摘要:
Here, we report the generation of MeV alpha-particles from H-<sup>11</sup>B fusion initiated by laser-accelerated boron ions. Boron ions with maximum energy of 6 MeV and fluence of 10<sup>9</sup>/MeV/sr@5 MeV were generated from 60 nm-thick self-supporting boron nanofoils irradiated by 1 J femtosecond pulses at an intensity of 10<sup>19</sup> W/cm<sup>2</sup>. By bombarding secondary hydrogenous targets with the boron ions, 3 × 10<sup>5</sup>/sr alpha-particles from H-<sup>11</sup>B fusion were registered, which is consistent with the theoretical yield calculated from the measured boron energy spectra. Our results demonstrated an alternative way toward ultrashort MeV alpha-particle sources employing compact femtosecond lasers. The ion acceleration and product measurement scheme are referential for the studies on the ion stopping power and cross section of the H-<sup>11</sup>B reaction in solid or plasma.
期刊:
Journal of Colloid and Interface Science,2022年625:859-870 ISSN:0021-9797
通讯作者:
Zeng, Deqian
作者机构:
[Zeng, Deqian; Fujita, Toyohisa; He, Xianglong; Liu, Yimin; Chen, Qian; Gao, Runchen] Guangxi Univ, Sch Resources Environm & Mat, Guangxi Key Lab Proc Nonferrous Met & Featured Mat, Nanning 530004, Peoples R China.;[Yang, Jingren] Shanghai Acad Environm Sci, State Environm Protect Key Lab Environm Hlth Impac, Shanghai 200233, Peoples R China.;[Wei, Yuezhou] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构:
[Zeng, Deqian] G;Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China. Electronic address:
摘要:
Incorporating 2D transition-metal phosphides into visible-light-driven semiconductors is fascinating for advancing novel photocatalysts. In this paper, porous Co(x)P nanosheets prepared by phosphating Co(OH)(2) nanosheets are coupled with Mn(0.35)Cd(0.65)S nanoparticles for significantly boosted photocatalytic H(2) evolution performance. The optimal Co(x)P/Mn(0.35)Cd(0.65)S hybrids show an excellent visible-light H(2) production rate of 7188.9μmolg(-1)h(-1) upon visible light with an apparent quantum yield (AQY) of 18.9% at 420nm. The H(2) production rate of the 5% Co(x)P/Mn(0.35)Cd(0.65)S sample is about 257 times bare CdS and even 18 times higher than pristine Mn(0.35)Cd(0.65)S. This dramatic photocatalytic H(2) generation activity is mainly ascribed to the efficient charge transfer and abundant active sites by introducing the porous Co(x)P nanosheets. The photocatalytic mechanism of the Co(x)P/Mn(0.35)Cd(0.65)S composites is investigated by the photoluminescence (PL), time-resolved photoluminescence (TRPL), electrochemical, and photoelectrochemical (PEC) tests. This work presents a viable strategy to design a 2D/0D hybrid system containing porous cobalt phosphides nanosheets and MnCdS solid solutions for noble-metal-free photocatalytic application.
期刊:
Nuclear Engineering and Technology,2022年54(6):2048-2054 ISSN:1738-5733
通讯作者:
Wenjie Zeng<&wdkj&>Haibiao Wu
作者机构:
[Li, Xiaoyu; Zeng, Wenjie; Li, Chuhao; Hu, Yang; Wu, Haibiao; Yu, Yongqi] Univ South China, Sch Nucl Sci & Technol, Hengyang City 421001, Peoples R China.;[Wu, Haibiao] Univ South China, Affiliated Hosp 1, Hengyang City 421001, Peoples R China.
