見微知「駐」-水珠律動與圓駐波
It is always fascinating to see water droplet’s dancing around on a Japanese teppanyaki hotplate surface. The water usually does not evaporate immediately, but form interesting shapes, dance around and follow by evaporation of gaseous water and disappear. In this experiment, we designed a very simple experimental set-up to observe the little water droplets dancing on a heated hotplate. A homemade stainless plate and a small heater attached to the plate, and a thermal couple was assembled. With this simple setup, we observed the variation of water droplet’s shape as a function of the hotplate temperatures. The temperature of the water droplets, the duration of the water on the hotplate, and the shape number were measured. The shape formation mechanism was proposed. We found when the water droplet was subject to high heat due to the contact of the surface and the hotplate, the abrupt evaporation of the water molecules and violent vibration cause the formation of the various shapes to reach thermal equilibrium; the number of the shapes and the oscillation can be described by Laplace’s equation,Using a high-speed camera, we found the higher the temperature of the water, the more variations of the water droplet shapes can be observed. In addition, at a certain temperature range, the number of the water shapes did not change, suggesting a similar phase transformation behavior on the shape formation.
緣起: 邂逅專題研究、水珠漫舞、剪輯影片,引起我們想更進一步揭開它的神秘面紗。
緣續: 了解熱平台上水滴大小的變化及水珠基本的形狀及變化律動。
緣繫: 進一步研究水珠多變的面貌,並探討水珠的大小、溫度、停滯時間及變化規律相關機制。
緣定: 糾纏在水珠圓舞曲中有如大珠小珠落玉盤的曼妙,其中埋藏了平均圓與能量量子化的律動。
稀子蕨的生殖策略探討
稀子蕨(Monachosorum henryi Christ)生長在台灣中海拔山區,是少數具有特殊生殖方式(不定芽)的蕨類。本研究對東眼山的稀子蕨族群進行物候調查,以了解其進行孢子繁殖及不定芽繁殖的過程,並試圖探討稀子蕨的不定芽是否可增加其族群對環境的適應性。研究結果顯示稀子蕨的孢子體及原葉體都無法在乾旱的環境下生存,常有大規模乾死的現象;而其不定芽則具有很強的耐旱性,無論是在季節普遍性及幼苖發育程度上,生殖芽都比孢子繁殖較佔優勢。而且其不定芽於旱季結束後,可迅速萌發,長出的孢子葉可隨之進行有性(孢子)及無性(不定芽)生殖,使其族群不至於在旱季中有地區性滅絕之虞。;Monachosorum henryi Christ , which exists in the middle elevations of the mountainous regions of Taiwan, is a fern with a special reproductive system seldom found in other ferns.This study investigates the phenology of Monachosorum henryi population in the Don Yang mountain region. Its purpose is to understand the sexual and asexual reproductive cycles of these ferns and to interpret whether or not the buds can increase the fitness of their population during the dry season.The results show that it is extremely difficult for the sporophyte and prothallus of Monachosorum henryi to survive in a drought. However, the buds have a much stronger drought endurance. According to this investigation, the adventitious buds of Monachosorum henryi are superior to the spores in seedling development in every season. Adventitious buds are able to germinate soon after the dry season as well as in any other season, and are able to grow spores and buds on their fronds enabling both a sexual and asexual way of proliferation. In this way the fern avoids a district extinction of their population.
