搜尋結果
查詢 共找到 14338筆。 如查無相關資訊,可至 進階搜尋 進行查詢
熱門關鍵字: the king 水果 豆漿 電腦
科展作品檢索

Building Bridges with Water-The Floating Waterbridge

This paper describes the investigation of a fascinating physical phenomenon called the “floating water bridge”. Despite the fact that water is undoubtedly the most important chemical substance on earth, it is practically ubiquitous and it still represents one of the best explored substances, still not all characteristics are well-understood. There are some phenomena like the “floating water bridge”, which cannot be explained. If high voltage is applied to two beakers, which are arranged close to each other and which are filled with deionized water, a connection forms spontaneously, giving the impression of a floating water bridge. For the experiment discussed in this paper, two beakers with a diameter of 50 mm and a height of 80 mm are filled with triply deionized water. Platinum electrodes are submerged in the center of the beakers, one set to ground potential (anode), the other one on high voltage, up to 25 kV dc. Within the scope of this work, an experimental setup was developed, which enables measuring and demonstrating the most important parameters like voltage, current, length and temperature of the water bridge as well as the mass transfer between the beakers. In addition the correlation between the different parameters and the influence on the water bridge could be estimated. Once the beakers are separated, the bridge remains stable for several hours up to a length of 2.5 cm. With platinum electrodes and no electrolysis observed, a small current (≈300µA), a mass flow from anode to cathode and forces were measured. Pictures, taken with an infrared camera and a new developed method to record "infrared-videos", enabled to visualize the heat flow in the water bridge. Furthermore the conversion of energy and the dependence of charge and mass transfer could be estimated roughly. In the course of the investigations it was also tried to prove the water bridge with other liquids like castor oil, olive oil, a mixture of glycol and water as well as tap water - for some of them for the first time. Supplementary the experimental setup was varied by using different electrodes with different sizes and different material as well as beakers of different sizes and materials. In addition, a qualitative explanation was developed. The results of this work enable a better understanding of the floating water bridge and provide a basis for further research as well as for development of future practical applications. One of these applications could be an improved waste water treatment process.

> 更多

科展作品檢索

轉譯在延長階段所做的調控

高中生物課本內對於轉譯機制所舉的例子,通常僅侷限於轉譯起始階段(initiation)所受的調控,例如色胺酸調控組。因此,我們想藉此研究更進一步探討:細胞在不同階段是否有調控轉譯的現象。我們利用冷光蛋白測定法(luciferase reporter assay)測出CPEB3的確對於轉譯有減緩的效果,並利用不同internal ribosome entry site(IRES)間接證明轉譯速率的變化主要是根據延長階段的不同而有所改變。另一方面,我們將多組CPEB3突變株進行交叉分析,找出cpeb3序列中兩百多個鹼基對的重要基因片段,並發現其為不連續的基因,且用Co-Immunoprecipitation(Co-IP)驗證我們的實驗結果。未來,我們將繼續探討在延長階段抑制的意義,以助於我們進一步了解細胞轉譯的過程。

> 更多

科展作品檢索

「游泳池救生員最佳設置位置問題」之探討及其延伸

> 更多

科展作品檢索

雲林縣人口老化空間分布之探討

因雲林縣為全台人口老化最高的前三名之一,我們為了瞭解雲林縣人口的概況與各鄉鎮老化的差異,藉由分析人口資料,並利用地理資訊系統軟體進行空間分析,結果發現雲林全縣已達到超高齡社會,過去近15年來,幼年人口逐年下降,而老年人口的比例逐年上升。除了斗六、虎尾和麥寮等鄉鎮,幾乎所有鄉鎮老化指數都超過100。各鄉鎮人口特徵可分為數群,其中斗六為一群,虎尾、斗南、西螺、北港為較相近一群,而其他鄉鎮則為一群,各年度差異不大,但麥寮在近年則往虎尾群靠近。各鄉鎮醫療院所的分布與人口密度、工商活動聚集有關,反而和老化程度成反比,使得雲林縣面臨超高齡社會時,偏鄉地區的醫療照護將是相當險峻的問題。

> 更多

線上教學資源

從化學的材料本質思考循環經濟

> 更多

科展作品檢索

尋找冰寶寶收容所---保冰器DIY

本研究從探討在相同溫度與開放無加蓋的條件下,做不同材質的容器與冰塊融化速度快慢的比較。再將求得最好的材料,增加一個新材料---遊民寒冬裡最佳禦寒用具--「報紙」,來做更進一步的保冰效果實驗,果真求出環保又便宜可供做「保冰器DIY」的兩種材料。在愈見暖化的現代環境下,以後夏天可想而知一定會很酷熱的。所以為了便利又能符合節能減碳的前提下,我又查閱各方面書籍資料,得到一個容易、省錢又有效的「冰寶」製作方法。實驗下,加了冰寶的保溫效果果真如虎添翼。夏天出遊所需的「保冰器」,或是臨時需要「保冰器DIY」來保持食物冰度和新鮮度的時候,請跟我這樣做,就成了!

