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Method for the fruit tree recognition and navigation in complex environment of an agricultural robot

International Journal of Agricultural and Biological Engineering 2024年第2期17卷 221-229页

作者： Xiaolin Xie Yuchao Li Lijun zhao xin Jin Shengsheng Wang Xiaobing Han College of Agricultural Equipment Engineering Henan University of Science and TechnologyLuoyang 471003HenanChina Collaborative Innovation Center of Machinery Equipment Advanced Manufacturing of Henan Province Luoyang 471003HenanChina Longmen Laboratory Luoyang 471003HenanChina College of Intelligent and Manufacturing Engineering Chongqing University of Arts and SciencesChongqing 402160China

To realize the visual navigation of agricultural robots in the complex environment of orchards,this study proposed a method for fruit tree recognition and navigation based on *** YOLOv5s model was selected and trained to identify the trunks of the left and right rows of fruit trees;the quadratic curve was fitted to the bottom center of the fruit tree recognition box,and the identified fruit trees we.e divided into left and right columns by using the extreme value point of the quadratic curve to obtain the left and right rows of fruit trees;the straight-line equation of the left and right fruit tree rows was further solved,the median line of the two straight lines was taken as the expected navigation path of the robot,and the path tracing navigation experiment was carried out by using the improved LQR control *** experimental results show that under the guidance of the machine vision system and guided by the improved LQR control algorithm,the lateral error and heading error can converge quickly to the desired navigation path in the four initial states of[0 m,−0.34 rad],[0.10 m,0.34 rad],[0.15 m,0 rad]and[0.20 m,−0.34 rad].When the initial speed was 0.5 m/s,the average lateral error was 0.059 m and the average heading error was 0.2787 rad for the navigation trials in the four different initial *** average driving was 5.3 m into the steady state,the average value of steady state lateral error was 0.0102 m,the average value of steady state heading error was 0.0253 rad,and the average relative error of the robot driving along the desired navigation path was 4.6%.The results indicate that the navigation algorithm proposed in this study has good robustness,meets the operational requirements of robot autonomous navigation in orchard environment,and improves the reliability of robot driving in orchard.

关键词： fruit tree recognition visual navigation YOLOv5 complex environments orchards

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Relationship betwe.n physical activity and specific working memory indicators of depressive symptoms in university students

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World Journal of Psychiatry 2024年第1期14卷 148-158页

作者： Qun zhao xing Wang Shu-Fan Li Peng Wang Xiang Wang xin xin Suo-Wang Yin zhao-Song Yin Li-Juan Mao School of Physical Education Shanghai University of SportShanghai 200438China Department of Physical Education Donghua UniversityShanghai 201620China

BACKGROUND The detection rate of depression among university students has been increasing in recent years,becoming one of the main psychological diseases that endangers their physical and mental *** to statistics,self-harm and suicide,for which there is no effective intervention,are the second leading causes of *** To explore the relationship betwe.n different elements and levels of physical activity and college students’depression-symptom-specific working memory *** Of 143 college students we.e analyzed using the Beck Depression Self-Rating Scale,the Physical Activity Rating Scale,and the Working Memory *** There was a significant difference betwe.n college students with depressive symptoms and healthy college students in completing verbal and spatial working memory(SWM)tasks correctly(all Pwe.e significantly and positively correlated with the correct rate of the verbal working memory task(r=0.166)and the correct rate of the SWM task(r=0.210)(all Pwe.e significant differences in the correct rates of verbal and SWM tasks according to different exercise intensities(all P0.05).CONCLUSION An increase in physical exercise among college students,particularly medium-and high-intensity exercise and exercise of 30 min or more,can improve the correct rate of completing working memory tasks.

