全國中小學科展

2004年

多重電極並聯情況下交、直流電解水的比較研究

The temperature of the water was commonly higher and both of electrodes were oxidized during electrolysis by using alternating current, but the above happenings were only found at the positive electrode by using direct current. It can be explained by the principle of the microwave stove. The exchange of the current causes the water molecules to release heat. The strength and weakness of electrolytes, the length and width of the electrodes, and the frequency of the alternating current can affect the rate of electrolysis of water. Commonly speaking, the stronger the electrolyte is, the faster the rate of electrolysis will be. NaOH and HNO3 are strong electrolytes, but the amount of the gas is zero during electrolysis by using alternating current. Maybe both of electrolytes react with stainless-steel electrodes to form some kinds of protective layers to affect the conduction of current. When copper bars, carbon bars, and iron nails are used as electrodes, either the alternating current or direct current is used, the amount of the gas is very small. Maybe these electrodes react with oxygen produced during electrolysis to form oxidized layers to block the conduction of current. Long and wide electrodes produce more amount of the gas. The amount of the gas increases when the frequency of the alternating current increases. The longer the distance between electrodes is, the smaller the amount of the gas will be. The smaller the angle between electrodes is, the smaller the amount of the gas will be, too. When the number of multiple electrodes in parallel increases, the total amount of the gas almost increases. The amount of the gas is smaller at the farther electrode. The amount of the gas at the electrode at the same distance becomes smaller when the number of multiple electrodes in parallel increases. At the same voltage, the effective current of the alternating current is about 0.707 of that of direct current. So we can predict that the total amount of the gas elect rolyzed by alternating current must be about 0.707 of the total amount of the gas electrolyzed by direct current. When we used stainless-steel electrodes and the electrolyte- H2SO4, we found the ratio was about 0.4286. Maybe the system of the electrolysis of water doesn’t obey the ideal linear system of Ohm’s Law and some part of electrical energy is wasted by increasing the temperature of the water and the oxidization of electrodes. 交流電解普遍水溫較高且兩極都有被氧化現象,直流電解則只有正極有上述現象,可能是交流電有類似微波爐的原理,電流交替時造成水分子震盪發熱。電解質強弱、電極種類、電極長短粗細、交流電頻率會影響電解水速率:強電解質較快,但NaOH 、KNO3 雖是強電解質,在交流電解時,氣體產生量幾乎是零,這可能是他們與不銹鋼電極反應形成某種保護層而影響導電;以銅棒、碳棒、鐵釘為電極時,不管是交流電或直流電,氣體體積都很小,這可能是這些電極和產生的氧氣反應,形成氧化層阻礙了導電;長的和粗的電極氣體產生量較多;交流電頻率越大,則電解所產生的氣體量也隨之增加;電極之間的距離越大兩極的氣體體積越小;兩電極之間的角度越小,兩極的氣體體積越少;多重電極並聯的個數越多,總氣體體積約略越大,距離越遠的氣體體積越小,同距離的氣體體積隨並聯的個數越多氣體體積越小。在相同電壓下,交流電輸出的均方根電壓(電流)為直流電電壓(電流)的0.707 倍(1/√2),所以推測交、直電解水的氣體總體積比值也應為0.707,但我們以不銹鋼為電極、H2SO4 為電解液下比值為0.4286,這可能是本電解水系統並非為遵守歐姆定律的理想線性系統,且電解水時部分電能被消耗在水溫的升高及電極的氧化上。

