全國中小學科展

2008年

昆蟲也會大小眼!?

本研究目的主要在瞭解昆蟲的複眼(compound eyes)結構,比較晝行性與夜行性昆蟲複眼之差異,探討其視覺遠近和複眼結構的關連,及進一步觀察其對不同波長光源反應的差異。本實驗使用反射式及倒立式顯微鏡來觀察複眼及其小眼的結構,及觀察其成像情形,並使用攝影式接觸分析儀與放大管來探討視覺遠近和小眼表面曲率之關連,另外在暗室利用不同波長的光源照射蝴蝶以觀察其反應。實驗結果顯示複眼是由數千至數萬個小眼組成,小眼表面曲率半徑隨選用物種在25.3μm 至117.6μm 之間,蜻蜓複眼上半部和下半部小眼曲率半徑分別為30.6μm、117.6μm,印證了蜻蜓複眼上看遠下看近的說法,也發現蝦子小眼是正方形,其他實驗物種則皆為六邊形,而蝴蝶對光的反應程度則是隨波長漸增而遞減。The main purpose of this study is to understand the structure of the compound eye of insects, to compare the difference between the diurnal insect’s compound eye (apposition eye) and that of the nocturnal insect (superposition eye), to explore the relationship between the vision and the structure of the compound eye, and to observe the eye’s reaction to the different light wave length. In this study, a microscope (OLYMPUS BX51M) and an inverted microscope (OLYMPUS 1X71) were used to observe the structure of the compound eye and its ommatidia, as well as the resulting image. A contact angle measuring instrument (Dataphyscis OCA 20) and a microscope (Mitutoyo NAVITAR) were used to determine the connection between the vision distance and the facet curvature of ommatidia. The butterfly’s reaction to the light source with different wave length was also observed in a darkroom. It was observed that the compound eye of insects is composed of more than a thousand ommatidia. Among the subject insects, the facet curvature radius of their ommatidia ranged from 25.3μm to 117.6μm. The radius of the top and bottom half of a dragonfly is 30.6μm and 117.6μm. It confirms a scientific finding that dragonfly’s top compound eye focuses farther than the bottom half. The facet of each ommatidium observed is hexagonal in insects compared with the square shape found in the eye structure of shrimp. Regarding the reaction to light of the butterfly eye; the reaction decreased when the light wave length increased.

Shock Induced Battery

a. Purpose of the Research Evidence has shown that people are becoming more aware of environmental protection than in the past. Not only has the government made every effort to implement the policies of environmental protection, but Hong Kong citizens are also more willing to cooperate and help out. However, when it comes to conservation of energy and reduction of wastage, many people still regard it as a burden and they just take it lightly. In fact, environmental protection can be achieved in a convenient and simple way. We can easily put in practice in our daily lives. Because of this, we would like to introduce our invention - “shock Induced battery” by using our knowledge of Physics. b. Procedures The “Shock Induced battery” makes use of locomotion of human bodies to generate electricity. The electrical current generated from the specially designed generator will pass through the diode bridges, which adjust the current to one direction. This enables the electrical energy to be stored in the capacitor. This energy will be released when the battery is correctly connected to a circuit with a switch and a resistor. One of the features of the battery is that it is portable. It is mainly used to charge up electrical devices. But it is hoped that it will replace non-chargeable cells one day, and can directly be used in any electrical devices. In fact, our ultimate goal is to reduce the wastage of materials for making the cells, and to solve the problem of disposal of these cells. c. Data The induced a.c. voltage is full-wave rectified by the diode bridge. d. Conclusions In a word, we are trying to provide a chance for people to put environmental protection in practice, so as to raise the awareness of people about environmental protection. After all, high-tech products only solve the power-saving problem to a certain extent, but it is the awareness and the initiatives of the public which matter. We are convinced that environmental protection brings fun to your daily lives, as you will find practices on environmental protection both convenient and simple.

