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Atomistic study on the microscopic mechanism of grain boundary embrittlement induced by small dense helium bubbles in iron

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Nuclear Science and Techniques 2024年第3期35卷 84-95页

作者： Lei peng Yong-Jie sun Jing-Yi Shi Yi-fei Liu Shang-Ming Chen Liu-Liu Li State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230027China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China

The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion *** order to elucidate the susceptibility of different grain boundaries(GBs)to helium-induced embrittlement,the tensile fracture processes of 10 types of GBs with and without helium bubbles in body-centered cubic(bcc)iron at the relevant service temperature of 600 K were investigated via molecular dynamics *** results indicate that in the absence of helium bubbles,the GBs studied here can be classified into two distinct categories:brittle GBs and ductile *** atomic scale analysis shows that the plastic deformation of ductile GB at high temperatures originates from complex plastic deformation mechanisms,including the Bain/Burgers path phase transition and deformation twinning,in which the Bain path phase transition is the most dominant plastic deformation ***,the presence of helium bubbles severely inhibits the plastic deformation channels of the GBs,resulting in a significant decrease in elongation at *** bubble-decorated GBs,the ultimate tensile strength increases with the increase in the misorientation ***,the coherent twin boundary∑3{112}was found to maintain relatively high fracture strength and maximum failure strain under the influence of helium bubbles.

关键词： Helium bubble Grain boundary Embrittlement Reduced activation ferritic martensitic steel Molecular dynamics Bain path

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Coupling of RANS and BEM Solvers for Simulation of Propeller Behind the Hull in Full Appended Model

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China Ocean Engineering 2024年第3期38卷 424-438页

作者： Saeed NAJAFI Mehdi POURMOSTAFA LIU peng-fei Iranian National Institute for Oceanography and Atmospheric Science(INIOAS) Tehran 14155-4781Iran Department of Maritime Engineering Amir Kabir University of TechnologyTehran 15875-4413Iran Marine Offshore and Subsea TechnologySchool of EngineeringNewcastle UniversityNewcastle upon TyneNE17RUUK

To design a propeller for ship power plant,the interaction between ship hull and propeller must be taken into *** main concern is to apply the wake effect of ship stern on the propeller *** this paper,a coupled BEM(Boundary Element Method)/RANS(Renolds-Averaged Navier−Stokes)solver is used to simulate propeller behind the hull in the self-propulsion *** motivation of this work is to develop a practical tool to design marine propulsion system without suffering long computational *** unsteady boundary element method which is also known as panel method is chosen to estimate the propeller *** wakes are treated using a time marching wake alignment ***,a RANS code coupled with VoF equation is developed to consider the ship motions and wake field effects in the problem.A coupling algorithm is developed to interchange ship wake field to the potential flow solver and propeller thrust to the RANS *** on the difference between hull resistance and the propeller thrust,a PI controller is developed to compute the propeller RPM in every time *** of the solver is carried out using the towing tank test report of a 50 m oceanography research *** factor and trust deduction coefficient are estimated ***,the wake rollup pattern of the propeller in open water is compared with the propeller in real wake field.

关键词： RANS BEM coupled method ship propeller self-propulsion wake sheet pattern

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水平井钻杆拖动酸化工艺在海上油田的应用研究

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精细与专用化学品 2024年第1期32卷 36-40页

作者：杨旭达张强赵为熊赵晨光刘洋孙鹏飞中海油服油田生产事业部天津300459

针对非均质性较强的水平井在钻完井阶段进行酸化作业,常规酸化工艺如笼统酸化、连续油管酸化等工艺都存在一定的局限性。根据目标井的实际情况,针对性地提出了采用钻杆拖动酸化工艺进行酸化。根据水平段油水分布情况,选择在油水界面以... 详细信息

针对非均质性较强的水平井在钻完井阶段进行酸化作业,常规酸化工艺如笼统酸化、连续油管酸化等工艺都存在一定的局限性。根据目标井的实际情况,针对性地提出了采用钻杆拖动酸化工艺进行酸化。根据水平段油水分布情况,选择在油水界面以下的层位挤注控水剂;根据油水界面以上层位的测井解释成果、储层孔渗分布特征等情况,优选酸化目标点,实施定点酸化。酸化作业后,静漏失速率提高为作业前的10.71倍,由酸化前的2.8bbl/h升高为30bbl/h;静漏失速率提高为作业前的7.42倍,由酸化前的6.6bbl/h升高为49bbl/h,控水及酸化效果显著。该工艺简单高效、占用平台空间小、能实现均匀酸化,具有较好的推广价值。

关键词：水平井非均质性酸化工艺钻杆拖动酸化定点酸化

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Preliminary evaluation of posterior dynamic lumbar stabilization in lumbar degenerative disease in Chinese patients

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Chinese Medical Journal 2012年第2期125卷 253-256页

作者： Jia Yu-hua sun peng-fei Shandong Univ Qilu Hosp Dept Orthopaed Jinan 250012 Shandong Peoples R China

