Abstract: A method for preparing a high viscosity index poly-?-olefin subjects ?-olefin to a polymerization reaction in the presence of a metallocene catalyst to obtain a poly-?-olefin. The polymerization reaction is carried out in the absence of a solvent, and the metallocene catalyst is formed of, or is formed by interaction between, a metallocene compound and an activator.

Abstract: A reactor system configured to use valve pulsing to control precursor pressure as part of substrate or other processing. A controller in the reactor system runs a pressure control module to process pressure signals from a pressure sensor sensing pressure within an accumulator disposed between a reaction chamber and a precursor source vessel. Based on a pressure set point for the accumulator and the sensed pressure feedback, the controller generates valve control or valve pulsing signals to operate one or more fill valves used to control fill of the accumulator with gas (e.g., precursor) from the precursor source vessel. The fill valves may be high-speed diaphragm valves configured for operation in high temperature applications to be fully opened or fully closed, and the control signals cause the valves to rapidly pulse open and closed to adjust the pressure within the accumulator.

Abstract: Methods and apparatuses for measuring a flow conductance of a showerhead assembly are described. For example, a showerhead assembly may be seated in a housing. A gas source may be coupled to an intake port of the showerhead assembly and supply gas to the showerhead assembly via the intake port. A pressure controller may be coupled between the gas source and the showerhead assembly. The pressure controller may measure a flow throughput of the gas that passes through the pressure controller. The pressure controller may maintain the gas being supplied to the showerhead assembly at a first pressure value. A pressure transducer coupled to an exhaust port of the showerhead assembly may measure a second pressure value. A controller may determine a flow conductance of the showerhead assembly based on the flow throughput and the first and second pressure values.

Abstract: A method for preparing a high viscosity index poly-?-olefin subjects ?-olefin to a polymerization reaction in the presence of a metallocene catalyst to obtain a poly-?-olefin. The polymerization reaction is carried out in the absence of a solvent, and the metallocene catalyst is formed of, or is formed by interaction between, a metallocene compound and an activator.

Abstract: A metallocene compound having a structure shown by formula (I). A functional group connected to a bridging atom of the metallocene compound is an amine-substituted group and/or a metallocene-substituted group and/or a substituted metallocene group. A metallocene catalyst containing the metallocene compound has high catalytic activity, and can synthesize metallocene polypropylene having high isotacticity.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for grouping a plurality of resources into a plurality of cohorts, wherein each of the plurality of resources is associated with a risk level and a benefit level, and resources in each cohort share the same risk level and the same benefit level; obtaining a plurality of provider-level adjustments; constructing an optimization model for determining a resource flow solution; and according to the plurality of cohort-provider-level adjustments, identifying one or more resources in each of the plurality of cohorts that are provided by a first provider to be transferred to a second provider; and automatically sending one or more requests to the first provider and the second provider to transfer the determined one or more first resources from the first provider to the second provider.

Abstract: The present invention relates to an n-heterocyclic carbene (NHC) type palladium catalyst and its preparation method as well as applications. Its preparation process is as below: select glyoxal as the raw material to synthesize glyoxaldiimine in the presence of Lewis acid or Bronsted acid, and then react with paraformaldehyde to get the NHC type ligand. Use palladium(II) to react with the compound containing carbon-nitrogen double bonds to get palladium(II) cyclic dimer; make the palladium cyclic dimer and the NHC type ligand coordinated to get the NHC type palladium catalyst. The palladium catalyst with a brand new structure according to the present invention, boasts high activity and multi-purpose.

Abstract: The present invention relates to an n-heterocyclic carbene (NHC) type palladium catalyst and its preparation method as well as applications. Its preparation process is as below: select glyoxal as the raw material to synthesize glyoxaldiimine in the presence of Lewis acid or Bronsted acid, and then react with paraformaldehyde to get the NHC type ligand. Use palladium(II) to react with the compound containing carbon-nitrogen double bonds to get palladium(II) cyclic dimer; make the palladium cyclic dimer and the NHC type ligand coordinated to get the NHC type palladium catalyst. The palladium catalyst with a brand new structure according to the present invention, boasts high activity and multi-purpose.