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.
無尾翼飛行器之穩定與控制
無尾翼飛行器(Tailless Aircraft)在軍事上的價值極大，且對於目前正在起步的微飛行載具(Micro Air Vehicle)而言，亦是值得嘗試與投資的。然而，由於無尾翼飛行器缺乏用以平衡的水平尾翼，造成其靜態的不穩定，即使設法提高靜態穩定特性，但其氣動力阻尼低、穩定性仍舊不佳。操縱上更是困難，在飛行穩定性與控制系統設計上極其挑戰性。本研究目的在探討無尾翼飛行器之穩定性與控制技術，改善其先天之不穩定特性，考慮之項目有縱向靜態穩定性、動態穩定性、控制面與組件配置等因素等進行詳細之探討。首先，找出了適用於無尾翼飛行器之Reflex翼形，接著建立無尾翼飛行器之非線性縱向動態模式，然後針對一翼展8Ocm之小型飛行器進行外型設計，並觀察分析其實際飛行狀態，再以理論與經驗公式估算無尾翼飛行器之氣動力導數，探討其飛行穩定與操控性能。此外，並運用古典控制PID控制法則，設計控制器進行非線性受控系統之動態響應模擬。由模擬結果可看出，經由翼剖面改變與控制系統的輔助下，大幅提高了其性能，使得無尾翼飛行器克服了先天的不穩定特性，更提高了其發展空間 The tailless aircraft has a great value on the military use. Meanwhile, it is worthwhile to try and to invest in it for the investigation of MAV(Micro Air Vehicle), which is being developed now. However, because of lacking horizontal tail which is used for balance, the tailless aircraft is static unstable. Even with the attempt to enhance its characteristics of static stability, the stability of the tailless aircraft is still poor for the sake of it's low damping in aerodynamics. Therefore, it is a challenge to flight stability and control system designing. The purposes of this research are to study the stability and the control technique of the tailless aircraft. To improve its congenital lacking of stability, thought over the longitudinal static stability, dynamic stability and control system. First, find the "Reflex" airfoil is suitable for the tailless aircraft. Second, set up a non-linear and longitudinal dynamic model of the tailless aircraft. Third, design an 80cm span small airplane. Hence, observe and analyze its flying condition. Finally, utilize the theoretical and experiential equations to estimate the aerodynamic derivatives and investigate its stability and controllability. Besides, use the PID controller to proceeded the time-response simulation of the non-linear system. The result of simulation shows that the performance is improved through the change of the airfoil and with the auxiliary of the control system. With this improvement, the tailless aircraft overcome the congenital lacking of stability to broaden its utilization potential.
明察秋毫-金屬的熱膨脹
Thermal expansion exists in our daily life. However, thermal expansion is generally too slight to be seen by naked eyes. Therefore, in the present project, a dilatometer was assembled to enhance better sensitivity toward thermal expansion. Hopefully the self-assembled dilatometer could contribute to teaching purpose.The structure of our 4th generation dilatometer is showed below. Using an ‘L’ square to hang up the metal stick and a rolling needle with a mirror to reflect the laser light are the critical parts of this equipment. By using this special reflection mechanism, the slight expansion of a metal stick caused by heat can be enlarged to a large scale. This special mechanism is where our creativity laid. Measuring in millimeter (mm), the measurement precision of the equipment can be extended to 0.0001 decimal. Our dilatometer was used to measure the expansion of various metal sticks caused by the temperature changes. Results were drawn from analysis of the data: 1) The average relative deflection was within 1.0~1.8%; 2) The relative deviation of linear thermal expansion coefficient was within –1.2~-4.4%.
