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Global Spherically Symmetric Solutions for a Coupled Compressible Navier–Stokes/Allen–Cahn System

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Acta Mathematica Sinica,English Series 2024年第8期40卷 2037-2064页

作者： Chang Ming SONG Jian Lin zhang yuan yuan WANG Department of Applied Mathematics School of Mathematics and Information ScienceZhongyuan University of TechnologyZhengzhou 450007P.R.China

In this paper,we consider the global spherically symmetric solutions for the initial boundary value problem of a coupled compressible Navier–Stokes/Allen–Cahn system which describes the motion of two-phase viscous compressible *** prove the existence and uniqueness of global classical solution,weak solution and strong solution under the assumption of spherically symmetry condition for initial dataρ0 without vacuum state.

关键词： Diffuse interface model global solutions Navier-Stokes equations Allen-Cahn equation spherically symmetry

Long-term changes in radial growth of seven tree species in the mixed broadleaf-Korean pine forest in Northeast China: Are deciduous trees favored by climate change?

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JOURNAL OF FORESTRY RESEARCH 2024年第1期35卷 1-15页

作者： Gong, Xiufang yuan, Danyang zhu, Liangjun Li, Zongshan Wang, Xiaochun Cent South Univ Forestry & Technol Coll Life Sci & Technol Natl Engn Lab Appl Technol Forestry & Ecol South C Changsha 410004 Peoples R China Northeast Forestry Univ Ctr Ecol Res Sch Forestry Harbin 150040 Peoples R China Northeast Forestry Univ Sch Forestry Key Lab Sustainable Forest Ecosyst Management Minist Educ Harbin 150040 Peoples R China Chinese Acad Sci Res Ctr Ecoenvironm Sci State Key Lab Urban & Reg Ecol Beijing 100085 Peoples R China

The role of the temperate mixed broadleaf-Korean pine forest (BKF) in global biogeochemical cycles will depend on how the tree species community responds to climate; however, species-specific responses and vulnerabilities of common trees in BKF to extreme climates are poorly understood. Here we used dendrochronological methods to assess radial growth of seven main tree species (Pinus koraiensis, Picea jezoensis, Abies nephrolepis, Fraxinus mandshurica, Phellodendron amurense, Quercus mongolica, and Ulmus davidiana) in an old-growth BKF in response to climate changes in the Xiaoxing'an Mountains and to improve predictions of changes in the tree species composition. Temperature in most months and winter precipitation significantly negatively affected growth of P. jezoensis and A. nephrolepis, but positively impacted growth of P. koraiensis and the broadleaf species, especially F. mandshurica and U. davidiana. Precipitation and relative humidity in June significantly positively impacted the growth of most tree species. The positive effect of the temperature during the previous non-growing season (PNG) on growth of F. mandshurica and Q. mongolica strengthened significantly with rapid warming around 1981, while the impact of PNG temperature on the growth of P. jezoensis and A. nephrolepis changed from significantly negative to weakly negative or positive at this time. The negative response of radial growth of P. jezoensis and A. nephrolepis to precipitation during the growing season gradually weakened, and the negative response to PNG precipitation was enhanced. Among the studied species, P. koraiensis was the most resistant to drought, and U. davidiana recovered the best after extreme drought. Ulmus davidiana, P. jezoensis and A. nephrolepis were more resistant to extreme cold than the other species. Climate warming generally exacerbated the opposite growth patterns of conifer (decline) and broadleaf (increase) species. Deciduous broadleaf tree species in the old-growth

关键词： Tree rings Extreme climate Resistance and recovery Broad-leaved and Korean pine mixed forest DROUGHT TEMPERATURE RESPONSES KORAIENSIS RESILIENCE DYNAMICS IMPACT XYLEM

Genesis of ultra-deep dolostone and controlling factors of largescale reservoir:A case study of the Sinian Dengying Formation and the Cambrian Longwangmiao Formation in the Sichuan Basin

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Science China Earth Sciences 2024年第7期67卷 2352-2382页

作者： Xi LI Guangyou zhu Zhiyao zhang PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China School of Geosciences Yangtze UniversityWuhan 430100China School of Earth Resoures China University of GeosciencesWuhan 430074China

This paper investigates the origin of ultra-deep dolostone and the factors influencing large-scale dolostone reservoirs,focusing on the Sinian Dengying Formation and the Cambrian Longwangmiao Formation in the Sichuan *** study involves petrology,microscale X-ray diffraction,trace element analysis,and C-O-Sr-Mg isotope experiments to provide a detailed *** research findings indicate that the Dengying and Longwangmiao formations comprise six types of matrix dolostone and four types of *** Dengying Formation,which developed under a sedimentary background of a restricted platform,contains special microbial and microcrystalline *** dolomite grains are small(30μm),high order degree(Min=0.7),small unit cell parameters,high Na content