关键词： Physical activity Depression symptoms University students Working memory

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Solid-state lithium-ion batteries for grid energy storage:opportunities and challenges

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Science China Chemistry 2024年第1期67卷 43-66页

作者： xin Chang Yu-Ming zhao Boheng Yuan Min Fan Qinghai Meng Yu-Guo Guo Li-Jun Wan CAS Key Laboratory of Molecular Nanostructure and Nanotechnology CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China

The energy crisis and environmental pollution drive more attention to the development and utilization of renewable *** the capricious nature of renewable energy resource,it has difficulty supplying electricity directly to consumers stably and efficiently,which calls for energy storage systems to collect energy and release electricity at peak *** to their flexible powe. and energy,quick response,and high energy conversion efficiency,lithium-ion batteries stand out among multiple energy storage technologies and are rapidly deployed in the *** superior performance and ensuring the safety of energy storage systems,intrinsically safe solid-state electrolytes are expected as an ideal alternative to liquid *** this review,we.systematically evaluate the priorities and issues of traditional lithium-ion batteries in grid energy *** lithium-ion batteries containing liquid electrolytes,solid-state lithium-ion batteries have the potential to play a more significant role in grid energy *** challenges of developing solid-state lithium-ion batteries,such as low ionic conductivity of the electrolyte,unstable electrode/electrolyte interface,and complicated fabrication process,are discussed in ***,the safety of solid-state lithium-ion batteries is *** the obtained insights,inspiring prospects for solid-state lithium-ion batteries in grid energy storage are depicted.

关键词： lithium-ion batteries grid energy storage solid-state electrolytes interface stability

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A novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite oxide with surface doping of Y and its application in Pd-only three-way catalyst

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Rare Metals 2024年第2期43卷 749-757页

作者： Zheng zhao we.-xin zhao Yong-Qi Zhang Mei-Sheng Cui Yong-Ke Hou Dong-Ming Chen Juan-Yu Yang Zong-Yu Feng Xiao-we. Huang National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.GRINM Group Corporation LimitedBeijing100088China Griem Hi-Tech Co.Ltd. Langfang065000China Rare Earth Functional Materials(Xiong’an)Innovation Venter Co.Ltd. Baoding071700China

The ceria-zirconia compound oxide-supported noble metal Pd(Pd@CZ)is widely used in three-way ***,the surface structure of CZ plays an important role in catalytic activity of ***,how to regulate the surface structure of CZ and clarify the structure–activity relationship is still a *** this paper,a strategy is proposed to develop high activity Pd@CZ nanocatalysts by tuning Y doping sites in *** precipitate-deposition method is developed to prepare the novel Ce_(0.485)Zr_(0.485)Y_(0.03)O_(2) composite with surface doping of Y(CZ-Y-S).In addition,the Pd@CZ-Y-S(Pd supported on CZ-Y-S)exhibits superior catalytic activity for HC,CO,and NO oxide,wherein,for CO and C_(3)H_(6) oxidation,the low-temperature activity of Pd@CZ-Y-S is still 20%higher than that of Pd@CZ-Y-B(Y bulk doping)and commercial Pd@CZ after 1000℃/4 h *** effect mechanism is further studied by density functional theory(DFT)*** with Pd@CZ-Y-B,Pd@CZ-Y-S shows the lowe. CO oxide reaction energy barriers due to the we.ker adsorption strength of *** Y surface doping strategy could provide valuable insights for the development of highly efficient Pd@CZ catalyst with extensive applications.

关键词： Rare earth Ceria-zirconia-supported Pd Surface doping Experiment and theory Catalytic application

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Improvement for creep strength of a second-generation single crystal superalloy by design of heat treatments

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Rare Metals 2024年第1期43卷 342-350页

作者： Wan-Shun Xia xin-Bao zhao Jia-Chen Xu Quan-zhao Yue Qing-Qing Ding Huan-Chang Duan Yue-Feng Gu Hong-Bin Bei Ze Zhang Institute of Superalloys Science and Technology School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Silicon and Advanced Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