Construction of a Mechanical Prototype of a Microtremor Recorder

Ambient vibration, the movement of the ground caused by transient objects such as the relative to values obtained using the commercial recorder. The natural ambient vibration of a control site was simultaneously obtained using the mechanical prototype and the commercial recorder, which were situated next to each other during the actual recording. Moreover, both sensors were used to record a control stimulus for a constant amount of time. The data obtained from these subparts were processed using WinWaveShot which quantified and presented ambient vibration as waves. The deviations of the maximum and minimum amplitudes, mode and median values of these waves, as graphed by DADiSP2002, was performed to verify the accuracy or reliability of the prototype. These graphs were converted to their DFT graphs and histograms, with accompanying converted wave properties which characterized the predominant frequency. Based from the results, the recordings obtained from the mAVR are proportional from the ones obtained from the eAVR. Therefore, the mechanical prototype is capable of recording the predominant frequency of a site. The prototype, when improved, is a potential alternative to commercial sensors since it is able to record actual movements and its scale is proportional to the scale of the eAVR. Since the prototype was constructed and can be reproduced from readily available and inexpensive materials, ambient vibration analysis can be used more commonly by architects and engineers for construction purposes. To verify the reliability of the values obtained using the prototype, the ambient vibration of other sites must be recorded and compared to those using the eAVR. wind, sounds and human activities, is one major site effect evaluation method presently used. The respective predominant frequencies of a site and the structures above it obtained using this method serve as reference to the renovation and/or construction of structures. Predominant frequencies of the landmass and the structures above it should be non-identical to avoid prolonged shaking with the occurrence of an extensive movement of the ground as dictated by resonance effect. Since electronic ambient vibration or microtremor recorders, specifically their sensors, are expensive and inaccessible, a mechanical prototype of such device was designed and constructed. The proposed design of the mechanical ambient vibration recorder (mAVR) was mainly based on the IRIS Seismograph which makes use of the principle of electromagnetic induction. The relationship between ground motion and the movement of the prototype lever, which is a direct proportion, was the concept highlighted by the prototype’s mechanism. After the design of the mAVR prototype was finalized, its assembly, which consisted of the calibration of the solenoid and the inertial mass, was performed. The calibration of the solenoid was based on the voltage output of its solenoid based on the number of turns while the inertial mass was determined based on the equilibrium level of the prototype lever. Having proven the mAVR’s capacity to function by simulating stimulus, the testing of its accuracy was done with two setups: recording of (1) natural and (2) induced ambient vibration. This tested the prototype’s accuracy

SEAWEED ON THE NAMIBIA COAST EXTRACTION OF AGAR & USE OF KELP AS FERTILIZER

In Swakopmund we have a problem with seaweed deposits on our beaches. Tons of seaweed are throwni away yearly. The reason I did this project was to see if the seaweed on the Namibian coast can he used instead of just being thrown away.Seaweed is a rich source of natural minerals and vitamins such as calcium, potassium iodine and also Vitamin A, BI and K. The seaweed on our coastline cannot he eaten as the salt content is too high. Seaweed is a marine algae that works like a sponge absorbing nutrients and minerals from the water.I extracted agar (a jelly) from red seaweed called(GracilariaVerrucosa). I dried the agar and seaweed, and I also grew mushroom spawns and bacteria on the agar plates. Secondly, I researched the possibility of using kelp (Laminaria Pallida), as fertilizer and livestock supplements. The unemployment rate in Namibia is very high. With adequate financial resources and proper marketing, seaweed can he used to increase the economy. We can market the agar to pharmaceutical and cosmetic companies, and also supply it to the university for students in Biology to grow bacteria and other micro organisms. The ferti lizer can be used to boost agriculture in Namibia. It is cheap and the farmers will he able to p1 ant vegetables with better nutritional value.All this was done to promote of biggest natural resource to create more work and to find a way for the less fortunate to create a better life for themselves.

溫泉中的秘密

The experiment was primarily focused on studying whether the enzymes from different bacterial species collected in various hot spring areas still exhibited activities at high temperatures. A further study would be conducted on analyzing the unique characteristics universally found in the genes of selected bacteria. First, hot spring samples were collected form Peitou and Wulai, and then cultured on the PY, PTG, MFB, and TS media in the laboratory. After the broth media growing with thermophilic bacteria, a series of continuous dilution method and solid-plate spreading were applied to separate these bacterial clones. The genomic DNA of the selected bacteria was extracted and used to analyze subtilisin-like gene by polymerase chain reaction (PCR) and electrophoresis. Finally, we examined the six selected thermophilic bacteria with the enzymatic activities of fibrin- and milk-protein degradation. We successfully concluded the experiment by proving that these thermophilic bacteria still exhibited significant enzymatic activitives in the high-temperature environments. The results of this experiment can be applied in numerous fields, for example, thrombus treatment and food processing, and a more in-depth study shall warrant the due consideration. 這次的實驗,主要是研究在不同的溫泉區中所採集不同種類細菌,是否酵素在高溫下仍具活性,如果有,再進而研究它們的基因有何特別的共同之處。首先,我分別自北投和烏來採集水樣,到實驗室後再以PY、PTG、MFB 和TS 四種培養基做細菌的培養,接著再利用連續稀釋和固態塗抹來做細菌的分離。經過挑選和培養之高溫菌直接進行DNA 的抽取,並利用「聚合?鏈反應」和「電泳跑膠」技術分析其類似蛋白質分解酵素subtilisin 基因。另外,本研究同時針對所選定之6 株高溫細菌利用血栓和牛奶蛋白來測試其蛋白質分解酵素的活性。由以上實驗結果可以證明某些細菌在高溫的環境下酵素仍具活性。這次在高溫菌的實驗結論,可應用在很多地方,例如:血栓的治療、在高溫下食品處理‧‧‧等,應用相當廣泛。

