[en] To obtain accurate solubility of CO_2 is one of problems that need solutions urgently in CO_2 sequestration within saline groundwater. However, there are few data published for solubility of CO_2 under geological sequestration conditions. In order to fill the gap of the experimental study, the solubility of CO_2 in five formations of Erdos Basin was explored in this research. Groundwater samples in five reservoirs were carried out through an observation well in the Erdos Basin. The chemical composition was determined and experiments measuring CO_2 solubility were carried out in the synthetic water samples. Krichevsky-Kasarnovsky equation was established to analyze the experimental data. The relationship between concentration of K"+, Na"+, Ca"2"+ , Mg"2"+ and the solubility of CO_2 was analyzed and an excellent liner fit was found, which quantifies the impact of ions on the solubility of cO_2. Solubility data were compared to the model prediction over the temperature and pressure ranges of 318 ∼ 348 K and 8 ∼ 11 MPa. The average absolute deviation is 2.11%. The results can be used as a parameter for the evaluation of the CO_2 storage capacity in deep saline aquifer of Erdos Basin. (authors)

[en] The transition strain-rate represents the start of significant contributions from radial inertia-induced lateral confinement to the axial compressive strength of the tested materials. However, it has been misinterpreted for decades by many studies as the start of significant strain-rate effect on the dynamic uniaxial compressive strength of the tested materials. Based on the dimensional analysis and numerical and experimental data, a semi-empirical formula to determine the transition strain-rates for various engineering materials is proposed. Errors in SHPB tests due to the contribution of the lateral confinement effect are estimated. It is found that, except for metals, transition strain-rates of concrete-like, rock-like and polymeric materials are unfortunately located in the valid range of SHPB tests that has been commonly accepted by research communities. Thus SHPB tests cannot be treated as valid measurements under uniaxial stress state when strain-rates are greater than the transition strain-rate

[en] A generalized Anderson single-impurity model with off-site Coulomb interactions is derived from the extended three-band Hubbard model, originally proposed to describe the physics of the copper-oxides. Using the abelian bosonization technique and canonical transformations, an effective Hamiltonian is derived in the strong coupling limit, which is essentially analogous to the Toulouse limit of the ordinary Kondo problem. In this limit, the effective Hamiltonian can be exactly solved, with a mixed valence quantum critical point separating two different Fermi liquid phases, i.e. the Kondo phase and the empty orbital phase. In the mixed valence quantum critical regime, the local moment is only partially quenched and X-ray edge singularities are generated. Around the quantum critical point, a new type of non-Fermi liquid behaviour is predicted with an extra specific heat C_imp ∼ T^1/4 and a singular spin-susceptibility χ_imp ∼ T^-3/4. At the same time, the effective Hamiltonian under single occupancy is transformed into a resonant-level model, from which the correct Kondo physical properties (specific heat, spin susceptibility, and an enhanced Wilson ratio) are easily rederived. Finally, a brief discussion is given to relate these theoretical results to observations in U Pd_xCu_5-x (x=1, 1.5) alloys, which show single-impurity critical behaviour consistent with our predictions. (author). 30 refs

[en] Hydrogels, promising biological materials, need to have both strong mechanical properties and also inherent self-healing properties. In this work a double cross-linked network (DN) hydrogel was designed and prepared by combining a Diels-Alder click reaction and coordination effects. This DN hydrogel had good thermodynamic properties, anti-EDTA performance and self-healing properties. In addition, the mechanical properties, swelling properties and surface morphology of DN hydrogels can be controlled by adjusting the ratio of Fe³⁺-catechol. The adjustment of pH value can change the color, crosslinking mode and mechanical properties of the DN hydrogel. This smart hydrogel created from DA click chemistry and coordination effects has significance for guiding the design of new hydrogels with good mechanical properties, self-healing properties and controlled cross-link density. - Highlights: • A double cross-linked network (DN) was designed and prepared by combining a Diels-Alder click reaction and coordination effects. • The obtained DN hydrogel has the advantages of controlled crosslinking density and self-healing. • The effects of the ratio of Fe³⁺-catechol and pH on the hydrogels are explored in detail.

