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Frontiers of Chemical Science and Engineering 2023年第9期17卷 1311-1319页

作者： fan Sun Huijiang Huang Wei Liu Lu Wang Yan Xu Yujun Zhao Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Center of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin300072China

A reconstructed Cu-ZnO catalyst with improved stability was fabricated by organic acid treatment method for the liquid-phase hydrogenation of dimethyl succinate to 1,*** to the characterization results of the fresh Cu-ZnO and reconstructed Cu-ZnO,three different forms of ZnO were suggested to be presented on the catalysts:ZnO having strong interaction with Cu species,ZnO that weakly interacted with Cu species and isolated *** first form of ZnO was believed to be beneficial to the formation of efficient active site Cu^(+),while the latter two forms of ZnO took the main responsibility for the deactivation of Cu-ZnO catalysts in the liquid-phase hydrogenation of *** reconstruction of the Cu-ZnO catalyst by the organic acid treatment method resulted in a new Cu-ZnO catalyst with more Cu^(+)and less ZnO species that leads to ***,the deactivation mechanism of Cu-ZnO catalysts in liquid-phase diester hydrogenation in continuous flow system was proposed:the deposition of the polyesters on the catalysts via transesterification catalyzed by weakly interacted ZnO and isolated ZnO leads to the *** results provided meaningful instructions for designing highly efficient Cu-Zn catalysts for similar ester hydrogenation systems.

关键词： liquid phase hydgonenation Cu-ZnO deactivation mechanism 1,4-butanediol diester

Kinematic,Workspace and Force Analysis of A Five-DOF Hybrid Manipulator R(2RPR)R/SP+RR

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Chinese Journal of Mechanical Engineering 2022年第5期35卷 232-243页

作者： Yundou Xu fan Yang Youen Mei Dongsheng Zhang Yulin Zhou Yongsheng Zhao Laboratory of Parallel Robot and Mechatronic System of Hebei Province Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of National Education Yanshan UniversityQinhuangdao 006004China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China Tencent Robotics X Tencent HoldingsShenzhen 518057China

In the present study,the over-constrained hybrid manipulator R(2RPR)R/SP+RR is considered as the research *** this paper,kinematics of the hybrid manipulator,including the forward and inverse position,are ***,the workspace is checked based on the inverse position solution to evaluate whether the workspace of the hybrid manipulator meets the requirements,and the actual workspace of the hybrid robot is *** that,the force analysis of the over-constrained parallel mechanism is carried out,and an ADAMS-ANSYS rigid-flexible hybrid body model is established to verify the *** on the obtained results from the force analysis,the manipulator structure is ***,the structure optimization is carried out to improve the robot ***,calibration and workspace verification experiments are performed on the prototype,cutting experiment of an S-shaped aluminum alloy workpiece is completed,and the experiment verifies the machining ability of the *** work conducts kinematics,workspace,force analyses,structural optimization design and experiments on the over-constrained hybrid manipulator R(2RPR)R/SP+RR,providing design basis and technical support for the development of the novel hybrid manipulator in practical engineering.

关键词： Hybrid manipulator Over-constrained Kinematic analysis Stiffness analysis

Modeling and analysis of oil frictional loss in wet-type permanent magnet synchronous motor for aerospace electro-hydrostatic actuator

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Chinese Journal of Aeronautics 2023年第11期36卷 328-341页

作者： Jinquan XU Wenbo JIN Hong GUO Tian YU Wenhu fan Zongxia JIAO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315800China Research Institute for Frontier Science Beihang UniversityBeijing 100191China

To improve the power density and simplify the seal structure,the Wet-Type Permanent Magnet Synchronous Motor(WTPMSM)technique has been applied to aerospace Electro-Hydrostatic Actuators(EHA).In a WTPMSM,the stator and the rotor are both immersed in the aviation hydraulic *** the heat dissipation performance of the WTPMSM can be enhanced,the aviation hydraulic oil will cost an extra oil frictional loss in the narrow airgap of the *** paper proposes an accurate oil frictional loss model for the WTPMSM,in which the wide speed range(0–20 kr/min)and the narrowness of the airgap(0.5–1.5 mm)are its ***,the mechanism of the oil frictional loss in the airgap of the WTPMSM is *** an accurate oil frictional loss model is proposed considering the nonlinear influence caused by the Taylor ***,the influence of motor dimensions on oil frictional loss is ***,the proposed oil frictional loss model is verified by experiments,which provides a guideline for engineers to follow in the WTPMSM design.

