Electronic Structure of Twisted Bilayers of Graphene/MoS₂ and MoS₂/MoS₂

Vertically stacked two-dimensional multilayer structures have become a promising prototype for functionalized nanodevices due to their wide range of tunable properties. In this paper we performed first-principles calculations to study the electronic structure of nontwisted and twisted bilayers of hybrid graphene/MoS₂ (Gr/MoS₂) and MoS₂/MoS₂. Both twisted bilayers of Gr/MoS₂ and MoS₂/MoS₂ show significant differences in band structures from the nontwisted ones with the appearance of the crossover between direct and indirect band gap and gap variation. More interestingly, the band structures of twisted Gr/MoS₂ with different rotation angles are very different from each other, while those of MoS₂/MoS₂ are very similar. The variation of band structure with rotation angle in Gr/MoS₂ is, indeed, originated from the misorientation-induced lattice strain and the sensitive band-strain dependence of MoS₂

Visualization 1: Graphics processing unit–assisted real-time three-dimensional measurement using speckle-embedded fringe

Measurement result of a shaking paper Originally published in Applied Optics on 01 August 2015 (ao-54-22-6865

Visualization 1: Adaptive step-size strategy for noise-robust Fourier ptychographic microscopy

The evolution of the amplitude reconstructions of an USAF resolution target with an adaptive step-size. Originally published in Optics Express on 05 September 2016 (oe-24-18-20724

Staged Self-Assembly of Colloidal Metastructures

We demonstrate sequential assembly of chemically patchy colloids such that their valence differs from stage to stage to produce hierarchical structures. For proof of concept, we employ ACB triblock spheres suspended in water, with the C middle band electrostatically repulsive. In the first assembly stage, only A–A hydrophobic attraction contributes, and discrete clusters form. They can be stored, but subsequently activated to allow B–B attractions, leading to higher-order assembly of clusters with one another. The growth dynamics, observed at a single particle level by fluorescence optical microscopy, obey the kinetics of stepwise polymerization, forming chains, pores, and networks. Between linked clusters, we identify three possible bond geometries, linear, triangular, and square, by an argument that is generalizable to other patchy colloid systems. This staged assembly strategy offers a promising route to fabricate colloidal assemblies bearing multiple levels of structural and functional complexity

Organic Stealth Nanoparticles for Highly Effective <i>in Vivo</i> Near-Infrared Photothermal Therapy of Cancer

In recent years, a wide range of near-infrared (NIR) light absorbing nanomaterials, mostly inorganic ones, have been developed for photothermal therapy (PTT) of cancer. In this work, we develop a novel organic PTT agent based on poly-(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS), a conductive polymer mixture with strong NIR absorbance, for <i>in vivo</i> photothermal treatment of cancer. After being layer-by-layer coated with charged polymers and then conjugated with branched polyethylene glycol (PEG), the obtained PEDOT:PSS-PEG nanoparticles are highly stable in the physiological environment and exhibit a stealth-like behavior after intravenous injection with a long blood circulation half-life. As a result, an extremely high <i>in vivo</i> tumor uptake of PEDOT:PSS-PEG attributed to the tumor-enhanced permeability and retention effect is observed. We further use PEDOT:PSS-PEG as a PTT agent for <i>in vivo</i> cancer treatment and realize excellent therapeutic efficacy in a mouse tumor model under NIR light irradiation at a low laser power density. Comprehensive blood tests and careful histological examination reveal no apparent toxicity of PEDOT:PSS-PEG to mice at our treated dose within 40 days. To our best knowledge, this work is the first to use systemically administrated conductive polymer nanoparticles for highly effective <i>in vivo</i> PTT treatment in animals and encourages further explorations of those organic nanomaterials for cancer theranostic applications

Spatial scaling of soil salinity indices along a temporal coastal reclamation area transect in China using wavelet analysis

<p>High spatial variability of soil salinity in coastal reclamation regions makes it difficult to obtain accurate scale-dependent information. The objectives of this study were to describe the spatial patterns of saline-sodic soil properties (using soil pH, electrical conductivity (EC_1:5) and sodium ion content (<i>SIC</i>) as indicators) and to gain knowledge of the scaling relationships between those variables. The soil pH, EC_1:5 and <i>SIC</i> data were measured at intervals of 285 m along a 13,965-m temporal transect in a coastal region of China. The spatial variability of soil pH was weak but it was strong for soil EC_1:5 and <i>SIC</i> at the measurement scale. There was a significant positive correlation between soil EC_1:5 and <i>SIC</i>, while correlations between soil pH and either EC_1:5 or <i>SIC</i> were weak and negative. For each saline-sodic soil parameter, the variability changed with the decomposition scales. The high-variance area at the larger scales (≥570 m) occupied less than 10% of the total area in the local wavelet spectrum, which meant that the spatial variations of the salinity indicators were insignificant at these scales. For local wavelet coherency, at a scale of 1500–2800 m and a sampling distance of 0–4500 m, the covariance was statistically significant between any two of the saline-sodic soil parameters.</p

Media 3: High-speed transport-of-intensity phase microscopy with an electrically tunable lens

Originally published in Optics Express on 07 October 2013 (oe-21-20-24060

MOESM1 of Microbial community compositions in different functional zones of Carrousel oxidation ditch system for domestic wastewater treatment

Additional file 1: Table S1. Characteristics of the six representative full-scale WWTPs. Table S2: Raw and trimmed reads, Good’s coverage, Chao1, ACE, Shannon, Simpson, and plus numbers of OTUs of the activated sludge samples

Media 1: Noninterferometric single-shot quantitative phase microscopy

Originally published in Optics Letters on 15 September 2013 (ol-38-18-3538

Media 3: Transport-of-intensity phase imaging using Savitzky-Golay differentiation filter - theory and applications

Originally published in Optics Express on 11 March 2013 (oe-21-5-5346