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Model-driven path planning for robotic plasma cutting of branch pipe with single Y-groove based on pipe-rotating scheme

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Advances in Manufacturing 2024年第1期12卷 94-107页

作者： Yan Liu Qiu Tang Xin-cheng tian School of Control Science and Engineering Shandong UniversityJinan250061People’s Republic of China Engineering Research Center of Intelligent Unmanned System Ministry of EducationJinan250061People’s Republic of China School of Mechanical and Electronic Engineering Shandong Jianzhu UniversityJinan250101People’s Republic of China

The automatic cutting of intersecting pipes is a challenging task in *** improved automation and accuracy,this paper proposes a model-driven path planning approach for the robotic plasma cutting of a branch pipe with a single ***,it summarizes the intersection forms and introduces a dual-pipe intersection *** on this model,the moving three-plane structure(a description unit of the geometric characteristics of the intersecting curve)is constructed,and a geometric model of the branch pipe with a single Y-groove is ***,a novel mathematical model for plasma radius and taper compensation is ***,the compensation model and groove model are integrated by establishing movable ***,to prevent collisions between the plasma torch and workpiece,the torch height is planned and a branch pipe-rotating scheme is *** the established models and moving frames,the planned path description of cutting robot is provided in this novel *** accuracy of the proposed method is verified by simulations and robotic cutting experiments.

关键词： Automatic groove cutting of intersecting pipes Model-driven robot path planning Plasma beam radius and taper compensation

Measurement of gear tooth dynamic deformation using dynamic speckle photography

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Chinese Science Bulletin 1998年第6期43卷 514-518页

作者： Jianfeng Li xing Ai Zhiren tian Shandong Univ Technol Jinan 250061 Peoples R China

A new method of measuring gear tooth dynamic deformation is proposed. Dynamic speckle photographs of the rotating gear tooth have been achieved by combining the pulsed ruby laser with the out-syn-signal. Double speckle patterns of the whole mesh period of gear tooth are obtained by accurate time delay of the ruby laser. Gear tooth dynamic deformation of the whole mesh period is achieved using the automatic image processing. Testing results show that the trends of gear tooth deformation coincides with the calculation by the finite element method. The success of this new trying provides a new technique for the measurement of gear tooth dynamic deformation.

关键词： pulsed ruby laser dynamic speckle photography image process gears deformation.

MeCP2:multifaceted roles in gene regulation and neural development

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Neuroscience Bulletin 2014年第4期30卷 601-609页

作者： tian-Lin cheng Zilong Qiu Institute of Neuroscience Shanghai Institutes for Biological SciencesChinese Academy of Sciences

Methyl-CpG-binding protein 2 （MeCP2） is a classic methylated-DNA-binding protein, dysfunctions of which lead to various neurodevelopmental disorders such as Rett syndrome and autism spectrum disorder. Initially recognized as a transcriptional repressor, MeCP2 has been studied extensively and its functions have been expanded dramatically in the past two decades. Recently, it was found to be involved in gene regulation at the post-transcriptional level. MeCP2 represses nuclear microRNA processing by interacting directly with the Drosha/DGCR8 complex. In addition to its multifaceted functions, MeCP2 is remarkably modulated by post- translational modifications such as phosphorylation, SUMOylation, and acetylation, providing more regulatory dimensions to its functions. The role of MeCP2 in the central nervous system has been studied extensively, from neurons to glia. Future investigations combining molecular, cellular, and physiological methods are necessary for defining the roles of MeCP2 in the brain and developing efficient treatments for MeCP2-related brain disorders.

