吶喊為挪威畫家愛德華·孟克的作品，其呼喊的「怪異」樣貌形象非常鮮明。987Please respect copyright.ＰＥＮＡＮＡSjs2rv6tXS
987Please respect copyright.ＰＥＮＡＮＡo18pkMw66e
987Please respect copyright.ＰＥＮＡＮＡxSa4bfbR9g
他本人在1893至1916年畫出多個版本，而其中一幅展示在孟克美術館（Munch Museum)的版本因多處黃色地方出現變白及脫落跡象關係（圖1的數字標記區域），自2006年起已甚少公開示人。987Please respect copyright.ＰＥＮＡＮＡU6ljwcBhlr
987Please respect copyright.ＰＥＮＡＮＡUgItVT98lj
作品現時正處於光線陰淡、攝氏18度、相對濕度約50%的環境備受保護。987Please respect copyright.ＰＥＮＡＮＡpZejQNlrNz
987Please respect copyright.ＰＥＮＡＮＡ4R1IW20S7x
987Please respect copyright.ＰＥＮＡＮＡU5EqA8Xbpl
（圖2）為了解箇中顏料變色及脫落的機制，有科學家對吶喊作品作出深入研究，並在近日發表文章講述得出的結果（Ref1)。987Please respect copyright.ＰＥＮＡＮＡEXvgUHZYjT
987Please respect copyright.ＰＥＮＡＮＡsgV1etZdyr
987Please respect copyright.ＰＥＮＡＮＡbOP1NUUAPC
Cadmium sulfide，為該時期常用作為黃色顏料的化學物。987Please respect copyright.ＰＥＮＡＮＡe1dHVtHg0V
987Please respect copyright.ＰＥＮＡＮＡ03WHniwpvJ
同期的文森·梵谷 (Vincent van Gogh)、詹姆斯・恩索 (James Ensor)和亨利·馬諦斯(Henri Matisse)均有利用這種化學物所製成的顏料，而相關的作品亦有出現黃色顏料變白的現象。987Please respect copyright.ＰＥＮＡＮＡfTKPUT2U1F
987Please respect copyright.ＰＥＮＡＮＡSchbA9FvBb
該時期主要有兩種方式製作Cadmium sulfide，分別為Dry及Wet Method。987Please respect copyright.ＰＥＮＡＮＡypnPAAYok4
987Please respect copyright.ＰＥＮＡＮＡsNLVGO1U6P
Dry Method為以300°C至600°C及零氧氣的方式，加上大量硫元素(Sulphur)調配Cadmium sulfide的方式，得出的成品相對上較為純正。987Please respect copyright.ＰＥＮＡＮＡjE9vFI9xBq
987Please respect copyright.ＰＥＮＡＮＡAFwQ1F710G
Wet Method為將不同的化學物混合在一起（如圖中所示），再以沉澱的方式獲取固體Cadmium sulfide。987Please respect copyright.ＰＥＮＡＮＡGWpAE3azIM
基於當時技術相對上不太先進，最終的產品會含有較多雜質及副產品。987Please respect copyright.ＰＥＮＡＮＡusrUkBC3rF
987Please respect copyright.ＰＥＮＡＮＡJeYSnSC9vU
（圖3）科學家在文中嘗試挖取微量的吶喊畫碎粒，再利用各種技術檢測畫中的化學物成份。987Please respect copyright.ＰＥＮＡＮＡXYUXWsKNtr
987Please respect copyright.ＰＥＮＡＮＡWO4cQEocha
987Please respect copyright.ＰＥＮＡＮＡzzRNV3mOeO
圖3中間的圖片，其紅點代表黃色顏料Cadmium sulfide的存在。987Please respect copyright.ＰＥＮＡＮＡe3PvFjWA71
987Please respect copyright.ＰＥＮＡＮＡKBYNLUcGuD
下方的圖片，其三種顏色的出現分別代表Wet Method的副產物。987Please respect copyright.ＰＥＮＡＮＡAI6AlQKapF
987Please respect copyright.ＰＥＮＡＮＡP8M1e759um
紅點:Cd(OH)Cl987Please respect copyright.ＰＥＮＡＮＡb8RNliW6AA
綠點:CdSO4987Please respect copyright.ＰＥＮＡＮＡriEek15MXu
藍點:CdCO3987Please respect copyright.ＰＥＮＡＮＡH4XS8nvgMP
987Please respect copyright.ＰＥＮＡＮＡ7wpqM1fjoj
這三種副產物，在長久而來的知識中已被確認是顏料變色及脫落的兇手，與吶喊作品所出現的現象不謀而合。987Please respect copyright.ＰＥＮＡＮＡom41mkMWjw
987Please respect copyright.ＰＥＮＡＮＡYfHSg2RCIe
（圖4）為進一步了解顏料變色的現象，他們找來了吶喊畫同期帶有黃色顏料的作品(他們已7914數字命名樣本)。987Please respect copyright.ＰＥＮＡＮＡwaByz6ymeV
987Please respect copyright.ＰＥＮＡＮＡzdPraJfOVa
987Please respect copyright.ＰＥＮＡＮＡTWZLhc6Kyj
拿取畫中碎片後，（圖4左方）他們同樣發現裡頭含有Wet Method的副產物（綠點）。987Please respect copyright.ＰＥＮＡＮＡkmYGK21AUT
