全國中小學科展

臺灣

無紫外光下的抑菌-可見光奈米光觸媒研發

In this experiment, we hope to produce appropriate-sized nano particles of by using the chitin. By mixing the particles with the metal of Ti, Fe and Zn of proper proportions and therefore narrow their band gaps. Thus, the Bacteriostasis of LightPhotocatalysts could appear under the environment where the energy is lower than ultraviolet ray. We use de-acetylated chitin in three ways -- chelating agent, surfactant and protecter. Then we put a thin layer of the mixture of chitin and metal nano particles on a piece of glass, and afterwards, sintering the mixture on the glass. Next, we scan the surface of the glass with AFM(Atomic Force Microscopy) to measure its particle size. The result we got showed that the surface-roughness of the Ti-Fe nano particles was 30.642nm, the best solution of all the samples. Yet, in this experiment, Fe was not suitable. Therefore we should choose the sample of Ti-Zn mixture, which is slightly smaller in roughness. According to the result we got from the experiment, we found that, under the yellow light, the survivable strain-number ratio of the sintered Ti-Fe-Zn mixture on the glass and empty glass was 0.09±0.06. This was much better than the survivable strain-number ratio of 0.17±0.06, the result we got out from the glass of pure Ti and empty glass. From the measurement, we found that the proportion of mixture could lower the excitation energy Ti needs. Through this experiment, we hope to create a layer of film containing nano particles, and by applying it to daily-use products, we could prevent harmful bacteria. 本實驗的目的,就是希望可以利用幾丁質製作出適當粒徑大小的金屬奈米顆粒,混合適當比例的鈦、鐵、鋅金屬,使其能隙變窄,讓我們能在低於紫外光能量的光譜下,產生奈米光觸媒的抑菌效果。筆者在實驗中利用去乙醯化之幾丁質在本實驗中扮演三種角色:螯合劑、介面活性劑及保護劑,以將幾丁質與金屬奈米顆粒均勻塗抹於玻璃上,並以燒結玻璃的方式進行實驗。並且利用AFM掃描玻璃表面,確認其表面尺度,驗證的結果Ti-Fe混合比例的奈米顆粒之表面粗糙度為30.642nm,為最佳狀態,但在本實驗中Fe並不適用,故應以粗糙度僅次於Ti-Fe的Ti-Zn混合比例為主。根據實驗的結果,在綠光下,混合比例的Ti-Fe-Zn玻璃與空白玻璃的菌落數比,菌落存活率為0.09±0.06,相較於純Ti的0.17±0.06來的低,代表混合比例可降低Ti所需之激發能量。經過此實驗未來筆者希望可以以幾丁質製作出一層含奈米顆粒的薄膜,應用到各種生活用品防止細菌的危害。

由溶氧量之變化分析單胞固氮藍綠藻光合韻律之特性

此項研究是用溶氧計連續偵測培養液中之溶氧量,藉以分析固氮\r 單胞藻RF-1 的光合韻律。實驗的結果清楚地看出RF-1 之光合韻律,\r 而且能夠清晰地觀察到其中光合作用、呼吸作用和固氮作用之間的相\r 互關係。研究中還發現:在不進行光合作用時,RF-1 的固氮作用也\r 會停止;另一方面,在有進行光合作用、但是停止固氮作用的狀況下,\r RF-1 光合作用之韻律現象會喪失。這些實驗結果值得未來更深入地\r 探討。報告中也包括了單胞藻PCC6803 的光合韻律實驗,藉以做為\r 有固氮能力與沒有固氮能力藍綠藻之間的對照。The variation of dissolved oxygen (DO) in the culture of the\r unicellular nitrogen-fixing cyanobacterium Synechococcus RF-1\r under diurnal light/dark condition was detected automatically by DO\r meter. The results indicated that the algae exhibited circadian\r photosynthetic rhythm. The results also revealed that a respiration\r rhythm occurred at dark phase when the culture was grown in\r nitrogen-free medium. There was correlation between the rhythm of\r photosynthesis and nitrogen fixation. The nitrogen-fixing activity\r could not be detected if the photosynthesis was stop by cultivated\r under continuous darkness. On the other hand, the rhythm of\r photosynthesis could not persist when the nitrogen-fixing activity\r was inhibited by NaNO3. In order to compare the difference\r between Synechococcus RF-1 and the cyanobacterium, which\r cannot fix nitrogen, the DO pattern of Synechocystis PCC6803 was\r also investigated.

