This study explores Taiwanese mathematics teachers' critiques of a series of geometry textbooks for grades 8 and 9. Two hundred seventy-four critiques from 143 mathematics teachers were analyzed by referring to six attributes of abstraction. Through analysis and interpretation of these critiques, the meaning of each attribute was refined, and their features were revealed. Possible beliefs-in-critiquing related to the features were discussed. This study contributes to the literature by advancing understanding of mathematics teachers' critiques of textbooks. We conclude with a discussion of the methodological and educational implications of teachers' critiques as well as how critiques of teaching materials can influence teacher education.

A new crosslinked amphoteric hydrogel (PAC) was synthesized and evaluated as an internal curing agent of concrete. PAC was prepared from acrylamide (AM) and 4-(2-((carboxylatomethyl)dimethylammonio)ethoxy)24-oxobut-2-enoate (CMD) through free-radical polymerization by using ammonium persulfate (APS) as an initiator and methylene-bisacrylamide (MBA) as a crosslinker. The structure of the prepared polymer was verified by the IR spectra. The effects of the polymerization variables on the swelling capacity of PAC were investigated. The water absorbency of PAC was found to increase with increasing CMD/AM ratio, reach a maximum value, and decrease afterword. Increase of either APS or MBA content decreased the water absorbency. The highest water absorbency of PAC hydrogel (P7) achieved in deionized water, 0.1M NaCl solutions and 0.1M CaCl 2 solutions, was 306 g/g, 32 g/g, and 22 g/g, respectively. Compared with a commercial acrylate-based hydrogel 283HA, P7 was less sensitive to the existence of Ca 21 ions in cement pore solutions, and more effective in reducing the cracking tendency of cement pastes. Finally, mortars incorporated with proper amounts of P7 showed smaller drying shrinkage and higher compressive strength than that without hydrogel present. V C 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42175.