聚苯胺製備改良及其在防蝕應用研究

導電高分子在各面之應用非常廣泛,其中聚苯胺因價格便宜,製作簡便,使其應用潛力更為突出。聚苯胺在鐵系及非鐵系金屬之防蝕能力已被證實,但由於聚苯胺與金屬之附著力不良使其應用受到限制。本文以提高聚苯胺在有機溶劑中溶解度以達到和金屬有效附著增加其防蝕能力為主,而奈米粒子所具有的表面效應、小尺寸效應及宏觀量子隧道效應,可為研究目標之一。但由於高分子奈米微粒之製備仍屬有限,故仍在研究中。 \r The development and application of the conducting polymer poly-aniline is getting\r prosperous and popular. The capability of poly-aniline in corrosion protection has\r been proved. But due to the adhesion of poly-aniline on the metal is poor, the applications\r are restricted. In this paper, the authors utilized how advance the solubility of\r poly-aniline in organic solution to modify the adhesion of poly-aniline on the metal\r in order to improve the effect of the corrosion protection of poly-aniline in ferrous\r metal. And the nanoparticles have the special effects such as the surface effect,\r the small size effect and the macro-quantum channeling effect. It can be an object\r for research.

磁性流體可調性折射率特性之研究與應用

磁性流體(magnetic fluids)是一種含有磁性奈米粒子的液體,當磁場外加於磁性流體時,流體中各磁性奈米粒子的磁矩會沿外加磁場方向排列,而導致粒子間相互吸引,形成較大的磁性叢集,即所謂的磁鍊。當外加磁場增強,該磁鍊數會變多,並使磁性流體的折射率產生變化。磁性流體的折射率變化會隨外加磁場之變大而增大。本研究除探討磁性流體折射率受外加磁場控制的變化情形及其物理原由外,並進一步運用此特性研發可調性光纖「光調制器」 ,以探討磁性流體可調性折射率應用在光電元件上的可行性。A magnetic fluid is one kind of colloids which contain magnetic nano-particles. Under an external magnetic field, the magnetic moment of nano-particles is aligned along the direction of the external magnetic field. This leads to the agglomeration of magnetic particles and to form magnetic clusters under an external magnetic field. With the formation of the magnetic clusters, the refractive index of magnetic fluid is varied. The refractive index of magnetic fluid was found to increase under a higher magnetic field. In this work, In addition to investigating in detail the behavior of the field-dependent refractive index of the magnetic fluid, we also explore the relevant physical origins. Furthermore, the feasibility of developing fiber-optical modulators by utilizing the tunable refractive index of magnetic fluids is discussed.

利用雷射光碟(CD)做光的繞射實驗

雷射光碟(以下簡稱CD)除了在電腦、音響方面有甚佳的視聽功能外,在光線照射下,呈現彩虹狀的光譜,必定引起你我研究其光學性質的興趣。國內以CD研究光的繞射的著作,有李偉等四人近三年發表五篇,國外科教期刊自1991年迄今共有19 篇,在老師指導下,利用CD進行了8 項實驗,分成三大項。1.利用氦氖雷射分別照射舊唱片、CD、DVD,反射光形成繞射現象,由dsinθ=mλ,量出槽距。2.將CD-R 的鋁層刮掉,(整疊購買的CD-R上下有數片未鍍鋁的瑕疵片),成為透光式CD(透射式光柵),將其中心半徑5.5 公分部份,用黑紙遮住,正對陽光,螺旋狀的溝槽將陽光聚成一點,量出各色光到CD的距離,可算出色光的波長。3.透射式CD置於投影機鏡頭前方,投影機置物台上,放置化學藥品,可直接在屏上觀察吸收光譜。The rainbow of colors reflected from the surface of an audio compact disc (CD) is a familiar sight.It is the phenomenon of light diffraction. A standard CD has 20,625 turns of the spiral, and each line is spaced by 1.6μm. This provides a grating of 625 lines/mm. We used ordinary CDs as reflection grating in our experiment,and transparent factory rejects with no coating but printed data spirals as diffraction grating. We conducted eight experiments of diffraction using the two kinds of CD. (a) Determined the grating spacing of an ordinary CD using a laser beam. (b) Determined the grating spacing of a transparent CD using a laser beam. (c) Studied the diffraction patterns caused by a laser beam held at angles to a transparent CD. (d) Measured the wavelengths of sunlight using a transparent CD. (e) Measured the wavelengths of sunlight using an ordinary CD. (f) Formed a rainbow using a transparent CD. (g) Observed the scattering of light using a transparent CD. (h) Demonstrated the absorption spectrum using a transparent CD and an overhead projector.

