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Nuclear Science and Techniques 2019年第8期30卷 66-76页

作者： Pu Yang Ye Dai Yang Zou Rui Yan Bo Zhou shi-he yu yu-Wen Ma Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

The solid fuel thorium molten salt reactor(TMSR-SF1) is a 10-MWth fluoride-cooled pebble bed reactor. As a new reactor concept, one of the major limiting factors to reactor lifetime is radiation-induced material damage. The fast neutron flux(E > 0.1 MeV) can be used to assess possible radiation damage. hence, a method for calculating high-resolution fast neutron flux distribution of the full-scale TMSR-SF1 reactor is required. In this study,a two-step subsection approach based on MCNP5 involving a global variance reduction method, referred to as forward-weighted consistent adjoint-driven importance sampling, was implemented to provide fast neutron flux distribution throughout the TMSR-SF1 facility. In addition,instead of using the general source specification cards, the user-provided SOURCE subroutine in MCNP5 source code was employed to implement a source biasing technique specialized for TMSR-SF1. In contrast to the one-step analog approach, the two-step subsection approach eliminates zero-scored mesh tally cells and obtains tally results with extremely uniform and low relative ***, the maximum fast neutron fluxes of the main components in TMSR-SF1 are provided, which can be used for radiation damage assessment of the structural materials.

关键词： TMSR-SF1 Fast neutron flux Globalvariance reduction MCNP

A Glycosylated and Catechol-crosslinkedε-Polylysine Hydrogel:Simple Preparation and Excellent Wound hemostasis and healing Properties

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Chinese Journal of Polymer Science 2022年第9期40卷 1110-1119页

作者： Lin Teng Zheng-Wei Shao yu-shi he Jia-yu Lu De-Rong Zou Chuan-Liang Feng Chang-Ming Dong School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgingShanghai Jiao Tong UniversityShanghai 200240China Department of Stomatology Shanghai Jiao Tong University Affiliated Sixth People’s HospitalShanghai Jiao Tong UniversityShanghai 200233China School of Chemistry and Chemical Engineering Shanghai Electrochemical Energy Devices Research CenterShanghai Jiao Tong UniversityShanghai 200240China School of Materials Science and Engineering State Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200240China

Commercial tissue adhesives have been widely applied in wound hemostats and dressings while enhancing the hemostasis and healing capabilities is challenging to meet clinical ***,we designed the glucose-and catechol-functionalized derivatives from commercialε-polylysine(EPL)and prepared the hydrogels by simple amidation and catechol-crosslinking reactions,which have larger swelling ratios of 220%–240%,suitable microporous size of about 6–8µm,and tissue adhesion strength of about 20–40 *** hemolysis,cytotoxicity,and cellular double-staining assays indicate that those hydrogels had good biocompatibility and the H-3 hydrogel with higher glucose content gave a lower hemolysis ratio of 0.73%±0.14%.The blood-clotting index,blood cell attachment and adhesion studies showed those hydrogels had fast blood-coagulation,resulting in excellent hemostasis performance with a short hemostatic time of 38–46 s and less blood loss of 19%–34%in a liver hemorrhage model.A full-thickness rat-skin defect model further demonstrates that the H-3 hydrogel achieved fast wound healing with a wound closure of 70.0%±2.7%on postoperative day 7 and nearly full closure on day ***,the hydroproline level that denotes the collagen production reached a higher one of 7.24±0.55µg/mg comparable to that in normal skins on day 14,evidencing the wound healing was close to completion in the H-3 ***,this work provides a simple method to construct a glycosylated and catechol-functionalized hydrogel platform from commercial EPL,holding translational potentials in wound hemostats and dressings.

