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Communications in Theoretical Physics 2024年第7期76卷 76-84页

作者： Yan-Hong Yao xin-he meng School of Physics and Astronomy Sun Yat-sen University School of Physics Nankai University

The Hubble tension persists as a challenge in cosmology. Even early dark energy（EDE） models,initially considered the most promising for alleviating the Hubble tension, fall short of addressing the issue without exacerbating other tensions, such as the S8tension. Considering that a negative dark matter（DM） equation of state（EoS） parameter is conducive to reduce the value of the σ8parameter, we extend the axion-like EDE model in this paper by replacing the cold dark matter（CDM） with DM characterized by a constant EoS wdm（referred to as WDM hereafter）.We then impose constraints on this axion-like EDE extension model, along with three other models: the axion-like EDE model, ΛWDM, and ΛCDM. These constraints are derived from a comprehensive analysis incorporating data from the Planck 2018 cosmic microwave background, baryon acoustic oscillations, and the Pantheon compilation, as well as a prior on H0（i.e. H0= 73.04 ± 1.04, based on the latest local measurement by Riess et al） and a Gaussianized prior on S8（i.e. S8= 0.766 ± 0.017, determined through the joint analysis of KID1000+BOSS+2dLenS）. We find that although the new model maintains the ability to alleviate the Hubble tension to ～1.4σ, it still exacerbates the S8tension to a level similar to that of the axion-like EDE model.

关键词： early dark energy Hubble tension noncold dark matter S8 tension

Microstructure and mechanical properties of a cast TRIP-assisted multiphase stainless steel

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China Foundry 2024年第3期21卷 221-228页

作者： meng-xin Wang Zi-xiang Wu Jing-yu he Xiang Chen School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

Stainless steels are used in a wide range of complex environments due to their excellent corrosion *** stainless steels can offer an excellent combination of strength,toughness and corrosion resistance due to the coexistence of different *** microstructure and mechanical properties of a novel cast multiphase stainless steel,composed of martensite,ferrite,and austenite,were investigated following appropriate heat treatment processes:solution treatment at 1,050℃ for 0.5 h followed by water quenching to room temperature,and aging treatment at 500℃ for 4 h followed by water quenching to room *** show reversed austenite is formed by diffusion of Ni element during aging process,and the enrichment of Ni atoms directly determines the mechanical stability of *** austenite with a lower Ni content undergoes a martensitic transformation during plastic *** tensile strength of the specimen exceeds 1,100 MPa and the elongation exceeds 24%after solid solution,and further increases to 1,247 MPa and 25%after aging *** enhancement is due to the TRIP effect of austenite and the precipitation of the nanoscale G-phase pinning dislocations in ferrite and martensite.

关键词： multiphase stainless steel mechanical properties TRIP effect reversed austenite G-phase

Model-independent determination on H_0 using the latest cosmic chronometer data

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Science China(Physics,Mechanics & Astronomy) 2017年第11期60卷 1-10页

作者： Deng Wang xin he meng Theoretical Physics Division Chern Institute of Mathematics Nankai University Department of Physics Nankai University

We perform the updated constraints on the Hubble constant H_0 by using the model-independent method, Gaussian *** the latest 30 cosmic chronometer measurements, we obtain H_0= 67.38 ± 4.72 km s^(-1)Mpc^(-1), which is consistent with the Planck 2015 and Riess et al. analysis at 1σ confidence level. Different from the results of Busti et al. by only using 19 H(z) measurements, our reconstruction results of H(z) and the derived values of H_0 are insensitive to the concrete choice of covariance functions of Matern family.

关键词：天文测量数据模型宇宙测定可信度分析协方差函数高斯过程 MPC

Traversable braneworld wormholes supported by astrophysical observations

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Frontiers of physics 2018年第1期13卷 109-118页

作者： Deng Wang xin-he meng Theoretical Physics Division Chern Institute of Mathematics Nankai University Tianjin 300071 China Department of Physics Nankai University Tianjin 300071 China

In this study, we investigate the characteristics and properties of a traversable wormhole constrained by the current astrophysical observations in the framework of modified theories of gravity （MOG）. As a concrete case, we study traversable wormhole space-time configurations in the Dvali-Gabadadze- Porrati （DGP） braneworld scenario, which are supported by the effects of the gravity leakage of extra dimensions. We find that the wormhole space-time structure will open in terms of the 2o confidence level when we utilize the joint constraints supernovae （SNe） Ia ＋ observational Hubble parameter data （OHD）＋ Planck ＋ gravitational wave （GW） and z 〈 0.2874. Furthermore, we obtain several model-independent conclusions, such as （i） the exotic matter threading the wormholes can be divided into four classes during the evolutionary processes of the universe based on various energy conditions; （ii） we can offer a strict restriction to the local wormhole space-time structure by using the current astrophysical observations; and （iii） we can clearly identify a physical gravitational resource for the wormholes supported by astrophysical observations, namely the dark energy components of the universe or equivalent space-time curvature effects from MOG. Moreover, we find that the strong energy condition is always violated at low redshifts.

