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Error modeling and compensating of a novel 6-DOF aeroengine rotor docking equipment

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Chinese Journal of Aeronautics 2022年第6期35卷 312-324页

作者： Tianyi ZHOU Hang GAO Xuanping WANG Lun LI Qing LIU key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of TechnologyDalian 116024China AECC Shenyang Liming Aero-engine Co. LtdChina

In the docking process of aeroengine rotor parts,docking accuracy that indicates the gaps between the end faces is strictly required.A key issue is improving docking accuracy using automated docking equipment.In this paper,a systematic study is carried out on the error modeling and compensation of a novel six-degrees-of-freedom(6-DOF)docking equipment for aeroengine rotors.First,a new model for indicating the main indexes of docking accuracy is proposed.Then,the error model of a specially designed 6-DOF docking equipment is established based on a modified Denavit Hartenberg method with five parameters.Subsequently,two error compensation methods are proposed.Based on the above models,a docking accuracy simulation algorithm is proposed using the Monte Carlo method.Finally,verification experiments are conducted.The results show that,for the maximum values and standard deviations of the gaps between the rotor end-faces in the actual and target positions and attitudes,i.e.,main indexes that represent docking accuracy,the deviation rates between the simulation and experimental results are less than20%.The modeling methods have referential significance.The decline rates of these values are 50–65%when using the two proposed compensation methods.The compensation methods significantly improve the docking accuracy.

关键词： Accuracy analysis Aeroengine rotor Docking Error compensation Error models Multi-degree-of-freedom structures

Elliptical vibration cutting of large-size thin-walled curved surface parts of pure iron by using diamond tool with active cutting edge shift

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Chinese Journal of Aeronautics 2023年第6期36卷 402-419页

作者： Zhenhua JIAO Renke KANG Dongxing DU Jiang GUO key laboratory for precision and non-traditional machining of ministry of education Dalian University of TechnologyDalian 116024China Institute of Mechanical Manufacturing technology China Academy of Engineering PhysicsMianyang 621999China

Large-size thin-walled curved surface parts of pure iron are crucial in aerospace,national defense,energy and precision physical experiments.However,the high machining accuracy and surface quality are difficult to achieve due to the serious tool wear and deformation when machining the parts with conventional cutting tools.In this paper,an elliptical vibration cutting(EVC)with active cutting edge shift(ACES)based on a long arbor vibration device is proposed for ultraprecision machining the pure iron parts by using diamond tool.Compared with cutting at a fixed cutting edge,the influence of ACES on the EVC was analyzed.Experiments in EVC of pure iron with ACES were conducted.The evolutions of the surface roughness,surface topography,and chip morphology with tool wear in EVC with ACES are revealed.The reasonable parameters of ultraprecision machining the pure iron parts by EVC with ACES were determined.It shows that the ACES has a slight influence on the machined surface roughness and surface topography.The diamond tool life can be significantly prolonged in EVC of pure iron with ACES than that with a fixed cutting edge,so that high profile accuracy and surface quality could be obtained even at higher nominal cutting speed.A typical thin-walled curved surface pure iron part with diameter φ240 mm,height 122 mm,and wall thickness 2 mm was fabricated by the presented method,and its profile error and surface roughness achieved PV 2.2μm and Ra less than 50 nm,respectively.

关键词： Curved surface Diamond tool Elliptical vibration cutting Pure iron Thin-walled parts

Moisture electricity generation:Mechanisms,structures,and applications

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Nano Research 2023年第5期16卷 7496-7510页

作者： Quanmao Wei Wenna Ge Zichao Yuan Shixu Wang Chenguang Lu Shile Feng Lei Zhao Yahua Liu key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of TechnologyDalian 116024China key laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development CenterMianyang 621000China

With the increasing concern of energy crisis and global warming,the whole globe is in an urgent need to develop clean energy that comes from renewable sources and does not harm the environment to fulfill the carbon neutralization and green earth commitments.Water is the most abundant substance on earth and has been historically used as the major energy carriers in watermill,water wheel,hydroelectricity.Moisture electricity generation is another emerging technology that can convert lowgrade energy in the widely-accessible moisture to electricity simply by the integration of moisture,electrodes,deliberatelydesigned hygroscopic films.Recent research on moisture electricity generators(MEGs)led to the creation of a series of selfpowered sensors and in some occasions they have replaced conventional batteries to power miniaturized devices.In this review,the basic mechanisms of MEGs are firstly clarified,three categories of them,i.e.,gradient structure,homogeneous structure,and heterogeneous structure depending on the structure of hygroscopic films,are then introduced.Furthermore,recent advances in the fabrication,characteristics,performance of MEGs are summarized,MEGs with continuous or transient output that could be applied in self-powered sensors and power sources are discussed.Finally,some remaining challenges and our perspectives on MEGs are highlighted.