> 更多

科展作品檢索

海鱺血清對海鱺鰭細胞成長的影響

本文以動物細胞培養方法探討Leibovitz medium L-15培養基中以海鱺血清取代胎牛血清來培養海鱺鰭細胞株(CF-2)的可行性。結果發現L-15培養基中以0%、50%、75%、87.5%及100%海鱺血清取代胎牛血清濃度來培養海鱺鰭細胞,24小時後其附著率分別為51.9%、51.9%、54.6%、26.2%及24.0%;附著細胞中含破損細胞比率亦隨著海鱺血清濃度提高而增加。以同樣條件(缺取代87.5%組)培養海鱺單層細胞,6天後計算細胞數目,發現其細胞數分別為最初細胞數的4.16、10.84、11.84及9.2倍。這些結果說明海鱺血清中雖具有影響CF-2附著的因子,但也含有促進CF-2增殖的因子。CF-2細胞過馴化後可例行培養在L15-1.25/8.75培養基,顯示海鱺血清具有大量取代胎牛血清來培養魚類細胞株的潛力。

> 更多

科展作品檢索

果凍多色?我知道!—探討光在不同型態介質下的反應

五年級學到透鏡單元時,知道光經過透鏡折射可以矯正視力。為何透鏡能讓光線偏折?實在讓我們想不透!如果要製作各形式玻璃實驗,這技術實在困難。後來看到透明果凍,突然想到,如果用來代替透鏡,不就能控制厚薄、濃度、顏色及透光度。於是便開始設計實驗,解決想知道的疑問,而從實驗中我們發現: 1.紅、綠、藍、白光對各硬度、厚度、顏色、濃度、密度果凍的透光與折射程度都不同 2.利用三色光,對各顏色果凍的透光度,發明了全彩色光分析儀與全彩比色器 3.利用三色光,對各顏色果凍的折射率,發明了光折射率測量器、雷射測距與校準台沒想到小小的果凍,竟然解決了我們對光的疑惑,實驗中還意外設計出許多有趣的發明,真可說是小兵立大功呢!

> 更多

科展作品檢索

心『慌蟻』亂

藉由校園常見的香草植物來進行區以實驗,利用課堂上學過的化學萃取法和香草汁液的特性分析,探討壓榨浸泡法、酒精萃取法和加熱煮沸法所取得的5%、10%、20%濃度的萃取液其驅蟻功效。實驗結果:1.香草植物汁液為酸性,濃度愈高氣味愈重的汁液其驅蚊效果愈佳,但時效不長。2.採用直接噴灑法會對黑頭慌蟻造成致死,尤其是酒精萃取法20%濃度的薄荷、尤加利、羅勒、薰衣草,一小時內達到95%~100%的速效致死率。3.純精油自然揮發法:僅使用5 滴測試時間20 分鐘,24 小時後致死率竟高達85%~100%。4.稀釋塗抹法:濃度愈高,防蟻時效愈長,薄荷、薰衣草、百里香、檸檬香茅精油優於其他組。依據實驗結果製作環保產品,如乳霜、香皂、香水、貼片……等,可應用在螞蟻出沒的地方。

> 更多

科展作品檢索

翻開東北角那一頁---和美一帶漸新統貝類化石排列方式和古水流關係之探討

This study tries to reveal how the velocity of flow influents the orientations and scattering patterns of the two-valve shells (we use Pecten in this study) during depositing processes by comparing the laboratory studies with the field observations. We learn from the laboratory experiments that the shells deposit at random directions when they are too crowded and are oriented to a certain direction when they are more scattered. We also find out that the shell fossils whose dorsal sides towards downstream with upward concaves are most likely to move. On the contrary, the shells whose dorsal sides towards upstream with downward concave are the most reluctant to move Examinations of the outcrop of the bedding of Pecten fossils, which are located near Long Dong, the northeastern tip of Taiwan, show that a lot of the shells settled along a certain direction and most of their concaves are upward. However, some of the shells with obvious orientation have downward concaves, which implies the depositional environments were under high current velocity. And the numbers of the shells whose dorsal sides are oriented to Northern East are about equal to those whose dorsal sides are oriented to Southern West. This result coincides with the results of the laboratory study. However, the experimental results can apply to the field analysis under certain assumptions.本研究就影響貝殼排列的水速作試驗,尋找水流和貝殼排列的關係,並和地層中實際的貝類化石做比較,藉以回推古老沉積環境。結果發現大量貝殼集中的情況下,貝殼間彼此的影響力會大於單純的水流沖擊;當貝殼較分散時,可以看出貝殼的頭部皆會一致朝向水流的來向作排列。而最適合移動的型態是凹口向上且頭部不朝水流來向的貝殼,而最穩定的型態是頭部朝水流來向的凹口向下貝殼。觀察實際地層,貝類化石大致上也有方向性的排列且正反面貝殼都有,可以推得當時沉積的水流大,故有足夠的動能讓貝殼重新排列。但由於試驗環境定和自然環境有所差異,仍有限制存在。

> 更多

科展作品檢索

Safety in the building

The purpose: is to protect the building against the fires\r The main idea: is an Automatic emergency exit.\r When fires happen, the smoking detector works, giving sound and light.(signals)\r Then the emergency Exist opens automatically.

> 更多

科展作品檢索

紙蛇轉出的大學問

老師說這整個實驗不僅我們能夠得到很多收穫,就連老師本身也學到很多,怎麼說呢?全班同學進行空氣流動的紙蛇實驗,每個人都發現蠟燭上的紙蛇都是向前轉動,而且全班都得到一樣的實驗結果(有的因為轉動大多圈而會回轉過來的不算),老師還特別介紹這是科氏力的現象:因為北半球的物體運動都會偏向右邊,所以空氣由下向上流動的時候,會造成紙蛇呈現逆時針的旋轉。 因為實驗很簡單,而且課程又少,所以下一堂課就利用西卡紙來製作不同的紙蛇(有三角形、四方形、 … … ),但也有不同旋轉方向的紙蛇,桔果科氏力現象破功了,這就成為我們科展實驗的導火線!

> 更多