Abstract: Provided is a method of preparing a phosphonium compound by reacting a protic phosphonium compound represented by [(R1)—P(R2)a(R2?)b]HX and a salt compound represented by [C][Ani]. Therefore, a phosphonium compound used as a cocatalyst for the preparation of a polar cyclic olefin polymer can be produced at high yield.

Abstract: Provided are a bimetallic zinc complex and a method of producing polycarbonate, including polymerizing an epoxy compound and carbon dioxide using the bimetallic zinc complex. The bimetallic zinc complex according to the present invention has a distance between zinc-zinc atoms, which is maintained in a limited range regardless of its concentration in a reaction medium for the polymerization. Thus, the bimetallic zinc complex can have a polymerization activity even at a high ratio of monomer/catalyst, thereby reducing a catalyst amount to be used, which is economically advantageous. Further, the bimetallic zinc complex can produce a high molecular weight polycarbonate.

Abstract: Provided are a bridged metallocene compound particularly suitable for copolymerization of ethylene and alpha-olefin or cyclic olefin, a process of preparing the metallocene compound, and a process of preparing polyolefin using the metallocene compound. The bridged metallocene compound has low steric hindrance and good (co)polymerization activity, and thus, exhibits good activity in copolymerization of ethylene and alpha-olefin such as 1-hexene or 1-octene. Furthermore, the process of preparing the bridged metallocene compound is simplified, and thus, suitable for mass production.

Abstract: A catalyst system capable of producing a cyclic olefin polymer having a polar functional group and a high molecular weight with a high yield in which a catalyst is not deactivated due to polar functional groups of monomers, and a method of producing polymers using the same are provided. The catalyst system for polymerization of olefin according to the present invention has good thermal and chemical stability, and thus, in the method of preparing polyolefin using the catalyst system, the deactivation of a catalyst due to a polar functional group of the monomer can be prevented, and thus a high yield of the cyclic olefin polymer with a high molecular weight can be obtained when a ratio of the catalyst to the monomer is 1:5000, and the removal of a catalyst residue is not required.

Abstract: Disclosed is a fixing rail of a terminal block capable of easily assembling various electric/electronic components. Electric/electronic devices and so forth in a control box, and facilitating the maintenance thereof, as well as the easy movement thereof. The fixing rail of a terminal block includes wings (12) extended from both sides of a C-shaped body (10), with a plurality of bodies arranged in a row, the respective bodies (10) provided at a center thereof with a hole (14), and a plurality of holes (14) formed at the bodies being spaced apart from each other at regular intervals. The fixing rail comprises a cutting groove (2) formed between the bodies, the cutting groove (2) provided at upper and lower portions of the body (10); and a gap (1) formed between ends of the wings (12), such that the fixing rail may be cut by a desired length using a hand or nipper, without using a cutter or a saw.

Abstract: The invention relates to a landfill structure and a method for operating the same and, more particularly, to a landfill structure using a concept of multi-layered reactors, a method for making efficient use of landfill gas generated from the landfill, a method for early stabilizing the landfill and a method for reducing environmental contaminants generated from the landfill.

Abstract: There are provided a method of simply preparing a 1,4,6-substituted, 1,4-substituted, 1,6-substituted, or 1-substituted fulvene compound, the intermediates of the fulvene compound, and a method of preparing an ansa-metallocene compound in which two cyclopentadienyl ligands are bridged by one carbon and there are substituents only at positions adjacent to the bridging point of a cyclopentadienyl ligand, using the fulvene compound.