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A Mass-Preserving Characteristic Finite Difference Method For Miscible Displacement Problem

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Advances in Applied Mathematics and Mechanics 2024年第1期16卷 164-180页

作者： Jiansong zhang Yue Yu rong Qin Zhaohui Liu Department of Applied Mathematics China University of PetroleumQingdaoShandong 266580China

In this article,a new characteristic finite difference method is developed for solving miscible displacement problem in porous *** new method combines the characteristic technique with mass-preserving interpolation,not only keeps mass balance but also is of second-order accuracy both in time and *** results are presented to confirm the convergence and the accuracy in time and space.

关键词： The method of characteristics mass-preserving finite difference miscible displacement problem

Application of sparse S transform network with knowledge distillation in seismic attenuation delineation

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Petroleum Science 2024年第4期21卷 2345-2355页

作者： Nai-Hao Liu Yu-Xin zhang Yang Yang rong-Chang Liu Jing-Huai Gao Nan zhang School of Information and Communications Engineering Xi'an Jiaotong University School of Software Engineering Xi'an Jiaotong University PetroChina Research Institute of Petroleum Exploration and Development (RIPED) CNPC Research Institute of Exploration and Development Yumen Oilfield Company CNPC

Time-frequency analysis is a successfully used tool for analyzing the local features of seismic ***, it suffers from several inevitable limitations, such as the restricted time-frequency resolution,the difficulty in selecting parameters, and the low computational efficiency. Inspired by deep learning,we suggest a deep learning-based workflow for seismic time-frequency analysis. The sparse S transform network(SSTNet) is first built to map the relationship between synthetic traces and sparse S transform spectra, which can be easily pre-trained by using synthetic traces and training labels. Next, we introduce knowledge distillation(KD) based transfer learning to re-train SSTNet by using a field data set without training labels, which is named the sparse S transform network with knowledge distillation(KD-SSTNet).In this way, we can effectively calculate the sparse time-frequency spectra of field data and avoid the use of field training labels. To test the availability of the suggested KD-SSTNet, we apply it to field data to estimate seismic attenuation for reservoir characterization and make detailed comparisons with the traditional time-frequency analysis methods.

关键词： S transform Deep learning Knowledge distillation Transfer learning Seismic attenuation delineation

Dynamic analysis of a latent HIV infection model with CTL immune and antibody responses

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International Journal of Biomathematics 2024年第3期17卷 289-316页

作者： Zhiqi zhang Yuming Chen Xia Wang Libin rong School of Mathematics and Statistics Xinyang Normal University XinyangHenan 464000P.R.China Department of Mathematics Wilfrid Laurier University WaterlooONN2L 3C5Canada Department of Mathematics University of Florida GainesvilleFL 32611USA

This paper develops a mathematical model to investigate the Human Immunodeficiency Virus(HIV)infection *** model includes two transmission modes(cell-to-cell and cell-free),two adaptive immune responses(cytotoxic T-lymphocyte(CTL)and antibody),a saturated CTL immune response,and latent HIV *** existence and local stability of equilibria are fully characterized by four reproduction *** sensitivity analyses,we assess the partial rank correlation coefficients of these reproduction numbers and identify that the infection rate via cell-to-cell transmission,the number of new viruses produced by each infected cell during its life cycle,the clearance rate of free virions,and immune parameters have the greatest impact on the reproduction ***,we compare the effects of immune stimulation and cell-to-cell spread on the model's *** findings highlight the significance of adaptive immune responses in increasing the population of uninfected cells and reducing the numbers of latent cells,infected cells,and ***,cell-to-cell transmission is identified as a facilitator of HIV *** analytical and numerical results presented in this study contribute to a better understanding of HIV dynamics and can potentially aid in improving HIV management strategies.

