全國中小學科展

2002年

周轉不靈(汽車過彎翻覆原理與對策)

「翻車」事件令人怵目驚心,輕則車毀,重則人亡。減少翻車事件,可減少悲劇的發生。而翻車絕大多數均發生在轉彎的路段,且伴隨著超速發生。因此,本研究乃針對汽車過彎行駛,探討其翻覆的原因以及改進之道 · 本研究乃利用實驗分析法以及理論驗證法進行研究,實驗中變化不同的汽車質量,車軸寬、車身高以及車軸寬/車身高,質量重心寬、高以及寬/高、傾斜度以及迴轉半徑等九種參數 · 於自製的紅外線偵測變頻式可調迴轉模擬機上以八部模型試驗車測試其翻覆轉速,並換算為翻覆速度後逐一分析討論之。經由實驗結果,本研究得到以下結論:一、汽車轉彎翻覆與離心力有關,當離心力大於臨界側向推力時,汽車即翻覆。臨界側向推力公式為 F = mg ( tanθ + K?) / ( l -K? tanθ ) 二、最大容許車速平方與轉彎半徑及質量中心寬高比相乘積成正比;而在定車速下,飲小客許轉彎半徑與質量中心寬高比成反比.前述各項皆與質量大小無關.三、提高轉彎路面傾斜度對防止汽車翻覆有確實的效果。而最佳的過彎防止翻覆方法是降低車行速度,提高轉彎半徑,增加路面外側傾斜度,以及提高汽車質量中心寬高比”四、汽車過彎不致翻覆的最大極限速度 Vc 以及最小轉彎半徑rc分別為 vc=〔 rg ( tan θ + K ?)/ ( l 一 K ? tanθ ) ]; rc =( V2 / g ) ( l 一 K?tanθ ) / ( tanθ + K? ) 五、本實驗所設計紅外線偵測變頻式可調迴轉模擬機,可有效的模擬汽車過彎翻覆,適用於中等學校物理、力學等學科的實驗課程。The accident of overturning a car always results in both destroying the car body and the death of the people. This project is to investigate what factors would have an effect on overturning a car and how to prevent a car from overturning.This project explores the factors by varying the mass of the cars, the distance between axes, the height of the car body, the ratio between the axis distance and the car height, the central gravity, and the declination. We test and record different overturning rotating speeds of eight model cars by a self-made adjustable simulator with a varying frequency infra-red detector. According to the experiment, the following results are obtained. I. The overturning occurrence is as a result of the eccentric force over the critical lateral force. The critical lateral force is F=mg(tanθ +K?)/(l—K?tan θ) 2. The square of allowable maximum speed is in proportion to the product of turning radius and ration of width to height for the center of mass; however, the allowable minimum turning radius is inversely proportional to the ration of width to height for the center of mass under constant vehicle speed. The above inference is independent of the mass of vehicle. 3. Increasing the declination can prevent a car from overturning. 4. The maximum speed for a car turning without overturning is Vc. The minimum turning radius is r. Both are expressed as follows:Vc=[rg(tanθ +K2)/(1—K?tanθ );rc=(’V2/g)( I —K?tanθ )/(tanθ +K?)5. The self-made adjustable simulator with a varying frequency infra-red detector can be used in the experiments of the middle school science curriculum.

強電場下DNA穿透細胞膜的蒙地卡羅電腦模擬

去年暑假,我們從Newton雜誌得知,布洛貝爾博士(Dr. Gunter Blobel)由於發現了蛋白質如何在細胞之間運送,增進了人們對遺傳性疾病的了解,因而榮獲1999年的諾貝爾醫學獎。同為高分子鏈的DNA,在基因遺傳工程中常被用來在強電場的情況下穿破細胞膜,以進行基因的改造,其穿的物理機制又為何?在一場演講中,我們知道鍵振盪模型(bond-fluctuation model)可用來模擬高分子系統,因此我們想以之模擬DNA在強電場下穿透細胞膜的行為。

