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High-resolution neutronics model for ^(238)Pu production in high-flux reactors

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Nuclear Science and Techniques 2024年第5期35卷 226-236页

作者： Qing-Quan Pan Qing-Fei Zhao lian-jie Wang Bang-Yang Xia Yun Cai Jin-Biao Xiong xiao-Jing Liu School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610200China

We proposed and compared three methods(filter burnup,single energy burnup,and burnup extremum analysis)to build a high-resolution neutronics model for 238Pu production in high-flux *** filter burnup and single energy burnup methods have no theoretical approximation and can achieve a spectrum resolution of up to~1 eV,thereby constructing the importance curve and yield curve of the full energy *** burnup extreme analysis method combines the importance and yield curves to consider the influence of irradiation time on production efficiency,thereby constructing extreme *** three curves,which quantify the transmutation rate of the nuclei in each energy region,are of physical significance because they have similar distributions.A high-resolution neutronics model for ^(238)Pu production was established based on these three curves,and its universality and feasibility were *** neutronics model can guide the neutron spectrum optimization and improve the yield of ^(238)Pu by up to 18.81%.The neutronics model revealed the law of nuclei transmutation in all energy regions with high spectrum resolution,thus providing theoretical support for high-flux reactor design and irradiation production of ^(238)Pu.

关键词： ^(238)Pu Neutronics model High-flux reactor Spectrum resolution Spectrum optimization

Succinylation modification:a potential therapeutic target in stroke

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Neural Regeneration Research 2024年第4期19卷 781-787页

作者： jie lian Wenwu Liu Qin Hu xiaohua Zhang Department of Neurosurgery Ren Ji HospitalShanghai Jiao Tong University School of Medicine Department of Diving and Hyperbaric Medicine Naval Medical CenterNaval Medical University

Stroke is a leading cause of mortality and disability *** cell death triggered by the compromised supply of blood oxygen and glucose is one of the major pathophysiology of strokeinduced brain *** mitochondrial energy metabolism is observed minutes after stroke and is closely associated with the progression of ***,a new type of posttranslational modification,known as lysine succinylation,has been recognized to play a significant role in mitochondrial energy metabolism after ***,the role of succinylation modification in cell metabolism after stroke and its regulation are not well *** aimed to review the effects of succinylation on energy metabolism,reactive oxygen species generation,and neuroinflammation,as well as Sirtuin 5 mediated desuccinylation after *** also highlight the potential of targeting succinylation/desuccinylation as a promising strategy for the treatment of *** succinylation level is dynamically regulated by the nonenzymatic or enzymatic transfer of a succinyl group to a protein on lysine residues and the removal of succinyl catalyzed by *** evidence has suggested that succinylation can regulate the metabolic pathway through modulating the activity or stability of metabolic ***,especially Sirtuin 5,are characterized for their desuccinylation activity and have been recognized as a critical regulator of metabolism through desuccinylating numerous metabolic *** between succinylation and desuccinylation has been implicated in the pathophysiology of *** agents that enhance the activity of Sirtuin 5 have been employed to promote desuccinylation and improve mitochondrial metabolism,and neuroprotective effects of these agents have been observed in experimental stroke ***,their therapeutic efficacy in stroke patients should be validated.

关键词： mitochondria metabolism neuroprotection sirtuin 5 stroke succinylation modification

An improved algorithm for retrieving thin sea ice thickness in the Arctic Ocean from SMOS and SMAP L-band radiometer data

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Acta Oceanologica Sinica 2024年第3期43卷 127-138页

作者： lian He Senwen Huang Fengming Hui xiao Cheng School of Geospatial Engineering and Science Sun Yat-Sen Universityand Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Key Laboratory of Comprehensive Observation of Polar Environment(Sun Yat-Sen University) Ministry of EducationZhuhai 519082China

The aim of this study was to develop an improved thin sea ice thickness(SIT)retrieval algorithm in the Arctic Ocean from the Soil Moisture Ocean Salinity and Soil Moisture Active Passive L-band radiometer *** SIT retrieval algorithm was trained using the simulated SIT from the cumulative freezing degree days model during the freeze-up period over five carefully selected regions in the Beaufort,Chukchi,East Siberian,Laptev and Kara seas and utilized the microwave polarization ratio(PR)at incidence angle of 40°.The improvements of the proposed retrieval algorithm include the correction for the sea ice concentration impact,reliable reference SIT data over different representative regions of the Arctic Ocean and the utilization of microwave polarization ratio that is independent of ice *** relationship between the SIT and PR was found to be almost stable across the five selected *** SIT retrievals were then compared to other two existing algorithms(i.e.,UH_SIT from the University of Hamburg and UB_SIT from the University of Bremen)and validated against independent SIT data obtained from moored upward looking sonars(ULS)and airborne electromagnetic(EM)induction *** results suggest that the proposed algorithm could achieve comparable accuracies to UH_SIT and UB_SIT with root mean square error(RMSE)being about 0.20 m when validating using ULS SIT data and outperformed the UH_SIT and UB_SIT with RMSE being about 0.21 m when validatng using EM SIT *** proposed algorithm can be used for thin sea ice thickness(<1.0 m)estimation in the Arctic Ocean and requires less auxiliary data in the SIT retrieval procedure which makes its implementation more practical.