987Please respect copyright.ＰＥＮＡＮＡIeNSZvXFd7
為了解環境因素對於顏料變色的影響，他們對另一塊畫碎用上90 日相對濕度≥ 95%，攝氏為40°C，無光環境來模仿歲月的摧殘。987Please respect copyright.ＰＥＮＡＮＡFtxOmkrJBq
987Please respect copyright.ＰＥＮＡＮＡWnNkHmd8g7
他們發現得到Wet Method的副產物Cd(OH)Cl（綠點）數量大增且集中在一起，其目測得到黃色顏料變白的現象發生。987Please respect copyright.ＰＥＮＡＮＡHCUtkFFvYO
987Please respect copyright.ＰＥＮＡＮＡDjg4kmycEX
然而，用上用上90 日相對濕度=45%，攝氏為30°C，300W光源直接照射的環境來模仿歲月摧殘的話，則沒有感測得到Wet Method副產物的產生和顏料變色現象發生。987Please respect copyright.ＰＥＮＡＮＡJgOtQAAmvw
987Please respect copyright.ＰＥＮＡＮＡxQphDQtybq
987Please respect copyright.ＰＥＮＡＮＡgwwZpUeJOq
（圖5）另外，他們亦對愛德華·孟克那時期捐贈予館舍的顏料油作出檢測。987Please respect copyright.ＰＥＮＡＮＡ4cefg0dMVk
987Please respect copyright.ＰＥＮＡＮＡmaaLpfNdje
987Please respect copyright.ＰＥＮＡＮＡG5GL5RScPy
在畫紙塗上顏料油後，已能測量得到有一定程度份量的Wet Method副產物Cd(OH)Cl（左圖綠點）。987Please respect copyright.ＰＥＮＡＮＡt7obxmymgd
987Please respect copyright.ＰＥＮＡＮＡRQ2Ay0L2OB
（右圖）用上90 日相對濕度≥ 95%，攝氏為40°C的方式摧殘後，綠點數量大增且集中在一起。987Please respect copyright.ＰＥＮＡＮＡeYkYWPtngW
987Please respect copyright.ＰＥＮＡＮＡSrHNjHGjbh
987Please respect copyright.ＰＥＮＡＮＡDTIwJuPCcG
（圖6）換句話說，當時期以Wet Method製作的Cadmium sulfide顏料以及愛德華·孟克所使用的顏料油，乃是導致畫中黃色地方出現變白及有脫落跡象的元兇，而其變色的機制主要由相對濕度和溫度而非光線控制。987Please respect copyright.ＰＥＮＡＮＡKjyK0XX0bo
987Please respect copyright.ＰＥＮＡＮＡBdGxI28iCG
987Please respect copyright.ＰＥＮＡＮＡ755scMNbMT
基於這發現，在相對濕度及溫度嚴密的控制下，吶喊他日將來也許會有機會可以再度長期公開示人。987Please respect copyright.ＰＥＮＡＮＡlBx1Gq8s9n
987Please respect copyright.ＰＥＮＡＮＡeRJbcD6I9B
如果想我快啲出文的話，請入去Penana網站科普專欄–薯不揀單俾一個like以及Bookmark，這對我非常之重要。987Please respect copyright.ＰＥＮＡＮＡrfpaXczUpF
987Please respect copyright.ＰＥＮＡＮＡcdVDgnBqHT
Link: https://www.penana.com/story/66244/%E7%A7%91%E6%99%AE%E5%B0%88%E6%AC%84-%E8%96%AF%E4%B8%8D%E6%8F%80%E5%96%AE/toc987Please respect copyright.ＰＥＮＡＮＡcZ1h9nzzjA
987Please respect copyright.ＰＥＮＡＮＡROyjjGqso3
同時亦可以在Penana網站裡按「買一嚿/半嚿薯仔」，以課金的方式推動我繼續搜羅資料寫文，多謝。987Please respect copyright.ＰＥＮＡＮＡLGSu7L2jnj
987Please respect copyright.ＰＥＮＡＮＡHbBlNrl6l5
Link:987Please respect copyright.ＰＥＮＡＮＡRyQxUltrpk
https://www.penana.com/user/27349/%E8%96%AF%E4%BB%94%E8%81%9E%E8%8C%B1%E8%8E%89/portfolio987Please respect copyright.ＰＥＮＡＮＡ9k5PjjOonK
987Please respect copyright.ＰＥＮＡＮＡCMzJqpyFiq
987Please respect copyright.ＰＥＮＡＮＡGX9ywPOhqN
有興趣接收科學資訊的話，歡迎follow IG: potatopigtongue。987Please respect copyright.ＰＥＮＡＮＡamvaCV827f
987Please respect copyright.ＰＥＮＡＮＡupatvG31tT
Ref1:https://advances.sciencemag.org/content/6/20/eaay3514987Please respect copyright.ＰＥＮＡＮＡhxX2u5UGIe
8964 copyright protection983ＰＥＮＡＮＡp22AT9m5pJ 維尼

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