液滴在我眼前蒸發
本研究的目的在觀察液滴的蒸發過程,探討影響一滴蒸發方式改變的變因。我們利用數位攝影機外加近攝鏡頭,由側面逆光拍攝液滴蒸發過程,並轉錄成電子檔利用電腦協助分析。液滴影像分隔放大投影在方格紙上,以便測量接觸角及高度的變化。結果發現蒸發情形可分為三種:Ⅰ.當接觸角大於九十度時,液滴和界面的接觸線迅速外擴,直到接觸角遞減至90度後定住不動,蒸發終了時,接觸線迅速內縮,留下縮小的實心殘跡。Ⅱ. 當接觸角小於九十度時,接觸線先些微外擴迅速外擴,之後定住不動,直到蒸發終點,液體內縮,留下環狀殘跡。Ⅲ.當接觸角小等於九十度時,接觸線始終定住不變,液滴蒸發後留下原大小的實心班跡。液滴蒸發時接觸角和高度並不是連續變化,而是交互階梯式遞減。本研究的結果可應用在探討噴漆及噴墨印表機的噴墨印刷上。The objective of this investigation is to observe the evaporation of liquid drop and find out the factors that could affect it. A digital camera with micro lens is used to film the process of the evaporation. And a close-up of the sample drop is taken with backlight. The results are analyzed with a personal computer. The magnified images of the drops are projected on grid papers for measuring the changes on contact angles, and heights of drops. We classify the evaporation of a drop into three types: Ⅰ. The contact angle is greater than 90 degrees. At first, the contact line will spread outwardly till the contact angle decrease to the 90 degrees and then be pinned until the evaporation reach its terminal. At last the contact line quickly contract inwardly, and a solid stain remain. Ⅱ. The contact angle is less than 90 degrees. The contact line will spread slightly and then be pinned. At the terminal the liquid contract inward, and a ring-like stain is formed. Ⅲ. The contact angle is equal to 90 degrees. The contact line will always be pinned, and no ring, but spot stain is left. During the evaporation, we discover that the contact angle and the height of the drop do not change continuously but alternatively decrease by steps. The results of our investigation can be applied to the aspects of paint-spraying and jet printers.
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.
免疫治療的新展望:從一個疾病的動物模式,探討樹突狀細胞的培養與分析
胰島素依賴型糖尿病(insulin-dependent diabetes mellitus; IDDM)是一種胰島素無法正常分泌的自體免疫疾病;而NOD老鼠(non-obese diabetic mouse,NOD)的病徵與其非常相似。藉由觀察NOD老鼠發病前後外顯行為及疑導組織切片的差異,我們認為胰島素依賴型糖尿病的致病機轉是因為T細胞工及胰島組織中製造胰島素的β細胞,使胰島素分泌不足而引起糖尿病;而樹突狀細胞(dendritic cell,DC)是調控淋巴細胞反映的重要調節細胞,未來可望利用樹突狀細胞進行胰島素依賴型糖尿病的免疫調控治療。本實驗即是利用IL-4、GM-CSF使NOD老鼠的骨隨幹細胞分化樹突狀細胞,並藉由控制NOD老鼠的年紀與的數突狀細胞培養天數,希望取得較多的數突狀細胞,以利未來免疫治療之用。Insulin-dependent diabetes mellitus (IDDM) is a spontaneously occurring autoimmune disease in which cellular immune components mediate destruction of the insulin-producing βcells of the pancreas. It begins with an asymptomatic stage during theβcells are gradually destroyed. These patients have to depend on injecting insulin to lower their blood glucose, facing the dander of being infected. So we want to research into the cause of IDDM by model animal- NOD mouse (non-obese diabetic mouse). We observe the differences of exterior behavior and sections of pancreas organization between NOD mice and normal ones. It has been shown that the immunophological mechanism of IDDM is T cells destroy βcells of genetically predisposed individuals and result in insufficiency of insulin-producing. Dendritic cells(DC), having great Ag-presenting ability, are related to IDDM. We cultivate bone marrow stem cells of 5-week-old,8-week-old, and 21-week-old NOD mice treated with IL-4,GM-CSF and make them differentiate into dendritic cells. The result shows that using 8-week-old NOD mice to cultivate will get the largest amount of dendritic cells. We also compare the percentage of differentiated DCs for 6 days’ culture with 9 days’,and we find that 9 days’is better. Dendritic cells are the effect Antigen-presenting cells which can be used for immunotherapy of IDDM , though , its complicated mechanism still needs further researching and developing. We hope in the future IDDM patients could get rid of the suffering of injecting insulin in their whole life.
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。
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!
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.
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.