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Passive neutron multiplicity device for^(240)Pu measurement based on FPGA

Nuclear Science and Techniques 2024年第9期35卷 141-154页

作者： Yan Zhang Hao-Ran Zhang Ren-Bo Wang Ming-Yu Li Rui Chen Hai-Tao Wang Xiang-Ting Meng Shu-Min Zhou Bin Tang Fundamental Science on Radioactive Geology and Exploration technology Laboratory East China University of TechnologyNanchang 330013China Engineering Research Center for Nuclear technology Application Ministry of EducationEast China University of TechnologyNanchang 330013China Pan China Detect technology Co.Ltd. Nanchang 330013China

A passive neutron multiplicity measurement device,FH-NCM/S1,based on field-programmable gate arrays(FPGAs),is developed specifically for measuring the mass of plutonium-240(^(240)Pu)in mixed oxide ***-NCM/S1 adopts an inte-grated approach,combining the shift register analysis mode with the pulse-position timestamp mode using an *** optimal effective length of the^(3)He neutron detector was determined to be 30 cm,and the thickness of the graphite reflector was ascertained to be 15 cm through MCNP *** fabricating the device,calibration measurements were per-formed using a^(252)Cf neutron source;a detection efficiency of 43.07%and detector die-away time of 55.79μs were *** samples of plutonium oxide were measured under identical conditions using the FH-NCM/S1 in shift register analysis mode and a plutonium waste multiplicity *** obtained double rates underwent corrections for detection efficiency(ε)and double gate fraction(f_(d)),resulting in corrected double rates(D_(c)),which were used to validate the accuracy of the shift register analysis ***,the device exhibited fluctuations in the measurement results,and within a single 20 s measurement,these fluctuations remained below 10%.After 30 cycles,the relative error in the mass of^(240)Pu was less than 5%.Finally,correlation calculations confirmed the robust consistency of both measurement *** study holds specific significance for the subsequent design and development of neutron multiplicity devices.

关键词： Spent fuel Non-destructive assay Neutron multiplicity ^(240)Pu FPGA

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Surpassing electrocatalytic limit of earth-abundant Fe^(4+)embedded in N-doped graphene for(photo)electrocatalytic water oxidation

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Journal of Energy Chemistry 2021年第3期30卷 274-281页

作者： Wenjia Xue Feng Cheng Menglu Li Wenjian Hu Congping Wu Bing Wang Kuowei Liao ZhenTao Yu Yingfang Yao Wenjun Luo Zhigang Zou Eco-materials and Renewable Energy Research Center(ERERC) College of Engineering and Applied SciencesNanjing UniversityNanjing 210093JiangsuChina Key Laboratory for Advanced technology in Environment Protection of Jiangsu Province Vancheng Institute of TechnologyYancheng 224051JiangsuChina Jiangsu Key Laboratory for Nano technology National Laboratory of Solid State MicrostructvresDepartment of PhysicsNanjing UniversityNanjing 210093JiangsuChina Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093JiangsuChina Kunshan Innovation Institute of Nanjing University Suzhou 215347JiangsuChina School of Science and Engineering The Chinese University of Hong KongShenzhen2001 Longxiang BlvdLonggang DistrictShenzhen 518172GuangdongChina Macao Institute of Systems Engineering Macao University of Science and TechnologyMacao 999078China Huazhong University of Science and technology Wuhan National Laboratory for OptoelectronicsWuhan 430074HubeiChina

Developing highly active,cost-effective,and environmental friendly oxygen evolution reaction(OER)electrocatalysts facilitates various(photo)electrochemical *** this work,Fe3N nanoparticles encapsulated into N-doped graphene nanoshells(Fe_(3)N@NG)as OER electrocatalysts in alkaline media were *** the experimental and theoretical comparison between Fe_(3) N@NG and Fe_(3)N/NG,specifically including in situ Mossbauer analyses,demonstrated that the NG nanoshells improved interfacial electron transfer process from Fe_(3)N to NG to form high-valence Fe^(4+)ions(Fe^(4+)@NG),thus modifying electronic properties of the outer NG shells and subsequently electron transfer from oxygen intermediate to NG nanoshells for OER catalytic ***,the NG nanoshells also protected Fe-based cores from forming OER inactive and insulated Fe_(2)O_(3),leading to high OER *** a result,the as-formed Fe^(4+)@NG shows one of the highest electrocatalytic efficiency among reported Fe-based OER electrocatalysts,which can as well highly improve the photoelectrochemical water oxidation when used as the cocatalysts for the Fe_(2)O_(3) nanoarray photoanode.

