牡蛎肽-锌纳米粒的形成及稳定作用力

探讨牡蛎肽-锌纳米粒的形成条件及稳定作用力。通过透光率检测初步筛选牡蛎肽-锌纳米粒形成的条件,用粒径分析和电镜观察方法确认纳米粒的形成。通过次级键破坏实验分析稳定纳米颗粒空间结构的作用力。结果表明,在牡蛎肽中加入0.5%~0.9%的硫酸锌后,将体系p H调至6.0~11.0,即可制得粒径为28~102 nm的牡蛎肽-锌纳米粒。锌是纳米粒的必需组分,疏水作用和静电相互作用是稳定纳米粒的关键作用力。牡蛎肽-锌纳米粒有望成为新型补锌制剂。

FEM for Stability Analysis Against Overturning of Portal Water Injection Sheet Pile

Portal water injection sheet pile (PWISP), as a retaining wall, appeared in seashore engineering in 2000. Although there have been many systematic methods addressing the issue, there are very few focusing on the new structure because of the difficulties in defining the earth pressure between the two piles. A new method is proposed in this paper to obtain the earth pressure between the PWISPs. Stability analysis against overturning follows as a consequence. Using Finite Element Analysis (FEA) software ANSYS, both the nonlinear characteristics of the soil and those of the contact elements are taken into account to obtain the earth pressure distribution on the contact surface. Based on the results of the FEA, Rankin’s theory and the slip plane theory, the formula of the earth pressure on the inner surfaces between the piles is given. Assuming the PWISP as the analysis object and the earth pressure as an outside force acting upon it, the equation of stability against overturning of the PWISP is presented. Finally, some parameters are discussed about the stability of the PWISP against overturning, such as the embedded depth of the front pile, the distance between the two rows of piles, the internal friction angle and the cohesion of the earth. The results show that the increase of the cohesion and the internal friction angle will decrease the distance and the embedded depth, and therefore enhance the stability against overturning. Specifically, when the distance is 1/3-2/3 of the maximal excavation depth, the two rows of piles give the best performance in stability.

Computation of Ship Hydrodynamic Interaction Forces in Restricted Waters using Potential Theory

A computer code based on the double-body potential flow model and the classic source panel method has been developed to study various problems of hydrodynamic interaction between ships and other objects with solid boundaries including the seabed. A peculiarity of the proposed implementation is the application of the so-called ＂moving-patch＂ method for simulating steady boundaries of large extensions. The method is based on an assumption that at any moment just the part of the boundary （＂moving patch＂） which lies close to the interacting ship is significant for the near-field interaction. For a specific case of the fiat bottom, comparative computations were performed to determine optimal dimensions of the patch and of the constituting panels based on the trade-off between acceptable accuracy and reasonable efficiency. The method was applied to estimate the sway force on a ship hull moving obliquely across a dredged channel. The method was validated for a case of ship-to-ship interaction when tank data were available. This study also contains a description of a newly developed spline approximation algorithm necessary for creating consistent discretizations of ship hulls with various degrees of refinement.

Inclusion behavior of oxybutynin with hydroxypropyl-β-cyclodextrin

Inclusion behavior of oxybutynin （OBN） with hydroxypropyl-β-cyclodextrin （HP-β-CD） was investigated by ultraviolet absorption spectrum and fluorescence spectrum. A reliable determination of the complex stoichiometry was provided by the continuous variation technique. Alcohol was added to further investigate the mechanism of the inclusion behavior. Thermodynamic constants AG, AH and AS for inclusion interaction of OBN and HP-β-CD were determined. The results show that host-guest complex with molar ratio of 1：1 is formed, and inclusion stability constant between OBN and HP-β-CD is 54.9 L/mol determined by ultraviolet spectrum and 11.1 L/mol determined by fluorescence spectrum. OBN has weak binding ability with HP-β-CD in aqueous solution （stability constant 〈102 L/mol） and addition of alcohol leads to a decrease of stability constant, which indicates that the hydrophobic force contributes to the inclusion process. AG, AH and AS are all less than zero, which indicates that the inclusion process is a spontaneous and exothermic process.

Constructing hydrophobic protection for ionic interactions toward water,acid,and base-resistant self-healing elastomers and electronic devices

Dynamically crosslinked materials generally lose their self-healing ability and mechanical robustness in aqueous,acidic,and basic environments due to disruption of their dynamic interactions and bonds.Herein,a micelle-like structure with a hydrophobic outer layer is used to protect ionic interactions.This structure ensures the self-healing and long-term stability of the ionically crosslinked elastomers in aqueous,acidic,and basic environments.The elastomer possesses a tensile strength of 6.7 MPa and a strain at break of 1400%,which is superior to the existing waterproof selfhealing elastomers.The strain sensors and dielectric actuators based on the elastomer are highly stable and self-healable,even in extremely harsh environments.This design strategy of hydrophobic protection for dynamic interactions is quite general,allowing it to be extended to other self-healing materials.

Modulational Instability of Spinor Condensates in an Optical Lattice

We obtain analytically the static states and corresponding collective-excitation spectra of a quasi-onedimensional spin-1 condensate modulated by a long-wavelength optical lattice in the weak lattice limit. It is demonstrated that both ferromagnetic and antiferromagnetic condensates may exhibit dynamical instability, which agree with the results with numerical simulation. In the homogeneous limit, our resuRs reduce to the previous results for homogeneous spinor condensates, i.e., dynamical instability can occur only for ferromagnetic interaction and an antiferromagnetic condensate is always dynamically stable.