期刊：
Reliability Engineering & System Safety,2025年256:110794 ISSN：0951-8320
通讯作者：
Zeng, WJ
作者机构：
[Li, Zheng; Chen, Chuqi; Li, Xiaoyu; Wang, Linna; Zeng, Wenjie; Zeng, WJ] Univ South China, Sch Nucl Sci & Technol, Hengyang City 421001, Peoples R China.
通讯机构：
[Zeng, WJ ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang City 421001, Peoples R China.
关键词：
Small pressurized water reactor;Nuclear power plant;Coordinated control system;Uncertainty quantification;Sensitivity analysis
摘要：
Parameter uncertainty is an inherent characteristic of control systems. To assess the impact of parameter uncertainty on the system, the dynamic performance assessment with uncertainty quantification and sensitivity analysis is proposed. The input sample set is obtained by Wilks' method and Latin hypercube sampling, then dynamic simulation and statistics are used to realize the uncertainty quantification of output parameters and the identification of key output parameters. The central composite design and second-order polynomial are used to build the agent model for the Sobol's method. Taking the small pressurized water reactor nuclear power plant as an example, a performance assessment platform of coordinated control system is developed through graphical user interface with fast load decrease conditions. The study shows that all the transient safety parameters except reactor core relative power and secondary-side outlet temperature of once-through steam generator (OTSG) satisfy the technical requirements, and the control system has a certain safety margin. Meanwhile, the adjustment time of reactor core relative power and secondary-side outlet temperature of OTSG is highly sensitive to primary-side flowrate of OTSG under the small range of variable load, and sensitive to the opening pressure of the steam dump valve under the large range of variable load.
Parameter uncertainty is an inherent characteristic of control systems. To assess the impact of parameter uncertainty on the system, the dynamic performance assessment with uncertainty quantification and sensitivity analysis is proposed. The input sample set is obtained by Wilks' method and Latin hypercube sampling, then dynamic simulation and statistics are used to realize the uncertainty quantification of output parameters and the identification of key output parameters. The central composite design and second-order polynomial are used to build the agent model for the Sobol's method. Taking the small pressurized water reactor nuclear power plant as an example, a performance assessment platform of coordinated control system is developed through graphical user interface with fast load decrease conditions. The study shows that all the transient safety parameters except reactor core relative power and secondary-side outlet temperature of once-through steam generator (OTSG) satisfy the technical requirements, and the control system has a certain safety margin. Meanwhile, the adjustment time of reactor core relative power and secondary-side outlet temperature of OTSG is highly sensitive to primary-side flowrate of OTSG under the small range of variable load, and sensitive to the opening pressure of the steam dump valve under the large range of variable load.
摘要：
In uranium(VI) (U(VI)) photoreduction, it is still a challenge to simultaneously degrade naturally coexisting organics and explore their impact on U(VI) photoreduction. Meanwhile, how to boost the separation and transport capability of photo-induced carriers is also a hot topic of current research. In this work, an ultrathin Bi 2 WO 6 /Bi 2 MoO 6 Z-type heterojunction was developed for the simultaneous treatment of U(VI) and its co-existing organics (tannic acid (TA)). Ultrathin interface engineering increased the contact area and shortened the transmission distance of photo-induced carriers. As a result, ultrathin Bi 2 WO 6 /Bi 2 MoO 6 exhibited highly efficient U(VI) removal rate (95.8 %) and TA degradation rate (97.2 %), which were much higher than those of bulk Bi 2 WO 6 /Bi 2 MoO 6 and single ultrathin Bi 2 WO 6 . In addition, the material possessed excellent stability and recyclability. Importantly, TA not only enhanced U(VI) removal by eliminating holes, but also favored U(VI) removal by serving as a bridge to the catalyst for U(VI) adsorption. Finally, a new mechanism was proposed.
In uranium(VI) (U(VI)) photoreduction, it is still a challenge to simultaneously degrade naturally coexisting organics and explore their impact on U(VI) photoreduction. Meanwhile, how to boost the separation and transport capability of photo-induced carriers is also a hot topic of current research. In this work, an ultrathin Bi 2 WO 6 /Bi 2 MoO 6 Z-type heterojunction was developed for the simultaneous treatment of U(VI) and its co-existing organics (tannic acid (TA)). Ultrathin interface engineering increased the contact area and shortened the transmission distance of photo-induced carriers. As a result, ultrathin Bi 2 WO 6 /Bi 2 MoO 6 exhibited highly efficient U(VI) removal rate (95.8 %) and TA degradation rate (97.2 %), which were much higher than those of bulk Bi 2 WO 6 /Bi 2 MoO 6 and single ultrathin Bi 2 WO 6 . In addition, the material possessed excellent stability and recyclability. Importantly, TA not only enhanced U(VI) removal by eliminating holes, but also favored U(VI) removal by serving as a bridge to the catalyst for U(VI) adsorption. Finally, a new mechanism was proposed.
