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Acta Mathematica Sinica,English Series 2024年第4期40卷 985-999页

作者： yi DENG Qiang x.ONG shu Wei LI School of Economics and Statistics Guangzhou UniversityGuangzhou 510006P.R.China

Recurrent event data are commonly encountered in many scientific fields,including biomedical studies,clinical trials and epidemiological surveys,and many statistical methods have been proposed for their *** this paper,we consider to use a weighted composite endpoint of recurrent and terminal events,which is weighted by the severity of each event,to assess the overall effects of covariates on the two types of events.A flex.ble additive-multiplicative model incorporating both multiplicative and additive effects on the rate function is proposed to analyze such weighted composite event process,and more importantly,the dependence structure among the recurrent and terminal events is left *** the estimation,we construct the unbiased estimating equations by virtue of the inverse probability weighting technique,and the resulting estimators are shown to be consistent and asymptotically normal under some mild regularity *** evaluate the finite-sample performance of the proposed method via simulation studies and apply the proposed method to a set of real data arising from a bladder cancer study.

关键词： Additive-multiplicative rates model estimating equation recurrent events terminal event weighted composite endpoint

Vanadium(V) Complex.s Containing Unsymmetrical N-Heterocyclic Carbene Ligands: Highly Efficient Synthesis and Catalytic Behavior towards Ethylene/Propylene Copolymerization

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Chinese Journal of Polymer Science 2024年第1期42卷 32-41,I0006页

作者： yi-Cong Wang Hui Zhat Pei-yi Cheng shu Zhang x.ang-Wei Liu yi-x.an Wu State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBejing 100029China

The highly efficient method has been developed for the synthesis of NHC·VOCl_(3) containing symmetrical or unsymmetrical Nheterocyclic carbene(NHC) ligands by the transmetallation reaction of NHC·AgCl with VOCl_(3).The total isolated yield of VOCl_(3)[1,3-(2,4,6-Me_(3)C_(6)H_(2))_(2)(NCH=)_(2)C:](V4') reached 86% by transmetallation reaction,which is much higher than that(48%) by direct coordination *** methodology has also been used to synthesize the novel vanadium complex.s containing unsymmetrical NHC ligands of VOCl_(3)[PhCH_(2)NCH=CHNR)C:](V5',R=2,4,6-Me_(3)C_(6)H_(2);V6',R=2,4-Me_(2)-6-Ph-C_(6)H_(2);V7',R=2,6-^(i)Pr_(2)-C_(6)H_(3)) with high yield,which could not be obtained by direct coordination *** catalytic activity and copolymerization ability would be improved by introducing unsymmetrical NHC ligands due to their less steric bulky *** vanadium complex.V5' containing unsymmetrical NHC ligand ex.ibits higher catalytic activity(3.7×10^(5)g_(copolymer)·mol^(-1) of V·h^(-1)) than that of V4' containing symmetrical NHC ***,the higher propylene incorporation ratio(45.6 mol%) in the copolymers of ethylene with propylene could be obtained by using V5' than that(39.9%) by using V4'.The results would provide a highly efficient strategy for the synthesis of early transition metal complex.s containing versitile NHC ligands,affording the catalyst with both high catalytic activity and copolymerization ability for the synthesis of high performance polyolefin elastomers.

关键词： Vanadium complex N-heterocyclic carbene ligand Transmetallation reaction Copolymerization of ethylene with propylene

Simulation Study on Constraining Gravitational Wave Propagation Speed by Gravitational Wave and Gamma-ray Burst Joint Observation on Binary Neutron Star Mergers

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Research in Astronomy and Astrophysics 2024年第8期24卷 42-51页

作者： Jin-Hui Rao shu-x. yi Lian Tao Qing-Wen Tang Department of Physics School of Physics and Materials ScienceNanchang UniversityNanchang 330031China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Theories of modified gravity suggest that the propagation speed of gravitational waves(GW)v_gmay deviate from the speed of light c.A constraint can be placed on the difference between c and v_gwith a simple method that uses the arrival time delay between GW and electromagnetic wave simultaneously emitted from a burst *** simulated the joint observation of GW and short gamma-ray burst signals from binary neutron star merger events in different observation campaigns,involving advanced LIGO(aLIGO)in design sensitivity and Einstein Telescope(ET)joint-detected with Fermi/*** a result,the relative precision of constraint on v_gcan reach~10~(-17)(aLIGO)and~10^(-18)(ET),which are one and two orders of magnitude better than that from GW170817,*** continue to obtain the bound of graviton mass m_g≤7.1(3.2)×10~(-20)eV with aLIGO(ET).Applying the Standard-Model Ex.ension test framework,the constraint on v_gallows us to study the Lorentz violation in the nondispersive,nonbirefringent limit of the gravitational *** obtain the constraints of the dimensionless isotropic coefficients S_(00)^(4)at mass dimension d=4,which are-1×10^(-15)

