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学术界 2015年第4期 286-292页

作者： gong yan Business School yancheng Teachers University Yancheng Jiangsu 224002

On the basis of the domestic and foreign research results,combined with the reality of yancheng,this paper puts forward that spatial layout is the key,the development of tourist product is the crux,the brand image is ... 详细信息

关键词：盐城市旅游产业文化产业江苏省整合研究成果空间布局旅游产品

Cosmological constraints on ultra-light axion fields

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Research in Astronomy and Astrophysics 2020年第4期20卷 99-106页

作者： Jian-Gang Kang yan gong gong Cheng Xuelei Chen Key Laboratory for Computational Astrophysics National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Centre for High Energy Physics Peking UniversityBeijing 100871China

Ultra-light axions(ULAs)with mass less than 10-20 eV have interesting behaviors that may contribute to either dark energy or dark matter at different epochs of the *** properties can be explored by cosmological observations,such as expansion history of the Universe,cosmic large-scale structure,cosmic microwave background,*** this work,we study the ULAs with mass around 10-33 eV,which means that the ULA field still rolls slowly at present with the equation of state w=-1 as dark *** investigate the mass and other properties of this kind of ULA field,we adopt the measurements of Type Ia supernova(SN Ia),baryon acoustic oscillation(BAO),and Hubble parameter H(z).The Markov Chain Monte Carlo(MCMC)technique is employed to perform the constraints on the ***,by exploring four cases of the model,we find that the mass of this ULA field is about 3×10-33 eV if assuming the initial axion fieldφi=*** also investigate a general case by assumingφi≤Mpl,and find that the fitting results ofφi/Mpl are consistent with or close to 1 for the datasets that we use.

关键词： cosmology dark energy cosmological parameters

Immersed Interface Finite Element Methods for Elasticity Interface Problems with Non-Homogeneous Jump Conditions

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Numerical Mathematics(Theory,Methods and Applications) 2010年第1期3卷 23-39页

作者： yan gong Zhilin Li Department of Mathematics Limestone College Gaffney SC 29340 USA. Center For Research in Scientific Computation and Department of Mathematics North Carolina State University Raleigh NC 27695-8205 USA.

In this paper,a class of new immersed interface finite element methods (IIFEM) is developed to solve elasticity interface problems with homogeneous and non-homogeneous jump conditions in two *** non-body-fitted meshes are *** homogeneous jump conditions,both non-conforming and conforming basis functions are constructed in such a way that they satisfy the natural jump conditions. For non-homogeneous jump conditions,a pair of functions that satisfy the same non-homogeneous jump conditions are constructed using a level-set representation of the *** such a pair of functions,the discontinuities across the interface in the solution and flux are removed;and an equivalent elasticity interface problem with homogeneous jump conditions is *** examples are presented to demonstrate that such methods have second order convergence.

关键词： Immersed interface finite element methods elasticity interface problems singularity removal homogeneous and non-homogeneous jump conditions level-set function.

Generation of Methyl Vinyl Ketone from Oxidation of Levulinic Acid Oxidized by Cupric Oxide Complex

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Chinese Journal of Chemistry 2012年第2期30卷 327-332页

作者： gong,yan Lin,Lu Zhang,Beixiao Department of Resources Science and Engineering State Key Lab of Pulp and Paper EngineeringSouth China University of TechnologyGuangzhouGuangdong 510640China Sehool of Energy Research Xiamen UniversityXiamenFujian 361005China

Methyl vinyl ketone （MVK） is a kind of high-value chemical which has been widely used in many fields. In this paper, it is formed from oxidation of levulinic acid--a hydrolysis product of biomass. Copper oxide supported on cerium dioxide （CuO/CeO2） and alumina （CuO/AI203） were prepared and used for the oxidation of levulinic acid （LA）. The oxidants were characterized by means of X-ray diffraction （XRD）, H2-temperature programmed reduction （H2-TPR） and atomic force microscope （AFM） techniques. CuO/CeO2 and CuO/A1203 show a different behav- ior with respect to pure CuO. The experiments revealed that CuO/CeO2 and CuO/AI203 can oxidize LA and get methyl vinyl ketone [yield of 15.5% detected by head space-gas chromatograph-mass spectrometer （HS-GC-MS）] under mild reactive conditions, while pure CuO oxidizes LA to produce butanone （MEK）.

