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Optimal Model Average Prediction in Orthogonal Kriging Models

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Journal of Systems Science & Complexity 2024年第3期37卷 1080-1099页

作者： WANG jun HE Jiabei liANG Hua li Xinmin School of Mathematics and Statistics Qingdao UniversityQingdao 266071China Department of Statistics George Washington UniversityWashington DC 20052USA

The main objective of this paper is to consider model averaging methods for kriging *** paper proposes a Mallows model averaging procedure for the orthogonal kriging model and demonstrate the asymptotic optimality of the model averaging estimators in terms of mean square *** studies are conducted to evaluate the performance of the proposed method and compare it with the competitors to demonstrate its *** authors also analyse a real dataset for an illustration.

关键词： Asymptotic optimality Mallows criterion optimal model averaging orthogonal kriging model

Single-emissive white-luminescent quantum dots for generating full-color circularly polarized luminescence

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Science China Chemistry 2024年第11期67卷 3505-3507页

作者： Jinsui li Wendi qin Fanglong Yuan Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education College of Chemistry Beijing Normal University

Circularly polarized luminescence(CPL) has garnered widespread attention in recent years due to its versatile applications, spanning from three-dimensional(3D) displays to quantum-based optical computing and informati...

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Hole cleaning evaluation and installation spacing optimization of cuttings bed remover in extended-reach drilling

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Petroleum Science 2024年第3期21卷 2005-2022页

作者： Shuo Peng Wen-jun Huang De-li Gao MOE Key Laboratory of Petroleum Engineering China University of Petroleum-BeijingBeijing102249China State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBeijing102249China

In extended-reach or long-horizontal drilling,cuttings usually deposit at the bottom of the *** cuttings accumulate to a certain thickness,complex problems such as excessive torque and drag,tubing buckling,and pipe stuck probably occur,which results in a lot of non-productive time and remedial *** bed remover can efficiently destroy deposited cuttings in time through hydraulic and mechanical stirring *** paper aims to build a method for hole cleaning evaluation and installation spacing optimization of cuttings bed remover to improve the wellbore cleaning ***,a Computational Fluid Dynamics approach with Eulerian—Eulerian multiphase model was utilized to investigate the mechanism of cuttings transportation,and a new type of cuttings bed remover was ***,an evaluation method of hole cleaning effect of remover was *** that,the effects of several drilling parameters on hole cleaning including flow rate of drilling fluid,rotational speed of drillpipe,rate of penetration,wellbore size,rheological property of drilling fluid,and remover eccentricity on the performance of cuttings bed remover were *** results demonstrate that the new type of remover with streamline blade performs better than conventional *** efficiency of hole cleaning is greatly improved by increasing the rotational speed of drillpipe,flow rate of drilling fluid,remover eccentricity,and 6 rpm Fann dial reading for drilling *** higher rate of penetration and large wellbore size result in worse hole *** findings can serve as an important guide for the structure optimization design of cuttings bed remover and installation spacing of removers.

关键词： Extended-reach drlling Drilling hydraulics Cuttings transport Hole cleaning Cuttings bed remover

Time-history performance optimization of flapping wing motion using a deep learning based prediction model

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Chinese Journal of Aeronautics 2024年第5期37卷 317-331页

作者： Tianqi WANG liu liU jun li lifang ZENG School of Aeronautics and Astronautics Zhejiang UniversityHangzhou 310027China Huanjiang Laboratory Zhuji 311800China

Flapping Wing Micro Aerial Vehicles(FWMAVs)have caused great concern in various fields because of their high efficiency and *** wing motion is a very important factor that affects the performance of the aircraft,and previous works have always focused on the time-averaged performance ***,the time-history performance is equally important in the design of motion mechanism and flight control *** this paper,a time-history performance optimization framework based on deep learning and multi-island genetic algorithm is presented,which is designed in order to obtain the optimal two-dimensional flapping wing ***,the training dataset for deep learning neural network is constructed based on a validated computational fluid dynamics *** aerodynamic surrogate model for flapping wing is obtained after the convergence of *** surrogate model is tested and proved to be able to accurately and quickly predict the time-history curves of lift,thrust and ***,the optimization framework is used to optimize the flapping wing motion in two specific cases,in which the optimized propulsive efficiencies have been improved by over 40%compared with the ***,a dimensionless parameter C_(variation)is proposed to describe the variation of the time-history characteristics,and it is found that C_(variation)of lift varies significantly even under close time-averaged *** the importance of time-history performance in practical applications,the optimization that integrates the propulsion efficiency as well as C_(variation)is carried *** final optimal flapping wing motion balances good time-averaged and time-history performance.

