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Distributed Region Tracking and Perimeter Surveillance for Second-Order Multi-Agent Systems in Star-Shaped Sets

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Journal of Systems Science & Complexity 2024年第5期37卷 1995-2020页

作者： SHANG Juan mo Lipo MI Rongxin CAO Xianbing School of Mathematics and statistics Beijing Technology and Business UniversityBeijing 100048China The department of Foundation Shijiazhuang Institute of Railway TechnologyShijiazhuang 050041China School of Computer and Artificial Intelligence Beijing Technology and Business UniversityBeijing 100048China Research Centre for Agri-Product Quality Traceability Beijing Technology and Business UniversityBeijing 100048China Coordination Center of China National Computer Network Emergency Response Technical TeamBeijing 100029China

This paper investigates region tracking and perimeter surveillance of second-order multiagent systems,where all agents move within a star-shaped ***,by coordination transformations,the region tracking problem is converted from the star-shaped sets to a circular *** authors employ communication and collaboration to complete region tracking and perimeter surveillance tasks,and then revert back to the star-shaped set by using inverse ***,the authors propose a distributed control strategy based on attractive and interaction potential functions,under which all agents can quickly track a given circular region and move around the ***,the authors validate the effectiveness and performance advantages of the proposed method through simulation experiments.

关键词： Distributed control multi-agent systems star-shaped sets target tracking

Efficient estimation for additive hazards regression with bivariate current status data

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Science China Mathematics 2012年第4期55卷 763-774页

作者： TONG XingWei 1,,HU Tao 2 & SUN JianGuo 3,4 1 School of Mathematical Sciences,Beijing Normal university,Beijing 100875,China 2 School of Mathematical Sciences,Capital Normal university,Beijing 100048,China 3 School of Mathematics,Jilin university,Changchun 130012,China 4 department of statistics,university of missouri,columbia,mo 652.1,usa 1. School of Mathematical Sciences Beijing Normal University Beijing 100875 China2. School of Mathematical Sciences Capital Normal University Beijing 100048 China3. School of Mathematics Jilin University Changchun 130012 China4. Department of Statistics University of Missouri Columbia MO 65211 USA

This paper discusses efficient estimation for the additive hazards regression model when only bivariate current status data are available. Current status data occur in many fields including demographical studies and tumorigenicity experiments （Keiding, 1991; Sun, 2006） and several approaches have been proposed for the additive hazards model with univariate current status data （Linet M., 1998; Martinussen and Scheike, 2002）. For bivariate data, in addition to facing the same problems as those with univariate data, one needs to deal with the association or correlation between two related failure time variables of interest. For this, we employ the copula model and an efficient estimation procedure is developed for inference. Simulation studies are performed to evaluate the proposed estimates and suggest that the approach works well in practical situations. An illustrative example is provided.

关键词： bivariate current status data copula model counting processes efficient estimation joint survivalfunction

Editorial: Welcome Message from Editor-in-Chief, Xuming mo

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Congenital Heart Disease 2024年第1期19卷 1-3页

作者： Xuming mo department of Cardiothoracic Surgery Children’s Hospital of Nanjing Medical UniversityNanjing210008China

1 Introduction The release of the most recent volume of Congenital Heart Disease(CHD)(Issue 19,Volume 1,2024)coincides with my assumption of the role of Co-Editor-In-Chief for CHD.I would like to express my appreciation to CHD for providing me with the opportunity to use the Editorial page.I took on this responsibility on November 18,2023.I would like to take this opportunity to share reflections and convey my *** in 2006,CHD stands as the pioneering professional periodical exclusively dedicated to the exploration and treatment of congenital cardiac abnormalities across all age *** paramount goal is to elevate the scholarly and educational dimension of CHD,driven by an unwavering commitment to provide optimal,holistic cardiac care to patients spanning infancy to *** commitment remains steadfast,with a focus on community service,research,and education quality,regardless of the patient’s financial situation.