关键词： LA oxidation MVK copper oxide cerium dioxide alumina

The silicate and carbon-rich models of CoRoT-7b,Kepler-9d and Kepler-10b

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Research in Astronomy and Astrophysics 2012年第6期12卷 678-692页

作者： yan-Xiang gong Ji-Lin Zhou Department of Astronomy ＆ Key Laboratory of Modern Astronomy and Astrophysics inMinistry of Education Nanjing University Nanjing 210093 China College of Physics and Electronic Engineering Taishan University Taian 271021 China

Possible bulk compositions of the super-Earth exoplanets CoRoT-7b, Kepler-9d, and Kepler-10b are investigated by applying a commonly used silicate model and a non-standard carbon model. Their internal structures are deduced using a suitable equation of state for the materials. The degeneracy problems of their compo- sitions can be partly overcome, based on the fact that all three planets are extremely close to their host stars. By analyzing the numerical results, we conclude： 1） the iron core of CoRoT-7b is not more than 27% of its total mass within lc~ mass-radius error bars, so an Earth-like composition is less likely, but its carbon rich model can be com- patible with an Earth-like core/mantle mass fraction; 2） Kepler-10b is more likely to have a Mercury-like composition, with its old age implying that its high iron content may be a result of strong solar wind or giant impact; 3） the transiting-only super-Earth Kepler-9d is also discussed. Combining its possible composition with the formation theory, we can place some constraints on its mass and bulk composition.

关键词： planets and satellites: general -- methods: numerical -- planets andsatellites: individual (CoRoT-7b Kepler-9d Kepler- 10b)

Implications of the Stellar Mass Density of High-z Massive Galaxies from JWST on Warm Dark Matter

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Research in Astronomy and Astrophysics 2024年第1期24卷 128-134页

作者： Hengjie Lin yan gong Bin Yue Xuelei Chen National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Science Center for China Space Station Telescope National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Center for High Energy Physics Peking UniversityBeijing 100871China

A significant excess of the stellar mass density at high redshift has been discovered from the early data release of James Webb Space Telescope(JWST),and it may require a high star formation ***,this will lead to large number density of ionizing photons in the epoch of reionization(EoR),so that the reionization history will be changed,which can arise tension with the current EoR *** dark matter(WDM),via the free streaming effect,can suppress the formation of small-scale structure as well as low-mass *** provides an effective way to decrease the ionizing photons when considering a large star formation efficiency in high-z massive galaxies without altering the cosmic reionization *** the other hand,the constraints on the properties of WDM can be derived from the JWST *** this work,we study WDM as a possible solution to reconcile the JWST stellar mass density of high-z massive galaxies and reionization *** find that,the JWST high-z comoving cumulative stellar mass density alone has no significant preference for either CDM or WDM *** using the observational data of other stellar mass density measurements and reionization history,we obtain that the WDM particle mass with mw=0.51_(-0.12)^(+0.22) keV and star formation efficiency parameter f_(*)^(0)> 0.39 in 2σ confidence level can match both the JWST high-z comoving cumulative stellar mass density and the reionization history.

关键词： Cosmology (cosmology:)dark matter (cosmology:)large-scale structure of universe

Clinical outcomes of small incision lenticule extraction versus femtosecond laser-assisted LASIK for myopia: a Meta-analysis

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International Journal of Ophthalmology(English edition) 2017年第9期10卷 1436-1445页

作者： Huan yan Li-yan gong Wei Huang yan-Li Peng Department of Ophthalmology the Second Affiliated Hospital of Chongqing Medical University Chongqing Medical University Department of Ophthalmology Chongqing Aier-Mega Eye Hospital Aier Eye Hospital Group Aier School of Ophthalmology Central South University

AIM：To evaluate the possible differences in visual quality between small incision lenticule extraction（SMILE）and femtosecond laser in situ keratomileusis（FS-LASIK）for ***：A Meta-analysis was *** were from previously reported comparative studies treated with SMILE versus *** Pub Med,EMBASE,Cochrane,Web of Science and Chinese databases（*** and CNKI）were searched in *** 2016 using Rev Man 5.1 version *** differences in visual acuity,aberration and biomechanical effects within six months postoperatively were ***-seven studies including 4223 eyes were ***：No significant differences were observed between SMILE and FS-LASIK in terms of the proportion of eyes that lost one or more lines of corrected distance visual acuity after surgery（P=0.14）,the proportion of eyes achieving an uncorrected distance visual acuity of 20/20or better（P=0.43）,the final refractive spherical equivalent（P=0.89）,the refractive spherical equivalent within±1.00diopter of the target values（P=0.80）,vertical coma（P=0.45）and horizontal coma（P=0.06）.Compared with the FSLASIK group,total higher-order aberration（P〈0.001）and spherical aberration（P〈0.001）were higher and the decrease in corneal hysteresis（P=0.0005）and corneal resistance factor（P=0.02）were lower in the SMILE ***：SMILE and FS-LASIK are comparable in efficacy,safety and predictability for correcting ***,the aberration in the SMILE group is superior to that in the FS-LASIK group,and the loss of biomechanical effects may occur less frequently after SMILE than after FS-LASIK.

