摘要:
The invention provides ethylene/α-olefin copolymers exhibiting improved environmental stress cracking resistance properties, and methods for the production of the copolymers in a single reactor by means of a bimetallic catalyst including a Ziegler component and a metallocene component.
摘要:
The invention provides ethylene/α-olefin copolymers exhibiting improved environmental stress cracking resistance properties, and methods for the production of the copolymers in a single reactor by means of a bimetallic catalyst including a Ziegler component and a metallocene component.
摘要:
Bimetallic catalyst for producing polyethylene resins with a bimodal molecular weight distribution, its preparation and use. The catalyst is obtainable by a process which includes contacting a support material with an organomagnesium component and carbonyl-containing component. The support material so treated is contacted with a non-metallocene transition metal component to obtain a catalyst intermediate, the latter being contacted with an aluminoxane component and a metallocene component, This catalyst may be further activated with, e.g., alkylaluminum cocatalyst, and contacted, under polymerization conditions, with ethylene and optionally one or more comonomers, to produce ethylene homo- or copolymers with a bimodal molecular weight distribution and improved resin swell properties in a single reactor. These ethylene polymers are particularly suitable for blow molding applications.
摘要:
A non-volatile memory cell having a split gate, wherein the floating gate and the coupling/control gate have complimentary non-planar shapes. The shape may be a step shape. An array of such cells and a method of manufacturing the cells are also disclosed.
摘要:
A non-volatile memory cell has a single crystalline substrate of a first conductivity type with a top surface. A first region of a second conductivity type is in the substrate along the top surface. A second region of the second conductivity type is in the substrate along the top surface, spaced apart from the first region. A channel region is the first region and the second region. A word line gate is positioned over a first portion of the channel region, immediately adjacent to the first region. The word line gate is spaced apart from the channel region by a first insulating layer. A floating gate is positioned over another portion of the channel region. The floating gate has a lower surface separated from the channel region by a second insulating layer, and an upper surface opposite the lower surface. The floating gate has a first side wall adjacent to but separated from the word line gate; and a second side wall opposite the first side wall. The second side wall and the upper surface form a sharp edge, with the second side wall greater in length than the first side wall. The upper surface slopes upward from the first side wall to the second side wall. A coupling gate is positioned over the upper surface of the floating gate and is insulated therefrom by a third insulating layer. An erase gate is positioned adjacent to the second side wall of the floating gate. The erase gate is positioned over the second region and insulated therefrom.
摘要:
Bimetallic catalyst for producing polyethylene resins with a bimodal molecular weight distribution, its preparation and use. The catalyst is obtainable by a process which includes contacting a support material with an organomagnesium component and carbonyl-containing component. The support material so treated is contacted with a non-metallocene transition metal component to obtain a catalyst intermediate, the latter being contacted with an aluminoxane component and a metallocene component. This catalyst may be further activated with, e.g., alkylaluminum cocatalyst, and contacted, under polymerization conditions, with ethylene and optionally one or more comonomers, to produce ethylene homo- or copolymers with a bimodal molecular weight distribution and improved resin swell properties in a single reactor. These ethylene polymers are particularly suitable for blow molding applications.
摘要:
The present invention is directed to processes of polymerization of olefins and copolymerization of olefins and functionalized olefins in the presence of certain late transition metal bidentate salicylaldimine chelates represented by the formula: wherein each of the symbols R, R1, R2, R3, R4, R5, R6, L, M, A, X and z are defined within the specification herein below.
摘要:
Substantially linear vinylene carbonate/1-olefin copolymers, a process of forming the same, and packaging materials incorporating the same are described. These copolymers are formed by reacting the component monomers in the presence of a single component, non-ionic polymerization catalyst at relatively low temperatures and pressures.
摘要:
A method for preparing semiconductor nanocrystals comprises reacting cation precursors and anion precursors in a reaction mixture including one or more acids, one or more phenol compounds, and a solvent to produce semiconductor nanocrystals having a predetermined composition. A method for forming a coating on at least a portion of a population of semiconductor nanocrystals is also disclosed. The method comprises forming a first mixture including a population of semiconductor nanocrystals, one or more amine compounds, and a first solvent; adding cation precursors and anion precursors to the first mixture at a temperature sufficient for growing a semiconductor material on at least a portion of an outer surface of at least a portion of the population of semiconductor nanocrystals; and initiating addition of one or more acids to the first mixture after addition of the cation and anion precursors is initiated. Semiconductor nanocrystals and populations thereof are also disclosed.
摘要:
A method for preparing semiconductor nanocrystals is disclosed. The method includes adding one or more cation precursors and one or more anion precursors in a reaction mixture including a solvent in a reaction vessel, maintaining the reaction mixture at a first temperature and for a first time period sufficient to produce semiconductor nanocrystal seed particles of the cation and the anion, and maintaining the reaction mixture at a second temperature that is higher than the first temperature for a second time period sufficient to enlarge the semiconductor nanocrystal seed particles to produce semiconductor nanocrystals from the cation and the anion.