The thermal degradable poly(alkoxyamine) was synthesized through a novel nitroxide radical coupling step growth polymerization (NRC-SGP) mechanism. The monomers of 1,4-phenylene bis(2-bromo-2-methylpropanoate) (monomer 1) and 1,4-phenylene bis(2-bromopropanoate) (monomer 1′) with two bromide groups and 1,6-di(4-(2,2,6,6-tetramethylpiperidine-1-oxyl))-hexa-2,4-diyne (monomer 2) with two nitroxide radicals were first designed and synthesized. Then the NRC-SGP mechanism was investigated in detail by optimizing the factors such as polymerization time, temperature, solvents, catalysts, ligand, monomer concentration, and structures connected to halogen groups. The results showed that the termination by disproportionation was the major side reaction in the NRC-SGP mechanism, and the lower temperature (25 °C) would favor an important contribution. The proper combination of all factors could lead to an ideal NRC-SGP procedure. Finally, the thermal stability of formed poly(alkoxyamine) was monitored by TG, DSC and SEC instruments, and the results showed that the poly(alkoxyamine) would suffer a severe thermal degradation at the elevated temperature above 140 °C.

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SUMMARY Mirabegron is a kind of β3 adrenergic receptor agonist which is an effective drug for the treatment of overactive bladder. In this research, a UPLC–MS/MS method is developed and validated for the study of mirabegron pharmacokinetic in rats. A protein precipitation method is applied for sample preparation with acetonitrile. m/z 397.3→379.6, m/z 326.4→121.0 for mirabegron, tolterodine (IS), respectively in the positive ion mode was performed for quantitation. The method is reliable and reproducible in our study (intra-day precision≤11.06%, inter-day precision≤11.43%) with concentration curves linear from 5 to 2500 ng/mL(R2>0.999). Stability studies demonstrated that mirabegron was stable under a variety of storage conditions. This method was successfully applied for determining mirabegron in rats after oral and intravenous administration.

With various learner factors identified, empathy have been assumed to affect foreign learning to the extent to which it may result in certain differences in learner's learning styles and strategies as well as the ultimate achievements. This paper reviews the research on the correlation between empathy and language learning .A small-scale survey about empathic state of non-English majors was carried out to indicate the effect of empathy on language learners' speaking proficiency. It aims to implicate that college language researchers could attempt empathy-related teaching techniques to create completely "native" classroom environment to help language learners improve their speaking performance in a most favorable affective state.

The Catcher in the Rye was written by famous American writer J.D.Salinger. This paper mainly analyzes the adolescent problems Holden Caulfield confronts on the journey from childhood to adulthood. These adolescent problems include Holden's protection of innocence, his disgust for the phoniness of the adult world, and his alienation from society. This paper concludes that these adolescent problems produce great impact on him. Holden behaves almost erratically and impulsively and has negative attitudes towards almost everything and everyone he meets.