溫差電池的熱力學研究與應用
溫差電池中若僅進行的反應,則其電池電壓與溫差成正比,且純粹是利用化學反應將熱能轉換成電能,我們稱之為「典型溫差電池」,由熱力學公式可推導出典型溫差電池的電動勢(ΔS = S(s)—S(aq),S為絕對熵, n為得失電子數,1F = 96487 C ),且得到下列三項推論來說明溫差電池的特殊現象。 (1) 同一溫差電池,其電動勢與溫差成正比 (ε∝ ΔT)。(2) 不同的溫差電池,當溫差一定時,電壓ε 與ΔS 成正比,與得失電子數n 成反比。典型溫差電池中,電解液濃度越小,金屬離子濃度也愈小,會使得ΔS = (S(s)—S(aq))的絕對值變大,因此溫差電池的電壓也就愈大。(3) ΔS 值的正負決定電壓ε 的正負。Cu(NO3)2 及ZnSO4 溫差電池的ΔS 為正值,所以高溫杯為正極;AgNO3 溫差電池的ΔS 為負值,所以高溫杯為負極。因水溶液中陰、陽離子不能單獨存在,所以單一離子水溶液的絕對熵無法求得,但科學家把氫離子水溶液的標準絕對熵定為零,藉以求出其它離子的絕對熵,然而我們測得在一定溫差時典型溫差電池的電動勢ε,再查得金屬的標準絕對熵 S(s),代入S(aq) = S(s) — nFε/ΔT,便可得到離子水溶液的絕對熵。Cu(NO3)2 溫差電池的電解液中若含有1M 或0.5M 的KNO3,電池電壓仍然與溫差成正比, 但卻可獲得較大的電流,我們稱此類溫差電池為「改良型溫差電池」。我們利用改良型溫差電池的原理,自製環保、節約能源、可重複使用的實用溫差電池,以PVC 水管當容器,上、下兩端開口用銅片封住當電極,管內裝海棉及0.125M Cu(NO3)與 1M KNO3 溶液,熱源加熱上層銅片形成溫差,當溫差維持在70℃,電壓約為70 mV,若串聯30 個實用溫差電池,電壓可達2 V 以上,就可以對鉛蓄電池充電。實用溫差電池的熱源可由回收冷氣機、工廠的廢熱,或直接利用太陽能來當熱源。
If the temperature difference cell only goes through the following reaction Then the potential created by the cell is proportional to the temperature difference, and such a reaction purely changes the thermal energy into electrical energy through chemical reaction, which we often name it “typical temperature difference cells”. We can come to the following formula for the typical temperature difference cells through a series of thermodynamic formula: ε= ΔT . ΔS/ nF (ΔS = S(s)—S(aq), where S is the standard 3 entropy, and n is the number of electrons gained or lost, and 1F = 96487 C). We also provide the following three inferences to demonstrate the special phenomenon for the temperature difference cells: 1. Within the same temperature cell, the electromotive force (EMF) is proportional to the temperature difference. 2. When the temperature difference keeps constant, the electromotive force is proportional to the ΔS in different temperature cells, and is inversely proportional to the number of electrons gained or lost. Within the typical temperature difference cells, when the concentration of the electrolyte becomes more diluted, the concentration of the metal ions also proportionally become lower, which will make the absolute value of the following equation bigger, as a result, will make the electric potential of the temperature difference cells bigger: ΔS = (S(s)—S(aq)) 3. The value of ΔS decides the value of the electromotive force. The ΔS of the following temperature difference cells is positive value: Cu(NO3)2 and ZnSO4 . As a result, within the copper and zinc temperature difference cells, the higher temperature glass is the anode. On the other hand, the ΔS of the AgNO3 temperature difference cell is negative, which means that within the silver temperature difference cell, the higher temperature glass is the cathode. Meanwhile, because the cations and anions can not exist alone, therefore, it is not possible to find the standard entropy of the single ion solution. However, scientists define the standard entropy of the solution containing hydrogen ion to be zero, as a result, we only have to determine the electromotive force for a typical temperature difference cell, while keeping the temperature difference constant, followed by finding the standard entropy for the said metal S(s). Inserting it into the following equation to find the standard entropy for the ion solution. S(aq) = S(s) — nFε/ΔT If the electrolytes for the Cu(NO3)2 temperature difference cell contains 1M or 0.5M KNO3 , the electromotive force is still proportional to the temperature difference, and we can obtain bigger electric current. We call this kind of temperature difference cells “improved version of the typical temperature difference cells”. We try to make more environmental, energy saving, and recyclable temperature difference cell by applying the theory of the improved version of the typical temperature difference cells. We use PVC water pipe as the containers, both edges of the pipe sealed with copper metals, also work as the electrodes. Within the pipe filled with sponge and 0.125M Cu(NO3) and 1M KNO3 solution. The heat source keeps heating the upper copper metal to keep constant temperature difference. When the temperature difference is kept around 70℃, the electric potential is 70 mV. If we can connect 30 practical temperature difference cells in a series, the electric potential will reach 2V, which can then charge the lead rechargeable battery. The heat sources of the practical temperature difference cells can be supplied by the recycled air conditioners, heat waste from a factory, or directly comes from the solar power.