关键词： Fe(Ⅳ) Photoelectrochemistry Water oxidation Oxygen evolution reaction

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Hot Compression Behavior of Mg-Gd-Y-Zn-Zr Alloy Containing LPSO with Different Morphologies

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Acta Metallurgica Sinica(English Letters) 2023年第10期36卷 1680-1698页

作者： Rui Guo Xi Zhao Bo-Wen Hu Xue-Dong Tian Qiang Wang Zhi-Min Zhang School of Material Science and Engineering North University of ChinaTaiyuan030051China School of Aeronautics and Astronautics North University of ChinaTaiyuan030051China

In this study,hot compression behavior of as-homogenized Mg-9Gd-4Y-2Zn-0.5Zr alloys containing long period ordered(LPSO)phases with different initial morphologies was investigated under a strain rate of 0.01 s−1 at 450°*** microstructure,texture evolution and dynamic recrystallization(DRX)mechanism under different strains(0.1,0.3,0.5,0.7,and 1.4)were *** compression conditions,the block-shape phase and deformedα-Mg matrix were regularly arranged vertically in the compression direction(CD).The particle phase(Mg5RE)and amount of kink bands were *** degree of kink increased initially and decreased significantly when the deformation strain reached *** DRX mechanisms were produced during the compression process:(i)The block LPSO,Mg5RE and Zr-Zn phase activated DRX through the particle stimulated nucleation(PSN)mechanism.(ii)Several DRX activated on the serrated grain boundary between the two parent grains through discontinuous DRX(DDRX)mechanism.(iii)A large number of kink bands and larger spacing of lamellar LPSO increased the nucleation of DRX through continuous DRX(CDRX)*** combination of different recrystallization mechanisms has evident effects on grain *** increased as compression proceeds,and the texture was gradually weakened.

关键词： Mg-Gd-Y-Zn-Zr alloy Compression Long period ordered(LPSO)phase Recrystallization mechanism

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Effect of aging treatment on the precipitation transformation and age hardening of Mg-Gd-Y-Zn-Zr alloy

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Journal of Magnesium and Alloys 2023年第12期11卷 4628-4643页

作者： Mu Meng Honglei Zhang Zhi Gao Genxing Lei Jianmin Yu College of Materials Science and Engineering North University of ChinaXueyuan Road 3Taiyuan 030051China Beijing North Vehicle Group Corporation ZhuJiaFen 5th LiBeijing 100072China

In this study, the precipitation transformation and age hardening of solution-treated Mg-9Gd-4Y-2Zn-0.5Zr(wt.%) alloy were investigated at different aging treatment parameters. The precipitation sequences of the alloy aged at 200℃, 250℃ and 300℃ are β’’(DO19) → β’(BCO) → β(FCC), β’’(DO19) → β’(BCO) → β_(1)(FCC) → β(FCC) and β(FCC), respectively. The streaks sequences of the alloy aged at 200℃, 250℃ and 300℃ are SF, SF → 14H-LPSO and SF → 14H-LPSO, respectively. For the alloy aged at 200℃ and 250℃, the increase in hardness with increasing aging time is contributed from the increase in precipitate volume fraction and the transformation from β’’ to β’ phase with basal → prismatic and spherical → spindle-like precipitate changes. The decrease in hardness after the peak-aging stage is attributed to the appearance of micro-sized β precipitates. Because of the smaller size of precipitates and the triangular arrangement of β’ precipitate, the hardness of the alloy aged at 200℃ is higher than that aged at 250℃. For the alloy aged at 300℃, the appearance of only micro-sized β precipitate and its coarsening with increasing aging time leads to the lowest hardness and an overall decrease in hardness with the aging time.

