Future wireless communication systemembraces physical-layer signal detection with highsensitivity, especially in the microwave photon level.Currently, the receiver primarily adopts the signal detection based on semi-c...Future wireless communication systemembraces physical-layer signal detection with highsensitivity, especially in the microwave photon level.Currently, the receiver primarily adopts the signal detection based on semi-conductor devices for signal detection, while this paper introduces high-sensitivityphoton-level microwave detection based on superconducting structure. We first overview existing works onthe photon-level communication in the optical spectrum as well as the microwave photon-level sensingbased on superconducting structure in both theoreticaland experimental perspectives, including microwavedetection circuit model based on Josephson junction,microwave photon counter based on Josephson junction, and two reconstruction approaches under background noise. In addition, we characterize channelmodeling based on two different microwave photondetection approaches, including the absorption barrierand the dual-path Handury Brown-Twiss (HBT) experiments, and predict the corresponding achievablerates. According to the performance prediction, it isseen that the microwave photon-level signal detectioncan increase the receiver sensitivity compared withthe state-of-the-art standardized communication system with waveform signal reception, with gain over 10dB.展开更多
Metamaterials(MTM)can enhance the properties of microwaves and also exceed some limitations of devices used in technical practice.Note that the antenna is the element for realizing a microwave imaging(MWI)system since...Metamaterials(MTM)can enhance the properties of microwaves and also exceed some limitations of devices used in technical practice.Note that the antenna is the element for realizing a microwave imaging(MWI)system since it is where signal transmission and absorption occur.Ultra-Wideband(UWB)antenna superstrates with MTM elements to ensure the signal transmitted from the antenna reaches the tumor and is absorbed by the same antenna.The lack of conventional head imaging techniques,for instance,Magnetic Resonance Imaging(MRI)and Computerized Tomography(CT)-scan,has been demonstrated in the paper focusing on the point of failure of these techniques for prompt diagnosis and portable systems.Furthermore,the importance ofMWIhas been addressed elaborately to portray its effectiveness and aptness for a primary tumor diagnosis.Other than that,MTM element designs have been discussed thoroughly based on their performances towards the contributions to the better image resolution of MWI with detailed reasonings.This paper proposes the novel design of a Zeroindex Split RingResonator(SRR)MTMelement superstrate with a UWB antenna implemented in MWI systems for detecting tumor.The novel design of the MTM enables the realization of a high gain of a superstrate UWB antenna with the highest gain of 5.70 dB.Besides that,the MTM imitates the conduct of the zeroreflection phase on the resonance frequency,which does not exist.An antenna with an MTM unit is of a 7×4 and 10×5 Zero-index SRR MTM element that acts as a superstrate plane to the antenna.Apart from that,Rogers(RT5880)substrate material is employed to fabricate the designed MTM unit cell,with the following characteristics:0.51mm thickness,the loss tangent of 0.02,as well as the relative permittivity of 2.2,with Computer Simulation Technology(CST)performing the simulation and design.Both MTM unit cells of 7×4 and 10×5 attained 0°with respect to the reflection phase at the 2.70 GHz frequency band.The first design,MTM Antenna Design 1,consists of a 7×4 MTM unit cell that observed a rise of 5.70 dB with a return loss(S11)−20.007 dB at 2.70 GHz frequency.The second design,MTM Antenna Design 2,consists of 10×5 MTM unit cells that recorded a gain of 5.66 dB,having the return loss(S11)−19.734 dB at 2.70 GHz frequency.Comparing these two MTM elements superstrates with the antenna,one can notice that the 7×4 MTM element shape has a low number of the unit cell with high gain and is a better choice than the 10×5 MTM element in realizing MTM element superstrates antenna for MWI.展开更多
In recent years, the formate ion （HCO2^-） as a kind of hole-to-electron converter has attracted much attention of photographic researchers. The formate ions can trap photo-generated holes, eliminate or reduce the el...In recent years, the formate ion （HCO2^-） as a kind of hole-to-electron converter has attracted much attention of photographic researchers. The formate ions can trap photo-generated holes, eliminate or reduce the electron loss caused by electron-hole recombination in latent image formation process. Through the hole-to-electron conversion, it can also release an extra electron or electron carrier, improving photosensitivity. In this paper the microwave absorption and dielectric spectrum detection technique is used to detect the time evolution behaviour of free photoelectrons generated by 35ps laser pulses in cubic AgCl emulsions doped with formate ions. The influence of different doping conditions of formate ions on the photoelectron decay kinetics of AgC1 is analysed. It is found that when the HCO2^- content is 10^-3mol/mol Ag and the doping position is 90% the electron decay time and lifetime reach their maxima due to the efficient trap of holes by formate ions.展开更多
