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Nondegenerate Soliton Solutions of(2+1)-Dimensional Multi-Component Maccari System

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Chinese Physics Letters 2024年第6期41卷 11-17页

作者：孟勇方乒乒林机 Department of Physics Zhejiang Normal UniversityJinhua 321004China

For a multi-component Maccari system with two spatial dimensions,nondegenerate one-soliton and two-soliton solutions are obtained with the bilinear *** can be seen by drawing the spatial graphs of nondegenerate solitons that the real component of the system shows a cross-shaped structure,while the two solitons of the complex component show a multi-solitoff *** the same time,the asymptotic analysis of the interaction behavior of the two solitons is conducted,and it is found that under partially nondegenerate conditions,the real and complex components of the system experience elastic collision and inelastic collision,respectively.

关键词： structure. degenerate soliton

Helmholtz decomposition with a scalar Poisson equation in elastic anisotropic media

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Petroleum Science 2024年第3期21卷 1597-1610页

作者： xin-Yu Fang Gang Yao Qing-Qing Zheng Ping-Min Zhang Di Wu Feng-lin Niu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum (Beijing) Unconventional Petroleum Research Institute China University of Petroleum (Beijing) Department of Mathematics College of Science China University of Petroleum (Beijing) College of Geophysics China University of Petroleum (Beijing) Department of Earth Environmental and Planetary Sciences Rice University

P-and S-wave separation plays an important role in elastic reverse-time migration. It can reduce the artifacts caused by crosstalk between different modes and improve image quality. In addition, P-and Swave separation can also be used to better understand and distinguish wave types in complex media. At present, the methods for separating wave modes in anisotropic media mainly include spatial nonstationary filtering, low-rank approximation, and vector Poisson equation. Most of these methods require multiple Fourier transforms or the calculation of large matrices, which require high computational costs for problems with large scale. In this paper, an efficient method is proposed to separate the wave mode for anisotropic media by using a scalar anisotropic Poisson operator in the spatial *** 2D problems, the computational complexity required by this method is 1/2 of the methods based on solving a vector Poisson equation. Therefore, compared with existing methods based on pseudoHelmholtz decomposition operators, this method can significantly reduce the computational cost. Numerical examples also show that the P and S waves decomposed by this method not only have the correct amplitude and phase relative to the input wavefield but also can reduce the computational complexity significantly.

关键词： Anisotropic media Scalar anisotropic Poisson equation Improved elastic wavefield decomposition

A Real-time Lithological Identification Method based on SMOTE-Tomek and ICSA Optimization

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 518-530页

作者： DENG Song PAN Haoyu LI Chaowei YAN Xiaopeng WANG Jiangshuai SHI lin PEI Chunyu CAI meng College of Petroleum Engineering Changzhou UniversityChangzhouJiangsu 213000China

In petroleum engineering,real-time lithology identification is very important for reservoir evaluation,drilling decisions and petroleum geological exploration.A lithology identification method while drilling based on machine learning and mud logging data is studied in this *** method can effectively utilize downhole parameters collected in real-time during drilling,to identify lithology in real-time and provide a reference for optimization of drilling *** the imbalance of lithology samples,the synthetic minority over-sampling technique(SMOTE)and Tomek link were used to balance the sample number of five ***,this paper introduces Tent map,random opposition-based learning and dynamic perceived probability to the original crow search algorithm(CSA),and establishes an improved crow search algorithm(ICSA).In this paper,ICSA is used to optimize the hyperparameter combination of random forest(RF),extremely random trees(ET),extreme gradient boosting(XGB),and light gradient boosting machine(LGBM)*** addition,this study combines the recognition advantages of the four *** accuracy of lithology identification by the weighted average probability model reaches *** study of this paper realizes high-precision real-time lithology identification method,which can provide lithology reference for the drilling process.

关键词： mud logging data real-time lithological identification improved crow search algorithm petroleum geological exploration SMOTE-Tomek

Reaction behavior of MgO refractory with high-Mn and high-Al steel

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Journal of Iron and Steel Research(International) 2024年第6期31卷 1389-1398页

作者： ling-zhong Kong lin Zu Jie Yang Xi-min Zang xin Yang Ming Kang School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina

To understand the mechanism of the interfacial reaction between high-Mn and high-Al steel and MgO refractory,a series of laboratory experiments as well as thermodynamic calculations were *** effects of Mn and Al contents in the steel and the reaction time on the interfacial reaction were *** was observed that the erosion of the MgO refractory is caused by the reaction of Al and Mn in the steel with MgO in the refractory,which would lead to the formation of(Mn,Mg)O·Al_(2)O_(3) spinel and(Mn,Mg)O solid *** formation mechanism of the spinel and solid solution is as *** Al in the steel firstly reacts with MgO in the refractory to generate MgO·Al_(2)O_(3) spinel,and then,the spinel reacts with Mn in the steel to form(Mn,Mg)O·Al_(2)O_(3) ***,the MnO in the spinel reacts with the MgO in the inner refractory to form(Mn,Mg)O solid *** addition,only(Mn,Mg)O·Al_(2)O_(3) spinel is present in the interfacial reaction layer of the refractory when the Al content in the steel is sufficient.