关键词： Electro-hydrostatic actuator Motor dimensions Oil frictional loss Taylor vortex Wet-type permanent magnet synchronous motor

Identification of reference genes provides functional insights into meiotic recombination suppressors in Gerbera hybrida

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Horticultural Plant Journal 2022年第1期8卷 123-132页

作者： fan Li Ying Cheng Lulin Ma Shenchong Li Jihua Wang Floriculture Research Institute Yunnan Academy of Agricultural SciencesNational Engineering Research Center for Ornamental HorticultureKey Laboratory for Flower Breeding of Yunnan ProvinceKunming 650200China School of Agriculture Yunnan UniversityKunming 650504China

Gerbera Hybrida is one of the important cut flowers across the *** novel traits are the primarily market requirements and the breeding targets,mainly determined by the degree of genetic variation after ***,meiotic recombination is highly conserved in most eukaryotes which suppressed the crossover formation and limited the genetic ***,several meiotic recombination suppressors have been identified and characterized in plants,whereas it remains elusive in *** order to characterize the expression patterns of these suppressors in ***,20 candidate reference genes were identified from the transcriptome datasets of ***,and their expression stabilities during plant development were evaluated by geNorm,NormFinder and *** the most stable reference genes were variable in different softwares,comprehensive ranking revealed that PGK2 was the most stable reference gene and GAPDH was the most unstable *** expression patterns of fanCM,FIGL1,RECQ4,RM1,and FLIP further validated that PGK2 was suitable for normalization of gene *** study identified a reliable reference gene for gene expression during meiotic recombination,and provided functional insights into meiotic recombination suppressors in ***.

关键词： erbera hybrida Reference gene Gene expression Meiotic recombination suppressor

GA signaling protein LsRGL1 interacts with the abscisic acid signaling-related gene LsWRKY70 to affect the bolting of leaf lettuce

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Horticulture Research 2023年第5期10卷 165-177页

作者： Li Chen Chaojie Liu Jinghong Hao Shuangxi fan Yingyan Han Department of Plant Science and Technology Beijing Key Laboratory of New Technology in Agricultural ApplicationNational Demonstration Center for Experimental Plant Production EducationBeijing University of AgricultureBeijing 102206China

A variety of endogenous hormone signals,developmental cues,and environmental stressors can trigger and promote leaf lettuce *** such factor is gibberellin(GA),which has been linked to ***,the signaling pathways and the mechanisms that regulate the process have not been discussed in full *** clarify the potential role of GAs in leaf lettuce,significant enrichment of GA pathway genes was found by RNA-seq,among which the LsRGL1 gene was considered *** overexpression of LsRGL1,a noticeable inhibition of leaf lettuce bolting was observed,whereas its knockdown by RNA interference led to an increase in *** situ hybridization analysis indicated a significant accumulation of LsRGL1 in the stem tip cells of overexpressing *** lettuce plants stably expressing LsRGL1 were examined concerning differentially expressed genes through RNA-seq analysis,and the data indicated enhanced enrichment of these genes in the‘plant hormone signal transduction’and‘phenylpropanoid biosynthesis’***,significant changes in LsWRKY70 gene expression were identified in COG(Clusters of Orthologous Groups)functional *** results of yeast one-hybrid,β-glucuronidase(GUS),and biolayer interferometry(BLI)experiments showed that LsRGL1 proteins directly bind to the LsWRKY70 *** LsWRKY70 by virus-induced gene silencing(VIGS)can delay bolting,regulate the expression of endogenous hormones,abscisic acid(ABA)-linked genes,and flowering genes,and improve the nutritional quality of leaf *** results strongly associate the positive regulation of bolting with LsWRKY70 by identifying its vital functions in the GA-mediated signaling *** data obtained in this research are invaluable for further experiments concerning the development and growth of leaf lettuce.