关键词： moisture hygroelectricity nanogenerators structures hygroscopic film

Effects of Surface Roughness on Interface Bonding Performance for 316H Stainless Steel in Hot-Compression Bonding

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Acta Metallurgica Sinica(English Letters) 2023年第5期36卷 771-788页

作者： Yong Zhao Bi-Jun Xie Jin-Long Zhang Qin-Qiang Wang Bin Xu Jiang Guo Zhu-Ji Jin Ren-Ke Kang Dian-Zhong Li key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of TechnologyDalian116024China Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The metallurgical bonding quality of bonding joints is affected by the substrate surface state in hot-compression bonding(HCB),and the surface roughness is a core indicator of the surface state.However,the effects of surface roughness on interface bonding performance(IBP)in the HCB process are unclear for substrates with refractory oxide scales.This study presents the effects of surface roughness on IBP for 316H stainless steel joints fabricated by HCB.A set of HCB parameters for interface bonding critical state of 316H stainless steel joints was determined.The HCB experiments were carried out under parameters of interface bonding critical state to amplify the effect of surface roughness.The interface morphologies,element distribution,and tensile properties were used to characterize the IBP.As a result,the formation mechanisms of the interface pits were revealed and the variation trend of pit number with the roughness was summarized.Finally,the mapping relation between surface roughness and IBP was established.The results show that the degree of rotational dynamic recrystallization becomes weaker with the decrease in the surface roughness and the interface bonding mechanism is completely transformed into discontinuous dynamic recrystallization when the roughness is lower than 0.020μm Sa.The number of interfacial pits decreases as the roughness decreases owing to the weakening of oxide scale aggregation and abrasive inclusion mechanism.The elongation of the tensile specimen cannot increase significantly while the roughness is lower than 0.698μm Sa.

关键词： Surface roughness Interface bonding performance Hot-compression bonding Mapping relation Critical state

Machine learning solution for regional landslide susceptibility based on fault zone division strategy

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Journal of Mountain Science 2024年第5期21卷 1745-1760页

作者： WANG Yunhao WANG Luqi LIU Songlin SUN Weixin LIU Pengfei ZHU Lin YANG Wenyu GUO Tong School of Civil Engineering Chongqing UniversityChongqing 400045China key laboratory of New technology for Construction of Cities in Mountain Area Chongqing UniversityMinistry of EducationChongqing 400045China National Joint Engineering Research Center of Geohazards Prevention in the Reservoir Areas Chongqing UniversityChongqing 400045China Institute of Geological Environment Monitoring Chongqing 401147China Chongqing 205 Geological Team Chongqing 401121China

Landslide susceptibility assessment is an essential tool for disaster prevention and management. In areas with multiple fault zones, the impact of fault zone on slope stability cannot be disregarded. This study performed qualitative analysis of fault zones and proposed a zoning method to assess the landslide susceptibility in Chengkou County, Chongqing Municipality, China. The region within a distance of 1 km from the faults was designated as sub-zone A, while the remaining area was labeled as sub-zone B. To accomplish the assessment, a dataset comprising 388 historical landslides and 388 non-landslide points was used to train the random forest model. 10-fold cross-validation was utilized to select the training and testing datasets for the model. The results of the models were analyzed and discussed, with a focus on model performance and prediction uncertainty. By implementing the proposed division strategy based on fault zone, the accuracy, precision, recall, F-score, and AUC of both two sub-zones surpassed those of the whole region. In comparison to the results obtained for the whole region, sub-zone B exhibited an increase in AUC by 6.15%, while sub-zone A demonstrated a corresponding increase of 1.66%. Moreover, the results of 100 random realizations indicated that the division strategy has little effect on the prediction uncertainty. This study introduces a novel approach to enhance the prediction accuracy of the landslide susceptibility mapping model in areas with multiple fault zones.

