A single channel measurement system for brain MIT has been built. The system is composed of an exciting source unit,a detecting unit,a rotating and controlling unit,and imaging unit. The experiment results of single c...A single channel measurement system for brain MIT has been built. The system is composed of an exciting source unit,a detecting unit,a rotating and controlling unit,and imaging unit. The experiment results of single channel measurements show that the system output versus the conductivity of the objects was an approximate linear relationship when the diameter of an object was about 9cm and its conductivity was in 0.1 S/m,0.7 S/m,2 S/m,6 S/m. The sensitivit yof the phase detector was 53 mV/degree from -10 to +10 degree.展开更多
A novel deterministic secure quantum communication （DSQC） scheme is presented based on Einstein- Podolsky-Rosen （EPR） pairs and single photons in this study. In this scheme, the secret message can be encoded direc...A novel deterministic secure quantum communication （DSQC） scheme is presented based on Einstein- Podolsky-Rosen （EPR） pairs and single photons in this study. In this scheme, the secret message can be encoded directly on the first particles of the prepared Bell states by simple unitary operations and decoded by performing the Bell-basis measurement after the additional classic information is exchanged. In addition, the strategy with two-step transmission of quantum data blocks and the technique of decoy-particle checking both are exploited to guarantee the security of the communication. Compared with some previous DSQC schemes, this scheme not oniy has a higher resource capacity, intrinsic efficiency and total efficiency, but also is more realizable in practical applications. Security anaJysis shows that the proposed scheme is unconditionally secure against various attacks over an ideal quantum channel and still conditionally robust over a noisy and lossy quantum channel.展开更多
文摘A single channel measurement system for brain MIT has been built. The system is composed of an exciting source unit,a detecting unit,a rotating and controlling unit,and imaging unit. The experiment results of single channel measurements show that the system output versus the conductivity of the objects was an approximate linear relationship when the diameter of an object was about 9cm and its conductivity was in 0.1 S/m,0.7 S/m,2 S/m,6 S/m. The sensitivit yof the phase detector was 53 mV/degree from -10 to +10 degree.
基金Supported by the National Natural Science Foundation of China under Grant No.61272501the National Key Basic Research Program(NKBRP)(973 program)(2012CB315905)the Beijing Natural Science Foundation under Grant No.4132056
文摘A novel deterministic secure quantum communication （DSQC） scheme is presented based on Einstein- Podolsky-Rosen （EPR） pairs and single photons in this study. In this scheme, the secret message can be encoded directly on the first particles of the prepared Bell states by simple unitary operations and decoded by performing the Bell-basis measurement after the additional classic information is exchanged. In addition, the strategy with two-step transmission of quantum data blocks and the technique of decoy-particle checking both are exploited to guarantee the security of the communication. Compared with some previous DSQC schemes, this scheme not oniy has a higher resource capacity, intrinsic efficiency and total efficiency, but also is more realizable in practical applications. Security anaJysis shows that the proposed scheme is unconditionally secure against various attacks over an ideal quantum channel and still conditionally robust over a noisy and lossy quantum channel.