关键词： endogenous concerning expressing

Alleviated photoinhibition on nitrification in the Indian Sector of the Southern Ocean

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Acta Oceanologica Sinica 2024年第7期43卷 52-69页

作者： Lingfang fan Min Chen Zifei Yang Minfang Zheng Yusheng Qiu College of Ocean and Earth Sciences Xiamen UniversityXiamen 361102China

Nitrification,a central process in the marine nitrogen cycle,produces regenerated nitrate in the euphotic zone and emits N_(2)O,a potent greenhouse gas as a *** regulatory mechanisms of nitrification in the Southern Ocean,which is a critical region for CO_(2)sequestration and radiative benefits,remain poorly ***,we investigated the in situ and dark nitrification rates in the upper 500 m and conducted substrate kinetics experiments across the Indian Sector in the Cosmonaut and Cooperation seas in the late austral *** findings indicate that light inhibition of nitrification decreases exponentially with depth,exhibiting a light threshold of 0.53%photosynthetically active radiation.A positive relationship between dark nitrification and apparent oxygen utilization suggests a dependence on substrate availability from primary ***,an increased NH_(4)^(+) supply can act as a buffer against photo-inhibitory ***,substrate affinity(α)increases with depth and transitions from light to dark,decreases with increasing ambient NH_(4)^(+)and exhibits a latitudinal distribution,reflecting substrate utilization *** also reveal that upwelling in Circumpolar Deep Water(CDW)stimulates nitrification through the introduction of potentially higher iron and deep diverse nitrifying microorganisms with higherα.We conclude that although light is the primary limiting factor for nitrification in summer,coupling between substrate availability and CDW upwelling can overcome this limitation,thereby alleviating photoinhibition by up to 45%±5.3%.

关键词： nitrification light inhibition substrate affinity circumpolar deep water(CDW)upwelling the Southern Ocean

ANISOTROPIC EQ^(ROT)_(1) FINITE ELEMENT APPROXIMATION FOR A MULTI-TERM TIME-FRACTIONAL MIXED SUB-DIFFUSION AND DIFFUSION-WAVE EQUATION

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Journal of Computational Mathematics 2023年第3期41卷 458-481页

作者： Huijun fan Yanmin Zhao Fenling Wang Yanhua Shi Fawang Liu School of Science Xuchang UniversityXuchang 461000China School of Mathematics and Statistics Zhengzhou UniversityZhengzhou 450001China Henan Joint International Research Laboratory of High Performance Computation for Complex Systems Xuchang 461000China School of Mathematical Sciences Queensland University of TechnologyBrisbane QLD 4001Australia School of Mathematics and Statistics Fuzhou UniversityFuzhou 350108China

By employing EQ^(ROT)_(1) nonconforming finite element,the numerical approximation is presented for multi-term time-fractional mixed sub-diffusion and diffusion-wave equation on anisotropic *** with the multi-term time-fractional sub-diffusion equation or diffusion-wave equation,the mixed case contains a special time-space coupled derivative,which leads to many difficulties in numerical ***,a fully discrete scheme is established by using nonconforming finite element method(FEM)in spatial direction and L1 approximation coupled with Crank-Nicolson(L1-CN)scheme in temporal ***,the fully discrete scheme is proved to be unconditional ***,convergence and superclose results are derived by using the properties of EQ^(ROT)_(1) nonconforming finite ***'s more,the global superconvergence is obtained via the interpolation postprocessing ***,several numerical results are provided to demonstrate the theoretical analysis on anisotropic meshes.

关键词： Multi-term time-fractional mixed sub-diffusion and diffusion-wave equation Nonconforming FEM L1-CN scheme Anisotropic meshes Convergence and superconvergence

Small tracking error correction for moving targets of intelligent electro-optical detection systems

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Frontiers of Mechanical Engineering 2024年第2期19卷 29-44页

作者： Cheng SHEN Zhijie WEN Wenliang ZHU Dapeng fan Mingyuan LING College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China

Small tracking error correction for electro-optical systems is essential to improve the tracking precision of future mechanical and defense *** threats,such as“low,slow,and small(LSS)”moving targets,pose increasing challenges to *** core goal of this work is to address the issues,such as small tracking error correction and aiming control,of electro-optical detection systems by using mechatronics drive modeling,composite velocity–image stability control,and improved interpolation filter design.A tracking controller delay prediction method for moving targets is proposed based on the Euler transformation model of a two-axis,two-gimbal cantilever beam coaxial *** tracking error formation is analyzed in detail to reveal the scientific mechanism of composite control between the tracking controller’s feedback and the motor’s velocity–stability *** improved segmental interpolation filtering algorithm is established by combining line of sight(LOS)position correction and multivariable typical tracking fault ***,a platform with 2 degrees of freedom is used to test the *** LSS moving target shooting object with a tracking distance of S=100 m,target board area of A=1 m^(2),and target linear velocity of v=5 m/s is *** show that the optimal method’s distribution probability of the tracking error in a circle with a radius of 1 mrad is 66.7%,and that of the traditional method is 41.6%.Compared with the LOS shooting accuracy of the traditional method,the LOS shooting accuracy of the optimized method is improved by 37.6%.

