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Oxidation Resistance of In Situ Reaction/Hot Pressing Synthesized Ti_(2)AlC-20%TiB_(2) Composite at 600-900℃in Air

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 739-748页

作者： Wenting Wang Jingjun Xu Jun zuo Ke Ma Yang li Guangqi He Meishuan li Shengyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China

The oxidation behavior and kinetics of Ti_(2)AlC-20vol.%TiB_(2) composite at 600-900℃ in air were *** results showed that the oxidation kinetics of the composite followed a logarithmic law within the given temperature range,which indicated that the composites had excellent oxidation *** selective oxidation of Al in Ti_(2)AlC was greatly enhanced,which facilitated the formation of a continuous and dense protective layer of Al_(2)O_(3).Meanwhile,the existence of molten B_(2)O_(3) inhibited the outward diffusion of Ti and inward diffusion of oxygen,which prevented the growth of anatase TiO_(2) at 600℃ and rutile TiO_(2) at 700-900℃.Therefore,the incorporation of TiB_(2) completely inhibited the abnormally rapid oxidation of bulk Ti_(2)AlC at 600℃ and improved its oxidation resistance at 700-900℃.

关键词： MAX phase Ti_(2)AlC-TiB_(2)composite Intermediate temperature oxidation Oxidation kinetics

Molecular Chaperone-Dependent Polymer Translocation through Nanopores: The Effects of Chaperone Concentration and Chaperone-Polymer Interaction

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Chinese Journal of Polymer Science 2024年第1期42卷 125-132,I0011页

作者： Chang-Sheng zuo Kang Wang li-Zhen Sun Ting-Ting Sun Department of Physics Zhejiang University of Science and TechnologyHangzhou 310023China Department of Applied Physics Zhejiang University of TechnologyHangzhou 310014China

The polymer translocation through a nanopore from a donor space(or named cis side) to a receiver space(trans side) in the chaperone-induced crowded environment has attracted increasing attention in recent years due to its significance in biological systems and technological applications. In this work, we mainly focus on the effects of chaperone concentration and chaperone-polymer interaction on the polymer translocation. By assuming the polymer translocation to be a quasi-equilibrium process, the free energy F of the polymer can be estimated by Rosenbluth-Rosenbluth method and then the translocation time τ can be calculated by Fokker-Plank equation based on the obtained free energy landscape. Our calculation results show that the translocation time can be controlled by independently tuning the chaperone concentration and chaperone-polymer interaction at the cis side or the trans side. There exists a critical chaperone-polymer attraction ε~*=-0.2 at which the volume exclusion and interaction effects of the chaperone can balance each other. Additionally, we also find that at large chaperone-polymer attraction, the translocation time is mainly governed by the diffusion coefficient of the polymer.

关键词： Polymer translocation Rosenbluth-Rosenbluth method Fokker-Plank equation Free energy landscapes

Fractal model of spontaneous imbibition in low-permeability reservoirs coupled with heterogeneity of pore seepage channels and threshold pressure

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Petroleum Science 2024年第2期21卷 1002-1017页

作者： Ming-Sheng zuo hao Chen Xi-liang liu Hai-Peng liu Yi Wu Xin-Yu Qi National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China College of Safety and Ocean Engineering China University of Petroleum(Beijing)Beijing102249China

Spontaneous imbibition(SI)is an important mechanism for enhancing oil recovery in low-permeability *** to the strong heterogeneity,and the non-Darcy flow,the construction of SI model for lowpermeability reservoirs is extremely ***,traditional SI models based on single or averaged capillary tortuosity ignore the influence of heterogeneity of pore seepage channels and the threshold pressure(TP)on ***,in this work,based on capillary model and fractal theory,a mathematical model of characterizing SI considering heterogeneity of pore seepage channels is *** this basis,the threshold pressure was introduced to determine the pore radius at which the wetted phase can displace *** proposed new SI model was verified by imbibition experimental *** study shows that for weakly heterogeneous cores with permeability of 0-1 m D,the traditional SI model can characterize the imbibition process relatively accurately,and the new imbibition model can increase the coefficient of determination by 1.05 ***,traditional model has serious deviations in predicting the imbibition recovery for cores with permeability of 10-50 m *** new SI model coupling with heterogeneity of pore seepage channels and threshold pressure effectively solves this problem,and the determination coefficient is increased from 0.344 to 0.922,which is increased by2.68 *** low-permeability reservoirs,the production of the oil in transitional pores(0.01-0.1μm)and mesopores(0.1-1μm)significantly affects the imbibition recovery,as the research shows that when the heterogeneity of pore seepage channels is ignored,the oil recovery in transitional pores and mesopores decreases by 7.54%and 4.26%,*** analysis shows that increasing interfacial tension,decreasing contact angle,oil-water viscosity ratio and threshold pressure will increase imbibition *** addition,there are critical values for the influence of these factors o

关键词： Spontaneous imbibition Low-permeability reservoir Fractal model Threshold pressure Capillary tube

Path-Following Control With Obstacle Avoidance of Autonomous Surface Vehicles Subject to Actuator Faults

