The strengthening behavior of particle-reinforced metal±matrix composites (MMCp) is primarily attributed to the dislocation strengthening eect and the load-transfer eect. To account for these two eects in a uni®ed way, a new hybrid approach is developed in this paper by incorporating the geometrically necessary dislocation strengthening eect into the incremental micromechanical scheme. By making use of this hybrid approach, the particle-size-dependent inelastic deformation behavior of MMCp is given. Some comparisons with the available experimental results demonstrate that the present approach is satisfactory.

Two cationic polyacrylamides, PAA and PAD, were synthesized for sludge dewatering. The advanced instruments such as 1 H NMR, FTIR, and SEM were used to characterize the two copolymers. Their hydrophobic association properties in water were investigated by viscosimetry as well as the dewatering performance studied by the sludge dewatering experiment. The results showed that the optimum conditions for preparation of PAA were that the initiator concentration, urea concentration, molar ratio of AODBAC to AM, and irradiation time were 0.3‰, 1.0%, 10:90, and 60 min, respectively. Also, it was found that PAA had a stronger hydrophobic interaction with a lower intrinsic viscosity and longer dissolution time as well as a better dewatering performance. Furthermore, the charge neutralization and bridging effects were found to contribute much to the sludge dewatering by PAA in which the dewatering performance was able to be enhanced further by the hydrophobic interaction.

Palladacycles were found to be efficient catalysts for the reaction of oxabicyclic alkenes with terminal alkynes. A switch of reaction selectivity was realized using a palladacycle with an sp 2 or sp 3 C−Pd bond. Addition products were afforded predominantly using a palladacycle with an sp 3 C−Pd bond, while ring-opening compounds were the major products when palladacycles having an sp 2 C−Pd bond were used. DFT calculations revealed that the different trans effects of the sp 2 -C and sp 3 -C donors in palladacycles are responsible for the switch in selectivity.