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The spectrum and stability of travelling pulses in a coupled Fitzhugh-Nagumo equation

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Science China Mathematics 2024年第5期67卷 975-1010页

作者： Qi Qiao Xiang zhang School of Mathematical Sciences Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Scientific and engineering Computing(Ministry of education) and Shanghai Frontier Science Center of Modern Analysis(CMA-Shanghai)Shanghai Jiao Tong UniversityShanghai 200240China

For a coupled slow-fast Fitzhugh-Nagumo(FhN)equation derived from a reaction-diffusionmechanics(RDM)model,holzer et al.(2013)studied the existence and stability of the travelling pulse,which consists of two fast orbit arcs and two slow ones,where one fast segment passes the unique fold point with algebraic decreasing and two slow ones follow normally hyperbolic critical curve *** and zhang(2021)obtained the existence of the travelling pulse,whose two fast orbit arcs both exponentially decrease,and one of the slow orbit arcs could be normally hyperbolic or not at the ***,we characterize both the nonlinear and spectral stability of this travelling pulse.

关键词： coupled Fitzhugh-Nagumo equation singular perturbation travelling pulse spectrum nonlinear stability spectral stability

C^(α)regularity of weak solutions of non-homogeneous ultraparabolic equations with drift terms

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Science China Mathematics 2024年第1期67卷 23-44页

作者： Wendong Wang Liqun zhang School of Mathematical Sciences Dalian University of TechnologyDalian 116024China Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China

We consider a class of non-homogeneous ultraparabolic differential equations with singular drift terms arising from some physical models,and prove that weak solutions are h?lder continuous,which are sharp in some sense and also generalize the well-known De Giorgi-Nash-Moser theory to degenerate parabolic equations satisfying the h?rmander hypoellipticity *** new ingredients are manifested in two aspects:on the one hand,for lower-order terms,we exploit a new Sobolev inequality suitable for the Moser iteration by improving the result of Pascucci and Polidoro(2004);on the other hand,we explore the G-function from an early idea of Kruzhkov(1964)and an approximate weak Poincaréinequality for non-negative weak sub-solutions to prove the h?lder regularity.

关键词： ultraparabolic equations Moser iteration Poincare inequality C^a regularity

enhancing the vertical resolution of lunar penetrating radar data using predictive deconvolution

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earth and Planetary Physics 2024年第4期8卷 570-578页

作者： Chao Li Jinhai zhang CAS engineering Laboratory for Deep Resources equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

The Yutu-2 rover onboard the Chang’e-4 mission performed the first lunar penetrating radar detection on the farside of the *** high-frequency channel presented us with many unprecedented details of the subsurface structures within a depth of approximately 50 ***,it was still difficult to identify finer layers from the cluttered reflections and scattering *** applied deconvolution to improve the vertical resolution of the radar profile by extending the limited bandwidth associated with the emissive radar *** overcome the challenges arising from the mixed-phase wavelets and the problematic amplification of noise,we performed predictive deconvolution to remove the minimum-phase components from the Chang’e-4 dataset,followed by a comprehensive phase rotation to rectify phase anomalies in the radar ***,we implemented irreversible migration filtering to mitigate the noise and diminutive clutter echoes amplified by *** processed data showed evident enhancement of the vertical resolution with a widened bandwidth in the frequency domain and better signal clarity in the time domain,providing us with more undisputed details of subsurface structures near the Chang’e-4 landing site.

关键词： Chang’e-4 lunar penetrating radar data processing predictive deconvolution irreversible migration filtering

IL-13/IL-13RA2 signaling promotes colorectal cancer stem cell tumorigenesis by inducing ubiquitinated degradation of p53

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Genes & Diseases 2024年第1期11卷 495-508页

