分类： 核科学技术 >> 粒子加速器 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： Particle induced X-ray Emission (PIXE) was used to analyze the proto-porcelain excavated from Tingziqiao kiln site of Warring States (475221 BC) in Deqing County of Zhejiang Province, China. It was found that the porcelain body and glaze differ from each other in recipes. The porcelain clay of high silicon and low aluminum might be used to make the body of proto-porcelain. Lime and plant or wood ashes might be added into the glaze of the proto-porcelain. Cluster analysis was done to reveal the compositional relationship between the proto-porcelain samples.
分类： 核科学技术 >> 裂变堆工程技术 提交时间： 2021-12-31
摘要： Nuclear data are the cornerstones of reactor physics and shielding calculations. Recently, China released CENDL-3.2 in 2020, and the United States released ENDF/B-VIII.0 in 2018. Therefore, it is necessary to comprehensively evaluate the criticality computing performance of these newly released evaluated nuclear libraries. In this study, we used the NJOY2016 code to generate ACE format libraries based on the latest neutron data libraries (including CENDL-3.2, JEFF3.3, ENDF/B-VIII.0, and JENDL4.0). The MCNP code was used to conduct a detailed analysis of fission nuclides, including 235U, 233U, and 239Pu, in different evaluated nuclear data libraries based on 100 benchmarks. The criticality calculation performance of each library was evaluated using three statistical parameters: , , and . Analysis of the parameter showed that CENDL-3.1 and JENDL-4.0 both had >10 benchmarks that exceeded 3σ, whereas CENDL-3.2, ENDFB-VIII.0, and JEFF-3.3 had, 7, 5, and 4 benchmarks, respectively, exceeding 3σ. The ENDF/B-VII.1 library performed best, with only two benchmarks exceeding 3σ. Compared with CENDL-3.1, CENDL-3.2 offers an improvement in criticality calculations. Compared with the JEFF-3.3 and ENDF/B-VIII.0 libraries, CENDL3.2 performs better in the calculation of the 233U assemblies, but it performs poorly in the pusl11 series case calculation of the 239Pu assemblies, and thus further improvement is needed.
分类： 核科学技术 >> 裂变堆工程技术 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： The safety analysis code SCTRAN for SCWR (Super Critical Water Reactor) is modified to own the capability to assess the radiation heat transfer with developing a two-dimensional heat conduction solution scheme and incorporating a radiation heat transfer model. The verification of the developed radiation heat transfer model is conducted through code-to-code comparison with CATHENA. The results show that the modified SCTRAN code is successful for that the maximum absolute error and relative error of the surface temperature between results of SCTRAN and CATHENA are 6.1 ℃ and 0.9%, which are acceptable in temperature prediction. Then, with the modified SCTRAN code, the loss of coolant accident with a total loss of emergency core cooling system (LOCA/LOECC) of Canadian-SCWR is carried out to evaluate its no-core-melt concept. The following conclusions are achieved: 1) in the process of LOCA, the decay heat can be totally removed by the radiation heat transfer and the natural convection of the high-temperature coolant, even without an intervention of ECCS (Emergency Core Cooling System); 2) The peak cladding temperature of the fuel pins in the inner and outer rings of the high power group are 1236 ℃ and 1177 ℃ respectively, which are much lower than the melting point of the fuel sheath. It indicates that the Canadian-SCWR can achieve no-core-melt concept under LOCA/LOECC.
分类： 生物学 >> 生物物理学 >> 肿瘤学 提交时间： 2016-05-11
Wang, Fei
Yang, Li
Gao, Qun
Huang, Lan
Zhang, Yi
Wang, Fei
Zhang, Yi
Gao, Qun
Wang, Liping
Zhang, Yi
Wang, Jing
Wang, Shengdian
Zhang, Bin
摘要： Malignant pleural effusion (MPE) is a common complication caused by malignant diseases. However, subjectivity, poor sensitivity, and substantial false-negative rates of cytology assay hamper accurate MPE diagnosis. The aim of this study was to assess whether CD163+CD14+ tumor-associated macrophages (TAMs) could be used as a biomarker for enabling sensitive and specific MPE diagnosis. Pleural effusion samples and peripheral blood samples were collected from 50 MPE patients and 50 non-malignant pleural effusion (NMPE) patients, respectively. Flow cytometry was performed to analyze cell phenotypes, and RT-qPCR was used to detect cytokine expression in these monocytes and macrophages. A blinded validation study (n = 40) was subsequently performed to confirm the significance of CD163+CD14+ TAMs in MPE diagnosis. Student's t test, rank sum test, and receiver operating characteristic curve analysis were used for statistical analysis. Notably, CD163+CD14+ cell frequency in MPE was remarkably higher than that in NMPE (P < 0.001). In a blinded validation study, a sensitivity of 78.9 % and a specificity of 100 % were obtained with CD163+CD14+ TAMs as a MPE biomarker. In total (n = 140), by using a cutoff level of 3.65 %, CD163+CD14+ cells had a sensitivity of 81.2 % and a specificity of 100 % for MPE diagnosis. Notably, MPE diagnosis by estimating CD163+CD14+ cells in pleural effusion could be obtained one week earlier than that obtained by cytological examination. CD163+CD14+ macrophages could be potentially used as an immune diagnostic marker for MPE and has better assay sensitivity than that of cytological analysis.
分类： 天文学 >> 天体物理学 提交时间： 2017-07-13
Shao, Lang
Zhang, Bin-Bin
Wang, Fu-Ri
Wu, Xue-Feng
Cheng, Ye-Hao
Zhang, Xi
Yu, Bang-Yao
Xi, Bao-Jia
Wang, Xue
Feng, Huan-Xue
Zhang, Meng
Xu, Dong
摘要： We carry out a systematical study of the spectral lag properties of 50 single-pulsed Gamma-Ray Bursts (GRBs) detected by Fermi/GBM. By dividing the light curves into multiple consecutive energy channels we provide a new measurement of the spectral lag which is independent on energy channel selections. We perform a detailed statistical study of our new measurements. We find two similar power-law energy dependencies of both the pulse arrival time and pulse width. Our new results on the power-law indices would favor the relativistic geometric effects for the origin of spectral lag. However, a complete theoretical framework that can fully account for the diverse energy dependencies of both arrival time and pulse width revealed in this work is still missing. We also study the spectral evolution behaviors of the GRB pulses. We find that the GRB pulse with negligible spectral lag would usually have a shorter pulse duration and would appear to have a ``hardness-intensity tracking'' (HIT) behavior and the GRB pulse with a significant spectral lag would usually have a longer pulse duration and would appear to have a ``hard-to-soft'' (HTS) behavior.
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