通讯机构：
[Zeng, QY ; Xiao, Y ; Zhang, QS] U;Univ South China, Sch Resource & Environm & Safety Engn, Hengyang 421001, Peoples R China.;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
摘要：
Photocatalytic extraction of uranium from solution is one of the most promising technologies for uranium recovery. However, the presence of axial bonds between the two oxygen atoms in UO 2 2+ creates a high activation barrier for electron transfer, which hinders the reduction of UO 2 2+ , making it more challenging to reduce U( VI ) to U( IV ) with conventional photocatalysis. Herein, an ingenious strategy for the efficient removal of uranium from aqueous solutions, utilizing the photocatalytic hydrogen evolution reaction (HER) process, is proposed. In this process, a novel and highly stable bimetallic Co 9 Ni 1 -HOF was employed as a high HER performance photocatalyst, with an overpotential of 355 mV at 10 mA cm −2 . Benefiting from the excellent HER activity of Co 9 Ni 1 -HOF, efficient uranium removal (∼95.6%) within 60 min of illumination was achieved. The superior uranium removal performance could be ascribed to the enhanced HER performance due to the incorporation of Ni and the high affinity between U and OH*, resulting from the electron transfer between U and O and N, as confirmed by a series of experiments and density functional theory calculations. This work provides a new approach for the efficient removal of uranium using photocatalytic HER performance.
摘要：
Ruthenium removal from complex solutions (highly saline effluents, seawater) is a critical challenge. Herein, the sorption capacity of chitosan/SiO2 composite beads (Ch-Si) for ruthenium nitrosyl is increased three-fold after phosphoramidate grafting (DPA-Ch-Si, 1.6 mmol Ru g−1) at pH 5. Uptake kinetics and sorption isotherms are compared at pH0: 3, 5 and 10; playing with the mode of agitation (mechanical, MA, vs. ultrasonic treatment, UT). The sorbent maintains good sorption capacities at pH 3 and 10. Uptake kinetics modeled by pseudo-first order rate equation is boosted by functionalization. For Ch-Si, sorption isotherms are modeled by the Langmuir or Sips equations (depending on the pH), while for DPA-Ch-Si the best fits depend on pH, temperature and mode of agitation. Ruthenium sorption is spontaneous and endothermic for the two sorbents. For DPA-Ch-Si, the sorption capacity increases from 1.62 to 1.70 mmol Ru g−1 to 2.23–2.32 mmol Ru g−1 (T increasing from 21 to 50 °C). Nitric acid solution (0.3 M) reveals highly efficient for back extraction; ruthenium is completely released in <15 min. The functionalized sorbent can be reused for a minimum of 10 cycles, with limited loss in performance. Phosphoramidation improves sorption selectivity for the treatment of equimolar multicomponent solutions (Na, Ca, Mg, Fe, Al, U, and Nd). The effect of pH on sorption selectivity is evaluated in simple multi-metal solutions and complex environment. In seawater, the selective recovery of ruthenium is favored at pH close to 10. These tests confirm the promising perspectives offered for ruthenium removal from complex environments. Physicochemical characterizations of the sorbent (and their modes of interaction with ruthenium nitrosyl) included SEM, BET, TGA, FTIR, XPS, and elemental analyses.
Ruthenium removal from complex solutions (highly saline effluents, seawater) is a critical challenge. Herein, the sorption capacity of chitosan/SiO2 composite beads (Ch-Si) for ruthenium nitrosyl is increased three-fold after phosphoramidate grafting (DPA-Ch-Si, 1.6 mmol Ru g−1) at pH 5. Uptake kinetics and sorption isotherms are compared at pH0: 3, 5 and 10; playing with the mode of agitation (mechanical, MA, vs. ultrasonic treatment, UT). The sorbent maintains good sorption capacities at pH 3 and 10. Uptake kinetics modeled by pseudo-first order rate equation is boosted by functionalization. For Ch-Si, sorption isotherms are modeled by the Langmuir or Sips equations (depending on the pH), while for DPA-Ch-Si the best fits depend on pH, temperature and mode of agitation. Ruthenium sorption is spontaneous and endothermic for the two sorbents. For DPA-Ch-Si, the sorption capacity increases from 1.62 to 1.70 mmol Ru g−1 to 2.23–2.32 mmol Ru g−1 (T increasing from 21 to 50 °C). Nitric acid solution (0.3 M) reveals highly efficient for back extraction; ruthenium is completely released in <15 min. The functionalized sorbent can be reused for a minimum of 10 cycles, with limited loss in performance. Phosphoramidation improves sorption selectivity for the treatment of equimolar multicomponent solutions (Na, Ca, Mg, Fe, Al, U, and Nd). The effect of pH on sorption selectivity is evaluated in simple multi-metal solutions and complex environment. In seawater, the selective recovery of ruthenium is favored at pH close to 10. These tests confirm the promising perspectives offered for ruthenium removal from complex environments. Physicochemical characterizations of the sorbent (and their modes of interaction with ruthenium nitrosyl) included SEM, BET, TGA, FTIR, XPS, and elemental analyses.
