全國中小學科展

四等獎

液滴爆炸

本研究探討乙醇水溶液液滴於疏水流體表面之分裂現象。此現象可利用揮發造成乙醇之濃度梯度所驅動的表面張力梯度來解釋,此現象又稱為馬倫哥尼效應(Marangoni Effect)。液體為達到最低表面能而改變表面積的普托瑞立不穩定現象(Plateau Rayleigh Instability)也可以做為液滴分裂的解釋之一。 在研究中,研究團隊發現溶液在油面上會隨時間分裂出子液滴,並對於最終子液滴的半徑與分裂現象分別進行定量與定性之探討。本研究於先遣實驗中發現乙醇水溶液濃度之臨界下限為65%~67%重量百分濃度,並以大於(含)此濃度之溶液進行關於乙醇濃度、溶液體積與油層厚度、油層黏度四項參數對於最終子液滴半徑、分裂時間、液滴最大擴散半徑與擴散半徑演變之影響,也針對與參考文獻所選用液體不同深入探討異丙醇與乙醇的蒸發速率的差異如何影響實驗結果。

EVALUATION OF THE SURFACE TENSIO, LARVICIDAL AND ANTIBACTERIAL ACTIVITY OF PLANT EXTRACTS FROM THE LEAF OF THE ARACA TO COMBAT THE PROLIFERATION OF THE Aedes aegypti MOSQUITO IN STILL WATER CONTAINERS

The Aedes aegypti mosquito is one of the main transmitters of viral diseases in countries close to the equator. This vector promotes a series of generalized endemics that are difficult to control and prevent in these regions. Furthermore, the presence of bacteria in the environment favors the proliferation of mosquito larvae, which increases the probability of Aedes aegypti reproductive success. The Araçzeiro (Psidium guineense Sw.) is a plant present throughout the Brazilian Atlantic Forest and has in its composition, especially in the leaves, several substances that can be used to solve problems. Thus, we sought to verify the activity of flavonoids and polyphenols in terms of their antibacterial potential and the performance of saponins in their larvicidal potential, as well as surfactant, in order to prevent the accommodation of the mosquito in the water at the time of egg deposition and larvae respiration. The saponins were extracted from the araçazeiro leaf using a hydroalcoholic solvent and the flavonoids/polyphenols using methanol, the latter being subsequently rotaevaporated to maintain the non-toxic nature of the extract. Through the aqueous extracts, the content of total saponins by UV-VIS spectrophotometry, surfactant activity, larvicidal activity and toxicity were determined. In relation to the ethanolic extracts, the content of polyphenols and total flavonoids by UV-VIS spectrophotometry and high performance liquid chromatography (HPLC), antibacterial activity and toxicity were determined. The results showed that the aqueous extract has a satisfactory amount of saponins, as well as a surfactant potential due to the formation of foam and larvicidal activity in the two highest concentrations of the extracts. Ethanol extracts showed phenolic acids, especially gallic and ellagic acid, and flavonoids, especially catechin and quercetin, and antibacterial activity in most of the worked concentrations. Both extracts (aqueous and ethanolic) showed a dominant nontoxic character, which favors their use without risk to the environment, having an alternative and sustainable potential for controlling the proliferation of the Aedes aegypti mosquito.

選擇相對論-研究零元效應與需求強度關係

「零元效應」所指的是消費者面對同類性質之高低價兩商品,當低價商品從原價降至零元,而高價商品同時等量降價時,消費者對低價商品之偏好將顯著增加,並且因確定性效應、損失規避及稟賦效應造成。研究目的驗證零元效應的強度與成因,設計實驗零元效應於不同消費領域、族群是否皆成立;設計兩種商品,A為高品質高價位,B為低品質低價位,兩種定價情況,定價情況1,A商品為A元,B商品為B元,定價情況2,A商品為A-B元,B商品為B-B元(零元)。實驗結果使用Wilcoxon 等級和檢定,以需求光譜進行分析,並與 Dan Ariely (2007) 實驗結果進行比較,發現其差異不大;結果發現受試者身分不影響零元效應存在,除「必需品」外,其他品項皆存在零元效應,並且發現零元效應的強度受需求強度影響,若需求越強,零元效應將越弱。需求遂受試者環境影響改變,故不同國家將有不同結果。