关键词： gravitational waves-(stars)gamma-ray burst general-stars neutron

Effect of multiple coulomb scattering on the beam tests of silicon pix.l detectors

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Nuclear Science and Techniques 2024年第4期35卷 200-207页

作者： Lan-Kun Li Ming-yi Dong Ze Gao Liang-Cheng-Long Jin shu-Jun Zhao School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Particle Detection and Electronics(Institute of High Energy Physics CAS)Beijing 100049China University of Chinese Academy of Science Beijing 100049China University of South China Hengyang 421001China

In the research and development of new silicon pix.l detectors,a collimated monoenergetic charged-particle test beam equipped with a high-resolution pix.l-beam telescope is crucial for prototype verification and performance *** the beam energy is low,the effect of multiple Coulomb scattering on the measured resolution of the Device Under Test(DUT)must be considered to accurately evaluate the performance of the pix.l chips and *** study aimed to investigate the effect of multiple Coulomb scattering on the measured resolution,particularly at low beam *** were conducted using Allpix.(2) to study the effects of multiple Coulomb scattering under different beam energies,material budgets,and telescope *** simulations also provided the minimum energy at which the effect of multiple Coulomb scattering could be *** with the results of a five-layer detector system tested with an electron beam at DESY,the simulation results were consistent with the beam test results,confirming the reliability of the simulations.

关键词： Silicon Pix.l Detectors Beam Telescope Multiple Coulomb Scattering Spatial Resolution

Coupling Analysis of Multiple Machine Learning Models for Human Activity Recognition

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Computers, Materials & Continua 2024年第6期79卷 3783-3803页

作者： yi-Chun Lai shu-yin Chiang Yao-Chiang Kan Hsueh-Chun Lin Department of Public Health China Medical UniversityTaichung406040Taiwan Department of Information and Telecommunications Engineering Ming Chuan UniversityGui-ShanTaoyuan333Taiwan Department of Electrical Engineering Yuan Ze UniversityChung-Li32003Taiwan Department and Institute of Health Service Administrations China Medical UniversityTaichung406040Taiwan

Artificial intelligence(AI)technology has become integral in the realm of medicine and healthcare,particularly in human activity recognition(HAR)applications such as fitness and rehabilitation *** study introduces a robust coupling analysis framework that integrates four AI-enabled models,combining both machine learning(ML)and deep learning(DL)approaches to evaluate their effectiveness in *** analytical dataset comprises 561 features sourced from the UCI-HAR database,forming the foundation for training the ***,the MHEALTH database is employed to replicate the modeling process for comparative purposes,while inclusion of the WISDM database,renowned for its challenging features,supports the framework’s resilience and *** ML-based models employ the methodologies including adaptive neuro-fuzzy inference system(ANFIS),support vector machine(SVM),and random forest(RF),for data *** contrast,a DL-based model utilizes one-dimensional convolution neural network(1dCNN)to automate feature ***,the recursive feature elimination(RFE)algorithm,which drives an ML-based estimator to eliminate low-participation features,helps identify the optimal features for enhancing model *** best accuracies of the ANFIS,SVM,RF,and 1dCNN models with meticulous featuring process achieve around 90%,96%,91%,and 93%,*** analysis using the MHEALTH dataset showcases the 1dCNN model’s remarkable perfect accuracy(100%),while the RF,SVM,and ANFIS models equipped with selected features achieve accuracies of 99.8%,99.7%,and 96.5%,***,when applied to the WISDM dataset,the DL-based and ML-based models attain accuracies of 91.4%and 87.3%,respectively,aligning with prior research *** conclusion,the proposed framework yields HAR models with commendable performance metrics,ex.ibiting its suitability for integration into the healthcare services system through AI-driven applications.

关键词： Human activity recognition artificial intelligence support vector machine random forest adaptive neuro-fuzzy inference system convolution neural network recursive feature elimination

Development and validation of a nomogram to predict allograft survival after pediatric liver transplantation

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World Journal of Pediatrics 2024年第3期20卷 239-249页

作者： Guang-x.ang Gu shu-Ting Pan yi-Chen Fan Chen Chen Qiang x.a Department of Liver Surgery Renji HospitalShanghai Jiaotong University School of MedicineNo.160 Pujian RoadPudong New DistrictShanghai 200128China Department of Liver Transplantation Sun Yet-Sen Memorial HospitalSun Yat-Sen UniversityNo.107 Yanjiang West RoadGuangzhou 510080China Clinical Center for Investigation Renji HospitalShanghai Jiaotong University School of MedicineShanghaiChina Department of Anesthesiology Renji HospitalShanghai Jiaotong University School of MedicineShanghaiChina