关键词： Arctic sea ice sea ice thickness remote sensing Soil Moisture Active Passive(SMAP) Soil Moisture Ocean Salinity and Soil(SMOS)

Precisely modulating covalent and coordination bonds in the porous network for highly selective metal ion extraction

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Science China Chemistry 2024年第4期67卷 1039-1040页

作者： jie Li xiao Feng Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Key Laboratory of Cluster ScienceMinistry of EducationAdvanced Technology Research Institute(Jinan)Frontiers Science Center for High Energy MaterialSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China

Scandium(Sc)is recognized as a“strategic”and“critical”element by several countries,including the *** Russia,owing to its wide range of applications in high-tech fields such as superconductivity,alloys,lasers,nucle... 详细信息

关键词： alloys coordination network

Neural Dynamics for Cooperative Motion Control of Omnidirectional Mobile Manipulators in the Presence of Noises: A Distributed Approach

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IEEE/CAA Journal of Automatica Sinica 2024年第7期11卷 1605-1620页

作者： Yufeng lian Xingtian xiao Jiliang Zhang Long Jin Junzhi Yu Zhongbo Sun the Department of Control Engineering Changchun University of TechnologyChangchun 130012China IEEE the College of Information Science and Engineering Northeastern UniversityShenyang 110819 the National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China the School of Information Science and Engineering Lanzhou UniversityLanzhou 730000China the State Key Laboratory for Turbulence and Complex Systems Department of Advanced Manufacturing and RoboticsCollege of EngineeringPeking UniversityBeijing 100871China

This paper presents a distributed scheme with limited communications, aiming to achieve cooperative motion control for multiple omnidirectional mobile manipulators(MOMMs).The proposed scheme extends the existing single-agent motion control to cater to scenarios involving the cooperative operation of MOMMs. Specifically, squeeze-free cooperative load transportation is achieved for the end-effectors of MOMMs by incorporating cooperative repetitive motion planning(CRMP), while guiding each individual to desired poses. Then, the distributed scheme is formulated as a time-varying quadratic programming(QP) and solved online utilizing a noise-tolerant zeroing neural network(NTZNN). Theoretical analysis shows that the NTZNN model converges globally to the optimal solution of QP in the presence of noise. Finally, the effectiveness of the control design is demonstrated by numerical simulations and physical platform experiments.

关键词： Cooperative motion control noise-tolerant zeroing neural network(NTZNN) omnidirectional mobile manipulator(OMM) repetitive motion planning

Determination of ice jam thickness—A new approach

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Journal of Hydrodynamics 2024年第3期36卷 570-581页

作者： Jun Wang lian-sheng Sang Fei-hu Song Tie-jie Cheng Jueyi Sui School of Civil and Water Engineering Hefei University of TechnologyHefei230009China School of Engineering University of Northern British ColumbiaPrince GeorgeCanada

In winter,rivers in cold regions often experience flood disasters resulted from ice jams or ice *** of the variation of ice jam thickness and water level during an ice jammed period are not only a practical need for ice prevention to avoid disaster and plan water resource,but also essential for the development of any mathematical model for predicting the evolution of ice *** far,some equations based on the energy equation have been proposed to describe the relationship between ice jam thickness and water ***,in the derivation of these equations,the local head loss coefficient at the ice jam head and the riverbed slope factor were ***,those reported equations cannot be used to preciously describe the flow energy equation with ice jams and accurately calculate the ice jam thickness and water *** the present study,a more comprehensive theoretical model for hydraulic calculation of ice jam thickness has been derived by considering important and essential factors including riverbed slope and local head loss coefficient at the ice jam ***,based on the data collected from laboratory experiments of ice jam accumulation,the local head loss coefficient at the ice jam head has been calculated,and the empirical equation for calculating the local head loss coefficient has been established by considering flow Froude number and the ratio of ice discharge to flow *** results of this study not only provide a new reference for calculating ice jam thickness and water level,but also present a theoretical basis for accurate CFD simulation of ice jams.

关键词： Energy equation ice jam thickness local head loss coefficient ice jam head riverbed slope

Role of outdoor trees on pedestrian wind and thermal conditions around a pre-education building for sustainable energy management

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Journal of Central South University 2024年第6期31卷 2039-2053页

作者： LI xiao-jie TANG Hui-li Zhengzhou Preschool Education College Zhengzhou 450000China

Finding sustainable energy resources is essential to face the increasing energy *** are an important part of ancient architecture but are becoming rare in urban *** can control and tune the pedestrian-level wind velocity and thermal *** this study,a numerical investigation is employed to assess the role of trees planted in the windward direction of the building complex on the thermal and pedestrian wind velocity conditions around/inside a pre-education building located in the center of the *** to the previous studies(which considered only outside buildings),this work considers the effects of trees on microclimate change both inside/outside *** of different parameters including the leaf area density and number of trees,number of rows,far-field velocity magnitude,and thermal condition around the main building are *** results show that the flow velocity in the spacing between the first-row buildings is reduced by 30%-40% when the one-row trees with 2 m height are planted 15 m farther than the ***,two rows of trees are more effective in higher velocities and reduce the maximum velocity by about 50%.The investigation shows that trees also could reduce the temperature by about 1℃around the building.

