Plasmonic bandgap in random media

We present a dispersion theory of the surface plasmon polaritons (SPP) in random metal-dielectric nanocomposite (MDN) consisting of bulk metal embedded with dielectric inclusions. We demonstrate that embedding of dielectric nanoparticles in metal results in the formation of the plasmonic bandgap due to strong coupling of the SPP at the metal-vacuum interface and surface plasmons localized at the surface of nanoinclusions. Our results show that MDN can replace metals in various plasmonic devices, which properties can be tuned in a wide spectral range. Being compatible with waveguides and other photonic structures, MDN offers high flexibility in the plasmonic system design.     

Length of the Pre-Detonation Region in Plastic-Bonded HMX Samples as a Function of the Velocity and Size of a Spherical Impactor

Combustion, Explosion, and Shock Waves - Experimental results on the parameters of detonation process formation in plastic-bonded HMX as functions of the velocity and size of spherical impactors...     

Let the light be a guide: Chromophore communication in metal-organic frameworks

The photonic characteristics of chromophore-containing metal-organic frameworks(MOFs)have led to extensive photophysical studies in an effort to capitalize on the potency of precisely controlled chromophore ensembles.Several examples have laid the foundation that demonstrates how photophysical properties of chromophores can be manipulated by tuning their communications(interactions)through integration within a MOF matrix.The main focus of this review is on harnessing the versatile MOF platform to accentuate the photophysical properties of integrated chromophores.In particular,this review will highlight chromophore dynamics that enhance,alter,or tune the photoluminescence response of single-and multi-chromophore-containing scaffolds,as well as alignment-guided anisotropic fluorescence.Building upon this groundwork,utilization of a hybrid crystalline motif can induce preferential orientation of chromophores resulting in enhanced communication and tailored behavior compared to randomly oriented emissive molecules.Moreover,frameworks that produce upconverted emission via sensitized triplet-triplet annihilation(sTTA),excited-state absorption(ESA),energy transfer upconversion(ETU),multi-photon absorption(MPA),or second-harmonic generation(SHG)can invoke dynamic control of material properties using photochromic linkers and will be discussed herein with a focus on the effects of chromophore alignment.Integration within a framework is a vehicle tofuse chromophores into solid-state platforms,opening an avenue for chromophore utilization in applications such as portable electronics that require solids or thin films.For those reasons,the design of chromophore-containing MOFs with desirable properties that rely on the alignment and communication of hundreds of chromophores within a single platform is a pressing demand for the development of futuristic technologies.     

Effect of preliminary mechanical damage and porosity of explosive on the initiation conditions and explosion parameters in low-velocity impact

This paper presents the results of experimental studies of the effect of the damage and initial porosity of desensitized HMX samples on the limiting initiation conditions and explosion parameters under impact of steel spherical projectiles weighing 2–100 g. It is shown that preliminary mechanical damage to explosive samples and reducing their initial density lead to qualitatively the same result—an increase in the limiting impactor velocity initiating explosive transformation. Data are obtained on the damage structure of the samples in the absence of initiation and on the dependence of the physicomechanical properties of samples on their density.