X-Ray Crystallography Facilityx -射线结晶照相设备 Xenos Christian FellowshipXenos基督徒团契 eXperimental Computing Facility (graphics software for Irix SGI; file extension)实验计算设备(图形软件Irix SGI;文件扩展名) Cross-System Coupling FacilityCross-System耦合装置 eXperimental Computing Facility实验计算设备