Abstract: Disclosed herein are a mask for forming a landing plug contact hole to vertically expose an active region of a semiconductor substrate to a bit line or storage node contact, and a plug forming method using the same. Through the use of the crescent-shaped masks, it is possible to increase the critical dimension at a lower end of the resultant contact hole in contact with an active region of a semiconductor substrate, thereby enabling exposure of a wider area of the active region to be connected with the bit line or storage node contact.

Abstract: The present invention relates to a method for preparing optically active (R)-aryloxypropionic acid ester derivatives, and more particularly to a method for preparing (R)-aryloxypropionic acid ester derivatives with high optical purity and good yield at low cost from phenol derivatives with various substituted functional groups and (S)-alkyl O-arylsulfonyl lactates.

Abstract: Disclosed is a hat with a shade panel that is constructed in a simple manner, is convenient to use, is made at a substantially low cost, and has the shade panel placed at a substantially close distance to wearer's eyes to allow him to clearly view surrounding objects. The shade panel is adapted to be mounted on an inner periphery of a rim of the hat that comes in contact with a wearer's forehead, in such a manner as to be foldable by means of folding means.

Abstract: The present invention relates to optically active herbicidal (R)-phenoxypropionic acid N-methyl-N-2-fluorophenyl amide compounds represented in the following formula (1), a method for preparing thereof, their use to prevent generation of barnyard grass produced from rice and composition as suitable herbicides, (I) wherein X is hydrogen, halogen, hydroxy, NH2, CO2H, C1-C6 alkylamino substituted with 1 or 2 of C1-C3 alkyl, C1-C6 alkyl, C1-C6 alkoxy, C1-C3 haloalkyl, C1-C3 haloalkoxy, C2-C4 alkoxyalkoxy, C1-C4 alkylthonyl, C1-C4 alkylsulfonyl, C2-C6 alkenyl, C2-C6 alkinyl, C2-C6 alkenyloxy, C2-C6 alkinyloxy, C1-C3 alkoxycarbonyl, or C1-C3 alkylcarbonyl; is hydrogen or fluoro; and n is an integer of 0 to 2, wherein X can be a combination of other substituents when n is 2.