关键词： Mg-Gd-Y-Zn-Zr alloy Aging treatment Precipitation transformation Age hardening

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Anchoring Iron-EDTA Complex on Graphene toward the Synthesis of Highly Efficient Fe-N-C Oxygen Reduction Electrocatalyst for Fuel Cells

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Chinese Journal of Chemistry 2018年第4期36卷 287-292页

作者： Zhi-Wen Chang Fan-Lu Meng Hai-Xia Zhong Xin-Bo Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied Chemistry Chinese Academy of Sciences Changchun Jilin 130022 China University of Chinese Academy of Sciences Beijing 100049 China

Developing nonprecious carbon electrocatalysts as alternatives to platinum for cathodic oxygen reduction reaction in fuel cells is of signifi- cance. Herein, an efficient precursor-controlled synthesis strategy based on extremely rapid nucleation and deposition process assisted by the liquid nitrogen freeze drying method is explored to anchor cheap iron-EDTA complex evenly dispersed on graphene to realize mJcrostructural homogeneity of the derived Fe-N-C oxygen reduction electrocatalyst. The prepared electrocatatyst possesses excellent performance including high activity with more positive onset and half-wave potential, a long-term stability, and anti-poisoning effect compared to commercial Pt/C. The activity correlates well with the unique sheet-shaped morphology, high surface area, hierarchical porous structure, and the introduction of Fe-Nx/C species. Especially, both the assembled practical alkaline and acid fuel cells based on the synthesized cathode catalysts reveal excellent performance with high open-circuit voltage and power density.

关键词： iron-EDTA complex iron-nitrogen-doping carbon porous nanosheets oxygen reduction reaction fuel cells

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Evaluation of the Biodiversity Conservation Function in Liaohe Delta Wetland,Northeastern China

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Journal of Meteorological Research 2020年第4期34卷 798-805页

作者： Wenying YU Ruipeng JI Xiuzhen HAN Long CHEN Rui FENG Jinwen WU Yushu ZHANG Institute of Atmospheric Environment China Meteorological AdministrationShenyang 110166 Key Laboratory of Agrometeorological Disasters of Liaoning Province Shenyang 110166 national Satellite Meteorological Center Beijing 100081 Panjin Meteorological Bureau Panjin 124010

The scientific evaluation of the wetland biodiversity conservation function is the basis of balanced wetland protection and development. Our research sought to provide references for the protection of wetland ecological environments as well as the related planning and management policies. The study established a fitting model for evaluating the biodiversity conservation function in the Liaohe Delta, northeastern China. The new model, the Wetland Biodiversity Conservation Indicator(WBCI), was with four input factors, including the vegetation coverage(VC), habitat suitability index(HI), land use and land cover(LULC) index(LI), and threat factor index(TI) of the LULC type. The values assigned to HI and TI were based on Integrated Valuation of Ecosystem Services and Tradeoffs(In VEST)habitat quality models. The weights of all the factors in WBCI were valued with the Principal Component Analysis(PCA). We evaluated the wetland biodiversity conservation function of Panjin, Liaohe Delta, China, by using the WBCI model based on Gaofen-1(GF-1) satellite data in 2018, and the result was verified with In VEST and other models. It showed that the output map was similar to that of In VEST, with the higher-quality habitat including the wetland, tidal flat, water body, and forest, as well as the lower-quality land use types including the paddy field, crop field, construction land, and land used by traffic. The wetland biodiversity conservation function was better in areas less affected by human disturbance, with very abundant species and good-quality habitat. It was poor in areas impacted by more frequent human activities such as the land cultivation, housing, and traffic, which led to the landscape fragmentation. The WBCI model provided a more accurate reflection of the bird distribution than the In VEST model. The WBCI model was able to reflect the difference in quality of each habitat grade, in contrast to the net primary productivity(NPP) method and species distribution models(

关键词： wetland biodiversity conservation function habitat quality evaluation

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Physical mechanism of secondary-electron emission in Si wafers

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Chinese Physics B 2024年第4期33卷 677-681页