关键词： Ultra-deep layers Dolostone Supercontinent evolution Microscale geochemistry Dengying Formation Longwangmiao Formation Sichuan Basin

Isolation performances and optimization of triple quasi-zero stiffness isolators

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 124-141页

作者： Yuntian zhang Guangnan zhu Qingjie Cao School of Astronautics Harbin Institute of TechnologyHarbin 150001China

In this paper,triple quasi-zero stiffness(QZS)passive vibration isolators whose restoring force curve has a three-stage softening effect are ***-coupled SD oscillators with three independent geometrical parameters are used as negative stiffness mechanisms to achieve QZS characteristics at the origin and symmetrical positions on both sides of the *** performances of different triple QZS isolators are analyzed to show influences of the selection of QZS regions away from the origin on the range of isolation *** optimizations of system parameters are carried out to get a larger range of small restoring force regions and small stiffness *** performances of two triple QZS isolators are discussed to show the influence of different Pareto optimization solutions through the comparisons with single and double QZS *** showed that triple QZS isolators have both the advantages of single and double QZS isolators which results in better isolation performances under both small and large excitation *** improvement in isolation performances for triple QZS isolators is found with the decrease in average stiffness due to the appearance of two symmetrical QZS regions away from the *** displacements of QZS regions away from the origin result in better isolation performances when excitation amplitude is large,and triple QZS characteristics are similar to double QZS isolators at this *** restoring forces of QZS regions away from the origin lead to better isolation performances when excitation amplitude is small,and triple QZS characteristics are similar to single QZS isolators at this *** with the decrease in average stiffness,the improvement of isolation performances shows a hysteresis phenomenon due to the difference between static and dynamic characteristics.

关键词： triple quasi-zero stiffness vibration isolation Pareto optimization force transmissibility geometrical nonlinear

Camera,LiDAR,and IMU Based Multi-Sensor Fusion SLAM:A Survey

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Tsinghua Science and Technology 2024年第2期29卷 415-429页

作者： Jun zhu Hongyi Li Tao zhang Department of Automation Tsinghua UniversityBeijing 100084China

In recent years,Simultaneous Localization And Mapping(SLAM)technology has prevailed in a wide range of applications,such as autonomous driving,intelligent robots,Augmented Reality(AR),and Virtual Reality(VR).Multi-sensor fusion using the most popular three types of sensors(e.g.,visual sensor,LiDAR sensor,and IMU)is becoming ubiquitous in SLAM,in part because of the complementary sensing capabilities and the inevitable shortages(e.g.,low precision and long-term drift)of the stand-alone sensor in challenging *** this article,we survey thoroughly the research efforts taken in this field and strive to provide a concise but complete review of the related ***,a brief introduction of the state estimator formation in SLAM is ***,the state-of-the-art algorithms of different multi-sensor fusion algorithms are *** we analyze the deficiencies associated with the reviewed approaches and formulate some future research *** paper can be considered as a brief guide to newcomers and a comprehensive reference for experienced researchers and engineers to explore new interesting orientations.

关键词： multi-sensor fusion Simultaneous Localization And Mapping(SLAM) navigation localization

Melittin enhanced intracellular trehalose with synergistic membrane stabilization of macromolecular protectants for cell cryopreservation

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Science China(Technological Sciences) 2024年第4期67卷 1160-1169页

作者： NIU QingJing GAO ShuHui zhu KongYing REN LiXia yuan XiaoYan School of Materials Science and Engineering Tianjin Key Laboratory of Composite and Functional MaterialsTianjin UniversityTianjin 300350China Analysis and Measurement Center Tianjin UniversityTianjin 300072China

Cryopreservation plays an essential role in biobanking and cell therapy,but the physiological toxicity of traditional cryoprotectants such as glycerol and dimethyl sulfoxide(DMSO)has raised safety issues for biomedical ***,a nonreducing disaccharide that accumulates in desiccation-or cold-tolerant organisms,has been considered as a biocompatible ***,a naturally occurring membrane-active cationic peptide,melittin,was utilized to facilitate membraneimpermeable trehalose entry into cells for effective cell ***(ethylene glycol)and poly(vinyl pyrrolidone)were applied as macromolecular protectants to improve the stabilization of cell *** the optimal protocol,the postthaw recovery of human red blood cells in freezing bags at a hematocrit of~50%could achieve 82.9%with favorable cell morphologies and physiological ***,the cryosurvival of L929 fibroblasts reached 84.3%compared to the conventional method using 10%(v/v)*** short,this work by using trehalose and melittin provides a biocompatible solvent-free approach for long-term cryostorage of cells.

