Newsletter No. 549/550

05 # 5 4 9 / 5 5 0 | 0 4 . 0 1 . 2 0 2 0 Photo by ISO 掃描閱讀全文 M. Mak 並不足夠。郭教授接連親赴汕頭和廈門調查， 記錄數百個異讀字，並記下這些字在詞彙層 面上的組合。 本身是中大粵語研究中心主任的郭教授，也 研究粵語、客家語等南方語言，閩南語只是研 究計劃的一部分。他期望進一步探索各種南 方語言的形成過程及它們之間的關係。 現時全球約有五千萬人以閩南語為母語，集中在福建省東南 部、廣東省潮汕地區和雷州半島、海南沿岸、浙江省東南部， 以及台灣。香港的原住民中，也有一小部分人說閩南語。 郭教授並非祖籍福建，母語也不是閩南語，而且是傳統語言 文字學出身，研究路上突然轉換跑道，源於老師 張雙慶 教授 的薰陶。張教授在研究期間收集了大量閩南語料，一直未發 表，郭教授便運用這些語料展開研究。然而，單靠前人的成果 無論是甚麼語言，一字一音，都盛載文化、肩負歷史；研究 語言文字，就是感受文化、探索歷史。中國語言及文學系 郭必之 教授研究閩南語的文白異讀現象，把數百個異讀字逐 一發掘，製成詞表，獲得2018至19年度青年學者研究成就。 文白異讀是漢語分支的特色，文讀音便是我們讀書時所使 用的讀音，白讀音就是平時說話所用的讀音。以粵語為例， 「驚慌」的「驚」是文讀音，讀 ging 1 ；我們口語說的「好驚」， 「驚」讀作 geng 1 ，就是白讀音。 閩南語的文白異讀現象更普遍，牽涉的字超過一千五百個， 而粵語的異讀字只不過三百個左右。閩南語的異讀發展亦 更多元化，一個字可以有多個白讀音，而且能區別字義。 「節」字文讀音是 tsiat 7 ，白讀音則有兩個：中秋節的「節」作 tsue ʔ 7 ，關節的「節」作 tsat 7 。更特別的是，閩南語可以用同 一個字的文白異讀構詞，例如指食物的「食食（ tsia ʔ 8 sit 8 ）」， 前字白讀，後字文讀，而表示食指的「指指（ ki 3 tsãi 3 ）」，兩個 「指」字是白讀的不同形式。 文白異讀現象，可以溯源至隋唐以後。中國北方是歷朝帝都 所在，北方話被視為權威。南方各地的民眾模仿北方話讀書 認字，於是形成文讀音，各地固有的讀音則是白讀音。因此， 白讀的歷史比文讀更為久遠。郭教授說：「閩南語的歷史比 粵語更長，而且地理上遠離北方，讀音跟北方話的差距更 大，文白異讀的情況更普遍。」 Identical in Shape, but not in Sound 文白異讀面面觀 Dr. Gao. Professor Liao added, ‘The design is important—it is the MFC slices combined with the innovative design, a mechanical structure which makes it work.’ And there’s still one crowning feature: the invention produces energy at no cost to us. The research team had performed experiments of walking with and without the harvester, and found out it does not increase the users’ metabolic effort. Using ball joints at the bearings of the thigh and shank fixing bands, the harvester caters to all knee movements, issuing even more energy in intense activities like running and in soccer games. And as demonstrated by Dr. Gao on the spot, it is easy and comfortable to wear. Taking five months to develop, the energy harvester we now see is the third generation, and the team is looking to improve its energy efficiency through altering its mechanical structure or the palette of composites in the slices. They also seek to enhance the design, increase its comfort and lower the cost. Indeed, after its publication as a featured article in Applied Physics Letters , a top journal in applied physics and in energy harvesting in July 2019, the team has been greeted with wide media and commercial interests, and enquiries are flying in for possibilities to commercialize the device, say, to integrate the design into clothing. With this in view, they are now filing patents in the US and China. And in two years’ time, we will see the prototype developed into a full-fledged product in the market, soothing our nerves and affording us the boon of streaming energy at no extra effort. Amy L. thus transformed to linear motion along the slider,’ explained Professor Liao. And this is not the end of the story: a carbon fibre plate with smart materials on it arches over the design, with one end of it hinged on the thigh fixing band and another on the moving slider. The slider’s movement arising from our gait would cause the carbon fibre plate to bend and the smart materials on it would deform, converting the pressure it receives into electricity. Such smart materials are macro-fibre composite (MFC) slices that are piezoelectric in nature, with piezoelectric referring to its ability to convert mechanical energy into electrical energy or vice versa. Here, it means the materials can generate electricity once they come across any mechanical effects, in this case pressure and deformation. Placed side by side on the bending beam, the two MFC slices are available on the market and cost $700 each. ‘In mass production, the cost can be lowered,’ Professor Liao said. At a normal walking speed of 4 km per hour, the MFC human knee energy harvester generates 1.6 milliwatts of power, i.e., 1.6 millijoules per second. This would be sufficient to power small devices such as health monitoring equipment and GPS devices. The Huawei smart band, to give you an idea, consumes one milliwatt on average. The harvester would therefore be able to power it. ‘The power generated by the harvester can either be stored, or put through to other portable and wearable appliances as in the Internet of Things. It offers a good solution to the battery problem, as it allows us to utilize energy locally. In mountaineering, for example, where charging may be a problem, we do not have to rely on batteries, as we can get energy direct from our own motion. It would be good for safety and emergency purposes,’ said the professor. What’s more, this modern-day talaria is a lightweight one, weighing only 307g. ‘It should be the lightest among the current energy harvesters, and the first one to combine the strengths of smart materials and a mechanical structure,’ said A nxiety over dying battery is a syndrome of our times. The fast dwindling life juice in that tiny battery icon on our smartphones fuels our fears, and it is only when we have managed to charge them our peace of mind is restored—actually, the pain caused by the low percentage feels so sharp and ubiquitous, few of us do not leave our phone plugged even when it hits the full charge. Thanks to the ingenious invention by mechanical engineers led by Prof. Liao Wei-hsin (left, top photo), chairman of Department of Mechanical and Automation Engineering, our paranoia about charging will soon come to an end. And the cure they discovered lies nowhere other than in our own knees; by donning the human knee energy harvester which flaunts the use of smart materials and an innovative design, we can duly capture the kinetic energy generated by the joint, have it converted into electricity and power electronics simply by walking, any time any place. ‘The human body is a rich source of energy, especially kinetic energy, which can be harvested for the generation of electricity,’ remarked Dr. Gao Fei (right, top photo), postdoctoral fellow in the Department of Mechanical and Automation Engineering who is the main inventor. ‘The human knee joint has a larger range of motion than other lower limb joints such as ankle and hip. Moreover, the knee’s motion primarily occurs in a sagittal plane, which makes the capture of kinetic energy by the harvester much easier.’ To capture the knee’s energy and convert it into electricity, the human motion researchers fashion their human knee energy harvester after the slider-crank mechanism (figure 1). To begin with, we have two fixing bands at the thigh and shank which fasten the device to our limb. From the thigh and shank fixing bands extend the thigh and shank links, respectively, which meet at a movable bearing at the knee. A linear guide, moreover, connects the thigh and shank links at their ends at the corresponding fixing bands, and a slider glides along it. ‘When walking, our leg flexes and extends, causing the slider to move back and forth. The rotary motion of the knee is 學 術 探 奇 / S cholarly P ursuits