actually useful to elevate the efficiency of solar cells through spectrum conversion.
溫泉中的秘密
The experiment was primarily focused on studying whether the enzymes from different bacterial species collected in various hot spring areas still exhibited activities at high temperatures. A further study would be conducted on analyzing the unique characteristics universally found in the genes of selected bacteria. First, hot spring samples were collected form Peitou and Wulai, and then cultured on the PY, PTG, MFB, and TS media in the laboratory. After the broth media growing with thermophilic bacteria, a series of continuous dilution method and solid-plate spreading were applied to separate these bacterial clones. The genomic DNA of the selected bacteria was extracted and used to analyze subtilisin-like gene by polymerase chain reaction (PCR) and electrophoresis. Finally, we examined the six selected thermophilic bacteria with the enzymatic activities of fibrin- and milk-protein degradation. We successfully concluded the experiment by proving that these thermophilic bacteria still exhibited significant enzymatic activitives in the high-temperature environments. The results of this experiment can be applied in numerous fields, for example, thrombus treatment and food processing, and a more in-depth study shall warrant the due consideration. 這次的實驗,主要是研究在不同的溫泉區中所採集不同種類細菌,是否酵素在高溫下仍具活性,如果有,再進而研究它們的基因有何特別的共同之處。首先,我分別自北投和烏來採集水樣,到實驗室後再以PY、PTG、MFB 和TS 四種培養基做細菌的培養,接著再利用連續稀釋和固態塗抹來做細菌的分離。經過挑選和培養之高溫菌直接進行DNA 的抽取,並利用「聚合?鏈反應」和「電泳跑膠」技術分析其類似蛋白質分解酵素subtilisin 基因。另外,本研究同時針對所選定之6 株高溫細菌利用血栓和牛奶蛋白來測試其蛋白質分解酵素的活性。由以上實驗結果可以證明某些細菌在高溫的環境下酵素仍具活性。這次在高溫菌的實驗結論,可應用在很多地方,例如:血栓的治療、在高溫下食品處理‧‧‧等,應用相當廣泛。