探討聲致發光效應中,改變溫度,濃度,液體種類,頻率對氣泡發光的影響?
聲致發光效應(sonoluminesence)為最近二十年來相當新穎的研究領域,其基本原理是利用超聲波將水中的氣泡集中,並使之隨著超聲波快速且連續的膨脹壓縮,當氣泡被壓縮至最小時溫度急遽上升,並放出藍白色的光芒。正因為這是一個嶄新的領域,所以許多實驗是以嘗試錯誤的方法去進行,但也因此發現了一些特殊的現象:1. 氣泡在正常的頻率(30kHz)以外,經過一段不可發光的頻率後,還可在更高頻率(接近40kHz)的地方發光2. 氣泡發光效率曲線在不同性質溶液中的差異3. 針對高頻率發光及雙泡發光的部分,做了兩個相關的假設並進一步驗證,得到了相當特別的結論。至今已有許多關於此研究的成果發表,但對於同時兩顆氣泡存在並發光的雙泡發光現象(double-bubble sonoluminesence)卻還很少人研究。因此我們嘗試較系統化地分析雙泡發光,期望能夠對這個現象有進一步的認識,並對日後的多泡發光(muti-bubble sonoluninesence)研究奠定基礎。Sonoluminescence has been a very popular topic for the past twenty years. Single-bubble sonoluminescence occurs when an acoustically trapped and periodically driven gas bubble collapses so strongly that the energy focusing on collapse leads to light emission. Because it is a new topic, few related experiments on this issue have been carried out before. However, while doing the research and making adjustments at the same time we discovered some special phenomenon: 1. Besides the normal amplitude frequency (30kHz) added on the bubble, we found that after a period of frequency which can not emit, the bubble is able to remain and emit in higher amplitude frequency (about 40 kHz). 2. We also compared the emission efficiency when bubbles are in different liquids. 3. To explain part of the results in high frequency and double-bubble sonoluminescence, we made two assumptions and attempted to demonstrated them in the end of the report. Some research studies in this field have been released already; nevertheless, few people concentrate on “double-bubble sonoluminescence.” Therefore, we attempt to systematically analyze the emission of double-bubble, expecting to have more comprehension of this marvelous effect and also establish the fundamental background to “muti-bubble sonoluninescence.”
鋅電極低污染性金屬浸鍍處理對銀鋅電池的影響
Because the electrolyte solution used in an alkaline battery is a concentrated KOH solution, the zinc electrode in such a battery undergoes both a charging reaction and a corrosive reaction with the alkaline solution. The corrosive reaction not only reduces the lifetime of the battery but also produces hydrogen, which can cause the battery to explode and burn. Most of the zinc alkaline batteries currently on the market use mercury plating on the zinc electrode to increase its resistance to corrosion. To reduce corrosion of the zinc electrode in an alkaline battery and to avoid the use of toxic mercury, this study aimed to design a device to measure the quantity of hydrogen gas produced during the charging of a zinc-silver battery. We plated the zinc electrode with the immersion electroless plating method, using several different kinds of low-polluting anticorrosive additives(metallic compounds such as lead, tin, and indium)instead of mercury. We also used the vacuum immersion electroless plating method and added zincate ion into electrolyte solution to reduce further the quantity of hydrogen produced. The results of the experiment revealed that either a 10:1 or 100:1 ratio of lead to tin under optimal conditions will yield much better results than mercury.鹼性電池中使用的電解質溶液為濃氫氧化鉀溶液,因此電池中的鋅極除了放電反應之外,也會與濃鹼溶液中發生腐蝕反應。鋅極的腐蝕作用不僅會降低電池放電壽命,而且所產生的氫氣更可能使電池發生爆裂燃燒的危險。目前市面上所售之含鋅鹼性電池,大多是用鋅極鍍「汞」作為鋅極抗腐蝕的方法。為了改善銀鋅鹼性電池中鋅極在放電時的腐蝕效應,以及減少其所產生的氫氣量,本實驗設計了一動態放電裝置,可用於檢測銀鋅電池的放電電壓、放電時間與鋅極腐蝕反應的氫氣生成量。本研究藉由浸鍍其他低污染性金屬溶液 (鉛、錫、銦的化合物)來取代不環保的鍍汞製程,並進一步設計抽真空的浸鍍裝置,以及電解質溶液採用含有ZnO22-的KOH溶液,有效的降低電池中氫氣生成量。最後綜合所有優良條件,以鋅極採用真空浸鍍(Pb:Sn)為(10:1)及(100:1)的條件,此舉非常有效地提高電池中鋅極抗腐蝕性。此項製程所使用的Pb、Sn污染性質遠遠低於目前工業上所使用的汞製程污染,而且製程成本也遠遠低於Hg製程成本。
The role of miRNAs in plant development and virus defense
