Patents by Inventor Yiwei Zhang

Yiwei Zhang has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20150035197
    Abstract: Processes for producing carbon fibre, the filament thereof and pre-oxidized fibre are provided. In one embodiment, the gel spinning of polyacrylonitrile filament is achieved by using small-molecule gelling agent, and the carbon fibre obtained thereby is increased by 15% to 40% in tensile strength and by 20% to 35% in toughness. In another embodiment, the melt spinning process of polyacrylonitrile is conducted by using imidazole type ion liquid as plasticizer, the process reduces environment pollution, is suitable for industrial production and the fibre produced thereby is improved in its strength. In yet another embodiment, polyacrylonitrile pre-oxidized fibre is produced by melt spinning, so low cost and controllable pre-oxidization of polyacrylonitrile can be achieved. In a further embodiment, high strength carbon fibre is manufactured by using polymer thickening agent.
    Type: Application
    Filed: October 20, 2014
    Publication date: February 5, 2015
    Inventors: Muhuo Yu, Huaiping Rong, Keqing Han, Zhaohua Wang, Yiwei Zhang, Yincai Tian, Qinli Dong
  • Patent number: 8947060
    Abstract: An embodiment of the invention relates to a power converter formed with an error amplifier and a related method. In an embodiment, a first switch is coupled in series with an error amplifier compensation capacitor. Upon detection of a current level greater than a threshold level, the compensation capacitor is decoupled from the error amplifier by opening the first switch. In an embodiment, a second switch is coupled in parallel with the compensation capacitor, and the current-sensing circuit enables conductivity of the second switch to discharge the compensation capacitor upon detection of the current level greater than the threshold level. The second switch is opened upon detection of the current level less than the threshold level. In an embodiment, the current-sensing circuit controls an output current of the power converter at a current-limit level upon detection of the internal current level greater than the threshold level.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: February 3, 2015
    Assignee: STMicroelectronics (Shenzhen) R&D Co., Ltd.
    Inventors: Da Song Lin, Ni Zeng, Gang Zha, Xianfeng Xiong, Yiwei Zhang
  • Patent number: 8906278
    Abstract: Processes for producing carbon fiber, the filament thereof and pre-oxidized fiber are provided. In one embodiment, the gel spinning of polyacrylonitrile filament is achieved by using small-molecule gelling agent, and the carbon fiber obtained thereby is increased by 15% to 40% in tensile strength and by 20% to 35% in toughness. In another embodiment, the melt spinning process of polyacrylonitrile is conducted by using imidazole type ion liquid as plasticizer, the process reduces environment pollution, is suitable for industrial production and the fiber produced thereby is improved in its strength. In yet another embodiment, polyacrylonitrile pre-oxidized fiber is produced by melt spinning, so low cost and controllable pre-oxidization of polyacrylonitrile can be achieved. In a further embodiment, high strength carbon fiber is manufactured by using polymer thickening agent.
    Type: Grant
    Filed: January 11, 2010
    Date of Patent: December 9, 2014
    Assignee: Donghua University
    Inventors: Muhuo Yu, Huaiping Rong, Keqing Han, Zhaohua Wang, Yiwei Zhang, Yincai Tian, Qinli Dong, Xi Zhao, Hui Zhang
  • Publication number: 20120027944
    Abstract: Processes for producing carbon fibre, the filament thereof and pre-oxidized fibre are provided. In one embodiment, the gel spinning of polyacrylonitrile filament is achieved by using small-molecule gelling agent, and the carbon fibre obtained thereby is increased by 15% to 40% in tensile strength and by 20% to 35% in toughness. In another embodiment, the melt spinning process of polyacrylonitrile is conducted by using imidazole type ion liquid as plasticizer, the process reduces environment pollution, is suitable for industrial production and the fibre produced thereby is improved in its strength. In yet another embodiment, polyacrylonitrile pre-oxidized fibre is produced by melt spinning, so low cost and controllable pre-oxidization of polyacrylonitrile can be achieved. In a further embodiment, high strength carbon fibre is manufactured by using polymer thickening agent.
    Type: Application
    Filed: January 11, 2010
    Publication date: February 2, 2012
    Inventors: Muhuo Yu, Huaiping Rong, Keqing Han, Zhaohua Wang, Yiwei Zhang, Yincai Tian, Qinli Dong, Xi Zhao, Hui Zhang
  • Publication number: 20110156688
    Abstract: An embodiment of the invention relates to a power converter formed with an error amplifier and a related method. In an embodiment, a first switch is coupled in series with an error amplifier compensation capacitor. Upon detection of a current level greater than a threshold level, the compensation capacitor is decoupled from the error amplifier by opening the first switch. In an embodiment, a second switch is coupled in parallel with the compensation capacitor, and the current-sensing circuit enables conductivity of the second switch to discharge the compensation capacitor upon detection of the current level greater than the threshold level. The second switch is opened upon detection of the current level less than the threshold level. In an embodiment, the current-sensing circuit controls an output current of the power converter at a current-limit level upon detection of the internal current level greater than the threshold level.
    Type: Application
    Filed: November 23, 2010
    Publication date: June 30, 2011
    Applicant: STMicroelectronics (Shenzhen) R&D Co. Ltd
    Inventors: Da Song Lin, Ni Zeng, Gang Zha, Xianfeng Xiong, Yiwei Zhang