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Reduced-order method for nuclear reactor primary circuit calculation

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Nuclear Science and Techniques 2024年第11期35卷 28-45页

作者： Ze-long Zhao Ya-Hui Wang Zhe-Xian Liu Hong-hang Chi Yu Ma Sino‑French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

Accurate real-time simulations of nuclear reactor circuit systems are particularly important for system safety analysis and *** effectively improve computational efficiency without reducing accuracy,this study establishes a thermal-hydraulics reduced-order model(ROM)for nuclear reactor circuit *** full-order circuit system calculation model is first established and verified and then used to calculate the thermal-hydraulic properties of the circuit system under different states as *** proper orthogonal decomposition method is used to extract the basis functions from snapshots,and the ROM is constructed using the least-squares method,effectively reducing the difficulty in constructing the ROM.A comparison between the full-order simulation and ROM prediction results of the AP1000 circuit system shows that the proposed ROM can improve computational efficiency by 1500 times while achieving a maximum relative error of 0.223%.This research develops a new direction and perspective for the digital twin modeling of nuclear reactor system circuits.

关键词： Reactor system model Primary circuit Reduced-order Proper orthogonal decomposition Least-squares method

A new consecutive energy calibration method for X/γ detectors based on energy continuously tunable laser Compton scattering light source

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Nuclear Science and Techniques 2017年第9期28卷 8-15页

作者： hang-Hua Xu Hai-long Wu Gong-Tao Fan Jian-Hui Chen Dong Wang Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049China

In this paper, we present an energy calibration method based on steep Compton edges of the laser Compton scattered(LCS) photon energy spectra. It performs consecutive energy calibration in the neighborhood of certain energy, hence improves calibration precision in the energy region. It can also achieve direct calibration at high energy region(several MeV) where detectors can only be calibrated by extrapolation in conventional *** make it suitable for detectors that need wide-range energy calibration with high precision. The effects of systematic uncertainties on accuracy of this calibration method are studied by simulation, using the design parameters of a LCS device—SINAP Ⅲ. The results show that the SINAP Ⅲ device is able to perform energy calibration work over the energy region of 25–740 keV. The precision of calibration is better than 1.6% from 25 to 300 keV and is better than 0.5% from 300 to 740 keV.

关键词：康普顿散射连续能量可调谐激光 γ探测器校准光源标定方法标定精度

Variational quantum algorithm for node embedding

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Fundamental Research 2024年第4期4卷 845-850页

作者： Zeng-rong Zhou hang Li Gui-Lu long Research Center for Quantum Sensing Zhejiang LabHangzhou 311121China Bejing Academy of Quantum Information Sciences Beijing 100193China State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China

Quantum machine learning has made remarkable progress in many important ***,the gate complexity of the initial state preparation is seldom considered in lots of quantum machine learning algorithms,making them ***,we propose a quantum algorithm for the node embedding problem that maps a node graph's topological structure to embedding *** resulting quantum embedding state can be used as an input for other quantum machine learning *** O(log(N))qubits to store the information of N nodes,our algorithm will not lose quantum advantage for the subsequent quantum information ***,owing to the use of a parameterized quantum circuit with O(poly(log(N)))depth,the resulting state can serve as an efficient quantum *** addition,we explored the measurement complexity of the quantum node embedding algorithm,which is the main issue in training parameters,and extended the algorithm to capture high-order neighborhood information between ***,we experimentally demonstrated our algorithm on an nuclear magnetic resonance quantum processor to solve a graph model.

关键词： Quantum machine learning Quantum computation Node embedding Variational quantum algorithm Nuclear magnetic resonance

Alloy strategy to synthesize Pt-early transition metal oxide interfacial catalysts

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Nano Research 2024年第4期17卷 3390-3397页

作者： Shi-long Xu hang Nan Wanqun Zhang Yue Lin Sheng-Qi Chu Hai-Wei Liang Hefei National Research Center for Physical Sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei 230026China School of Materials and Chemical Engineering Anhui Jianzhu UniversityHefei 230601China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Metal oxide supported metal catalysts show promising catalytic performance in many industry-relevant ***,the enhancement of performance is often limited by the insufficient metal/metal oxide *** this work,we demonstrate a general synthesis of Pt-early transition metal oxide(Pt-MO_(x),M=Ti,Zr,V,and Y)catalysts with rich interfacial sites,which is based on the air-induced surface segregation and oxidation of M in the supported Pt-M alloy *** characterizations verify the dynamic structural response of Pt-M alloy catalysts to air and the formation of Pt-MO_(x) catalysts with abundant interfacial *** prepared Pt-TiO_(x) interfacial catalysts exhibit improved performance in hydrogenation reactions of benzaldehyde,nitrobenzene,styrene,and furfural,as a result of the heterolytic dissociation of H_(2) at Pt-metal oxide interfacial sites.

