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Acta Mathematicae Applicatae Sinica 2024年

作者： Ke GUO wan-biao MA School of Mathematics and Physics University of Science and Technology Beijing

Kawasaki disease（KD） is an acute, febrile, systemic vasculitis that mainly affects children under five years of age. In this paper, we propose and study a class of 5-dimensional ordinary differential equation model describing the vascular endothelial cell injury in the lesion area of KD. This model exhibits forward/backward bifurcation. It is shown that the vascular injury-free equilibrium is locally asymptotically stable if the basic reproduction number r0rther, we obtain two types of sufficient conditions for the global asymptotic stability of the vascular injury-free equilibrium, which can be applied to both the forward and backward bifurcation cases. In addition, the local and global asymptotic stability of the vascular injury equilibria and the presence of Hopf bifurcation are studied. It is also shown that the model is permanent if the basic reproduction number r0> 1, and some explicit analytic expressions of ultimate lower bounds of the solutions of the model are *** results suggest that the control of vascular injury in the lesion area of KD is not only correlated with the basic reproduction number r0, but also with the growth rate of normal vascular endothelial cells promoted by the vascular endothelial growth factor.

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A columnar multi-layer sliding triboelectric nanogenerator for water wave energy harvesting independent of wave height and direction

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Nano research 2024年第4期17卷 3029-3034页

作者： Xue Miao Hanxiao Yang Zekun Li Meifei Cheng Yilin Zhao Lingyu wan Aifang Yu Junyi Zhai Center on NanoEnergy research School of Physical Science and TechnologyGuangxi UniversityNanning 530004China Beijing Institute of Nano Energy and Nano Systems Chinese Academy of SciencesBeijing 101400China School of Nanoscience and Engineering University of Chinese Academy of ScienceBeijing 101408China

The ocean,with its highly variable and complex meteorological conditions,harbors enormous renewable *** nanogenerators(TENGs),which possess unique advantages,show exciting prospects in water wave energy *** to design and optimize TENGs to cover all characteristic water wave energies and achieve efficient energy utilization is *** this paper,we carefully designed and fabricated a columnar multi-layer sliding TENG(CMLS-TENG)that can harvest water wave energy independent of wave height and *** rods with a hollow acrylic spherical shell were introduced to deliver wave energy,ensuring that the CMLS-TENG can work in all directions from 0°to 360°.Based on the sliding structure,switching the optimized CMLS-TENG is independent of wave *** optimized CMLS-TENG can achieve a total power density of 730 mW/m^(3) at a wave height of only 4.8 cm regardless of wave direction,which can illuminate multiple light-emitting diodes(LEDs)to provide lighting and provide power to a watch and a hygrometer for temperature and humidity *** work provides new choices and hopes for the effective collection of full-range water wave energy.

关键词： triboelectric nanogenerator wave energy multi-direction columnar slide

Achieving Synergistic Improvement in Dielectric and Energy Storage Properties of All-Organic Poly(Methyl Methacrylate)-Based Copolymers Via Establishing Charge Traps

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Energy & Environmental Materials 2024年第2期7卷 308-319页

作者： Guanghu He Huang Luo Chuanfang Yan Yuting wan Dang Wu Hang Luo Yuan Liu Sheng Chen Key Laboratory of Polymeric Materials and Application Technology of Hunan Province College of ChemistryXiangtan UniversityXiangtan 411105China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Guangdong University of Petrochemical Technology Maoming 525000China

How to achieve synergistic improvement of permittivity(ε_(r))and breakdown strength(E_(b))is a huge challenge for polymer ***,for the first time,theπ-conjugated comonomer(MHT)can simultaneously promote theε_(r)and E_(b)of linear poly(methyl methacrylate)(PMMA)*** PMMA-based random copolymer films(P(MMA-co-MHT)),block copolymer films(PMMA-b-PMHT),and PMMA-based blend films were prepared to investigate the effects of sequential structure,phase separation structure,and modification method on dielectric and energy storage properties of PMMA-based dielectric *** a result,the random copolymer P(MMA-coMHT)can achieve a maximumε_(r)of 5.8 at 1 kHz owing to the enhanced orientation polarization and electron *** electron injection and charge transfer are limited by the strong electrostatic attraction ofπ-conjugated benzophenanthrene group analyzed by the density functional theory(DFT),the discharge energy density value of P(MMA-co-PMHT)containing 1 mol%MHT units with the efficiency of 80%reaches15.00 J cm^(-3)at 872 MV m^(-1),which is 165%higher than that of pure *** study provides a simple and effective way to fabricate the high performance of polymer dielectrics via copolymerization with the monomer of P-type semi-conductive polymer.