氧化壓力影響基因轉換表現對脂肪分化之作用

細胞脂肪分化是造成肥胖、骨質疏鬆、和糖尿病的重要前置因素。我們若要維持良好身材又想省去減肥藥的問題,那麼我們必須了解造成脂肪化的原因,才可能擁有好的預防之道。利用人類骨髓間質細胞可以分化成骨質與脂肪等細胞的特性,我們研究氧化壓力對間質細胞\r Ras基因轉換表現後骨質與脂肪分化的影響。結果發現以添加超氧根 (O2-,l5nM)形成氧化壓力,可促進正常Ras基因表現的間質細胞朝骨質分化;相反地,超氧根會促進\r Ras基因突變而不表現的細胞,朝向脂肪分化的現象。進一步研究其作可原理,發現氧化壓力可促進 RaS蛋白質啟動細胞外訊息活化酵素(ERK),接著驅動骨質轉錄因子(CBFA1)表現,再到骨鈣蛋白質與骨結節形成。而抗氧化酵素(超氧根轉化酵素;SOD,5OOU/ml)的作用,可以抑制正常Ras基因細胞氧化壓力下骨質分化的進行;但不能防止氧化壓力促進Ras基因突變細胞,朝向脂肪分化的作用。總結而言:Ras基因的表現與否,是決定脂肪分化的關鍵切換點;也是影響氧化壓力對間質細胞朝骨質分化的樞紐。這種基因與氧化壓力互動影響骨質與脂肪分化的剖析,將有助於提醒人們:使用抗氧化劑來調節抗衰老、肥胖、和美容時,必須是在不同情況和不同基因體質的人,有所不同。 \r Human\r mesenchymal stem cells are able to differentiate into bone, muscle, cartilage or\r fat tissues. Our preliminary study with human mesenchymal cell line (HS-5) showed\r that HS-5 cells could differentiate to bone, cartilage and muscle but not fat cells\r as determined by histochemical staining of phenotypes. We have further studied the\r influence of oxidative stress on the switch between bone and fat cell differentiation.\r Results showed that oxidative stress started with exogenous superoxide, produced\r by the interaction of xanthine oxidase and hypoxanthine, promoted the differentiation\r of osteogenic lineage showing expression of osteocalcin and bone nodule formations.\r The mechanism was investigated and superoxide was found to induce ERK (extracellular\r regulated signal kinase) activation; and then the expression of osteogenic specific\r transcriptional factor (CBFA1). A plasmid containing ras-mutant (Ser 17 Asn) which\r can inactivate the expression of ERK was transfected into the HS-5 cells for studying\r the influence of oxidative stress on ras-mutated mesenchymal cells. Surprisingly,\r it was found that oxidative stress did not promote osteogenesis but it enhanced\r adipogenesis from the ras-mutated HS-5 cells. Further studies indicated that superoxide\r neither induced ERK activation nor CBFA1 expression, but it did enhance expression\r of adipogenic specific transcriptional factor (C/EBPα) and lipoprotein lipase in\r the ras-mutated mesenchvmal cells. Taken together, the study model to induce the\r bone cell differentiation from human mesenchymal stem cells may be employed to make\r bone cells for tissue engineering.

魚洗水跳現象的探討

In the previous year study, we assumed that the fish basin as a column-shape model in order to exam and explain how the water spouting. This year, we established a reality-like situation of the fish basin to construct our theory base. At this point, round-waves and up-down waves are found as the beginning point of the water spouting. The sound from the basin is the frequency of the vibrations. Meanwhile, this process enables us to understand the causes of four, six, and eight waves. In addition, we tried to change the basin's positions, the capacities of water, the densities of liquids, and the sizes of the containers to demonstrate the theory. Furthermore, we used similar containers, such as high-heel cup and big magnetic bowl to experiment. The results are also corresponded with the theory. These results can also be used to explain the Chinese aeolian bell, clock, shaking bell, etc. That is a major innovation for us. Finally, we obtain better understanding of the abstractive theory though the simulation of the computerized photographs. 魚洗,也稱龍洗,傳說是中國唐宋時代皇帝洗臉的臉盆,內底四條魚紋,麟尾畢具。洗內盛水後,用手摩擦其兩個雙耳,立即發出響亮的嗡鳴聲,並出現美麗了漣漪,水珠四濺,摩擦越快,聲音越響,波浪翻騰,水珠越烈。對此在上一年度的研究中,是將洗盆視為圓柱狀,然後由圓柱狀所建立的模型去解釋水跳的原因,初步瞭解了水跳的原因。今年我們以洗盆真實的情況建立理論模型,在殼體產生共振的圓形駐波及上下駐波,此為水跳產生點,此時殼體發出的聲音就是共振的頻率。也瞭解了有四個、六個、八個、十個波腹的原因。並以改變殼體不同位置、水量、液體密度及洗盆大小等變因應證模型,結果與理論相符合。繼而以高腳杯、大磁碗等類似魚洗盆構造的容器,加以實驗應證,也能符合此理論。甚可推到中國古時候的編鐘、搖鈴、風鈴等器材。對於我們總認為碰撞就產生聲音的觀念實是一大突破。最後經由電腦動畫的模擬,讓此抽象的理論更容易瞭解。