Design of heat treatments is related to the key technology for development of nickel-based single crystal superalloys(Ni-SXs). Based on the full understanding of the solidification characteristics, this work applies optimization design of heat treatments for a second-generation Ni-SX. Microstructure evolution and creep properties are compared in the material under conventional/standard(Std.) and optimized(Opt.) treatments. For the Std. sample,strong dendritic segregations determine inconsistent microstructure evolution in the dendritic(D) and interdendritic region(ID), while the latter serves as we.k area to have the prior microcrack initiation, damaging overall performance of the alloy. The Opt. treatment applies higher homogenization temperature, leading to overall reduced segregations, while not inducing incipient melting. A lowe. temperature of first-step ageing is used to lowe. the size ofγ'particles. These help to form the more uniform microstructure in dendritic and interdendritic region and relieve the inconsistent microstructure evolution. The balanced local strength makes ID no longer as the we.k area,thus restricting microcrack initiation. Great improvement of high temperature and low stress property is obtained by this progress, leading to the pronounced increase of creep rupture life under 1100 °C/140 MPa.

关键词： Single crystal superalloy Heat treatment Segregation Solidification Creep property

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Effect of Artificial Cooling Extrusion on Microstructure and Mechanical Properties of Mg–Zn–Y Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1115-1127页

作者： Qi-Yu Liao Da-Zhi zhao Qi-Chi Le we.-xin Hu Yan-Chao Jiang we.-Yang Zhou Liang Ren Dan-Dan Li zhao-Yang Yin School of Materials Science and Engineering Northeastern UniversityShenyang110819China Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang110819China Key Laboratory of Lightwe.ght Structural Materials Liaoning ProvinceNortheastern UniversityShenyang110819China Baotou Research Institute of Rare Earths Baotou014000China

Microstructure and mechanical properties of Mg–Zn–Y alloys with different Zn/Y atomic ratios with or without artificial cooling (AC) extrusion we.e systematically investigated in this work. The results show that bimodal microstructure consisting of submicron dynamic recrystallized (DRXed) grains with high fraction of low-angle grain boundaries (LAGBs) and elongated unDRXed grains was formed in Mg_(98.7)Zn_(1)Y_(0.3) alloy with AC extrusion. The AC process effectively limits the growth of precipitated phases, and large amount of nanoscale precipitates we.e dynamically precipitated during the extrusion process. AC extrusion could effectually refine the lamellar 14H LPSO phases and inhibit the transition from stacking faults to LSPO phases in Mg_(98)Zn_(1)Y_(1) alloy and the narrow LPSO phase in Mg_(98)Zn_(1)Y_(1)-AC alloy which could promote the nucleation of DRXed grains. The AC extrusion significantly improves the strength of Mg–Zn–Y alloys. Owing to AC extrusion, the strength improvement of Mg_(98.7)Zn_(1)Y_(0.3) alloy is mainly attributed to fine grain strengthening, dislocation strengthening, and nano-phases precipitation strengthening. After AC process, more fine grains and nano-phases jointly strengthen the Mg_(98)Zn_(1)Y_(1) alloy. The Mg_(98)Zn_(1)Y_(1) alloy obtains optimal mechanical properties after extrusion at 623 K, with ultimate tensile strength (UTS) of 406 MPa, yield strength (YS) of 388 MPa, and elongation (EL) of 5.6%.

关键词： Mg-Zn-Y Artificial cooling Extrusion Microstructure Mechanical properties

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Bioinspired Hollow Mesoporous Silica Nanoparticles Coating on Titanium Alloy with Hierarchical Structure for Modulating Cellular Functions

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Journal of Bionic Engineering 2024年第3期21卷 1427-1441页

作者： Jiaxin Zhang He Liu Jincheng Wang Jing Shang Mingwe. Xu Xiujie Zhu Chao Xu Haotian Bai xin zhao Orthopedic Institute of Jilin Province Orthopedic Medical CenterThe Second Hospital of Jilin UniversityChangchun130041China Key Laboratory of Bionic Engineering(Ministry of Education) Jilin UniversityChangchun130025China Institute of Structured and Architected Materials Liaoning Academy of MaterialsShenyang110167China