作者： Baoyu he Jing Liang Qianqian Qin Yuqin zhang Shuo Shi Jinghe Cao Zhixin zhang Qingli Bie Rou Zhao Li Wei Baogui zhang Bin zhang Department of Laboratory Medicine Affiliated Hospital of Jining Medical UniversityJining Medical UniversityJiningShandong 272000China Postdoctoral Mobile Station of Shandong University of Traditional Chinese Medicine JinanShandong 250355China Department of Reproductive Medicine Affiliated Hospital of Jining Medical UniversityJining Medical UniversityJiningShandong 272000China Department of Gastrointestinal Surgery Affiliated Hospital of Jining Medical UniversityJining Medical UniversityJiningShandong 272000China Institute of Forensic Medicine and Laboratory Medicine Jining Medical UniversityJiningShandong 272067China

Cancer stem cells(CSCs)are considered tumor-initiating cells and the main drivers of disease *** these rare cancer cells,however,remains challenging with respect to therapeutic ***,we report the up-regulation of IL-13RA2 expression in colorectal cancer(CRC)tissues and spheroid *** expression of IL-13RA2 was positively correlated with canonical stemness markers in *** further demonstrated that the level of IL-13 was up-regulated in the serum of CRC ***,recombinant IL-13(rIL13)stimulation promoted the sphere formation,proliferation,and migration of CRC cells in vitro and enhanced tumorigenesis in *** phenotype could be reversed by knocking down ***,IL-13 activated autophagy by inducing LC3I/LC3II transformation in CRC-CSCs,which was crucial for the biological functions of *** further demonstrated that IL-13RA2 acted as a modular link of the e3 ligase UBe3C and the substrate p53 protein,enhancing the interaction of UBe3C and p53,thereby inducing the K48-linked ubiquitination of *** conclusion,the IL-13/IL-13RA2 signaling cascade promotes CRC-CSC self-renewal and tumorigenesis by inducing p53 ubiquitination,adding an important layer to the connection between IL-13 and p53,which can be translated into novel targeted therapies.

关键词： Autophagy Colorectal cancer stem cells IL-13/IL-13RA2 signaling p53

Interface-induced polymerization strategy for constructing titanium dioxide embedded carbon porous framework with enhanced chemical immobilization towards lithium polysulfides

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Nano Research 2024年第3期17卷 1473-1481页

作者： Yue Ouyang Xiaoxiao Li Jiexin Zhu Wei Zong Yuhang Dai Xuan Gao Wei zhang Shengyuan Yang Roohollah Bagherzadeh Feili Lai Yue-e Miao Tianxi Liu State Key Laboratory for Modification of Chemical Fibers and Polymer Materials College of Materials Science and EngineeringDonghua University2999 North Renmin RoadShanghai 201620China The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China Advanced Fibrous Materials LAB Institute for Advanced Textile Materials and Technologies(ATMT)School of Advanced Materials and ProcessesAmirkabir University of TechnologyTehran 15914Iran Christopher Ingold Laboratory Department of ChemistryUniversity College London20 Gordon StreetLondon WC1H 0AJUK Department of Chemistry KU LeuvenCelestijnenlaan 200FLeuven 3001Belgium

The shuttle effect induced by soluble lithium polysulfides(LiPSs)is known as one of the crucial issues that limit the practical applications of lithium-sulfur(Li-S)***,a titanium dioxide nanoparticle embedded in nitrogen-doped porous carbon nanofiber(TiO_(2)@NCNF)composite is constructed via an interface-induced polymerization strategy to serve as an ideal sulfur *** the protection of the nanofiber walls,the uniformly dispersed TiO_(2) nanocrystalline can act as capturing centers to constantly immobilize LiPSs towards durable sulfur ***,the mesoporous microstructure in the fibrous framework endows the TiO_(2)@NCNF host with strong physical reservation for sulfur and LiPSs,sufficient pathways for electron/ion transfer,and excellent endurance for volume *** expected,the sulfur-loaded TiO_(2)@NCNF composite electrode presents a fabulous rate performance and long cycle lifespan(capacity fading rate of 0.062%per cycle over 500 cycles)at 2.0 ***,the assembled Li-S batteries harvest superb areal capacity and cycling stability even under high sulfur loading and lean electrolyte conditions.

