The China National Council of Light Industry is the reshuffled former Ministry of Light Industry. It began operation in Beijing on July 15, 1993. Chairman Yu Zhen gave the following introduction on the council’s work...The China National Council of Light Industry is the reshuffled former Ministry of Light Industry. It began operation in Beijing on July 15, 1993. Chairman Yu Zhen gave the following introduction on the council’s work: The China National Council of Light Industry retains the administration functions and responsibilities of the former Ministry of Light Industry. Its functions of coordination, service展开更多
The light output functions for protons of ST-401 and BC-408 plastic scintillators were measured using white neutron source produced by the 9Be（d,n） 10B reaction at the HI-13 Tandem Accelerator at China Institute of ...The light output functions for protons of ST-401 and BC-408 plastic scintillators were measured using white neutron source produced by the 9Be（d,n） 10B reaction at the HI-13 Tandem Accelerator at China Institute of Atomic Energy（CIAE）.The LOFs of plastic scintillators for protons in the energy range of 0.5-16.5 MeV were obtained by the time-of-flight（TOF） technique and an iterative procedure.Two parameters（kB and C） were deduced by fitting the experimental data.展开更多
Working memory is one of the essential higher cognitive functions that actively holds behaviorally-relevant information essential for guiding subsequent actions. It includes subsystems that store and manipulate single...Working memory is one of the essential higher cognitive functions that actively holds behaviorally-relevant information essential for guiding subsequent actions. It includes subsystems that store and manipulate singlemode or multi-modal sensory information, e.g., spatial information, visual images, auditory scenes, olfactory objects, or any combination of these. In addition to merely holding a certain amount of information for a short period of time, as is generally believed, the cognitive processes involved are far more complex, including the executive and attentional control of short-term memory, permitting interim integration, and the processing, disposal, and retrieval of information. Evolution-wise, working memory is essential for the behavioral flexibility that allows humans and animals to quickly adapt to rapidly changing environments.展开更多
Recently, Sandia Laboratories developed a neutron scatter camera to detect special nuclear materials. This camera exhibits the following advantages: high efficiency, direction discrimination, neutron-gamma discriminat...Recently, Sandia Laboratories developed a neutron scatter camera to detect special nuclear materials. This camera exhibits the following advantages: high efficiency, direction discrimination, neutron-gamma discrimination ability, and wide field of view. However, using the direct projection method, the angular resolution of this camera is limited by uncertainties in the energies estimated from pulse height and time of flight measurements. In this study, we established an eight-element neutron scatter camera and conducted the experiment with a ^(252)Cf neutron source. The results show that it has an angular resolution better than 8°(1s) and a detection efficiency of approximately 2.6′10-4. Using maximum likelihood expectation maximization method, the image artifact was eliminated, and the angular resolution was improved. We proposed an average scattering angle method to estimate the scattering energy of neutrons and Compton gamma rays. As such, we can obtain a recognizable image and energy spectrum of the source with some degradation of energy and image resolutions. Finally, a newly measured light response function based on the MPD^(-4) device was used for image reconstruction. Although we did not obtain a better result than that of the standard light response function, we have observed the effects of light response function on image reconstruction.展开更多
文摘The China National Council of Light Industry is the reshuffled former Ministry of Light Industry. It began operation in Beijing on July 15, 1993. Chairman Yu Zhen gave the following introduction on the council’s work: The China National Council of Light Industry retains the administration functions and responsibilities of the former Ministry of Light Industry. Its functions of coordination, service
文摘The light output functions for protons of ST-401 and BC-408 plastic scintillators were measured using white neutron source produced by the 9Be（d,n） 10B reaction at the HI-13 Tandem Accelerator at China Institute of Atomic Energy（CIAE）.The LOFs of plastic scintillators for protons in the energy range of 0.5-16.5 MeV were obtained by the time-of-flight（TOF） technique and an iterative procedure.Two parameters（kB and C） were deduced by fitting the experimental data.
文摘Working memory is one of the essential higher cognitive functions that actively holds behaviorally-relevant information essential for guiding subsequent actions. It includes subsystems that store and manipulate singlemode or multi-modal sensory information, e.g., spatial information, visual images, auditory scenes, olfactory objects, or any combination of these. In addition to merely holding a certain amount of information for a short period of time, as is generally believed, the cognitive processes involved are far more complex, including the executive and attentional control of short-term memory, permitting interim integration, and the processing, disposal, and retrieval of information. Evolution-wise, working memory is essential for the behavioral flexibility that allows humans and animals to quickly adapt to rapidly changing environments.
基金supported by the National Natural Science Fundation of China(Grant Nos.1110510611375144&11275153)
文摘Recently, Sandia Laboratories developed a neutron scatter camera to detect special nuclear materials. This camera exhibits the following advantages: high efficiency, direction discrimination, neutron-gamma discrimination ability, and wide field of view. However, using the direct projection method, the angular resolution of this camera is limited by uncertainties in the energies estimated from pulse height and time of flight measurements. In this study, we established an eight-element neutron scatter camera and conducted the experiment with a ^(252)Cf neutron source. The results show that it has an angular resolution better than 8°(1s) and a detection efficiency of approximately 2.6′10-4. Using maximum likelihood expectation maximization method, the image artifact was eliminated, and the angular resolution was improved. We proposed an average scattering angle method to estimate the scattering energy of neutrons and Compton gamma rays. As such, we can obtain a recognizable image and energy spectrum of the source with some degradation of energy and image resolutions. Finally, a newly measured light response function based on the MPD^(-4) device was used for image reconstruction. Although we did not obtain a better result than that of the standard light response function, we have observed the effects of light response function on image reconstruction.