关键词： braneworld model traversable wormholes astrophysical observations

Construction of core@double-shell structured energetic composites with simultaneously enhanced thermal stability and safety performance

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Defence Technology（防务技术） 2024年第4期34卷 134-142页

作者： Peng Wang Wen Qian Ruolei Zhong Fangfang he xin Li Jie Chen Li meng Yinshuang Sun Guansong he Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China State Key Laboratory of Environment-friendly Energy Materials School of Materials and ChemistrySouthwest University of Science and TechnologyMianyang 621010China

The poor thermal stability and high sensitivity severely hinder the practical application of hexanitrohexaazaisowurtzitane(CL-20).herein,a kind of novel core@double-shell CL-20 based energetic composites were fabricated to address the above *** coordination complexes which consist of natural polyphenol tannic acid(TA) and Fe~Ⅲ were chosen to construct the inner shell,while the graphene sheets were used to build the outer *** resulting CL-20/TA-Fe~Ⅲ/graphene composites exhibited simultaneously improved thermal stability and safety performance with only 1 wt% double-shell content,which should be ascribed to the intense physical encapsulation effect from inner shell combined with the desensitization effect of carbon nano-materials from outer *** phase transition(ε to γ) temperature increased from 173.70 ℃ of pure CL-20 to 191.87℃ of CL-20/TA-Fe~Ⅲ/graphene ***,the characteristic drop height(H_(50)) dramatically increased from 14.7 cm of pure CL-20 to112.8 cm of CL-20/TA-Fe~Ⅲ/graphene composites,indicating much superior safety performance after the construction of the double-shell *** general,this work has provided an effective and versatile strategy to conquer the thermal stability and safety issues of CL-20 and contributes to the future application of high energy density energetic materials.

关键词： CL-20 Double-shell structure Thermal stability Safety performance Tannic acid Graphene sheets

Microstructures and mechanical properties of a commercial Mg-Al-Zn-Mn alloy with various hot-extrusion processes

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Rare Metals 2024年第3期43卷 1329-1336页

作者： he Ma Fan-Zhi meng Qiang Yang Ze-Feng Xie Yuan-Ding Huang xin Qiu State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Materials Science and Engineering Changchun University of Science and TechnologyChangchun130022China MagIC-Magnesium Innovation Center Helmholtz-Zentrum Geesthacht21502GeesthachtGermany Engineering Research Center of Optoelectronic Functional Materials Ministry of EducationChangchun University of Science and TechnologyChangchun130022China

Mg-Al-Zn-Mn(AZ)system alloys have become widely used due to their good castability,excellent formability and outstanding corrosion resistance[1-6].However,their strength is still much lower than that of traditional Mg... 详细信息

关键词： alloys alloy corrosion

Incidence Coloring of Outer-1-planar Graphs

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 840-848页

作者： meng-ke QI xin ZHANG School of Mathematics and Statistics Xidian UniversityXi'an 710071China

A graph is outer-1-planar if it can be drawn in the plane so that all vertices lie on the outer-face and each edge crosses at most one another *** is known that every outer-1-planar graph is a planar *** this paper,we conjecture that every planar graph G has a proper incidence(Δ(G)+2)-coloring and confirm it for outer-1-planar graphs with maximum degree at least 8 or with girth at least ***,we prove that every outer-1-planar graph G has an incidence(Δ(G)+3,2)-coloring,and every outer-1-planar graph G with maximum degree at least 8 or with girth at least 4 has an incidence(Δ(G)+2,2)-coloring.

