RESUMEN
The control of propagation direction or path of edge states is difficult when the chirality of the excitation source and the boundary structures are determined. Here, we studied a frequency-selective routing for elastic wave based on two types of topological phononic crystals (PnCs) with different symmetries. By constructing multiple types of interfaces between different PnCs structures with distinct valley topological phases, the valley edge states of elastic wave could be realized at different frequencies in the band gap. Meanwhile, based on the simulation of topological transport, it is found that the routing path of elastic waves valley edge states highly depends on the operating frequency and the inputting port of the excitation source. By varying the excitation frequency, the transport path can be switched. The results provide a paradigm for the control of elastic wave propagation paths that could be employed for designing the frequency-dependent ultrasonic division devices.
RESUMEN
<p><b>OBJECTIVE</b>To reveal the genetic characteristics of GII.12 Norovirus strains isolating from stool samples of adults with diarrhea in Beijing during 2008-2009.</p><p><b>METHODS</b>RdRp, ORF2, ORF3 and ORF1/ORF2 overlap region were respectively amplified by primers using RT-PCR. The products were purified, cloned, sequenced and then aligned, phylogenetic and recombinant analyzed by softwares of DNAStar, MEGA and SimPlot.</p><p><b>RESULTS</b>According to the phylogenetic analysis, 11 strains belonged to G II.g in the RdRp region,while GII.12 in the ORF2 and ORF3. SimPlot analysis further confirmed the 11 strains were recombinant strains ( G II.g [RdRp]/G II.12 [capsid]).</p><p><b>CONCLUSION</b>G II.12 Norovirus prevailing in Beijing and other regions of the world belonged to the same strain, and we identified the genetic characteristics of G II.12 Norovirus in Beijing.</p>