通讯机构:
[Wenjie Zeng; Haibiao Wu] S;School of Nuclear Science and Technology, University of South China, Hengyang City, 421001, China<&wdkj&>School of Nuclear Science and Technology, University of South China, Hengyang City, 421001, China<&wdkj&>The First Affiliated Hospital, University of South China, Hengyang City, 421001, China
关键词:
Uncertainty quantification;Coolant temperature feedback reactivity;Core power control system;Small PWR
摘要:
The coolant temperature feedback coefficient is an important parameter of reactor core power control system. To study the coolant temperature feedback coefficient influence on the core power control system of small PWR, the core power control system is built with the nonlinear model and fuzzy control theory. Then, the uncertainty quantification method of reactor core parameters is established based on the Latin hypercube sampling method and the Bootstrap method. Finally, under the conditions of reactivity step perturbation and coolant inlet temperature step perturbation, uncertainty analysis for two cases is carried out. The result shows that with fuzzy controller and fuzzy PID controller, the uncertainty of the coolant temperature feedback coefficient affects the core power control system, and the maximum uncertainties of core relative power, coolant temperature deviation, fuel temperature deviation and total reactivity are acceptable. (c) 2022 Korean Nuclear Society, Published by Elsevier Korea LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
摘要:
This paper proposes a method for scintillation detector fault diagnosis based on the Extreme Learning Machine (ELM) algorithm. A related characteristics database is established including the falling edge time, signal amplitude of nuclear pulse signals, and energy spectrum peak channel, low channel address count of energy spectrum signal under various operating conditions. Then a diagnosis model for scintillation detector is created by improved ELM algorithm which have changed the activation function of the hidden layers and modified the number of hidden layers. An experiment system is also constructed for collecting and validating fault data, the diagnostic experiment results show that this method can not only classify the faults of the failed detector, but also distinguish intelligently the severity of various faults.
通讯机构:
[Wang, F ] B;[Mao, F ] U;Beijing Inst Technol, Sch Phys, Beijing 100081, Peoples R China.;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
摘要:
The electronic stopping power of low-energy He projectile particles moving through an Al film under channeling and off-channeling trajectories and its temperature dependence are studied by combining the time-dependent density-functional-theory method with molecular dynamics simulations. The results show that the effect of target temperature on target stopping power can be divided into two aspects which are derived from the target electron and target ion. Below 500 K, the effect of the target-electron temperature on target stopping power is almost negligible. The influence of the target-ion temperature on target stopping power can be divided into two aspects which are derived from the displacement and energy dissipation of target ions. The displacement of the target ion can result in two trends that change the target stopping power: (1) The target ion is closer to the center of lattice channel after displacement, which leads to the increase of target stopping power. (2) The target ion is farther away from the center of the lattice channel after displacement, which leads to the decrease in target stopping power. As the temperature increases, the target ions are more likely to appear farther away from the lattice channel than closer to the center of the lattice channel, so the average displacement of the target ions will lead to a decreasing trend of the target stopping power with the increase of temperature. Under the condition of a given ionic density in the target, the energy dissipation capacity of target ions increases with the increase of temperature, resulting in the tendency of the target stopping power to increase with the increase of temperature. Our calculated stopping powers are in good agreement with the experimental data and reproduced the deviation from velocity proportionality found in the experimental results for a He+ ion in Al, validating our approach and numerical implementation.
期刊:
Energy Reports,2022年8:7325-7335 ISSN:2352-4847
通讯作者:
Longcheng Liu
作者机构:
[Bian, Xiaolei; Zou, Zhi; Liu, Longcheng] KTH Royal Inst Technol, Dept Chem Engn, Teknikringen 42, S-10044 Stockholm, Sweden.;[Liu, Longcheng; Meng, Shuo] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构:
[Longcheng Liu] D;Department of Chemical Engineering, KTH Royal Institute of Technology, Teknikringen 42, 10044 Stockholm, Sweden<&wdkj&>School of Nuclear Science and Technology, University of South China, 421001, Hengyang, China
关键词:
Salinity gradient energy;Capacitive energy extraction;Double layer expansion;CDLE;CDP
摘要:
Capacitive mixing (CapMix) is a renewable method of extracting energy from the salinity difference between seawater and freshwater. In this study, we systematically investigate the system behavior and performance of the CapMix system under four operational modes namely, capacitive energy extraction based on double layer expansion (CDLE), capacitive energy extraction based on the Donnan potential (CDP), and CDP with additional charging of constant voltage (CDP-CV) and constant current (CDPCC). The results indicate that the application of additional charging in the CDP technique can break the limits of the Donnan potential and significantly improve the system's performance. Accordingly, in terms of energy production and average power density, CDP-CC and CDP-CV are the two superior operational modes, followed by CDP and CDLE. In addition, our results reveal that CDP-CC is determined by the accumulated charge and applied current. CDLE is dependent on the applied voltage, while CDPCV is not sensitive to the applied voltage. Increasing the external load can considerably increase the energy production of both CDLE and CDP. In summary, the findings in this study provide practical information for the optimization and application of CapMix technologies. (C) 2022 The Author(s). Published by Elsevier Ltd.