关键词： dielectric capacitor electrical properties energy density polymer dielectric semiconductor polymer

Boosting thermal stability and crystallization of closed-loop-recyclable biodegradable poly(p-dioxanone) by end-group regulation

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Science China Chemistry 2024年第2期67卷 642-651页

作者： Jin Lei Zhu-Xin Gui wan-Ting Xiong Gang Wu Si-Chong Chen Yu-Zhong wang The Collaborative Innovation Center for Eco-Friendly and Fire-Safety Polymeric Materials(MoE) National Engineering Laboratory of Eco-Friendly Polymeric Materials(Sichuan)State Key Laboratory of Polymer Materials EngineeringCollege of ChemistrySichuan UniversityChengdu610064China

A chemically closed-loop-recyclable biodegradable polymer,poly(p-dioxanone)(PPDO),is one of the ideal candidates for single-use plastic products due to its suitability for different application ***,when PPDO wastes can be collected,its monomer p-dioxanone(PDO) will be obtained through chemical recycling of these wastes;when cannot be collected,the wastes are able to be biodegraded into harmless ***,unsatisfied thermal stability and low crystallization rate of PPDO restrict its wider ***,based on end-group regulation,we simultaneously realized the significant enhancement of thermal stability and crystallization of PPDO through the simple melt processing with tributyl phosphite(TBP) or triphenyl phosphite(TPP).The model reactions were conducted to investigate the reaction mechanism and theoretical products during the preparation of PPDO/phosphite *** kinds of phosphites were proved to act as the end-capped reagent and chain extender in the melt processing,while TBP presented better *** a result,the activation energy of thermal decomposition was largely elevated,and the unprecedented T_(5%)(the temperature at a weight loss of 5%) and Tmax(the temperature at a maximum rate of weight loss) of PPDO were obtained,i.e.,T_(5%)of ~330 ℃ and Tmaxof ~385 ℃ in N_(2) atmosphere,T_(5%)of ~240 ℃ and Tmaxof ~317 ℃ in air atmosphere,***,the increased crystallization rate,crystallinity,crystalline orderliness,and realizable monomer recovery(yield >90%,purity >99.9%) of PPDO/phosphite compounds were confirmed.

关键词： poly(p-dioxanone) phosphite thermal stability crystallization end-group regulation

Evolution of interfacial heat transfer,contact behavior and microstructure during sub-rapid solidification of molten steel with different hydrogen contents

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Journal of Iron and Steel research International 2024年第1期31卷 215-223页

作者： Cheng Lu wan-lin wang Chen-yang Zhu Jie Zeng Xin-yuan Liu Hua-long Li School of Metallurgy and Environment Central South UniversityChangsha410083HunanChina National Center for International research of Clean Metallurgy Central South UniversityChangsha410083HunanChina Institute of research of Iron and Steel ShasteelZhangjiagang215625JiangsuChina

Typical q235 low-carbon steel samples with different hydrogen contents(0.0004,0.0008,and 0.0013 wt.%)were prepared by adjusting the environment humidity and *** effects of hydrogen on interfacial heat transfer,contact behavior,and microstructure evolution were investigated using a novel droplet solidification *** results revealed that when the hydrogen content increases from 0.0004 to 0.0013 wt.%,the maximum heat flux between the molten steel and cooling substrate decreases from 8.01 to 6.19 MW/m^(2),and the total heat removed in the initial 2 s reduces from 10.30 to 8.27 MJ/m^(2).Moreover,the final contact angle between the molten steel and substrate increases from 103.741°to 113.697°,and the number of pores on the droplet bottom surface increases significantly from 21 to 210 with the increase in *** surface roughness of the droplet bottom surface increases from 20.902 to 49.181 *** addition,the average grain size of the droplet increases from 14.778 to 33.548 pm with the increase in the hydrogen *** interfacial contact condition becomes worse due to the escape of hydrogen from the steel matrix during the cooling process,which leads to the reduction in the interfacial heat transfer and the increase in the grain size.