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IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 956-964页

作者： li-Ying hao Gege Dong Tieshan li Zhouhua Peng the School of Marine Electrical Engineering Dalian Maritime UniversityDalian 116026China the School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731the Navigation CollegeDalian Maritime UniversityDalian 116026 the Yangtze Delta Region Institute(Huzhou) Huzhou 313001China

This paper investigates the path-following control problem with obstacle avoidance of autonomous surface vehicles in the presence of actuator faults,uncertainty and external *** surface vehicles inevitably suffer from actuator faults in complex sea environments,which may cause existing obstacle avoidance strategies to *** reduce the influence of actuator faults,an improved artificial potential function is constructed by introducing the lower bound of actuator efficiency *** nonlinear state observer,which only depends on measurable position information of the autonomous surface vehicle,is used to address uncertainties and external *** using a backstepping technique and adaptive mechanism,a path-following control strategy with obstacle avoidance and fault tolerance is designed which can ensure that the tracking errors converge to a small neighborhood of *** with existing results,the proposed control strategy has the capability of obstacle avoidance and fault tolerance ***,the comparison results through simulations are given to verify the effectiveness of the proposed method.

关键词： Actuator faults autonomous surface vehicle(ASVs) improved artificial potential function nonlinear state observer obstacle avoidance

Saponin Ⅰ from Shuitianqi(Rhizoma Schizocapasae Plantagineae) inhibits metastasis by negatively regulating the transforming growth factor-β1/Smad7 network and epithelial-mesenchymal transition in the intrahepatic metastasis Bagg's Albino/c mouse model

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Journal of Traditional Chinese Medicine 2024年第4期44卷 642-651页

作者： LYU Meixian ZHOU Huan ZHI limin ZHOU Jinling GAN Rizhi QIN Yanping HE Nengting zuo Qiqi li hao DONG Min liANG Gang Pharmaceutical College Guangxi Medical UniversityNanning 530022China Department of Pharmacy Affiliated Tumor Hospital of Guangxi Medical UniversityNanning 530022China Drug clinical trial Facility office the People's Hospital of Guangxi Zhuang Autonomous RegionNanning 530022China College of Pharmacy Guangxi University of Chinese MedicineNanning 530022China Department of Pharmacy the Second Affiliated Hospital of Guangxi Medical UniversityNanning 530005China Department of Pharmacy People's Hospital of Guangxi HezhouHezhou 542899China Department of Pharmacy Guangzhou Women and Children's Medical Center Liuzhou HospitalLiuzhou 545000China Department of Pharmacy First Affiliated Hospital of Gannan Medical UniversityGannan 341000China

OBJECTIVE:To examine the influence of SaponinⅠfrom Shuitianqi(Rhizoma Schizocapasae Plantagineae)(SSPHⅠ)on hepatocellular carcinoma(HCC)metastasis,and to elucidate the underlying ***:The intrahepatic metastasis Bagg's Albino/c(BALB/c)mouse model was established with human hepatocellular carcinomas(HepG2)cells,then treated with normal saline(once per day),cisplatin(2 mg/kg,once every 2 d),and SSPHⅠ(25,50,and 75 mg/kg,once per day).Then,we assessed alterations in the hepatic pathology and target protein expressions in the intrahepatic metastasis BALB/c mouse model using a series of molecular biology ***:Based on our analysis,SSPHⅠsignificantly alleviated hepatocyte necrosis and tumor cells ***,SSPHⅠsuppressed extracellular matrix(ECM)degradation and angiogenesis via a decrease in matrix etalloproteinase-2(MMP-2),MMP-9,CD31,CD34,and vascular endothelial growth factor(VEGF)***,SSPHⅠrepressed invasion and metastasis by suppressing the transforming growth factor-β1(TGF-β1)/Smad7 axis and epithelial-mesenchymal transition(EMT),as evidenced by the scarce TGF-β1,Ncadherin,and Vimentin expressions,and elevated Smad7 and E-cadherin ***:The SSPHⅠ-mediated negative regulation of the TGF-β1/Smad7 axis and EMT are critical for the inhibition of HCC invasion and metastasis.

关键词： carcinoma,hepatocellular epithelial-mesenchymal transition transforming growth factor beta1 Smad7 protein Saponin I from Shuitianqi(Rhizoma Schizocapasae Plantagineae)

Exploring a new path of green and efficient utilization of sinter return fine to produce composite pellets

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Journal of Iron and Steel Research International 2024年第7期31卷 1610-1622页

作者： Yan-biao Chen Wen-guo liu hao Guo Jing-song Wang Qing-guo Xue Hai-bin zuo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China MCC Capital Engineering and Research Incorporation limited Beijing 100176China

Efficient utilization of sinter return fine is an important measure to reduce cost,increase efficiency,save energy and reduce emission.A new path of green and efficient utilization of return fine was proposed to produce composite *** metallurgical properties of composite pellets under the condition of hydrogen-rich blast furnace were *** experimental results indicate that the coated concentrate was consolidated for the composite pellets through normal Fe_(2)O_(3) *** the surface of core return fine,the liquid phase formed due to its low-melting point,assimilated the adjacent concentrate,and then consolidated with the temperature *** with regular pellets,the com-pressive strength and reduction swelling index of composite pellets were decreased,but the reducibility index and softening-melting properties were *** addition,the reduction degradation index of composite pellets was sig-nificantly higher than that of ***,adding composite pellets was conducive to indirect reduction in blast furnace,reducing fuel ratio and improving production *** to the effect of the roasting system on the metallurgical properties,the roasting temperature and time were determined as 1250℃and 30 min,*** composite pellets can be produced under the traditional pelletizing process.