空間震盪與擴散

筆者將K?Cr?O?置於明膠溶液中煮沸,加入AgNO?水溶液,使之造成空間震盪反應。產生Liesegang ring。並且在研究空間震盪的過程中,筆者在研究過程中同時發展出一個程式,可以完成空間震盪實驗完成之後,由其震盪條紋的時空關係,得知ksp與擴散係數。或者可以在已知ksp和擴散係數的條件之下,預測出空間震盪實驗完成時的情形。We put K?Cr?O? into glutin, boiling it. After it concretizes, add AgNO? aqua into the glutin of K?Cr?O?. It is made to be space oscillation reaction with the Liesegang rings. And when we research for the process of space oscillation, we develop a program which can know the Ksp or diffusing coefficient after finising an experiment in Lablratory. Or we can predict the statement after the experiment on the condition of the Ksp and diffusing coefficient.

以3DVR虛擬實境融入教學活動設計之研究

面對一個終身學習,多元化學習的社會,學習的方法不再侷限於閱讀或求教於師了,取而代之的是電腦科技的變革。上屆學長利用線上代理人融入遠距教學的作品令我印象深刻,但總覺得少了些趣味及互動性,於是本實驗嚐試將虛擬實境加入線上代理人及遠距教學,利用空間魔法師建構出來的環境,讓使可者能夠融入其中,悠遊在虛擬的世界,並配合鍵盤的滑鼠的控制移動,點選建構出來的虛擬物件,透過超連結連結至網路上的知識網頁,配合線上代理人的互動及帶領,結合了主動、趣味、互動與便利,開創未來的學習方法,一個講求效率、速度及克服空間無時無刻都能學習的環境。With the arriving of 21st century,things are widely different,including the ways of learning. Because of the revolution of multi-media,computer technology will change the traditional way of learning. I was impressed by the master piece 「Long-distance with Agent」 which was done by the schoolmates last semester. But I feel their work still have much room for improvement,so I combine to use the virtual environment with the advantages of their work. Learners can move and click the objects in the virtual reality space,and they can be linked to the knowledge website through the Internet. Learners can enjoy the interesting ,fast,interactive and efficient learning environment. This work is done by the Space Magician Ver3.0, which is used to design a 3D virtual reality environment. And the users can enjoy the net-surfing and through the hyperlinks to get the information.

聚球藻 RF 一 1 品系生物時鐘之特性

我們成功的用溶氣計偵測到了聚球藻 RF-1 在 28℃下光合作用的概日韻律。和傳統的研究方法比起來,這個方法具有連續偵測的優點,減少因不斷取樣所造成的影響,此實驗可觀察到聚球藻 RF-1 溶氣量之變化圖與一般藻類(如單殼縫藻)不同.在光 /暗條件下 RF-1 之溶氣量的增加與減少均呈週期性變化,而且此變化現象在進入連續照光後仍然可以維持兩個循環以上,這些結果顯示以溶氣計連續偵測聚球藻 RF -1之概日韻律是可行的,而且所得到的變化圖形遠比傳統方法(於不同時間取樣)所得者自然。本實驗同時發現含聚球藻之培養液的溫度,在進入黑暗週期時會有明顯的上升,由於其變化程度比其他藻類明顯,如加以探討應有助於對此藻以及其韻律特性之瞭解。We successfully detected the photosynthesis circadian rhythm of the prokaryote Synechococcus RF-1 under 28℃ by a DO (Dissolved-Oxygen) meter. The advantage of this method, comparing with the traditional methods, is that it can detect signals continuously, reduce the influence of discrete sampling. The DO curves of the Synechococcus RF-1 are different from that of other algae. Under Light/Dark conditions, the DO values of RF-i increased and decreased periodically. The periodic phenomena progressed over two cycles under constant lighting conditions. These results revealed the feasibility of using DO meter to continuous detect the circadian rhythm of the Synechococcus RF-1 The detected DO curves looked more natural than those obtained in the traditional discrete-sampling method. We also found that the temperature of the culture increased in dark cycle. Since the variation is clearer than that of other algae, further investigation will benefit the understanding of the Synechcoccus RF-i and its circadian rhythm.

