Pd-catalyzed carbonylation,as an efficient synthetic approach to the installation of carbonyl groups in organic compounds,has been one of the most important research fields in the past decade.Although elegant reaction...Pd-catalyzed carbonylation,as an efficient synthetic approach to the installation of carbonyl groups in organic compounds,has been one of the most important research fields in the past decade.Although elegant reactions that allow highly selective carbonylations have been developed,straightforward routes with improved reaction activity and broader substrate scope remain long-term challenges for new practical applications.Here,we show a new type of synergistic Cu/Pd-catalyzed carbonylation reaction using alcohols and dioxgen as the carbonyl sources.A broad range of aryl iodides and alcohols are compatible with this protocol.The reaction is concise and practical due to the ready availability of the starting materials and the scalability of the reaction.In addition,the reaction affords lactones and lactams in an intermolecular fashion.Moreover,DFT calculations have been performed to study the detailed mechanisms.展开更多
Using a relay feedback approach,mathematical expressions for identification of real-time level control system in transfer function form are proposed in this paper.An ideal relay with hysteresis is feedback to a simple...Using a relay feedback approach,mathematical expressions for identification of real-time level control system in transfer function form are proposed in this paper.An ideal relay with hysteresis is feedback to a simple level control system for the generation of sustained oscillations.Subsequently,limit cycle information is utilised in deduced expressions for the estimation of unknown system parameters.Using describing function analysis,the gain of an ideal relay with hysteresis is approximated to yield simple mathematical expressions.Typical examples from literature are considered to show the effectiveness of the proposed identification scheme.Yokogawa distributed control system:CENTUM CS 3000 is considered as a platform for the realisation of both relay feedback and Ziegler-Nichols(ZN)method.The accuracy of derived transfer function models is compared with a model derived from ZN method and thereafter demonstrated through frequency response plots which illustrate the experimental validation of the identified real-time process model.展开更多
基金supported by the Science Foundation for Distinguished Young Scholars for Guangdong Province(2020B1515020026)the Science and Technology Program of Guangzhou(202103000089)+6 种基金the Innovation Team Project of Universities in Guangdong Province(2020KCXTD009)the Scientific Research Projects for Key Disciplines of Guangdong Province(2019-GDXK-0009)the Key Projects of Social Welfare and Basic Research of Zhongshan City(2020B2007)the Innovation and Strong School Project of Guangdong Pharmaceutical University(2018KQNCX131)Guangdong Cosmetics Engineering&Technology Research CenterProvincial Experimental Teaching Demonstration Center of Chemistry&Chemical EngineeringSpecial Funds of Key Disciplines Construction from Guangdong and Zhongshan Cooperating。
文摘Pd-catalyzed carbonylation,as an efficient synthetic approach to the installation of carbonyl groups in organic compounds,has been one of the most important research fields in the past decade.Although elegant reactions that allow highly selective carbonylations have been developed,straightforward routes with improved reaction activity and broader substrate scope remain long-term challenges for new practical applications.Here,we show a new type of synergistic Cu/Pd-catalyzed carbonylation reaction using alcohols and dioxgen as the carbonyl sources.A broad range of aryl iodides and alcohols are compatible with this protocol.The reaction is concise and practical due to the ready availability of the starting materials and the scalability of the reaction.In addition,the reaction affords lactones and lactams in an intermolecular fashion.Moreover,DFT calculations have been performed to study the detailed mechanisms.
文摘Using a relay feedback approach,mathematical expressions for identification of real-time level control system in transfer function form are proposed in this paper.An ideal relay with hysteresis is feedback to a simple level control system for the generation of sustained oscillations.Subsequently,limit cycle information is utilised in deduced expressions for the estimation of unknown system parameters.Using describing function analysis,the gain of an ideal relay with hysteresis is approximated to yield simple mathematical expressions.Typical examples from literature are considered to show the effectiveness of the proposed identification scheme.Yokogawa distributed control system:CENTUM CS 3000 is considered as a platform for the realisation of both relay feedback and Ziegler-Nichols(ZN)method.The accuracy of derived transfer function models is compared with a model derived from ZN method and thereafter demonstrated through frequency response plots which illustrate the experimental validation of the identified real-time process model.
