Is the library allowed to make a copy of a work and save it in the archive (for preservation)?

Yes, libraries can 'preserve' scientific resources under certain conditions.

Article 16n of the act accurately specifies the restrictions for making a 'preservation copy'. A preservation copy can only be used to restore a copy, to prevent a copy of the work from expiring or to keep a copy of the work accessible if the technology becomes unusable. Information previously stored on floppy disks, for example, can now be stored on CD-ROM or other storage media. The library must also have obtained its original copy lawfully (i.e. not illegally). However, arrangements must be made with the copyright holders regarding the provision of the preservation copy to users. According to the law, this is absolutely reasonable in order to protect of their interests.