摘要：
Multi-component carbide (MCC) ceramics are promising structural materials in advanced nuclear reactors. However, their behavior upon irradiation, particularly the interaction between vacancy defects and helium atoms, remains inadequately understood. In this study, two MCC ceramics, (NbTaZr)C 3 and (NbTaTiZr)C 4 were irradiated with 50-keV He-ion at room temperature. The microstructures were characterized using transmission electron microscopy, and the vacancy-type defects were investigated using positron annihilation spectroscopy and first-principles calculations. Before irradiation, numerous intrinsic vacancy defects were detected in pristine MCC ceramics. After irradiation at low dose (1 ×10 16 ions/cm 2 ), a defect-filling mechanism was found to dominate, and the intrinsic vacancy defects can effectively trap helium atoms to form helium-vacancy complexes. Under higher irradiation fluences of 5 × 10 16 ions/cm 2 and 1 × 10 17 ions/cm 2 , the collision cascade mechanism was found to dominate, and high-energy helium ion implantation caused collision cascades that generated numerous vacancy defects. These findings could provide valuable insights into the evolution of vacancy-type defects and the growth of helium bubbles in MCC ceramics.
Multi-component carbide (MCC) ceramics are promising structural materials in advanced nuclear reactors. However, their behavior upon irradiation, particularly the interaction between vacancy defects and helium atoms, remains inadequately understood. In this study, two MCC ceramics, (NbTaZr)C 3 and (NbTaTiZr)C 4 were irradiated with 50-keV He-ion at room temperature. The microstructures were characterized using transmission electron microscopy, and the vacancy-type defects were investigated using positron annihilation spectroscopy and first-principles calculations. Before irradiation, numerous intrinsic vacancy defects were detected in pristine MCC ceramics. After irradiation at low dose (1 ×10 16 ions/cm 2 ), a defect-filling mechanism was found to dominate, and the intrinsic vacancy defects can effectively trap helium atoms to form helium-vacancy complexes. Under higher irradiation fluences of 5 × 10 16 ions/cm 2 and 1 × 10 17 ions/cm 2 , the collision cascade mechanism was found to dominate, and high-energy helium ion implantation caused collision cascades that generated numerous vacancy defects. These findings could provide valuable insights into the evolution of vacancy-type defects and the growth of helium bubbles in MCC ceramics.
通讯机构：
[Wang, F ] B;Beijing Inst Technol, Sch Phys, Beijing 100081, Peoples R China.
摘要：
We conducted a study on the electron stopping power of protons in aluminum at finite electron temperatures, utilizing time-dependent density functional theory nonadiabatically coupled with molecular dynamics. Our investigation focused on protons with initial velocities ranging from 0.1 to 1.0 a.u., providing a wealth of detailed information on the electronic states involved in the stopping process, with exceptional spatial and temporal resolution. Our results show that the electron temperature can significantly effect the electron stopping power. A quantum-blocking mechanism based on a physical picture of electronic transitions in energy levels has been proposed for explaining the phenomenon of electron stopping power decreasing with the increase of target electron temperature.
期刊：
Chemical Engineering Journal,2025年505:159469 ISSN：1385-8947
通讯作者：
Guibal, E;Hamza, MF
作者机构：
[Salih, Khalid A. M.; Zhou, Kanggen] Cent South Univ, Sch Met & Environm, Changsha 410083, Peoples R China.;[Guibal, Eric; Guibal, E] IMT Mines Ales, Polymers Compos & Hybrids PCH, Ales, France.;[Basiony, Ebtesam A.; Nassar, Lobna A.; Abdel-Rahman, Adel A. -H.] Menoufia Univ, Fac Sci, Chem Dept, Shibin Al Kawm 32511, Egypt.;[Ning, Shunyan; Wei, Yuezhou; Hamza, Mohammed F.; Hamza, MF] Univ South China, Sch Nucl Sci & Technol, Heng Yang 421001, Peoples R China.;[Wei, Yuezhou] Shanghai Jiao Tong Univ, Sch Nucl Sci & Engn, Shanghai, Peoples R China.
通讯机构：
[Hamza, MF ] U;[Guibal, E ] I;IMT Mines Ales, Polymers Compos & Hybrids PCH, Ales, France.;Univ South China, Sch Nucl Sci & Technol, Heng Yang 421001, Peoples R China.