一滴溶液的顯微電解世界

Whe we think of chemistry experiments in schools from the view of environmental\r protection, microscopic chemistry experiment with reduced quantity and waste is\r the trend for experiments in the future. It is also the target that everybody shall\r aim for. After many failures and instructions from teachers, I finally successfully\r performed electrolysis of the most micro-volume of one-drop solution. It was also\r unbelievable to perform quantitative test within the electrolysis time of color\r disappear from the blue cupic sulfate solution. \r To clearly see the one-drop solution electrolysis, instrument starts from magnifier\r to self-assembled micro project, then upgraded to the miro-visual screen. It not\r only can record,also plays/shows in the computer. Most importantly, it is the most\r environmental protection effective and also zero pollution microsopic chemistry\r experiment. It is obviously a target of future development trend. \r 我們從環境保護的角度去思考常校的化學實驗時,減量減廢的微型化學實驗已是未來實驗的趨勢,也是大家應共同努力的目標。在多次失敗及老師的啟發下,我終於成功的做到電解最微量的一滴溶液。對於從藍色硫酸銅溶液顏色消失的電解時間裡,還可做定量的檢定感到不可思議! \r 為了更清楚看到一滴溶液的電解情形,儀器的設計由放大鏡到自組顯微投影機,最後進階到顯微視訊的畫面,它不但可記錄下來,而且可在電腦中播放。最重要的是:最環保也最接近零污染的顯微化學實驗,已然是未來可發展下去的目標。

乳酸桿菌及啤酒酵母之相互作用及其代謝產物對Clostridium difficile 生長之影響

市面上可以看到多種品牌紛紛推出了以“啤酒酵母”作為號召的乳製品,標榜健康取向\r 的“啤酒酵母優酪乳”也是其中的一件,我們蒐集了關於啤酒酵母以及乳酸桿菌的文獻,打\r 算研究之間的關係,乳酸菌屬於益生菌,主要的用途是製作優酪乳,可以協助維持體內正常\r 的腸道菌相,降低血清膽固醇以及預防骨質疏鬆症(Rolfe, 2000);啤酒酵母最主要的用途為\r 啤酒的製作,具有解決失眠、消除疲勞、改善痢疾的功效。外國的克芙爾(kefir)也是屬於含\r 有乳酸桿菌及酵母菌菌相的食品,而且也對健康有益。因此我們提出了一個問題﹕啤酒酵母\r 與乳酸桿菌的代謝產物是否有著互利的功效呢?在拋出第一個問號後我們繼續尋找資料以\r 及著手我們的實驗。在文獻中(Gaon et al.,2003;Corthier et al.,1992,1986)也曾經提及啤酒酵\r 母與乳酸桿菌對於Clostridium difficile 所引起的偽膜性腸炎的關係,所以使我們又想問兩個\r 問題:究竟Ampicillin 對於乳酸桿菌、酵母菌、C. difficile 的影響有多大?而乳酸桿菌及酵\r 母菌對於C. difficile 的影響又是什麼?

磁流體薄膜在磁場與電場下之繞射現象

本實驗主要是探討磁色效應,光通過狹縫會產生繞涉現象產生繞涉圖形,為了要了解繞涉現象,要先瞭解光柵的結構。要探討光柵,就要先探討探討磁流體的結構結構,磁流體乃是將一般磁性物質製成小粒子,再使其懸浮於非磁性液體中,根據統計力學,只要粒子夠小,就可經由布朗運動均勻散佈在溶液中。而散佈在溶液中的磁性粒子會因為磁力及凡得瓦力而聚集,所以一般都會在小粒子周圍覆蓋一層介面活性劑,防止發生『沈澱』的聚集現象。磁流體具有磁性特徵及流體特徵,磁性特徵是磁流體的居禮溫度和一般鐵磁固體相當,而且在外加磁場時磁性顆粒會連接成磁柱,而流體特徵則表現在其具有各式各樣的、流動性、黏滯性、揮發性、飽和性及導熱性。我分別將磁流體薄膜在加入不同磁增率的磁場、不同大小的電場、混入液晶等的狀態下,做各種的光柵樣本。接著再打入平行光,觀察繞涉圖形,其中加入磁場的,磁性顆粒會連接成磁柱,縱切面會形成點狀的六角行有序結構,非常適合做光柵,繞涉圖形是一七彩圓環。加入電場的,並沒有規則的排列,沒有如加上磁場般有規律的變化,但是觀察到很多磁性顆粒的擾動和聚集,還有電極邊界的一些變化。而加入液晶混和均勻之後,為一個比原本顏色更深黑的流體,磁流體的粒子即固定不動,成黑色團塊混合乳白色的液晶,對電場磁場都沒有反應。就實驗觀察到的,我們發現了,最是合作光柵的是在磁場下的磁流體,而電場對磁流體的結構也有一定的影響,在探討光柵的實驗中,也觀察到了很多磁流體的特殊現象。

