4,011 research outputs found

    Towards Understanding Astrophysical Effects of Nuclear Symmetry Energy

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    Determining the Equation of State (EOS) of dense neutron-rich nuclear matter is a shared goal of both nuclear physics and astrophysics. Except possible phase transitions, the density dependence of nuclear symmetry \esym is the most uncertain part of the EOS of neutron-rich nucleonic matter especially at supra-saturation densities. Much progresses have been made in recent years in predicting the symmetry energy and understanding why it is still very uncertain using various microscopic nuclear many-body theories and phenomenological models. Simultaneously, significant progresses have also been made in probing the symmetry energy in both terrestrial nuclear laboratories and astrophysical observatories. In light of the GW170817 event as well as ongoing or planned nuclear experiments and astrophysical observations probing the EOS of dense neutron-rich matter, we review recent progresses and identify new challenges to the best knowledge we have on several selected topics critical for understanding astrophysical effects of the nuclear symmetry energy.Comment: 77 pages. Invited Review Article, EPJA (2019) in pres

    RESEARCH ON EFFICIENCY OF PRIMARY HEALTHCARE SERVICE OF SHANGHAI IN CHINA

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    Object: The article researches on efficiency of Shanghai Community Health Service (SCHS) and establishes production function of SCHS.Method: Establishing the production function of SCHS by Weighted Least Squares Estimation .Result: 1. Formulating the reasonable production function of SCHs based on Cobb: Douglas (C-D) function. 2. The article reveals SCHS production function with constant returns to scale.Conclusion: 1. Increasing human resource investment is a key factor for raising SCHS.2.Strenghten management and explore an efficient service model will improve SCHS level

    Effect of terrains on the volatiles of Cabernet Sauvignon wines grown in Loess Plateau region of China

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    Volatile compounds of young Cabernet Sauvignon wines from the flat and slope lands grown in Loess Plateau region (China) were investigated in this research. Among the volatile compounds analyzed by headspace solid phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS), a total of 43 and 45 volatile compounds were identified and quantified in the flat and slope lands wines, respectively. In the volatiles detected, higher alcohols formed the most abundant group in the aroma components of two wines, followed by esters and fatty acids. According to their odor active values (OAVs) and relative odor contribution (ROC), the aromatic profiles for two wines were similar, showing only quantitative but not qualitative differences. Ethyl octanoate, ethyl hexanoate and isoamyl acetate were found to jointly contribute to 98.8 and 99.2% of the global aroma of the flat and slope wines, respectively. These odorants are associated with “fruity’’ and ‘‘ripe fruit’’ odor descriptors. Wine from flat land with higher OAVs of ethyl octanoate and isoamyl acetate seems to have more intense fruity aromas (pineapple, pear and banana), with floral notes.Keywords: Cabernet Sauvignon wines, volatiles, terrains, Loess Plateau region, headspace solid phase microextraction (HS-SPME), gas chromatography-mass spectrometry (GC-MS

    Constraining the Skyrme effective interactions and the neutron skin thickness of nuclei using isospin diffusion data from heavy ion collisions

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    Recent analysis of the isospin diffusion data from heavy-ion collisions based on an isospin- and momentum-dependent transport model with in-medium nucleon-nucleon cross sections has led to the extraction of a value of L=88±25L=88\pm 25 MeV for the slope of the nuclear symmetry energy at saturation density. This imposes stringent constraints on both the parameters in the Skyrme effective interactions and the neutron skin thickness of heavy nuclei. Among the 21 sets of Skyrme interactions commonly used in nuclear structure studies, the 4 sets SIV, SV, Gσ_\sigma, and Rσ_\sigma are found to give LL values that are consistent with the extracted one. Further study on the correlations between the thickness of the neutron skin in finite nuclei and the nuclear matter symmetry energy in the Skyrme Hartree-Fock approach leads to predicted thickness of the neutron skin of 0.22±0.040.22\pm 0.04 fm for 208^{208}Pb, 0.29±0.040.29\pm 0.04 fm for 132^{132}Sn, and 0.22±0.040.22\pm 0.04 fm for 124^{124}Sn.Comment: 10 pages, 4 figures, 1 Table, Talk given at 1) International Conference on Nuclear Structure Physics, Shanghai, 12-17 June, 2006; 2) 11th China National Nuclear Structure Physics Conference, Changchun, Jilin, 13-18 July, 200

    Experimental Study on the Feasibility of Using Water Glass and Aluminum Sulfate to Treat Complications in High Liquid Limit Soil Subgrade

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    The feasibility of using water glass and aluminum sulfate to treat high liquid limit soil subgrade diseases is studied through laboratory experiments, and the following results were observed. After improving the high liquid limit clay with water glass and aluminum sulfate, the liquid limit decreases, the plastic limit increases, and the plasticity index decreases. Compared with untreated soil, the clay content of the improved soil decreases, while the silt and coarse contents increase. The absolute and relative expansion rates of the improved soil are both lower than those of the untreated soil. With the same number of dry and wet cycles, the decreased degrees of cohesion and internal friction angle of the improved soil are, respectively, one-half and one-third of those of the untreated soil. After three dry and wet cycles, the California bearing ratio (CBR) of the untreated soil does not meet the requirements of specifications. However, after being cured for seven days and being subjected to three dry and wet cycles, the CBR of the improved soil, with 4% water glass solution and 0.4% aluminum sulfate, meets the requirements of specifications

    Internet Platform Enterprises and Farmers Digital Literacy Improvement

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    Agricultural and rural informatization is the strategic commanding heights of agricultural and rural modernization, and the improvement of farmers' digital literacy is the core task of digital rural construction. In the digital age, the development of the platform economy has given Internet platform enterprises a new connotation of social responsibility to improve farmers' digital literacy. By strengthening platform governance to enhance farmers' willingness to use digital, promoting science and technology for good to enhance farmers' digital use skills, and innovating digital services to enhance farmers' digital use effects, Internet platform enterprises ultimately achieve the purpose of improving farmers' digital literacy
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