【摘要】 铅白（2PbCO₃·Pb（OH）₂）、铅丹（Pb₃O₄）、密陀僧（PbO）是我国古代制造的三种铅的化合物.历代彩绘艺术品中大都作为绘画颜料应用.在长久的自然环境中,这三种铅颜料都会逐渐变黑.根据对敦煌莫高窟北凉、北魏、西魏、北周、隋、唐、五代、宋、西夏、元等十个朝代洞窟颜料的X射线衍射和X射线荧光分析可知:历代壁画、彩塑中变成棕褐色的颜料全部是二氧化铅（PbO₂）.通过对铅颜料化学反应原理的探讨、铅颜料变色的模拟实验等棕合研究,初步认为:紫外线、H₂S气体、相对湿度等是影响铅颜料变色的主要因素.而紫外线对铅颜料变色影响最大.在高于60%相对湿度时,密陀僧会引起变色和颜料薄层的粉状化,在80%相对湿度时特别严重.铅丹在相对湿度为80%时,表面变色严重.由于敦煌彩绘艺术中没有分析出硫化铅（PbS）颜料,由此证明,敦煌石窟受H₂S气体的影响很小.更多还原

【Abstract】 Lead white（2 PbC0₃·Pb（OH）₃）Red lead（Pb₃ O₄） and litharge（PbO）are there kinds of chemical comound evented by ancient Chinese.They are used as painting colours on painted works of art through the ages.Being exposed in natural environment for a long time.All of them will be getting black.It is known that the browned colours on the surface of murals and on modelling of past dynasties are all materials of PbO₂ by doing X-ray diffraction and X-ray spectrum meter to the grottoes dated in Northern Liang,Northern Wei,Western Wei,Northern Zhou,Sui,Tang,Five Dynasties,Song,West Xi xia and Yuan,in Mogao Grottoes.After going further into the principles of chemical reaction of colours of lead and doing simulated experiment of colour changes of lead, etc it is thought preliminarily that ultraviolet ray,gas of H₂ S and relative humidity are three main factors influencing colour changes of lead,especially ultraviolet-ray.If the RH is.above 60%,it will evoke colour changes and make the surface of colours powdery especially in 80% above RH; colour changes of surface of Pb₃ O₄ will be most serious when its RH is 80%.There is not colours from PbS,so it is conclused that influence of H₂ S to Mogao Grottoes is quite weak.更多还原