物質熱漲冷縮的特性普遍存在於我們的生活環境中，但因其變化量相對微小，一般並不容易直接觀察，爲了進一步研究這課題，我們組裝偵測熱膨脹的儀器，並希望儀器的靈敏度高，能推廣為教學器材，經過我們不斷努力與改良，終於有了令人愉悅的成果。
自製第四代熱膨脹儀的結構如圖，設計「角尺懸吊金屬棒」與「滾針及鏡面反射」是儀器的重要部份，利用滾針旋轉及鏡面反射雷射光，加乘放大熱膨脹的微量變化，這是我們主要的創意，以公厘（mm）為單位，儀器的精確值到小數第四位。
利用自製的熱膨脹儀，探討金屬熱膨脹的影響因素。分析實驗所得數據，平均相對偏差在1.0~1.8﹪，而線膨脹係數的相對誤差約-1.2~-4.4﹪。
直接乙醇燃料電池之觸媒層研究
直接乙醇燃料電池以酒精與氧氣透過氧化還原反應產生電能，但化學反應緩慢，需利用觸媒以增加其速率。本實驗目的在於盡可能找出一個表現最佳的觸媒。本實驗利用活性碳粉作為觸媒（鉑、錫）的載體，以酸性（HNO3）與鹼性（NaOH）環境分別處理碳粉，再以含浸法與多元醇含浸法將觸媒還原。我們得到以HNO3 處理的碳粉無法保有原碳粉的型態，較利用NaOH 處理為差。在觸媒製備方面，多元醇含浸法還原效果比含浸法可得到較小的觸媒尺寸，在本實驗中，溶液中鉑與加入的碳粉重量比為3:7 時，可得到最大的反應面積。此外，當鉑與錫原子數比為4:1 時，可得到最大的乙醇氧化電流。Direct ethanol fuel cell is a kind of power source which generates electrical power by a redox reaction involving ethanol fuel and oxygen. However, this reaction takes place slowly; therefore, catalyst is needed to improve its activity. The goal of this project is to get an optimize catalysts ratio to obtain the best catalyst activity. Activated carbon is used as the support of catalyst (platinum and tin) particles in this project, which is pre-treated in acid (HNO3) and alkaline (NaOH) solutions respectively. Then, the precursor is reduced by impregnation and EG-impregnation. We learned that activated carbon pre-treated with NaOH activates better than which pre-treated with HNO3 because the latter bear less resemblance than the former. As for the catalyst, the results of EG-impregnation show smaller size of catalyst particles than those of impregnation. In this project, when the ratio of the weight of platinum and activated carbon added into the solution is 3:7, we can get the largest surface area. In addition, when the ratio of the amount of platinum and tin atoms is 4:1, we can get the largest current of ethanol oxidation.
繪身繪影-正三角形磁磚設計方法與碎形密舖之研究
本研究主要以正三角形作為基本單元，透過窮舉討論得到正三角形邊的作用方式只有五種，再經由排列組合歸納出11 種正三角形密鋪磁磚設計方法。進一步，運用我們的研究結果，配合數學簡報系統製圖，創作新圖樣，也彌補了Escher 在手繪時所造成的誤差，達到完全密鋪的效果。碎形磁磚的部份，我們也依據其背後的數學理論創作幾套結構圖，利用結構解析，碎形密鋪磁磚將變得十分容易，學習者將可輕鬆製作富有創意的新圖樣。 ;This research mainly takes the regular triangle as the basic unit. Through the enumeration, we obtain that there are only five operations for edge of the regular triangle, and then 11 kinds of regular triangle design methods are induced. Even more, utilizing our findings and Mathematical Presentation System (Math PS), we created the new pattern which makes up Escher’s errors and achieves the tiling. As to Fractal Tiling, we create several sets of structure drawings according to its mathematics theory. Using structure analysis, the Fractal Tiling will become extremely simple, and the learner can make the rich creative new pattern easily.
溫度與光週期對淡黃蝶的影響
為了了解淡黃蝶Catopsilia pomona無紋型crocale-like及銀紋型pomona-like中間受到環境因子的差異。先比對兩型的粒線體ＤＮＡ，之後模擬夏季和冬季自然環境進行實驗。得知兩型為同種。另一方面進行溫度和光週期的實驗，顯示淡黃蝶幼蟲和成蟲雌雄個體各部位會受到此兩環境因子的影響。In order to realize if Catopsilia Pomona and Catosilia crocale are the same species, we analyzed and compared the DNA sequences of Mitochondria, and the result revealed they are indeed the same species. Then we observed the developmental process of the butterfly, and inspected the effects of different factors: photoperiod and temperature were shown to affect the phenotype of the butterfly; lower temperature and shorter day resulted in phenotypic shift from crocale-like to pomona-like, and vice versa. Also, the conflicting factors produced intermediated form. (e.g. lower temperature with longer day) Not only changed the phenotypes of adult with photoperiod and temperature, those of larvae also did. However, the mechanism how photoperiod and temperature affect the phenotype of the butterfly is unknown.