关键词： Meta-analysis small incision lenticuleextraction femtosecond laser in situ keratomileusis myopia

Biochirality and parity violating energy difference

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Chinese Science Bulletin 2002年第7期47卷 603-608页

作者： Wang Wenqing gong yan Li Chen Department of Applied Chemistry College of Chemistry and Molecular EngineeringPeking University100871BeijingChina

Biochirality originates from the chiral influences in the universe. The parity non-conservation of weak neutral current, which takes place through the exchange of neutral boson Z0 combined with the long range Coulomb interaction in atoms and molecules, produces a parity violating energy difference (PVED). In this note, the fact is to be indicated that there is a λ -type second order phase transition of D- and L-alanine (valine) at a certain critical temperature Tc. The PVED is to be calculated as 6×10-5 eV/molecule by varieties of modern physical and chemical methods including the differential scanning calorimeter (DSC), SQUID, single crystal X-ray diffraction spectra, low-temperature 1H-MAS ssNMR, Raman spectra and ultrasonic measurement. A mechanism that differs from Salam’s hypotheses is also discussed here.

关键词： biochirality PVED D-/L-alanine D-/L-valine.

Forecasting Constraint on the f(R)Theory with the CSST SN Ia and BAO Surveys

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Research in Astronomy and Astrophysics 2024年第11期24卷 132-142页

作者： Jun-Hui yan yan gong Minglin Wang Haitao Miao Xuelei Chen National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Science Center for China Space Station Telescope National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Centre for High Energy Physics Peking UniversityBeijing 100871China

The f(R)modified gravity theory can explain the accelerating expansion of the late Universe without introducing dark *** this study,we predict the constraint strength on the f(R)theory using the mock data generated from the Chinese Space Station Telescope(CSST)Ultra-Deep Field Type Ia supernova(SN Ia)survey and wide-field slitless spectroscopic baryon acoustic oscillation(BAO)*** explore three popular f(R)models and introduce a parameter b to characterize the deviation of the f(R)theory from theΛCDM *** Markov Chain Monte Carlo method is employed to constrain the parameters in the f(R)models,and the nuisance parameters and systematic uncertainties are also considered in the model fitting ***,we also perform model comparisons between the f(R)models and theΛCDM *** find that the constraint accuracy using the CSST SN Ia+BAO data set alone is comparable to or even better than the result given by the combination of the current relevant observations,and the CSST SN Ia+BAO survey can distinguish the f(R)models from theΛCDM *** indicates that the CSST SN Ia and BAO surveys can effectively constrain and test the f(R)theory.

关键词： (cosmology:)cosmological parameters-cosmology theory-(cosmology:)dark energy

Soluble, Antibaterial, and Anticorrosion Studies of Sulfonated Polystyrene/Polyaniline/Silver Nanocomposites Prepared with the Sulfonated Polystyrene Template

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Chinese Journal of Chemistry 2017年第7期35卷 1157-1164页

作者： Guangfu Liao yan gong Changfeng Yi Zushun Xu Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials Ministry of Education Key Laboratory for The Green Preparation and Application of Functional Material Hubei University Wuhan Hubei 430062 China College of Chemistry and Chemical Engineering Fuzhou University Fuzhou Fujian 350108 China

In this work, multifunctional sulfonated polystyrene/polyaniline/silver （SPS/PANI/Ag） nanocomposites are prepared through using sulfonated polystyrene （SPS） spheres as templates and utilizing polyvinylpyrrolidone （PVP） as reducing agent and stabilizing agent. Our method is an environmentally friendly method because no toxic rea- gents are added during the preparation process. Fourier transform infrared spectrum （FTIR）, field emission scanning electron microscopy （FESEM）, and energy disperse spectroscopy （EDX） results confirmed the formation of PS spheres, SPS spheres, SPS/PANI nanocomposites, and SPS/PANI/Ag nanocomposites. Powder X-ray diffraction （XRD） patterns indicate that the obtained Ag nanoparticles are crystalline. Solubilities measurements show that SPS/PANI/Ag nanocomposites have improved solubilities when compared to pure PANI in common organic sol- vents and deionized water. Antibacterial studies show that SPS/PANI/Ag nanocomposites can greatly inhibit the growth of Escherichia coli and Staphylococcus aureus. Anticorrosion studies show that the incorporation of SPS/PANI/Ag nanocomposites in waterborne alkyd resin can greatly promote＇the anticorrosive efficiency of water- borne alkyd resin.

关键词： sulfonated polystryrene polyaniline silver antibacterial anticorrosion