关键词： MeCP2 Rett syndrome central nervous system gene expression regulation post-translationalmodification post-transcriptional regulation glia

Multi-perspective analysis on rainfall-induced spatial response of soil suction in a vegetated soil

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1280-1291页

作者： Zhiliang cheng Wanhuan Zhou Chen tian State Key Laboratory of Internet of Things for Smart City Department of Civil and Environmental EngineeringUniversity of MacaoMacaoChina

In this study, an intelligent monitoring platform is established for continuous quantification of soil,vegetation, and atmosphere parameters (e.g. soil suction, rainfall, tree canopy, air temperature, and windspeed) to provide an efficient dataset for modeling suction response through machine learning. Twocharacteristic parameters representing suction response during wetting processes, i.e. response time andmean reduction rate of suction, are formulated through multi-gene genetic programming (MGGP) usingeight selected influential parameters including depth, initial soil suction, vegetation- and atmosphererelated parameters. An error standardebased performance evaluation indicated that MGGP has appreciable potential for model development when working with even fewer than 100 data. Global sensitivityanalysis revealed the importance of tree canopy and mean wind speed to estimation of response timeand indicated that initial soil suction and rainfall amount have an important effect on the estimatedsuction reduction rate during a wetting process. Uncertainty assessment indicated that the two MGGPmodels describing suction response after rainfall are reliable and robust under uncertain conditions. Indepth analysis of spatial variations in suction response validated the robustness of two obtained MGGPmodels in prediction of suction variation characteristics under natural conditions.

关键词： Global sensitivity analysis(GSA) Multi-gene genetic programming(MGGP) Soil suction response Spatial variation of suction response Uncertainty assessment

Testing Regression Coefficients in High-Dimensional and Sparse Settings

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Acta Mathematica Sinica,English Series 2021年第10期37卷 1513-1532页

作者： Kai XU Yan tian Qing cheng School of Mathematics and Statistics Anhui Normal UniversityWuhu 241002P.R.China Center for Quantitative Medicine Duke-NUS Medical SchoolNational University of SingaporeSingapore 169856

In the high-dimensional setting,this article considers a canonical testing problem in multivariate analysis,namely testing coefficients in linear regression *** tests for highdimensional regression coefficients have been proposed in the recent ***,these tests are based on the sum of squares type statistics,that perform well under the dense alternatives and suffer from low power under the sparse *** order to attack this issue,we introduce a new test statistic which is based on the maximum type statistic and magnifies the sparse *** limiting null distribution of the test statistic is shown to be the extreme value distribution of type I and the power of the test is *** particular,it is shown theoretically and numerically that the test is powerful against sparse *** studies are carried out to examine the numerical performance of the test and to compare it with other tests available in the literature.

关键词： Extreme value distribution high-dimensional linear models maximum-type-test

Base-Promoted Synthesis of 3-Alkenyl-2-pyridones from N-Propargyl-β-enaminones and Aryl Aldehydes

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Chinese Journal of Chemistry 2021年第10期39卷 2781-2788页

作者： Qingyu tian Shangyun Xiao Guolin cheng Xiamen Key Laboratory of Optoelectronic Materials and Advanced Manufacturing College of Materials Science and EngineeringInstrumental Analysis CenterHuaqiao UniversityXiamenFujian361021 China

Main observation and conclusion In this article,we report a base-promoted sequential cyclization/aldol-type condensation/isomerization cascade reaction of N-propargyl-β-enaminones with aryl *** key step in this protocol is the generation of 1,4-oxazepine anions from N-propargyl-β-enaminones under basic conditions,which are captured by aryl *** method allows the formation of one pyridone core and one C—C double bond in“one pot”,and the preparation of a variety of densely decorated pyridone derivatives in moderate to good yields with broad functional group tolerance.

