On the slowness of phase boundary motion in one space dimension

We study the limiting behavior of the solution of with a Neumann boundary condition or an appropriate Dirichlet condition. The analysis is based on “energy methods”. We assume that the initial data has a “transition layer structure”, i.e., u^? ≈ ±+M 1 except near finitely many transition points. We show that, in the limit as ? → 0, the solution maintains its transition layer structure, and the transition points move slower than any power of ?.     

Study on Tonghaosu and Its Analogs： Isolation, Structure Identification and Synthesis of Antifeedant B-ring-homo-tonghaosu

The methanolic extract from a Chinese endemic Chrysanthemum plant, Dendranthema indicum var. aromaticum, was found to show high antifeeding activity against Pieris brassicae L., and by bioassay-guided separation, the active component, B-ring-homo-tonghaosu, 2-(2‘,4‘-hexadiynylidene)-1,6-dioxaspiro-[4,5]-dec-3-ene (2) was isolated. Its structure was elucidated by comparing its spectroscopic data with those of 2 reported in the literatures. Furthermore new convenient total synthesis methods of B-ring-homo-tonghaosu were also developed to confirm its structure and make its further application in crop protection available. In addition, extensive comparison of spectroscopic data showed that the structure of compound 21 reported in literature should be revised to 2.     

Synthesis of trimethylammoniumphenylthio-substituted phthalocyanines with different pattern of substitution

The base-catalyzed cyclotetramerization of 3-, 4- and 4,5-dimethylaminophenylthio phthalonitriles with zinc(II)acetate afforded 1(4),8(11),15(18),22(25)- and 2(3),9(10),16(17),23(24)-tetrasubstituted and 2,3,9,10,16,17,23,24-octasubstituted Zn(II)phthalocyanines, respectively. The statistical mixed condensation of the same phthalonitriles with 1,2-dicyanobenzene gave the corresponding mono- and disubstituted derivatives. Methylation of such products afforded a series of cationic Zn(II)phthalocyanines with different pattern of substitution, with potential use as photodynamic agents in microbial infections.