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This work is interested in verifying and analyzing the advanced neutronics assembly program KYLIN V2.0. Assembly calculations are an integral part of the two-step calculation for core design, and their accuracy directly affects the results of the core physics calculations. In this paper, we use the Doppler coefficient numerical benchmark problem and CPR1000 AFA-3G fuel assemblies to verify and analyze the advanced neutronics assembly program KYLIN V2.0 developed by the Nuclear Power Institute of China. The analysis results show that the Doppler coefficients calculated by KYLIN V2.0 are in good agreement with the results of other well-known nuclear engineering design software in the world; the power distributions of AFA-3G fuel assemblies are in good agreement with the results of the RMC calculations, it’s error distribution is in accordance with the normal distribution. It shows that KYLIN V2.0 has high calculation accuracy and meets the engineering design requirements.

The current diagnoses of Alzheimer’s disease (AD) mainly rely on such measures as amyloid-β (Aβ) and tau neuropathology biomarkers in vivo via cerebrospinal fluid (CSF) and positron emission tomography (PET) imaging, which had been systematically studied in Caucasian individuals, whereas diagnostic performances of these approaches in Chinese dementia population still remain unclear. This study investigated the associations between the levels of CSF core AD biomarkers, including phosphorylated tau (p-Tau181), total tau (t-Tau), Aβ42, and Aβ40 measured by the single-molecule array (Simoa) and cerebral Aβ deposition status assessed by 18F-Florbetapir PET (Aβ PET), and evaluated the predictive values of CSF core AD biomarkers in discriminating Aβ PET status in a clinical dementia cohort of the Chinese population, which consisted of patients with mild cognitive impairment (MCI), AD dementia, and non-Alzheimer’s dementia disease (Non-ADD). Global standard uptake value ratios (SUVRs) were calculated by Aβ PET, which was divided into positive (Aβ+) and negative (Aβ−) through visual analysis. CSF p-Tau181 and p-Tau181/t-Tau ratio were positively correlated with the global SUVR, while CSF Aβ42 and Aβ42/Aβ40 ratio were negatively correlated with the global SUVR. CSF Aβ40 has the highest predictive value in discriminating the MCI group from the AD group, while CSF p-Tau181 was applied to discriminate the AD group from the non-ADD group. CSF Aβ42/Aβ40 ratio, as the optimal predictive factor, was combined with APOE ε4 status rather than age and education, which could improve the predictive ability in differentiating the Aβ+ group from the Aβ– group. The results reveal the universal applicability of CSF core AD biomarkers and Aβ PET imaging in Chinese dementia population, which is helpful in clinical practice and drug trials in China.

In this study, the dynamic characteristics of accelerator-driven subcritical reactor (ADSR) under beam transients with high heterogeneity of neutron flux in time-space are investigated. Multi-mode core few-group constants are generated by three kinds of neutron fluxes: steady state of ADSR, λ-eigenvalue fundamental wave, and α-eigenvalue fundamental wave. The proposed few-group constants overcome the limitation of single few-group constant generated by two-step method that cannot consider the variation in neutron flux density and neutron energy spectrum with time and space. Compared to the existing few-group constants generated by two-step method under different operating conditions, the self-adapting multi-mode core few-group constants exhibit higher accuracy in the case of following two modes: steady-state mode of ADSR in the starting process and λ-eigenvalue mode in the beam trip condition. Overall, this research provides useful insights on neutron kinetics and can boost the development of ADSRs.