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磁流體的浪潮-磁場梯度下磁流波紋之研究

在本次實驗中,我們發現在不同厚度的磁流體薄膜中,會因本身磁性粒子結合,而呈現不同的影像圖形。隨著薄膜厚度增加,其磁性粒子會由鏈狀排列成塊狀叢集,可是一旦外加磁場後,又要全部轉向磁力線方向集結。另一個發現是將磁流體薄膜放在一個不均勻的磁場梯度中,則樣品內的磁流體粒子,不僅會隨著磁力線的方向排列移動,更會出現磁流波紋,其行進路徑是沿著垂直於磁力線的方向,向磁力線密集處移動。我們亦發現在不同的薄膜厚度及不同外加磁場下,其”磁流波紋”的波速亦會隨之改變。一般而言,樣品的厚度愈厚,或外加磁場愈大,其”磁流波紋”的波速愈快,反之則愈慢。最後,我們列出了一些磁流波紋的應用,相信是精采可期!In this experiment, we find that in different thickness of magnetic fluid different images will appear, because of the connection of magnetic particles. With the increasing of thickness the magnetic particles will change its shape from chains to blocks. But when we add external magnetic field, they will get in line one by one to the direction of magnetic line of force. We also find that we put the magnetic fluid film in the uneven magnetic gradient, the magnetic particle in the sample not only follow the direction of magnetic line of force but also show the “magnetic wave”. Its move path is perpendicular to the direction of magnetic line of force. In the different film thickness of magnetic field, the wave velocity of the “magnetic wave” will change. In generally, the thicker the sample is, or the larger the magnetic field is, the faster the wave velocity of magnetic wave is and adverse is true. At last, we list the applications of “magnetic wave”, we believe they are marvelous!

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黏度大考驗—應用具有黏性物質製作黏著劑之探討與研究

取四種黏性較大的食物:蓬萊米、圓糯米、中筋麵粉、太白粉,對這四種物質黏性的大小\r 加以研究和探討。一、因為實驗的需要製作二個簡易的地震儀,藉著馬達帶動熱熔膠產生不\r 平衡的現象讓實驗平台上下震動、左右搖晃,比較這四種食物黏性大小。二、探討這四種物\r 質加上不同比例的水時哪一種物質黏性較佳?三、將實驗試體加上不同比例的添加物探討黏\r 性的大小。四、在試體乾燥過程中,觀察試體縮水、變形和發霉的情形。五、對黏性最佳的\r 幾個試體做耐水性實驗,找出黏性佳又耐水的試體當做黏著劑建造拱橋。六、探討乾燥天數、\r 溼度對試體載重的影響。

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七巧板與多邊形

一年級上學期上數學課時,老師曾教我們製作七巧板,還利用做好的七巧板來拼多邊形,當時大家排出了三角形、長方形、梯形、平行四邊形,還有人排出了五邊形、六邊形,但是過幾天又排不出來了。到第三冊數學上商高定理時學到了等腰直角三角形三邊長之比為1:1:,於是又想到:七巧板有五個等腰直角三角形,那麼是不是也可以由邊長的關係來考慮七巧板所排出的多邊形呢?我們把這個想法告訴老師,老師鼓勵我們動腦筋,想想看,還提示我們七巧板每塊的角度都是45°,90°或135°,可以把角度也加進去考慮,有問題再來找老師討論,於是我們就開始著手研究。

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Heart‧Secret~探討讀心術的密碼

本研究起自於玩「吉普賽人讀心術」電腦遊戲所引發的問題,配合數學「整數的簡化計算」、「因數和倍數」、「怎樣列式」單元,來探討讀心術的設計原理,並嘗試設計自己的讀心術。結果顯示:一、「吉普賽人讀心術」是以 9 的倍數來設計。二、不同的讀心術設計原理不同,但都和整數的簡化計算有關,也和倍數有關。三、設計自己的讀心術遊戲時,需考慮玩家的計算步驟不能太複雜,設計者必須有快速的步驟猜中數字。

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利用浮沈子測量液體表面張力並演示"Cheerios Cheerios effect"