关键词： FWMAV Flapping wing motion Deep learning Unsteady aerodynamic performance Optimization Time-history curve

Temporal-spatial Generation of Astrocytes in the Developing Diencephalon

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Neuroscience Bulletin 2024年第1期40卷 1-16页

作者： Wentong Hong Pifang Gong Xinjie Pan Zhonggan Ren Yitong liu Guibo Qi jun-liszt li Wenzhi Sun Woo-Ping Ge Chun-li Zhang Shumin Duan Song qin Department of Anatomy Histology and EmbryologySchool of Basic Medical SciencesFudan UniversityShanghai 200032China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Chinese Institute for Brain Research Beijing 102206China School of Basic Medical Sciences Capital Medical UniversityBeijing 100069China Department of Molecular Biology University of Texas Southwestern Medical CenterDallasTexas 75390-9148USA Department of Neurobiology Key Laboratory of Medical Neurobiology of Ministry of Health of ChinaZhejiang University School of MedicineHangzhou 310058China State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science Fudan UniversityShanghai 200032China

tAstrocytes are the largest glial population in the mammalian ***,we have a minimal understanding of astrocyte development,especially fate specification in different regions of the *** lineage tracing of the progenitors of the third ventricle(3V)wall via in-utero electroporation in the embryonic mouse brain,we show the fate specification and migration pattern of astrocytes derived from radial glia along the 3V ***,radial glia located in different regions along the 3V wall of the diencephalon produce distinct cell types:radial glia in the upper region produce astrocytes and those in the lower region produce neurons in the *** genetic fate mapping analysis,we reveal that the first population of astrocytes appears along the zona incerta in the *** occurs at an early time point in the dorsal region relative to that in the ventral region of the developing *** transcriptomic analysis of the region-specific 3V wall and lateral ventricle(LV)wall,we identified cohorts of differentially-expressed genes in the dorsal 3V wall compared to the ventral 3V wall and LV wall that may regulate astrogenesis in the dorsal ***,these results demonstrate that the generation of astrocytes shows a spatiotemporal pattern in the developing mouse diencephalon.

关键词： Radial glia Astrocyte specification lineage tracing Diencephalon Third ventricle

Two-way shape memory effect in a Ti-Zr-Nb-Ta high-temperature shape memory alloy

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Rare Metals 2024年第3期43卷 1257-1262页

作者： Cheng-Yang Xiong Tuo li jun Wang Yan li School of Materials Science and Engineering Beihang UniversityBeijing100191China

The two-way shape memory effect in a Ti-18.5Zr-10Nb-3.5Ta high-temperature shape memory alloy was investigated.X-ray diffraction measurem ent shows that the alloy is composed of orthorhombicα"-martensite.ωphase is not found in Ti-18.5Zr-10Nb-3.5Ta alloy due to the suppressing effect of Ta ***α"-martensite laths are found in the transmission electron microscope observation;after the bending deformation,there appear a lot of *** alloy exhibits a shape memory strain of 3.8%aud a high reverse martensite transformation start temperature of 464 *** maximum two-way shape memory strain of 1.2%is obtained in the alloy with the prebending training strain of 10%.The mechanism can be ascribed to the effect of internal stress field caused by dislocations.

关键词： Ti-Zr Shape memory alloys Two-way shape memory effect

Dual peroxisome proliferator-activated receptorα/δagonists:Hope for the treatment of alcohol-associated liver disease?