关键词：
Carbamoylacetamide derivative grafted-chitosan;Enhancing U(VI) sorption by ion imprinting: improved uptake kinetics and selectivity;Comparative studies of ion-imprinting and non-imprinting sorbents;Remarkable stability after 10 cycles of sorption and desorption;Efficient uranium recovery from acidic ore leachate
摘要：
Uranium recovery from complex effluents requires the combination of different processes including metal sorption from low-concentration solutions containing several competitor metal ions. The design of efficient sorbents (BTC/CH(s), 2-(benzo[d]thiazol-2-yl)-N-carbamoyl acetamide grafted chitosan) that combine both high sorption capacity and high selectivity was achieved by adopting a dual strategy: (a) selecting efficient functional groups (amine, amide, thioester, and hydroxyl groups, in BTC/CH sorbents), and (b) adapting the arrangement of reactive groups appropriately to fit the specific shape of the complexes (ion-imprinting IP vs. non-ion-imprinted NIP materials). This dual strategy was applied to design a chitosan-based sorbent with high sorption capacity (≈1.5 mmol U g −1 ), fast uptake (equilibrium: 15–20 min), remarkable stability (limited loss of performances after 10 reuse cycles), and strong selectivity (tested on both equimolar multi-component solutions and pre-treated acid leachate), at moderately acidic pH (i.e., 4). Ion-templating strategy effectively improved selectivity by 5–10-folds. Uptake kinetics was fitted by the pseudo-first order rate equation, while the sorption isotherms were finely simulated by the Temkin equation. The sorption was exothermic, spontaneous, and the ion-templating allowed reaching more organized structure. The sorbent was highly selective against base metals, alkali and alkali-earth metals, but less efficient for the separation from thorium or rare-earth elements. The sorbent was successfully used for the recovery of residual uranyl from acidic leachates pre-treated with resins (Amberlite IRA-400 and DOWEX 50, for the recovery of U and rare-earth elements, respectively) and precipitation step (removal of Al(III)/Fe(III) at pH 4). The sorbents were characterized by elemental analysis, FTIR and XPS spectroscopy for analyzing the chemical structure of the materials and identifying their interactions with U(VI). Textural properties and pHpzc values were analyzed for supporting sorption behaviors.
Uranium recovery from complex effluents requires the combination of different processes including metal sorption from low-concentration solutions containing several competitor metal ions. The design of efficient sorbents (BTC/CH(s), 2-(benzo[d]thiazol-2-yl)-N-carbamoyl acetamide grafted chitosan) that combine both high sorption capacity and high selectivity was achieved by adopting a dual strategy: (a) selecting efficient functional groups (amine, amide, thioester, and hydroxyl groups, in BTC/CH sorbents), and (b) adapting the arrangement of reactive groups appropriately to fit the specific shape of the complexes (ion-imprinting IP vs. non-ion-imprinted NIP materials). This dual strategy was applied to design a chitosan-based sorbent with high sorption capacity (≈1.5 mmol U g −1 ), fast uptake (equilibrium: 15–20 min), remarkable stability (limited loss of performances after 10 reuse cycles), and strong selectivity (tested on both equimolar multi-component solutions and pre-treated acid leachate), at moderately acidic pH (i.e., 4). Ion-templating strategy effectively improved selectivity by 5–10-folds. Uptake kinetics was fitted by the pseudo-first order rate equation, while the sorption isotherms were finely simulated by the Temkin equation. The sorption was exothermic, spontaneous, and the ion-templating allowed reaching more organized structure. The sorbent was highly selective against base metals, alkali and alkali-earth metals, but less efficient for the separation from thorium or rare-earth elements. The sorbent was successfully used for the recovery of residual uranyl from acidic leachates pre-treated with resins (Amberlite IRA-400 and DOWEX 50, for the recovery of U and rare-earth elements, respectively) and precipitation step (removal of Al(III)/Fe(III) at pH 4). The sorbents were characterized by elemental analysis, FTIR and XPS spectroscopy for analyzing the chemical structure of the materials and identifying their interactions with U(VI). Textural properties and pHpzc values were analyzed for supporting sorption behaviors.
期刊：
Journal of High Energy Physics,2025年2025(2):1-27 ISSN：1029-8479
通讯作者：
Chen, X
作者机构：
[Chen, Xun; Chen, X] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Chen, Xun; Chen, X] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Huang, Mei] Univ Chinese Acad Sci, Sch Nucl Sci & Technol, Beijing 100049, Peoples R China.
通讯机构：
[Chen, X ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.
关键词：
Gauge-Gravity Correspondence;Phase Diagram or Equation of State;Quark-Gluon Plasma
摘要：
QCD phase diagram in the T - mu plane and the equation of state for pure gluon, 2-flavor, 2+1-flavor systems, and 2+1+1-flavor systems have been investigated using the Einstein-Maxwell-Dilaton (EMD) framework at finite temperature and chemical potential. By inputting lattice QCD data for the equation of state and baryon number susceptibility at zero chemical potential into holographic model, all the parameters can be determined with the aid of machine learning algorithms. Our findings indicate that the deconfinement phase transition is of first order for the pure gluon system with critical temperature Tc = 0.265 GeV at vanishing chemical potential. The phase transition for the 2-flavor, 2+1-flavor systems, and 2+1+1-flavor systems are crossover at vanishing chemical potential and first-order at high chemical potential, and the critical endpoint (CEP) in the T - mu plane locates at (mu Bc\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mu}_B<^>c $$\end{document} = 0.46 GeV, Tc= 0.147 GeV), (mu Bc\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mu}_B<^>c $$\end{document} = 0.74 GeV, Tc = 0.094 GeV), and (mu Bc\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ {\mu}_B<^>c $$\end{document} = 0.87 GeV, Tc = 0.108 GeV), respectively. Additionally, the thermodynamic quantities of the system for different flavors at finite chemical potential are presented in this paper. It is observed that the difference between the 2+1-flavor and 2+1+1-flavor systems is invisible at vanishing chemical potential and low temperature. The location of CEP for 2+1+1-flavor system deviates explicitly from that of the 2+1-flavor system with the increase of chemical potential. Both 2+1-flavor and 2+1+1-flavor systems differ significantly from the 2-flavor system. Moreover, at zero temperature, the critical chemical potential is found to be mu B = 1.1 GeV, 1.6 GeV, 1.9 GeV for the 2-flavor, 2+1-flavor and 2+1+1-flavor systems, respectively.
