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Effect of solvent on the initiation mechanism of living anionic polymerization of styrene:A computational study

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Chinese Journal of Chemical Engineering 2024年第5期69卷 135-142页

作者： Shen Li Yin-ning Zhou Zhong-Xin Liu Zheng-hong Luo School of Chemical Engineering and Technology Hainan UniversityHaikou 570228China Department of Chemical Engineering School of Chemistry and Chemical EngineeringState Key Laboratory of Metal Matrix CompositesShanghai Jiao Tong UniversityShanghai 200240China

For living anionic polymerization(LAP),solvent has a great influence on both reaction mechanism and kinetics.In this work,by using the classical butyl lithium-styrene polymerization as a model system,the effect of solvent on the mechanism and kinetics of LAP was revealed through a strategy combining density functional theory(DFT)calculations and kinetic modeling.In terms of mechanism,it is found that the stronger the solvent polarity,the more electrons transfer from initiator to solvent through detailed energy decomposition analysis of electrostatic interactions between initiator and solvent molecules.Furthermore,we also found that the stronger the solvent polarity,the higher the monomer initiation energy barrier and the smaller the initiation rate coefficient.Counterintuitively,initiation is more favorable at lower temperatures based on the calculated results ofΔG_(TS).Finally,the kinetic characteristics in different solvents were further examined by kinetic modeling.It is found that in benzene and n-pentane,the polymerization rate exhibits first-order kinetics.While,slow initiation and fast propagation were observed in tetrahydrofuran(THF)due to the slow free ion formation rate,leading to a deviation from first-order kinetics.

关键词： Living anionic polymerization Solvent effect Reaction kinetics Computational chemistry Mathematical modeling Kinetic modeling

Ballistic performance of spherical fragments penetrating PCrNi3MoV target plates

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Defence Technology（防务技术） 2024年第3期33卷 295-307页

作者： Dou hong Wenbin Li Yu Zheng Yiming Li ning Jiang Kebin Zhang Ministerial Key Laboratory of ZNDY Nanjing University of Science and TechnologyNanjingChina

PCrNi3MoV steel is a medium-carbon,low-alloy quenched and tempered steel that finds its applications in military gun barrels due to the high wear resistance and ablation resistance.To study the penetration and failure modes of PCrNi3MoV plates impacted by tungsten spheres,tungsten spheres of various diameters(5 mm,8 mm,and 10 mm)were used to impact PCrNi3MoV steel plates with thicknesses of 6 mm,9 mm,and 14 mm.The penetration performance of the spheres was analyzed for different velocities,and the ultimate penetration velocity of the plate was obtained.It was found that the primary failure modes of the PCrNi3MoV plate were compression pitting failure and shear failure.Using the dimensional analysis method,a relationship between the bulge height of the steel plate and the fragment velocity,an equation for the ultimate penetration velocity,and a relationship between the target penetration energy and the fragment velocity were obtained.Then,a projectile-target action index was proposed to describe the process of tungsten spheres with different velocities impacting target plates.The results suggested that under the same thickness of the target plate,a larger-diameter fragment required more kinetic energy to obtain the same ultimate penetration effect as a smaller-diameter fragment.The equations obtained through dimensional analysis predicted values that agreed well with experimental values,indicating that these equations can be applied to engineering applications.

关键词： Impact damage Ultimate penetration velocity Bulge height Target penetration energy Failure modes

Treatment of hemolymphangioma by robotic surgery: A case report

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 596-600页

作者： Tian-ning Li Yan-hong Liu Jia Zhao hong Mu Lei Cao Department of Clinical Lab Tianjin First Central HospitalTianjin 300000China Nankai University Tianjin Union Medical CenterTianjin 300000China Tianjin Medical University Tianjin First Center HospitalTianjin 300000China

