DECLARE @name VARCHAR(50)   
DECLARE @path VARCHAR(256)  
DECLARE @fileName VARCHAR(256)    
DECLARE @fileDate VARCHAR(20)  

SET @path = 'F:\Database_Backup\'   

SELECT @fileDate = CONVERT(VARCHAR(20),GETDATE(),112)  
   + '_'  
   + REPLACE(CONVERT(VARCHAR(20),GETDATE(),108),':','') 

DECLARE db_cursor CURSOR FOR   
SELECT name  
FROM master.dbo.sysdatabases  
WHERE name NOT IN ('master','model','msdb','tempdb','ReportServer','ReportServerTempDB')  
   AND DATABASEPROPERTYEX(name, 'Recovery') IN ('FULL','BULK_LOGGED') 

OPEN db_cursor    
FETCH NEXT FROM db_cursor INTO @name    

WHILE @@FETCH_STATUS = 0    
BEGIN    
       SET @fileName = @path + @name + '_' + @fileDate + '.TRN'   
       BACKUP LOG @name TO DISK = @fileName   

       FETCH NEXT FROM db_cursor INTO @name    
END    

CLOSE db_cursor    
DEALLOCATE db_cursor