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Journal of Systems Science & Complexity 2024年第3期37卷 1251-1270页

作者： peng Yanjin WANG Lei Nankai University LEBPS and LPMC KLMDASR School of Statistics and Data Science

In this paper, the authors propose a two-stage online debiased lasso estimation and statistical inference method for high-dimensional quantile regression(QR) models in the presence of streaming data. In the first stage, the authors modify the QR score function based on kernel smoothing and obtain the online lasso smoothed QR estimator through iterative algorithms. The estimation process only involves the current data batch and specific historical summary statistics, which perfectly accommodates to the special structure of streaming data. In the second stage, an online debiasing procedure is carried out to eliminate biases caused by the lasso penalty as well as the accumulative approximation error so that the asymptotic normality of the resulting estimator can be established. The authors conduct extensive numerical experiments to evaluate the performance of the proposed method. These experiments demonstrate the effectiveness of the proposed method and support the theoretical results.An application to the Beijing PM2.5 Dataset is also presented.

关键词： Adaptive tuning asymptotic normality debiased lasso online updating quantile regression

Multiple Random Forests Based Intelligent Location of Single-phase Grounding Fault in Power Lines of DFIG-based Wind Farm

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Journal of Modern Power Systems and Clean Energy 2022年第5期10卷 1152-1163页

作者： Yongli Zhu Hua peng School of Electrical and Electronic Engineering North China Electric Power UniversityBaoding 071003China

To address the problems of wind power abandonment and the stoppage of electricity transmission caused by a short circuit in a power line of a doubly-fed induction generator(DFIG) based wind farm, this paper proposes an intelligent location method for a single-phase grounding fault based on a multiple random forests(multi-RF) algorithm. First, the simulation model is built, and the fundamental amplitudes of the zerosequence currents are extracted by a fast Fourier transform(FFT) to construct the feature set. Then, the random forest classification algorithm is applied to establish the fault section locator. The model is resampled on the basis of the bootstrap method to generate multiple sample subsets, which are used to establish multiple classification and regression tree(CART) classifiers. The CART classifiers use the mean decrease in the node impurity as the feature importance,which is used to mine the relationship between features and fault sections. Subsequently, a fault section is identified by voting on the test results for each classifier. Finally, a multi-RF regression fault locator is built to output the predicted fault distance. Experimental results with PSCAD/EMTDC software show that the proposed method can overcome the shortcomings of a single RF and has the advantage of locating a short hybrid overhead/cable line with multiple branches. Compared with support vector machines(SVMs)and previously reported methods, the proposed method can meet the location accuracy and efficiency requirements of a DFIG-based wind farm better.

关键词： Doubly-fed induction generator(DFIG)based wind farm power line multiple random forests(multi-RF) single-phase grounding fault fault location

Modelling and analysis of initial icing roughness with fixed-grid enthalpy method based on DPM-VOF algorithm

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Chinese Journal of Aeronautics 2022年第7期35卷 168-178页

作者： Jie LIU peng KE Department of Civil Helicopter Research and Development China Helicopter Research and Development InstituteTianjin 300000China School of Transportation Science and Engineering Beihang UniversityBeijing 100191China

Ice particles could form under the continuous impingement of incoming supercooled droplets in icing conditions,which will change the surface roughness to enhance the further heat and mass transfer during icing process.A fixed-grid porous enthalpy method based on the improved Discrete Phase Model(DPM)and Volume of Fluid(VOF)integrated algorithm is developed to solve the multiphase heat transfer problem to give more detailed demonstration of the formation of initial ice roughness.The algorithms to determine the criterion of transformation from DPM to VOF and the allocation of source items during transformation are improved to the general DPM-VOF algorithm.Two verification cases,namely two glycerine-solution droplets impact and single droplet freeze,are conducted to verify the accuracy and reliability of the enthalpy-DPMVOF method,where the simulation results match well with experiment phenomena.Ice roughness on a NACA0012 airfoil is precisely captured and the effects on convective heat transfer characteristics are preliminarily revealed.The results illustrate that the enthalpy-DPM-VOF method could successfully capture the characteristics of motion and the phase change process of droplet,as well as balance the calculation accuracy and efficiency.

