熱巧克力效應之迷思
“熱巧克力效應”是當你將巧克力粉加入裝有熱水之馬克杯後用湯匙輕敲杯壁,可以聽出攪拌前後敲擊所得聲音頻率明顯不同,攪拌後巧克力粉溶解頻率會較高。一般論文的解答是「當粉末溶解的時候,藏在粉末裡的空氣就會跑出來,在空氣與水混合的環境裡,音速比在水裡低。當水裡不斷有空氣與水混進去時,這個容器的共振頻率和它裡面的音速有關,所以也會降低。因此你會聽到較低之音調,直到空氣全跑光。」但根據我的實驗我覺得這樣的解釋並不對。我們提出新的模型來解釋“熱巧克力效應”。When we put an ounce of dry chocolate powder into a mug filled with hot water, then tapping the side with your spoon will generate a sound. The pitch of this sound will rise after stirring. This is called “the hot chocolate effect”. According to a published paper, the explanation is “The air trapped in the powder is released as the powder dissolves. Since the speed of sound is lower in air than that in water, the speed of sound in the air-water mixture is lower than that in pure water. During that period while the air escapes the container, the resonant frequencies of the water, which depend directly on the speed of sound, will also be lower. Hence, you hear a lower tone until the air escapes”. However, our experiments clearly demonstrated that the explanation is plainly wrong. A new theoretical model is also proposed for the observed phenomenon.
微波加速轉酯化生成生質柴油實驗與結果分析
因國際原油價格上漲,因此對研究及發展具潛力的生質柴油引起高度興趣。傳統以加熱方式在適當觸媒下將低碳數醇類與油脂轉酯化生成生質柴油。但以強鹼為觸媒使用過量會讓部分反應轉為皂化。而利用微波,使微波腔在極短的時間內產生電場,使具有電偶極的分子朝向電場方向迅速排列而產生轉動,快速地增加分子間的碰撞頻率而加速反應,但不破壞分子結構。也嘗試利用超音波來生產生質柴油。試驗方法為利用SD-22 柴油引擎測試所生產的生質柴油,並收集廢氣檢驗,評估其污染性。實驗後發現,微波能將一般加熱所需的60 分鐘大幅縮短至4 分鐘,甲醇溶液能生產較多的生質柴油。其中1.40%氫氧化鉀甲醇溶液且油與醇莫耳比1:9 效果較佳。氫氧化鉀甲醇溶液0.80%且油與醇莫耳比1:5 效果亦佳。製成的生質柴油能讓引擎發動,廢氣處理後經分光光度計檢驗氮氧化物,生質柴油確實能有效減少氮氧化物污染。
Due to the fact that the price of international crude oil raises , people look for alternative energy resources actively. Therefore, I have great interests in doing researching and developing the biodiesel through many ways. The traditional way is to transesterify the low carbon alcohols and fats with the suitable catalysts by means of generally heating. However, the overuse of strong bases as catalysts may turn the experiment result into saponification reaction. This study made good use of the microwave to generate electric fields in the microwave cavity in an extremely short time. Owing to the effect electric fields exerted, the molecules with electric dipole momentum rearranged to rotate rapidly .Consequently, the frequency of collision among the molecules increased without destroying the molecule structures. Also, I applied SD-22 diesel engine to test the produced biodiesel and examined the collected exhaust to evaluate its pollutant. According to the results of these experiments, the conclusion was as following: the microwave could shorten the Transesterification reaction time from 60 minutes to 4 minutes. The methanol solution could produce more biodiesel than the ethanol solution. Besides, the 1.40 wt % Potassium hydroxide solution with the molar ratio of oil and methanol 1:9 had the best efficiency in producing biodiesel. On the other hand , the 0.80 wt % Sodium hydroxide solution with the molar ratio of oil and methanol 1:5 also had the great efficiency. All the biodiesel we produced enabled the diesel engine to run smoothly. The exhaust inspected from the examination of Spectrophotometer resulted that the biodiesel did less NOx pollution to the environment indeed.