Background Liver transplantation is the main treatment for cholestatic liver disease and some metabolic liver diseases in ***,no accurate prediction model to determine the survival probability of grafts prior to surgery *** study aimed to develop an effective prognostic model for allograft survival after pediatric liver *** This retrospective cohort study included 2032 patients who underwent pediatric liver transplantation between January 1,2006,and January 1,2020.A nomogram was developed using Cox.regression and validated based on bootstrap *** and discriminatory accuracies were determined using the concordance index.and visualized using calibration curves;net benefits were calculated for model *** online Shiny application was developed for easy access to the *** Multivariable analysis demonstrated that preoperative diagnosis,recipient age,body weight,graft type,preoperative total bilirubin,interleukin-1β,portal venous blood flow direction,spleen thickness,and the presence of heart disease and cholangitis were independent factors for survival,all of which were selected in the *** of the nomogram indicated that the 1-,3-,and 5-year predicted survival rates agreed with the actual survival *** concordance indices for graft survival at 1,3,and 5 years were 0.776,0.757,and 0.753,respectively,which were significantly higher than those of the Pediatric End-Stage Liver Disease and Child-Pugh scoring *** allograft dysfunction risk of a recipient could be easily predicted using the following URL:https://***/ASPELT/l Conclusion The allograft survival after pediatric liver transplantation(ASPELT)score model can effectively predict the graft survival rate after liver transplantation in children,providing a simple and convenient evaluation method for clinicians and patients.

关键词： Allograft survival Nomogram Pediatric liver transplantation

Risk Assessment of Deep-Water Horizontal x.Tree Installation

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China Ocean Engineering 2024年第2期38卷 210-220页

作者： MENG Wen-bo FU Guang-ming HUANG yi LIU shu-jie HUANG Liang GAOYong-hai CNOOC China Limited Zhanjiang BranchZhanjiang 524057China Key Laboratory of Unconventional Oil and Gas Development Ministry of Education(China University of Petroleum(East China))Qingdao 266580China

Due to the high potential risk and many influencing factors of subsea horizontal x.tree installation,to guarantee the successful completion of sea trials of domestic subsea horizontal x.trees,this paper established a modular risk evaluation model based on a fuzzy fault ***,through the analysis of the main process oftree down and combining the Offshore&Onshore Reliability Data(OREDA)failure statistics and the operation procedure and the data provided by the job,the fault tree model of risk analysis of the tree down installation was ***,by introducing the natural language of ex.ert comprehensive evaluation and combining fuzzy principles,quantitative analysis was carried out,and the fuzzy number was used to calculate the failure probability of a basic event and the occurrence probability of a top ***,through a sensitivity analysis of basic events,the basic events of top events significantly affected were determined,and risk control and prevention measures for the corresponding high-risk factors were proposed for subsea horizontal x.tree down installation.

关键词： subsea horizontal x.tree risk assessment fuzzy fault tree modular risk evaluation model

Mg-Al-hydrotalcite with alkaline sites protects Ni/KIT-6 from formation of amorphous coke in glycerol steam reforming via tailoring reaction intermediates

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Frontiers of Chemical Science and Engineering 2024年第4期18卷 25-39页

作者： Yunyu Guo yiran Wang Yuewen Shao shu Zhang yi Wang Song Hu Jun x.ang x.n Hu School of Material Science and Engineering University of JinanJinan 250022China Joint International Research Laboratory of Biomass Energy and Materials College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan 430074China

During steam reforming,the performance of a catalyst and amount/property of coke are closely related to reaction intermediates reaching surface of a ***,modification of reaction intermediates by placing Mg-Al-hydrotalcite above Ni/KIT-6 catalyst in steam reforming of glycerol was conducted at 300 to 600°*** results revealed that the catalytic activity of Ni/KIT-6 in the lower bed was enhanced with either Mg1-Al5-hydrotalcite(containing more acidic sites)or Mg5-Al1-hydrotalcite(containing more alkaline sites)as upper-layer *** in situ infrared characterization of steam reforming demonstrated that Mg-Al-hydrotalcite catalyzed the deox.genation of glycerol,facilitating the reforming of the partially deox.genated intermediates over Ni/***-Al-hydrotalcite as protective catalyst,however,did not protect the Ni/KIT-6 from formation of more ***,this did not lead to further deactivation of Ni/KIT-6 while Mg5-Al1-hydrotalcite even substantially enhanced the catalytic stability,even though the coke was much more significant than that in the use of single Ni/KIT-6(52.7%vs.28.6%).The reason beneath this was change of the property of coke from more aliphatic to more ***5-Al1-hydrotalcite catalyzed dehydration of glycerol,producing dominantly reaction intermediates bearing C=C,which formed the catalytic coke of with carbon nanotube as the main form with smooth outer walls as well as higher aromaticity,C/H ratio,crystallinity,crystal carbon size,thermal stability,and resistivity toward ox.dation on Ni/KIT-6 in the lower *** comparison,the abundance of acidic sites on Mg1-Al5-hydrotalcite catalyzed the formation of more ox.gen-containing species,leading to the formation of carbon nanotubes of rough surface on Ni/KIT-6.

