Invited for this month's cover is the group of Prof. Eike G. Hübner at Fraunhofer Heinrich Hertz Institute HHI, Goslar and Clausthal University of Technology, Clausthal-Zellerfeld, Germany. The cover picture shows a titanium plate, on which the crystal structure (golden circle=Ti, blue circle=O/N/C) of isomorphous TiO, TiN or TiC, respectively, has been engraved by a high-power high pulse repetition rate femtosecond laser process. The process allows for a fast and spatially resolved surface transformation of titanium to golden TiN, blue TiO/TiO₂ or black TiC in an atmosphere of nitrogen, air or ethene/argon. The background represents a typical surface microstructure of these interstitial compounds obtained during this transformation. Read the full text of the article at 10.1002/cplu.202100118.

中文翻译：

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通过高功率飞秒激光处理形成氮化钛、碳化钛和碳化硅表面

受邀参加本月封面的是位于德国克劳斯塔尔-采勒费尔德的弗劳恩霍夫海因里希赫兹研究所 HHI、戈斯拉尔和克劳斯塔尔理工大学的 Eike G. Hübner 教授小组。封面图为一块钛板，上面分别用高功率高脉冲重复率雕刻了同晶TiO、TiN或TiC的晶体结构（金圈=Ti，蓝圈=O/N/C）飞秒激光工艺。该过程允许钛在氮气、空气或乙烯/氩气气氛中快速和空间分辨的表面转变为金色 TiN、蓝色 TiO/TiO ₂或黑色 TiC。背景代表在这种转变过程中获得的这些填隙化合物的典型表面微观结构。在 10.1002/cpu.202100118 阅读文章全文。