The network morphology is considered superior to nanoparticles for electrocatalysts to achieve high performance in high-flux energy devices.However,the preparation of network-type electrocatalysts and their electrodes...The network morphology is considered superior to nanoparticles for electrocatalysts to achieve high performance in high-flux energy devices.However,the preparation of network-type electrocatalysts and their electrodes is relatively complex and low in productivity.Here,we report a nano-welding method to transform ZIF-8 nanoparticles into a large Fe-N-C 3D network using Fe/Zn-hexamethylenetetramine(FeZnHMT)as a reactive multifunctional solder.During the carbonization,FeZnHMT welds the ZIF-8 nanoparticles into a network and reacts with them to form concave surfaces loaded with dense Fe-N4active sites.The resulting Fe-N-C network has a size of tens of microns and is rich in submicron voids,making it easy to handle during electrode preparation.As characterized by an advanced microwave technique,the Fe-N-C network largely reduces the electrical contact resistance and promotes gas/water transports in the catalyst layer,thus achieving an extremely high power density of 1.355 W cm^(-2)in a H_(2)-O_(2)proton exchange membrane fuel cell.The nano-welding method does not require special equipment and presents an easy,low-cost,and scalable method for producing network-structured single-atom catalysts.展开更多
Background Ali CMB polarization telescope(AliCPT)project is a well-timed and well-planned ground-based CMB project in Ali(Nagri)area of Tibet,China.It has been approved at the end of 2016.Aims To give an introduction ...Background Ali CMB polarization telescope(AliCPT)project is a well-timed and well-planned ground-based CMB project in Ali(Nagri)area of Tibet,China.It has been approved at the end of 2016.Aims To give an introduction to the detection technology of AliCPT.Method The whole receiver of AliCPT is introduced and discussed,including the optics,the cryostat,the preliminary design of focal plane TES bolometers,multiplexing SQUID readout,and so on.Conclusions The raw sensitivity ofr will reach below 0.001 by 10-year observation as AliCPT project being carried out and upgraded.展开更多
We provide an overview of the recent progresses on the system architecture design and performance prediction for microwave signal detection under weak signal intensity regime,up to quantumized level.The technique road...We provide an overview of the recent progresses on the system architecture design and performance prediction for microwave signal detection under weak signal intensity regime,up to quantumized level.The technique roadmap includes two perspectives,the opto-electro-mechanical(OEM)and superconducting devices.For the former one,we first overview the concept of OEM,and then introduce the signal detection based on capacitive-opto-electro-mechanical systems and piezoopto-electro-mechanical systems.For the latter one,we first overview the concept and architecture of Josephson junction,and then introduce the signal detection based on superconducting Hanbury Brown-Twiss(HBT)experiments andΛenergy-level splitting system.Besides,we review the microwave detection based on Rydberg atom system.We believe that this overview can provide a guidance for future transmission limit,signal processing,detection device fabrication and real experiments.展开更多
We propose aΛ-type superconducting three-energy-level device-based communication system for extremely weak microwave communication scenarios,for example,long-distance deep-space communication.We provide a system diag...We propose aΛ-type superconducting three-energy-level device-based communication system for extremely weak microwave communication scenarios,for example,long-distance deep-space communication.We provide a system diagram and propose the frame synchronization and power estimation approaches based on pre-defined synchronization sequences.Based on the microwave response characteristics of the superconducting three-energy-level system,we further investigate the optimization of synchronization sequence and information symbol modulation.We show that three-energy-level systems with weak Markovianity can be approximated using independent identical distribution methods to obtain optimal synchronization sequences,and the optimal modulation is asymmetric.The proposed system design and optimization approaches are evaluated by numerical results.Moreover,we investigate the performance of the three-energy-level communication system in the presence of interference.Simulation results show that the three-energy-level communication system can tolerate more than 10 dB interference compared to long term evolution(LTE)systems and achieve the same communication rate for the same bandwidth and temperature.展开更多
基金National Key Research and Development Program of China(Grant No.2018YFB1801904)Key Program of National Natural Science Foundation of China(Grant No.61631018)Key Research Program of Frontier Sciences of CAS(Grant No.QYZDY-SSW-JSC003).