密閉容器置入待測液,放入浮沉子,施加壓力,當浮沉子恰要沒入液中瞬間,因表面張力的總力達極大值且向上,外加壓力(p1)為極大值,浮沉子沒入液中;液面減壓,當浮沉子在液面正下方時,外加壓力 p2,量 p1、(p1- p2),浮沉子的質量 m,外半徑 R,及玻璃管的體積 G V ,可求得液體表面張力。 液面再減壓,浮沉子恰要露出液面時,表面張力的總力達極大值且向下,外加壓力(p3)為極小值,量 p3、(p2- p3),浮沈子的質量 m,外半徑 R及 G V ,應亦可求得表面張力;但實驗時浮沉子漂移到容器邊,並吸附在器壁上,因此發現浮沉子的”Cheerios effect”。 利用浮沉子和容器的相吸及相斥現象,可解釋西式早餐的小榖片放入牛奶中為何會漂移到碗緣,並支持 Vella在 2005 年 9 月份美國物理期刊(AJP)認為 Cheerios effect的成因除了由於接觸角不同外,浮力、重力、表面張力共同作用,使小榖片間有相吸、相斥現象。 The experiment apparatus is equipped with a Cartesian diver by using a glass tube with air trapped inside that floats or submerses in a closed vessel containing liquid. The external pressure may be varied with a syringe and measured with a water manometer. The maximum pressure P1 inside the vessel is measured when the diver is just about to sink, where the surface tension that acts on the diver is upward. Then the pressure P2 of the vessel is measured when the diver is just beneath the liquid surface, where no surface tension acts on the diver. Finally, the surface tension is calculated from P1, P2 and the radius of the diver, R. When the pressure inside the vessel is decreased, the diver will rise. As the diver is about to emerge from the liquid, we get the minimum pressure P3 inside the vessel, and the surface tension that acts on the diver is downward. By measuring P3, P2, and R, the magnitude of surface tension is found to be the same as above. When the diver is just about to sink into the liquid, it floats to the center of the vessel. When the diver is about to emerge from the liquid, it sticks to the wall of the vessel. This phenomenon is named the “Cheerios effect.” Our results again strongly support that the cause of the effect is due to the different contact angles between the diver and water, as well as the balance of gravity and surface tension in the case of the sinking diver, and the balance of buoyancy and surface tension in the case of rising diver as Vella claimed in his paper (AJP 73, 817 (2005)).

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M24WS2 (Multiple Mode 4 Wheel Steering System)

\r The idea for my steering system started from a discussion with my Tech teacher about a wheel the Mechatronics and Robotics Research group of Massey University were working on. It featured precision shaped rollers at 45 degrees to the wheel’s axle. The idea was that with a number of these wheels a vehicle could go in any direction, depending on the rate that each wheel was revolving. \r

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鹽橋的種類、濃度、溫度對電流的影響

在國中第三冊 14-3 的實驗裏,提到鹽橋的濃度為 0.1M ,且使用強電解質。我們知道強電解質是因其具有幾乎完全解離的特性,故一般皆用強, KNO,且在室溫下操作,難道各種濃度的強電解質不能使用嗎?其效果又是如何?因而請教老師,並進而尋求解答的實驗。

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搖滾的秘密-讓音樂進入電的世界

?音器是一般電吉他重要的?件,它?用弦在其上方振動,而產生微?的信號給?叭,產生電吉他獨特的聲音。首先,我們製作簡?的單弦?器?模擬電吉他,接著著手研究把有可能影響電吉他發出信號頻?(音調)、振幅(音?)的變因一一找出各變因中對電吉他最有?的?態,做一把單弦簡?電吉他。

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哆啦 A 夢的空氣炮

本次的實驗探討寶特瓶空氣炮在不同的控制變因下,本實驗控制空氣炮的炮身長度、孔洞數量多少、瓶蓋孔徑大小、不同的氣球長度等因素,發現空氣炮所發射出來的威力範圍和形狀各有巧妙不同,後來也發現寶特瓶空氣炮在教育方面可以運用在科學遊戲上,比賽聲音大小、玩射擊遊戲等;在生活方面,可以運用在創意門鈴、創意喇吧、聲音密碼傳遞等。