烷類數位密碼

本研究主題主要是解決化學上複雜同分異構物的繪製以及其命名,因為物質在結構複雜時其同分異構物變化之多令人難以捉摸,於是我應用電腦強大的邏輯處理以及運算判斷的能力來讓電腦繪製。以下是我想達成的目的:(1)排列出分子式的同分異構物(2)顯示出同分異構物之示性式、結構式(3)預知尚未創造出物質的性質研究中我創造出以下原則讓我方便達成研究(1) 數位密碼:為了讓電腦方便執行我使用數碼的方式表達各種同分異構物(2) 五大原則:此原則能讓不僅是電腦甚至是各個要繪製同分異構物的人都能有架構的繪製,不會遺漏任何的組成。(3) 3D顯示:透過X3D軟體的協助我能讓使用者透過立體的方式了解到物質的結構。The purpose of this research is to solve the problem of Isomer’s structure drawing and named problem. It’s hard to predict the status of complex Isomers, so we use the powerful logic and calculational ability of computer to draw the structure of Isomers. The following points is the goal that we want to reach (1) Arrange the structure of the Isomer’s formula (2) Show structural formula of Isomers (3) Predict the chemistry of things that haven’t been created During our research, we create the following principle to help us do the research (1) Digital Codes: In order to let the computer to run the process, we use digital codes to express all the Isomer’s formula. (2) The “5 Rules”: The 5 rules can help not only computers but all the people who try to draw the structure of Isomers without losing any of compositions. (3) 3D Display: Helping our user to understand the structures of materials with the 3D images producing by the “X3D”.

視覺中的光學現象

人眼所見點光源四週的光芒(我們稱為"星星長角"),夜間瞇眼時所見向上下方向射的特別長的光芒(我們稱之為"炫光萬丈"),這二種視覺中的光學現象無法用相機拍攝,但眼睛卻能夠看見。書上及網路上均無法找到合理的解釋。因此,我們設計了數個實驗來研究這些光學現象的成因。我們發現了星星長角的成因是由光對眼睛表面刮痕的繞射和光對眼睫毛的繞射雙重原因所產生。而炫光萬丈的成因則是光線經過眼球表面淚膜層的部分反射及部分折射所造成。The purpose of the research is to verify possible reasons of some optical phenomenon in human vision, including the star shape of a dot light source and glare upward or downward when one narrowing his/her eyes. These optical phenomenon can be seen by naked eyes but can not be taken photos with a camera. We find no detailed explains which can explain the cause of glare upward or downward on the internet or in books. So we designed several experiments trying to find out the cause of these optical phenomenon . In experiments, we figured out that diffractions by notches on the surface of eyes and eyelashes are both responsible for the star shape of a dot light source. The cause of glare when narrowing eyes is that partial reflection and partial refraction of light take place between boundary of air and tear film and boundary of tear film and cornea. The appearance of glare is closely related to the thickness of the tear film . When we narrow our eyes , the tear film is thicker. The thicker the tear film is ; the longer the glare is .Also, bended extent influence the length of glare. We figured out that the more bended the tear film is ; the longer the glare is.

