We observed reptation of single DNA molecules in fused silica nanoslits of sub-30 nm height. The reptation behavior and the effect of confinement are quantitatively characterized using orientation correlation and transverse fluctuation analysis. We s
how tube-like polymer motion arises for a tense polymer under strong quasi-2D confinement and interaction with surface- passivating polyvinylpyrrolidone (PVP) molecules in nanoslits, while etching- induced device surface roughness, chip bonding materials and DNA-intercalated dye-surface interaction, play minor roles. These findings have strong implications for the effect of surface modification in nanofluidic systems with potential applications for single molecule DNA analysis.
To alleviate traffic congestion, a variety of route guidance strategies has been proposed for intelligent transportation systems. A number of the strategies are proposed and investigated on a symmetric two-route traffic system over the past decade. T
o evaluate the strategies in a more general scenario, this paper conducts eight prevalent strategies on a asymmetric two-route traffic network with different slowdown behaviors on alternative routes. The results show that only mean velocity feedback strategy is able to equalize travel time, i.e., approximate user optimality; while the others fail due to incapability of establishing relations between the feedback parameters and travel time. The paper helps better understand these strategies, and suggests mean velocity feedback strategy if the authority intends to achieve user optimality.
We present an improved calculation on the pionic twist-3 distribution amplitudes $phi^{pi}_{p}$ and $phi^{pi}_{sigma}$, which are studied within the QCD sum rules. By adding all the uncertainties in quadrature, it is found that $<xi^2_p>=0.248^{+0.07
6}_{-0.052}$, $<xi^4_p>=0.262^{+0.080}_{-0.055}$, $<xi^2_sigma>=0.102^{+0.035}_{-0.025}$ and $<xi^4_sigma>=0.094^{+0.028}_{-0.020}$. Furthermore, with the help of these moments, we construct a model for the twist-3 wave functions $psi^{pi}_{p,sigma}(x,mathbf{k}_bot)$, which have better end-point behavior and are helpful for perturbative QCD approach. The obtained twist-3 distribution amplitudes are adopted to calculate the $Btopi$ transition form factor $f^+_{Bpi}$ within the QCD light-cone sum rules up to next-to-leading order. By suitable choice of the parameters, we obtain a consistent $f^+_{Bpi}$ with those obtained in the literature.
Using the first-principles density-functional theory plan-wave pseudopotential method, we investigate the structure and magnetism in 25% Mn substitutive and interstitial doped monoclinic, tetragonal and cubic ZrO2 systematically. Our studies show tha
t the introduction of Mn impurities into ZrO2 not only stabilizes the high temperature phase, but also endows ZrO2 with magnetism. Based on the simple crystal field theory (CFT), we discuss the origination of magnetism in Mn doped ZrO2. Moreover, we discuss the effect of electron donor on magnetic semiconductors, and the possibility as electronic structure modulator.
The magnetism in 12.5% and 25% Mn delta-doped cubic GaN has been investigated using the density-functional theory calculations. The results show that the single-layer delta-doping and half-delta-doping structures show robust ground state half-metalli
c ferromagnetism (HMF), and the double-layer delta-doping structure shows robust ground state antiferromagnetism (AFM) with large spin-flip energy of 479.0 meV per Mn-Mn pair. The delta-doping structures show enhanced two-dimensional magnetism. We discuss the origin of the HMF using a simple crystal field model. Finally, we discuss the antiferromagnet/ferromagnet heterostructure based on Mn doped GaN.
We study the electronic structure and magnetism of 25% Mn substituted cubic Zirconia (ZrO2) with several homogeneous and heterogeneous doping profiles using density-functional theory calculations. We find that all doping profiles show half-metallic f
erromagnetism (HMF), and delta-doping is most energy favorable while homogeneous doping has largest ferromagnetic stabilization energy. Using crystal field theory, we discuss the formation scheme of HMF. Finally, we speculate the potential spintronics applications for Mn doped ZrO2, especially as spin direction controllment.