关键词： Discrete phase model Fixed-grid porous enthalpy method Ice roughness Icing modelling Integrated algorithm Multiphase heat transfer Volume of fluid

Damage detection in beam-like structures using static shear energy redistribution

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Frontiers of Structural and Civil Engineering 2022年第12期16卷 1552-1564页

作者： Xi peng Qiuwei YANG School of Civil and Transportation Engineering Ningbo University of TechnologyNingbo 315211China Engineering Research Center of Industrial Construction in Civil Engineering of Zhejiang Ningbo University of TechnologyNingbo 315211China

In this study,a static shear energy algorithm is presented for the damage assessment of beam-like structures.According to the energy release principle,the strain energy of a damaged element suddenly changes when structural damage occurs.Therefore,the change in the static shear energy is employed to determine the damage locations in beam-like structures.The static shear energy is derived from the spectral factorization of the elementary stiffness matrix and structural deflection variation.The advantage of using shear energy as opposed to total energy is that only a few deflection data points of the beam structure are required during the process of damage identification.Another advantage of the proposed approach is that damage detection can be performed without establishing a structural finiteelement model in advance.The proposed technique is first validated using a numerical example with single,multiple,and adjacent damage scenarios.A channel steel beam and rectangular concrete beam are employed as experimental cases to further verify the proposed approach.The results of the simulation and experiment examples indicate that the proposed algorithm provides a simple and effective method for defect localization in beam-like structures.

关键词： damage detection beam structure strain energy static displacement variation energy damage index

Development and application of bionic systems consisting of tumor-cell membranes

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2022年第9期23卷 770-777页

作者： Tianjiao peng Jun YAO Clinical Medical College Henan University of Science and TechnologyLuoyang471003China Department of Oncology the First Affiliated Hospital of Henan University of Science and TechnologyLuoyang471003China Epigenetics and Molecular Biology Laboratory the First Affiliated Hospital of Henan University of Science and TechnologyLuoyang471003China

Malignant tumors pose a serious threat to human health but during the past decade,great progress has been made in the treatment of tumors.The tumorcell membrane is well constructed and can be used to solve problems in tumor therapy.Tumor-cell membranes exhibit not only high biocompatibility duc to their homology but also enhanced therapeutic ffects when combined with nanotechnology.Meanwhile,nanoma-tcrials show high selectivity,sensitivity,and clinical transformation potential.Enhanced immunotherapy or tumor vaccines have potential clinical application because of tumor-membranc surfacc-specific antigens.Several studies have confirmed the feasibility and ad-vantages of using tumorcell membrane incorporated nanosystems for tumor therapy.Considering all this,we focus in this review on the application of tumor-cell-membrane bionic platforms and,in the summary,provide ideas for new scientific developments.

关键词： membranes tumor clinical

A tRF oligomerizes Nucleolin to stabilize metastasis-favoring transcripts

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Science China(Life Sciences) 2023年第3期66卷 646-648页

作者： Jiawei Guo Yong peng Laboratory of Molecular Oncology Frontiers Science Center for Disease-related Molecular Network State Key Laboratory of Biotherapy and Cancer Center West China Hospital Sichuan University

Apart from bringing amino acids to ribosomes for protein biogenesis,transfer RNA(t RNA)can be cleaved into small non-coding RNAs,named as t RFs or ts RNAs.These small RNA fragments were firstly thought as random degradation products of t RNAs until the induction of certain t RFs were observed in specific stress conditions(Li et al.,2008).

关键词： metastasis bringing

Numerical Analysis on Solidification Behavior of Graphene Nanoplatelet Based Nanofluid in Cold Storage Cavity

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Journal of Thermal Science 2022年第4期31卷 1180-1193页

作者： CHEN Chen FENG Shiyu peng Hao peng Xiaotian LIU Weihua College ofAerospace Engineering Nanjing University ofAeronautics and Astronautics Nanjing 210016China Institute of Thermal Engineering Shanghai Maritime UniversityShanghai 201306China

Addition of graphene nanoplatelet(GNP)into water is a promising method for improving cold storage system performance,and its application requires comprehensive understanding of solidification behavior of GNP-water nanofluid.In the present study,the influences of GNP mass concentration,cold storage cavity size and shape on solid-liquid interface evolution,temperature distribution,streamline profile as well as solidification rate are numerically analyzed.The enthalpy-porosity technique is adopted to track solid-liquid interface.The results show that the enhancement effect of GNPs on solidification is mainly reflected in the final stage in which heat conduction is predominant;the solidification occurs at the bottom of cavity in the early stage,and the solid-liquid interface is similar to the shape of cavity itself and then tends to be circular in the middle and final stages respectively;the reduction degree of solidification time reaches 30.1%at GNP mass concentration of 1.2 wt%under present simulation conditions;decreasing cavity size and adopting triangular cavity are beneficial for promoting the solidification,but they will suppress the enhancement effect of GNPs on solidification.