关键词： High-Mn high-Al steel MgO refractory Reaction behavior Spinel

Bionic immunoactivator copresenting autophagy promoting and costimulatory molecules for synergistic cancer immunotherapy

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Nano Research 2024年第3期17卷 1710-1724页

作者： Yiwei Peng Yiliang Yang Zhenzhen Yang Datong Gao Jiajia Li Qi Sun Yitian Du meng lin Xianrong Qi Beijing Key Laboratory of Molecular Pharmaceutics and New Drug Delivery System School of Pharmaceutical SciencesPeking UniversityBeijing 100191China

Immunotherapy has great promise in improving malignant tumor ***,the efficacy of existing strategies is often limited by the immunosuppressive ***,we demonstrate an in situ bionic immunoactivator,PLT-Bec1/DTA-1,with possessed natural advantages of platelets for tumor recruitment and activation,on which DTA-1(CD357 monoclonal antibody)and Bec1 were tethered as combined immune ***-Bec1/DTA-1,as a self-triggered release repository,can deliver the pre-tethered Bec1 and DTA-1 deeply through the secretion of platelet microparticles(PMPs),thereby cooperate tacitly and exhibit superiority in immune activation of dendritic cells(DCs)and T cells via autophagy inducibility,coupled with glucocorticoid-induced tumor necrosis factor receptor(GITR)-triggered T_(Reg) suppression,remodeled the immunosuppressive network of tumor ***-Bec1/DTA-1 promoted antigen presentation and T cell proliferation,and alleviated the low activity state of bone marrow-derived dendritic cells(BMDCs)in tumor suppressive ***-Bec1/DTA-1 inhibited tumor recurrence(5-and 13-fold lower of control group in tumor volume)and CD8^(+)T/T_(Reg) ratio(6.3-and 8.8-fold *** group)in mouse tumor model after intravenous or subcutaneous ***,PLT-Bec1/DTA-1 prevented tumor colonization in lung through in situ immune activation,and was slightly superior to the combined of Bec1 and *** findings highlight the promise of delivering immunostimulatory payloads via bionic carriers,eliciting automatic in situ activation of effector immune cells in tumor microenvironment for tumor *** these results provide promising prospects into the application of immunoactivator in improving cancer synergistic immunotherapy to overcome the bottlenecks in clinic.

关键词： in situ bionic immunoactivator autophagy glucocorticoid-induced tumor necrosis factor receptor(GITR)agonist platelets and platelet microparticles cancer immunotherapy

Two Ramsey-Turán Numbers of Small Independence Numbers

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Acta Mathematicae Applicatae Sinica 2024年

作者： xin-yu HU Qi-zhong lin Center for Discrete Mathematics Fuzhou University

Given a forbidden graph H and a function f(n), the Ramsey-Turán number RT (n, H, f (n)) is the maximum number of edges of an H-free graph on n vertices with independence number less than f (n).For graphs G and H, the Ramsey number R(G, H) is the minimum integer N such that any red/blue edge coloring of the complete graph KNcontains either a red G or a blue H. Denote G+H by the join graph obtained from disjoint G and H by adding all edges between them completely. We first show that for any fixed graph H, if there are two constants p:=p(H)> 0 and q:=q(H)> 1 such that R(H, Kn)≤(pnq)/(log n)q-1, then RT(n, K2+H, o(n1/q(log n)1-1/q))=o(n2), which extends several previous results. Moreover, we show that for any fixed forest F of order k≥3, and for any 0 <δ <1 and sufficiently large n, RT(n, F+F, nδ)≤n(2-(1-δ)/「(k-1)(2-δ)/(1-δ)」).As a corollary, we have an upper bound for RT(n, K2,2,2, nδ) for any 0 <δ <1.