关键词： Polylysine hydrogel Glycosylation Mussel-mimetic hemostasis Wound dressing

Evaluation of the fraction of delayed photoneutrons for TMSR-SF1

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Nuclear Science and Techniques 2017年第9期28卷 129-136页

作者： Rui-Min Ji Ye Dai Gui-Feng Zhu shi-he yu Yang Zou Gui-Min Liu Shanghai Institute of Applied Physics Chinese Academy of Sciences Jiading Campus Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049China

The 10 MW_(th) solid-fueled thorium molten salt reactor(TMSR-SF1) is a FLi Be salt-cooled pebble bed reactor to be deployed in 5–10 years, designed by the TMSR group. Due to a large amount of beryllium in the core, the photoneutrons are produced via(γ , n) *** of them are generated a long time after the fission event and therefore are considered as delayed neutrons. In this paper, we redefine the effective delayed neutrons into two fractions: the delayed fission neutron fraction and the delayed photoneutron fraction. With some reasonable assumptions, the inner product method and the k-ratio method are adopted for studying the effective delayed photoneutron fraction. In the k-ratio method, the Monte Carlo code MCNP6 is used to evaluate the effective photoneutron fraction as the ratio between the multiplication factors with and without contribution of the delayed neutrons and photoneutrons. In the inner product method, with the Monte Carlo and deterministic codes together, we use the adjoint neutron flux as a weighting function for the neutrons and photoneutrons generated in the core. Results of the two methods agree well with each other, but the k-ratio method requires much more computing time for the same precision.

关键词：碰撞后分数延迟系数倍率法裂变中子评价缓发中子蒙特卡洛

The Wear Process of PTFE Coatings Under Vacuum Conditions

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Journal of Harbin Institute of Technology(New Series) 2014年第1期21卷 121-124页

作者： Xing-Dong yuan Yong Liu De-Zhuang Yang shi-yu he School of Materials Science and Engineering Shandong Jianzhu University Space Material and Environment Engineering Lab. Harbin Institute of Technology

The wear process of PTFE coatings sliding against GCr15-bearing steel ball under vacuum conditions was investigated,and the hardness of the PTFE coatings on both sides of wear track was measured. The experimental results showed that the friction coefficient of the PTFE coatings increases with the increase of sliding distance under different sliding velocities. And the friction coefficient of the PTFE coatings increases with the increase of sliding distance under different sliding loads. The wear rate of PTFE coatings decreases with the increase of sliding distance. And the majority of the wear produced during the whole wear process of PTFE coatings sliding against GCr-15 steel ball comes from the early period of friction. The hardness of PTFE coatings on both sides of wear track increases as the distance increases and distributes symmetrically around the wear track. Scanning electron microscope( SEM) was utilized to investigate the worn surface of PTFE coating. It was found that the worn surface of PTFE coating is characterized by sever plastic deformation and spalling of the PTFE coating. The edge of wear track is characterized by micro cracking.

关键词： sliding wear two-body abrasion polymers high vacuum

Study on dynamic characteristics of fission products in 2 MW molten salt reactor

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Nuclear Science and Techniques 2020年第2期31卷 42-54页

作者： Bo Zhou Xiao-Han yu Yang Zou Pu Yang shi-he yu Ya-Fen Liu Xu-Zhong Kang Gui-Feng Zhu Rui Yan Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

In this study,a numerical flow model of the fission products(FPs)in the primary loop system of a molten salt reactor(MSR)was established and solved using Mathematica *** simulation results were compared with those of the ORIGEN-S program in the static burnup mode,and the deviation was found to be less than 10%,which indicates that the results are in good ***,the FPs distribution in the primary loop system under normal operating conditions of the 2 MW MSR was quantitatively *** addition,the distribution phenomenon of the FPs under different flow rate conditions was *** the end of life,the FPs activity in the core region(including active region,and upper and lower plenum regions)accounted for 77.3%,and that in the hot leg #1,main pump,hot leg #2,heat exchanger,and cold leg region accounted for 1.2%,16.15%,0.99%,2.5%,and 1.9%,respectively,of the total FPs in the primary loop under normal operating *** proportion of FPs in the core decreased with the increase in flow rate in the range of 2.24-22,400 cm^3 s^-*** established analytical method and conclusions of this study can provide an important basis for radiation safety design of the primary loop,radioactive source management design,thermal-hydraulic safety analysis,and radiochemical analysis of FPs of 2 MW MSRs.