期刊:
Physica Status Solidi-Rapid Research Letters,2022年16(6) ISSN:1862-6254
通讯作者:
Liu, Min;Xia, YF
作者机构:
[Xia, Yanfang; Liu, Min; Liu, M; Mo, Jiajun; Xia, Puyue] Univ South China, Coll Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Chen, Jiangbin] Univ South China, Sch Comp Sci, Hengyang 421001, Peoples R China.
通讯机构:
[Xia, YF ; Liu, M] U;Univ South China, Coll Nucl Sci & Technol, Hengyang 421001, Peoples R China.
关键词:
Cr-doped LaFeO3;magnetic properties;Monte Carlo simulations;Mossbauer spectroscopy
摘要:
Herein, a citric acid combustion method is used to prepare LaFeO3 (LFO) and LaFe0.5Cr0.5O3 (LFCO). Stable and distorted perovskite structures are detected by X-ray diffraction (XRD) patterns of both samples. Due to the substitution of chromium ions, Fe-Fe couplings are wholly disrupted, thus indicating the transition from a sextet to a singlet at room temperature. The M versus T curve of LFO exhibits two anomalous peaks related to Fe-O-Fe superexchange interactions. However, a quite different behavior is observed in LFCO. It reveals the negative irreversibility below 239 K and becomes paramagnetic above 269 K. The field-cooled (FC) curve of LFCO is also simulated using the Monte Carlo method with Heisenberg model. Exchange coupling and anisotropy constants, which indicate some system properties, are calculated by applying the particle swarm algorithm fitting. The Neel temperature of LFCO is determined to be 80 K.
期刊:
Nuclear Engineering and Technology,2022年54(10):3631-3640 ISSN:1738-5733
通讯作者:
Li, C.
作者机构:
[Li, Yongmei; He, Xinqi; Liu, Zhenzhong; Liu, Xinfeng; He, Meijiao; Niu, Qianjin; Li, Chunguang; Yang, Xiaolei; Liu, Qi] Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Liu, Longcheng; Li, Chunguang] China Inst Atom Energy, Beijing 102413, Peoples R China.;[Li, Yongmei; Liu, Zhenzhong; Liu, Longcheng; Meng, Shuo; Li, Chunguang] Univ South China, R&D Ctr Radioact Waste Treatment Disposal & Modeli, Hengyang 421001, Peoples R China.;[Liu, Longcheng; Wang, Wenji; Meng, Shuo] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.
通讯机构:
School of Resource Environment and Safety Engineering, University of South China, Hengyang, China
关键词:
Uranium mill tailings;MBS-MICP grouting;Solidification mechanism;U and Rn immobilization
摘要:
Uranium mill tailing ponds (UMTPs) are risk source of debris flow and a critical source of environmental U and Rn pollution. The technology of microbial induced calcium carbonate precipitation (MICP) has been extensively studied on reinforcement of UMTs, while little attention has been paid to the effects of MICP on U & Rn release, especially when incorporation of metakaolin and bacillus subtilis (MBS). In this study, the reinforcement and U & Rn immobilization role of MBS-MICP solidification in different grouting cycle for uranium mill tailings (UMTs) was comprehensively investigated. The results showed that under the action of about 166.7 g/L metakaolin and similar to 50% bacillus subtilis, the solidification cycle of MICP was shortened by 50%, the solidified bodies became brittle, and the axial stress increased by up to 7.9%, and U immobilization rates and Rn exhalation rates decrease by 12.6% and 0.8%, respectively. Therefore, the incorporation of MBS can enhance the triaxial compressive strength and improve the immobilization capacity of U and Rn of the UMTs bodies solidified during MICP, due to the reduction of pore volume and surface area, the formation of more crystals general gypsum and gismondine, as well as the enhancing of coprecipitation and encapsulation capacity. (C) 2022 Korean Nuclear Society, Published by Elsevier Korea LLC.