BACKGROUND Hemolymphangioma of the jejunum is rare and lacks clinical specificity,and can manifest as gastrointestinal bleeding,abdominal pain,and intestinal obstruction.Computed tomography,magnetic resonance imaging,and other examinations show certain characteristics of the disease,but lack accuracy.Although capsule endoscopy and enteroscopy make up for this deficiency,the diagnosis also still re-quires pathology.CASE SUMMARY A male patient was admitted to the hospital due to abdominal distension and abdominal pain,but a specific diagnosis by computed tomography examination was not obtained.Partial resection of the small intestine was performed by robotic surgery,and postoperative pathological biopsy confirmed the diagnosis of hemo-lymphangioma.No recurrence in the follow-up examination was observed.CONCLUSION Robotic surgery is an effective way to treat hemolymphangioma through minima-lly invasive techniques under the concept of rapid rehabilitation.

关键词： Hemolymphangioma Enteroscopy Robotic surgery Rehabilitation Case report

Multiplicity of solutions for the semilinear subelliptic Dirichlet problem

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Science China Mathematics 2024年第3期67卷 475-504页

作者： Hua Chen hong-Ge Chen Jin-ning Li Xin Liao School of Mathematics and Statistics Wuhan UniversityWuhan 430072China Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China

In this paper,we study the semilinear subelliptic equation{−△Xu=f(x,u)+g(x,u)inΩ,u=0 on∂Ω,where△X=−∑m i=1 Xi∗Xi is the self-adjoint Hormander operator associated with the vector fields X=(X_(1),X_(2),...,X_(m))satisfying the Hormander's condition,f(x,u)∈C(Ω×R),g(x,u)is a Carathéodory function onΩ×R,andΩis an open bounded domain in R~n with smooth boundary.Combining the perturbation from the symmetry method with the approaches involving the eigenvalue estimate and the Morse index in estimating the minimax values,we obtain two kinds of existence results for multiple weak solutions to the problem above.Furthermore,we discuss the difference between the eigenvalue estimate approach and the Morse index approach in degenerate situations.Compared with the classical elliptic cases,both approaches here have their own strengths in the degenerate cases.This new phenomenon implies that the results in general degenerate cases would be quite different from the situations in classical elliptic cases.

关键词： degenerate elliptic equations Hormander operators perturbation method Morse index

A stable one-point quadrature rule for three-dimensional numerical manifold method

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Science China(Technological Sciences) 2024年第5期67卷 1401-1416页

作者： ZHANG ning ZHENG hong YANG Liang WU WenAn YUAN Chi School of Civil Engineering Qinghai UniversityQinghai810016China Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing100124China Faculty of Engineering China University of GeoscienceWuhan430074China

We present a numerically stable one-point quadrature rule for the stiffness matrix and mass matrix of the three-dimensional numerical manifold method(3D NMM).The rule simplifies the integration over irregularly shaped manifold elements and overcomes locking issues,and it does not cause spurious modes in modal analysis.The essential idea is to transfer the integral over a manifold element to a few moments to the element center,thereby deriving a one-point integration rule by the moments and making modifications to avoid locking issues.For the stiffness matrix,after the virtual work is decomposed into moments,higher-order moments are modified to overcome locking issues in nearly incompressible and bending-dominated conditions.For the mass matrix,the consistent and lumped types are derived by moments.In particular,the lumped type has the clear advantage of simplicity.The proposed method is naturally suitable for 3D NMM meshes automatically generated from a regular grid.Numerical tests justify the accuracy improvements and the stability of the proposed procedure.

