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Uncertainties of nuclear level density estimated using Bayesian neural networks

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Chinese Physics C 2024年第8期48卷 185-189页

作者： Xinyu Wang Ying Cui Yuan Tian Kai Zhao Yingxun Zhang China Institute of atomic energy Beijing 102413China China Nuclear Data Center China Institute of Atomic EnergyBeijing 102413China Guangxi Key Laboratory of Nuclear Physics and Technology Guangxi Normal UniversityGuilin 541004China

Nuclear level density(NLD)is a critical parameter for understanding nuclear reactions and the structure of atomic nuclei;however,accurate estimation of NLD is challenging owing to limitations inherent in both experimental measurements and theoretical *** paper presents a sophisticated approach using Bayesian neural networks(BNNs)to analyze NLD across a wide range of *** uniquely incorporates the assessment of model *** application of BNNs demonstrates remarkable success in accurately predicting NLD values when compared to recent experimental data,confirming the effectiveness of our *** reliability and predictive power of the BNN approach not only validates its current application but also encourages its integration into future analyses of nuclear reaction cross sections.

关键词： Bayesian neural network nuclear reaction nuclear level density

Imaging plate scanners calibration and the attenuation behavior of imaging plate signals

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Chinese Physics B 2024年第6期33卷 38-44页

作者：薄楠王乃彦 College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875China China Institute of atomic energy Beijing 102413China

Based on previously reported work, we propose a new method for calibrating image plate(IP) scanners, offering greater flexibility and convenience, which can be extended to the calibration tasks of various scanner models. This method was applied to calibrate the sensitivity of a GE Typhoon FLA 7000 scanner. Additionally, we performed a calibration of the spontaneous signal attenuation behavior for BAS-MS, BAS-SR, and BAS-TR type IPs under the 20±1℃ environmental conditions, and observed significant signal carrier diffusion behavior in BAS-MS IP. The calibration results lay a foundation for further research on the interaction between ultra-short, ultra-intense lasers and matter.

关键词： image plate scanner ultra-short ultra-intense lasers

Development of a multiplex polymerase chain reaction assay for detection of hepatitis C virus,hepatitis B virus,and human immunodeficiency virus 1

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World Journal of Virology 2024年第1期13卷 95-106页

作者： Waleed Abdelgaber Nemr Radwan K Nashwa Department of Radiation Microbiology National Center for Radiation Research and TechnologyEgyptian Atomic Energy AuthorityCairo 11371Egypt Department of Health Radiation Research National Center for Radiation Research and TechnologyEgyptian Atomic Energy AuthorityCairo 11371Egypt

BACKGROUND Hepatitis C virus(HCV),hepatitis B virus(HBV),and human immunodeficiency virus 1(HIV-1)are the most epidemic blood-borne viruses,posing threats to human health and causing economic losses to nations for combating the infection *** diagnostic methodologies that depend on the detection of viral nucleic acids are much more expensive,but they are more accurate than sero-logical *** To develop a rapid,cost-effective,and accurate diagnostic multiplex polymerase chain reaction(PCR)assay for simultaneous detection of HCV,HBV,and *** The design of the proposed PCR assay targets the amplification of a short conserved region featured with a distinguishable melting profile and electro-phoretic molecular weight inside each viral ***,this diagnostic method will be appropriate for application in both conventional(combined with electrophoresis)and real-time PCR *** in silico investigations were conducted to prove the capability of the approached PCR assay to detect variants of each ***,Egyptian isolates of each virus were subjected to the wet lab examination using the given diagnostic *** The in silico investigations confirmed that the PCR primers can match many viral variants in a multiplex PCR *** wet lab experiment proved the efficiency of the assay in distinguishing each viral type through high-resolution melting *** to related published assays,the proposed assay in the current study is more sensitive and competitive with many expensive PCR *** This study provides a simple,cost-effective,and sensitive diagnostic PCR assay facilitating the detection of the most epidemic blood-borne viruses;this makes the proposed assay promising to be substitutive for the mistakable and cheap serological-based assays.