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葉綠素電池之應用

植物行光合作用時,電子吸收光能後在能階上躍遷,形成ATP,藉此原理,利用葉綠素吸收光能後產生的化學反應,可製作出太陽能葉綠素電池。本研究主要針對萃取葉綠素之方式、葉綠素放置天數、電池電極與電解液之成分、電池的放置環境等變因進行實驗,根據實驗結果,葉子加入酒精後,以研磨方式萃取出的葉綠素再搭配碘液、鋁箔紙、碳棒,能做出電壓:1.136V 電流:0.4mA 電功率:0.4544mW的葉綠素電池。 葉綠素電池裝置的設計不只考量到裝置的可行性,對環境友善且永續也是很重要的考量因素,因此將會從下列面向進行研究:裝置如何防水、裝置的使用期限、裝置的素材是否環保,最後成功做出了一組環保的水上漂浮葉綠素電池,未來會再提高此電池產能並且運用在農漁業上。

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氣流式薄膜測厚儀

醫學上的植皮手術成功率受皮膚厚度影響,皮膚愈薄癒合速度愈快,其中以取皮厚度介於0.05mm 到0.1mm 為佳。在實驗量測時,需要經過一連串繁複的薄皮標本製作,再放到光學顯微鏡下測量,這種厚度測量方式不但耗時,又因嚴重損毀皮膚而不精確。由於使用螺旋測微器做接觸式測量會有形變的問題,因此我們想做間接接觸式的測量,所以採用氣體為媒介,做非破壞性檢測膜厚,這對於在皮膚上的施力遠小於螺旋測微器或是接觸式膜厚計。我們設計一套三頭連管線,使用空氣為媒介,儀器運作原理為在管線一端針頭非常靠近被測物時,所流出的氣體會受到被測物阻礙產生反壓使管線內的壓力上升,導致連通於另一管路的氣泡指示計壓出氣泡,當氣泡為最大氣泡時(半球形)視為達到平衡狀態。實驗時先用已知厚度且不變形的蓋玻片來當作被測物,此時可以算出針尖至蓋玻片的實際距離做為參考值。在量測軟性薄膜時,設計上採用兩側雙針頭靠近軟性被測薄膜兩側以達到氣流氣泡平衡,這時使用螺旋測微器讀取兩針尖距離,減去已知參考值的兩倍距離,即可測出未形變的軟物質厚度。本研究開發一套能測量軟性薄膜的厚度裝置,尤其在皮膚厚度測定上,不但不會直接接觸標本造成損毀,並且能夠快速地測量出厚度值,此為本儀器的最大特色。The thickness of skin graft has deterministic influences on the success of graft surgery. Experimental measurements of skin graft thickness involve complicated specimen preparation processes followed by optical microscopic examination, which are time-consuming and may incur inaccuracy due to possible damage. Here we propose a novel method using air as the media to avoid direct contact of the measured object. The physical operation relies on the following principles: When the tip of a needle connecting to a catheter system is placed close to the object to be measured, the air pumped forward from the catheter system becomes impeded by the object. The resulting backflow pressure opposing the air flow causes an increase in air pressure within the catheter and inflates the bubble connected at the other end. Balance at maximal surface tension is attained when the bubble reaches its maximum volume in hemispherical shape. In practice, a two-needle design was used, each approaching simultaneously from each side of the object. A micrometer was then used to read the distance between the two needle tips, from which the film thickness was derived, subtracting the thickness of the air layer pre-calibrated using cover glass with known thickness. The system implemented was capable of measuring thickness on soft thin films with an accuracy of ± 0.001mm. In addition to rapid measurements with high accuracy, since the pressure exerted on the skin graft is much less than in conventional calipers requiring direct contact, our method has the unique non-distorted and non-destructive advantages.

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黏黏有魚!魚鱗灰取代水泥砂漿試體試驗

「黏黏有”魚”!魚鱗灰取代水泥砂漿試體試驗」是將魚鱗灰取代部分水泥測其對抗壓強度和抗拉強度之影響,進而瞭解魚鱗灰是否可以取代部分水泥,將其廢物利用,並達到綠建築永續之主旨。同時降低建築工程材料成本並提高經濟效益。前期試驗用未燒結之魚鱗粉,但抗壓強度表現不佳,分析後發現魚鱗內含膠原蛋白對水泥強度並無預期之幫助,因此將其燒結成魚鱗灰,成分為無機磷酸鈣鹽類,實驗結果顯示磷酸鈣對其抗壓強度及抗拉強度都有較佳之幫助。若能結合研發中心萃取膠原蛋白後,高純度之魚鱗灰利用於生醫,而回收廢棄之低純度魚鱗灰作為土木建築材料之利用,相信魚鱗灰水泥將為工程材料史上一項創新材料,並賦與魚鱗回收再利用的新價值。

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