以離子溶液催化醇與酸酐的之酯化反應
在酯化反應中,經由實驗結果,我們發現離子液體對於此反應有催化的效果。離子液體 是在室溫下呈現液態的離子化合物,將醇類與酸酐放入離子液體中有助於酯化反應的進行, 基於這個新的發現,我們開始尋找使用不同種類的離子液體做實驗,選出適當的離子液體, 並且測試離子液體在不同環境下的催化效果,以及適合的使用計量;更進一步,我們找出離 子液體在催化反應之後,將離子液體回收的方法:利用有機溶劑將離子液體和產物分層並萃 取出產物,把離子液體回收再利用,符合現代推動綠色化學的趨勢。接下來我們探討離子液 體對催化反應的擴展性與應用,先由不同結構的一級醇反應到醯胺鍵的生成,最後推展到合 成阿斯匹靈,實驗結果說明,用離子液體做催化劑,也可以成功的合成阿斯匹靈。 We have established for the first time that ionic liquids, which possess the property of Lewis acid, can facilitate acylation of alcohols with anhydrides to form esters with photo-excitation. With the initial finding, we then screen through different types of ionic liquids with varying counter anions, loading, and external light or heat sources to sort out the best reaction conditions. To gain insights into the working mechanism, the dynamic profile of the catalytic reaction was monitored by analyzing the reaction mixture by using ‘H NMR spectroscopy. The ionic liquids can be recovered by extractive separation from the acylation product, which meets the major theme of green chemistry. To extend the substrate scope and applications of the new catalytic process, different functional primary alcohols and amines were further examined. More importantly, we have utilized the new catalytic protocol for the acetylating of salicylic acid, leading to aspirin with high efficiency.
由6面Sicherman骰子來分析n面的Sicherman骰子
Sicherman 已經找出與兩顆六面的正常骰子有相同機率分布的Sicherman 骰子,並進一步獲得與三顆六面的正常骰子有相同機率分布的骰子必為一對Sicherman 骰子與一顆六面的正常骰子之結果,我們試圖由已知的Sicherman 六面骰子的處理方法出發,透過對割圓多項式的分析來累積足夠的相關資料,以處理由兩顆四面骰子至兩顆三十面骰子,處理由三顆四面骰子至三顆三十面骰子的各種Sicherman 骰子的答案,來探索兩顆與三顆的n 面Sicherman骰子存在的充要條件與求法,並進一步將所得之結果分類,得到 ”有相同標準分解式的類型的數n,會具有相同組數的Sicherman 骰子”之猜測結果與特殊情形下的證明。 Sicherman has found out the Sicherman dice which have the same probability distribution as the normal two six-sides dice. Furthermore , he also found out a pair of Sicherman dice and a normal six-sides dice has the same result as 3 normal six-sides dice . We try to begin with the given algorithm of six-sides Sicherman dice , through the analysis of Cyclotomic Polynomials to accumulate sufficient related information then to come up with the solution from discussion of 2 four-sides dice to 2 thirty-sides dice , from 3 four-sides dice to 3 thirty-sides dice to explore the existence of necessary and sufficient condition and solution of 2 n-sides Sicherman dice and 3- sides Sicherman dice , and even to classify the results to come to a conclusion of the guessing results and proofs under special cases about “the numbers n which have the same Canonical Prime Factorization will have the same numbers of n-sides Sicherman dice.”