关键词： electro-optical detection system small tracking error moving target visual servo aiming contro

Aboveground biomass and its spatial distribution pattern of herbaceous marsh vegetation in China

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Science China Earth Sciences 2021年第7期64卷 1115-1125页

作者： Xiangjin SHEN Ming JIANG Xianguo LU Xingtu LIU Bo LIU Jiaqi ZHANG Xianwei WANG Shouzheng TONG Guangchun lei Shengzhong WANG Chuan TONG Hangqing fan Kun TIAN Xiaolong WANG Yuanman HU Yonghong XIE Muyuan MA Shuwen ZHANG chunxiang CAO Zhichen WANG Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China Key Laboratory of Ecological Protection in the Yellow'River Basin of National Forestry and Grassland Administration School of Ecology1 andConservationBeijing Forestry UniversityBeijing 100083China School of Geographical Sciences Northeast Normal UniversityChangchun 130024China School of Geography Fujian Normal UniversityFuzhou 350007China Guangxi Mangrove Research Center Guangxi Academy of SciencesBeihai 536000China National Plateau Wetlands Research Center Southwest Forestry UniversityKunming 650224China Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China Institute of Applied Ecology Chinese Academy of SciencesShenyang 110016China Key Laboratory of Agro-ecological Processes in Subtropical Region Institute of Subtropical AgricultureChinese Academy of SciencesChangsha 410125China Institute of Wetland Research Chinese Academy of ForestryBeijing 100091China State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100101China Academy of Inventory and Planning National Forestry and Grassland AdministrationBeijing 100714China

Herbaceous marsh is the most widely distributed type of marsh wetland ecosystem,and has important ecological functions such as water conservation,climate regulation,carbon storage and fixation,and sheltering rare *** carbon sequestration function of herbaceous marsh plays a key role in slowing climate warming and maintaining regional environmental *** biomass is an important index reflecting the carbon sequestration capacity of *** the biomass of marsh vegetation can provide a scientific basis for estimating the carbon storage and carbon sequestration capacity of *** on field survey data of aboveground biomass of herbaceous marsh vegetation and the distribution data set of marsh in China,we analyzed the aboveground biomass and its spatial distribution pattern of herbaceous marsh on a national scale for the first *** results showed that in China the total area of herbaceous marsh was 9.7×10^(4) km^(2),the average density of aboveground biomass of herbaceous marsh vegetation was 227.5±23.0 g C m-2(95%confidence interval,the same below),and the total aboveground biomass was 22.2±2.2 Tg C(1 Tg=1012 g).The aboveground biomass density of herbaceous marsh vegetation is generally low in Northeast China and the Tibetan Plateau,and high in central North China and coastal regions in *** different marsh distribution regions of China,the average biomass density of herbaceous marsh vegetation from small to large was as follows:temperate humid and semi-humid marsh region(182.3±49.3 g C m^(-2))

关键词： Herbaceous marsh Wetland Vegetation Aboveground biomass Spatial distribution China

A Research on Problems for Sustainable Development of Mining Cities in China

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Chinese Journal of Population,Resources and Environment 2010年第3期8卷 29-37页

作者： Sun Wei fan Jie Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China Key Laboratory of Regional Sustainable Development Modeling CAS Beijing 100101 China

As a significant issue, mining cities, especially the resource-exhausted mining cities have already been given intensive attention by academia and government. This article discusses the intrinsic and extrinsic reasons for problems of the mining cities from the perspective of sustainable development, quantitatively analyzes the economic benefit of the mining cities with statistical data, and presents the strategies and measures for sustainable development of the mining cities based on the theoretical discus- sion and empirical study of different types of mining cities. The research shows that: (1) the conflict between the mining cities and the mining enterprises which has been incorrectly dealt with for a long time is the primary reason for the problems of the mining cities. More seriously, the development gap between mining cities and non-mining cities is becoming larger than ever before, due to the domestic and international competition. (2) As a whole, the economic development level of the mining cities is lower than the average level of countrywide cities. The economic benefit of the mining cities is increasing owing to the economic scale, and the economic situations of oil-mining cites and iron-mining cites are relatively better than those of other types of mining cities. (3) The prerequisite of sustainable development of the mining cities is the realization of the transformation of capital superiority so as to promote non-mining economy and substitute the mining economy step by step.

关键词： mining city sustainable development city competitiveness