关键词： cardiac education release

A comprehensive review on microchannel heat sinks for electronics cooling

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International Journal of Extreme Manufacturing 2024年第2期6卷 133-162页

作者： Zhi-Qiang Yu mo-Tong Li Bing-Yang Cao Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084People’s Republic of China

The heat generation of electronic devices is increasing dramatically,which causes a serious bottleneck in the thermal management of electronics,and overheating will result in performance deterioration and even device *** the development of micro-machining technologies,the microchannel heat sink(MCHS)has become one of the best ways to remove the considerable amount of heat generated by high-power *** has the advantages of large specific surface area,small size,coolant saving and high heat transfer *** paper comprehensively takes an overview of the research progress in MCHSs and generalizes the hotspots and bottlenecks of this *** heat transfer mechanisms and performances of different channel structures,coolants,channel materials and some other influencing factors are ***,this paper classifies the heat transfer enhancement technology and reviews the related studies on both the single-phase and phase-change flow and heat *** comprehensive review is expected to provide a theoretical reference and technical guidance for further research and application of MCHSs in the future.

关键词： microchannel heat sink thermal management of electronics microscale heat transfer heat transfer enhancement

Navigation Finsler metrics on a gradient Ricci soliton

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 266-275页

作者： LI Ying mo Xiao-huan WANG Xiao-yang department of Applied Mathematics Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Pure and Applied Mathematics School of Mathematical SciencesPeking UniversityBeijing 100871China School of Mathematics and statistics Beijing Institute of TechnologyBeijing 100081China

In this paper,we study a class of Finsler metrics defined by a vector field on a gradient Ricci *** obtain a necessary and sufficient condition for these Finsler metrics on a compact gradient Ricci soliton to be of isotropic S-curvature by establishing a new integral *** we determine the Ricci curvature of navigation Finsler metrics of isotropic S-curvature on a gradient Ricci soliton generalizing result only known in the case when such soliton is of Einstein *** its application,we obtain the Ricci curvature of all navigation Finsler metrics of isotropic S-curvature on Gaussian shrinking soliton.

关键词： gradient Ricci soliton navigation Finsler metric isotropic S-curvature Ricci curvature Gaussian shrinking soliton

Giant low-field reversible magnetocaloric effect at liquid helium temperature of niobium and iron co-substituted EuTiO_(3) compounds

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Journal of Rare Earths 2024年第4期42卷 710-715页

作者： Zhihong Hao Quanyi Liu Huicai Xie Yan Zhang Zhaojun mo School of Rare Earth and New Materials Engineering Ganzhou Innovation Center of Rare Earth Permanent Magnet Material Advanced Manufacturing and Intelligent Equipment TechnologyGannan University of Science and TechnologyGanzhou341000China Ganjiang Innovation Academy Chinese Academy of SciencesGanzhou34119China School of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024China

Giant magnetocaloric effect(MCE)materials in the liquid helium temperature region have attracted a lot of attention in the field of low-temperature magnetic refrigeration(MR).In this study,a series of niobium(Nb)and iron(Fe)co-substituted EuTiO_(3) perovskites with cubic structure(space group pm3m)was successfully fabricated,and their magnetic properties as well as cryogenic magnetocaloric effects were investigated in *** expected,the introduction of Nb and Fe can significantly modulate the magnetic phase transition and magnetocaloric effect of the EuTiO_(3) *** increasing Fe concentration,two local minima corresponding to the AFM-FM magnetic phase transition near 5.0 K and FM-PM transition near 10 K with no hysteresis in the thermomagnetic curves are observed,which is attributed to an enhancement of FM *** the same time,the gradually widened-ΔSM-T curves and the two peaks with a broad shoulder lead to considerable refrigeration capacity(RC).With the field change ofΔH=2 T,the calculated values of-ΔS_(M)^(max) for the EuTi_(0.9375-x)Nb_(0.0625)Fe_(x)O_(3)(x=0.075,0.1,0.125,0.15)compounds are 24.2,17.6,14.5 and 14.0 J/(kg·K),*** corresponding RC values were calculated to be 144.6,138.3,151.2 and 159 J/kg,***,the values of-ΔS_(M)^(max) for EuTi_(0.8625)Nb_(0.0625)Fe_(0.075)O_(3) are 8.6 and 15.1 J/(kg·K)under low field changes of 0.5 and 1 T,*** giant low-field reversible magnetocaloric effect makes them attractive candidates for magnetic refrigeration in the liquid helium temperature region.