最佳振翅翼飛具--半活動翅骨翼之設計與測試

本研究的目的在於設計出一機械裝置,使振翅翼的升力比傳統的設計能更有效率的提升,並經由實驗證實此種機械裝置理論的正確性。在觀察有關鳥類飛行過程的錄影帶及尋找鳥類相關的資料且界定欲實驗的種類和現有的能力及資源後,本研究中設計出三種可行的振翅翼機械裝置,並進行在相同風速、相同振翅頻率(每分鐘振翅翼拍動144 下)的條件下,測試在不同振翅翼機械設計條件下的升力系數,在實驗中發現既有而廣泛的應用於玩具上的振翅翼設計與固定面振翅翼的設計,二者在拍打的過程中各有優缺點,而第三種的半活動面振翅翼設計,在拍打時能排除前者的缺失而同時擁有前兩種的優點。此種半活動面振翅翼機械裝置大大的提升了振翅翼的升力,且在設計上與現有的形式差異不大,若能更進一步的在機構上做更精密的改良設計,則將可大大提昇現有振翅機的性能。The study on the flapping wings with various angle of attack and different wing designs have been done. Three types of wing have been examined in a home-build wind tunnel . One is a membrane wing with fixed leading-edge support, the second is a membrane wing with both fixed leading-edge and fixed-web support , the third wing is a membrane wing with fixed leading-edge support and half-free-joint web support , with varions web length and web curvature under different angle of attacks , the wind tunnel testing results show that the half-free-joint web support membrane wing with fixed leading-edge can offer a much higher lift coefficient . It is suggested that the third type wing is the best choice for designing the future flapping wing vehicle.

月亮太陽斜斜掛

In this project, we mainly employ the self-made “positioning system for celestial objects” (PSFCO) to investigate the relations among Sun, Moon, and Earth. Based on the observational data, we then construct a three-dimensional (3D) model to further understand the hidden mystery. We first use the PSFCO, which was developed through four generations (see figure 1), to measure the change for a whole year in the North Polar Distance (NPD) of Sun and Moon individually. From the data analysis, we find that: 1. This change in NPD is very close to a sinusoidal function. 2. The date when the NPD of Moon is the largest in a month shifts earlier by 2.26 days every month on average. 3. The angle between the equatorial axis (EA) and the lunar orbital plane (LOP) is about 63.5 degrees, while the angle between the EA and the ecliptic plane (EP) is about 66.5 degrees. 4. The angle between the LOP and the EP is about 5 degrees. This is exactly why the solar eclipse and the lunar eclipse do not happen every month. 5. Time for a celestial object to be above the horizon = 1080 minutes – 4 (minute/degree) x NPD of the object. We geographically prove this empirical formula. With this formula and the PSFCO, we can accurately predict the times when an object rises and sets. We finally make a 3D model for Sun, Moon, and Earth. In this process, we confronted and then solved several difficult questions in mathematics and astronomy. This research dramatically enhances our understanding in our local planetary system. 主要利用自製的“天體定位儀”來詳細探討月亮、太陽及地球之間的位置及軌道關 係,並藉由三度空間模型的製作來進一步了解其中的奧妙。 首先利用天體定位儀 (共研發出四代,見圖1) 來量測月亮及太陽各自與北極的夾角 在1 年內的變化,經數據分析發現: 一、這個變化很像sin 函數。 二、月亮與北極的夾角發生極大值的農曆日數,每月平均提早約2.26 日。 三、白道面與赤道軸的夾角約為63.5 度,黃道面與赤道軸的夾角約為66.5 度。 四、白道面與黃道面之間的夾角約為5 度。這正是日蝕及月蝕不常發生的主要原因。 五、天體在地平線上的時間(分) = 1080 分-4(分/度) x 天體與北極夾角(度)。我們用幾 何定理證明了這個觀測到的關係式,且配合天體定位儀可準確預測任何可見天體 升上及落下地平線的時間。 最後製作月亮、太陽及地球的3D 軌道模型。過程中遭遇並解決了各種數學及天文 難題,使我們對這個行星系統有了更深一層的認識。

