全國中小學科展

地球與環境科學

在浪碎之前

本研究以模擬實驗探討波浪在斜坡海灘上的行為。實驗在長1.8公尺、寬0.75公尺的透明水波槽中進行,以長0.90公尺、寬0.60公尺的木板在深水區產生單峰波向淺水區前進,同時以數位錄影機錄影後進行分析。結果發現單峰波由深水進入淺水,波速會變慢,但當波高對水深的比值增加到一定值時,波速隨水深變淺而變快,波高也變高。當比值繼續增加,波前方的水面形成垂直的水牆,接著波就碎了。如果坡度較緩,碎波點會離水岸線較遠,水牆維持的時間也較長。有趣的是,水波槽中的單峰波移動時,有蠕動現象,波寬會伸縮,波高會起伏,波速也會些微地忽快忽慢。 ;This study simulates the behavior of the wave on a sloping beach. Experiments are performed in a sloping wave tank. A paddle wave maker at the deeper end generates single crest waves. To analyze the wave height, speed and breaking point, a digital camera is used. The results show that when the wave moves toward the coast, the shallower the water is, the slower the wave moves. But when the ratio (wave-height/water-depth) exceeds a critical value, it turns out that when the water is shallower, the wave speed becomes faster and the wave height, higher. As the ratio keeps on increasing, the front part of wave becomes a vertical water-wall, and then breaks. If the slope is gentler, the breaking point will be farther from the coast and the water-wall will keep for a longer time. An interesting phenomenon is also found that a single crest wave squirms with slightly undulated changing of width, height, and speed while it propagates in the sloping wave tank.

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.

太陽短期活動對地球磁場與大氣溫度異常的影響

This study analyzed how short-term solar activities interact with the earth atmosphere, by using two statistic methods: Diffusion Entropy Analysis (DEA), and Standard Deviation Analysis (SDA). Since solar activities influence the Earth atmosphere in its radiating heat and magnetic field, we use DEA and SDA to calculate the exponents, H and δ, of the scaling law in three time series: “the intensity of solar flare” (representing by SOLAR H-alpha flare index), “magnetic anomaly of magnetosphere” and “sea surface temperature anomaly”. The values of H and δ show the time memory and correlative relationship between the event and next event happening in time series. When H = δ = 0.5, events occur in random. When 0.5

由嘉義地區的氣象資料來探討二十四節氣與聖嬰現象

二十四節氣是中國古代對氣象觀測的智慧結晶,由於近幾年來聖\r 嬰與反聖嬰現象的影響,在透過嘉義氣象觀測站的協助之下,利用\r Excel 進行簡易的雨量和氣溫統計,並配合中央氣象局發布的環流型\r 態和農業災害,來探討二十四節氣在嘉義地區的適用性。\r 以陽曆來區分節氣,每年會誤差6 小時,加上四年一閏,剛好彌\r 補差距,農曆則需19 年。至於聖嬰現象對嘉義地區則呈現涼夏和暖\r 冬,但在反聖嬰現象中則變為加強四季之特性,即是熱夏與寒冬。兩\r 者都造成雨量集中夏秋兩季,形成冬春乾旱。至於二十四節氣則是以\r 夏、秋的氣溫和雨量相關的諺語較適合嘉義地區。\r Abstract\r The 24 Solar Terms, is the achievement of weather observation from\r ancient China. Because of the effects from El Nina and La Nina these\r years, we proceed simple statistics of rainfall and temperature by using\r Excel and the assistance from Chia-yi Weather Station. We adopt the\r Circulation Type and the damage of agriculture from Central Weather\r Bureau, to discuss if the 24 Solar Terms for in Chia-yi area.\r To divide the 24 Solar Terms according to the solar calendar, there’ll\r be a six –hour gap every year. The gap could be made up every four years.\r But with the lunar calendar, it takes nineteen years to offset. The El Nina\r shows cool summer and warm winter in Chia-yi area, but the La Nina\r emphasizes the characteristics of the four seasons. It shows hot summer\r and cold winter. Both of them rain mostly in summer and fall, and cause\r the drought in winter and spring. The saying of the 24 Solar Terms is\r suitable for the temperature and the rainfall during summer and fall in\r Chia-yi area.