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World Journal of Gastroenterology 2024年第37期30卷 4163-4167页

作者： Xin-Yang Zhang qin-jun-Jie Chen Feng Zhu Min li Dan Shang Department of Vascular Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina Department of Hepatobiliary Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina Department of Vascular Surgery Hubei Provincial Hospital of Traditional Chinese MedicineWuhan 430061Hubei ProvinceChina

In this letter,we review the article“Effects of elafibranor on liver fibrosis and gut barrier function in a mouse model of alcohol-associated liver disease”.We focus specifically on the detrimental effects of alcohol-associated liver disease(ALD)on human *** its insidious onset and increasing incidence,increasing awareness of ALD can contribute to reducing the prevalence of liver *** comprises a spectrum of several different disorders,including liver steatosis,steatohepatitis,fibrosis,cirrhosis,and hepatocellular *** pathogenesis of ALD is exceedingly *** studies have shown that peroxisome proliferator-activated receptors(PPARs)regulate lipid metabolism,glucose homeostasis and inflammatory responses within the ***,their dysfunction is a major contributor to the progression of *** is an oral,dual PPARαandδ*** effectiveness of elafibranor in the treatment of ALD remains *** this letter,we emphasize the harm of ALD and the burden it places on ***,we summarize the clinical management of all stages of ALD and present new insights into its pathogenesis and potential therapeutic ***,we discuss the mechanisms of action of PPARαandδagonists,the significance of their antifibrotic effects on ALD and future research directions.

关键词： Alcohol-associated liver disease Fibrosis Antifibrotic effect Elafibranor Peroxisome proliferator-activated receptor

Adaptive coupled-sliding-variable-based finite-time control of composite formation for multi-robot systems

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Science China(Information Sciences) 2024年第10期67卷 244-260页

作者： Xinru MA Hengyu li jun liU Yueying WANG Shaorong XIE jun LUO School of Mechatronic Engineering and Automation Shanghai University School of Mathematics and Computer Application Technology Jining University School of Computer Science Shanghai University College of Mechanical and Vehicle Engineering Chongqing University

This paper focuses on the finite-time control(FTC) of the composite formation consensus(CFC)problems for multi-robot systems(MRSs). The CFC problems are firstly proposed for MRSs under the complex network topology of cooperative or cooperative-competitive networks. Regarding the problems of FTC and CFC on multiple Lagrange systems(MLSs), coupled sliding variables are introduced to deal with the robustness and consistent convergence. Then, the adaptive finite-time protocols are given based on the displacement approaches. With the premised FTC, tender-tracking methods are further developed for the problems of tracking information disparity. Stability analyses of those MLSs mentioned above are clarified with Lyapunov candidates considering the coupled sliding vectors, which provide new verification for tender-tracking systems. Under the given coupled-sliding-variable-based finite-time protocols, MLSs distributively adjust the local formation error to achieve global CFC and perform uniform convergence in time-varying tracking. Finally, simulation experiments are conducted while providing practical solutions for the theoretical results.

关键词： composite formation time-vary tracking information disparity tender-tracking finite-time control nonlinear robots complex networks symmetry consensus

A quantum-enhanced magnetometer using a single high-spin nucleus in silicon

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Chinese Physics B 2024年第9期33卷 110-115页

作者： Tao Xin Ke Zhang jun li Shenzhen Institute for Quantum Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Quantum Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Physikalisch-Technische Bundesanstalt Bundesallee 10038116 BraunschweigGermany Institute of Quantum Precision Measurement State Key Laboratory of Radio Frequency Heterogeneous IntegrationShenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China

Quantum enhanced metrology has the potential to go beyond the standard quantum limit and eventually to the ultimate Heisenberg *** particular,quantum probes prepared in nonclassical coherent states have recently been recognized as a useful resource for ***,there has been considerable interest in constructing magnetic quantum sensors that combine high resolution and high ***,we explore a nanoscale magnetometer with quantum-enhanced sensitivity,based on 123Sb(I=7/2)nuclear spin doped in silicon,that takes advantage of techniques of spin-squeezing and coherent *** the optimal squeezed initial state,the magnetic field sensitivity may be expected to approach 6 aT·Hz^(−1/2)·cm^(−3/2) and 603 nT·Hz^(−1/2) at the single-spin *** magnetic sensor may provide a novel sensitive and high-resolution route to microscopic mapping of magnetic fields as well as other applications.

关键词： quantum magnetometer silicon quantum qubit nuclear electrical resonance