关键词： Domino reactions Aldehydes Alkenes Enaminone Pyridones

PDCD2 as a prognostic biomarker in glioma correlates with malignant phenotype

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Genes & Diseases 2024年第5期11卷 390-406页

作者： Fengsheng Dai Yixiao Yuan Jiaqi Hao xing cheng Xiangyi Zhou Li Zhou Rui tian Yi Zhao Tingxiu Xiang Department of Oncology The First Affiliated Hospital of Chongqing Medical UniversityChongqing 400010China Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment Chongqing University Cancer HospitalChongqing 400030China Department of Neurosurgery Xiangya HospitalCentral South UniversityChangshaHunan 410008China Hunan International Scientific and Technological Cooperation Base of Brain Tumor Research Xiangya HospitalCentral South UniversityChangshaHunan 410008China Department of Neuro-Oncology Chongqing University Cancer HospitalChongqing 400030China

Programmed cell death 2(PDCD2)is related to cancer progression and chemotherapy *** role of PDCD2 in solid cancers(excluding hematopoietic malignancies)and their diagnosis and prognosis remains *** TCGA,CGGA,GEPIA,cBioPortal,and GTEx databases were analyzed for expression,prognostic value,and genetic modifications of PDCD2 in cancer *** enrichment analysis,CCK8,colony formation assay,transwell assay,and xenograft tumor model were undertaken to study the PDCD2’s biological function in glioma(GBMLGG).The PDCD2 gene was associated with solid cancer *** the functional enrichment analysis results,PDCD2 was shown to participate in several important GBMLGG biological *** cells may be inhibited in their proliferation,migration,invasion,and xenograft tumor growth by knocking down *** research can provide new insights into solid cancer prognostic biomarkers of PDCD2.

关键词： Biomarker Glioma Programmed cell death 2 Progression Solid cancer

Comparison of Heat Transfer in Gravity-Driven Granular Flow near Different Surfaces

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Journal of Thermal Science 2021年第2期30卷 441-450页

作者： GUO Zhigang tian xing YANG Jian SHI Tuo WANG Qiuwang MOE Key Laboratory of Thermo-Fluid Science and Engineering Xi'an Jiaotong UniversityXi'an 710049China

Heat transfer in gravity-driven granular flow has been encountered in many industrial processes,such as waste heat recovery and concentrated solar *** understand more about Moving Bed Heat Exchanger (MBHE) applied in this field,numerical simulation was carried out for the characteristics of granular flow near different surfaces through discrete element method (DEM).In this paper,both the performances of particles motion and heat transfer were ***'s found that,even though the macroscopic granular flow is similar to fluid,there is still obvious discrete nature *** fluctuations of parameters in granular flow are inevitable which is more obvious in the circular tube cases.A special phenomenon,where competition motion is found,is resulted from discrete nature of *** terms of heat transfer,overall heat transfer coefficients for plate are higher than that of tube owing to better contact between particles and ***,due to competition motion,particles in high temperature tend to contact the tube,which is beneficial to heat transfer in some local *** heat transfer characteristics above will also affect the temperature distribution near the outlet of different geometries.

关键词： gravity-driven granular flow discrete element method(DEM) heat transfer numerical simulation

Adaptive allocation strategy for cooperatively jamming netted radar system based on improved cuckoo search algorithm

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Defence Technology（防务技术） 2023年第6期24卷 285-297页

作者： De-jiang Lu xing Wang Xiao-tian Wu You Chen Aviation Engineering School Air Force Engineering UniversityXi'an710038China

The jamming resource allocation problem of the aircraft formation cooperatively jamming netted radar system is *** adaptive allocation strategy based on dynamic adaptive discrete cuckoo search algorithm(DADCS)is proposed,whose core is to adjust allocation scheme of limited jamming resource of aircraft formation in real time to maintain the best jamming effectiveness against netted radar ***,considering the information fusion rules and different working modes of the netted radar system,a two-factor jamming effectiveness evaluation function is constructed,detection probability and aiming probability are adopted to characterize jamming effectiveness against netted radar system in searching and tracking mode,*** a nonconvex optimization model for cooperatively jamming netted radar system is ***,a dynamic adaptive discrete cuckoo search algorithm(DADCS)is constructed by improving path update strategies and introducing a global learning mechanism,and a three-step solution method is proposed *** results are provided to demonstrate the advantages of the proposed optimization strategy and the effectiveness of the improved algorithm.

关键词： Cuckoo search algorithm Netted radar system Radar countermeasures Resource allocation Information fusion