[en] In this study, the effect of different crosslinkers including glutaraldehyde (GTA), genipin (GIP) and procyanidine (PA) on the properties of the electrospun gelatin membranes was compared. The water-resistant ability of the membranes could be significantly improved after being crosslinked with PA at T > 40 °C. In contrast with GTA and GIP, the PA-crosslinking process did not apparently affect the fibrous structure, and induced the lowest shrinkage of the membranes. At the concentration of 5% of PA, the ultimate tensile strength and elongation of the hydrated membrane were 0.87 MPa and 148%, respectively, which were higher than those of the GIP-crosslinked counterparts. In addition, the PA-crosslinked membranes displayed the highest resistance to pepsin degradation, and fibroblast cells could migrate deeper into the interior of the membranes due to the good preservation of the fibrous structure during the cell culture process. (paper)

[en] A boron solution injection system is used as the standby liquid control system for 5MW THR. It is necessary for design of a nuclear reactor mixing with the coolant. This paper describes a visible study, which obviously displays the boron mixing with water in the main loop for differnt values of (ρ_jω_j)/(ρ_pω_p)

[en] A pulse injection stimulus-response technique to study the boron mixing and transport performance after boron-loaded liquid was injected into the reactor core is described. The experiment was carried out in a simulation device. The simulation medium was used. The experimental results show that the lower plenum where the injection point located can be simplified to one scale inertial unit and the movement of boron mixture was only transported after it had entered into the fuel elements. The definition of boron initiative mixing fraction η is also given. By using relating data a dimensionless equation is obtained

[en] This paper proposes a non-intrusive interval uncertainty analysis method for estimation of the dynamic response bounds of nonlinear systems with uncertain-but-bounded parameters using polynomial chaos expansion. The conventional interval arithmetic and Taylor series methods usually lead to large overestimation because of the intrinsic wrapping effect, especially for the multidimensional and non-monotonic problems. To overcome this drawback, a novel polynomial chaos inclusion function, based on the truncated polynomial chaos expansion, is proposed in the present work to evaluate interval functions. In this method, the Legendre polynomial in interval space is employed as the trial basis to expand the interval processes, and the polynomial coefficients are calculated through the collocation method. Two examples show that the polynomial chaos inclusion function is capable of determining tighter enclosures of the true solutions and effectively dealing with the wrapping effect. The response of nonlinear systems with respect to interval variables is approximated by the polynomial chaos inclusion function, through which the supremum and infimum of the dynamic responses over all time iteration steps can be easily estimated by an appropriate numerical solver. Four dynamics examples described by ordinary differential equations demonstrate the effectiveness, feasibility, and efficiency of the proposed interval uncertainty analysis method compared with other methods.

[en] In this work, an effective approach to control the thickness and porosity of porous gold nanonetworks (PGNs) was demonstrated. The 3-dimensional (3-D) PGNs were accomplished by repeated overlaying of two-dimensional (2-D) monolayer gold nanonetworks which assembled at the pentanol/water interface. The porosity of the PGNs can be improved by increasing the number of layers, which greatly enhances the intralayer and interlayer plasmon coupling and the mass diffusion of the analyte molecules, resulting in an improved sensitivity for SERS and glucose detection. In addition, the current approach also offered an effect method to produce 3-D porous nanostructures through the self-assembly of the isolated nanoparticles (NPs). (papers)

[en] In this paper, a Crank–Nicolson-type finite difference method is proposed for computing the soliton solutions of a complex modified Korteweg–de Vries (MKdV) equation (which is equivalent to the Sasa–Satsuma equation) with the vanishing boundary condition. It is proved that such a numerical scheme has the second-order accuracy both in space and time, and conserves the mass in the discrete level. Meanwhile, the resulting scheme is shown to be unconditionally stable via the von Nuemann analysis. In addition, an iterative method and the Thomas algorithm are used together to enhance the computational efficiency. In numerical experiments, this method is used to simulate the single-soliton propagation and two-soliton collisions in the complex MKdV equation. The numerical accuracy, mass conservation and linear stability are tested to assess the scheme’s performance. (paper)

[en] Highlights: • The proposed IFVE method is second-order accuracy in the $L^{\infty }$ norm for the elliptic interface problems for all examples tested. • The new method can deal with the case when the solution or its normal derivative is discontinuous. • The new method can handle the case where the interface has sharp edge or meets with the vertices. In this paper, we propose a new immersed finite volume element method to solve elliptic problems with discontinuous diffusion coefficient and sharp-edged interfaces on Cartesian mesh. The method uses the non-traditional immersed finite volume element method together with additional immersed finite element function on interface element. It can deal with the case when the solution or its normal derivative is discontinuous. Extensive numerical experiments for various problems show that the new method is approximate second-order convergence in the $L^{\infty }$ norm for piecewise smooth solutions, and more than 1.65th order accuracy is observed for solution with singularity.