关键词： three-dimensional numerical manifold method quadrature rule locking mass lumping

Identification of overlay differentially expressed genes in both rats and goats with blast lung injury through comparative transcriptomics

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Chinese Journal of Traumatology 2024年第1期27卷 34-41页

作者： hong Wang Jun-hong Gao Xiao-Lin Fan Qing Lu Liang Li ning Ma Qi Wang Yu-Hao Zhang Xi'an Key Laboratory of Toxicology and Biological Effects Research Center for Toxicological and Biological EffectsInstitute for Hygiene of Ordnance IndustryXi'an710065China

Purpose:To identify the potential target genes of blast lung injury(BLI)for the diagnosis and treatment.Methods:This is an experimental study.The BLI models in rats and goats were established by conducting a fuel-air explosive power test in an unobstructed environment,which was subsequently validated through hematoxylin-eosin staining.Transcriptome sequencing was performed on lung tissues from both goats and rats.Differentially expressed genes were identified using the criteria ofq≤0.05 and|log2 fold change|≥1.Following that,enrichment analyses were conducted for gene ontology and the Kyoto Encyclopedia of Genes and Genomes pathways.The potential target genes were further confirmed through quantitative real-time polymerase chain reaction and enzyme linked immunosorbent assay.Results:Observations through microscopy unveiled the presence of reddish edema fluid,erythrocytes,and instances of focal or patchy bleeding within the alveolar cavity.Transcriptome sequencing analysis identified a total of 83 differentially expressed genes in both rats and goats.Notably,49 genes exhibited a consistent expression pattern,with 38 genes displaying up-regulation and 11 genes demonstrating down-regulation.Enrichment analysis highlighted the potential involvement of the interleukin-17 signaling pathway and vascular smooth muscle contraction pathway in the underlying mechanism of BLI.Furthermore,the experimental findings in both goats and rats demonstrated a strong association between BLI and several key genes,including anterior gradient 2,ankyrin repeat domain 65,bactericidal/permeability-increasing fold containing family A member 1,bactericidal/permeability-increasing fold containing family B member 1,and keratin 4,which exhibited up-regulation.Conclusions:Anterior gradient 2,ankyrin repeat domain 65,bactericidal/permeability-increasing fold containing family A member 1,bactericidal/permeability-increasing fold containing family B member 1,and keratin 4 hold potential as target genes for the prognosis,diagnosis,and treatment of BL

关键词： Blast lung injury Transcriptomic Target genes Differentially expressed genes

Design,synthesis,and biological evaluation of novel chrysin derivatives as poly(ADP-ribose)polymerase 1(PARP1)inhibitors for the treatment of breast cancer

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Chinese Journal of Natural Medicines 2024年第5期22卷 455-465页

作者： YANG Yao TONG Jing XIE Xianshun CAO hong FU Yong LUO Yong LIU Shan CHEN Wen YANG ning Hengyang Medical School University of South ChinaHengyang 421200China Emergency Department Hengyang Medical SchoolThe Second Affiliated HospitalUniversity of South ChinaHengyang 421200China Hengyang Medical School The Second Affiliated HospitalUniversity of South ChinaHengyang 421200China Hemato-oncology Department Hengyang Medical SchoolThe Second Affiliated HospitalUniversity of South ChinaHengyang 421200China Department of Breast and Thyroid Surgery Hengyang Medical SchoolThe Second Affiliated HospitalUniversity of South ChinaHengyang 421200China

In this study,we reported the discovery and structure-activity relationship analysis of chrysin derivatives as a new class of inhibitors targeting poly(ADP-ribose)polymerase 1(PARP1).Among these derivatives,compound 5d emerged as the most effective chrysin-based inhibitor of PARP1,with an IC50 value of 108 nmol·L^(-1).This compound significantly inhibited the proliferation and migration of breast cancer cell lines HCC-1937 and MDA-MB-436 by inducing DNA damage.Furthermore,5d induced apoptosis and caused an extended G1/S-phase in these cell lines.Molecular docking studies revealed that 5d possesses a strong binding affinity toward PARP1.In vivo,in a xenograft model,5d effectively reduced tumor growth by downregulating PARP1 expression.Overall,compound 5d shows promise as a potential therapeutic agent for the treatment of BRCA wild-type breast cancer.

