Zhongyang Li

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A pot experiment in six open-top chambers with two levels of CO(2) and two multi-metal contaminated soils was conducted to investigate combined effects of elevated CO(2) levels and metals (Cu and Cd) on rice. Elevated CO(2) significantly increased the total dry weight biomass of six Chinese rice by 20-108 and 32-142% for low and high levels of contaminated(More)
Coupling between superradiant and subradiant mode resonators in a metamaterial unit cell plays an important role in observing the sharp transparency peak due to destructive interference between the resonators. This effect is enhanced as the resonators are brought closer to each other in a conventional planar arrangement. We present a novel coupling scheme(More)
Nanostructured photonic materials enable control and manipulation of light at subwavelength scales and exhibit unique optical functionalities. In particular, plasmonic materials and metamaterials have been widely utilized to achieve spectral transmission, reflection, and absorption filters based on localized or delocalized resonances arising from the(More)
Ultrathin metasurfaces have recently emerged as promising materials that have huge potential to enable novel, flat optical components, and surface-confined, miniature photonic devices. Metasurfaces offer new degrees of freedom in molding the optical wavefronts by introducing abrupt and drastic changes in the amplitude, phase, and/or polarization of(More)
Nanostructured metals have received a significant amount of attention in recent years due to their exciting plasmonic and photonic properties enabling strong field localization, light concentration, and strong absorption and scattering at their resonance frequencies. Resonant plasmonic and metamaterial absorbers are of particular interest for applications(More)
The Fisher transformation acts on cubic graphs by replacing each vertex by a triangle. We explore the action of the Fisher transformation on the set of self-avoiding walks of a cubic graph. Iteration of the transformation yields a sequence of graphs with common critical exponents, and with connective constants converging geometrically to the golden mean. We(More)
Plasmon lasers support cavity structures with sizes below that of the diffraction limit. However, most plasmon-based lasers show bidirectional lasing emission or emission with limited far-field directionality and large radiative losses. Here, we report unidirectional lasing from ultrasmooth, template-stripped two-dimensional (2D) plasmonic crystals.(More)
The control of light−material interactions at the nanoscale requires optical elements with sizes much smaller than the wavelength of light. Plasmonic nanostructures and optical metamaterials enable drastic control and manipulation of light at such small scales. However it is quite challenging to further reduce the size of resonant elements using(More)
The connective constant μ(G) of a graph G is the asymptotic growth rate of the number of self-avoiding walks on G from a given starting vertex. We survey three aspects of the dependence of the connective constant on the underlying graph G. Firstly, when G is cubic, we study the effect on μ(G) of the Fisher transformation (that is, the replacement of(More)