Molecular Dynamics Simulation of Strong Shock Waves Propagating in Dense Deuterium With the Effect of Excited Electrons

We present a molecular dynamics simulation of shock waves propagating in dense deuterium with the electron force field method [J. T. Su and W. A. Goddard, Phys. Rev. Lett. 99, 185003 (2007)], which explicitly takes the excitation of electrons into consideration. Non-equilibrium features associated with the excitation of electrons are systematically investigated. We show that chemical bonds in D$_2$ molecules lead to a more complicated shock wave structure near the shock front, compared with the results of classical molecular dynamics simulation. Charge separation can bring about accumulation of net charges on the large scale, instead of the formation of a localized dipole layer, which might cause extra energy for the shock wave to propagate. In addition, the simulations also display that molecular dissociation at the shock front is the major factor corresponding to the "bump" structure in the principal Hugoniot. These results could help to build a more realistic picture of shock wave propagation in fuel materials commonly used in the inertial confinement fusion

Self-assembly of noble metal nanoparticles into sub-100 nm colloidosomes with collective optical and catalytic properties.

Self-assembly at the nanoscale represents a powerful tool for creating materials with new structures and intriguing collective properties. Here, we report a novel strategy to synthesize nanoscale colloidosomes of noble metals by assembling primary metal nanoparticles at the interface of emulsion droplets formed by their capping agent. This strategy produces noble metal colloidosomes of unprecedentedly small sizes (<100 nm) in high yield and uniformity, which is highly desirable for practical applications. In addition, it enables the high tunability of the composition, producing a diversity of monometallic and bimetallic alloy colloidosomes. The colloidosomes exhibit interesting collective properties that are different from those of individual colloidal nanoparticles. Specifically, we demonstrate Au colloidosomes with well-controlled interparticle plasmon coupling and Au-Pd alloy colloidosomes with superior electrocatalytic performance, both thanks to the special structural features that arise from the assembly. We believe this strategy provides a general platform for producing a rich class of miniature colloidosomes that may have fascinating collective properties for a broad range of applications

Transmission resonance in a composite plasmonic structure

The design, fabrication, and optical properties of a composite plasmonic structure, a two-dimentional array of split-ring resonators inserted into periodic square holes of a metal film, have been reported. A new type of transmission resonance, which makes a significant difference from the conventional peaks, has been suggested both theoretically and experimentally. To understand this effect, a mechanism of ring- resonance induced dipole emission is proposed.Comment: 14 pages, 4 figure

Treating the Expansive Soil Subgrade on the Goaf of Middle-Shallow Layer by Dynamic Compaction With Geogrid Reinforcement

Middle-shallow layer goaf left after the excavation of small coal mines in expansive soil areas always brings much trouble to expressway construction, the section of K21 +400~K22 +550 of Nanning outer ring expressway under construction faces such a situation. Based on the grasp of geological condition of the goaf, related national technical specifications and existing technical research about treatment, the dynamic compaction with geogird reinforcement method is applied to settle the roadbed with a good result showed in the field testing. This paper introduces the geological condition and stability evaluation of the goaf, and emphatically presents the technical note, construction procedure, quality inspection of the dynamic compaction with geogird reinforcement and the filling method of the upper expansive soil subgrade, which can offer a reference for the similar treatment projects in other expansive soil areas

4-Tosyl-1-oxa-4-aza­spiro­[4.5]deca-6,9-dien-8-one

In the mol­ecule of the title compound, C15H15NO4S, the two six-membered rings are almost parallel to each other [dihedral angle = 1.87 (9)°] and perpendicular to the mean plane through the five-membered ring [dihedral angles of 89.98 (10) and 89.04 (10)°]. The crystal structure is stabilized by inter­molecular C—H⋯O hydrogen-bonding inter­actions

How and When Review Length and Emotional Intensity Influence Review Helpfulness: Empirical Evidence from Epinions.com

Although longer reviews are generally considered more helpful, no research has investigated whether “the more the better” also applies to the expression of emotions. This paper explores the distinct effects of review length and emotional intensity. We propose that, in contrast to review length, the intensity of emotions has a negative effect on review helpfulness, and that this effect only applies to positive emotions. Additionally, drawing on elaboration likelihood model and the literature on the social functions of emotions, we predict that the respective effects of review length and emotional intensity are moderated by reviewer trustworthiness and the difficulty of reading review content. To test these hypotheses, we collected a rich data set from Epinions.com - a leading provider of consumer reviews. Our findings reveal the importance of taking the intensity of emotions into consideration when evaluating review helpfulness, and the results carry important practical implications