关键词： Landslide susceptibility mapping Fault division strategy Random forest GIS

Comparison of surface integrity for dry and wet drilling of 49Fe-49Co-2V alloy

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Chinese Journal of Aeronautics 2022年第6期35卷 325-338页

作者： Yuan ZHANG Zhigang DONG Yan BAO Renke KANG Xin HUANG Dongming GUO key laboratory for precision and non-traditional machining technology of the ministry of education School of Mechanical EngineeringDalian University of TechnologyDalian 116024China AVIC Xi’an Flight Automatic Control Research Institute Xi’an 710076China

Working performances of the components made out of 49Fe-49Co-2V alloy are closely related to the surface integrity of the drilled holes,which are influenced remarkably by the cooling conditions.The present study focuses on the surface integrity differences between wet and dry drilled 49Fe-49Co-2V alloy holes.The drilled hole surface roughness and topographies,metallurgical and mechanical properties,and the exit characterizations were obtained using optical microscopy(OM),scanning electron microscopy(SEM),electron backscatter diffraction microscopy(EBSD),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS)and Vickers hardness techniques,etc.The effects of cooling conditions on the surface integrity were concluded and the influence mechanisms were analyzed based on the force and temperature differences in drilling process with different cooling conditions.It is found that the surface roughness and the thickness of refined-grain region of the dry drilled holes are larger than those of wet drilled holes;work hardening induced by wet drilling is more serious than dry drilling;chippings occurred in the exits of the wet drilled holes due to the material brittleness,which could be avoided by dry drilling.The surface integrity differences of wet and dry drilled holes are closely related to the force and temperature differences in drilling process with different cooling conditions.

关键词： 49Fe-49Co-2V alloy Cooling condition Drilling Exit chipping Microstructure Surface integrity Surface quality Work hardening

A New Dynamics Analysis Model for Five-Axis machining of Curved Surface Based on Dimension Reduction and Mapping

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Chinese Journal of Mechanical Engineering 2023年第6期36卷 172-184页

作者： Minglong Guo Zhaocheng Wei Minjie Wang Zhiwei Zhao Shengxian Liu key laboratory for precision and non-traditional machining technology of ministry of education Dalian University of TechnologyDalian 116024People’s Republic of China Institute of Mechanical Manufacturing technology China Academy of Engineering PhysicsMianyang 621000China

The equipment used in various fields contains an increasing number of parts with curved surfaces of increasing size.Five-axis computer numerical control(CNC)milling is the main parts machining method,while dynamics analysis has always been a research hotspot.The cutting conditions determined by the cutter axis,tool path,and workpiece geometry are complex and changeable,which has made dynamics research a major challenge.For this reason,this paper introduces the innovative idea of applying dimension reduction and mapping to the five-axis machining of curved surfaces,and proposes an efficient dynamics analysis model.To simplify the research object,the cutter position points along the tool path were discretized into inclined plane five-axis machining.The cutter dip angle and feed deflection angle were used to define the spatial position relationship in five-axis machining.These were then taken as the new base variables to construct an abstract two-dimensional space and establish the mapping relationship between the cutter position point and space point sets to further simplify the dimensions of the research object.Based on the in-cut cutting edge solved by the space limitation method,the dynamics of the inclined plane five-axis machining unit were studied,and the results were uniformly stored in the abstract space to produce a database.Finally,the prediction of the milling force and vibration state along the tool path became a data extraction process that significantly improved efficiency.Two experiments were also conducted which proved the accuracy and efficiency of the proposed dynamics analysis model.This study has great potential for the online synchronization of intelligent machining of large surfaces.

关键词： Curved surface Five-axis machining Dimension reduction and mapping Milling force Dynamics

Aging hallmarks of the primate ovary revealed by spatiotemporal transcriptomics

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Protein & Cell 2024年第5期15卷 364-384页