Background There has been some controversy related to the use of the Wallis system,rather than disc fusion in the treatment of patients with degenerative spine ***,there are no reports concerning the application of this dynamic stabilization system in Chinese patients,who have a slightly different lifestyle with Western *** aim of this study was to assess the safety and efficacy of the dynamic stabilization system in the treatment of degenerative spinal diseases in Chinese *** The clinical outcomes of 20 patients with lumbar degenerative disease treated by posterior decompression with the Wallis posterior dynamic lumbar stabilization implant were *** of the patients completed the visual analogue scale and the Chinese version of the Oswestry Disability *** following radiologic parameters were measured in all patients：global lordotic angles and segmental lordotic angles （stabilized segments,above and below adjacent segments）.The range of motion was then *** Nineteen patients （95%） were available for *** mean follow-up period was （27.25±5.16） months （range 16-35 months）.The visual analogue scale decreased from 8.55±1.21 to 2.20±1.70 （P 〈0.001）,and the mean score on the Chinese version of the Oswestry Disability Index was improved from 79.58%±15.93% to 22.17%±17.24% （P 〈0.001）.No significant changes were seen in the range of motion at the stabilized segments （P=0.502） and adjacent segments （above,P=0.453; below,P=0.062）.The good to excellent result was 94.4% at the latest *** complications related to the use of the Wallis posterior dynamic lumbar stabilization *** It was found to be both easy and safe to use the Wallis posterior dynamic lumbar stabilization implant in the treatment of degenerative lumbar disease,and the early therapeutic effectiveness is *** Wallis system provides an alternative method for the treatment of lumbar degenerative disease.

关键词： lumbar degenerative disease low back pain prosthesis treatment outcome

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Local quantum Fisher information and quantum correlation in the mixed-spin Heisenberg XXZ chain

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Frontiers of physics 2024年第2期19卷 235-245页

作者： peng-fei Wei Qi Luo Huang-Qiu-Chen Wang Shao-Jie Xiong Bo Liu Zhe sun School of Physics Hangzhou Normal UniversityHangzhou 310036China Zhejiang Institute of Modern Physics and School of Physics Zhejiang UniversityHangzhou 310027China School of Information and Electrical Engineering Hangzhou City UniversityHangzhou 310015China Zhejiang Provincial Key Laboratory of Urban Wetlands and Regional Change Hangzhou 311121China

We study the local quantum Fisher information(LQFI)in the mixed-spin Heisenberg XXZ *** the maximal and minimal LQFI are studied and the former is essential to determine the accuracy of the quantum parameter estimation,the latter can be well used to characterize the discord-type quantum *** investigate the effects of the temperature and the anisotropy parameter on the maximal LQFI and thus on the accuracy of the parameter *** we make use of the minimal LQFI to study the discord-type correlations of different site *** dimensions of the subsystems cause different values of the minimal LQFI which reflects the asymmetry of the discord-type *** addition,the site pairs at different positions of the spin chains have different minimal LQFI,which reveals the influence of the surrounding spins on the bipartite quantum *** results show that the LQFI obtained through a simple calculation process provides a convenient way to investigate the discord-type correlation in high-dimensional systems.

关键词： local quantum Fisher information quantum correlation mixed-spin Heisenberg XXZ chain

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Pd single atoms cooperate with S vacancies in ZnIn_(2)S_(4) nanosheets for photocatalytic pure-water splitting

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Science China Chemistry 2024年第3期67卷 855-861页

作者： Lin sun Huiping peng fei Xue Shangheng Liu Zhiwei Hu Hongbo Geng Xiaozhi Liu Dong Su Yong Xu Xiaoqing Huang State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Guangzhou Key Laboratory of Low-Dimensional Materials and Energy Storage Devices Collaborative Innovation Center of Advanced Energy MaterialsSchool of Materials and EnergyGuangdong University of TechnologyGuangzhou 510006China Max Planck Institute for Chemical Physics of Solids Nothnitzer Strasse 40Dresden 01187Germany School of Materials Engineering Changshu Institute of TechnologyChangshu 215500China Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of SciencesBeijing 100190China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

Photocatalytic water splitting has emerged as a new frontier for converting solar energy to green H_(2) and value-added ***,great challenges still remain for developing efficient photocatalysts for pure water splitting without sacrificial *** this work,we demonstrate that doping hexagonal ZnIn_(2)S_(4)(ZIS) with Pd single atoms(Pd_(0.03)/ZIS) can serve as a highly efficient photocatalyst for pure water splitting to simultaneously produce H_(2) and H_(2)O_(2) without any sacrificial *** from aberration-corrected high-angle annular dark field scanning transmission electron microscopy,X-ray fine spectroscopy,insitu electron paramagnetic resonance and diffuse Fourier transform infrared spectroscopy reveal that doping ZIS with Pd single atoms facilitates the formation of S vacancies(S_(v)),where the photogenerated electrons can transfer to Pd single atoms,as a result of enhanced separation of electron-hole pairs and improved photocatalytic ***,Pd_(0.03)/ZIS displays a stoichiometric ratio of H_(2) and H_(2)O_(2) with the productivity of 1,037.9 and 1,021.4μmol g^(-1)h^(-1),respectively,which has largely outperformed pure ZIS and other reported catalysts for pure water *** work provides an efficient photocatalyst for water splitting to produce H_(2) and H_(2)O_(2),which may attract rapid interest in materials science,chemistry,and heterogeneous catalysis.

