歡迎閱讀《週末科學版》!我們每週五都要為你介紹可以在家中進行的有趣科學實驗。你可以在《科學日誌》中記錄自己做了哪些活動,這樣就可以將所學的記錄下來,比較這些結果,也可以利用它們來設計新的實驗!先看一下《科學日誌》的點子再開始吧。展開實驗之前,記得要獲得大人的同意喔!
A lot of rock bits are broken up as a drill bores through the earth. A special system that makes use of drilling mud is used to remove those bits so that they don’t get in the way. Today we’re going to look at why drilling mud needs to have a high viscosity.
What you will need:
A tall cup (this will represent the borehole)
A straw (this will represent the drill bit)
Sand (this will represent the rock bits)
Water (this is a liquid with a low viscosity)
Shampoo (this has a much higher viscosity than water)
► Put some sand into the cup and fill it with water. Wait for the water to penetrate through the sand.
► Place the straw into the cup so that it touches the bottom. Blow for a few seconds and then look at what the sand does.
► Repeat the above steps, but this time use shampoo instead of water. What’s the difference?
(MICHAEL KEARNEY, STAFF WRITER)
鑿孔機在地表鑽洞時,土石會破碎成很多小碎石,這時就會利用一種運用鑽井液的特殊系統來清掉這些碎石,以免它們妨礙鑿孔機工作。今天我們要來看看為什麼需要高黏度的鑽井液。
所需材料︰
一個細高的杯子(用來當作鑽井)
一根吸管(用來當作鑿孔器)
沙子(用來當作碎石塊)
水(不黏稠的液體)
洗髮精(比水黏稠的液體)
► 把一些沙子放入杯中後再加滿水,等水完全滲入底下的沙子。
► 把吸管放入杯中,直到碰到杯底,對著吸管吹氣數秒,然後觀察看看沙子有什麼變化。
► 重複上述步驟,但這次我們用洗髮精取代水,結果會有什麼不同?
(翻譯︰袁星塵)
What's the science? 科學原理
Viscosity describes a liquid’s resistance to flow. Water flows easily, so it has a low viscosity. Shampoo doesn’t flow as easily, so it has a higher viscosity. Drilling mud has to have a high viscosity in order to suspend rock bits so they can be carried upwards.
黏性就是液體流動的阻力。水很容易流動,所以它的黏性很低;洗髮精不容易流動,所以黏性較高。鑽井液的黏性必須很高,才能支撐碎石塊懸浮其中,進而把它們送出井外。
當你用水做實驗時,沙子浮起來沒多久後立刻又沉下去;水的黏性很低,所以沒辦法讓沙礫懸浮在其中。
當你用洗髮精做實驗時,沙子會浮起,但重新下沉的速度卻緩慢�?F洗髮精的黏性高,所以它防止沙子沉回杯底的效果較好。水不能作為很好的鑽井液,但洗髮精應該是種不錯的選擇。
Further ideas 進階點子
Cornstarch mixed with water has some strange properties. Its viscosity depends on how much pressure is applied.
Add two parts cornstarch to one part water and stir slowly. Gradually add more water and continue to stir the mixture until it acts like a liquid when you stir it slowly and a solid when you stir it quickly. Try kneading the mixture into a ball. If you continuously apply force to the ball, it will act like a solid, but once you stop applying force, the ball will “melt” before your eyes.
攪拌後的太白粉水有一些奇怪的特性,它的黏性取決於它所受的壓力大小。
用二比一的比例調和太白粉和水後輕輕攪拌,再慢慢加入一些水,持續攪拌;若是你攪拌的速度很慢,它會呈液體狀,但要是你攪拌的速度很快,它就呈固體狀。試試看把混合物搓成一顆小球,如果你持續用力捏它,它就會呈現固態;但是一旦你不再用力,它就會在你面前「溶化」。
Rice is essential to Japanese culture, tradition and politics. People take pride in the oval-shaped sticky Japonica grain, which is still a staple even though total consumption has fallen over the decades. But since last summer, prices have soared as supplies have fallen short of demand. The government has long paid farmers to cut back on rice acreage, and change to other crops to keep rice prices relatively high. To cope with shortfalls this year, the government has released rice reserves. But the grain has been slow to reach supermarket shelves. Anger over that was part of the reason the Agriculture Minister
Step into any corner of Turkiye, and you’ll likely encounter the iconic “Evil Eye,” known as “nazar boncu?u” in Turkish. This striking blue glass ornament is shaped like an eye with concentric circles of dark blue, white, and light blue. While its name in English suggests something threatening, it’s actually a charm designed to ward off misfortune. The origins of the nazar boncu?u can be traced back to ancient Mediterranean and Middle Eastern traditions. The word nazar comes from Arabic, meaning “gaze,” while boncu?u translates to “bead” in Turkish. Central to the nazar boncu?u’s mythology is the idea that
A: Wow, Les Miserables Staged Concert Spectacular is visiting Taiwan for the first time. B: Isn’t Les Miserables often praised as one of the world’s four greatest musicals? A: Yup. Its concert is touring Taipei from tonight to July 6, and Kaohsiung between July 10 and 27. B: The English version of the French musical, based on writer Victor Hugo’s masterpiece, has been a huge success throughout the four decades since its debut in 1985. A: The musical has never toured Taiwan, but going to the concert sounds like fun, too. A: 哇,音樂劇《悲慘世界》紀念版音樂會首度來台巡演! B: 《悲慘世界》……它不是常被譽為全球四大名劇之一嗎? A: 對啊音樂會將從今晚到7月6日在台北演出,從7月10日到27日在高雄演出。 B: 這部法文音樂劇的英文版,改編自維克多雨果的同名小說,自1985年首演以來,在過去40年造成轟動。 A:
Continued from yesterday(延續自昨日) https://www.taipeitimes.com/News/lang In 1946, the company adopted the name 7-Eleven to reflect its newly extended __3__, from 7am to 11pm, a novel concept at the time. As a rapidly growing company, it began offering franchise opportunities in the 1960s. In 1974, the first 7-Eleven in Japan was opened by the supermarket company Ito-Yokado. The Japanese franchises were __4__ successful that by 1991, Ito-Yokado was able to acquire a 70 percent stake in Southland Corporation. Its investments eventually resulted in full ownership of 7-Eleven, which paved the way for the Japanese company to enter the international market. Since then, 7-Eleven