Blow up solutions to a viscoelastic fluid system and a coupled Navier-Stokes/Phase-Field system in R^2

We find explicit solutions to both the Oldroyd-B model with infinite Weissenberg number and the coupled Navier-Stokes/Phase-Field system. The solutions blow up in finite time.Comment: 5 page

Poly[bis­[μ-1,4-bis­(imidazol-1-yl)butane]dicyanato­cadmium(II)]

The coordination geometry of the CdII atom in the title complex, [Cd(NCO)2(C10H14N4)2]n or [Cd(NCO)2(bimb)2]n, where bimb is 1,4-bis­(imidazol-1-yl)butane, is distorted octa­hedral with the CdII atom located on an inversion center and connected to four N atoms from the imidazole units of four symmetry-related bimb ligands and two O atoms from two symmetry-related NCO− ligands. The CdII atoms are bridged by four bimb ligands, forming a two-dimensional (4,4) network

An efficient DNA isolation method for tropical plants

Due to interfering components such as polysacharrides, polyphenols, etc, DNA isolation from tropical plants had been challenging. We developed a safe, universal and efficient DNA extraction method, which yielded high-quality DNA from 10 tropical plants including cassava, rubber tree, banana, etc. In the extraction buffer, 2 M NaCl was used to provide a high ionic strength reaction environment, ethylenediaminetetraacetic acid (EDTA), lauroyl sarcosine (LSS) and cetyl trimethyl ammonium bromide (CTAB) could inhibit DNase activity effectively, polyvinylpolypyrrolidone (PVPP) produced a deoxidized reaction environment, and borax enhanced the precipitation of interfering compounds. Ordinary reagents like β-mercaptoethanol, chloroform and phenol were unnecessary in this protocol, which made it safe and friendly to use. PCR and EcoR I enzyme restriction digestion results show that the obtained DNA is good enough for downstream analysis. In conclusion, this protocol is expected to be a preferable DNA extraction protocol for tropical plants.Keywords: DNA extraction, tropical plants, cetyl trimethyl ammonium bromide (CTAB)African Journal of Biotechnology Vol. 12(19), pp. 2727-273

Analogue to multiple electromagnetically induced transparency in all-optical drop-filter systems

We theoretically study a parallel optical configuration which includes N periodically coupled whispering-gallery-mode resonators. The model shows an obvious effect which has a direct analogy with the phenomenon of multiple electromagnetically induced transparency in quantum systems. The numerical simulations illuminate that the frequency transparency windows are sharp and highly transparent. We also briefly discuss the experimental feasibility of the current scheme in two practical systems, microrings and microdisks.Comment: 4 pages, 4 figure

Nature of the X(6900)X(6900) in partial wave decomposition of J/ψJ/ψJ/\psi J/\psi scattering

In this letter, we perform partial wave decomposition on coupled channel scattering amplitudes, $J/\psi J/\psi$-$J/\psi \psi(2S)$-$J/\psi \psi(3770)$, to study the resonance appears in these processes. Effective Lagrangians are used to describe the interactions of four charmed vector mesons, and the scattering amplitudes are calculated up to the next-to-leading order. Partial wave projections are performed, and unitarization is implemented by Pad\'e approximation. Then we fit the amplitudes to the $J/\psi J/\psi$ invariant mass spectra measured by LHCb and determine the unknown couplings. The pole parameters of the $X(6900)$ are extracted as $M=6861.0^{+6.3}_{-8.8}$~MeV and $\Gamma=129.0^{+5.6}_{-3.4}$~MeV. Our analysis implies that its quantum number prefers to be $0^{++}$. The pole counting rule and phase shifts show that it is a normal Breit-Wigner resonance and hence should be a compact tetraquark.Comment: 6 pages, 4 figure

Dependence of the decoherence of polarization states in phase-damping channels on the frequency spectrum envelope of photons

We consider the decoherence of photons suffering in phase-damping channels. By exploring the evolutions of single-photon polarization states and two-photon polarization-entangled states, we find that different frequency spectrum envelopes of photons induce different decoherence processes. A white frequency spectrum can lead the decoherence to an ideal Markovian process. Some color frequency spectrums can induce asymptotical decoherence, while, some other color frequency spectrums can make coherence vanish periodically with variable revival amplitudes. These behaviors result from the non-Markovian effects on the decoherence process, which may give rise to a revival of coherence after complete decoherence.Comment: 7 pages, 4 figures, new results added, replaced by accepted versio