3D-printed Porous Titanium Alloy Implants(pTi),owing to their biologically inertness and relatively smooth surface morphology,adversely affect the biological functions of surrounding *** address the challenges,constructing a bioinspired interface that mimics the hierarchical structure of bone tissue can enhance the cellular functions of *** this context,Hollow Mesoporous Silica Nanoparticles(HMSNs),renowned for their unique physicochemical properties and superior biocompatibility,offer a promising direction for this *** this research,the initially synthesized HMSNs we.e used to construct a“hollow-mesoporous-macroporous”hierarchical bioinspired coating on the pTi surface through the Layer-by-Layer ***,diverse morphologies of coatings we.e established by adjusting the deposition strategy of PDDA/HMSNs on the pTi surface(pTi-HMSN-2,pTi-HMSN-4,pTi-HMSN-6).A range of techniques we.e employed to investigate the physicochemical properties and regulation of cellular biological functions of the diverse HMSN coating ***,the pTi-HMSN-4 and pTi-HMSN-6 groups exhibited the uniform coatings,leading to a substantial enhancement in surface roughness and ***,the coating constructed strategy of pTi-HMSN-4 possessed commendable *** on the aforementioned findings,both pTi-HMSN-4 and pTi-HMSN-6 facilitated the adhesion,spreading,and pseudopodia extension of BMSCs,which led to a notable upsurge in the expression levels of vinculin protein in *** analysis indicates that the coating,when PDDA/HMSNs are deposited four times,possesses favorable overall *** research will provide a solid theoretical basis for the translation of HMSN bioinspired coatings for orthopedic implants.

关键词： Hollow mesoporous silica nanoparticles Bioinspired coating Titanium alloy Hierarchical structure Cellular functions

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NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)solid solution red phosphors:Microstructure variation and luminescence enhancement induced by Zn^(2+)-doping

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Journal of Rare Earths 2024年第7期42卷 1224-1232,I0001页

作者： Yu Gao Jiayang Liao Mingyi Zhang Qingmei Tang Ting Zhou Mengjiao Liu Yan zhao xin Lai Daojiang Gao College of Chemistry and Materials Science Sichuan Normal UniversityChengdu610066China

Red phosphor is an important component of the phosphor-converted white light-emitting diodes(pcWLEDs).The development of the novel red phosphor with excellent luminescence properties is of great significance for high performance *** this study,NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)red phosphors with excellent luminescence properties we.e successfully synthesized and systematically *** results show that the Zn^(2+)-doping concentration has significant effect on the microstructures and luminescence properties of the NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)*** NaGd_(0.4)Eu_(0.6)Mg_(1-x)ZnxWO_(6)(0≤x≤0.7)samples are we.l crystallized pure solid solution sub-microcrystals,whereas the phase purity gradually decreases at 0.7we. CCT,and chromaticity coordinate close to the pure white *** developed NaGd_(0.4)Eu_(0.6)Mg_(1-x)Zn_(x)WO_(6)phosphors have potential application in lighting and *** work can offer an effective strategy for boosting luminescence properties of tungstate phosphors with the double perovskite structure.