作者：赵亚楠孟祥兆彭淑婷苗光辉高玉强彭斌崔万照胡忠强 State Key Laboratory for Manufacturing Systems Engineering Electronic Materials Research LaboratoryKey Laboratory of the Ministry of EducationEngineering Research Center of Spin Quantum Sensor ChipsUniversities of Shaanxi ProvinceSchool of Electronic Science and EngineeringXi'an Jiaotong UniversityXi'an 710049China College of Aeronautics Nanjing University of Aeronautics and AstronauticsNanjing 210016China national Key Laboratory of Science and technology on Space Microwave China Academy of Space TechnologyXi'an 710100China Department of Physics School of Physics and Electronic InformationAnhui Normal UniversityWuhu 241000China

CMOS-compatible RF/microwave devices,such as filters and amplifiers,have been widely used in wireless communication ***,secondary-electron emission phenomena often occur in RF/microwave devices based on silicon(Si)wafers,especially in the high-frequency *** this paper,we have studied the major factors that influence the secondary-electron yield(SEY)in commercial Si wafers with different doping *** show that the SEY is suppressed as the doping concentration increases,corresponding to a relatively short effective escape depthλ.Meanwhile,the reduced narrow band gap is beneficial in suppressing the SEY,in which the absence of a shallow energy band below the conduction band will easily capture electrons,as revealed by first-principles ***,the new physical mechanism combined with the effective escape depth and band gap can provide useful guidance for the design of integrated RF/microwave devices based on Si wafers.

关键词： secondary-electron yield doping concentration escape depth Si wafer

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Comparison between the 3D numerical simulation and experiment of the bubble near different boundaries

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Science China(Physics,Mechanics & Astronomy) 2008年第12期51卷 1914-1925页

作者： ZHANG AMan YAO XiongLiang LI Jia GUO Jun College of Shipbuilding Engineering Harbin Engineering UniversityHarbin 150001China

Based on the potential flow theory, the vortex ring is introduced to simulate the toroidal bubble, and the boundary element method is applied to simulate the evo- lution of the bubble. Elastic-plasticity of structure being taken into account, the interaction between the bubble and the elastic-plastic structure is computed by combining the boundary element method (BEM) and the finite element method (FEM), and a corresponding 3D computing program is developed. This program is used to simulate the three-dimensional bubble dynamics in free field, near wall and near the elastic-plastic structure, and the numerical results are compared with the existing experimental results. The error is within 10%. The effects of different boundaries upon the bubble dynamics are presented by studying the bubble dy- namics near different boundaries.

关键词： bubble three-dimensional potential flow theory elastic-plasticity boundary

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Application of a mixed DEA model to evaluate relative efficiency validity

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Journal of Marine Science and Application 2005年第3期4卷 64-70页

作者： FU Yu-wei YIN Hang YANG Gui-bin School of Economics and Management Harbin Engineering University Harbin 150001 China

Data envelopment analysis(DEA) model is widely used to evaluate the relative efficiency of producers. It is a kind of objective decision method with multiple indexes. However, the two basic models frequently used at present, the C2R model and the C2GS2 model have limitations when used alone,resulting in evaluations that are often unsatisfactory. In order to solve this problem, a mixed DEA model is built and is used to evaluate the validity of the business efficiency of listed companies. An explanation of how to use this mixed DEA model is offered and its feasibility is verified.

关键词： decision making units (DMU) efficiency evaluating mixed data envelopment analysis (DEA) model relative efficiency

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Research on basic characteristics of complex system brittleness

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Journal of Marine Science and Application 2004年第1期3卷 57-63页

作者： JINHong-zhang GUOJian WEIQi LINDe-ming LIQi SchoolofAutomation HarbinEngineeringUniversityHarbin150001China

The goal of this paper is to research one new characteristic of complex system. Brittleness, which is one new characteritic of complex system, is presented in this paper. The linguistic and qualitative descriptions of complex system are also given in this paper. Otherwise, the qualitative description of complex system is presented at first. On the basis of analyzing the existing brittleness problems, linguistic description and mathematic description of brittleness are given as well. Three kinds of phenomena to judge brittleness of complex system are also given, based on catastrophe theory. Basic characteristics of brittleness are given on the basis of its mathematic description. Two critical point sets are defined by using catastrophe theory. The definition of brittleness and its related theory can serve the control of complex system, and provide theoretical basis for the design and control of complex system.

关键词： brittleness complex system criterion basic characteristic catastrophe theory

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