关键词： Pt-early transition metal oxide interfacial catalyst alloy oxidation strategy interfacial sites hydrogenation reactions heterolytic dissociation

A novel low pressure-difference fluctuation electro-hydraulic large flowrate control valve for fuel flowrate control of aeroengine afterburner system

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Chinese Journal of Aeronautics 2022年第11期35卷 363-376页

作者： Jie hang Yunhua LI Liman YANG School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China

To address the control accuracy of large fuel flowrate during pressure fluctuation,a novel electro-hydraulic fuel metering unit(FMU)is constructed for afterburner fuel system of military *** from the previous FMU,the proposed FMU can achieve the higher precision opening control by a new metering valve with double control chambers(MVDCC),and realize the lower pressure difference fluctuation regulating by a novel two-stage constant pressure difference compensated valve(CPDCV)with dynamic damping orifice and damping *** experimental and AMESim simulation results verify the validity and superiority of the novel *** the temperature-induced variation in fuel properties and device capabilities may degrade or even impair the properties of novel FMU,the discharge flowrate is analyzed by global sensitivity analysis to research the effect proportion of each factor,the temperature effect is explored to ensure the working reliability in long-span temperature ***,the optimization of structure parameters for novel CPDCV can further reduce pressure difference fluctuation during pressure regulation,and the overshoot,adjust time and the integral of time multiplied by absolute value of error(ITAE)can be reduced by 24%,30%and 26%,*** paper provides a reference for improving the stability of large flowrate during pressure fluctuation.

关键词： Aeroengine Fuel metering unit Large flowrate control Optimization Pressure difference compensation

Evaluating the accuracy of two satellite-based Quantitative Precipitation Estimation products and their application for meteorological drought monitoring over the Lake Victoria Basin,East Africa

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Geo-Spatial Information Science 2022年第3期25卷 500-518页

作者： Priyanko Das Zhenke Zhang hang Ren Center of African Studies Nanjing UniversityNanjingChina and School of Geographic and Oceanographic SciencesNanjing UniversityNanjingChina Center of African Studies Nanjing UniversityNanjingChina and School of Geographic and Oceanographic SciencesNanjing University Nanjing China Institute of Population Studies Nanjing University of Posts and TelecommunicationsNanjingJiangsu provinceChina

This study evaluates the high-resolution satellite estimated long-term precipitation data for monitor-ing the drought condition over the Lake Victoria Basin(LVB)from 1984 to *** Precipitation Indices(SPI)were used to capture the short,medium and long-term meteorological drought conditions at multiple time scales(i.e.3,6,and 12).For these,the following two primaries Quantitative Precipitation Estimation(QPEs)products were employed-1)Climate Hazards group Infra-Red Precipitation with Station(CHIRPS),and 2)the Precipitation Estimation from Remotely Sensed Information using Artificial Neural Network-Climate Data Record(PERSIANN-CDR).This dataset was compared based on the observation data obtained from the Climate Research Unit(CRU)over the nine selected regions surrounding lake *** performance of these two QPEs products was evaluated using seven statistical *** findings of this study indicate that the CHIRPS and PERSIANN-CDR datasets could capture the behavior of drought magnitude based on the time scale of SPI-3,SPI-6,*** results indicate that 2012 and 2017 are significant severe drought years in the recent decade over ***,the CHIRPS datasets provide good agreement(Correlation Coefficient(CC)=0.65)with observation,whereas PERSIANN-CDR present satisfactory results(CC=0.54).In addition,Hurst(H)exponent was used to predict the future drought trend and found that the CHIRPS performed well to predict the degree of drought ***,this study considers the CHIRPS product for near-real-time drought monitoring and PERSIANN-CDR for historical drought ***,the outcome from the H values is greater than 0.5,which indicates the future drought trend would be decreased over *** results are useful for developing the strategies for drought hazards and water resource management in LVB.