关键词： Magnetocaloric effect Refrigeration capacity Magnetic entropy change Rareearths

Prediction and validation of diffusive uptake rates for indoor volatile organic compounds in axial passive samplers

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Energy and Built Environment 2024年第1期5卷 24-31页

作者： Yan Wang Tao Yu Jinhan mo department of Building Science Tsinghua UniversityBeijing 100084China Beijing Key Laboratory of Indoor Air Quality Evaluation and Control Beijing 100084China Wuhan Second Ship Design and Research Institute Wuhan 430205China School of Energy and Power Engineering Beihang UniversityBeijing 100191China Key Laboratory of Eco Planning&Green Building Ministry of Education(Tsinghua University)Beijing 100084China

The diffusive uptake rate is essential for using passive samplers to measure indoor volatile organic compounds(VOCs).The traditional theoretical model of passive samplers requires available regression formulas of uptake rates and physicochemical properties of adsorbents to predict the uptake ***,it is difficult to obtain the uptake rates of different VOCs under different sampling periods,and it is also difficult to obtain the physical parameters of adsorbents accurately and *** study provides a reliable numerical prediction method of diffusive uptake rates of *** modeling was based on the standard automated thermal desorption(ATD)tubes packed with Tenax TA and the mass transfer process during *** experimental determinations of toluene uptake rate are carried out to verify the prediction *** uptake rates of typical indoor VOCs are obtained from the literature to calibrate the key apparent parameters in the model by statistical regression *** predicted model can provide the VOC diffusive uptake rates under different sampling duration with an average deviation of less than 5%.This study can provide the basis for fast and accurate prediction of diffusive uptake rates for various VOC pollutants in built environments.

关键词： Indoor air quality Diffusive uptake rate Prediction model Sampling Adsorption

Recent Advances of Imide-Functionalized Polymer Donors for Non-fullerene Solar Cells

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Chinese Journal of Chemistry 2024年第15期42卷 1759-1780页

作者： Huijuan Wang Songmin mo Dongyan Li Qinghe Wu department of Chemistry and Key(Guangdong-Hong Kong Joint)Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Shantou UniversityShantouGuangdong 515063China

In recent years,there has been a shift towards using non-fullerene electron acceptors in organic solar cells(osCs)as a replacement for fullerene *** change requires polymer donors that possess compatible physical properties,such as absorption range,Homo energy level,miscibility,and ***,the high cost and poor batch-to-batch reproducibility of polymer donors also hinder future large-scale *** emphasize the need to explore alternative types of polymer *** imide-functionalized building units possess several key attributes that make their polymers highly promising for non-fullerene *** attributes include ease of synthesis,strong electron-withdrawing ability,rigid and co-planar structure,and the ability to easily tune solubility through imide side *** this review,we summarized the synthetic routes of imide building units,and the structural evolution of imide-functionalized polymer donors by focusing on the effects of polymer structure on their physical,optoelectronic,and photovoltaic *** hope that this mini-review will serve as a catalyst for future research on imide-functionalized polymers toward high-performance,cost-effective,and durable organic solar cells(oscs).

关键词： Imide Polymer donors Organic solar cells Synthetic routes Polymer structure evolution

A high aspect ratio surface micromachined accelerometer based on a SiC-CNT composite material

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Microsystems & Nanoengineering 2024年第2期10卷 219-230页

作者： Jiarui mo Shreyas Shankar Roberto Pezone Guoqi Zhang Sten Vollebregt Laboratory of Electronic Components Technology and Materials(ECTM)Department of MicroelectronicsDelft University of TechnologyDelftThe Netherlands

Silicon carbide(SiC)is recognized as an excellent material for microelectromechanical systems(MEMS),especially those operating in challenging environments,such as high temperature,high radiation,and corrosive ***,SiC bulk micromachining is still a challenge,which hinders the development of complex SiC *** address this problem,we present the use of a carbon nanotube(CNT)array coated with amorphous SiC(a-SiC)as an alternative composite material to enable high aspect ratio(HAR)surface *** using a prepatterned catalyst layer,a HAR CNT array can be grown as a structural template and then densified by uniformly filling the CNT bundle with LPCVD *** electrical properties of the resulting SiC-CNT composite were characterized,and the results indicated that the electrical resistivity was dominated by the *** demonstrate the use of this composite in MEMS applications,a capacitive accelerometer was designed,fabricated,and *** fabrication results showed that the composite is fully compatible with the manufacturing of surface micromachining *** Young’s modulus of the composite was extracted from the measured spring constant,and the results show a great improvement in the mechanical properties of the CNTs after coating with *** accelerometer was electrically characterized,and its functionality was confirmed using a mechanical shaker.

关键词： composite surface electrical