間歇泉的研究

間歇泉是一種十分奇特的地質景觀,地下水受到火成岩入侵所帶來的穩定熱源加熱,產生水蒸氣,利用水蒸氣形成的空氣柱壓力推動水由地底噴發出地表,也因為熱源穩定使得噴發時間差接近一定值,形成所謂的「週期性」。而根據實驗結果發現,管壁較薄的管子,在噴發之後,會使管中殘餘的水稍作降溫,加上補充的冷水使系統降溫;管長愈長時,蓄水槽中的水量較多,提高溫度所需的時間也較長,而延長了噴發的週期,最後歸納出間歇泉形成及存在的三個主要條件:(1)穩定的熱源;(2)細長的孔道;(3)豐沛的地下水。 The geyser is a very amazing sort of geologic scenery. Its principle is that the heat source of invasive volcanic rock heats the underground water to produce steam that results an air-columnar with a large pressure to erupt through the underground on the surface. Because of the steady supply of heat source, the period between eruptions is closed to a constant called “periodicity.” According to the result of the experiments, the tube that have thin wall can lower the remaining water’s temperature a little and the cold water’s supply can also lower the plumbing system’s temperature after eruption. Besides, the water in the longer tube needs more time to higher its temperature to protract the period because it have more water in its reservoir. Eventually, there are 3 essential conditions of the geysers’ existence concluded: (1) steady supply of heat; (2) a thin and long standpipe; (3) abundant underground water.

假如我是正常的?!—再探渦流脫離是否可能為聖嬰發生動力

聖嬰現象為全球的共同話題之一,由於其發生會影響全球性氣候的改變,使原本乾旱處下起傾盆大雨,原本潮濕氣候的地區成了乾旱地區,導致生命、財產嚴重性損失,這也是引發本研究想站在不同科學領域角度來探就聖嬰現象的發生的原因。目前科學家大都以大氣觀點來說明聖嬰的成因:太平洋上因風向改變引起海水流向或動能變化,導致太平洋赤道地區及南美洲西側海面溫度的改變,而觸發聖嬰的發生。由於海水的熱容量比空氣大,因此我們想以海洋觀點來說明另一種可能觸動聖嬰發生的動力,在生活經驗裡,我們發現水流通過障礙物會在後方形成渦流,因此,當南極繞極環流通過德瑞克通道受到南美洲南端阻礙時,有可能在南美洲形成週期性渦流生成及脫離的現象。「這樣的渦流是否存在?」、「渦流脫離後在南美洲左右岸海面溫度、高度是否發生變化?」、「此動力是否進而觸發聖嬰現象?」,是本研究期待以新思惟解釋引發這個全球現象的另一可能動力。

翻開東北角那一頁---和美一帶漸新統貝類化石排列方式和古水流關係之探討

This study tries to reveal how the velocity of flow influents the orientations and scattering patterns of the two-valve shells (we use Pecten in this study) during depositing processes by comparing the laboratory studies with the field observations. We learn from the laboratory experiments that the shells deposit at random directions when they are too crowded and are oriented to a certain direction when they are more scattered. We also find out that the shell fossils whose dorsal sides towards downstream with upward concaves are most likely to move. On the contrary, the shells whose dorsal sides towards upstream with downward concave are the most reluctant to move Examinations of the outcrop of the bedding of Pecten fossils, which are located near Long Dong, the northeastern tip of Taiwan, show that a lot of the shells settled along a certain direction and most of their concaves are upward. However, some of the shells with obvious orientation have downward concaves, which implies the depositional environments were under high current velocity. And the numbers of the shells whose dorsal sides are oriented to Northern East are about equal to those whose dorsal sides are oriented to Southern West. This result coincides with the results of the laboratory study. However, the experimental results can apply to the field analysis under certain assumptions.本研究就影響貝殼排列的水速作試驗,尋找水流和貝殼排列的關係,並和地層中實際的貝類化石做比較,藉以回推古老沉積環境。結果發現大量貝殼集中的情況下,貝殼間彼此的影響力會大於單純的水流沖擊;當貝殼較分散時,可以看出貝殼的頭部皆會一致朝向水流的來向作排列。而最適合移動的型態是凹口向上且頭部不朝水流來向的貝殼,而最穩定的型態是頭部朝水流來向的凹口向下貝殼。觀察實際地層,貝類化石大致上也有方向性的排列且正反面貝殼都有,可以推得當時沉積的水流大,故有足夠的動能讓貝殼重新排列。但由於試驗環境定和自然環境有所差異,仍有限制存在。

Effect of Salt Concentration on Evaporation of Sea Water

Every year more soluble and insoluble substances are added to the oceans by runoff. This process slowly increases the salinity of the oceans. As the salinity of the oceans increase, what effect will this have on our climate? The purpose of this investigation is to determine how an increase in salt concentration affects the evaporation of sea water. Four ten liter aquaria were filled with six liters of distilled water in each aquarium. One aquarium contained only water. The other three aquaria had different amounts of Kosher salt added as follows: 120. grams, 240.grams and 480.grams. Measurements of the level of water in each tank were taken over a period of two months. The tank with the highest concentration of salt had the smallest rate of evaporation. In the feature with less evaporation of sea water the atmosphere will receive less moisture. This could result in fewer clouds and less rain fall for the planet.

