In this paper,a design of ultraphonic tubulous water communication system based on OFDM is introduced. The system takes PL3106 which is embedded enhanced 8051 microprocessor as the control chip and takes TMS320VC5509 ...In this paper,a design of ultraphonic tubulous water communication system based on OFDM is introduced. The system takes PL3106 which is embedded enhanced 8051 microprocessor as the control chip and takes TMS320VC5509 as the core of OFDM modulation-demodulation.In the paper,the principle of OFDM is introduced briefly.The hardware and software of the system are designed and the experimental results are analysed and concluded.展开更多
The organic structure-directing agent(OSDA)-free synthesis of MCM-49 is strongly desired because OSDA makes synthesis cost expensive and environment unfriendly.In this work,an efficient,eco-friendly and simple route t...The organic structure-directing agent(OSDA)-free synthesis of MCM-49 is strongly desired because OSDA makes synthesis cost expensive and environment unfriendly.In this work,an efficient,eco-friendly and simple route to synthesize MCM-49 zeolite is developed,via seed-assistance,without deliberately adding OSDA,with ultraphonic aging treatment.For comparison,the effect of microwave aging,mechanical stirring aging and without any aging processes on the synthesis is investigated.Due to the acoustic cavitation,the ultraphonic aging treatment shows superiority over the others.Ultraphonic aging not only keeps the MCM-49 seed integrity but also promotes both the silica species and aluminum species to the solid phase,which is beneficial for the growth of MCM-49 and the suppression of MOR formation in the absence of OSDA.^(27)Al MAS NMR data show that the seed-assisted MCM-49 almost has no extra-framework aluminum,but dealumination will happen upon ammonium exchange.^(23)Na MAS NMR results demonstrate that the interaction between Na ions and framework of the seed-assisted MWW product is strengthened after calcination,which makes the exchange of Na species difficult.Alternatively,ammonium exchange upon the as-made sample is an effective method to remove Na species,which improves the micropore volume,external surface area,and acid amount of the seed-assisted MCM-49.展开更多
文摘In this paper,a design of ultraphonic tubulous water communication system based on OFDM is introduced. The system takes PL3106 which is embedded enhanced 8051 microprocessor as the control chip and takes TMS320VC5509 as the core of OFDM modulation-demodulation.In the paper,the principle of OFDM is introduced briefly.The hardware and software of the system are designed and the experimental results are analysed and concluded.
基金supported by the National Natural Science Foundation of China(U20A20120)Dalian Science and Technology Innovation Fund Project(2019J12GX027)+2 种基金LiaoNing Revitalization Talents Program(XLYC1901006 and XLYC1908010)Dalian Engineering Research Center for Key Aromatic CompoundsSTS Network Initiative of the CAS(KFJ-STS-QYZD-2021-17-001).
文摘The organic structure-directing agent(OSDA)-free synthesis of MCM-49 is strongly desired because OSDA makes synthesis cost expensive and environment unfriendly.In this work,an efficient,eco-friendly and simple route to synthesize MCM-49 zeolite is developed,via seed-assistance,without deliberately adding OSDA,with ultraphonic aging treatment.For comparison,the effect of microwave aging,mechanical stirring aging and without any aging processes on the synthesis is investigated.Due to the acoustic cavitation,the ultraphonic aging treatment shows superiority over the others.Ultraphonic aging not only keeps the MCM-49 seed integrity but also promotes both the silica species and aluminum species to the solid phase,which is beneficial for the growth of MCM-49 and the suppression of MOR formation in the absence of OSDA.^(27)Al MAS NMR data show that the seed-assisted MCM-49 almost has no extra-framework aluminum,but dealumination will happen upon ammonium exchange.^(23)Na MAS NMR results demonstrate that the interaction between Na ions and framework of the seed-assisted MWW product is strengthened after calcination,which makes the exchange of Na species difficult.Alternatively,ammonium exchange upon the as-made sample is an effective method to remove Na species,which improves the micropore volume,external surface area,and acid amount of the seed-assisted MCM-49.
