國王的海市蜃樓
在夏日的午後,在炎熱的柏油路面上很容易可觀察到遠方的 路面上,出現如鏡子般的倒影,看起來彷彿前方有一灘水,但當 我們向前進一些時,倒影卻突然消失了,這個現象,一般稱為海 市蜃樓。 一般解釋海市蜃樓的成因,都是由於在上層的低溫空氣,和 在下層靠近路面的高溫空氣,因密度的不同,以致於折射率的漸 層差異,繼而產生全反射。 但我們觀察發現,地面與上層空氣的溫差,並非柏油路面上 假積水現象及倒影出現的必要條件;反而和入射光的角度、路面 的平坦程度及路面的性質有關。我們提出了粗糙面在入射光的入 射角接近90度時,可發生單向反射的模型。並由實驗來驗證假積 水現象及倒影主要的成因是「柏油路面的單向反射」而非「空氣 的折射與全反射」。 Under the scorching sunshine, we can see the reflection on the tarmac in the distance just like a water puddle on the road. And the water also reflects the people and object nearby. But, in fact, the tarmac road over there is very hot and dry. Therefore we call the phenomenon as the “false water puddle on the tarmac.” According to the textbook , the main reason for “false water puddle on the tarmac” is that the temperature difference leads to the refraction of the light and causes the phenomenon. However, from our observation, the theory still can’t explain some phenomenon, For example, the “false water puddle on the tarmac” remains to appear when the wind blows fiercely. Even with little temperature different at night the phenomenon is still obvious. Therefore, in our opinion, the temperature different of the air is not a necessary condition of “ the false water puddle on the tarmac.” We bring up the model to explain the phenomenon that when the incident angle of the light approach 90 degrees, the light will result in one-way reflection. According to the model, furthermore, we make experiments at midnight and at dawn. The result of the experiment assures us the hypothesis of the model, Consequently, we hold the ideal that the main condition of the “false water puddle on the tarmac.” Is not because of the refraction and the total reflection but because the light reflects off the road and result in the one-way reflection on the tarmac road.
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!
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.
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.
臭氧事件日-氣象與地形對臭氧於近地大氣層之生成與傳輸影響
2001、2002 年監測資料被用以探討風場、時間、地形對臭氧傳輸影響。完成沿海地區與盆地內各二次採樣分析,探討各污染物與風場之垂直變化,及地面臭氧分布與風場變化。結果顯示各月份與全年之日間,其相對濕度與O3 相關度最高,日照次之。提高濕度,最能抑制[O3]。夜間NO 與O3 的相關度最高,濕度次之。臭氧事件日時:(1).11:00 即可產生高臭氧,(2).沿海地區在臭氧事件日仍保持低[O3], (3).盆地效應改變風場,使近山地區[O3]居高不下,(4).因處O3 不斷被吹入,沿海地區傍晚時之[O3]下降速度減緩。臭氧事件日之O3 生成速率R 與消失速率常數L 被求出,其中14:00 後之R 與L 值均由正值轉負值,顯示大氣反應型式明顯轉變。R 與L 值在14:00∼15:00 間最小,係因O3 反應生成光化學煙霧所致。16:00 後另一低R 與L 值,則可能導因O3 與微粒或水份反應。分析結果顯示:(1).污染物會隨高程而略增,最高濃度在300∼500 m 處,(2).各高程大氣均可分析出73 種主要HC,其隨高度之分布被繪出與探討,(3).低層大氣會有較多低分子量HC,而高層大氣則有較多高分子量HC。結果亦顯示: (1).盆地內[O3]、[NO]與[NO2]不僅較沿海地區高,且於各高程之變動亦較大,(2).沿海地區THC、烷、烯類均較高,且隨高程增加而增高,但在盆地內則相反,(3).二地區各高程之鹵化物、芳香族、氧化物與其他有機物之平均濃度相近,但沿海地區之濃度變動較大。探討O3 之二傳輸現象獲知:(1).風吹向盆地內時,[O3]隨風向遞增,R 與L 會由12:00 之正值,轉為14:00 之負值;(2).風由盆地內外吹時,[O3] 隨風向遞減,R 與L 值提前於12:00 即為–202.561 與–1.621,但14:00 時R 與L 值增大為–76.411 與0.244, (3).風向並非決定[O3]的主要因素,地形與環境因素才是。實驗結果證實:(1).不同HC 會影響O3 之生成與消失,(2).改變[NO]o 對[O3]影響不大,但高[NO]會使得[O3]下降略緩,(3).降低HC 與[NOx]雖可使 [O3]略降,但提高濕度最能抑制[O3],(4).在O3 的衰減量上,[O3]隨濕度增加而快速降低,但衰減率則隨[O3]o 的增加而降低。一個臭氧之統計模式被建立,臭氧與水反應速率常數與速率式也被求出。
The monitoring data were used to investigate the effect of surface wind, time, and terrain on the transformation of ozone. The sampling and the analysis in the coastal and in Taichung basin were completed. The vertical distribution of O3, NOX and HC and the different altitude wind were investigated. The contour of O3 and surface wind with 3D map were plotted. The results show that the correlation behaves relativity of relative humidity with ozone is the best, and solar radiation is the next. Enhancing environmental moisture can efficiently decrease ozone concentration. In each ozone event day are: (1) the high [O3] always starts from 11:00, (2) the ozone concentration on the coastal is always low due to the high humidity, (3) the high [O3] in the east of the basin is due to the basin effect