Abstract: A projection lens, a projection device and an optically-induced microparticle device are provided. The projection lens includes an aperture, a first and a second lens groups. The aperture, the first and the second lens groups are disposed on a projection path of an image. The aperture is between the first and the second lens groups. The first and the second lens groups are suitable for interchanging with each other to switch the magnification ratio. When in a first state, the first lens group is between the object and the aperture and the second lens group is between the aperture and a projection surface, herein the projection lens has a first magnification ratio. When in a second state, the first lens group is between the aperture and the projection surface, and the second lens group is between the object and the aperture, herein the projection lens has a second magnification ratio.

Abstract: A transaction card system includes a transaction cared with a display tag for displaying short term information, the character display having optical states that are stable without power and viewable from one side of the display tag and an array of electrical contacts for electrically addressing the character display from the other side of the tag, a contact window through which the contacts are accessible, machine readable data on the card, and long term information printed on the transaction card; a transaction card writer having a reader for reading the machine readable data and having means for updating the short term information displayed on the transaction card; and a central computer connected to the transaction card writer having a data base and a central processor for receiving the information read by the magnetic card reader and generating display commands for the transaction card writer.

Abstract: A high viscosity liquid is fed into a rotation pack bed at a position with a distance far enough from a rotation axis, creating a centrifugal force exerted on the high viscosity liquid overwhelming a drag thereof, so that it can flow radially through the rotation pack bed. A high pressure gas is introduced into the rotation pack bed peripherally and/or a suction force source is connected to a position near the rotation axis, so that a volatile component contained in the high viscosity fluid is entrained in the gas counter currently flowing through the rotation pack bed and withdrawn from the position near the rotation axis, or the volatile component exits from the position near the rotation axis in gas phase, and thus the volatile component is removed from the high viscosity liquid. A second fluid can also be fed into the rotation pack bed to react with the high viscosity liquid, so that a reaction product is formed, and a volatile side product is removed at the same time.