A generalized rate model for free radical copolymerization was proposed. It can be applied not only to the system with the participation of charge-transfer complex (CTC), but also to the system without the participati...A generalized rate model for free radical copolymerization was proposed. It can be applied not only to the system with the participation of charge-transfer complex (CTC), but also to the system without the participation of CTC. The effects of equilibrium constant, total monomer concentration, homo-propagation parameters and reactivity ratios on free monomer, CTC, overall rates, and the contribution of CTC were considered in the simulation. North equation of copolymerization rate as a special case can be derived from the generalized model.展开更多
To measure the pulsed neutron of a pulsed fission source, an organic scintillation fiber （OSF） detector with separation structure has been designed. The proposed detector employs UV optical fibers as the light guide...To measure the pulsed neutron of a pulsed fission source, an organic scintillation fiber （OSF） detector with separation structure has been designed. The proposed detector employs UV optical fibers as the light guide, and the sensitive region of the detector is composed of a linear array of OSFs, which are individually connected to the optical fibers. The other end of the light guide is coupled to a photomultiplier tube. The key properties of the device including the energy response, time response, neutron sensitivity, and radiation effect of the optical fiber were studied. The detector has a relatively high n/γ sensitivity ratio, which increases as the diameter of the OSF decreases, and ratios greater than 10 could be achieved when the diameter of the OSF is less than 0.3 nun. The sensitivity of the detector to neutrons ranges from 10-14 to 10-20 C cm2/n, and has a response time of 3 ns （FWHM）. The proposed detector is also highly flexible. For instance, the probe can be set close to the source, while the PMT can be placed far away from radiation, allowing easy shielding. Due to these characteristics, pulsed fission neutrons in the vicinity of the source can be accurately measured.展开更多
基金Supported by the Doctoral Foundation of the Education Commission of China.
文摘A generalized rate model for free radical copolymerization was proposed. It can be applied not only to the system with the participation of charge-transfer complex (CTC), but also to the system without the participation of CTC. The effects of equilibrium constant, total monomer concentration, homo-propagation parameters and reactivity ratios on free monomer, CTC, overall rates, and the contribution of CTC were considered in the simulation. North equation of copolymerization rate as a special case can be derived from the generalized model.
文摘To measure the pulsed neutron of a pulsed fission source, an organic scintillation fiber （OSF） detector with separation structure has been designed. The proposed detector employs UV optical fibers as the light guide, and the sensitive region of the detector is composed of a linear array of OSFs, which are individually connected to the optical fibers. The other end of the light guide is coupled to a photomultiplier tube. The key properties of the device including the energy response, time response, neutron sensitivity, and radiation effect of the optical fiber were studied. The detector has a relatively high n/γ sensitivity ratio, which increases as the diameter of the OSF decreases, and ratios greater than 10 could be achieved when the diameter of the OSF is less than 0.3 nun. The sensitivity of the detector to neutrons ranges from 10-14 to 10-20 C cm2/n, and has a response time of 3 ns （FWHM）. The proposed detector is also highly flexible. For instance, the probe can be set close to the source, while the PMT can be placed far away from radiation, allowing easy shielding. Due to these characteristics, pulsed fission neutrons in the vicinity of the source can be accurately measured.