关键词： Molten salt reactor Fission products Radioactive source term Primary loop system Flow model

Neutronics analysis for MSR cell with different fuel salt channel geometries

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Nuclear Science and Techniques 2021年第1期32卷 75-84页

作者： shi-he yu Ya-Fen Liu Pu Yang Rui-Min Ji Gui-Feng Zhu Bo Zhou Xu-Zhong Kang Rui Yan Yang Zou Ye Dai Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

The neutronic properties of molten salt reactors(MSRs)differ from those of traditional solid fuel reactors owing to their nuclear fuel *** on the Monte-Carlo N particle transport code,the effects of the size and shape of the fuel salt channel on the neutron physics of an MSR cell are investigated systematically in this *** results show that the infinite multiplication factor(k?)first increases and then decreases with the change in the graphite cell size under certain fuel volume fraction(FVF)*** the same FVF and average chord length,when the average chord length is relatively small,the k?values for different fuel salt channel shapes agree *** the average chord length is relatively large,the k?values for different fuel salt channel shapes differ *** addition,some examples of practical applications of this study are presented,including cell selection for the core and thermal expansion displacement analysis of the cell.

关键词： Molten salt reactor Fuel salt channel Cell geometry Neutronics

Application of Monte Carlo method to calculate the effective delayed neutron fraction in molten salt reactor

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Nuclear Science and Techniques 2019年第2期30卷 143-152页

作者： Gui-Feng Zhu Rui Yan Hong-Hua Peng Rui-Min Ji shi-he yu Ya-Fen Liu Jian Tian Bo Xu Shanghai Institute of Applied Physics Chinese Academy of Sciences

Delayed neutron loss is an important parameter in the safety analysis of molten salt reactors. In this study,to obtain the effective delayed neutron fraction under flow condition, a delayed neutron precursor transport was implemented in the Monte Carlo code MCNP. The moltensalt reactor experiment(MSRE) model was used to analyze the reliability of this method. The obtained flow losses of reactivity for 235 U and 233 U fuels in the MSRE are223 pcm and 100.8 pcm, respectively, which are in good agreement with the experimental values(212 pcm and100.5 pcm, respectively). Then, six groups of effective delayed neutron fractions in a small molten salt reactor were calculated under different mass flow rates. The flow loss of reactivity at full power operation is approximately105.6 pcm, which is significantly lower than that of the MSRE due to the longer residence time inside the active core. The sensitivity of the reactivity loss to other factors,such as the residence time inside or outside the core and flow distribution, was evaluated as well. As a conclusion,the sensitivity of the reactivity loss to the residence time inside the core is greater than to other parameters.

关键词： Monte Carlo Effective delayed neutron fraction Molten salt reactor

Constructing a"pea-pod"-like nanostructure to provide valid conductive matrix and volume change accommodation for silicon anode in lithium ion batteries

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Green Chemical Engineering 2021年第3期2卷 327-335页

作者： Jingjing Ma Huan Zhang yuanchao Li Linfeng Hu Qing Wang WanQing Zhang Li Yang Guang-Ri Xu yu-shi he Tianjun Lou Zi-Feng Ma College of Chemistry and Chemical Engineering Henan Institute of Science and TechnologyHenan453003China Shanghai Electrochemical Energy Devices Research Center School of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai200240China

A"pea-pod"-like composite of graphene-wrapped silicon nanoparticles(P–Si@GS)was successfully prepared via a new and facial technique utilizing freeze-drying and subsequent solvothermal *** cross-linked"pods"formed by curled few-layer graphene sheets constituted a conductive network,in which silicon nanoparticles were tightly *** unique graphene-wrapped structure with mesopores on the surface can effectively enhance the conductivity of silicon,alleviate its volume effect and provide rapid transport channels for electrons and ions,thus resulting in excellent electrochemical *** strategy of combining freeze-drying and solvothermal methods is facile,low-cost and effective,which provides new ideas for the preparation of highperformance graphene-wrapped nanoparticles composites.