关键词： HIV infection cell-to-cell transmission adaptive immune response latent infection local stability

Regulation of Ti(C,N)deposition on hot surface of refractory in blast furnace hearth

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Journal of Iron and Steel Research International 2024年第6期31卷 1423-1435页

作者： Jian Cao Cui Wang Jjan-liang zhang Ke-xin Jiao guo-hua zhang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

Ti(C,N)concentration was found to be lower on the hearth sidewall of a blast furnace and increased gradually toward the bottom of the blast *** Ti(C,N)protective layer in a blast furnace is ***,the formation of a Ti(C,N)protective layer was promoted by studying the heterogeneous nucleation principle of titanium compounds on different substances and regulation measures for the deposition process of titanium compounds on refractories or *** lattice disregistry between the titanium compounds and the main components in the refractory or the main impurities in the protective layer was calculated using a two-dimensional disregistry equation to study the heterogeneous nucleation principle of titanium *** results revealed that in refractory materials,the heterogeneous nucleation of carbonitride is weak when C,SiO_(2),and Al_(2)O_(3) are used as heterogeneous nucleation substrates,and the heterogeneous nucleation of carbonitride is strong when TiO_(2) and SiC are used as heterogeneous nucleation *** nucleation phases,TiC,TiN,Ti(C_(0.3),N_(0.7)),and Ti(C_(0.5),N_(0.5))have similar heterogeneous nucleation ability in single component refractory,and the type of carbonitride has little effect on the lattice *** impurities in the protective layer as the substrate phases are not conducive to the heterogeneous nucleation of *** CaS was used as the substrate phase,the heterogeneous nucleation ability of carbonitride was the *** carbon and alumina were not conducive to the heterogeneous nucleation of carbonitride,but carbon was more unfavourable than alumina.

关键词： Ti(C,N) Lattice disregistry Lattice constant Heterogeneous nucleation Regulation measure

Hypoxic tumor microenvironment:Destroyer of natural killer cell function

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Chinese Journal of Cancer Research 2024年第2期36卷 138-150页

作者： Yongfei zhang Feifei guo Yufeng Wang Cancer Center the First Hospital of Jilin UniversityChangchun 130021China

In recent years, immunotherapy has made remarkable progress in treating certain tumors and hematological malignancies. However, the efficacy of natural killer(NK) cells, which are an important subset of innate lymphocytes used in anticancer immunotherapy, remains limited. Hypoxia, a critical characteristic of the tumor microenvironment(TME), is involved in tumor development and resistance to radiotherapy, chemotherapy, and immunotherapy. Moreover, hypoxia contributes to the impairment of NK cell function and may be a significant factor that limits their therapeutic effects. Targeted hypoxia therapy has emerged as a promising research area for enhancing the efficacy of NK cell therapy. Therefore, understanding how the hypoxic TME influences NK cell function is crucial for improving antitumor treatment outcomes.

关键词： Hypoxia immunotherapy NK cell tumor microenvironment

Double-branch forgery image detection based on multi-scale feature fusion

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Optoelectronics Letters 2024年第5期20卷 307-312页

作者： zhang Hongying guo Chunxing WANG Xuyong College of Electronic Information and Automation Civil Aviation University of ChinaTianjin 300300China

Most of existing methods exhibit poor performance in detecting forged images due to the small size of tampered areas and the limited pixel difference between untampered and tampered regions. To alleviate the above problem, a double-branch tampered image detection based on multi-scale features is proposed. Firstly, we introduce a fusion module based on attention mechanism in the first branch to enhance the network's sensitivity towards tampered regions. Secondly, we construct a second branch specifically designed for detection, aiming to identify subtle differences between tampered and untampered areas by utilizing rich edge information from shallow features as guidance. Compared to the existing methods on the public benchmark datasets CASIA1.0, Columbia and NIST16, the values of F-score reached 0.766, 0.900 and 0.930 on those datasets, respectively. The experimental results show that our method could significantly improve the accuracy on detecting the tampered area.