[en] Using the density matrix renormalization group technique, we calculate numerically the low energy excitation spectrum and magnetization curve of the spin-1 antiferromagnetic chain in a staggered magnetic field, which is expected to describe the physics of R₂BaNiO₅(R ≠ Y) family below the Neel temperature of the magnetic rare-earth (R) sublattice. These results are valid in the entire range of the staggered field, and agree with those given by the non-linear σ model study for small fields, but differ from the latter for large fields. They are consistent with the available experimental data. The correlation functions for this model are also calculated. The transverse correlations display the anticipated exponential decay with shorter correlation length, while the longitudinal correlations show explicitly the induced staggered magnetization. (author)

[en] Manganese-activated willemite (α-Zn_2−xMn_xSiO₄; x = 0.05–0.20) phosphor thin films with bright green light emission were deposited on silicon wafers by a sol–gel process. Zinc chloride, tetraethylorthosilicate, and manganese chloride were employed as precursors. The sol–gel transition, crystallization process and photoluminescence of processed films were investigated. The level of manganese doping did not greatly affect the crystallinity, but did affect the gelation rate and luminescence of films. X-ray diffraction and infrared spectrum studies revealed that single-phase willemite started to crystallize at around 600 °C. After thermal annealing at 600°–1200 °C, the crystallinity of films increased with increasing heating temperature and thickness of films. The emission intensity of the film was strongly related to the crystallinity and deposition conditions. Controlling the dopant content, number of coating layers and annealing temperature could significantly enhance the brightness of the green emission. The luminescence properties of α-Zn₂SiO₄:Mn films are characterized by fluorescence spectra and decay lifetime measurements.

[en] By adding a low-softening-point Li₂O-B₂O₃-SiO₂-CaO-Al₂O₃ (LBSCA) glass, the voltage-tunable Ba_0.6Sr_0.4TiO₃ (BST64) ceramics can be densified at 900degC, which is 400-500degC lower than the temperature for producing the pure BST64. This is caused by liquid-phase sintering and an interfacial reaction taking place at the interface of LBSCA/Ba_0.6Sr_0.4TiO₃. For the samples with 10-35vol% LBSCA glass, a high relative sintered density of >95% is obtained at 900degC and the resulting dielectric composites have a dielectric constant and loss at 1 MHz in the ranges of 1040-145 and 0.4-1.0%, respectively. The voltage tunability of the resulting LBSCA+BST64 dielectric at 1 MHz and 1 kV/mm is in the range of 0.8-8%, which exhibits a decreasing trend with increasing LBSCA content. (author)

[en] During a core-collapse supernova, absorption of ν_e emitted from the protoneutron star by protons in the hydrogen envelope produces neutrons and positrons. Neutron capture on protons and positron annihilation then produce γ rays of 2.22 and 0.511 MeV, respectively. We calculate the fluxes of these γ rays expected from a supernova with an 11M_· progenitor. The flux from neutron capture on protons exponentially decays on a time scale of 564 s, which is determined by neutron decay and capture on protons and ³He nuclei. The peak flux is 2.38x10^-7 cm^-2 s^-1 for a supernova at a distance of 1 kpc. In contrast, the γ-ray flux from positron annihilation follows the time evolution of the ν_e luminosity and lasts for ∼10 s. The peak flux in this case is 6.8x10^-5 cm^-2 s^-1 for a supernova at a distance of 1 kpc. Detection of the above γ-ray fluxes is beyond the capability of current instruments, and perhaps even those planned for the near future. However, if such fluxes can be detected, they not only constitute a new kind of signal that occurs during the gap of several hours between the neutrino signals and the optical display of a supernova, but may also provide a useful probe of the conditions in the surface layers of the supernova progenitor

[en] In this paper, the collective behaviors in a globally coupled system consisting of harmonic oscillators with damping fluctuation modeled as dichotomous noise are investigated. First, the first and second moments of mean field and the fluctuation of single particle are introduced to describe the collective behaviors of the system. Then, based on the moment method and Shapiro–Loginov formula, the stability conditions for the coupled system and the analytical expressions for the output amplitude are obtained. Finally, according to the analytical expressions and numerical simulations based on the stochastic Taylor expansion, the collective behaviors are discussed, including synchronization and stochastic resonance. Stationary regime plays an important role in this coupled system. In the stationary regime, all the particles move synchronously and the output amplitudes are bounded which can be reliably estimated, whereas in the non-stationary regime, the first moment cannot be reliably estimated and the distribution of realizations is characterized by fat tail.

[en] The research applies PCSWMM, a commercial rainwater analysis calculation software in the assessment of flood defending ability of a nuclear facility site. The double drainage systems analysis model was built up to simulate the process of under ground drainage and surface runoff in extreme rainfall in a nuclear facility site. The simulating result displays, the surface maximum water depth of the nuclear facility site 500 years at once is 0.13 meters. The calculating result is identical with the calculating result 0.10 meters of inference formula method. It can reflect the actual flood defense ability. The double-drainage-systems calculation method in PCSWMM could simulate the maximum flooding water depth result very well. (authors)