Electromagnetic interference(EMI)shielding materials with ultrathin,flexible,superior mechanical and thermal management properties are highly desirable for smart and wearable electronics.Here,ultrathin and flexible Ni...Electromagnetic interference(EMI)shielding materials with ultrathin,flexible,superior mechanical and thermal management properties are highly desirable for smart and wearable electronics.Here,ultrathin and flexible Ni/Cu/metallic glass/Cu/Ni(Ni/Cu/MG)multilayer composite with alternate magnetic and electrical structures was designed via facial electroless plating of Cu and Ni on an Fe-based metallic glass.The resultant 0.02 mm-thick Ni/Cu/MG composite displays a superior EMI shielding effectiveness(EMI SE)of 35 dB and a great EMI SE/t of 1750 dB/mm,which is greater than those of composites with monotonous multilayer or homogeneous structures.The improved EMI SE originates from the massive ohmic losses,the enhanced internal reflection/absorption,and the abundant interfacial polarization loss.Particularly,Ni/Cu/MG exhibits a high tensile strength of up to 1.2 GPa and outstanding mechanical stability,enabling the EMI SE remains unchanged after 10,000 times of bending.Moreover,Ni/Cu/MG has excellent Joule heating characteristics and thermal stability,which is very suitable for heating components of wearable hyperthermia devices.展开更多
Three alternating conjugated polymers,namely PFTP,PCz TP,and PSi TP,which combine a thieno[3,4-b]pyrazine(TP)unit with different benzene-based donor units such as 9,9-dioctylfluorene,9-heptadecyl-9H-carbazole and 5,5-...Three alternating conjugated polymers,namely PFTP,PCz TP,and PSi TP,which combine a thieno[3,4-b]pyrazine(TP)unit with different benzene-based donor units such as 9,9-dioctylfluorene,9-heptadecyl-9H-carbazole and 5,5-dioctyl-5H-dibenzo[b,d]silole,were synthesized in good yield(>85%)and high molecular weight up to Mn=5.82×10^(4) via direct arylation polymerization(DAr P).All the resultant polymers exhibit moderate bandgap of about 1.80 e V and strong deep red/near-infrared emitting in the solid state.Among them,the PSi TP-based electroluminescence(EL)devices with an architecture of ITO/PEDOT:PSS/PTAA/emitting layer/TPBi/Li F/Al give the best performance with a maximum luminance of 2543 cd/m^(2) at 478 m A/cm^(2).This work expands the application scope of high-performance conjugated polymers which can be synthesized by DAr P.展开更多
MXene-based multilayered composite films show great promise in electromagnetic interference(EMI)shielding field,but the trade-off between mechanical properties,oxidation resistance and EMI shielding performance remain...MXene-based multilayered composite films show great promise in electromagnetic interference(EMI)shielding field,but the trade-off between mechanical properties,oxidation resistance and EMI shielding performance remains a huge challenge.Herein,inspired by the architecture of millefeuille,alternating multilayered MXene/carbon nanotube(CNT)films were successfully prepared using an alternating vacuum-assisted filtration method,in which the alternating CNT layers not only act as the mechanical frame and oxidation barrier,but also synergistically enhance the EMI shielding effect of MXene layers through the distinctive“absorption-reflection-reabsorption”mechanism.By optimizing the alternating multilayered structure,the MXene/CNT film with a thickness of 36µm can achieve a remarkable EMI shielding effectiveness(SE)of 81.4 dB across the frequency range of 8.2–26.5 GHz.Meanwhile,the mechanical strength and toughness of the MXene/CNT film reach 83.4 MPa and 7.20 MJ/m^(3),respectively.Moreover,the CNT layer can effectively isolate MXene layer from oxygen,thus enabling the fire/oxidation resistance of the multilayer film in complex environments.Besides,the multilayered composite film exhibits impressive Joule heating capacity,which can reach 237℃within 10 s at an applied voltage of only 2.0 V.Therefore,the alternating multilayered MXene/CNT film breaks through the performance balance limit,showing a great prospect for the future.展开更多
The conventional wisdom holds that CMOS devices cannot be scaled much further from where they are today because of several device physics limitations such as the large tunneling current in very thin gate dielectrics. ...The conventional wisdom holds that CMOS devices cannot be scaled much further from where they are today because of several device physics limitations such as the large tunneling current in very thin gate dielectrics. It is shown that alternative device structures can allow CMOS transistors to scale by another 20 times. That is as large a factor of scaling as what the semiconductor industry accomplished in the past 25 years. There will be many opportunities and challenges in finding novel device structures and new processing techniques, and in understanding the physics of future devices.展开更多
In this paper, spatial channel pairing(SCP) is introduced to coherent combining at the relay in relay networks. Closed-form solution to optimal coherent combining is derived. Given coherent combining, the approximate ...In this paper, spatial channel pairing(SCP) is introduced to coherent combining at the relay in relay networks. Closed-form solution to optimal coherent combining is derived. Given coherent combining, the approximate SCP solution is presented. Finally, an alternating iterative structure is developed. Simulation results and analysis show that, given the symbol error rate and data rate, the proposed alternating iterative structure achieves signal-to-noise ratio gains over existing schemes in maximum ratio combining(MRC) plus matched filter,MRC plus antenna selection, and distributed space-time block coding due to the use of SCP and iterative structure.展开更多
基金This work was financially supported by National Key Research and Development Program of China(No.2016YFB0300500)the National Natural Science Foundation of China(No.51771215)+1 种基金the Ningbo Major Special Projects of the Plan“Science and Technology Innovation 2025”(No.2018B10084)K.C.Wong Magna Fund in Ningbo University。
文摘Electromagnetic interference(EMI)shielding materials with ultrathin,flexible,superior mechanical and thermal management properties are highly desirable for smart and wearable electronics.Here,ultrathin and flexible Ni/Cu/metallic glass/Cu/Ni(Ni/Cu/MG)multilayer composite with alternate magnetic and electrical structures was designed via facial electroless plating of Cu and Ni on an Fe-based metallic glass.The resultant 0.02 mm-thick Ni/Cu/MG composite displays a superior EMI shielding effectiveness(EMI SE)of 35 dB and a great EMI SE/t of 1750 dB/mm,which is greater than those of composites with monotonous multilayer or homogeneous structures.The improved EMI SE originates from the massive ohmic losses,the enhanced internal reflection/absorption,and the abundant interfacial polarization loss.Particularly,Ni/Cu/MG exhibits a high tensile strength of up to 1.2 GPa and outstanding mechanical stability,enabling the EMI SE remains unchanged after 10,000 times of bending.Moreover,Ni/Cu/MG has excellent Joule heating characteristics and thermal stability,which is very suitable for heating components of wearable hyperthermia devices.