8x8 棋盤路徑解之一般化推廣
Abstract (一)、 In our study, we discuss a m×n chess and any beginning square p finding a directed path of chessman from p moving to an end square in which the chessman moves to adjacent squares including only three directions which are right move, up move and diagonal left down move. A m×n chess is ruled into m columns and n rows creating the number of (m×n) squares (二)、 A chess directed path moves from any beginning square to end square in a m×n chess and every other square is visited just once. In the view of the beginning squares, the chess paths are solvable paths in a mxn chess and the corresponding squares are solutions. (三)、 First, we find out that some beginning squares are located in a special area with no any solvable directed paths. We define the special area be no-solution area. (四)、 According the 3-color theorem, we determine more than two thirds of no-solution area. (五)、 Then, we derive properties of reversibility and symmetry in solvable paths. i.e. A solvable path exist another solvable path by reversibility and symmetry respectively. (六)、 Utilizing the generalization of no-solution area which is extended from the concept of no-solution area provides judgment for the next moves effectively. The judgment is defined as effective move principle. (七)、 Furthermore, using the other theorem called rules of shift Hamiltonian path gets augment solutions. (八)、 According to the effective move principle finding a number of solvable directed paths, use the reversibility and rules of shift Hamiltonian paths to get augment solutions. Finally, utilize symmetry to find out all solvable paths in the m×n chess. (一)、研究規則:在m×n 的格子中,任取一格A 當作「起點格」,在起點格上放一顆棋子,只能往「上」、往「右」、往「左下」的方向移動。(二)、定義:若棋子從「起點格」,按照上述規則能不重複的通過所有m×n 格子到達某一「終點格」,則對於「起點格」而言,此移動路徑稱為m×n 的「有解路徑」,其任4一「終點格」稱為「起點格」的「路徑解」。(三)、我們先研究出「基本無解區」。(四)、根據遊戲規則我們利用三種顏色將n × n 方格塗滿,並判斷出大部分的「無解起點格」。(五)、利用遊戲規則得到兩重要性質:(1)[可逆性性質] (2) [對稱性性質](六)、利用「廣義基本無解區」,當作我們[有效移動]的判斷,讓「有解路徑」快速的找出。(七)、利用本研究所稱的「平移哈式鏈」,得到[擴充解]。(八)、根據[有效移動]求出部分「路徑解」,再利用[可逆性性質]、 [擴充解] ,最後利用[對稱性性質]完成所有「路徑解」的尋找。
奈米溶膠製成蓮花效應及應用
Lotus effect(蓮花效應)是蓮葉表面化學組成(wax)與物理組成(微纖維結構)兩者所造成。本研究是以模擬Lotus effect,採用Sol-Gel 製成,將氟化矽聚合為奈米膠體。實驗結果發現,以異丙醇為溶劑,再依序加入氟化矽、硝酸以製成的Sol-Gel,將其塗覆於玻璃表面,可得到最高的接觸角(114.71°),且少量的氟化矽可製成大量的成品,已具有實用價值又兼顧成本的優點,最重要的是,本研究克服了目前Sol-Gel 製程與應用的四大難題(機械強度、與基材接著問題、透明度、溶膠凝固問題),可說是一大創舉。利用所研發出來的奈米溶膠,我們能成功地將Sol-Gel 附著於布料、玻璃、釉表面、粉體,也能成功地研發出具有自潔透氣的布料、救生衣、雪衣、棉被及自潔功能的玻璃、磁磚與市面上尚未研發出的防水粉體(接觸角>140°),因此我們研發出的Sol-Gel 應用甚廣,有無限的發展潛力。Chemical composition (wax) and physical characteristics (microstructure) of lotus leaves are both responsible of the so call Lotus Effect. In this study we intend to demonstrate louts effect by applying Sol-Gel method to polymerize fluorosilane into nano-scale colloid. Our experimental results shown that the sol-gel made based on isopropanol solvent with fluorosilane and nitric acid added in order, when coated on glass plate, can achieve highest (liquid-surface) contact angle of 114.7 degrees. In addition, only small quantity of fluorosilane is sufficient to produce large amount of product, making this method feasible and cost-effective. More importantly, this procedure overcome the four major difficulty of sol-gel processing and application, namely mechanical toughness, adhesion with substrate, transparency, and consolidation. Using the nano-sol-gel developed in this study, we have successfully coated the sol-gel onto fabric, glass, ceramic grazing surface, and powder, which allow one to make self-cleaning breathable clothes, life jacket, snow cloth, futon and self-cleaning glass and tiles, as well as water-proof powder (contact angle > 140 degrees) which is brand new on market. We therefore believe that there is a great potential for the application of sol-gel developed in this study.