通讯机构:
[Chunlin He] S;School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China<&wdkj&>Guangxi Key Laboratory of Processing for Non-Ferrous Metal and Featured Materials, Guangxi University, Nanning 530004, China
摘要:
Abstract: Utilising waste amine-oxime (WAO) resin through microwave semi-carbonization, a carbon adsorbent (CA) was obtained to remove Pb(II). After microwave treatment, the pore size of the skeleton structure, three-dimensional porous network, and lamellar pore structure of WAO was improved. The distribution coefficient (Kd) of Pb(II) onto CA is 620 mL/g, and the maximum adsorption capacity of Pb(II) is 82.67 mg/g after 20 min of WAO microwave treatment. The adsorption kinetics and adsorption isotherms conform to the quasi-second-order kinetic equation and Langmuir adsorption isotherm model, respectively. The surface of MT-WAO is negatively charged and the adsorption mechanism is mainly electrostatic interaction. Pb(II) elution in hydrochloric acid solution is more than 98%, and its recovery is high at 318 K and for 1 h. Keywords: waste amine-oxime; Pb(II); adsorption; adsorbent; microwave
摘要:
Thermally induced spin control is one of the main directions for future spin devices. In this study, we synthesized single-phase polycrystalline ErFe 1−xCrxO3 and combined the magnetization curves and Mössbauer spectra to determine the macroscopic magnetism at room temperature (RT). The magnetization of the system at various temperatures is well simulated by molecular field theory. And it is found that under the Dzyaloshinskii–Moriya (DM) interaction, not only the B-site ions undergo a reorientation process, but the spins of the A-site ions also change at the same time. The effective spin is defined as the projection of Er 3+ on the Fe 3+/Cr 3+ spin plane, and the whole reorientation process is obtained by fitting. This study will complement the actual process of ErFe 1−xCrxO3 spin reorientation and will lay a theoretical foundation for the fabrication of future spin-controlled devices.
通讯机构:
[Min Liu] C;College of Nuclear Science and Technology, University of South China, Hengyang, 421001 China
关键词:
cluster state;molecular field theory;Mossbauer spectroscopy;REBpB'O-1-p(3)
摘要:
This work determines the first calculation of the cluster state of the perovskite REFe1−xCrxO3 system based on magnetic calculations using molecular field theory, using GdFe0.5Cr0.5O3 as an example, and the calculations show that the system has some Fe‐ and Cr‐rich cluster behavior. The calculated results are verified by the Mossbauer spectra. This work has focused on the cluster state of B‐site ions in the rare‐earth perovskite REFepCr1−pO3, and GdFe0.5Cr0.5O3 is taken for instance. This analysis indicates a paramagnetic behavior of the system, which originates from the paramagnetic contribution of the Gd3+. An internal‐field model is used to simplify the superexchange interaction between the A/B‐sites. Furthermore, the cluster state of B‐site ions is computed using the average number of nearest‐neighborhoods. Using Marine Predator Algorithm to fit the experiment data, it is found that Fe–Cr interaction does not conform to the case of ferromagnetic superexchange; therefore, there is no spin glass behavior in this system. Via fitting the Mossbauer spectrum at low temperatures (120 and 12 K), the calculations described above are verified. The calculation gives the hyperfine‐field intervals ΔH of 2.47 and 0.92 T at 120 and 12 K. It is found that B‐site ions tend to form clusters. The arrangement of the ions is random and without the tendency of orderly interval occupation of ions (like double perovskite). The study sheds light on the mechanism of single‐ion clustering and introduces new methods for calculating single‐ion clustering states. It can also be applied to the case of other A‐site ions in perovskite system and is not just limited to p = 0.5 in REBpB’1−pO3.
作者机构:
[Wei, Yuezhou; Hamza, Mohammed F.] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Abu Khoziem, Hanaa A.; Khalafalla, Mahmoud S.; Zaki, Doaa, I; Hamza, Mohammed F.; Abdellah, Walid M.] Nucl Mat Author, POB 530, Cairo 11728, Egypt.;[Althumayri, Khalid] Taibah Univ, Coll Sci, Dept Chem, Al Madinah Al Munawarah 30002, Saudi Arabia.;[Wei, Yuezhou] Shanghai Jiao Tong Univ, Sch Nucl Sci & Engn, Shanghai 200240, Peoples R China.