文摘Future wireless communication systemembraces physical-layer signal detection with highsensitivity, especially in the microwave photon level.Currently, the receiver primarily adopts the signal detection based on semi-conductor devices for signal detection, while this paper introduces high-sensitivityphoton-level microwave detection based on superconducting structure. We first overview existing works onthe photon-level communication in the optical spectrum as well as the microwave photon-level sensingbased on superconducting structure in both theoreticaland experimental perspectives, including microwavedetection circuit model based on Josephson junction,microwave photon counter based on Josephson junction, and two reconstruction approaches under background noise. In addition, we characterize channelmodeling based on two different microwave photondetection approaches, including the absorption barrierand the dual-path Handury Brown-Twiss (HBT) experiments, and predict the corresponding achievablerates. According to the performance prediction, it isseen that the microwave photon-level signal detectioncan increase the receiver sensitivity compared withthe state-of-the-art standardized communication system with waveform signal reception, with gain over 10dB.
基金the Fundamental Research Grant Scheme (FRGS/1/2018/ICT06/UNIMAP/02/1)of the Ministry of Higher Education of Malaysia.
文摘Metamaterials(MTM)can enhance the properties of microwaves and also exceed some limitations of devices used in technical practice.Note that the antenna is the element for realizing a microwave imaging(MWI)system since it is where signal transmission and absorption occur.Ultra-Wideband(UWB)antenna superstrates with MTM elements to ensure the signal transmitted from the antenna reaches the tumor and is absorbed by the same antenna.The lack of conventional head imaging techniques,for instance,Magnetic Resonance Imaging(MRI)and Computerized Tomography(CT)-scan,has been demonstrated in the paper focusing on the point of failure of these techniques for prompt diagnosis and portable systems.Furthermore,the importance ofMWIhas been addressed elaborately to portray its effectiveness and aptness for a primary tumor diagnosis.Other than that,MTM element designs have been discussed thoroughly based on their performances towards the contributions to the better image resolution of MWI with detailed reasonings.This paper proposes the novel design of a Zeroindex Split RingResonator(SRR)MTMelement superstrate with a UWB antenna implemented in MWI systems for detecting tumor.The novel design of the MTM enables the realization of a high gain of a superstrate UWB antenna with the highest gain of 5.70 dB.Besides that,the MTM imitates the conduct of the zeroreflection phase on the resonance frequency,which does not exist.An antenna with an MTM unit is of a 7×4 and 10×5 Zero-index SRR MTM element that acts as a superstrate plane to the antenna.Apart from that,Rogers(RT5880)substrate material is employed to fabricate the designed MTM unit cell,with the following characteristics:0.51mm thickness,the loss tangent of 0.02,as well as the relative permittivity of 2.2,with Computer Simulation Technology(CST)performing the simulation and design.Both MTM unit cells of 7×4 and 10×5 attained 0°with respect to the reflection phase at the 2.70 GHz frequency band.The first design,MTM Antenna Design 1,consists of a 7×4 MTM unit cell that observed a rise of 5.70 dB with a return loss(S11)−20.007 dB at 2.70 GHz frequency.The second design,MTM Antenna Design 2,consists of 10×5 MTM unit cells that recorded a gain of 5.66 dB,having the return loss(S11)−19.734 dB at 2.70 GHz frequency.Comparing these two MTM elements superstrates with the antenna,one can notice that the 7×4 MTM element shape has a low number of the unit cell with high gain and is a better choice than the 10×5 MTM element in realizing MTM element superstrates antenna for MWI.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10354001, 60478033, and 10274017）, the Natural Science Foundation of Hebei Province of China （Grant No 603138） and the Doctorate Foundation of Hebei Province of China （Grant No B2003119）.
文摘In recent years, the formate ion （HCO2^-） as a kind of hole-to-electron converter has attracted much attention of photographic researchers. The formate ions can trap photo-generated holes, eliminate or reduce the electron loss caused by electron-hole recombination in latent image formation process. Through the hole-to-electron conversion, it can also release an extra electron or electron carrier, improving photosensitivity. In this paper the microwave absorption and dielectric spectrum detection technique is used to detect the time evolution behaviour of free photoelectrons generated by 35ps laser pulses in cubic AgCl emulsions doped with formate ions. The influence of different doping conditions of formate ions on the photoelectron decay kinetics of AgC1 is analysed. It is found that when the HCO2^- content is 10^-3mol/mol Ag and the doping position is 90% the electron decay time and lifetime reach their maxima due to the efficient trap of holes by formate ions.