酒精對斑馬魚胚胎眼睛發育的影響
長期以來,臨床研究發現會影響人類胚胎的正常發育,造成胚胎畸形、成長遲緩等現象,稱為胎兒酒精症候群(fetal alcohol syndrome),但是其病理機制仍不清楚。最近的研究發現斑馬魚胚胎對於酒精有非常靈敏的反應,出現明顯的發育異常現象,例如心臟膨大、眼睛縮小、骨頭變形等現象,與人類胎兒酒精症候群相似,顯示斑馬魚非常適合作為研究胎兒酒精症候群的模式動物。在本實驗中,我們針對酒精影響視網膜神經發育的現象進行探討,並且也利用基因晶片篩選出胚胎發育時期受酒精影的的基因轉錄子,藉以了解酒雞造成胚胎畸形發育的機制。實驗結果顯示在眼睛發育過程中,1.5% 酒精浸泡會抑制視網膜神經細胞的分層(Lamination),而進一步利用RNA定位雜交的方式以眼睛的標示基因rx1、pax6b、six3b、alpha-crystallin、rho、neuroD、huC觀察他們的表現,發現酒精會減少視網膜神經細胞的分化,造成眼睛發育的缺陷。在基因晶片的分析中,我們發現酒精處理會抑制許多控制眼睛發育的基因調控子的表現,包括了crx、rybp、irx4a、optx2、rx1、brn3b1 與 vsx1等,此外約有16%的眼睛相關基因液受到酒精的抑制,遠高於其他基因受抑制的比例,顯示眼睛是酒精傷害最嚴重的區域之一。我們從實驗結果得知酒精並未對胚胎發育初期眼睛的發育造成明顯的影響,但是隨後由於控制細胞分化的幾個重要基因受到酒精抑制作用,造成視網膜神經細胞的分化停止,引起眼睛的異常發育的情況。It was known that prenatal alcohol exposure may cause serious birth defects and developmental disabilities. The molecular mechanism of this fetal alcohol syndrome still remains unclear. Here we used zebrafish embryo as a model to investigate the toxic effect of alcohol in retinal development. The histochemical analysis revealed that the cell lamination was prohibited by alcohol incubation. It appears that the retinal cell differentiation was inhibited. As revealed by whole mount RNA in situ hybridization, it appears that the transcription of a number of retinal-related regulatory genes, including rx1, pax6b, six3b, alpha-crystallin, rho, neuroD and huC, were all inhibited in zebrafish embryo by alcohol exposure. The transcriptional profile of alcohol-exposed embryos was also compared with normal embryos by microarray analysis at different stages. It appears that 16% of retinal-related genes were all repressed by 1.5% alcohol incubation, including several retina-related transcriptional factors, including crx, rybp, irx4a, optx2, rx1, brn3b1and vsx1. Our results suggest that alcohol did not interfere the early development of the eye, but has inhibited the final cell differentiation of retina cells. This study helps us understand the molecular mechanism of alcohol-mediated retinal malformation.
調幅超聲波解調高指向可聽音之研究
可聽聲有向四周擴散繞射特性,而超聲波具有指向性,改以超聲波載送可聽音訊號後,其載波與旁頻帶均在超聲波範圍,實驗中人耳卻可聽到高度指向性聲音,且調幅解調後的可聽聲衰減率比純超聲波來的低。那為什麼超聲波會解調可聽音?我們以非線性的數學轉換概念,成功以數學推導解釋實驗中所聽到的可聽聲,是由旁頻經由非線性轉換而來的。為了證實空氣中的超聲波有非線性現象,以發射40KHz單頻訊號,除了接收到40KHz訊號外還可接收80KHz訊號,而80KHz訊號振幅,會隨著發射強度而遞增,也會隨著傳輸距離增加至穩定狀態,這所我們從文獻中的非線性理論所吻合。接下來進行調幅超聲波實驗,我們經理論計算旁頻帶強度為頻率響應與調變率乘積的一半,而解調可聽聲的強度為調變率、頻率響應與非線性係數三者乘積,我們也由實驗數據證實理論計算結果,在實驗中,換能器在40KHz有最佳的頻率響應,其非線性係數與所載送可聽聲頻率高低約略成正相關,並且與換能器距離遞增而越遠而增加。此外在提高高指向可聽音輸出功率方面,除製作專屬的放大器、運用方波取代正弦波來載波、配合陣列換能器輸出;在改善音質方面,利用等化器調整訊源頻譜分佈,降低低頻振幅,增強高頻振幅,讓各頻率的原始訊號都能有適當的調變,達到最佳音質。The audible sound has the characteristics of spreading and diffracting. And ultrasonic is directive. We modulate sound into ultrasonic signal. The carrier and sideband are ultrasonic frequency bands. But in the experiment, human can hear highly directive sound. In terms of attenuation rate, AM demodulation sound is lower than pure ultrasonic wave. Why can human hear the directive sound? By using the nonlinear mathematical transform, we managed to explain the audible sound which is transformed from sideband with nonlinear effect in the experiment. In order to confirm that nonlinear phenomena in the air ultrasonic, we launch 40KHz single tone ultrasonic signal. Besides the 40KHz signal, we also received 80KHz signal. The amplitude of 80KHz signal will increase with the emission intensity, and also with the transmission distance to increase its stability. These are consistent with nonlinear theory in the literature. Next we began AM ultrasonic experiment. We calculated the sideband intensity that is the product of frequency response and modulation index. The demodulation sound intensity is the product of modulation index, frequency response, and nonlinear coefficient. We also proved the calculated consequence through the experiment. In the experiment, the ultrasonic transducer has a best frequency response in 40KHz. The nonlinear coefficient has positive correlation with the modulation frequency, and increases transmission distance. To boost the power of directive audible sound, we made an amplifier, using square wave to replace sine wave of carrier, and in conjunction with array transducer output. To improve the sound quality, We use the spectrum-Equalizer to adjust the frequency distribution of the origin signal. The EQ reduces the low-frequency amplitude, and boost high-frequency amplitude, which enables every frequency of the original signal to be properly modulated, achieving the best sound quality.