关键词： steam reforming of glycerol Mg-Alhydrotalcite sacrificial catalyst reaction intermediates property of coke

Aero-Hydro-Elastic-Servo Modeling and Dynamic Response Analysis of A Monopile Offshore Wind Turbine Under Different Operating Scenarios

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China Ocean Engineering 2024年第3期38卷 379-393页

作者： x.E shuang-yi GAO Jian LI Yong-ran JIANG shu-x.n ZHANG Cheng-lin HE Jiao College of Mechanical Engineering Chongqing University of TechnologyChongqing 400044China Beijing Institute of Precision Mechatronics and Controls Beijing 100076China College of Mechanical and Vehicle Engineering Chongqing UniversityChongqing 400044China Fishery Machinery and Instrument Research Institute Chinese Academy of Fishery SciencesShanghai 200092China School of Mechanical and Power Engineering Chongqing University of Science&TechnologyChongqing 401331China

This paper constructs a coupled aero-hydro-elastic-servo simulation framework for a monopile offshore wind turbine(OWT).In this framework,a detailed multi-body dynamics model of the monopile OWT including the gearbox.blades,tower and other components(nacelle,hub,bedplate,etc.)has been ex.licitly *** effects of pile−soil interaction,controller and operational conditions on the turbine dynamic responses are studied systematically in time domain and frequency *** results show that(1)a comprehensive drivetrain model has the capability to provide a more precise representation of the complex.dynamic characteristics ex.ibited by drivetrain components,which can be used as the basis for further study on the dynamic characteristics of the drivetrain.(2)The pile−soil interaction can influence the wind turbine dynamic responses,particularly under the parked condition.(3)The effect of the pile−soil interaction on tower responses is more significant than that on blade responses.(4)The use of the controller can substantially affect the rotor characteristics,which in turn influences the turbine dynamic responses.(5)The tower and blade displacements under the operational condition are much larger than those under the parked *** model and methodology presented in this study demonstrate potential for ex.mining complex.dynamic behaviors of the monopile *** ensure accuracy and precision,it is imperative to construct a detailed model of the wind turbine system,while also taking into account simulation efficiency.

关键词： offshore wind turbine(OWT) pile−soil interaction dynamic response parked condition operating condition

Understand the Temperature Sensing Behavior of Solid-state Polymerized PEDOT Hybrid Based on x.ray Scattering Studies

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Chinese Journal of Polymer Science 2024年第1期42卷 105-112,I0010页

作者： Zhen-Hang He Guang-Feng Liu Ze-Kun Zhou Zhen Liu yi-shu Zeng Peng Zhang School of Materials Science and Engineering Key Laboratory for Polymeric Composite and Functional Materials of Ministry of EducationSun Yat-sen UniversityGuangzhou 510275China Shanghai Advanced Research Institute(Zhangjiang Laboratory) Chinese Academy of SciencesShanghai 201204China

Poly(3,4-ethylenediox.thiophene)(PEDOT) is one of the most successful conductive polymers that recently has been used in wearable sensors for human health monitoring. In this work, we prepared a series of PEDOT hybrids consisting of PEDOT, sodium poly(styrene sulfonate)(PSSNa) and polyethylene ox.de(PEO), and their preparation could be scaled-up via an adapted solid-state polymerization process. The resistance of the as-prepared PEDOT:PSS/PEO hybrid shows clear temperature response, i.e., it decreases almost linearly with the temperature increase. To understand this phenomenon, the in situ synchrotron radiation wide-and small-angle x.ray scattering(WAx./SAx.) characterizations were undertaken to study the temperature-dependent microstructure change of the PEDOT:PSS/PEO hybrid. It demonstrated that PEDOT formed conductive paths in the hybrids, which were not destroyed by the PEO crystallization. As temperature increased, the PEO crystals' melting and the accompanying reorganization of PEDOT chains endowed the hybrid sample temperature responsiveness. Based on these fundamental knowledges, the hybrid materials were used to fabricate flex.ble wearable sensor that showing temperature sensing performance with an accuracy of 1 ℃. These findings shed lights on the scalable manufacturing of wearable sensors for body temperature monitoring.

关键词： Solid-state polymerization PEDOT hybrid Structure-property correlation x.ray scattering