关键词： Diagnosis Blood-borne viruses Multiplex polymerase chain reaction High-resolution melting

Numerical calculation of Z-scan measurements for nonlinear media with large phase shift

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Optoelectronics Letters 2024年第3期20卷 177-182页

作者： M.D.Zidan A.Allahham Department of Physics Atomic Energy Commission of SyriaP.O.Box 6091DamascusSyria

We have reported the characteristics of a Z-scan for the poly(azaneylylidene-acylene)(DAZA) polymer, as nonlinear medium with a large nonlinear phase shift using continuous-wave(CW) laser beam. It has been verified that the Fresnel diffraction model is applicable for analyses of Z-scan measurements with DAZA polymer at high laser power. It was found that Z-scan curves with peak-to-valley features appear as the applied light intensity increases in the case of a large nonlinear phase shift. The Z-scan experiments were carried out using a CW laser to verify the theoretical calculations in the case of a large nonlinear phase shift model. Our results show good agreements between the experimental data and the proposed theoretical models.

关键词： nonlinear phase media

Sensitivity impacts owing to the variations in the type of zero-range pairing forces on the fission properties using the density functional theory

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Nuclear Science and Techniques 2024年第3期35卷 198-207页

作者： Yang Su Ze-Yu Li Li-Le Liu Guo-Xiang Dong Xiao-Bao Wang Yong-Jing Chen China Nuclear Data Center China Institute of Atomic EnergyBeijing 102413China School of Science Huzhou UniversityHuzhou 313000China

Using the Skyrme density functional theory,potential energy surfaces of^(240)Pu with constraints on the axial quadrupole and octupole deformations(q_(20)and q_(30))were *** volume-like and surface-like pairing forces,as well as a combination of these two forces,were used for the Hartree–Fock–Bogoliubov *** in the least-energy fission path,fission barrier,pairing energy,total kinetic energy,scission line,and mass distribution of the fission fragments based on the different forms of the pairing forces were analyzed and *** fission dynamics were studied based on the timedependent generator coordinate method plus the Gaussian overlap *** results demonstrated a sensitivity of the mass and charge distributions of the fission fragments on the form of the pairing *** on the investigation of the neutron-induced fission of^(239)Pu,among the volume,mixed,and surface pairing forces,the mixed pairing force presented a good reproduction of the experimental data.

关键词： Nuclear fission Density functional theory Pairing force Potential energy surfaces Fission fragment distribution

Molecular dynamics study of primary radiation damage in TiVTa concentrated solid-solution alloy

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Chinese Physics B 2024年第3期33卷 530-535页

作者：赵永鹏豆艳坤贺新福曹晗王林枫邓辉球杨文 Reactor Engineering Technology Research Division China Institute of Atomic EnergyBeijing 102413China School of Physics and Electronics Hunan UniversityChangsha 410082China

The primary radiation damage in pure V and TiVTa concentrated solid-solution alloy(CSA)was studied using a molecular dynamics *** have performed displacement cascade simulations to explore the generation and evolution behavior of irradiation *** results demonstrate that the defect accumulation and agglomeration in TiVTa CSA are significantly suppressed compared to pure *** peak value of Frenkel pairs during cascade collisions in TiVTa CSA is much higher than that in pure V due to the lower formation energy of point ***,the longer lifetime of the thermal spike relaxation and slow energy dissipation capability of TiVTa CSA can facilitate the recombination of point *** defect agglomeration rate in TiVTa CSA is much lower due to the lower binding energy of interstitial clusters and reduced interstitial ***,the occurrence probability of dislocation loops in TiVTa CSA is lower than that in pure *** reduction in primary radiation damage may enhance the radiation resistance of TiVTa CSA,and the improved radiation tolerance is primarily attributed to the relaxation stage and long-term defect evolution rather than the ballistic *** results can provide fundamental insights into irradiation-induced defects evolution in refractory CSAs.