关键词： incidence coloring outer--planar graph planar graph

Dynamically switchable porphyrin-based molecular tweezer for on-off fullerene recognition

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Chinese Chemical Letters 2024年第6期35卷 283-287页

作者： Zhimin Sun xin-Hui Guo Yue Zhao Qing-Yu meng Li-Juan xing he-Lue Sun College of Chemistry and Materials Science Hebei Key Laboratory of Organic Functional MoleculesHebei Normal UniversityShijiazhuang 050024China

herein,a novel molecular tweezer based on 2,2'-bipyridine-bridged porphyrin subunits was constructed for efficient fullerenes *** syn conformation of the molecule,which was obtained by Zn(Ⅱ)coordination,gives rise to a proper cavity to interact with fullerene guests to form a stable 1:1 complex in toluene *** exhibits distinct binding selectivity towards C_(60)over C_(70).Moreover,the fullerene recognition capacity can be adequately suppressed by importing H_(2)PO_(4)^(-)to competitively capture Zn(Ⅱ)along with syn-anti conformational ***,the molecular tweezer regenerated to bind the fullerene by introducing the Ca^(2+)into the ***,the association-disassociation process can be switched reversibly and repeatedly.

关键词： Molecular tweezer Fullerene recognition Supramolecular chemistry Conformation conversion Coordination

Unified method for typical gear failure modeling and stiffness calculation based on the matrix equation

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Frontiers of Mechanical Engineering 2024年第3期19卷 93-114页

作者： Fanshan meng xin ZHANG heng XIA Jiaxu WANG School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Mechanical Transmissions for Advanced Equipment Chongqing UniversityChongqing 400044China

The failure types in gear systems vary,with typical ones mainly including pitting,cracking,wear,and broken *** modeling and stiffness calculation methods have been developed for various gear failure types.A unified method for typical gear failure modeling and stiffness calculation is introduced in this study by considering the deviations in the time-varying meshing stiffness(TVMS)of faulty gears resulting from the use of different ***,a gear tooth is discretized into a large number of microelements expressed with a matrix,and unified models of typical gear failures are built by adjusting the values of the matrix *** values and positions of the microelements in the tooth failure model matrix have the same physical meaning as the parameter variables in the potential energy method(PEM),so the matrix-based failure model can be perfectly matched with ***,a unified method for TVMS is *** of healthy and faulty gears with pitting,wear,crack,and broken tooth is performed with the matrix equation,and the corresponding TVMS values are calculated by incorporating the matrix models with *** the basis of the results,the mechanism of typical fault types that affect TVMS is analyzed,and the conclusions are verified through the finite element *** developed unified method is a promising technique for studying the dynamic response characteristics of gear systems with different failure types because of its superiority in eliminating stiffness deviations.

关键词： gears matrix equation failure modeling TVMS calculation unified method

Impacts of angiotensin II on retinal artery changes in apolipoprotein E deficient mice

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International Journal of Ophthalmology(English edition) 2024年第1期17卷 16-24页

作者： Li-Hui meng Shi-Yu Cheng he Chen Yue-Lin Wang Wen-Fei Zhang Huan Chen xin-Yu Zhao You-xin Chen Department of Ophthalmology Peking Union Medical College HospitalChinese Academy of Medical SciencesBeijing 100730China Key Lab of Ocular Fundus Diseases Chinese Academy of Medical SciencesBeijing 100730China

AIM:To investigate the impacts of angiotensin II(Ang II)on retinal artery changes in apolipoprotein E deficient(apoE^(-/-))***:ApoE^(-/-)male mice were infused by minipumps with Ang II at 1000 ng/kg·min(Ang II group)or saline(control group)for *** were underwent ophthalmic fundus examination on day 0,14,and 28 of *** examination,ribonucleic acid(RNA)sequencing and local Ang II measurement of retinas were ***:Ophthalmic fundus examination showed Ang II infusion promoted the formation of retinal arterial aneurysm-like lesions on day *** coherence tomography revealed the ganglion cell and inner plexiform layer(GCIPL)thickness in the control group was significantly thinner than that in Ang II group(Phematoxylin-eosin staining demonstrated diffused swelling of GCIPL layer and its disordered structure in Ang II *** electron microscopy showed Ang II infusion caused aggravation of atherosclerotic lesions,including increased swelling,roughness,disorganization of the retinal vasculature,and vacuoles ***-sequencing and gene ontology enrichment analysis demonstrated that the structure and function of cellular membrane might be disturbed and visual function might be compromised by Ang *** local level of Ang II was higher in Ang II infusion group but did not show significant differences compared to the control group(P=0.086).CONCLUSION:Ang II infusion promotes the formation of retinal arterial aneurysm-like lesions in apoE^(-/-)mice,causing aggravation of atherosclerotic lesions,more severe disorganization of the retinal vasculature and disturbance of the cellular membrane.

关键词： angiotensin II retinal artery aneurysm apoE^(-/-)mice