关键词： Chrysin derivatives PARP1 Antitumor DNA damage Small molecules

Numerical and experimental study of the effects of wind turbine operation on sand-dust transport characteristics

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 97-113页

作者： Gaosheng Ma hong Han Ye Li Deshun Li Yan Wang ning Fu Quan Zheng Rennian Li School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou 730050China Gansu Provincial Technology Center for Wind Turbines Lanzhou 730050China Key Laboratory of Fluid Machinery and Systems Lanzhou 730050China Multiple Function Towing Tank Laboratory State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Given factors such as reduced land availability for onshore wind farms,wind resource enrichment levels,and costs,there is a growing trend of establishing wind farms in deserts,the Gobi,and other arid regions.Therefore,the relationship between sanddust weather environments and wind turbine operations has garnered significant attention.To investigate the impact of wind turbine wakes on sand-dust transportation,this study employs large eddy simulation to model flow fields,coupled with an actuator line model for simulating rotating blades and a multiphase particle in cell model for simulating sand particles.The research focuses on a horizontal axis wind turbine model and examines the motion and spatiotemporal distribution characteristics of four typical sizes of sand particles in the turbine wake.The findings reveal that sand particles of varying sizes exhibit a spiral settling pattern after traversing the rotating plane of wind turbine blades,influenced by blade shedding vortex and gravity.Sand particles tend to cluster in the peripheries of the vortex cores of low vorticity in the wind turbine wake.The rotation of wind turbines generates a wake vortex structure that causes a significant clustering of sand particles at the tip vortex.As the wake distance increases,the particles that cluster at the turbine's tip gradually spread outward to approximately twice the rotor diameter and then begin to mix with the incoming flow environment.Wind turbines have a noticeable impact on sand-dust transportation,hindering their movement to a significant extent.The average sand-blocking rate exhibits a trend of initially increasing and then decreasing as the wake distance increases.At its peak,the sand-blocking rate reaches an impressive 67.55%.The presence of wind turbines induces the advanced settling of sand particles,resulting in a“triangular”distribution of the deposition within the ground projection area of the wake.

关键词： wind turbine particle transportation actuator line model dry deposition particle clustering

Photocatalytic in situ H2O2 production and activation for enhanced ciprofloxacin degradation over CeO2-Co3O4/g-C3N4:key role of CeO2

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Rare Metals 2024年第6期43卷 2695-2707页

作者： hong-Jie Zhu Yi-Kai Yang Ming-Hui Li Lu-ning Zou Hai-Tao Zhao Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology School of Chemistry and Chemical EngineeringLiaocheng University College of Ecology and Environment Anhui Normal University Liaocheng YiLu Advanced Materials Co. Ltd

The abused ciprofloxacin antibiotics have caused significant environmental damage.Although oxidative degradation of ciprofloxacin exhibits promising efficacy,it often entails excessive energy consumption.Hence,it is necessary to explore an effective and ecologically sustainable degradation strategy.Herein,we demonstrated that g-C3N4decorated with the coordinated CeO2and Co3O4（CeO2-Co3O4/CN） exhibited effective ciprofloxacin photodegradation via in situ H2O2production and activation mechanism.Results indicate that the introduced CeO2enhances the transference of photogenerated electrons to O2by adjusting the oxygen vacancy of photocatalyst,thereby increasing the generation of superoxide radicals,which in turn generate H2O2,resulting in a 22.4-fold increase in H2O2generation over g-C3N4.Moreover,the in situ H2O2generation facilitated by CeO2is confirmed to be essential for ciprofloxacin degradation via CeO2-Co3O4/CN,as it provides enough oxidant for Co3O4to activate into hydroxyl radicals for the pollutants degradation.Ultimately,CeO2-Co3O4/CN achieves a ciprofloxacin degradation ratio of 97.7% within 80 min.This study introduces a novel approach that combines H2O2generation and activation,offering an innovative perspective for achieving clean and efficient purification of antibiotic-contaminated water.

关键词： CeO 2 In situ H 2 O 2 generation Ciprofloxacin degradation Photocatalyst