摘要：
FLASH radiotherapy (FLASH-RT) has emerged as a significant area of research in the field of radiotherapy in recent years. This innovative technology delivers ultra-high dose rate radiation in a very short time, effectively damaging tumor cells while minimizing the impact on surrounding normal tissues. Currently, the beams that have been proven to achieve the FLASH effect include electrons, protons, and photons. X-ray FLASH-RT exhibits enhanced penetration capabilities and superior cost-effectiveness. However, the detectors currently used for X-ray FLASH-RT dose rate measurement generally exhibit saturation effects and a limited dose linear response range. In this review, we provide a comprehensive summary of the primary devices used to generate ultra-high dose rate X-rays. Additionally, we classify and describe the reported detectors for monitoring the high-dose rate in X-ray FLASH-RT according to three main types: gaseous detectors, scintillators, and semiconductors. This offers researchers valuable insights and a solid reference for selecting and optimizing detectors to achieve more precise and reliable high-dose rate X-ray measurements in X-ray FLASH-RT. Additionally, it provides significant support for the further development and clinical implementation of FLASH-RT technology.
摘要：
The design of complex reactor shielding structures requires consideration of neutron and photon radiation levels in various regions, as well as trade-offs in weight, volume, and cost, leading to a substantial increase in shielding calculation parameters and optimization objectives. This study introduces a high-dimensional multi-objective shielding optimization method based on a multi-parameter shielding calculation surrogate model, with significant improvements to the FCNN-NSGAIII shielding optimization method which integrates a neural network with a genetic algorithm. For the optimization of complex reactor shielding structures under diverse source item energy spectra, the multi-parameter surrogate model achieves a prediction error reduction of an order of magnitude to 3.65% compared to traditional neural networks. Furthermore, the k_NSGAIII optimization algorithm, enhanced with a knee-point strategy, demonstrates a greater relative set coverage indicator than the NSGAIII algorithm, indicating its ability to identify superior shielding design schemes.
The design of complex reactor shielding structures requires consideration of neutron and photon radiation levels in various regions, as well as trade-offs in weight, volume, and cost, leading to a substantial increase in shielding calculation parameters and optimization objectives. This study introduces a high-dimensional multi-objective shielding optimization method based on a multi-parameter shielding calculation surrogate model, with significant improvements to the FCNN-NSGAIII shielding optimization method which integrates a neural network with a genetic algorithm. For the optimization of complex reactor shielding structures under diverse source item energy spectra, the multi-parameter surrogate model achieves a prediction error reduction of an order of magnitude to 3.65% compared to traditional neural networks. Furthermore, the k_NSGAIII optimization algorithm, enhanced with a knee-point strategy, demonstrates a greater relative set coverage indicator than the NSGAIII algorithm, indicating its ability to identify superior shielding design schemes.
摘要：
Intelligent fault diagnosis (IFD) plays a crucial role in reducing maintenance costs and enhancing the reliability of safety-critical energy systems (SCESs). In recent years, deep learning-based IFD methods have achieved high fault diagnosis accuracy extracting implicit higher-order correlations between features. However, the excessive long training time of deep learning models conflicts with the requirements of real-time analysis for IFD, hindering their further application in practical industrial environments. To address the aforementioned challenge, this paper proposes an innovative IFD method for SCES that combines the particle swarm optimization (PSO) algorithm and the ensemble broad learning system (EBLS). Specifically, the broad learning system (BLS), known for its low time complexity and high classification accuracy, is adopted as an alternative to deep learning for fault diagnosis in SCES. Furthermore, EBLS is designed to enhance model stability and classification accuracy with high-dimensional small samples by incorporating the random forest (RF) algorithm and an ensemble strategy into the traditional BLS framework. In order to reduce the computational cost of the EBLS, which is constrained by the selection of its hyperparameters, the PSO algorithm is employed to optimize the hyperparameters of the EBLS. Finally, the model is validated through simulated data from a complex nuclear power plant (NPP). Numerical experiments reveal that the proposed method significantly improved the diagnostic efficiency while maintaining high accuracy. In summary, the proposed approach shows great promise for boosting the capabilities of the IFD models for SCES.