攀蜥,攀棲-由台北市內湖金面山區生態因子分析夜晚黃口攀蜥之停棲策略

For this research, the nocturnal perching habits of the lizard, Japalura Polygonata Xantbostona, were examined. Nighttime observations were made from July 2002 to March 2003 in the area along the mountain brook in the south valley of the King-Mien Mountain in Nei-Hu District. The study comprised a series of analysis with discussion of the lizard’s (Japalura Polygonata Xantbostona) perch based on the temperature of living environment and the manner of perch including the dissimilarity between male and female, adults and juvenile lizards in selecting their perch conditions. During the period of study 452 lizards were marked and examined. 163 were female, 168 were male, and 121 were young lizards. The study considered four particulars: (1) orientation, (2) angle, (3) manner of perch, and (4) height of the perch above ground. As for the orientation, most of the lizards chose to perch in an inward (towards the tree) and in an upward direction; the angle of perch was mainly within 1°~ 45° and slanted to 180°. Second, the manner of perch chosen by most of the lizards was holding the stem or trunk by arms. All four groups of lizards exhibited no difference in the orientation, angle and manner of perch. However, male lizards tended to perch at a greater height above ground than the female and juvenile lizards did. The study produced other findings as well: A tendency correlation curve was plotted showing that temperature related with the number of lizards taking perch, and from the curve the optimal temperature of the living environment was determined to be approximately within the range of 19° ~24°. Additionally, there was a relationship between temperature of living environment and the size of lizard and the number of lizards taking perch. A further positive relationship was observed between temperature and the height of perch above ground. Also, the study showed an apparent positive relationship between the temperature of sample living area and the snout-vent length(SVL) of the lizard. Finally, the Japalura Polygonata Xantbostona tended to take their nocturnal perches within a rather fixed home range. 本研究由2002 年7 月至2003 年3 月,於臺北市內湖區金面山南麓溪谷進行黃口攀蜥夜 晚停棲策略研究,以溫度和各項停棲行為進行來分析探討,包括黃口攀蜥的成幼蜥、雌雄蜥 停棲選擇上的差異。 研究期間,共標記到452 隻攀蜥,其中雌蜥163 隻、雄蜥168 隻、幼蜥121 隻。將停棲 的情況分為方向、角度、停棲型態、離地高度四項來分析,在方向上多以朝內、向上為主; 角度多以小角度的1°~45°及180°為主;在停棲型式多以環抱莖枝為主。進一步分析成幼蜥、 雌雄蜥不論在方向、角度、停棲型式的選擇上皆無差異。離地高度的部分則以成蜥及雄蜥的 停棲高度較高;以溫度分析黃口攀蜥的成幼蜥出現停棲隻次、停棲高度、出現停棲攀蜥體型 的相關性,溫度對出現停棲隻次可以做出趨勢相關曲線,估算攀蜥的停棲有一最適宜溫度範 圍約在19~24℃間;溫度與其停棲高度呈現正相關性;每次測得樣區溫度與出現停棲攀蜥平 均吻肛長有顯著的正相關。而黃口攀蜥夜晚婷棲時則會傾向於較固定的範圍內。