台灣地區冷泉成因的實驗室模擬

本實驗是以實際探勘的地質及泉水資料和文獻為基礎,對於幾個可能造成冷泉降溫的原因(岩石種類、泉水pH值、流通氣體之壓力、流速)進行實驗。我們製作了一個模擬地下泉水流動的實驗管路,此管路並可同時觀察紀錄氣壓、氣體流速,以及實驗前後模擬管路的溫度變化。透過對實驗管路的熱容量校正,我們可以找出各變因對泉水降溫的關係,以建立出一個模型,期望可套用於實際冷泉的狀況,進而推論出更多冷泉的性質。This experiment uses data and bibliography from real exploration as bases to find the possibilities of why the cool spring drops in temperature. (Mineral types, spring water's pH value, air flow pressure, and movement flow.) We created a model of underground spring water for the simulation. From this model, we could observe the air pressure, movement, and the spring's change of temperature before and after the tests. By adjusting the thermal capacity in the model, we could find the direct cause of the spring's temperature drop. And hopefully be able to adopt this model to the realistic problem, increase the effort of analyzing the natural cool spring's properties.

低雷諾數圓形及多邊形水躍的研究

打開水龍頭,水鉛直落到正下方的水平板時形成圓形水躍。我們實驗研究20<Nr<150 的低雷諾數圓形水躍的變因,探討圓形水躍半徑和流量、出水口高度、以及液體黏滯係數間的關係。改用高黏滯係數的液體(4:1 的乙二醇水溶液),鉛直落入板上方深h 的相同液體時,先形成圓形,h 漸大時形成環形圓紋曲面,再加大h,形成多邊形水躍,內外圍同方向旋轉,轉速ω;液中加水,黏滯係數高於及低於某定值,多邊形都消失,側面觀察,外圍液體作鉛直面旋轉。將水平板改置於旋轉盤上方,使高黏滯係數(4:1)的乙二醇水溶液鉛直落入板上方形成多邊水躍,逐漸加快旋轉盤的轉速至 ω 時,多邊形都消失;逐漸減少乙二醇的濃度,至完全用水實驗,亦有多邊形出現,我們認為;平板上方的液體的轉動是非圓形水躍的成因。When a jet of water falls vertically on to a horizontal plate, it spreads out rapidly in a thin layer until it reaches a critical radius at which the layer depth increases abruptly. This phenomenon commonly called the circular hydraulic jump. We study the variations of the circular hydraulic jump radius, as a function of volume flow rate of the jet, the drop height, and the viscosity of the fluid at low Reynold numbers (20<Nr<150). When a jet of ethylene-glycol mixed with water (the kinetic viscosity is 10 times of water) falls on to a horizontal plate which is immersed in the same liquid with height h. We find the circular state frequently undergoes spontaneous breaking at its axial symmetry into a stationary polygonal shape. Rather than displaying the weak angular deformation generally seen in fluids, the jump forms clear corners and edges that are often straight. Several of these polygon formations show consistency in height h. And we find the polygon structure rotates in a horizontal motion. When a jet of water falls on to a horizontal plate, and the plate is rotated by a motor ,we find the axial symmetry of the free surface of circular hydraulic jump is spontaneously broken a various number of cornered polygonal shapes. We study the number of corners as a result of the volume flow rate of the jet, the drop height and the viscosity of the fluid in the experiment. And the frequency of rotation of the plate is taking into consideration.

以二極體汲發之 Nd:YAG 雷射之探討

Nd-YAG Laser 是目前最常被用來當作Pumping Source(汲發光源),較早期是使用discharge lamppumping,但是閃光燈的發光頻率並非完全落在Nd-YAG 晶體的吸收帶上,因此大量的能量轉變為熱能,十分的浪費能源,且增加冷卻系統的負荷。因為discharge lamp pumping 是一種氣體放電的過程,每次放電的時間和能量都有很大的不穩定性。所以高效率、高穩定性的Laserdiode 便成為pumping source 的另一種選擇。在此實用價值下,便決心以一組Laserdiode Pumped Nd-YAG Laser的套件,使用AlGaAs Laserdiode 作為pumping source,來汲發Nd-YAG 晶體,所有物件被固定在同一個rail(軌道)上,從對光到汲發晶體(增益介質Nd-YAG 晶體),到產生1,064nm 的紅外光雷射,及其倍頻532nm 的綠光雷射,正可作為一完整的雷射訓練過程。

