SMART （system-integrated modular advanced reactor） is a small-sized advanced integral reactor with a rated thermal power of 330 MW. It can produce 100 MW of electricity, or 90 MW of electricity and 40,000 t of desal...SMART （system-integrated modular advanced reactor） is a small-sized advanced integral reactor with a rated thermal power of 330 MW. It can produce 100 MW of electricity, or 90 MW of electricity and 40,000 t of desalinated water concurrently, which is sufficient for 100,000 residents. SMART technology is a sensible mixture of new innovative design features and proven technologies through a PWR. The enhancement of safety and reliability is realized by incorporating inherent safety features and reliable passive safety systems. The improvement in the economics is achieved through system simplification, component modularization, construction time reduction, and increased plant availability. All technologies and design features implemented into SMART have been proven in industries and/or qualified through the SMART design verification program including comprehensive test and experiments. The full scope of the safety analyses carried out to confirm that the inherent safety-improvement design characteristics and safety systems of SMART ensure reactor safety. After a thorough licensing review, SDA （standard design approval） for SMART was granted on July 4th, 2012 by the Korea NSSC （Nuclear Safety and Security Commission）. This marks the first license for an integral-type reactor in the world. This paper presents the SMART characteristics, safety features and technology validation. The licensing process of SMART is also described.展开更多
Objective We aimed to determine the ef ects of low- and high-energy intensity-modulated radiation therapy （IMRT） photon beams on the target volume planning and on the critical organs in the case of prostate can-cer....Objective We aimed to determine the ef ects of low- and high-energy intensity-modulated radiation therapy （IMRT） photon beams on the target volume planning and on the critical organs in the case of prostate can-cer. Methods Thirty plans were generated by using either 6 MV or 15 MV beams separately, and a combination of both 6 and 15 MV beams. Al plans were generated by using suitable planning objectives and dose con-straints, which were identical across the plans, except the beam energy. The plans were analyzed in terms of their target coverage, conformity, and homogeneity, regardless of the beam energy. Results The mean percentage values of V70 Gy for the rectal wal for the plans with 6 MV, 15 MV, and mixed-energy beams were 16.9%, 17.8%, and 16.4%, respectively, while the mean percentage values of V40 Gy were 53.6%, 52.3%, and 50.4%. The mean dose values to the femoral heads for the 6 MV, 15 MV, and mixed-en-ergy plans were 30.1 Gy, 25.5 Gy, and 25.4 Gy, respectively. The mean integral dose for the 6 MV plans was 10% larger than those for the 15 MV and mixed-energy plans.Conclusion These preliminary results suggest that mixed-energy IMRT plans may be advantageous with respect to the dosimetric characteristics of low- and high-energy beams. Although the reduction of dose to the organs at risk may not be clinical y relevant, in this study, IMRT plans using mixed-energy beams exhibited better OAR sparing and overal higher plan quality for deep-seated tumors.展开更多
Lunar titanium characterization is an important goal of the China Lunar Exploration Program. We suggest a method to determine the lunar titanium abundance using Chang'E-1 IIM (Interference Imaging Spectrometer) im...Lunar titanium characterization is an important goal of the China Lunar Exploration Program. We suggest a method to determine the lunar titanium abundance using Chang'E-1 IIM (Interference Imaging Spectrometer) imagery. Using samples from Apollo and Luna landing sites, the method firstly establishes the spectral parameters that possess good non-linear correlations with lunar titanium abundance. Secondly, the method estimates lunar titanium abundance using a DT-SVM (Decision Tree Method C5.0-Support Vector Machine) method. Namely, according to the established spectral parameters, it uses the C5.0 algorithm to classify the titanium abundance into the 4 classes of very low, low, intermediate and high. Then, in terms of the spectral parameters and the corresponding classes, it employs the SVM to estimate the titanium abundance. The method makes good use of hyperspectral information, analyzes the nonlinear correlations between spectral characteristics of lunar soils and the composition parameter, and well determines the titanium abundance. Validated by the Apollo and Luna station samples, the RMSE (root mean square error) is 0.72wt% TiO2 and the correlation coefficient of the measured and predicted values is 97.29%. So, the method proposed in this paper has a good predictive capability for TiO2 abundance on the lunar surface. The maps of TiO2 content in the partial region of Sinus Iridium, the Apollo 17 landing site and the Apollo 16 landing site are constructed by our method. This paper demonstrates the potential of IIM data for the investigation of lunar surface chemistry and mineralogy.展开更多