关键词： melittin intracellular trehalose membrane stabilization macromolecular protectants cell cryopreservation

Stabilization of cathode electrolyte interphase for aqueous zinc-ion batteries

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Journal of Energy Chemistry 2024年第9期96卷 359-386页

作者： Zhenjie Yao Wenyao zhang Junwu zhu Key Laboratory for Soft Chemistry and Functional Materials Ministry of Education Nanjing University of Science and TechnologyNanjing 210094JiangsuChina

Aqueous zinc-ion battery systems are attractive for next-generation energy storage devices,however,the unstable electrode electrolyte interphase,especially cathode electrolyte interphase(CEI),has induced rapid capacity attenuation,insufficient cycle life,and severe safety *** the researching of CEI formation,composition,dynamic structure,and reaction mechanisms would help in understanding the fundamental electrochemistry at CEI such as electron and ion transport processes,further strengthening the specific capacity,rate,and cycle performance of the cathode *** this review,we summarized the latest progress in understanding interfacial reaction mechanisms and ion dynamic behavior,emphasizing the impact of surface-specific adsorption and solvation behaviors on the interface's ultimate structure and chemical ***,the significant challenges that persist in CEI formation mechanisms,such as cathodic dissolution,by-product formation,electrostatic interactions,constrained electrochemical windows,oxygen evolution reaction,overpotentials,phase transitions,and additional factors,were *** challenges are explored to identify triggers contributing to the depletion of active materials and alterations in the composition or state of the ***,with a deep comprehension of interfacial behaviors,the review articulates innovative optimization strategies through a detailed categorization of approaches in electrolyte engineering,cathode engineering,and artificial CEI ***,future challenges and development directions of CEI are *** hope to offer insights for constructing robust CEI films to achieve high performance aqueous zinc-ion batteries.

关键词： Aqueous zinc-ion batteries Cathode-electrolyte interphase Energy storage

Resource Allocation for Cognitive Network Slicing in PD-SCMA System Based on Two-Way Deep Reinforcement Learning

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China Communications 2024年第6期21卷 53-68页

作者： zhang Zhenyu zhang Yong yuan Siyu Cheng Zhenjie School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Work Safety Intelligent Monitoring(Beijing University of Posts and Telecommunications) Beijing 100876China

In this paper,we propose the Two-way Deep Reinforcement Learning(DRL)-Based resource allocation algorithm,which solves the problem of resource allocation in the cognitive downlink network based on the underlay *** users(SUs)in the cognitive network are multiplexed by a new Power Domain Sparse Code Multiple Access(PD-SCMA)scheme,and the physical resources of the cognitive base station are virtualized into two types of slices:enhanced mobile broadband(eMBB)slice and ultrareliable low latency communication(URLLC)*** design the Double Deep Q Network(DDQN)network output the optimal codebook assignment scheme and simultaneously use the Deep Deterministic Policy Gradient(DDPG)network output the optimal power allocation *** objective is to jointly optimize the spectral efficiency of the system and the Quality of Service(QoS)of *** results show that the proposed algorithm outperforms the CNDDQN algorithm and modified JEERA algorithm in terms of spectral efficiency and QoS ***,compared with the Power Domain Non-orthogonal Multiple Access(PD-NOMA)slices and the Sparse Code Multiple Access(SCMA)slices,the PD-SCMA slices can dramatically enhance spectral efficiency and increase the number of accessible users.

关键词： cognitive radio deep reinforcement learning network slicing power-domain non-orthogonal multiple access resource allocation

China's agriculture green development: from concept to actions

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Frontiers of Agricultural Science and Engineering 2024年第1期11卷 20-34页

作者： Haixing zhang yuan FENG Yanxiang JIA Pengqi LIU Yong HOU Jianbo SHEN Qichao zhu Fusuo zhang National Academy of Agriculture Green Development China Agricultural UniversityBeijing 100193China College of Resources and Environmental Sciences China Agricultural UniversityBeijing 100193China Environmental Economics and Natural Resources Group Wageningen University and ResearchP.O.Box 81306700 EW Wageningenthe Netherlands

China has initiated a green transformation plan in 2015, which was soon applied to agriculture, known as the agriculture green development(AGD)initiative, with the goals of achieving food security, high resource use efficiency, and an ecofriendly environment. To assess the agricultural transformation from 1997 to 2020, this paper proposes a national-scale indicator system consisting three dimensions(socioeconomic, food production and eco-environmental) and ten sub-dimensions to quantify the AGD *** study showed that AGD score in China was at a moderate level during 1997–2010, scoring 40 out of 100. During this stage, decreased scores in the sub-dimensions of resource consumption, environmental quality, and environmental cost have offset the improvement in the socioeconomic dimension, resulting in fluctuated scores around 40. In the second stage(2011–2020), China's AGD score improved but still at moderate level, scoring an average of 46.3, with each dimension increasing by 5.3%–25.0%. These results indicate that China has made progress in the agricultural transformation, transitioning from conceptualization to actions through the implementation of various policies and projects. However, the study emphasizes the need for more effort to address the insufficient and unbalanced development, along with the growing eco-environmental challenges, especially the trade-offs among dimensions.

关键词： Agricultural transformation agriculture green development historical trend indicator system theoretical conception