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Iridium-Catalyzed Asymmetric Hydrogenation of Dialkyl Imines

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CCS Chemistry 2024年第4期6卷 905-911页

作者： Zheng Wang xin-Yi Yang Yue Xu Qi-lin Zhou State Key Laboratory and Institute of Elemento-Organic Chemistry College of ChemistryFrontiers Science Center for New Organic MatterNankai UniversityTianjin 300071

Asymmetric hydrogenation of dialkyl imines to chiral amines is difficult because the two alkyls of imines are so similar in spatial and electronic structure that chiral catalysts are difficult to distinguish between *** this study,we described an asymmetric hydrogenation of dialkyl imines by a chiral iridium catalyst containing spiro phosphine-amine-phosphine *** precisely adjusting the chiral pocket of catalyst,a highly efficient catalyst was *** this catalyst,a variety of dialkyl imines were hydrogenated to chiral amines with high yield and enantioselectivity.

关键词： spiro PNP ligand iridium catalyst enantioselective hydrogenation dialkyl imines chiral amines

Hot deformation behavior and microstructure evolution of GH3536-TiBcomposites fabricated by powder metallurgy

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Science China Technological Sciences 2024年

作者： ZHOU ShiPeng WANG Shuai HUANG LuJun ZHANG Rui CHEN xin meng FanChao CHEN Run SUN FengBo WANG CunYu GENG lin School of Materials Science and Engineering Harbin Institute of Technology State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Waikato Centre for Advanced Materials and Manufacturing School of Engineering University of Waikato

The hot deformation behavior and microstructure evolution of GH3536-TiB2composites fabricated by powder metallurgy(PM)were examined in the temperature range of 950–1150°C and strain rate range of 0.001–1s-1. The hot compression stress-strain curves and the constitutive equation were obtained. In addition, the hot processing map was drawn, which indicated that the appropriate hot working window was 950–1050°C/0.001–0.1 s-1and 1050–1100°C/0.001–0.01 s-1. The microstructure analysis showed that the splitting and spheroidization of M3B2led to a decrease in size and volume fraction at 950–1100°C. At 1150°C,the eutectic microstructure of M3B2+ γ was formed due to the dissolution of M3B2, which caused macroscopic cracking of the deformed sample. Additionally, the deformation temperature and the strain rate had little effect on the size and volume fraction of M3B2. Besides, discontinuous dynamic recrystallization(DDRX) and continuous dynamic recrystallization(CDRX) were found in the deformed microstructure, while the former was dominant. Within the test range of this work, the dynamic recrystallization(DRX) fraction of the deformed composites was high due to the bulging nucleation of numerous interfaces. The DRX grain size increased with increasing deformation temperature or decreasing strain rate. Texture analysis showed that the deformation texture of //compression direction RD existed in the matrix when the deformation temperature was below 1100°C, and the texture type became //RD at 1100°C. Additionally, it was also found that the //RD texture was formed in M3B2under the strain rates of 0.1 and 0.01 s-1.

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The Predictability Limit of Oceanic Mesoscale Eddy Tracks in the South China Sea

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Advances in Atmospheric Sciences 2024年第9期41卷 1661-1679页

作者： Hailong LIU Pingxiang CHU Yao meng mengrong DING Pengfei lin Ruiqiang DING Pengfei WANG Weipeng ZHENG LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laoshan Laboratory Qingdao 266237China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Marine Science and Technology College Zhejiang Ocean UniversityZhoushan 316022China State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100872China Center for Monsoon System Research(CMSR) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100190China

Employing the nonlinear local Lyapunov exponent (NLLE) technique, this study assesses the quantitative predictability limit of oceanic mesoscale eddy (OME) tracks utilizing three eddy datasets for both annual and seasonal means. Our findings reveal a discernible predictability limit of approximately 39 days for cyclonic eddies (CEs) and 44 days for anticyclonic eddies (AEs) within the South China Sea (SCS). The predictability limit is related to the OME properties and seasons. The long-lived, large-amplitude, and large-radius OMEs tend to have a higher predictability limit. The predictability limit of AE (CE) tracks is highest in autumn (winter) with 52 (53) days and lowest in spring (summer) with 40 (30) days. The spatial distribution of the predictability limit of OME tracks also has seasonal variations, further finding that the area of higher predictability limits often overlaps with periodic OMEs. Additionally, the predictability limit of periodic OME tracks is about 49 days for both CEs and AEs, which is 5-10 days higher than the mean values. Usually, in the SCS, OMEs characterized by high predictability limit values exhibit more extended and smoother trajectories and often move along the northern slope of the SCS.

关键词： predictability mesoscale eddy nonlinear local Lyapunov exponent South China Sea seasonal variability