关键词： Sinter Return fine Composite pellet Roasting system Metallurgical property Hydrogen-rich blast furnace

Optimal mining sequence for coal faces under a bedding slope:insight from landslide prevention

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Journal of Mountain Science 2024年第5期21卷 1775-1798页

作者： li Qingmiao Zhao Jianjun li Zhichao DENG Jie zuo Jing LAI Qiyi State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China

Repetitive mining beneath bedding slopes is identified as a critical factor in geomorphic disturbances, especially landslides and surface subsidence. Prior research has largely concentrated on surface deformation in plains due to multi-seam coal mining and the instability of natural bedding slopes, yet the cumulative impact of different mining sequences on bedding slopes has been less explored. This study combines drone surveys and geological data to construct a comprehensive three-dimensional model of bedding slopes. Utilizing FLAC3D and PFC2D models, derived from laboratory experiments, it simulates stress, deformation, and failure dynamics of slopes under various mining sequences. Incorporating fractal dimension analysis, the research evaluates the stability of slopes in relation to different mining sequences. The findings reveal that mining in an upslope direction minimizes disruption to overlying strata. Initiating extraction from lower segments increases tensile-shear stress in coal pillar overburdens, resulting in greater creep deformation towards the downslope than when starting from upper segments, potentially leading to localized landslides and widespread creep deformation in mined-out areas. The downslope upward mining sequence exhibits the least fractal dimensions, indicating minimal disturbance to both strata and surface. While all five mining scenarios maintain good slope stability under normal conditions, recalibrated stability assessments based on fractal dimensions suggest that downslope upward mining offers the highest stability under rainfall, contrasting with the lower stability and potential instability risks of upslope downward mining. These insights are pivotal for mining operations and geological hazard mitigation in multi-seam coal exploitation on bedding slopes.

关键词： Bedding rock landslides Mining-induced deformation Bedding slope stability Underground mining sequences Fractal-based strength reduction method

Switchable Multicomponent Cyclization Reactions to Access Fluoroalkylated Dihydropyrimidines and Pyrimidines under Solvent-Free Conditions

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Chinese Journal of Chemistry 2024年第12期42卷 1394-1398页

作者： Wanqing zuo Zhizhen Zhu Yu Cheng lingling zuo Xiao Geng Zhifang li Lei Wang College of Material Chemistry and Chemical Engineering Key Laboratory of Organosilicon Chemistry and Material TechnologyMinistryof EducationHangzhouNormal UniversityHangzhouZhejiang311121China Advanced Research Institute and School of Pharmaceutical Sciences Taizhou UniversityJiaojiangZhejiang 318000China state Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai200032China

Comprehensive Summary The development of switchable solvent-free multicomponent reactions to build high-value-added products is an important demand for organic ***,we detailed the successful implementation of a switchable strategy for the construction of diverse 4-fluoroalkyl-1,4-dihydropyrimidines and 4-fluoroalkyl-pyrimidines via a solvent/additive-free[3+2+1]annulation,starting from readily available enamines,trifluoroacetaldehyde hydrate or 1-ethoxy-2,2-difluoroethanol and amidines *** reaction conforms to the concept of green synthesis,and provides a new avenue to access valuable fluorinated heterocycles.

关键词： Fluorine chemistry Multicomponent reactions Environmental chemistry Heterocycles Enaminones Amidines

A High Order Accurate Bound-Preserving Compact Finite Difference Scheme for Two-Dimensional Incompressible Flow

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Communications on Applied Mathematics and Computation 2024年第1期6卷 113-141页

作者： hao li Xiangxiong Zhang Department of Mathematics Purdue University150 N.University StreetWest LafayetteIN47907-2067USA

For solving two-dimensional incompressible flow in the vorticity form by the fourth-order compact finite difference scheme and explicit strong stability preserving temporal discretizations,we show that the simple bound-preserving limiter in li et al.(SIAM J Numer Anal 56:3308–3345,2018)can enforce the strict bounds of the vorticity,if the velocity field satisfies a discrete divergence free *** reducing oscillations,a modified TVB limiter adapted from Cockburn and Shu(SIAM J Numer Anal 31:607–627,1994)is constructed without affecting the bound-preserving *** bound-preserving finite difference method can be used for any passive convection equation with a divergence free velocity field.

关键词： Finite difference Monotonicity Bound-preserving Discrete maximum principle Passive convection Incompressible flow Total variation bounded limiter