作者： Huifen Lu Ying Jing Chen Zhang Shuai Ma Weiqi Zhang Daoyuan Huang Bin Zhang Yuesheng Zuo Yingying Qin Guang-Hui Liu Yang Yu Jing Qu Si Wang Advanced Innovation Center for Human Brain Protection National Clinical Research Center for Geriatric DisordersXuanwu Hospital Capital Medical UniversityBeijing 100053China State key laboratory of Stem Cell and Reproductive Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China Aging Translational Medicine Center International Center for Aging and CancerBeijing Municipal Geriatric Medical Research CenterXuanwu HospitalCapital Medical UniversityBeijing 100053China State key laboratory of Membrane Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China CAS key laboratory of Genomic and precision Medicine Beijing Institute of GenomicsChinese Academy of SciencesBeijing 100101China Institute for Stem cell and Regeneration CASBeijing 100101China China National Center for Bioinformation Beijing 100101China The Fifth People’s Hospital of Chongqing Chongqing 400062China Sino-Danish College University of Chinese Academy of SciencesBeijing 101408China Sino-Danish Center for education and Research Beijing 101408China Department of Obstetrics and Gynecology Center for Reproductive MedicinePeking UniversityThird HospitalBeijing 100191China Clinical Stem Cell Research Center Peking UniversityThird HospitalBeijing 100191China Center for Reproductive Medicine Cheeloo College of MedicineShandong UniversityJinan 250012China key laboratory of Reproductive Endocrinology of ministry of education National Research Center for Assisted Reproductive Technology and Reproductive GeneticsShandong Key Laboratory of Reproductive MedicineShandong Provincial Clinical Research Center for Reproductive HealthJinan 250012China key laboratory of Organ Regeneration and Reconstruction Institute of ZoologyChinese Academy of SciencesBeijing 100101China Aging Biomarker Consortium Beijing 100101China

The ovary is indispensable for female reproduction,and its age-dependent functional decline is the primary cause of infertility.However,the molecular basis of ovarian aging in higher vertebrates remains poorly understood.Herein,we apply spatiotemporal transcriptomics to benchmark architecture organization as well as cellular and molecular determinants in young primate ovaries and compare these to aged primate ovaries.From a global view,somatic cells within the non-follicle region undergo more pronounced transcriptional fluctuation relative to those in the follicle region,likely constituting a hostile microenvironment that facilitates ovarian aging.Further,we uncovered that inflammation,the senescent-associated secretory phenotype,senescence,and fibrosis are the likely primary contributors to ovarian aging(PCOA).Of note,we identified spatial co-localization between a PCOA-featured spot and an unappreciated MT2(Metallothionein 2)highly expressing spot(MT2^(high))characterized by high levels of inflammation,potentially serving as an aging hotspot in the primate ovary.Moreover,with advanced age,a subpopulation of MT2^(high)accumulates,likely disseminating and amplifying the senescent signal outward.Our study establishes the first primate spatiotemporal transcriptomic atlas,advancing our understanding of mechanistic determinants underpinning primate ovarian aging and unraveling potential biomarkers and therapeutic targets for aging and age-associated human ovarian disorders.

关键词： spatial transcriptome primate ovary aging senescence inflammation

Novel gripper module and method for automated assembly of miniature parts

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Advances in Manufacturing 2023年第2期11卷 295-310页

作者： Zhi-Yong Zhang Xiao-Dong Wang Tong-Qun Ren Tian-Lun Jin key laboratory for Micro/Nano technology and System of Liaoning Province Dalian University of TechnologyDalian116024LiaoningPeople's Republic of China key laboratory for precision and non-traditional machining of ministry of education Dalian University of TechnologyDalian116024LiaoningPeople's Republic of China

During assembly process,the miniature part needs to be fixed in its assembly position.In some occasions where adhesive is used,the joining force is not established due to the adhesive curing process,in that case the locking of parts is required.Manual locking is difficult to meet the increasing demand for mass production.To solve this problem and realize fully automatic assembly,a novel gripper module was designed and corresponding locking method was proposed.Thanks to the functional integration,the gripper module is capable of manipulating and locking the part.This module is integrated into the assembly system and plays a crucial role in automatic assembly.The locking method for automatic assembly is based on the integration of the part picking up and the locking unit releasing.After being placed accurately at its desired position,the miniature part can be automatically locked by releasing the locking unit.The innovative structure and mechanism of the gripper module convert the spring force into the locking force of the miniature part,ensuring non-rigid locking and suitable small locking force.Locking principle,flexibility and limitations of the proposed method were clarified in detail.Moreover,an effective compensation strategy was used to achieve accurate and stable pickup of the part,which increased the reliability of the assembly process.During automatic locking,the disturbances to the part due to the eccentric load were analyzed.The effectiveness of the gripper module and proposed method was verified by experiment.Experimental results indicated that the modular system integrated with the gripper module could meet the requirements of fully automatic assembly.Manual locking is replaced by automatic locking,and workers are liberated from tedious manual operations.The improvement of automation level enables assembly equipment to be applied to mass production scenarios.

关键词： Fully automatic assembly Miniature parts Automatic locking Gripper module