关键词： CHIRPS CRU hurst exponent PERSIANN-CDR SPI

Reduction characteristics of molybdenum trioxide with aluminum and silicon

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Rare Metals 2018年第7期37卷 621-624页

作者： hang-Yu Zhu Rong Gao Wu-Tao Jin long-Wu Qiu Zheng-Liang Xue State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology School of Materials and Metallurgy Wuhan University of Science and Technology

Thermodynamics for reduction of molybdenum oxides by aluminum and silicon were calculated, and the results show that reduction reaction is feasible at a certain temperature region. Compared to the presence of CaO or CaCO3, reduction products of molybdenum trioxide with aluminum and silicon at various temperatures were detected by X-ray diffraction （XRD）. Results show that molybdenum trioxide is reduced by aluminum or silicon step by step, and the intermediate product is MOO2. At 1000 ℃, molybdenum trioxide could be reduced to metal Mo by aluminum, and in the presence of CaO, metal Mo as the reduction product appears even at 800 ℃. In contrast, silicon could barely reduce molybdenum trioxide to metal Mo even at 1200℃. In the presence of CaO or CaCO3, reducibility of silicon increases significantly, and the reduction products are metal Mo and MoSi2. Altogether, CaO or CaCO3 performs two major roles in reduction process： restraining sublimation of MoO3 and decreasing the temperature of reducing MoO3 to metal Mo.

关键词： Molybdenum trioxide Reduction Aluminum Silicon Metallothermic

Microstructural development and wear properties analyses of Fe-based coatings on bainitic steel by laser cladding

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Journal of Iron and Steel Research International 2022年第4期29卷 687-697页

作者： Run-feng Peng Min Zhang Yu-hang Li Yue-long Yu Ying-chun Guan Zhun-li Tan School of Mechanical Electronic and Control EngineeringMaterials Science&Engineering Research CenterBeijing Jiaotong UniversityBeijing 100044China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China National Engineering Laboratory of Additive Manufacturing for Large Metallic Components Beihang UniversityBeijing 100083China Hefei Innovation Research Institute of Beihang University Hefei 230013AnhuiChina

Wear-resistant Fe-based coating was prepared by high-speed laser cladding on bainitic *** influence of laser scanning speed on microstructure,microhardness,and wear resistance of cladding coating was *** electron microscopy results showed that the coating was mainly composed of dendrite and *** electron microscope images were converted by binary algorithm to facilitate statistics of dendrite and interdendrite *** results indicate that by accelerating the scanning speed,the interdendrite eutectic structure *** to energydispersive X-ray spectroscopy and X-ray diffraction results,the interdendrite was enriched with elements Cr,Mo,and B,and main structures in the coating wereα-Fe,γ-Fe,and M(23)C_(6).The hardness of the coating was much higher than that of the *** diffused from coating to substrate,resulting in a transition zone of ***,with an increase in the scanning speed,the diffusion of elements at the coating–matrix interface decreased,while the hardness and wear resistance of the coating *** refinement and interdendrite(γ-Fe,M_(23)C_(6))increasing due to high scanning speed were the major contributors to the increase in hardness and wear resistance.

关键词： Laser cladding Microstructure Wear property Fe-based coating Bainitic steel

Estimation of Energy Consumption in COREX Process Using a Modified Rist Operating Diagram

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Journal of Iron and Steel Research International 2015年第12期22卷 1078-1084页

作者： Wen-long ZHAN Keng WU Zhi-jun HE Qi-hang LIU Xiao-juan WU School of Materials and Metallurgy University of Science and Technology Liaoning State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Fuel consumption in the COREX-3000 process run in Baosteel is currently higher than the design index. Therefore, mass and heat balance equations for the COREX process were established using the basic principles in- cluded in the Rist operating diagram for blast furnace （BF） as a reference. Thermodynamic calculations were then used to modify the Rist operating diagram so that it was suitable for the COREX process. The modified Rist operating dia- gram was then applied for the evaluation of metallization rate （MR） and fuel structure to reduce the energy consump- tion in the COREX process. The modified Rist operating diagram for the shaft furnace （SF） provided a nearly ideal value for the restriction point W when the metallization rate was increased, while the point P on the operating line for the melter gasifier （MG） moved upward due to reduction in the heat required in hearth. The feasibility of reduc- ing the energy consumption during the COREX process by changing the fuel structure was also demonstrated.

关键词： modified Rist operating diagram metallization rate fuel structure energy consumption COREX process