微型RNA是最近發現的小RNA,調控生物體內的反應,包括生長、細胞分化、對抗病毒…等。植物利用RNA干擾 (RNAi) 或過敏反應 (HR) 對抗病毒感染。有趣的是,miR168可藉由降解mRNA或抑制轉譯,調控阿拉伯芥AGO1的表達,而AGO1是RNAi的一個重要元件。miR398則調控銅鋅超氧化物歧化? (CSD1, CSD2) 的表達,而CSD1, CSD2負責產生過氧化氫去引發細胞凋亡 (cell apoptosis)。帶有竹嵌紋病毒 (BaMV) 全長基因的轉殖菸草 (Nicotiana benthamiana) 品系27-17是我們的研究材料。27-17的幼葉不具病徵,隨著葉子的生長,病徵會漸漸變嚴重。我發現被病毒感染時,植物會提高AGO1的表達,使RNAi更有效率。然而,病毒藉提高miR168使AGO1的量無法上升。植物亦可提高CSD1, 2 mRNA的量,促進細胞凋亡。病毒卻會引發miR398降解CSD2 mRNA。在病毒力價高的葉子中,雖然CSD2 mRNA降低且miR398升高,植物仍可大量提高CSD2蛋白的量。CSD1 mRNA沒有被miR398負調控,詳細原因仍有待研究。
平面切立方體內單位立方格數極值之計算
我們先假設有一正方體及一截過正方體之平面,並設正立方體為一k*k*k 之立體。為計算平面截過之單位正立方體個數,我們必須先分別計算各層被切過之個數再將之相加,因此將各層面投影至同一平面,簡化為平面上之問題,並討論其性質/規律,計算平面截此正立方體之個數。如此,便可以一般化數學式計算平面截正立方體個數之問題。接著,用以上方法為基礎,討論各種平面切正立方體之類型,將被平面所截之單位立方體個數以電腦程式算出,觀察數字變化及其性質規則,並找出最大值發生之條件。 We initially supposed that there are a regular hexahedron consists of unitary n × n cubes and a plane which incises the regular hexahedron. To calculate the total number of the unitary cubes incised by the plane, we can first calculate them layer by layer and then sum them up. And further, we project each layer on the same plane, so the three-dimensional problem is simplified into two-dimension. By making use of the character which results from projection, we can easily calculate the number of the unitary cubes incised. Consequently, we are able to calculate them with a general equation. Afterward, we research each circumstance that the plane incises the regular hexahedron on the base of the mentioned methods. Calculate them with self-designed computer programs, and observe the regulation and change of the result. Furthermore, we can find out when it will achieve the maximum.
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.
澱粉?抑制劑之研究
植物合成澱粉?抑制劑可以對抗動物的取食,國外實驗證明數種澱粉?抑制劑對害蟲防 治具有顯著效果,其中以腰豆(Phaseolus vulgaris)研究最多。我們利用5% T.C.A.進行粗萃,從台灣常見豆類中篩選出四季豆(與腰豆同種不同品系)與菜豆,對麗蠅的澱粉?具有明顯的抑制效果,對豬胰臟與黃豆澱粉?的抑制效果則小或無,此種抑制特異性深具害蟲防治的潛力。經由溫度與pH 的試驗發現粗萃中的澱粉?抑制劑成分應為蛋白質。我們以四季豆作為繼續研究的對象,將粗萃進一步純化,經由陰離子交換與膠體過濾層析,分離出單一蛋白質,經蛋 白質定序比對確認其可能為國外發表的腰豆澱粉?抑制劑—αAI-1。經由測試發現此抑制劑在 85℃時仍能抑制果蠅澱粉?,為一相當穩定的蛋白質;且抑制劑的作用受pH 值影響很大,在偏酸性環境下的效果最好,與昆蟲分泌澱粉?的部位亦為酸性環境有相當密切的關聯;且其 抑制作用具特異性,可明顯抑制果蠅、入侵紅火蟻、白蟻、蟑螂及麵包蟲等昆蟲的澱粉?活性,對人類唾液、豬胰臟、四季豆本身及黃豆澱粉?的抑制效果很小或無,值得繼續深入研究。 Plant amylase inhibitors can fight against predation from plant-eating animals. It has been reported that several amylase inhibitors have an obvious effect on pest control; among them that from Phaseolus vulgaris got the most surveyed. 5% T.C.A was employed to make crude extracts. We have screened the amylase inhibitor activities from crude extract among beans common in Taiwan. The inhibitors from both string beans (the different strain of Phaseolus vulgaris) and cowpea notably inhibited the amylases in Chrysomia megacephala, but little or no inhibition in porcine pancreas and soy bean. This specific inhibition behavior suggested strong potential in pest control. Its activity can be affected by temperature and pH suggested that amylase inhibitors in crude extracts should be proteins. String beans were chosen to be further purified from the crude extracts. A single protein was isolated after ion exchange and gel filtration chromatography. Through protein sequencing, the partial amino acid sequences were highly homologous to that ofαAI-1 from Phaseolus vulgaris, indicating it might beαAI-1. The purified protein still can inhibit the amylase from Drosophila melanogaster at 85℃, suggesting it is thermal-stable. Its activity was affected by pH and reached the peak in weak acidic environment, which might be related to the fact that amylases are secreted in acidic environment of insect’s midgut. It obviously inhibited the amylases from D. melanogaster,Solenopsis invicta, Odontotermes formosanus, Periplaneta Americana Linnaeus, and Alphitobius sp., while not to human saliva, porcine pancreas, soy bean and string beans itself. The unique pattern of inhibition activities of the purified amylase inhibitor was worthy of further anlysis.
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.