关键词： cavity shape graphene nanofluid phase change material solidification

Boosting Interfacial Polarization Through Heterointerface Engineering in MXene/Graphene Intercalated-Based Microspheres for Electromagnetic Wave Absorption

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Nano-Micro Letters 2023年第9期15卷 436-460页

作者： Ge Wang Changfeng Li Diana Estevez peng Xu Mengyue peng Huijie Wei Faxiang Qin Institute for Composites Science Innovation(InCSI) School of Materials Science and EngineeringZhejiang University38 Zheda RoadHangzhou 310027People’s Republic of China Ningbo Institute of Technology Zhejiang University1 Qianhu South RdNingbo 315100People’s Republic of China Foshan(Southern China)Institute for New Materials FoshanPeople’s Republic of China

Multi-layer 2D material assemblies provide a great number of interfaces beneficial for electromagnetic wave absorption.However,avoiding agglomeration and achieving layer-by-layer ordered intercalation remain chal-lenging.Here,3D reduced graphene oxide(rGO)/MXene/TiO_(2)/Fe_(2)C lightweight porous microspheres with periodical intercalated structures and pronounced inter-facial effects were constructed by spray-freeze-drying and microwave irradiation based on the Maxwell–Wagner effect.Such approach reinforced interfacial effects via defects introduction,porous skeleton,multi-layer assembly and multi-compo-nent system,leading to synergistic loss mechanisms.The abundant 2D/2D/0D/0D intercalated heterojunctions in the microspheres provide a high density of polari-zation charges while generating abundant polarization sites,resulting in boosted interfacial polarization,which is verified by CST Microwave Studio simulations.By precisely tuning the 2D nanosheets intercalation in the heterostructures,both the polarization loss and impedance matching improve significantly.At a low filler loading of 5 wt%,the polarization loss rate exceeds 70%,and a minimum reflection loss(RLmin)of-67.4 dB can be achieved.Moreover,radar cross-section simulations further confirm the attenuation ability of the optimized porous microspheres.These results not only provide novel insights into understanding and enhancing interfacial effects,but also constitute an attractive platform for implementing heterointerface engineering based on customized 2D hierarchical architectures.

关键词： MXene Hierarchical microspheres Interfacial polarization Spray-freeze-drying Microwave absorption

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体外膜肺氧合在儿童暴发性心肌炎中的应用

中国实用儿科杂志 2022年第3期37卷 195-199页

作者：高倩靳有鹏山东第一医科大学附属省立医院山东大学附属省立医院小儿重症医学科山东济南250021

暴发性心肌炎是一种以急性血流动力学障碍为主要表现的急危重症,起病急、进展快,病死率高。该病目前无特效药物治疗,一般采用对症及支持疗法。近年来,体外膜肺氧合(ECMO)可为暴发性心肌炎患儿提供有效的生命支持,为心脏功能恢复赢得时间... 详细信息

暴发性心肌炎是一种以急性血流动力学障碍为主要表现的急危重症,起病急、进展快,病死率高。该病目前无特效药物治疗,一般采用对症及支持疗法。近年来,体外膜肺氧合(ECMO)可为暴发性心肌炎患儿提供有效的生命支持,为心脏功能恢复赢得时间,提高该病的抢救成功率。该文就目前ECMO在儿童暴发性心肌炎中的应用和进展做一简单综述。

关键词：暴发性心肌炎体外膜肺氧合儿童

Experimental and theoretical study on the break phenomenon of self-pulsation for liquid-centered swirl coaxial injectors

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2022年第2期23卷 140-155页

作者： peng-jin CAO Xiao BAI Qing-lian LI peng CHENG Science and Technology on Scramjet Laboratory College of Aerospace Science and EngineeringNational University of Defense TechnologyChangsha 410073China

Experimental observations together with theoretical analysis were conducted to investigate the break phenomenon and the corresponding mechanisms of self-pulsation for a liquid-centered swirl coaxial injector with recess number of RN=1.Instantaneous spray images were obtained based on background light imaging technology with a high-speed camera.By dynamic analysis of the flow process of the liquid sheet in the recess chamber,a 1D self-pulsation theoretical model was established,and the self-sustaining mechanisms of self-pulsation were analyzed in depth.The results show that the increase of the momentum flux ratio will lead to the occurrence of the break phenomenon of self-pulsation for the injector with a larger recess length,and the frequency and intensity of self-pulsation before and after the break phenomenon differ significantly.The flow dynamics in the recess chamber sequentially transform from a periodic expansion-dominated flow to a stable flow,and then develop to a periodic contraction-dominated flow during the break process of self-pulsation.With the occurrence of self-pulsation before the break phenomenon,the liquid sheet has little effect on the pressure disturbance in the recess chamber.In contrast,with the occurrence of self-pulsation after the break phenomenon,the pressure disturbance is obviously affected by the liquid sheet.Based on the theoretical analysis model of self-pulsation,the self-pulsation frequency can be predicted.Furthermore,the self-sustaining mechanism of self-pulsation before and after the break phenomenon is preliminarily confirmed.The energy transfer between the gas-and liquid-phase is an important factor for maintaining the self-pulsation process.

关键词： Break phenomenon Theoretical model of self-pulsation Pressure oscillation characteristics Recess Liquid-centered swirl coaxial(LCSC)injector