关键词： branch image utilizing

Numerical Simulation of the Seismic Response of a Horizontal Storage Tank Based on a SPH-FEM Coupling Method

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1655-1678页

作者： Peilei Yan Endong guo HouliWu Liangchao zhang Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin150080China

A coupled numerical calculation method combining smooth particle hydrodynamics(SPH)and the finite element method(FEM)was implemented to investigate the seismic response of horizontal storage *** of a horizontal storage tank featuring a free liquid surface under seismic action was constructed using the SPH–FEM coupling *** stored liquid was discretized using SPH particles,while the tank and supports were discretized using the *** interaction between the stored liquid and the tank was simulated by using the meshless particle contact ***,the numerical simulation results were compared and analyzed against seismic simulation shaking table test data to validate the ***,a series of numerical models,considering different liquid storage volumes and seismic effects,were constructed to obtain time history data of base shear and top center displacement,which revealed the seismic performance of horizontal storage *** simulation results and experimental data showed good agreement,with an error rate of less than 18.85%.And this conformity signifies the rationality of the SPH-FEM coupling *** base shear and top center displacement values obtained by the coupled SPH-FEM method were only 53.3% to 69.1% of those calculated by the equivalent mass method employed in the current *** the stored liquid volume increased,the seismic response of the horizontal storage tank exhibited a gradual upward trend,with the seismic response increasing from 73% to 388% for every 35% increase in stored liquid *** maximum von Mises stress of the tank and the supports remained below the steel yield strength during the *** coupled SPH-FEM method holds certain advantages in studying the seismic problems of tanks with complex structural forms,particularly due to the representation of the flow field distribution during earthquakes by involving reservoir fluid participation.

关键词： SPH-FEM coupling method horizontal storage tank seismic response sloshing

Degradation of neonicotinoids with different molecular structures in heterogeneous peroxymonosulfate activation system through different oxidation pathways

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Chinese Chemical Letters 2024年第9期35卷 331-339页

作者： Ruonan guo Heng zhang Changsheng guo Ningqing Lv Beidou Xi Jian Xu State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China

The elimination of neonicotinoids(NEOs)from water has been a research priority due to their threats to human health and *** this study,we established the heterogeneous peroxymonosulfate(PMS)activation system using manganese catalyst(Mn NC)and cobalt catalyst(Co NC)to trigger the nonradical oxidation and synergistic oxidation pathway,respectively to remove *** results showed that the nonradical oxidation system exhibited superior NEOs degradation *** composition of organic pollutants in wastewater significantly impacted subsequent degradation *** charge distribution and reaction sites of various NEOs were analyzed using density functional theory(DFT)calculations,and it demonstrated the electron distribution and activity of NEOs were significantly influenced by the type and number of *** group(–NO_(2))and cyanide group(–C≡N)were identified as strong electron-withdrawing groups and prone to be attacked by negatively charged *** transformation of NEOs was analyzed,and result showed that the C and N sites adjacent to the nitro group and cyanide group were more susceptible to oxidation attacks.S and N atoms,which possess strong electronegativity and high electron cloud density,were identified as key active sites in the degradation *** outcomes of this study provide valuable guidance for the oriented regulation of oxidation pathways towards efficient removal of NEOs in water.

关键词： Fenton-like processes Molecular structure Neonicotinoids Nonradical oxidation Degradation pathway

Preface:special topic on rechargeable battery technology

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Science China Chemistry 2024年第1期67卷 1-3页

作者： Yu-guo guo Qiang zhang Jun Chen Li-Jun Wan CAS Key Laboratory of Molecular Nanostructure and Nanotechnology CAS Research/Education Center for Excellence in Molecular SciencesBeijing National Laboratory for Molecular Sciences(BNLMS)Institute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Frontiers Science Center for New Organic Matter Renewable Energy Conversion and Storage Center(RECAST)Haihe Laboratory of Sustainable Chemical TransformationsKey Laboratory of Advanced Energy Materials Chemistry(Ministry of Education)College of ChemistryNankai UniversityTianjin 300071China

Rechargeable batteries play a major role in the transition from fossil energy to renewable energy and are considered the key-enabling decarbonization technology for several industries,including electronics,transportat... 详细信息

关键词： battery artificial technology