星島教室 科技與生活 馮穎匡博士 香港大學博士後研究員（人工智能）、 教育評議會執委 作者介紹 在炎熱乾燥的沙漠中，冰的存在似乎 是一個悖論。然而，遠在現代製冷技術誕 生之前，波斯人就已經掌握了在沙漠中大 規模製冰和儲存的技術，這一切歸功於一 種獨特的建築結構——Yakhchāl。 何謂「Yakhchāl」？ Yakhchāl，波斯語意為「冰 坑」，是一種用於儲存冰的古老建 築。這些建築通常建在沙漠地區， 其結構巧妙地利用了自然原理，實 現了在炎熱環境下的製冷效果。 Yakhchāl的建造材料主要包括泥 磚、沙子、黏土、蛋清、石灰、山 羊毛和灰等天然材料。這些材料混 合製成的Sarooj是一種具有極佳隔熱 性能的砂漿，能夠有效地阻隔外部 熱量的傳入。 Yakhchāl的歷史可以追溯至公 元前400至500年，在波斯帝國時期 就已廣泛應用。這些冰窖不僅用於 儲存冰塊，還用於冷藏食物、飲 料，甚至醫療。Yakhchāl的存在， 反映了古代波斯人對生活品質的 追求和對自然環境的深刻理解。在 波斯文化中，Yakhchāl不僅是一個 建築物，更是一種象徵。它代表了 波斯人的智慧、勤勞和對生活的熱 愛。Yakhchāl亦體現了波斯人在極 端環境下生存和發展的能力。 建築結構 Yakhchāl的建築結構獨具特 色，主要包括以下幾個部分： 1. 穹頂：頂部通常是一個巨大的圓 形穹頂，由厚重的泥磚層層疊砌 而成。穹頂的弧形設計有利於分 散重量，並增強建築的穩定性。 2. 地下儲藏室：地下部分是一個巨 大儲藏室，用於存放冰塊。儲 藏室的牆壁和地面都用Sarooj塗 抹，以確保良好的隔熱性能。 3. 風塔：一些Yakhchāl配有風塔， 風塔可利用風力將熱空氣排出， 引入冷空氣，加速降溫過程。 4. 坎兒井：許多Yakhchāl都與坎 兒井相連，坎兒井可以提供穩定 的水源，並將地下冷空氣引入 Yakhchāl。 製冰原理 Yakhchāl的工作原理主要基 於以下幾個方面的相互作用： 1. 隔熱：Sarooj的優異隔熱性能 是Yakhchāl能夠長時間保持 低溫的關鍵。Sarooj中的有機 物和無機物相互作用，形成 一個緻密的結構，能夠有效 地阻擋熱量的傳導。 2. 相變：冰的相變 過程是一個吸熱 過程，當冰融化 時，會吸收大量 的熱量，從而降 低周圍環境的溫 度。 3. 對流：Yakhchāl 內的空氣對流 可以加速熱量 的傳遞，將熱 空氣排出，引 入冷空氣。 4. 蒸發：水的蒸 發是一個吸熱 過程，當水蒸 發時，會帶走大量的熱量，從而 降低周圍環境的溫度。 其實Yakhchāl的工作原理，涉 及多個熱力學原理，包括熱傳導、 熱對流、熱輻射和相變等。 通過對這些原理的深入研究， 可更好地理解Yakhchāl的製冷機 制，並為現代建築節能設計提供借 鑑。 材料科學 Yakhchāl的建造材料Sarooj是一 種古老的建築材料，其成分和性能 至今仍是研究的熱點。研究表明， Sarooj中的有機物，如蛋清和山羊 毛，在提高材料的韌性和耐久 性方面起到了關鍵作用。此 外，Sarooj的孔隙結構亦 對其隔熱性能產生了 重要影響。 現代應用 Yakhchāl的設計理念和技術對 於現代建築節能具有重要啟示。許 多建築師和工程師正在研究如何將 Yakhchāl的原理應用於現代建築， 以實現建築的節能和可持續發展。 例如，利用Yakhchāl的隔熱技術可 設計出更加節能的建築，而利用 Yakhchāl的通風系統可以改善室內 空氣品質。 Yakhchāl是古代波斯人留給後 人的一筆寶貴文化遺產。這種獨特 的建築結構，不僅展示了古代文明 的智慧和創造力，也為我們提供了 研究傳統建築技術和可持續發展 的全新視角。通過對Yakhchāl的研 究，我們可以更好地了解人類在 惡劣環境下生存和發展的智 慧，並為未來的建築設計提 供新的思路。 小思考，大智慧 古代除了波斯人懂得在沙漠中 大規模製冰和儲存，我們中國的古 人又如何製冰呢？ 參考答案 古代中國人在炎熱的夏季同樣 有製冰的需求，雖然沒有波斯人那 樣壯觀的Yakhchāl，但他們亦發展 出獨特的製冰方法。 1. 硝石製冰法︰硝石是一種天然礦 物，具有吸熱降溫的作用。古人 將硝石溶解在水中，利用其溶解 過程的吸熱作用來降低水的溫 度，從而達到製冰的目的。 2. 沸水冷卻法︰這種方法看似矛 盾，但原理是利用熱脹冷縮的原 理。將燒開的水迅速倒入密封的 容器中，然後將容器放入冷水 中。隨着水溫的降低，容器內的 氣壓也會降低，水的冰點也會降 低，從而更容易結冰。 3. 利用地下水︰在一些地區，人們 會利用地下水的低溫來製冰。將 盛水的容器埋入地下，通過地下 的低溫來降低水的溫度，最終達 到製冰的目的。 從古代製冰方法，我們亦可作 以下延伸思考︰ 1. 現代意義：學習古代製冰技術， 對我們研究傳統建築、材料科 學、熱力學等方面具有重要意義。 2. 可持續發展：古代的製冰技術大 多利用自然資源，對環境影響較 小，值得我們借鑑。 3. 科學教育：古代製冰技術可作為 科普教育的素材，激發青少年對 科學的興趣。 本欄，由教育評 議會邀請資深中小學 老師、校長及大學講 師撰稿，旨在為學生 提供多元化的STEAM 學習材料，引發學生 探求知識的興趣，將 學習融入生活，培養 學生的世界觀、敏銳 的觸覺、積極學習的 態度。 ■Yakhchāl的製冰原理。 網上圖片 ■使用冰窖Yakhchāl來冷卻和儲存 冰塊的歷史，可追溯至公元前400 至500年。 網上圖片 讀社論學 英文 Kowloon Motor Bus (KMB) and Citybus have applied to the government for fare adjustments, reportedly by 6.5 and 9.5 per cent respectively. They cited reasons such as rising fuel & labour costs and changes in operating conditions. Their announcements sparked discontent among lawmakers and the public, as both companies raised fares only last May. Another increase seems overly frequent. The proposed increments also far exceed the accumulated inflation rate of about 3.4 per cent over the past two years. This creates a negative impression of making "the lion's share" demand. To safeguard public interest, the government must rigorously scrutinize these applications and not allow the companies to make exorbitant demands. Last May, all franchised bus companies received approval from the Executive Council to raise fares by 3.9 to seven per cent shortly after the end of the pandemic when many industries were still recovering. There was thus some understanding for the moderate increments . However, as the operat ing environment has improved in the past year and a half, higher fares are not welcome. In fact, stable or even declining international oil prices have posed no additional burden on the bus companies. The cost of higher wages to retain talents is an issue faced by many industries, not unique to bus companies. Moreover, the last wage increase was a modest 3.5 per cent, which is far from the current request. KMB