关键词： ZnIn_(2)S_(4) Pd single atom S vacancy pure water splitting H_(2)O_(2)

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Catalytically generated noncovalent ammonium dienolate:a versatile platform for the development of organocatalytic asymmetric cascade reactions

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Science China Chemistry 2024年第8期67卷 2524-2546页

作者： Jun-Bing Lin Dong-Sheng Ji peng-fei Xu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China Shaanxi Key Laboratory of Chemical Reaction Engineering College of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000China

Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.

关键词： organocatalysis asymmetric catalysis ammonium dienolate cascade reaction difunctionalization

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Existence of Positive Solutions to a Fractional-Kirchhoff System

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 225-240页

作者： peng-fei Li Jun-hui Xie Dan Mu School of Mathematics and Statistics Hubei Minzu UniversityEnshi445000China

LetΩbe a bounded smooth domain in RN(N≥3).Assuming that 00 are constants,we consider the existence results for positive solutions of a class of fractional elliptic system below,{(a+b[u]^(2)_(s))(-Δ)^(s)u=vp+h_(1)(x,u,v,▽u,▽v),x∈Ω,(-Δ)^(s)v=u^(q)+h_(2)(x,u,▽,▽u,▽v),x∈Q,u,v>0,x∈Ω,u=v=0,x∈RN\Ω.Under some assumptions of hi(x,u,v,▽u,▽v)(i=1,2),we get a priori bounds of the positive solutions to the problem(1.1)by the blow-up methods and rescaling *** on these estimates and degree theory,we establish the existence of positive solutions to problem(1.1).

关键词： fractional-Kirchhoff system a priori bounds degree theory positive solution

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Evaluation of water management on arsenic methylation and volatilization in arsenic-contaminated soils strengthened by bioaugmentation and biostimulation

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Journal of Environmental Sciences 2024年第3期137卷 515-526页

作者： peng Chen Yi Liu Guo-Xin sun State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhan 430074China University of Chinese Academy of Sciences Beijing 100049China

Arsenic(As) fate in paddy fields has been one of the most significant current issues due to the strong As accumulation potential of rice plants under fooded conditions. However,no attempt was done to explore As methylation and volatilization under non-fooded conditions. Herein, we investigated the effects of water management on As methylation and volatilization in three arsenic-contaminated soils enhanced by biostimulation with strawderived organic matter and bioaugmentation with genetic engineered Pseudomonas putida KT2440(GE P. putida). Under fooded conditions, the application of biochar(BC), rice straw(RS)and their combination(BC+RS) increased total As in porewater. However, these effects were greatly attenuated under non-fooded conditions. Compared with RS amendment alone, the combination of GE P. putida and RS further promoted the As methylation and volatilization,and the promotion percentage under non-fooded conditions were significantly higher than that under fooded conditions. The combined GE P. putida and RS showed the highest efficiency in As methylation(88 μg/L) and volatilization(415.4 μg/(kg·year)) in the non-fooded soil with moderate As contamination. Finally, stepwise multiple linear regression analysis presented that methylated As, DOC and p H in porewater were the most important factors contributing to As volatilization. Overall, our findings suggest that combination of bioaugmentation with GE P. putida and biostimulation with RS/BC+RS is a potential strategy for bioremediation of arsenic-contaminated soils by enhancing As methylation and volatilization under non-fooded conditions.

关键词： Arsenic methylation Arsenic volatilization Water management Straw incorporation Bioaugmentation

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材料成型专业深化改革与教学实践研究

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铸造设备与工艺 2024年第2期 70-74页

作者：朱永长叶丹王红英贾克明夏春艳孙鹏飞董海佳木斯大学材料科学与工程学院黑龙江佳木斯154007

本文研究了材料成型专业的深化改革与教学实践,旨在提高该领域的教学质量和方法创新。通过对当前材料成型专业教育的问题分析,提出了针对性的改革措施和实践方法。内容从课程设置、实践环节、教学方法、教学资源整合和教师素质提升等多... 详细信息

本文研究了材料成型专业的深化改革与教学实践,旨在提高该领域的教学质量和方法创新。通过对当前材料成型专业教育的问题分析,提出了针对性的改革措施和实践方法。内容从课程设置、实践环节、教学方法、教学资源整合和教师素质提升等多个方面进行了深入探讨,并给出了针对性的改革措施和实践方法。研究成果为材料成型专业的深化改革与实践提供了新的思路和方法。改革措施和实践方法不仅可以提高学生的实践能力和创新能力,还可以为材料成型行业的发展提供更加优秀的人才支持。本文的研究内容可以为其他相关专业及领域的深化改革与实践提供参考和借鉴。

关键词：材料成型专业深化改革教学资源教师素质

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