作者机构：
[Chen, YD; Chen, Yidian] Hangzhou Normal Univ, Sch Phys, Hangzhou 311121, Peoples R China.;[Chen, Xun] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Chen, Xun] Cent China Normal Univ, Key Lab Quark & Lepton Phys MOE, Wuhan 430079, Peoples R China.;[Li, Danning] Jinan Univ, Dept Phys, Guangzhou 510632, Peoples R China.;[Li, Danning] Jinan Univ, Siyuan Lab, Guangzhou 510632, Peoples R China.
通讯机构：
[Chen, YD ] H;Hangzhou Normal Univ, Sch Phys, Hangzhou 311121, Peoples R China.
摘要：
We investigate the effects of rotation on deconfinement and chiral phase transitions in the framework of the dynamical holographic QCD model. Instead of transforming to the rotating system by Lorentz boost, we construct an anisotropic gravitational background by incorporating the rotating boundary current. We first investigate the pure gluon system under rotation to extract deconfinement phase transition from the Polyakov loop then add two-flavor probe for chiral restoration phase transition from the chiral condensate. It is observed that at low chemical potentials, the deconfinement phase transition of pure gluon system is of first order and the chiral phase transition of a two-flavor system is of crossover. Both the critical temperatures of deconfinement and chiral phase transitions decrease/increase with imaginary/real angular velocity (Omega(I)/Omega) as T/T-c similar to 1 - C-2 Omega(2)(I) and T/T-c similar to 1 + C-2 Omega(2), which is consistent with lattice QCD results. In the temperature-chemical potential T - mu phase diagram, the critical end point moves toward regions of higher temperature and chemical potential with real angular velocity.
摘要：
The multiple nuclides identification algorithm with low consumption and strong robustness is crucial for rapid radioactive source searching. This study investigates the design of a low-consumption multiple nuclides identification algorithm for portable gamma spectrometers. First, the gamma spectra of 12 target nuclides (including the background case) were measured to create training datasets. The characteristic energies, obtained through energy calibration and full-energy peak addresses, are utilized as input features for a neural network. A large number of single- and multiple-nuclide training datasets are generated using random combinations and small-range drifting. Subsequently, a multi-label classification neural network based on a binary cross-entropy loss function is applied to export the existence probability of certain nuclides. The designed algorithm effectively reduces the computation time and storage space required by the neural network and has been successfully implemented in a portable gamma spectrometer with a running time of
$$t_\text {r}<{2\,\textrm{s}}$$
. Results show that, in both validation and actual tests, the identification accuracy of the designed algorithm reaches 94.8%, for gamma spectra with a dose rate of
$$d\approx {0.5\,\mathrm{\upmu Sv/h}}$$
and a measurement time
$$t_\text {m}={60\,\textrm{s}}$$
. This improves the ability to perform rapid on-site nuclide identification at important sites.
摘要：
In recent years, the development of new types of nuclear reactors, such as transportable, marine, and space reactors, has presented new challenges for the optimization of reactor radiation-shielding design. Shielding structures typically need to be lightweight, miniaturized, and radiation-protected, which is a multi-parameter and multi-objective optimization problem. The conventional multi-objective (two or three objectives) optimization method for radiation-shielding design exhibits limitations for a number of optimization objectives and variable parameters, as well as a deficiency in achieving a global optimal solution, thereby failing to meet the requirements of shielding optimization for newly developed reactors. In this study, genetic and artificial bee-colony algorithms are combined with a reference-point-selection strategy and applied to the many-objective (having four or more objectives) optimal design of reactor radiation shielding. To validate the reliability of the methods, an optimization simulation is conducted on three-dimensional shielding structures and another complicated shielding-optimization problem. The numerical results demonstrate that the proposed algorithms outperform conventional shielding-design methods in terms of optimization performance, and they exhibit their reliability in practical engineering problems. The many-objective optimization algorithms developed in this study are proven to efficiently and consistently search for Pareto-front shielding schemes. Therefore, the algorithms proposed in this study offer novel insights into improving the shielding-design performance and shielding quality of new reactor types.
摘要：
We present new data on the
$$^{63}$$
Cu(
$$\gamma$$
, n) cross-section studied using a quasi-monochromatic and energy-tunable
$$\gamma$$
beam produced at the Shanghai Laser Electron Gamma Source to resolve the long-standing discrepancy between existing measurements and evaluations of this cross-section. Using an unfolding iteration method,
$$^{63}$$
Cu(
$$\gamma$$
, n) data were obtained with an uncertainty of less than 4%, and the inconsistencies between the available experimental data were discussed. The
$$\gamma$$
-ray strength function of
$$^{63}$$
Cu(
$$\gamma$$
, n) was successfully extracted as an experimental constraint. We further calculated the cross-section of the radiative neutron capture reaction
$$^{62}$$
Cu(n,
$$\gamma$$
) using the TALYS code. Our calculation method enables the extraction of (n,
$$\gamma$$
) cross-sections for unstable nuclides.
通讯机构：
[Zhang, S ; Chen, LW] A;[Chen, LW ] C;[Li, XX ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;Adv Energy Sci & Technol Guangdong Lab, Huizhou 516000, Peoples R China.
