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
Filial piety in traditional Chinese culture is an essential variable in explaining intergenerational interaction.However,previous studies have not clarified whether older adults’filial responsibility expectations mat...Filial piety in traditional Chinese culture is an essential variable in explaining intergenerational interaction.However,previous studies have not clarified whether older adults’filial responsibility expectations matched children’s filial support and the effects of the filial discrepancy on their life satisfaction and loneliness.The latent profile analysis showed that older adults were divided into two groups:(1)high expectations and support,and(2)low expectations and support.The results showed that compared with older adults with low expectations and low support,those with high expectations and high support reported higher life satisfaction and lower loneliness.Additionally,social support played a moderating role in the effect of the groups of older adults on life satisfaction and loneliness.Our conclusion shows that filial support is an essential factor influencing older adult life satisfaction and loneliness,and social support is an effective supplement to filial support.展开更多
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.
基金supported by the Key Research Base of Humanities and Social Sciences of the Ministry of Education(Grant/Award Number:22JJD190010)the Ministry of Education of Humanities and Social Science Project(Grant/Award Number:23YJA880026)+1 种基金the Fundamental Research Funds for the Central Universities(Grant/Award Number:GK202303003)the National Natural Science Foundation of China(Grant/Award Number:62377035).
文摘Filial piety in traditional Chinese culture is an essential variable in explaining intergenerational interaction.However,previous studies have not clarified whether older adults’filial responsibility expectations matched children’s filial support and the effects of the filial discrepancy on their life satisfaction and loneliness.The latent profile analysis showed that older adults were divided into two groups:(1)high expectations and support,and(2)low expectations and support.The results showed that compared with older adults with low expectations and low support,those with high expectations and high support reported higher life satisfaction and lower loneliness.Additionally,social support played a moderating role in the effect of the groups of older adults on life satisfaction and loneliness.Our conclusion shows that filial support is an essential factor influencing older adult life satisfaction and loneliness,and social support is an effective supplement to filial support.