文摘SMART （system-integrated modular advanced reactor） is a small-sized advanced integral reactor with a rated thermal power of 330 MW. It can produce 100 MW of electricity, or 90 MW of electricity and 40,000 t of desalinated water concurrently, which is sufficient for 100,000 residents. SMART technology is a sensible mixture of new innovative design features and proven technologies through a PWR. The enhancement of safety and reliability is realized by incorporating inherent safety features and reliable passive safety systems. The improvement in the economics is achieved through system simplification, component modularization, construction time reduction, and increased plant availability. All technologies and design features implemented into SMART have been proven in industries and/or qualified through the SMART design verification program including comprehensive test and experiments. The full scope of the safety analyses carried out to confirm that the inherent safety-improvement design characteristics and safety systems of SMART ensure reactor safety. After a thorough licensing review, SDA （standard design approval） for SMART was granted on July 4th, 2012 by the Korea NSSC （Nuclear Safety and Security Commission）. This marks the first license for an integral-type reactor in the world. This paper presents the SMART characteristics, safety features and technology validation. The licensing process of SMART is also described.
文摘Objective We aimed to determine the ef ects of low- and high-energy intensity-modulated radiation therapy （IMRT） photon beams on the target volume planning and on the critical organs in the case of prostate can-cer. Methods Thirty plans were generated by using either 6 MV or 15 MV beams separately, and a combination of both 6 and 15 MV beams. Al plans were generated by using suitable planning objectives and dose con-straints, which were identical across the plans, except the beam energy. The plans were analyzed in terms of their target coverage, conformity, and homogeneity, regardless of the beam energy. Results The mean percentage values of V70 Gy for the rectal wal for the plans with 6 MV, 15 MV, and mixed-energy beams were 16.9%, 17.8%, and 16.4%, respectively, while the mean percentage values of V40 Gy were 53.6%, 52.3%, and 50.4%. The mean dose values to the femoral heads for the 6 MV, 15 MV, and mixed-en-ergy plans were 30.1 Gy, 25.5 Gy, and 25.4 Gy, respectively. The mean integral dose for the 6 MV plans was 10% larger than those for the 15 MV and mixed-energy plans.Conclusion These preliminary results suggest that mixed-energy IMRT plans may be advantageous with respect to the dosimetric characteristics of low- and high-energy beams. Although the reduction of dose to the organs at risk may not be clinical y relevant, in this study, IMRT plans using mixed-energy beams exhibited better OAR sparing and overal higher plan quality for deep-seated tumors.
基金supported by the National Natural Science Foundation of China (Grant No. 40902099)the Fundamental Research Funds for the Central Universities,China University of Geosciences (Wuhan) (Grant No. CUG100702)
文摘Lunar titanium characterization is an important goal of the China Lunar Exploration Program. We suggest a method to determine the lunar titanium abundance using Chang'E-1 IIM (Interference Imaging Spectrometer) imagery. Using samples from Apollo and Luna landing sites, the method firstly establishes the spectral parameters that possess good non-linear correlations with lunar titanium abundance. Secondly, the method estimates lunar titanium abundance using a DT-SVM (Decision Tree Method C5.0-Support Vector Machine) method. Namely, according to the established spectral parameters, it uses the C5.0 algorithm to classify the titanium abundance into the 4 classes of very low, low, intermediate and high. Then, in terms of the spectral parameters and the corresponding classes, it employs the SVM to estimate the titanium abundance. The method makes good use of hyperspectral information, analyzes the nonlinear correlations between spectral characteristics of lunar soils and the composition parameter, and well determines the titanium abundance. Validated by the Apollo and Luna station samples, the RMSE (root mean square error) is 0.72wt% TiO2 and the correlation coefficient of the measured and predicted values is 97.29%. So, the method proposed in this paper has a good predictive capability for TiO2 abundance on the lunar surface. The maps of TiO2 content in the partial region of Sinus Iridium, the Apollo 17 landing site and the Apollo 16 landing site are constructed by our method. This paper demonstrates the potential of IIM data for the investigation of lunar surface chemistry and mineralogy.