关键词： interface-induced polymerization electrospun porous nanofibers lithium-sulfur(Li-S)batteries high sulfur loading lithium polysulfides(LiPSs)immobilization

hydrogen storage thermodynamics and kinetics of as-cast Ce-Mg-Ni-based alloy

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Journal of Iron and Steel Research(International) 2024年第3期31卷 752-766页

作者： Yan Qi Xin zhang Jun Li Dong-liang Zhao Shi-hai Guo Yang-huan zhang Department of Functional Material Research Central Iron and Steel Research InstituteBeijing 100081China China Rare earth New Material(Weishan)Co..Ltd. Jining 277600ShandongChina Collaborative Innovation Center of Integrated exploitation of Bayan Obo Multi-Metal Resources Inner Mongolia University of Science and TechnologyBaotou 014010Inner MongoliaChina

The reaction kinetics of alloys based on magnesium are known to be greatly improved by the partial substitution of Mg with rare earths and transition metals,particularly *** enhanced superficial hydrogen dissociation rate,the weakened Mg-h bond and the lower activation energy following element replacement are thought to be related to the better *** experimental alloys Ce5Mg_(95-x)Ni_(x)(x=5,10,15)were smelted by the vacuum induction *** phase transformation and structural evolution of experimental alloys before and after reaction with hydrogen were char-acterized by X-ray diffraction,scanning electron microscopy and transmission electron *** cast specimens contain CeMg_(12),Mg and Mg_(2)Ni phases,and the increase in Ni content results in an obvious growth of Mg_(2)Ni *** isothermal and non-isothermal hydrogenation and dehydrogenation kinetics of the experimental specimens were investi-gated using the Sievert apparatus,differential scanning calorimetry and thermal gravimetric *** activation energy may be calculated using the Arrhenius and Kissinger *** experimental alloys have been shown to have good activation properties,with a reversible hydriding and dehydriding capacities of around 5.0 wt.%in the first *** initial dehydrogenation temperature of Mgh_(2) decreases from 557.5 to 537.7 K with changing Ni content from 5 to 15 at.%.The dehydrogenation activation energy also reduces from 77.09 to 62.96 kJ/mol,which explains the improved hydrogen storage performance caused by Ni *** can be shown that the impact of Ni on the decomposition enthalpy of Mgh_(2) is quite modest,with the absolute enthalpy(Δhr)only decreasing from 78.48 to 76.15 kJ/mol.

关键词： Mg-based alloy Ni content hydrogen storage kinetics Thermodynamic property Activation energy

eco-toxicity and health risk assessment of polycyclic aromatic hydrocarbons in surface sediments of Burullus Lake in egypt

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China Geology 2024年第3期7卷 460-468页

作者： hanan e Osman Mohamed h e el-Morsy hazem T Abd el-hamid Department of Biology Faculty of Applied ScienceUmm Al-Qura UniversityMecca 24382Saudi Arabia Deanship of Scientific Research Umm Al-Qura UniversityMakkah 24372Saudi Arabia National Institute of Oceanography and Fisheries(NIOF) Cairo 11865Egypt Botany and Microbiology Department Faculty of ScienceAl-Azhar UniversityCairo 11651Egypt

Polycyclic aromatic hydrocarbons(PAhs)are ubiquitous environmental contaminants of growing concern due to their potential ecological and human health *** study presents a comprehensive assessment of PAhs contamination in the surface sediments of Burullus Lake,a vital and second largest delta lake in *** aim was to evaluate the eco-toxicity and potential health risks associated with the presence of these *** seven sediment samples were collected from various drains in the southern part of Burullus *** extraction method was employed to extract PAhs(16PAhs)from the sediment ***,target compounds were located using *** results showed that samples contained PAhs levels ranging from 0.038×10^(-6)to 0.459×10^(-6),which is considered heavily polluted by the european standard for PAhs ***,there was no apparent source of PAhs in the elKhashah drain or the Brinbal Canal,as hPLC found none of the *** most prevalent compound in sediment samples along the study area was *** diagnostic indices in the present study indicated that the hydrocarbons in the region originated from pyrolytic and man-made sources along the drains of Burullus *** principal component analysis(PCA)and diagnostic ratios revealed that coal combustion and pyrolytic sources were responsible for the PAhs contamination in the surface *** non-carcinogenic risk(hI),which is the product of the hQs for the adult and child populations,respectively,was *** values under 1,therefore,demonstrated that they had no carcinogenic effects on human *** and MeQs in the sediments of Burullus Lake do not have a cancer-causing impact on *** the safety of nearby wildlife,aquatic life,and people,all activities that raise petroleum hydrocarbon levels in Burullus Lake must be adequately regulated and *** to the ecological risk assessment,there is little chance that PAhs will be found