朽木生花-初探以中藥萃取液對木材染色之防蟲抑菌效果

In our experiment, we used traditional Chinese medicine to dye on cheap wood, in addition to avoiding the impact of chemical paint on human body; After dyeing, the color and texture quality of the wood are improved, which makes cheap wood have higher price and improves the value of wood; At the same time, it can reduce the felling of slow growing precious wood, which has the functions of environmental protection, earth love and carbon saving. The test material was pretreated with hydrogen peroxide and surfactant, and the bleaching effect was obvious. After dyed with different Chinese medicinal, soak in strong acid and alkali solution for 15 minutes, which shows that strong acid and acid treatment is not allowed. On the other hand, after 15 minutes of immersion in detergent, the color difference value is less than 2, and the rubbing fastness is above grade 4. In the bacteriostasis experiment, no fungus grew in the first 3 days, and it did not grow in the 12th day. In the anti-termite experiment, the mortality rate on the fifth day was 65% for Lithospermum and 83.8% for Wolfberry, and the other groups had a good effect of total elimination. While plastic products have a great impact on the environment, wood that is dyed or modified with natural colored dye, its environmental value far exceeds the human visual perception.

合成二硫化鉬為基材之氣凝膠吸附環境毒性之含硫分子

由於經濟需求,人們對於農藥的使用量增加,若善後工作處理不當,易使汙染落入環境中,造成生態汙染及食安疑慮,因此本研究製作二硫化鉬奈米片作為選擇性的二維吸附材料,在過程中產生結構上的缺陷,進行化學反應吸附環境中的毒性硫化物。並使其摻混於氣凝膠中,應用於水溶液中去除常見的農藥—得恩地。 透過合成以二硫化鉬為基材的氣凝膠,在定溫定壓及pH值範圍恆定的前提下,我們分別以吸附時間、起始濃度作為操作變因,研究其奈米級二維材料與其氣凝膠之移除率、最大吸附量和恆溫吸附模式,並與活性碳比較後,發現二硫化鉬奈米片具有特異性之有效吸附,氣凝膠易於回收並可增進其吸附量之優勢,進而達到去除汙染物的目的。

搖頭擺尾 離子尾波形週期變化分析與原因探討

彗星離子尾受太陽風吹拂後,使其帶電粒子受力而改變噴發後的離子尾軌跡。C/2021 A1 Leonard的影像就可明顯看出它具有波狀的離子尾。我們透過影像軟體擷取彗尾影像的座標並將其代入分析軟體。依序分析2021年12月21日、12月31日與2022年01月02日的彗尾結構,利用不同的波函數擬合彗尾形狀並扣除擬合線,嘗試找出不同的彗尾結構是否具有相同週期或非週期的特徵。同一天內的不同離子尾去除穩定與漸進變化的週期後,發現具有相似形狀的變化區,應該為共同影響的非週期性因素,這個影響因素可能為太陽風的各種物理量(如:風速、磁場強度、質子密度等)。接著利用星圖軟體和數學幾何軟體推算出彗尾與其波結構的實際長度,並與太陽風資料互相比對。將三天的太陽風磁場南北分量(Bz)與各自的最後分析圖進行對照,發現兩者有高度相關性,推論太陽風磁場南北分量(Bz)的非週期變動是影響彗星離子尾不規則變化起伏的主因。