[en] In this paper, Cu and Ce were added to melt-spun Al–Ag precursor alloys to refine the microstructures of nanoporous Ag and Ag/CeO₂ composite catalysts for NaBH₄ oxidation. After the precursor alloys were dealloyed in 20% NaOH, calcined in air and corroded again in 50% NaOH, Ag₂Al in the precursor alloys was completely removed, and refined nanoporous Ag could be obtained; from this process, the finest microstructures were exhibited by Al₈₄Ag₈Cu₈. When more than 0.3% Ce was added to the Al₈₄Ag₈Cu₈ ribbons, a refined nanoporous Ag material that consisted of CeO₂ nanorods interspersed between Ag ligaments was obtained. Electrochemical measurements indicated that the catalytic properties were clearly increased due to the Cu addition to the Al–Ag alloy. After Ce was added to the Al₈₄Ag₈Cu₈ ribbons, the catalytic properties of the resulting material were further improved. In regard to melt-spun Al₈₄Ag₈Cu₈Ce_0.5, the obtained nanoporous Ag/CeO₂ presented the best properties, and its current density was 2.5 times that of Al₈₄Ag₈Cu₈, 3.1 times that of Al₉₀Ag₈Cu₂ and 2.3 times that of Ag/Ce from the Al₇₉Ag₁₅Ce₆ precursor alloy without Cu. It was believed that the core–shell structure composed of Ag and Cu-rich phases formed during dealloying could limit the diffusion of Ag and prevent the coarsening of Ag ligaments. Thus, the refined microstructures could provide a large specific surface or additional active sites for the catalytic reaction. Strong interactions resulted from the many interfaces between the Ag ligaments and interspersed CeO₂ nanorods, and the more effective utilization of Ag was due to the decomposition of Ag₂Al; this result was the key reason for the clear improvement in catalytic performance. (paper)

[en] Self-assembling Au mesoflower arrays are prepared using a polymethylmethacrylate (PMMA) template on an iron substrate via a combined top-down/bottom-up nanofabrication strategy. The PMMA template with the holes around 300–500 nm in diameter is first fabricated by using polymer blend lithography on iron substrates, and the highly homogeneous Au mesoflower arrays with less than 10 nm intraparticle gaps are subsequently obtained by an in situ galvanic reaction between HAuCl₄ solution and the iron substrate under optimal stirring of the solution as well as reaction time. Owing to the unique mesostructures and uniformity, Raman measurements show that the gold mesoflower arrays obtained demonstrated a strong and reproducible surface enhanced Raman scattering (SERS) enhancement on the order of ∼10⁷–10⁸. The development of a SERS substrate based on the Au mesoflowers with high spatial density of hot spots, relatively low cost and facial synthesis provides a novel strategy for applications in chemical and biomolecular sensing. (paper)

[en] Highlights: → The ultrafine CuO nanowires were controlled synthesized by a simple solution route. → CuO nanowires exhibit high capacity, superior cyclability and improved rate capability. → Voltage-capacity curves show larger extra reversible reactions at low potentials in CuO nanowires. → CV curves show lower over-potential in CuO nanowires. - Abstract: A simple solution route is used to synthesize ultrafine Cu(OH)₂ nanowires by restraining the morphology transformation of early formed 1D nanostructure. The obtained ultrafine nanowires can be well preserved at a low temperature structure transformation in solid state. As anode material for lithium-ion batteries, the ultrafine CuO nanowires exhibit high reversible capacity, superior cycling performance and improved rate capability. The improved electrochemical properties of CuO nanowires are ascribed to their ultrafine size which lead to the reduced over-potential, extra reversible reactions at low potentials and improved interface performance between the electrode and electrolyte.