关键词： concentrated solid-solution alloy primary radiation damage molecular dynamics simulation

Nuclear decay database in fission product mass region

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Chinese Physics C 2024年第7期48卷 176-180页

作者：黄小龙杨东葛智刚王香涵刘洋阳金永利李剑 China Nuclear Data Center China Institute of Atomic EnergyBeijing 102413China College of Physics Jilin UniversityChangchun 130012China

Accurate and reliable nuclear decay databases are essential for fundamental and applied nuclear research ***,decay data are not usually as accurate as expected and need ***,a new Chinese nuclear decay database in the fission product mass region(A=66−172)based on several major national evaluated data libraries has been developed under joint efforts in the CNDC working group.A total of 2358 nuclides have been included in this decay *** main data formats,namely ENSDF and ENDF,have been *** the total meanβandγenergies,available data from total absorption gamma ray spectroscopy measurements have been *** some nuclides without experimental measurements,theoretically calculated values have been added.

关键词： nuclear decay data evaluation database fission product mass region

Direct Observation on H-Elimination Enhancement from C_(2)H_(4) through Non-Adiabatic Process by Femtosecond Laser Induced Coulomb Explosion

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Chinese Physics Letters 2024年第5期41卷 17-22页

作者：金无维王春成赵晓戈杨译章任殿相刘泽槿李孝开罗嗣佐丁大军 Institute of atomic and Molecular Physics Jilin UniversityChangchun 130012China Jilin Provincial Key Laboratory of Applied atomic and Molecular Spectroscopy Jilin UniversityChangchun 130012China

Ethylene, the simplest model of a carbon-carbon double bond system, is pivotal in numerous chemical and biological processes. By employing intense infrared laser pump-probe techniques alongside coincidence measurements, we investigate the ultrafast non-adiabatic dynamics involved in the breakage of carbon-carbon double bonds and hydrogen elimination in dissociation of ethylene. Our study entails analyzing the dynamic kinetic energy release spectra to assess three bond-breaking scenarios, movements of nuclei, and structural changes around the carbon atoms. This allows us to evaluate the relaxation dynamics and characteristics of various dissociative states. Notably, we observe a significant rise in the yield of fragments resulting from C–H bond breakage with the delay time extended, suggesting non-adiabatic coupling through conical intersections from C–C bond breakage as a probable cause.

关键词： pump Femto adiabatic

Benchmark experiment on slab^(238)U with D-T neutrons for validation of evaluated nuclear data

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Nuclear Science and Techniques 2024年第2期35卷 145-159页

作者： Yan-Yan Ding Yang-Bo Nie Yue Zhang Zhi-Jie Hu Qi Zhao Huan-Yu Zhang Kuo-Zhi Xu Shi-Yu Zhang Xin-Yi Pan Chang-Lin Lan Jie Ren Xi-Chao Ruan Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Institute of Fluid Physics China Academy of Engineering PhysicsMianyang 62100China

A benchmark experiment on^(238)U slab samples was conducted using a deuterium-tritium neutron source at the China Institute of atomic *** leakage neutron spectra within energy levels of 0.8-16 MeV at 60°and 120°were measured using the time-of-flight *** samples were prepared as rectangular slabs with a 30 cm square base and thicknesses of 3,6,and 9 *** leakage neutron spectra were also calculated using the MCNP-4C program based on the latest evaluated files of^(238)U evaluated neutron data from CENDL-3.2,ENDF/B-Ⅷ.0,JENDL-5.0,and *** on the comparison,the deficiencies and improvements in^(238)U evaluated nuclear data were *** results showed the following.(1)The calculated results for CENDL-3.2 significantly overestimated the measurements in the energy interval of elastic scattering at 60°and 120°.(2)The calculated results of CENDL-3.2 overestimated the measurements in the energy interval of inelastic scattering at 120°.(3)The calculated results for CENDL-3.2 significantly overestimated the measurements in the 3-8.5 MeV energy interval at 60°and 120°.(4)The calculated results with JENDL-5.0 were generally consistent with the measurement results.

关键词： Leakage neutron spectra Uranium D-T neutron source Evaluated nuclear data