心跳頻率之函數數學模型

本文我們研究下列問題: 1. 何時心律會成穩定的狀態呢? 2. 是否能建立出心律穩定的數學模型? 3. 什麼樣的函數會使得心律趨於穩定?我們以xmp+i 表示第p+1 個訊息傳到第i 個細胞之前,第i 個細胞的舒張時間,而且xk 和 xk−m, xk−m+1,..., xk−1的關係為 In this paper we study the problems as follows: When will the rhythm of heart beats approach to a steady state? Can we set up the mathematics model with steady rhythm of heart beats? What kind of function will make the rhythm of the heart beating tend to be stable? The result of our study is as follows:

奈米微粒現形記~化學反應速率的探索

In order to facilitate a paradigm shift from traditional high volume chemical experiments to an environmentally friendly microdose experiment; I had to innovate and overcome a lot of difficulties. After six generations of experiment design I successfully reduced the volume of the combined reactants to a single drop. I utilized many recycled components to build my apparatus including a vintage computer, a simple CD disk, optical sensors and a transistor from a common computer mouse. By using a CCD monitor with an external camera feed, the single drop chemical reaction can be observed in real time and a recording of the event can be made. I chose the focus of the experiment to be the reaction of sodium thiosulfate and hydrochloric acid to create a colloidal solution of sulfonium nanoparticles. By employing a custom-made transparency target to achieve a higher precision of measurement I have also conducted deeper research into the reaction order and the rate constants. 為了將傳統高劑量的化學實驗順利的推向顯微液滴的化學實驗上,今年我們更是創新突破了很多困難的關卡。 儀器設計由第一代減量研究到第六代的減量設計,目前已能成功的運用報廢的光碟片、報廢的電腦、報廢滑鼠內的感光二極體元件及電晶體來自製設計出兩反應物各一滴溶液做自動偵測反應的記錄。透過顯微鏡加裝的CCD電子螢幕目視觀看、拍成電子影片檔由電腦播放的目標。 因此,我選定了硫代硫酸鈉溶液和鹽酸溶液反應可產生硫奈米微粒的膠態溶液作為實驗的主軸及設計可較精確定量的投影片載液面,我們也企圖對其反應速率式的級數及反應速率常數做更深入的探討。

心手相連的正方形

正方形兩條對角線的交點(即中心點)距四頂點等長,也與四邊等距。如果將正方形的頂點比擬成它的「手」,兩對角線的交點當成它的「心」,則兩個正方形頂點間、中心點間、或頂點與中心點間的線段相連(或重合),就如同「手」或「心」彼此相連。本文即探索當多個正方形間「心手相連」時,衍生圖形間的面積關係。而四個正方形中某幾個頂點相接(邊未重疊),恰圍出兩個三角形的圖形則是本內容討論圖形的主體架構,我們以此架構向外作出「層出不窮」的正方形,再配合中心點連接成四邊形,將推導出這些四邊形與基準正方形(Reference Square)間的面積關係。In a square, the lengths from the intersection point (center point) of two diagonal lines to the four apexes are the same, and so are they from that point to the four sides. If the apexes are “hands” and the intersection point of two diagonal lines is the “heart” of a square, the connection or overlap of two squares’ apexes and apexes, center point and center point, or apexes and center points is just like the connection of hands with hearts. In this article, hence, we are to explore the relation in area of derivative graphs formed by several squares connected “heart in hand.” When some apexes of four squares are overlain without sides overlapped, two triangles are created. And that’s the theme we are going to discuss. Furthermore, we extend the operation to infinitely overlain squares and frame out quadrangles referring to the center points of some squares. Then, the relation in areas of these overlapped squares and the Reference Square would be deduced.