蟹狀星雲的擴張

By comparing eight different epoch images of the crab nebula taken through 1942 to 2004, we have calculated the expansion velocity of 27 optical bubble features and 60 filaments. The mean expansion velocity of bubble features and filaments is 0.173 arcsec/yr and 0.15 arcsec/yr, respectively. We also estimated the maximum radial velocity of the expansion by analyzing the emission spectrum of the nebula. The maximum radial velocity is 1385.5 km/s. Combining these measurements indicates that the crab nebular is approximately 5870 light year away. In addition, if we assume that the nebula has been expanding at a constant rate, our expansion velocity projected backward indicates the mean date of the supernova event as A.D 1124, more than 70 yrs later than the accepted date of 1054. The result confirms the well-known acceleration in the crab's expansion. Although we have analyzed eight images with a 62 yr baseline, the acceleration still can't be derived from this study. 透過量測由1942年到2004年之間八張不同年代的蟹狀星雲中爆炸後殘骸的位置變化,可以計算出蟹狀星雲爆發的擴張速度。本研究選定了27個包狀物和60個纖狀物,計算出的擴張速度分別為0.173 arcsec/yr.和0.150 arcsec/yr。再透過分析蟹狀星雲的光譜所計算出的徑向速度(radial velocity)為1385.5 km/yr,進而推得蟹狀星雲的距離分別為5430光年和6370光年,平均值為5870光年。 另外,如果假設擴張速度是等速運動,那麼把求得的擴張速度倒推出的爆發日期是在西元1124年,這比中國紀錄中超新星爆發的1054年晚了70年。這顯示出蟹狀星雲的確非等速擴張而是有加速度的狀態,才會造成以等速倒推發生日期時,晚了70年。雖然本研究中分析了相差62年之久的八張影像,仍然無法分析出星雲的擴張的加速度情形。

太陽系外行星光度研究

搜尋太陽系外行星(extra-solar planet;exoplanet)是當今天文學家最重要的計畫之ㄧ;其中,當系外行星經過其主恆星碟面時,會造成光度略微下降,稱之為凌日現象(transit) 。本研究便是利用鹿林天文台SLT(Sne Little Telescope)望遠鏡來拍攝兩顆已知的系外行星HD 189733 b 和HD 209458 b在凌日時的影像。 我們得到約4000 張影像,再經過影像修正與資料分析後,我們作出凌日光變曲線圖、Bin圖及相位圖,並從中探討其特性。 經分析判斷後,HD 189733 看到一個剛開始發生和一個完整的凌日現象,分別由B濾鏡和 R 濾鏡所拍攝;而 HD 209458 則看到兩個剛開始發生,三個要結束的凌日現象,分別由B濾鏡、R 濾鏡和 Hα 濾鏡。 並由光變曲線,推得HD 189733 的基本參數,包括:行星半徑為 1.242個木星半徑、軌道傾角為88.94 度以及軌道半徑為 0.03115 天文單位。 Since 1995, more than 200 extra-solar planets have been found. Until today, astronomers still make efforts in searching extra-solar planets because it’s one of the most important projects in this century. During the crossing by the stellar disks (i.e., transits), the exoplanets will cause the brightness to decrease by a small amount. In the project, we have focused on the observations of two known transit exoplanets, HD 189733 b and HD 209458 b. The photometric observations were performed with the 40-cm SLT telescope on the Lulin Observatory. The results from the image procuring, data reduction and analysis are presented. We accrue and plot the light curve, bin and phase. We found out that HD 189733 has two transit ingresses with B, R band, and HD 209458 has two transit ingresses, two transit egresses with B, R, Hα band on phase. We figure out planetary parameters, RP is 1.242 RJ, inclination is 88.94° and orbital semi-major axis is 0.03115 AU by transit light curve.