关键词： Strip casting Hydrogen content Interfacial heat transfer behavior Contact behavior Microstructure evolution

More tree growth reduction due to consecutive drought and its legacy effect for a semiarid larch plantation in Northwest China

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Journal of Forestry research 2024年第2期35卷 188-196页

作者： Yanfang wan Pengtao Yu Yanhui wang Jiamei Li Yushi Bai Yipeng Yu Bingbing Liu Xiaocha Wei Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration Ecology and Nature Conservation InstituteChinese Academy of ForestryBeijing 100091People’s Republic of China

Extreme climate has increasingly led to negative impacts on forest ecosystems globally,especially in semiarid areas where forest ecosystems are more ***,it is poorly understood how tree growth is affected by different drought *** 2006–2009,the larch plantations in the semiarid areas of Northwest China were negatively affected by four consecutive dry years,which was a very rare phenomenon that may occur frequently under future climate *** this study,we analyzed the effect of these consecutive dry years on tree growth based on the data of the tree rings in the dominant layer of the forest canopy on a larch *** found that the tree-ring width index(rWI)in dry years was lower than that in normal years,and it experienced a rapidly decreasing trend from 2006 to 2009(slope=-0.139 year^(-1),r=-0.94)due to water supply deficits in those dry *** induced legacy effects of tree growth reduction,and consecutive dry years corresponded with greater growth reductions and legacy *** reductions and legacy effects were significantly stronger in the third and fourth consecutive dry years than that of single dry year(press caused by consecutive dry *** results showed that larch trees experienced greater tree growth reduction due to consecutive dry years and their legacy effect,and the trees had lower recovery rates after consecutive dry *** results highlight that consecutive dry years pose a new threat to plantations under climate warming,and thus,the effect of climate extremes on tree growth should be considered in growth models in semiarid areas.

关键词： Tree rings Drought effects Legacy effects Growth-climate relationships Larix principis-rupprechtii

Feasibility of using Vis-NIr spectroscopy and PXrF spectrometry to estimate regional soil cadmium concentration

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Journal of Environmental Sciences 2024年第11期145卷 88-96页

作者： Mengxue wan Fan Ya’nan Wentao Jiao Wenyou Hu Mingchao Lyu Weidong Li Chuanrong Zhang Biao Huang Key Laboratory of Soil Environment and Pollution remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Department of Environmental Science Zhejiang UniversityHangzhou 310058China Guangdong Provincial Academy of Environmental Science Guangzhou 510045China Department of Geography University of ConnecticutStorrsCT 06269USA

Conventionally,soil cadmium(Cd)measurements in the laboratory are expensive and timeconsuming,involving complex processes of sample preparation and chemical *** study aimed to identify the feasibility of using sensor data of visible near-infrared reflectance(Vis-NIr)spectroscopy and portable X-ray fluorescence spectrometry(PXrF)to estimate regional soil Cd concentration in a time-and *** sensor data of Vis-NIr and PXrF,and Cd concentrations of 128 surface soils from Yunnan Province,China,were ***-product analysis(OPA)was used for synthesizing the sensor data and Granger-ramanathan averaging(GrA)was applied to fuse the model *** neural network(ANN)models were built using Vis-NIr data,PXrF data,and OPA data,*** showed that:(1)ANN model based on PXrF data performed better than that based on Vis-NIr data for soil Cd estimation;(2)Fusion methods of both OPA and GrA had higher predictive power(r^(2))=0.89,ratios of performance to interquartile range(rPIq)=4.14,and lower root mean squared error(rMSE)=0.06,in ANN model based on OPA fusion;r^(2)=0.88,rMSE=0.06,and rPIq=3.53 in GrA model)than those based on either Vis-NIr data or PXrF *** conclusion,there exists a great potential for the combination of OPA fusion and ANN to estimate soil Cd concentration rapidly and accurately.

关键词： Artificial neural network Outer-product analysis Granger-ramanathan averaging Soil Cd concentration Fusion method

Metal–ligand interfaces for well-defined gold nanoclusters

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Science China Chemistry 2024年第3期67卷 806-823页

作者： Dan Yang Yating Wu Zhaotong Yuan Chunmei Zhou Yihu Dai Xiaoyue wan Yan Zhu Yanhui Yang Institute of Advanced Synthesis School of Chemistry and Molecular EngineeringNanjing Tech UniversityNanjing 211816China School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093China College of Material and Chemical Engineering Minjiang UniversityFuzhou 350108China

Ligand engineering for well-defined gold nanoclusters(Au NCs) is getting more extensive attention. Organizing the Au-ligand interfaces on gold NCs can achieve the structural and functional control. This review focuses on the Au-ligand interfaces including gold-phosphorus(Au-P), gold-sulfur(Au-S), gold-selenium(Au-Se), gold-carbon(Au-C), and gold-nitrogen(Au-N), derived from the bonding between Au atoms and the different ligands(e.g., organic phosphine, thiolate, selenolate, alkynyl,n-heterocyclic carbene and nitrogenous ligands). The formation mechanism of Au-ligand interfaces is well discussed. In addition, the effects of Au-ligand interfaces on the stability, optical property, and catalysis are also presented. We hope the advances in this research area can boost the development of Au NC sciences.

