Abstract: Provided are a nonmetal corrosion-resistant heat exchange device (20) and a plate-type heat exchanger (100) having same. The heat exchange device (20) comprises a plurality of nonmetal corrosion-resistant heat exchange sheets (21), upper support ribs (22) and lower support ribs (23) installed on top and bottom surfaces of each heat exchange sheet (21), sealing strips (25) disposed at the upper and lower edges at each side of the heat exchange sheets (21), and spacers (26). The adjacent upper support ribs (22) and the lower support ribs (23) located between the adjacent heat exchange sheets (21) together define multiple sealing channels for cold fluid and hot fluid. The spacers (26) completely seal the upper support ribs (22), the lower support ribs (23) and the sealing strips (25) via a press force.

Abstract: The present invention discloses a process for stereoselective synthesis of Lamivudine comprising the following steps: (a) performing a glycosylation reaction between the compound of formula (I) and cytosine or protected cytosine, and separating the reaction product by recrystallization to obtain the intermediate of formula (II); and (b) deprotecting the intermediate of formula (II) to obtain Lamivudine.

Abstract: The present invention discloses a process for stereoselective synthesis of Lamivudine comprising the following steps: (a) performing a glycosylation-reaction between the compound of formula (I) and cytosine or protected cytosine, and separating the reaction product by recrystallization to obtain the intermediate of formula (II); and (b) deprotecting the intermediate of formula (II) to obtain Lamivudine.

Abstract: The present invention discloses a process for stereoselective synthesis of Lamivudine comprising the following steps: (a) performing a glycosylation-reaction between the compound of formula (I) and cytosine or protected cytosine, and separating the reaction product by recrystallization to obtain the intermediate of formula (II); and (b) deprotecting the intermediate of formula (II) to obtain Lamivudine.

Abstract: A process for stereoselective synthesis of lamivudine, comprising (a) glycosylation of compounds of formula (I) and cytosine or protected cytosine, separating the resulting products by crystallization to afford intermediates of formula (II); (b) removing the protecting groups of intermediates of formula (II) to obtain lamivudine.

Abstract: Methods and systems for encoding and decoding a 2D symbol is disclosed. According to one aspect of the 2D symbol, the following characteristics are realized: 1) variable symbol widths and height; 2) variable print resolution, 3) multiple damage protection levels; 4) large information storage; 5) high redundancy; 6) readable by line based scanning devices; 7) recognizable by either contact scanning or non-contact scanning devices. In addition, a set of positioning lines are attached 2D symbol for guiding scanning devices to decode the 2D symbol with proper resolution.

Abstract: To facilitate the decoding of a 2D symbol (e.g., PDF417), a plurality of positioning lines are attached to the 2D symbol. Depending on implementation, these substantially parallel positioning lines may be provided on at least one side of the symbol or superimposed on the symbol. A scanning device is provided to capture an image of the symbol together with these positioning lines that are then detected to determine an orientation of the 2D symbol. In some cases, these positioning lines are used to correct images with distortion.

Abstract: Methods and systems for encoding and decoding a 2D symbol is disclosed. According to one aspect of the 2D symbol, the following characteristics are realized: 1) variable symbol widths and height; 2) variable print resolution, 3) multiple damage protection levels; 4) large information storage; 5) high redundancy; 6) readable by line based scanning devices; 7) recognizable by either contact scanning or non-contact scanning devices. In addition, a set of positioning lines are attached 2D symbol for guiding scanning devices to decode the 2D symbol with proper resolution.

Abstract: To facilitate the decoding of a 2D symbol (e.g., PDF417), a plurality of positioning lines are attached to the 2D symbol. Depending on implementation, these substantially parallel positioning lines may be provided on at least one side of the symbol or superimposed on the symbol. A scanning device is provided to capture an image of the symbol together with these positioning lines that are then detected to determine an orientation of the 2D symbol. In some cases, these positioning lines are used to correct images with distortion.