丹尼爾寶寶的酗酒日記--酒精對斑馬魚胚胎頭骨與腦下垂體基因的影響

長期以來,臨床研究發現酒精會影響人類胚胎的正常發育,但是其分子機 制尚不清楚。在本研究中利用RNA 定位雜交的方式觀察酒精對於胚胎發育過程 中shh、sox9a、sox9b、col2a1、hand2 的影響,發現這些基因的表現均會受到酒 精的抑制。這項結果顯示在胚胎發育過程中,酒精透過對上述基因的影響,造成 神經脊細胞減少,細胞遷移異常,以及干擾軟骨細胞分化的現象,進而造成頭骨 發育的嚴重缺陷。此外,實驗中亦發現生長激素在腦下垂體的表現亦受到酒精抑 制。這項研究的結果成功地從基因的層次深入了解胎兒酒精中毒症候群造成頭骨 畸形及生長遲緩的病理機制。 It was known that prenatal alcohol exposure may cause serious birth defects and developmental disabilities. The molecular mechanism of this fetal alcohol syndrome still remains unclear. As revealed by whole mount RNA in situ hybridization, it was shown that expression of a number of craniofacial cartilage-related genes, including shh, sox9a, sox9b, col2a1 and hand2, were all inhibited in zebrafish embryo by alcohol exposure. It suggests that alcohol exposure may result in reducing neural crest cell production, interfering neural crest migration, preventing chondrogenesis and eventually cause craniofacial defects. In addition, the transcriptional profile of pituitary hormones were investigated by RNA in situ hybridization. It appears that only growth hormone, but not prolactin and thyroid stimulating hormone, was inhibited by alcohol exposure. The reduction of growth hormone transcription was also confirmed by real time PCR. It also appears that the expression of upstream transcription factor pit1 and downstream target gene igf1 remains unchanged. It suggests that the reduction of gh transcription is mediated by a PIT1-independent pathway. The transcriptional profile of alcohol-exposed embryo was investigated by gene microarray analysis. It appears that the expression profiles of a number of development, cellular signaling, cell growth and apoptosis related genes have be affected by 1.5% alcohol treatment. It was noted that a number of retinal-specific genes were all repressed significantly. It consists with histochemical observation that alcohol exposure results in loss lamination and disturbed differentiation. This study help us understanding the molecular mechanism of fetal alcohol syndrome.

大自然的飛行家--蝴蝶飛行之初部探討

本研究主要針對蝴蝶之飛行進行探討,研究中主要探討蝴蝶翅膀形狀、身體重量、翅膀面積、展弦比、拍翅頻率及環境溫度對飛行速率之影響,並利用自製之風洞裝置,觀察蝴蝶之翼翅運動,分析通過蝴蝶模型之氣流方向及相關氣動力。研究結果顯示:紋白蝶展翅約4.5~5 cm,平均展弦比(AR)為1.71 ± 0.12,身體重量約為0.06± 0.02 g,翅膀面積約0.0012 ± 0.0003 m2,當紋白蝶身體重量愈重,則翅膀面積愈大(R2=0.9586)。另外,紋白蝶身體重量愈重、展弦比愈小,則飛行速率亦愈快(R2=0.5559、R2=0.4726)。23℃時,紋白蝶飛行速率為1.01±0.24 m/s,當環境溫度愈高(5、16、23℃),則飛行速率亦愈快(y=0.07x+0.7733,R2=0.6967)。風洞實驗發現:蝴蝶會逆風而飛,當風洞的風愈強,蝴蝶翅膀拍動角度愈大,且快而持久,仰角也變大(45 度);蝴蝶翼尖軌跡呈八字形,翼翅運動包含線性平移及旋轉;蝴蝶拍翅時,可在翅上方及前方產生低壓帶,在後方產生高壓帶,以利蝴蝶向前方飛行。另外,翅緣彎曲角度(上反角)愈大,蝴蝶模型之上升高度亦愈高,當上反角60°時,蝴蝶模型之上升高度最高(2.2±0.1cm)。This research approaches the flying ability of butterflies. Our research mainly discusses the weight, aspect –ratio of butterflies, frequency of flapping, and the shape, surface area of butterflies’ wings, and the connection between temperature and flying velocity. More over, we use the wind tunnel which was made by us to observe the movement of butterflies’ wings and analyzed the direction of airflow and aero-elastic which pass through the wind tunnel. Our research shows that Pieris canidia’s length of wings is about 4.5 to 5 cm. The average of aspect –ratio (AR) is 1.71±0.12 . Its weight is about 0.06±0.02 . And its surface area is about 0.0012±0.0003 m 2 . The heavier Pieris canidia is, the bigger its surface area will be (R2 =0.9586). In addition, the heavier it is, the smaller its aspect –ratio will be (R2 =0.5559, R2 =0.4726), and the swifter its flying velocity will be. When it is 23°C, the flying velocity of Pieris canidia is 1.01±0.24m/s. The hotter temperature is (5,16,23°C), the swifter it flies (y=0.07x+0.7733,R=0.6967). Accroding to the detect of the wind tunnel’s experiment , the butterflies will fly on luff. When the stronger the wind of the wind tunnel is, the larger the angles of wing’s flap are. And they are fast and lasting, the elevation also becomes larger (45°). The butterflies’ trochoids of wings mimic the word “eight”, and the movement of wingspan includes parallel movement of linearity and wheel. When butterflies flap, it will amount depression upon and in front of the wings, amounting the high pressure on the back so that butterflies can fly antrorsely. Furthermore, the larger the curvy angle of marginal wings (Dihedral) is, the higher the ascending height of model butterfly will be. When dihedral is 60°, the ascending height of model butterfly is the highest(2.2±0.1 ㎝).