Research on Bearing Capacity Calculation Method of Large Diameter Cylinder in Soft Clay

A large diameter cylinder inserted in soils is a new type of engineering structures used in offshore and port engineering. The mechanism of its bearing capacity and the analysis of its stability are important to its design and applications. In this paper, the finite element method is used to analyze the reacting forces of the soft soil foundation on the structure under the wave action. A simplified method is proposed, based on the plastic limit method, for the safety and stability analysis. Our analysis shows that the assumptions made in this paper and the mechanism used are reasonable, and the results obtained are appropriate. The calculation method is very efficient and can be used to evaluate main parameters of the structure in its preliminary designs.

Post-cyclic Strength Degradation of Undisturbed and Remolded Marine Silty Clay

A series of static and cyclic-static tri-axial compression tests under consolidated-undrained conditions are carried out to study the characteristics of post-cyclic strength of the undisturbed and the remolded samples of marine silty clay. It is found that the post-cyclic monotonic strength decreases if the cyclic strain or pore pressure is over a certain value. The maximum degradation is 10% for undisturbed samples while 70% for remolded ones. The relationship between normalized undrained shear strength and apparent overconsolidation ratio, which is determined by the excess pore pressure induced by cyclic loading, is also established. Static consolidated-undrained tests on overconsolidated remolded samples are also performed. It is proposed that the static consolidated-undrained tests may be substituted for the cyclic-static consolidated-undrained tests if the post-cyclic strength degradation of remolded silty clay is needed to be evaluated simply.

Dextran and protamine-based solid lipid nanoparticles as potential vectors for the treatment of X-linked juvenile retinoschisis

This is a copy of an article published in the Human gene therapy © 2012 copyright Mary Ann Liebert, Inc.; Human gene therapy is available online at: http://online.liebertpub.com.

Metal-Free Polymethyl Methacrylate (PMMA) Nanoparticles by Enamine "Click" Chemistry at Room Temperature

"Click" chemistry has become an efficient avenue to unimolecular polymeric nanoparticles through the self-crosslinking of individual polymer chains containing appropriate functional groups. Herein we report the synthesis of ultra-small (7 nm in size) polymethyl methacrylate (PMMA) nanoparticles (NPs) by the "metal-free" cross-linking of PMMA-precursor chains prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization containing beta-ketoester functional groups. Intramolecular collapse was performed by the one-pot reaction of beta-ketoester moieties with alkyl diamines in tetrahydrofurane at r.t. (i.e., by enamine formation). The collapsing process was followed by size exclusion chromatography and by nuclear magnetic resonance spectroscopy. The size of the resulting PMMA-NPs was determined by dynamic light scattering. Enamine "click" chemistry increases the synthetic toolbox for the efficient synthesis of metal-free, ultra-small polymeric NPs.

Design and synthesis of biofunctional magnetic/fluorescent glyco-nanoparticles and quantum dots and their application as specific molecular imaging probes

206 p.