基金supported by the Natural Science Foundation of Beijing Municipality(Z200012)the National Natural Science Foundation of China(U21A20328,21975010,22409013)+3 种基金the National Key Research and Development Program of China(2021YFB4000601)the China Postdoctoral Science Foundation(2022M720013)the Postdoctoral Fellowship Program of China Postdoctoral Science Fund(GZB20230926)the Fundamental Research Funds for the Central Universities。
文摘The network morphology is considered superior to nanoparticles for electrocatalysts to achieve high performance in high-flux energy devices.However,the preparation of network-type electrocatalysts and their electrodes is relatively complex and low in productivity.Here,we report a nano-welding method to transform ZIF-8 nanoparticles into a large Fe-N-C 3D network using Fe/Zn-hexamethylenetetramine(FeZnHMT)as a reactive multifunctional solder.During the carbonization,FeZnHMT welds the ZIF-8 nanoparticles into a network and reacts with them to form concave surfaces loaded with dense Fe-N4active sites.The resulting Fe-N-C network has a size of tens of microns and is rich in submicron voids,making it easy to handle during electrode preparation.As characterized by an advanced microwave technique,the Fe-N-C network largely reduces the electrical contact resistance and promotes gas/water transports in the catalyst layer,thus achieving an extremely high power density of 1.355 W cm^(-2)in a H_(2)-O_(2)proton exchange membrane fuel cell.The nano-welding method does not require special equipment and presents an easy,low-cost,and scalable method for producing network-structured single-atom catalysts.
基金This work is supported by Strategy Pilot B Programme of CAS(Grant No.XDB23020000)National Science Foundation of China(Grant Nos.11653001,11653004)Key International S&T Cooperation Projects of MOST(ministry of science and technology)(No.2016YFE0104700).
文摘Background Ali CMB polarization telescope(AliCPT)project is a well-timed and well-planned ground-based CMB project in Ali(Nagri)area of Tibet,China.It has been approved at the end of 2016.Aims To give an introduction to the detection technology of AliCPT.Method The whole receiver of AliCPT is introduced and discussed,including the optics,the cryostat,the preliminary design of focal plane TES bolometers,multiplexing SQUID readout,and so on.Conclusions The raw sensitivity ofr will reach below 0.001 by 10-year observation as AliCPT project being carried out and upgraded.
基金National Key Research and Development Program of China(2018YFB1801904)Key Program of National Natural Science Foundation of China(61631018)+1 种基金Key Research Program of Frontier Sciences of CAS(QYZDY-SSWJSC003)Huawei Innovation Project。
文摘We provide an overview of the recent progresses on the system architecture design and performance prediction for microwave signal detection under weak signal intensity regime,up to quantumized level.The technique roadmap includes two perspectives,the opto-electro-mechanical(OEM)and superconducting devices.For the former one,we first overview the concept of OEM,and then introduce the signal detection based on capacitive-opto-electro-mechanical systems and piezoopto-electro-mechanical systems.For the latter one,we first overview the concept and architecture of Josephson junction,and then introduce the signal detection based on superconducting Hanbury Brown-Twiss(HBT)experiments andΛenergy-level splitting system.Besides,we review the microwave detection based on Rydberg atom system.We believe that this overview can provide a guidance for future transmission limit,signal processing,detection device fabrication and real experiments.
基金the National Natural Science Foundation of China.62171428Key Research Program of Frontier Sciences of CAS.QYZDY-SSW-JSC003。
文摘We propose aΛ-type superconducting three-energy-level device-based communication system for extremely weak microwave communication scenarios,for example,long-distance deep-space communication.We provide a system diagram and propose the frame synchronization and power estimation approaches based on pre-defined synchronization sequences.Based on the microwave response characteristics of the superconducting three-energy-level system,we further investigate the optimization of synchronization sequence and information symbol modulation.We show that three-energy-level systems with weak Markovianity can be approximated using independent identical distribution methods to obtain optimal synchronization sequences,and the optimal modulation is asymmetric.The proposed system design and optimization approaches are evaluated by numerical results.Moreover,we investigate the performance of the three-energy-level communication system in the presence of interference.Simulation results show that the three-energy-level communication system can tolerate more than 10 dB interference compared to long term evolution(LTE)systems and achieve the same communication rate for the same bandwidth and temperature.