應用深度學習sequence to sequence model 於古文解譯

以將古文翻譯成白話文為初衷,以爬蟲擷取古文解譯網站「讀古詩詞網」中的大量古文及其白話翻譯作為訓練用的資料,並按照不同文體分開訓練。我們先嘗試用Bert模型做選擇題:給一句古文讓機器從四個選項中選出其翻譯。一開始隨機挑選其餘三個選項,正確率高達96%。因此我們挑戰更困難的設置,撰寫搜尋關鍵字的程式,將有與題目古文相同字的白話文放入選項。雖然準確率有些許降低,但仍高於只選重複字最多選項的結果,代表模型有發展出獨立的判定標準。選擇題成功後,我們用MT5 模型嘗試更困難的翻譯,並在訓練集中新增提供不同前後文的注釋資料幫助訓練。雖然還無法翻得非常準確,但仍在某些句子有不錯的表現。我們也發現了模型對某些特定類型字詞的翻譯有待加強,未來希望透過加強代名詞判斷訓練及持續新增注釋來增加整體翻譯能力。

即時觀測核苷酸調控單一DNA 分子上重組酵素的結合反應

在DNA重組反應中,核苷酸擔任輔助重組酵素E. coli RecA蛋白和DNA結合的重要角色,近期研究發現環狀核苷酸 Cyclic di-AMP 和Cyclic di-GMP是細菌內普遍控制複雜細胞活動的二級訊號,因此本研究運用單分子拴球實驗直接觀察單一DNA分子,以布朗運動值反映DNA長度的特性,分析環狀核苷酸參與調控後,重組酵素結合上DNA的反應速率與機制,進而了解環狀核苷酸在調節基因組穩定性的角色。 藉由分析單一種類核苷酸與混合核苷酸的實驗結果,得到兩種環狀核苷酸在重組酵素的結合反應中皆屬抑制劑,大幅降低蛋白結合上DNA的反應速率,且就結構來看,相較一般參與反應的三磷酸腺苷會增加DNA長度,新發現Cyclic di-AMP有縮短部分DNA長度的特質。 由於DNA修復主要倚賴DNA重組反應進行,因此若細菌DNA出現損壞時,加入環狀核苷酸抑制重組酵素結合上破損的DNA分子,使細菌DNA無法成功複製,達到預防細菌擴散的效果。

鑑色~藍染動力進行式

傳統藍染,染個深藍色的布,需要反覆侵染二、三十次才行,而每一次洗滌,都是藍水會對環境污染!我們自製鑑色儀器的設計,以白光照射吸光儀,讓光敏電阻感光後,測量一般電阻電壓大小,以不同濃度製作檢量線比較染液濃度;染布鑑色儀則是以GY-33顏色感測器校正後,快速測出色布上同樣區塊面積的RGB值,再利用線上顏色代碼轉換工具,轉換成HSB 值來分析染布顏色。而染布動力的部份我們想把一直都是用塑膠積木製作的二~六槳水車更新成金屬,然後再次比較出不同水位負載物的氧化及還原轉速,希望能找出最佳水車運轉速率及水位高度比,為了因應長度較大的藍巾,水車轉動還加入程式控制順逆轉軸的動力輪替。最後,我們比較增加風速或溫度可否加速藍染氧化之定色,讓精準快速的藍染文化成為可能。

以繞射光柵進行建物震動測量之探討

本研究利用光柵繞射原理,結合慣性振盪之單擺,探究震動造成繞射光點間距變化關係,以光點振幅測量震動,建立以光學繞射變動結果顯示結構震動之響應關係。先確定光柵片旋轉、擺角改變對於繞射光點位置偏移,並以GeoGebra軟體分析函數關係,接著測量實際結構震動之加速度與光柵繞射光點位置的動態變化關係,藉此分析地震造成建物擺動時,光柵繞射光點間距變動的關係與趨勢函數,並由訊號反應建立結構震動之繞射光點振幅變動的響應關係。以標準震動訊號產生平台,量化之振動訊號強度,測量出本研究裝置在二維平面之地震訊號測量之表現,獲得二維震動訊號方向分量之關係。並以OBSPY程式分析裝置所測量之震動頻譜圖,確認繞射光點振幅變動可顯示地震訊號之特徵頻譜,更進一步採用Python開發繞射光斑即時影像追蹤軟體,成功透過裝置分析環境的震動響應。未來希望能微小化裝置,以監測建物震動,作為區域範圍測量地震對建物影響之發展基礎。