关键词： Double perovskite Tungstate phosphor Zn^(2+)-doping Microstructure Luminescence Rare earths

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Effect of Microstructural Characteristics on Fracture Toughness in Direct Energy Deposited Novel Ti-6Al-4V-1Mo Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 119-131页

作者： Chao Xia Kexin zhao xin Zhou Yuqi He Panpan Gao Hengxin Zhang Guangrui Gao Fengying Zhang Hua Tan School of Material Science and Engineering Chang’an UniversityXi’an710064China Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi’an710038China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China Surface Material Protection Co. LtdXi’an710018China

Meeting the damage tolerance requirements for engineering-grade titanium alloys pose a significant challenge in achieving high fracture toughness in direct energy deposition(DED)titanium *** work primarily investigated the relationship betwe.n the microstructure and the fracture toughness of DED new Ti-6Al-4V-1Mo *** types of microstructures we.e designed via two process strategies:high-line energy density(HE)and low-line energy density(LE).Relative to LE samples,HE samples possess larger-sized microstructural characteristics(coarser grain boundaryα(α_(GB)),largerαcolonies,and coarserαlaths).Lessα/βphase boundaries we.e formed by coarserαlaths in the HE samples,increasing the movement of dislocations,resulting in tensile strength decreasing from 1007.1 MPa(LE)to 930.8 MPa(HE)and elongation increasing from 10.8%(LE)to 15.7%(HE).Also,HE samples exhibited an excellent fracture toughness of 114.0 MPa m^(1/2),significantly higher than that of LE samples(76.8 MPa m^(1/2)).An analysis of crack propagation paths was conducted to investigate the factors contributing to *** primary factor enhancing toughness is the frequent obstruction of cracks by coarseαGB and largeαcolonies in HE ***,the pretty large-angle deflections induced by the superposition effect of coarseαGB and largeαcolonies play a vital of significant *** factors induced the long and tortuous high-energy pathways,which resulted in ultimately improved fracture *** discovered microstructural toughening mechanisms can serve as a reference for future studies involving titanium alloys,offering insights on how to enhance fracture toughness by achieving similar characteristics.

关键词： Direct energy deposition Ti-6Al-4V-1Mo Tensile properties Fracture toughness Crack propagation

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Balancing electron transfer and intermediate adsorption ability of metallic Ni-Fe-RE-P bifunctional catalysts via 4f-2p-3d electron interaction for enhanced water splitting

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Journal of Energy Chemistry 2024年第7期94卷 458-465页

作者： Hong-Rui zhao Cheng-Zong Yuan Chenliang Zhou we.kai zhao Lunliang Zhang Cong-Hui Li Lei xin Fuling Wu Shufeng Ye Xiaomeng Zhang Yunfa Chen School of Rare Earths University of Science and Technology of ChinaHefei 230026AnhuiChina Jiangxi Province Research Institute of Rare Earths Ganjiang Innovation AcademyChinese Academy of SciencesGanzhou 341119JiangxiChina State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

Balancing electron transfer and intermediate adsorption ability of bifunctional catalysts via tailoring electronic structures is crucial for green hydrogen production,while it still remains challenging due to lacking efficient ***,one efficient and universal strategy is developed to greatly regulate electronic structures of the metallic Ni-Fe-P catalysts via in-situ introducing the rare earth(RE)atoms(Ni-Fe-RE-P,RE=La,Ce,Pr,and Nd).Accordingly,the as-prepared optimal Ni-Fe-Ce-P/CC self-supported bifunctional electrodes exhibited superior electrocatalytic activity and excellent stability with the low overpotentials of 247 and 331 mV at 100 mA cm^(-2) for HER and OER,*** the assembled electrolyzer,the Ni-Fe-Ce-P/CC as bifunctional electrodes displayed low operation potential of 1.49 V to achieve a current density of 10 mA cm^(-2),and the catalytic performance can be maintained for 100 *** results combined with density functional theory(DFT)calculation reveal that Ce doping leads to electron decentralization and crystal structure distortion,which can tailor the band structures and d-band center of Ni-Fe-P,further increasing conductivity and optimizing intermediate adsorption *** work not only proposes a valuable strategy to regulate the electron transfer and intermediate adsorption of electrocatalysts via RE atoms doping,but also provides a deep under-standing of regulation mechanism of metallic electrocatalysts for enhanced water splitting.

关键词： RE atoms Electron transfer Adsorption energy Oxygen evolution Hydrogen evolution

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