基金financially supported by the National Natural Science Foundation of China(Nos.21604063 and 52173010)the Program for Prominent Young College Teachers of Tianjin Educational Committee。
文摘Three alternating conjugated polymers,namely PFTP,PCz TP,and PSi TP,which combine a thieno[3,4-b]pyrazine(TP)unit with different benzene-based donor units such as 9,9-dioctylfluorene,9-heptadecyl-9H-carbazole and 5,5-dioctyl-5H-dibenzo[b,d]silole,were synthesized in good yield(>85%)and high molecular weight up to Mn=5.82×10^(4) via direct arylation polymerization(DAr P).All the resultant polymers exhibit moderate bandgap of about 1.80 e V and strong deep red/near-infrared emitting in the solid state.Among them,the PSi TP-based electroluminescence(EL)devices with an architecture of ITO/PEDOT:PSS/PTAA/emitting layer/TPBi/Li F/Al give the best performance with a maximum luminance of 2543 cd/m^(2) at 478 m A/cm^(2).This work expands the application scope of high-performance conjugated polymers which can be synthesized by DAr P.
基金supported by the National Natural Science Foundation of China(52303113 and 52273085)the Key Scientific Projects of Colleges and Universities in Henan Province of China(24A430045)the Key Research and Development Project of Henan Province of China(241111232300).
文摘MXene-based multilayered composite films show great promise in electromagnetic interference(EMI)shielding field,but the trade-off between mechanical properties,oxidation resistance and EMI shielding performance remains a huge challenge.Herein,inspired by the architecture of millefeuille,alternating multilayered MXene/carbon nanotube(CNT)films were successfully prepared using an alternating vacuum-assisted filtration method,in which the alternating CNT layers not only act as the mechanical frame and oxidation barrier,but also synergistically enhance the EMI shielding effect of MXene layers through the distinctive“absorption-reflection-reabsorption”mechanism.By optimizing the alternating multilayered structure,the MXene/CNT film with a thickness of 36µm can achieve a remarkable EMI shielding effectiveness(SE)of 81.4 dB across the frequency range of 8.2–26.5 GHz.Meanwhile,the mechanical strength and toughness of the MXene/CNT film reach 83.4 MPa and 7.20 MJ/m^(3),respectively.Moreover,the CNT layer can effectively isolate MXene layer from oxygen,thus enabling the fire/oxidation resistance of the multilayer film in complex environments.Besides,the multilayered composite film exhibits impressive Joule heating capacity,which can reach 237℃within 10 s at an applied voltage of only 2.0 V.Therefore,the alternating multilayered MXene/CNT film breaks through the performance balance limit,showing a great prospect for the future.
基金This research is partially supported by the DARPA Advanced Microelectronics Program, SRC Front EndProcess Project, and NSF. This paper contains a review of UTB and FinFET research published by D. Hisamoto, Y-K. Choi, X. Huang, W-C. Lee, C. Kuo, L. Chan
文摘The conventional wisdom holds that CMOS devices cannot be scaled much further from where they are today because of several device physics limitations such as the large tunneling current in very thin gate dielectrics. It is shown that alternative device structures can allow CMOS transistors to scale by another 20 times. That is as large a factor of scaling as what the semiconductor industry accomplished in the past 25 years. There will be many opportunities and challenges in finding novel device structures and new processing techniques, and in understanding the physics of future devices.
基金Project supported by the Open Research Fund of National Mobile Communications Research Laboratory,Southeast University,China(No.2013D02)the Open Research Fund of National Key Laboratory of Electromagnetic Environment,China Research Institute of Radiowave Propagation(No.201500013)+2 种基金the National Natural Science Foundation of China(Nos.61271230,61472190,and 61501238)the Research Fund for the Doctoral Program of Higher Education of China(No.20113219120019)the Foundation of Cloud Computing and Big Data for Agriculture and Forestry,China(No.117-612014063)
文摘In this paper, spatial channel pairing(SCP) is introduced to coherent combining at the relay in relay networks. Closed-form solution to optimal coherent combining is derived. Given coherent combining, the approximate SCP solution is presented. Finally, an alternating iterative structure is developed. Simulation results and analysis show that, given the symbol error rate and data rate, the proposed alternating iterative structure achieves signal-to-noise ratio gains over existing schemes in maximum ratio combining(MRC) plus matched filter,MRC plus antenna selection, and distributed space-time block coding due to the use of SCP and iterative structure.