关键词： Polycyclic aromatic hydrocarbons Diagnostic indices Toxicity Delta lake sediment Burullus Lake human health risk Aquatic ecosystem hPLC Coal combustion

Symmetrization of quasi-regular patterns with periodic tilting of regular polygons

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Computational Visual Media 2024年第3期10卷 559-576页

作者： Zhengzheng Yin Yao Jin Zhijian Fang Yun zhang huaxiong zhang Jiu Zhou Lili he School of Computer Science and Technology Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Provincial Innovation Center of Advanced Textile Technology Shaoxing 312000China School of Media engineering Communication University of ZhejiangHangzhou 310018China

Computer-generated aesthetic patterns arewidely used as design materials in various ﬁelds. Themost common methods use fractals or dynamicalsystems as basic tools to create various patterns. Toenhance aesthetics and controllability, some researchershave introduced symmetric layouts along with thesetools. One popular strategy employs dynamical systemscompatible with symmetries that construct functionswith the desired symmetries. however, these aretypically conﬁned to simple planar symmetries. Theother generates symmetrical patterns under theconstraints of tilings. Although it is slightly moreﬂexible, it is restricted to small ranges of tilingsand lacks textural variations. Thus, we proposed anew approach for generating aesthetic patterns bysymmetrizing quasi-regular patterns using general kuniformtilings. We adopted a uniﬁed strategy toconstruct invariant mappings for k-uniform tilings thatcan eliminate texture seams across the tiling ***, we constructed three types of symmetriesassociated with the patterns: dihedral, rotational, andreﬂection symmetries. The proposed method can beeasily implemented using GPU shaders and is highlyefficient and suitable for complicated tiling with regularpolygons. experiments demonstrated the advantages of our method over state-of-the-art methods in terms ofﬂexibility in controlling the generation of patterns withvarious parameters as well as the diversity of texturesand styles.

关键词： quasi-regular patterns(QRP) k-uniform tilings invariant mappings symmetry aesthetic patterns

hydrogen evolution reaction activity enhancement from active site turnover mechanism

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Journal of energy Chemistry 2024年第5期92卷 629-638页

作者： Jiacheng Wang Tongqing Yang Xiyue Li haiqin zhang Yixue zhang Yan he hongyao Xue College of electromechanical engineering Qingdao University of Science and TechnologyQingdao 266061ShandongChina

Although heteroatom doping is an effective way to improve the catalytic activity of transition metal phosphides(TMPs),the mechanism of activity enhancement needs to be further *** this end,we synthesized a Co-doped Ni_(2)P catalyst as a research model and found that the introduction of heterogeneous Co reconstructed the charge distribution around the P site,which effectively enhanced the hydrogen evolution reaction(heR)activity of the pure Ni_(2)*** on in-situ Raman real-time monitoring technology,we monitored for the first time that Co doping triggered a switch of the active site(from the original Co-active site to the P-active site),which promoted the adsorption of h_(2)O to enhance the heR *** density functional theory(DFT)calculations indicated that the P site of Co-Ni_(2)P expressed the highest activity and the Ni site of pure Ni_(2)P expressed the highest activity,which further confirms the in-situ Raman monitoring *** active site turnover mechanism discovered in this study will undoubtedly provide more rational and targeted ideas for future catalyst design.

关键词： In-situ Raman observation heteroatom doping Activesites turnover hydrogen production