which causes changes the surface wind, and (4) in the evening, the descend rate of [O3] in the coastal area is lower because ozone blows into the coastal area. The formation rate (R) and disappear rate constant (L) of the ozone event day were obtained. The values of R and L change from plus to minus before 14:00. The values of R and L are lower at 14:00∼15:00 due to the photochemical smog formation. And another lower R and L value before 16:00 may be due to ozone react with particle or water. The results of analysis indicate that: (1) the concentration increases with increasing altitude, and the maximum is at 300∼500 m height, (2) 73 kinds of hydrocarbons were identified, and the concentration variation with altitude was also investigated, and (3) most of low molecular weight HC are at lower altitude, otherwise high molecular weight HC are at higher altitude. The results also show that: (1) [O3], [NO], and [NO2] on the basin are not only lower than on the coastal, but also their variability of concentration are big, (2) THC, paraffins, and olefins on the coastal are higher than on the basin, and the concentrations increase with increasing altitude on the coastal, but on the basin is decreasing, (3) the average concentrations of halides, aromatics, oxides, and others are similar on both area, but concentration variability on the coastal is obvious. Two types of O3 transformation was investigated, the phenomenon indicts that: (1) when wind blew into the basin, [O3] increased with wind direction. The value of R and L change from positive (12:00) to negative (14:00); (2) when wind blew out of the basin, [O3] decreased with wind direction. The more small value of R (−202.561) and L (−1.621) appeared at 12:00 earlier. But the value of R and L will become bigger to –76.411 and 0.244; (3) ozone concentration does not just dependent on wind direction., topography and surrounding conditionsa are more important effect. The experimental results show that: (1) ozone formation or disappearance depends on different HC, (2) the effect 2 of [NO]o is small for ozone photochemical reaction, but [O3] decreases with increasing [NO], (3) the descend rate of O3 depends on high humidity more than different kinds of HC or [NO], and (4) the descend amount of ozone increases with increasing humidity strongly, and the descend rate of ozone decreases with enhancing [O3]o. A statistical model was developed. The reaction rate and rate constant of ozone reaction with water were also obtained.
倍位元灰度影像產生器
本研究設計一新型的影像投射系統,可將影像顯示的灰度位元加倍,例如,顯示面板只需用4位元,即可顯示8位元的影像;亦能充分利用光路光源,增加光源使用率。此系統使用兩片相同灰度位元的顯示面板,此兩面板所顯示的影像經過灰度的重新處理,且各經由不同光源強度比值的光路合成後,其灰度分佈將可增為原來的平方倍。經模擬與實驗顯示,此種系統很輕易就能獲得預期目標。無論使用穿透式或反射式皆可應用於目前單片液晶面板之投影系統中;未來可望利用網板來表現灰度,應用於紅外線景物投射系統中,作為紅外線影像式尋標器靜態模擬時所需的高強度動態範圍與高解析度之影像產生器。In this study, a novel image generator utilized in a projecting system has been proposed; it can double the bits of gray-level for image display and enhance the efficiency of illumination of lamp in the optical path. With this system, a 4-bit display panel can achieve an 8-bit image display. Two display panels with same gray-level bits is adopted, images on them will be processed, and then go through different path with a proper intensity ratio. The gray level distribution of image displayed which the two images combined afterward, will be the square of that of original one. The results of simulations and experiments have approved to meet the requirements. No matter transmitting or reflective types can be applied to current projecting systems with single LCD panel. It is expected that a halftone-gray-level pattern will be suitable for this system to form an infrared scene projector, and to act as an image generator with high dynamic range and resolution for static simulation of infrared imaging seeker.