Amazing Fairy Chess -討論多元方形鏈的數量

在這篇研究報告中,我們討論的是一種方形集合圖形的數量。”多元方形鏈”約略在 60 年代被提出,衍生出一系列的問題和遊戲,例如熟知的電玩軟體 『 俄羅斯方塊 』 ,或是 『 益智積木 』 的遊戲,都是多元方形鏈的應用。在這些問題當中,最令人頭痛的難題就是 n 元方形鏈的圖形總數。為了解決這道難題,我們採用一種轉換方法將圖形轉換成序組,並且給出序組的性質,再據此寫成 C 語言的程式;反覆地修改程式以增進執行效率及速度,最後利用該程式成功地統計出圖形總數。 In this report, we discussed the amount of polyominoes, the graphs of a set of squares. “Polyominoes” has been brought up in 1960s, and later developed into a series of questions and games, such as a well-known video game — Tetrix, and the game of puzzle blocks. Both are the applications of polyominoes. Among those questions, the toughest one is the amount of n-polyominoes. To solve this problem, we used a method which transforms the graphs into sequences. By looking into the properties of those sequences, we obtain a set of rules that can be used to determine the quantity of n-polyomines. The rules are implemented into computer codes in C language with proper modifications made to speed up the efficiency of our algorithm. The computational results show that the amount has been successfully calculated.

台灣和東亞地區的氣候變遷

由人類活動造成的溫室效應可能導致地球溫度升高,聖嬰現象加劇等現象與災害,本文利用個氣候中心發展出的模式,推估台灣和東亞地區未來氣候變遷的情況,我們發現當大氣中的二氧化碳濃度增加為現在的1.9倍時,台灣地區的年平均溫度將升高0.85-2.50度C而東亞地區將會升高1.46-4.07度C,在同條件下個模式的平均推估量也顯示,台灣地區將每天增加0.10公厘的降水,而東亞地區每天將增加0.08公哩,我們希望這個研究結果可以做為其他相關研究的基礎,使大家提早因應未來氣候變遷所可能引發的種種變化;Greenhouse effect, incurred mainly by human activities may result in lots of phenomenon and damages such as the increasing of the world's average temperature and he aggravation f the "ElNino" effect. In this research, we simulate future metrological values by employing several simulation modes developed by different climate centers and predict future climate changes in Taiwan and East Asia area. We found that when the concentration of carbon dioxide exceeds 1.9 times than current value, the estimated range of the increased year-average temperature are0.85-2.5℃ and 1.46-4.07℃ for Taiwan and East Asia, respectively. Under the same condition, the ensemble mean reveals that the precipitation raises will be 0.1 and 0.08mm per day, for Taiwan and East Asia respectively. We hope our work can be the foundation of other related researches, and all the researches together can help for coping with possible damages caused by future climate changes.

抽籤機

此篇報告中,主要是在敘述以單晶片8051為主體,運用其所具有之功能,製作成此作品,稱為記數抽籤機,又稱抽籤機,根據本篇報告結果,可歸納出以下結果:1.本實驗能讓初學者對單晶片8051之特性與功能有更深的了解,以增進實驗與成品實作的能力。2.此作品以便利為原則,故其體積不大,重量輕攜帶方便。3.使用之元件普遍,價格便宜,在電子材料行均可買的到,成本低。4.依本品之功能,可用於學校讓老師進行抽問,也可用於其他有抽籤或抽獎活動之場合,公平又公正。;In the report, we take the single chip 8051 as a main body, making use of function to do the counting drawing lots machine, which are also called drawing lots machine. According to the resultof this report, conclusions are as followings: 1. With the experiment, the beginners egt deeper understanding about the characteristics and the finished products. 2. This machine is light and its volume is small, so it is easy and convenient to carry with. 3. The essential elements are common,cheap and can easily be bought in the store which is sellong electronic materials. 4. The drawing lots machine can be used at schools when teachers want to pick out some students to ask or it can be used for some drawing lots occasion as well. The outcome is just and fair.