关键词：
Classical trajectory Monte Carlo;Heavy ion-water molecule collision;Inelastic cross sections
摘要：
Inelastic collisions are the dominant cause of energy loss in radiotherapy. In the energy range around the Bragg peak, single ionization (SI) and single-electron capture (SC) are the primary inelastic collisions that lead to energy loss. This study employs the classical trajectory Monte Carlo method to study the SI and SC processes of H
$$_{2}$$
O molecules using He
$$^{2+}$$
and C
$$^{6+}$$
projectiles in the energy range of 10 keV/u to 10 MeV/u. The total cross sections, single differential cross sections, impact parameter dependence of SI and SC, and fragmentation cross sections were investigated. Results illustrate that the cross section for SI is the highest when the projectile energy is close to the Bragg peak energy. When the projectile energy is below the Bragg peak energy, the ionized electrons in the forward direction dominate, and the removal of electrons can be associated with large impact parameters. As the projectile energy increases, the emission angle of the electrons gradually transitions from small angles (
$$0^{\circ} \sim 30^{\circ}$$
) to large angles (
$$60^{\circ} \sim 120^{\circ}$$
), and the removal of electrons is associated with small impact parameters. The energy distributions of the ionized electron are similar when the projectile energy is equal to, below or above the Bragg peak energy. The fragmentation cross sections after SI and SC in the energy range around the Bragg peak were also estimated.
期刊：
Nuclear Engineering and Design,2025年433:113872 ISSN：0029-5493
通讯作者：
Liu, HL
作者机构：
[Liu, Hongliang; Ouyang, Zigen; Liu, HL; Liu, Wangheng] Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.;[Zeng, Wenjie] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Liu, Hua] Univ South China, Sch Elect Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Liu, HL ] U;Univ South China, Sch Math & Phys, Hengyang 421001, Peoples R China.
关键词：
Adaptive learning observer;Radial basis function neural networks;Fixed-time fault-tolerant control;Control rod drive mechanism faults;Load following for modular high-temperature;gas-cooled reactor
摘要：
Load following of the Modular High-Temperature Gas-Cooled Reactor (MHTGR) under Control Rod Drive Mechanism (CRDM) faults and disturbances remains a major challenge. This paper focuses on proposing a fixed-time fault-tolerant control method for this issue without considering the sensitivities associated with parameter setting. Firstly, to reconstruct some unmeasurable states of the MHTGR and the values of CRDM faults, an adaptive learning observer is established. Based on the learning characteristic of Radial Basis Function Neural Networks (RBFNN), the lumped uncertainties can be approximated. And then a fixed-time fault-tolerant controller is developed to ensure that the actual load output of the MHTGR actually tracks the expected output power within a fixed time, which can be determined through the system and controller parameters. Finally, simulations under two operational conditions demonstrate the control method is effective and feasible to the MHTGR system under disturbance and CRDM faults.
Load following of the Modular High-Temperature Gas-Cooled Reactor (MHTGR) under Control Rod Drive Mechanism (CRDM) faults and disturbances remains a major challenge. This paper focuses on proposing a fixed-time fault-tolerant control method for this issue without considering the sensitivities associated with parameter setting. Firstly, to reconstruct some unmeasurable states of the MHTGR and the values of CRDM faults, an adaptive learning observer is established. Based on the learning characteristic of Radial Basis Function Neural Networks (RBFNN), the lumped uncertainties can be approximated. And then a fixed-time fault-tolerant controller is developed to ensure that the actual load output of the MHTGR actually tracks the expected output power within a fixed time, which can be determined through the system and controller parameters. Finally, simulations under two operational conditions demonstrate the control method is effective and feasible to the MHTGR system under disturbance and CRDM faults.
摘要：
This study, adhering to the Chinese standard GB/T 34008-2017, introduces a penalty-function-based particle swarm optimization algorithm and proposes an innovative approach for optimizing the aggregate mix ratio in radiation-shielding concrete. Utilizing barite, magnetite, and hematite as aggregates, the proposed optimization method yielded optimal mix ratios tailored for shielding 4.5 and 10 MeV neutrons while achieving target compressive strengths of 35 and 40 MPa. Geant4 simulations and experimental validations confirm that the optimized concrete offers robust neutron and gamma-ray shielding properties. Compared to conventional concrete, it achieves a 20.89% reduction in maximum neutron absorption dose and enhances the gamma-ray linear attenuation coefficient by up to 43.17%. The developed optimization method offers valuable guidance for shielding design in nuclear technology application laboratories.