关键词： sustainable management energy trees urban area thermal condition building

Realizing high initial Coulombic efficiency in manganese-based layered oxide cathodes for sodium-ion batteries via P2/O'3 biphasic structure optimization

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Rare Metals 2024年第5期43卷 2093-2102页

作者： Bo Peng Zi-Hao Zhou Ping Xuan jie Xu lian-Bo Ma School of Materials Science and Engineering Anhui University ofTechnologyMa'anshan 243002China Anhui Product Quality Supervision&Inspection Research Institute Hefei 230051China

Mn-based layered oxides are among the most promising cathode materials for sodium-ion batteries owing to the advantages of abundance,environmenta friendliness,low cost and high specific capacity.P2 and O'3 are two representative structures of Mn-based layered ***,the P2 structure containing insufficien Na generally exhibits low initial charge capacity,while O'3structure with sufficient Na delivers high initial charge capacity but poor cycle *** study prepared a multitude of Na_(x)MnO_(2)(x=0.7,0.8,0.9)cathode materials with varying P2/O'3 ratios and further investigated their electrochemical *** optimized Na_(0.8)MnO_(2) comprising 69.9 wt%O'3 and 30.1 wt%P2 phase,exhibited relatively balanced specific capacity,Coulombic efficiency and cycle ***,it achieved a high specific capacity of 128.9 mAh·g^(-1) with an initia Coulombic efficiency of 98.2%in half-cell configuration The Na_(0.8)MnO_(2)//hard carbon full cell also achieved a high specific capacity of 126.7 mAh·g^(-1) with an initia Coulombic efficiency of 98.9%.Moreover,the capacity fading mechanism was revealed by combining in-situ and ex-situ X-ray *** findings of this study provide theoretical guidance for further modification design of Mnbased layered cathodes.

关键词： Sodium-ion batteries Cathode materials Mn-based layered oxides P2/0'3 composites

New indices to balanceα-diversity against tree size inequality

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Journal of Forestry Research 2024年第1期35卷 229-237页

作者： Li Zhang Brady K.Quinn Cang Hui Meng lian Johan Gielis jie Gao Peijian Shi College of Ecology and Environment Bamboo Research InstituteNanjing Forestry University159 Longpan RoadNanjing 210037People’s Republic of China Fisheries and Oceans Canada Andrews Biological Station125 Marine Science DriveSt.AndrewsNB E5B 0E4Canada Department of Mathematical Sciences Centre for Invasion BiologyStellenbosch UniversityMatieland 7602South Africa Mathematical and Physical Biosciences African Institute for Mathematical SciencesCape Town 7945South Africa Department of Biosciences Engineering University of AntwerpB-2020 AntwerpBelgium College of Life Science Xinjiang Normal University102 Xinyi RoadUrumqi 830054People’s Republic of China

The number and composition of species in a community can be quantified withα-diversity indices,including species richness(R),Simpson’s index(D),and the Shannon-Wiener index(H΄).In forest communities,there are large variations in tree size among species and individu-als of the same species,which result in differences in eco-logical processes and ecosystem ***,tree size inequality(TSI)has been largely neglected in studies using the available diversity *** TSI in the diameter at breast height(DBH)data for each of 99920 m×20 m forest census quadrats was quantified using the Gini index(GI),a measure of the inequality of size *** generalized performance equation was used to describe the rotated and right-shifted Lorenz curve of the cumulative proportion of DBH and the cumulative proportion of number of trees per *** also examined the relationships ofα-diversity indices with the GI using correlation *** generalized performance equation effectively described the rotated and right-shifted Lorenz curve of DBH distributions,with most root-mean-square errors(990 out of 999 quadrats)being<*** were significant positive correlations between each of threeα-diversity indices(i.e.,R,D,and H’)and the ***,the total abundance of trees in each quadrat did not significantly influence the *** means that the TSI increased with increasing spe-cies ***,two new indices are proposed that can balanceα-diversity against the extent of TSI in the com-munity:(1−GI)×D,and(1−GI)×H’.These new indices were significantly correlated with the original D and H΄,and did not increase the extent of variation within each group of *** study presents a useful tool for quantifying both species diversity and the variation in tree sizes in forest communities,especially in the face of cumulative species loss under global climate change.

关键词： Diameter at breast height(DBH) Gini index Shannon-Wiener index Simpson’s index Quadrat Tree size