We construct a circuit based on PBS and CNOT gates, which can be used to determine whether the input pulse is empty or not according to the detection result of the auxiliary state, while the input state will not be ch...We construct a circuit based on PBS and CNOT gates, which can be used to determine whether the input pulse is empty or not according to the detection result of the auxiliary state, while the input state will not be changed. The circuit can be treated as a pre-detection device. Equipping the pre-detection device in the front of the receiver of the quantum key distribution （QKD） can reduce the influence of the dark count of the detector, hence increasing the secure communication distance significantly. Simulation results show that the secure communication distance can reach 516 km and 479 km for QKD with perfect single photon source and decoy-state QKD with weak coherent photon source, respectively.展开更多
[Objective] In response to pig breeding stage characteristics,the research aimed to design the traceability system to realize the pig product marking which based on RFID technology. [Method] The antenna＇s design meth...[Objective] In response to pig breeding stage characteristics,the research aimed to design the traceability system to realize the pig product marking which based on RFID technology. [Method] The antenna＇s design method of electronic tag and reader antenna were expounded and different antennas were used for testing communication test of RFID system. [Result] When the parameter setup such as data transportation ratio was same,the communication distance of external antenna was farther than RCB antenna; compare with three external antennas,the communication distance of coaxial antenna and wall-hanged antenna were farther. In 500 kbps transfer rate,communication distance was within 28 meters,and in 250 kbps transfer rate,communication distance was within 40 meters. Considered the cost of hardware,the price of wall-hanged antenna was higher than coaxial antenna,so in the same communication distance request,system selected coaxial antenna. [Conclusion] During the pig breeding stage,by dint of electronic tag and reader designed by the research could improve the safety of the pork and fully realize the track of source of food and provide technology support for the transparent management of food safety.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.61372076)the Programme of Introducing Talents of Discipline to Universities,China(Grant No.B08038)the Fundamental Research Funds for the Central Universities,China(Grant No.K5051201021)
文摘We construct a circuit based on PBS and CNOT gates, which can be used to determine whether the input pulse is empty or not according to the detection result of the auxiliary state, while the input state will not be changed. The circuit can be treated as a pre-detection device. Equipping the pre-detection device in the front of the receiver of the quantum key distribution （QKD） can reduce the influence of the dark count of the detector, hence increasing the secure communication distance significantly. Simulation results show that the secure communication distance can reach 516 km and 479 km for QKD with perfect single photon source and decoy-state QKD with weak coherent photon source, respectively.
基金Supported by National Science and Technology Support Plan Subtopic (No. 2006BAD14B04)Yunnan Province Agriculture Science and Technology Innovation Project (2008LA020)~~
文摘[Objective] In response to pig breeding stage characteristics,the research aimed to design the traceability system to realize the pig product marking which based on RFID technology. [Method] The antenna＇s design method of electronic tag and reader antenna were expounded and different antennas were used for testing communication test of RFID system. [Result] When the parameter setup such as data transportation ratio was same,the communication distance of external antenna was farther than RCB antenna; compare with three external antennas,the communication distance of coaxial antenna and wall-hanged antenna were farther. In 500 kbps transfer rate,communication distance was within 28 meters,and in 250 kbps transfer rate,communication distance was within 40 meters. Considered the cost of hardware,the price of wall-hanged antenna was higher than coaxial antenna,so in the same communication distance request,system selected coaxial antenna. [Conclusion] During the pig breeding stage,by dint of electronic tag and reader designed by the research could improve the safety of the pork and fully realize the track of source of food and provide technology support for the transparent management of food safety.