关键词： Au nanoclusters well-defined structures metal–ligand interfaces formation mechanism structure–property correlation

Detection of a mud volcano in the Weitan Banks area of the northern South China Sea

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Journal of Oceanology and Limnology 2024年第5期42卷 1450-1469页

作者： Wei LUO Pin YAN Yanlin wanG Junhui YU qionghua wan Zhenbo ZHANG Tao XUE Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China CNOOC International Energy Services(Beijing)Co. Ltd.Beijing 100028China University of Chinese Academy of Sciences Beijing 100049China Oilfield Engineering research Institute of Geophysics CNOOC Energy Technology and ServicesZhanjiang 524057China

Situated between the petroliferous Cenozoic Zhujiang(Pearl)river Mouth Basin and the mud volcano-rich Mesozoic Dongsha Basin in the middle sector of the northern South China Sea,the Weitan Banks area has been previously mapped as a basement high that is composed of Mesozoic magmatic *** this study,we present several favorable indicators for petroleum geology that were detected from geophysical profiling and benthic sampling in the area.A conspicuous hill was discovered,named“Zhongwei Hill”,~80 m high above the~340 m deep seafloor and~1 km broad,in a depression with more than 7 km thick sedimentary *** Zhongwei Hill was seismically imaged with a mushroom-shaped structure and containing a cake-like crown,fluid flow pipes,and an~10 km broad anticline at ***,the hill represents a source-plumbing-eruption *** gas zones linked to deep fracture were found at or near the *** correlation indicates that the deep strata comprise the Jurassic and Paleogene strata,the major hosts of hydrocarbon source *** addition to the hill,there are number of mounds from which three bottom water samples were collected and the samples are rich in dissolved methane with concentrations high up to~900 nmol/L,much higher than the background level(0.5–2 nmol/L).The benthic samples are rich in coarse sediment clastics,authigenic carbonate nodules,and deep-water habitats likely feeding on methanotrophic *** these observations and the context,we propose that the Zhongwei Hill represents a mud volcano,likely thermally driven,that seeps methane from Jurassic and Paleogene source layers,thus poses a favorable clue for significant hydrocarbon generation capacity in transitional zone of the Zhujiang river Mouth Basin and the Dongsha Basin.

关键词： South China Sea Zhongwei Hill deep-level anticline mud volcano Mesozoic source layer hydrocarbon generation

Generation of polarized electron beams through self-injection in the interaction of a laser with a pre-polarized plasma

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High Power Laser Science and Engineering 2024年第3期12卷 62-68页

作者： L.r.Yin X.F.Li Y.J.Gu N.Cao q.Kong M.Büscher S.M.Weng M.Chen Z.M.Sheng Key Laboratory of Nuclear Physics and Ion-beam Application(MoE) Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan UniversityShanghaiChina State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina SANKEN(Institute of Scientific and Industrial research) Osaka UniversityOsakaJapan Sichuan research Institute Shanghai Jiao Tong UniversityChengduChina Peter Grünberg Institut(PGI-6) Forschungszentrum JülichJülichGermany Institut für Laser-und Plasmaphysik Heinrich-Heine-Universität DüsseldorfDüsseldorfGermany Key Laboratory for Laser Plasmas(MoE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghaiChina Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghaiChina

Polarized electron beam production via laser wakefield acceleration in pre-polarized plasma is investigated by particlein-cell *** evolution of the electron beam polarization is studied based on the Thomas±Bargmann±Michel±Telegdi equation for the transverse and longitudinal self-injection,and the depolarization process is found to be influenced by the injection *** the case of transverse self-injection,as found typically in the bubble regime,the spin precession of the accelerated electrons is mainly influenced by the ***,in the case of longitudinal injection in the quasi-1D regime(for example,*** et al.,***.110,135002(2013)),the direction of electron spin oscillates in the laser *** the electrons move around the laser axis,the net influence of the laser field is nearly zero and the contribution of the wakefield can be ***,an ultra-short electron beam with polarization of 99%can be obtained using longitudinal self-injection.

关键词： laser wakefield acceleration longitudinal self-injection particle-in-cell simulation polarized electron beam