Technology of web site advancement

Internet by its content represents a fountain of information, while from the point of view of its arrangement it is a huge dump. There are an enormous number of web sites. Multiple web sites are commercially directed, i.e. are aimed at profit earning. As profit depends on the number of visits to web site, no visitors means no profit. So, to obtain more orders, web site producers should first of all ensure good inflow of visitors (web site attendance). Every year this task becomes more and more critical for commercial web site owners (and not only for them), as the number of similar content web sites increases steadily along with competition intensifying correspondingly. The process of establishing conditions to attract more visitors is called web site advancement. The present paper discusses various ways of how to increase the number of web site visitors, it also describes the particular process of "Theater to Children" (www.teatrbaby.ru) web site advancement. Based on the paper outcomes a CD multimedia manual "Technology of web site advancement" has been developed that will help web site producers to achieve good attendance for their network resources. As the purpose of web site advancement is visitor number increase then the main criterion of web site advancement efficiency should be the number of visitors for a certain time period, e.g. for 24 hours, a week or a month. Taking into consideration that about 80% of Internet users retrieve information through search systems, the major growth of visitors will occur owing to the enhancement of web site visibility in search systems.

The Beam of Hope

As the most dominant species on planet Earth's surface, humans have become the sole protectors of the planet, in charge of keeping it hospitable for billions of species. However, a swift look around Egypt's streets in contemporary 2007 showed proof of our exploitive use of fossil-fuels. Provoked by such a scene, I set out to discover the negatives of fossil-fuel consumption that more than 2 million websites were ready to detail. The increased CO2 emission, due to fossil-fuel use, is contributing to the greenhouse-effect, causing global-warming and thus leading to climate-change. This affects biodiversity by causing the eventual extinction of species, thus upsetting food-chains and affecting humanity in the long-run. Statistically 40 more years of consumption are left if the current rate-of-consumption persists. My proposal is to use solar-energy as an alternative power-source. Two requirements must be fulfilled: it must hold research potential and shouldn't suffer from problems associated with fossilfuels. 3rd-generation nanocrystalline dye-sensitised solar-cells have a conductive-glass-electrode coated with titanium-dioxide, then a layer of dye on it for light-absorption, electrolyte and finally a counterelectrode coated with graphite.\r In the dye-experiments, dyes extracted from fruits & vegetables, and the wavelengths of visible-lightspectra that they absorb, were examined using a UV-spectrophotometer. The solvent for the extraction-process was tested and ethanol was better than water because it actively extracts the dye while water doesn't help and contains ions that alter the dye's absorption-abilities. I combined 2 dyes: chlorophyll (absorbs the red & violet areas in spectrum) with blackberry (absorbs the green area) thus enabling the solar-cell to absorb the entire spectrum and maximising its power-reading. I investigated whether the dyes should be freshly-mixed or combined earlier (and used every time to build the cell). Freshly-mixing dyes is better because that stops the enzymes that were extracted out with the chlorophyll from denaturing blackberry's anthocyanins and rendering them dysfunctional thus the dyes work better maximising the power. Testing the dye-combination's concentration showed that the 6.25% concentration is the best because it can coat the TiO2 with a single-layer of dye instead of high concentrations that give multiple layers of dye which doesn't give good electron transition or low ones that don't give enough dye which means a lower amount of electrons are being excited and thus less power. In the material-section, anatase and rutile, TiO2's 2 major constituents (structurally identical but with different crystal-orientation), were compared and anatase proved itself better because of its smoother conduction-band. Different anatase particle sizes were examined and the smaller particles (4 nm) were better because of increased surface-area. I investigated the ways of coating the counterelectrode and found that using carbon-paste is the best. Ultimately my solar-cell's power-reading increased from 2.04 nW to 6.41 μW which is 3142 times the initial reading, a dramatic increase for a solar-cell whose size doesn't exceed 4 cm2. This proved the great research potential held by solar-energy. After extensive comparisons between the ups and downs of both fossil-fuels and solar-energy, solar-energy clearly proved itself the perfect alternative for powering our future.

明察秋毫-動態測微器

The purpose of this research is to create a device that is able to precisely measure small dynamic changes which cannot be recognized by the human eyes. The Vernier Caliper and the screw micrometer are common tools used to precisely measure lengths of objects. However, things which are measured by the Vernier Caliper or the screw micrometer have to be in a solid state, and the shape cannot be changed. By applying the light lever principle on Lego bricks, this research uses the LabVIEW graphical programming system to design a device which is able to automatically measure small dynamic changes. The precision of this device is higher than that of the Vernier Caliper and the screw micrometer. Moreover, this device is able to precisely detect the small dynamic changes of solids and liquids as well. Through numerous tests, the least count of the device can reach the level of 10-3cm. Also, this device has successfully measured small changes, such as the height of the liquid surface by one drop of water, the evaporation of water in one minute, and the growth of a plant in one hour. By popularizing this device, people will be able to precisely measure small dynamic changes which are difficult to be measured in a short time.