关键词： Silicon Graphene Anode material Freeze-drying Lithium-ion battery

Study on neutronics design of ordered-pebble-bed fluoride-salt- cooled high-temperature experimental reactor

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Nuclear Science and Techniques 2018年第6期29卷 36-44页

作者： Rui Yan shi-he yu Yang Zou Qun Yang Bo Zhou Pu Yang Hong-Hua Peng Ya-Fen Liu Ye Dai Rui-Ming Ji Xu-Zhong Kang Xing-Wei Chen Ming-Hai Li Xiao-Han yu Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049China

This paper presents a neutronics design of a 10 MW ordered-pebble-bed fluoride-salt-cooled high-temperature experimental reactor. Through delicate layout, a core with ordered arranged pebble bed can be formed,which can keep core stability and meet the space requirements for thermal hydraulics and neutronics ***, objectives of the core include inherent safety and sufficient excess reactivity providing 120 effective full power days for experiments. Considering the requirements above, the reactive control system is designed to consist of 16 control rods distributed in the graphite reflector. Combining the large control rods worth about 18000–20000 pcm, molten salt drain supplementary means(-6980 to -3651 pcm) and negative temperature coefficient(-6.32 to -3.80 pcm/K) feedback of the whole core, the reactor can realize sufficient shutdown margin and safety under steady state. Besides, some main physical properties, such as reactivity control, neutron spectrum and flux, power density distribution, and reactivity coefficient,have been calculated and analyzed in this study. In addition, some special problems in molten salt coolant are also considered, including ~6Li depletion and tritium production.

关键词：中子物理学反应堆试验性高温度学习设计脉冲编码调制控制系统

Revisiting the capacity-fading mechanism of P2-type sodium layered oxide cathode materials during high-voltage cycling

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Journal of Energy Chemistry 2022年第6期31卷 16-25,I0002页

作者： Meidan Jiang Guannan Qian Xiao-Zhen Liao Zhouhong Ren Qingyu Dong Dechao Meng Guijia Cui Siqi yuan Sang-Jun Lee Tian Qin Xi Liu Yanbin Shen yu-shi he Liwei Chen Yijin Liu Linsen Li Zi-Feng Ma Department of Chemical Engineering Shanghai Electrochemical Energy Device Research Center(SEED)School of Chemistry and Chemical EngineeringFrontiers Science Center for Transformative MoleculesShanghai Jiao Tong UniversityShanghai 200240China Stanford Synchrotron Radiation Lightsource SLAC National Accelerator LaboratoryMenlo ParkCA 94025United States In-Situ Center for Physical Sciences School of Chemistry and Chemical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Suzhou Institute of Nanotech and Nanobionics(SINANO) Chinese Academy of SciencesSuzhou 215123JiangsuChina Shanghai Jiao Tong University Sichuan Research Institute Chengdu 610213SichuanChina

P2-type sodium layered oxide cathode (Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2)P2-NNMO) has attracted great attention as a promising cathode material for sodium ion batteries because of its high specific capacity. However, this material suffers from a rapid capacity fade during high-voltage cycling. Several mechanisms have been proposed to explain the capacity fade, including intragranular fracture caused by the P2-O2 phase transion, surface structural change, and irreversible lattice oxygen release. here we systematically investigated the morphological, structural, and chemical changes of P2-NNMO during high-voltage cycling using a variety of characterization techniques. It was found that the lattice distortion and crystal-plane buckling induced by the P2-O2 phase transition slowed down the Na-ion transport in the bulk and hindered the extraction of the Na ions. The sluggish kinetics was the main reason in reducing the accessible capacity while other interfacial degradation mechanisms played minor roles. Our results not only enabled a more complete understanding of the capacity-fading mechanism of P2-NNMO but also revealed the underlying correlations between lattice doping and the moderately improved cycle performance.

关键词： Phase transition Layered cathode Buckling Capacity fading mechanism Sodium-ion batteries