has started making gains Are bus companies truly struggling? Data suggests otherwise. For KMB, its parent company, Transport International, reported a post-tax loss of $49.9 million in 2022 but it turned profitable in 2023 with a profit of $11.5 million. In the first half of this year, KMB even recorded a post-tax profit of $21.9 million, double from last year, thanks to revenue reaching as high as $3.44 billion, up by $185.7 million or 5.7 per cent. A big fare hike is thus unwise as it may drive passengers to the more competitive MTR. Bus companies can raise fares, but the increment must be reasonable and justified. In reviewing fare adjustments, the government considers several factors, including revenue changes since the last hikes as well as public affordability. There seems little reason for increases of 6.5 and 9.5 per cent - far higher than the inflation rate. Moreover, the hike requested by Citybus is three percentage points higher than KMB's, which seems even more unreasonable as it does not offer monthly passes like KMB. The "lion's share" request may be a game strategy of making a high initial demand that will be rejected, hoping the government will "negotiate down" to a level that is still high but appears less "extreme" and more acceptable. This strategy has been used before, all at public expense. It's worth noting that the government has been highly "supportive" of bus companies in recent years, including allowing them to save considerable tunnel fees after taking over the Western and Tai Lam Tunnels to improve their financial positions. It indeed has no responsibility to "ensure profits" for these private bus companies, but to protect public welfare. Therefore, fare hikes cannot be simply approved, and even if approved, the increment should not exceed inflation to avoid increasing public burden. The companies can also be required to partially offset the hikes and reduce the impact on passengers with Franchised Bus Toll Exemption Fund surpluses. Raise non-fare revenue For a long time, bus companies have been heavily dependent on fare revenue unlike the MTR, which generates substantial income through property projects. Bus companies need to transform and find ways to increase non-fare revenue. Legislators have previously suggested feasible measures such as taking more ads and setting up convenience stores at bus stations. The government should provide support for their operations and reduce the need for frequent fare hikes. 翻譯自2024年11月14日《星島日報》社論 （http://std.stheadline.com/） scrutinize (v) —— 審查 exorbitant (adj) —— 過分的 moderate (adj) —— 不過分的 unique (adj) —— 獨特的 struggling (adj) —— 艱難生存的 post-tax (adj) —— 稅後的 surplus (n) —— 盈餘 transform (v) —— 變革 the lion's share —— 最大份額 monthly pass —— 月票 game strategy —— 博弈手段 property project —— 地產項目 Roundtable lawmaker Michael Tien Puk-sun urged the administration to establ ish an annual fare-adjustment mechanism linked to inflation for franchised bus companies in the long run. He said authorities should control the fare increase range under 3.4 per cent - the inflation rate of the year - and approve the increase no earlier than May in 2025. 1. The word _____ in the first paragraph is the opposite of "satisfaction". 2. Bus companies received _____ from the Executive Council to raise fares in 2023. 3. In the passage, the word _____ means "fighting for survival". 4. The government is very _____ of bus companies. 5. According to the last paragraph, bus companies must find ways to increase _____ revenue. Answers 1. discontent 2. approval 3. struggling 4. supportive 5. non-fare & Q A Vocabulary Useful Terms Did you know? Peg bus fare hikes to inflation, no "lion's share" 翻譯︰George D6 侷芎 04.11.2025 星期五
RkJQdWJsaXNoZXIy ODc1MTYz