通讯机构:
[Mohammed F. Hamza; Yuezhou Wei] S;School of Nuclear Science and Technology, University of South China, Hengyang 421001, China<&wdkj&>Nuclear Materials Authority, POB 530, El-Maadi, Cairo 11728, Egypt<&wdkj&>School of Nuclear Science and Technology, University of South China, Hengyang 421001, China<&wdkj&>School of Nuclear Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
关键词:
uranium;metal decontamination;hydrogel;uptake kinetics;sorption isotherms;recovery of heavy metal
摘要:
Abstract: The development of new materials based on biopolymers (as renewable resources) is substantial for environmental challenges in the heavy metal and radionuclide ions removal contaminations. Functionalization of chitosan with sulfonic groups was achieved for improving the uranium sorption, not only from slightly acidic leachate, but also for the underground water. The prepared hydrogel based on chitosan was characterized by series of analysis tools for structure elucidation as FTIR spectroscopy, textural properties using nitrogen adsorption method, pHPZC (by pH-drift method), thermogravimetric analysis (TGA), SEM, and SEM-EDX analyses. The sorption was performed toward uranium (VI) ions for adjustment of sorption performances. The optimum sorption was performed at pH 4 (prior to the precipitation pH). The total sorption was achieved within 25 min (relatively fast kinetics) and was fitted by pseudo-first order rate equation (PFORE) and resistance to intraparticle diffusion equation (RIDE). The maximum sorption capacity was around 1.5 mmol U g−1. The sorption isotherms were fitted by Langmuir and Sips equations. Desorption was achieved using 0.3 M HCl solution and the complete desorption was performed in around 15 min of contact. The sorption desorption cycles are relatively stable during 5 cycles with limit decreasing in sorption and desorption properties (around 3 ± 0.2% and 99.8 ± 0.1%, respectively). The sorbent was used for removal of U from acid leachate solution in mining area. The sorbent showed a highly performance for U(VI) removal, which was considered as a tool material for radionuclides removing from aquatic medium. Keywords: uranium; metal decontamination; hydrogel; uptake kinetics; sorption isotherms; recovery of heavy metal
通讯机构:
[Min Liu] C;College of Nuclear Science and Technology, University of South China, Hengyang, China
关键词:
Prussian blue analogues;pressure-induced;Mossbauer spectroscopy;magnetic properties
摘要:
The effects of pressure on the microstructure and magnetic properties of Co-Fe bistable Prussian blue analogues (PBA) were investigated by Mossbauer spectroscopy and magnetic measurements. Na0.54Co1.23[Fe(CN)(6)]center dot 7.6H(2)O was prepared by the co-precipitation method and pressurized at 1-40 MPa using a supercritical CO2 extraction unit. All materials are face-centered cubic with a Neel temperature of about 14 K. The results showed that two electronic configurations existed in the NaCoFe-PBA system at room temperature: Fe-LS(III)-CN-Co-HS(II) and Fe-LS(II)-CN-Co-LS(III). The pressure induced the enhancement of antiferromagnetic coupling between Co-Fe ions and controlled the interconversion of the two structures through charge transfer mediated by cyanide bridges. We found that the directions of redox reactions occurring at 0-20 MPa and 20-40 MPa did not coincide, suggesting that there may be more complex interactions between structural and electronic events.
期刊:
Annals of Nuclear Energy,2022年176:109295 ISSN:0306-4549
通讯作者:
Yang, Chao(yangc066@163.com)
作者机构:
[Chen, Zhenping; Yang, Chao; Yu, Tao] Univ South China, Sch Nucl Sci & Technol, Hengyang 421200, Peoples R China.;[Chen, Zhenping; Yang, Chao; Yu, Tao] Univ South China, Res Ctr Digital Nucl Reactor Engn & Technol Hunan, Hengyang 421200, Peoples R China.;[Deng, Li; Fu, Yuanguang; Li, Zhipeng] Inst Appl Phys & Computat Math, Beijing 100094, Peoples R China.
通讯机构:
[Chao Yang; Tao Yu] S;School of Nuclear Science and Technology, University of South China, Hengyang 421200, China<&wdkj&>Research Center for Digital Nuclear Reactor Engineering and Technology of Hunan Province, University of South China, Hengyang 421200, China