通讯机构：
[Xia, LS ; Xiao, Y] U;[Yu, H ] C;Changchun Univ Sci & Technol, Sch Chem & Environm Engn, Changchun 130000, Peoples R China.;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
关键词：
ZnO nanoflower;NOx gas sensing;Crystal facet;Grain size;Debye length
摘要：
Multilayer ZnO nanoflowers constructed by many nanograins with highly exposed {0001} facet have been prepared. The grain size and exposed {0001} facet is adjusted by hydrothermal condition and citrate-assisted steric hindrance, respectively. Subsequently, the gas sensing performances of the as-prepared ZnO sensors with various hydrothermal temperatures and times were investigated. The detailedly sensing experiments demonstrated that when the hydrothermal temperature and time are 120 °C and 9h, respectively, the obtained ZnO nanoflower sensor (ZnO-120-9) possesses optimal response of 80.3 towards 100 ppm NO x gas concentration at 180 °C. Meanwhile, ZnO-120-9 exhibits excellent selectivity, rapid response and recovery time, and also shows an obvious response signal at 0.5 ppm NO x exposure, which manifests that the lower concentration detection is also attainable. The superior performance of ZnO-120-9 towards NO x is due to the highly exposed {0001} facet and the size comparable to Debye length. As a result, such structure is conducive to the adsorption of more oxygen species and significant reduction of resistance, and they improve the sensitivity of a sensor.
Multilayer ZnO nanoflowers constructed by many nanograins with highly exposed {0001} facet have been prepared. The grain size and exposed {0001} facet is adjusted by hydrothermal condition and citrate-assisted steric hindrance, respectively. Subsequently, the gas sensing performances of the as-prepared ZnO sensors with various hydrothermal temperatures and times were investigated. The detailedly sensing experiments demonstrated that when the hydrothermal temperature and time are 120 °C and 9h, respectively, the obtained ZnO nanoflower sensor (ZnO-120-9) possesses optimal response of 80.3 towards 100 ppm NO x gas concentration at 180 °C. Meanwhile, ZnO-120-9 exhibits excellent selectivity, rapid response and recovery time, and also shows an obvious response signal at 0.5 ppm NO x exposure, which manifests that the lower concentration detection is also attainable. The superior performance of ZnO-120-9 towards NO x is due to the highly exposed {0001} facet and the size comparable to Debye length. As a result, such structure is conducive to the adsorption of more oxygen species and significant reduction of resistance, and they improve the sensitivity of a sensor.
摘要：
Background and purpose The image quality of single-energy CT (SECT) limited the accuracy of automatic segmentation. Dual-energy CT (DECT) may potentially improve automatic segmentation yet the performance and strategy have not been investigated thoroughly. Based on DECT-generated virtual monochromatic images (VMIs), this study proposed a novel deep learning model (MIAU-Net) and evaluated the segmentation performance on the head organs-at-risk (OARs).
The image quality of single-energy CT (SECT) limited the accuracy of automatic segmentation. Dual-energy CT (DECT) may potentially improve automatic segmentation yet the performance and strategy have not been investigated thoroughly. Based on DECT-generated virtual monochromatic images (VMIs), this study proposed a novel deep learning model (MIAU-Net) and evaluated the segmentation performance on the head organs-at-risk (OARs).
Methods and Materials The VMIs from 40 keV to 190 keV were retrospectively generated at intervals of 10 keV using the DECT of 46 patients. Images with expert delineation were used for training, validation, and testing MIAU-Net for automatic segmentation. The performance of MIAU-Net was compared with the existing U-Net, Attention-UNet, nnU-Net and TransFuse methods based on Dice Similarity Coefficient (DSC). Correlation analysis was performed to evaluate and optimize the impact of different virtual energies on the accuracy of segmentation.
The VMIs from 40 keV to 190 keV were retrospectively generated at intervals of 10 keV using the DECT of 46 patients. Images with expert delineation were used for training, validation, and testing MIAU-Net for automatic segmentation. The performance of MIAU-Net was compared with the existing U-Net, Attention-UNet, nnU-Net and TransFuse methods based on Dice Similarity Coefficient (DSC). Correlation analysis was performed to evaluate and optimize the impact of different virtual energies on the accuracy of segmentation.
Results Using MIAU-Net, average DSCs across all virtual energy levels were 93.78 %, 81.75 %, 84.46 %, 92.85 %, 94.40 %, and 84.75 % for the brain stem, optic chiasm, lens, mandible, eyes, and optic nerves, respectively, higher than the previous publications using SECT. MIAU-Net achieved the highest average DSC (88.84 %) and the lowest parameters (14.54 M) in all tested models. The results suggested that 60 keV-80 keV is the optimal VMI energy level for soft tissue delineation, while 100 keV is optimal for skeleton segmentation.
Using MIAU-Net, average DSCs across all virtual energy levels were 93.78 %, 81.75 %, 84.46 %, 92.85 %, 94.40 %, and 84.75 % for the brain stem, optic chiasm, lens, mandible, eyes, and optic nerves, respectively, higher than the previous publications using SECT. MIAU-Net achieved the highest average DSC (88.84 %) and the lowest parameters (14.54 M) in all tested models. The results suggested that 60 keV-80 keV is the optimal VMI energy level for soft tissue delineation, while 100 keV is optimal for skeleton segmentation.
Conclusions This work proposed and validated a novel deep learning model for automatic segmentation based on DECT, suggesting potential advantages and OAR-specific optimal energy of using VMIs for automatic delineation.
This work proposed and validated a novel deep learning model for automatic segmentation based on DECT, suggesting potential advantages and OAR-specific optimal energy of using VMIs for automatic delineation.
