Anomalous effective medium approximation breakdown in deeply subwavelength all-dielectric photonic multilayers

We present a comprehensive analysis of the applicability of the effective medium approximation to deeply subwavelength (period ##IMG## [http://ift.tt/1FW5T5N] {$\leqslant \lambda /50)$} all-dielectric multilayer structures. We demonstrate that even though the dispersion relations for such multilayers differ from the effective medium prediction only slightly, there can be regimes when an actual multilayer stack exhibits significantly different properties compared to its homogenized model. In particular, reflection near the critical angle is shown to strongly depend on even very small period variations, as well as on the choice of the multilayer termination. We identify the geometries for which the influence of the subwavelength features is maximized and demonstrate that the difference between the reflectance from the actual multilayer and the effective medium prediction can be as great as 0.98. The results of this...

Andrei Andryieuski, Andrei V Lavrinenko and Sergei V Zhukovsky

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Carbon nanoelectrodes for single-cell probing

Carbon nanoelectrodes with tip diameters ranging from tens to hundreds of nanometers are fabricated by pyrolitic deposition of carbon films along the entire inner surfaces of pulled-glass pipettes. The pulled end of each glass pipette is then etched to expose a desired length (typically, a few micrometers) of carbon pipe. The carbon film provides an electrically conductive path from the nanoscopic carbon tip to the distal, macroscopic end of the pipette, bridging between the nanoscale tip and the macroscale handle, without a need for assembly. We used our nanoelectrodes to penetrate into individual cells and cell nuclei and measured the variations in the electrode impedance upon cell and nucleus penetration as well as the electrode impedance as a function of cell penetration depth. Theoretical predictions based on a simple circuit model were in good agreement with experimental data.

Sean E Anderson and Haim H Bau

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Molecular dynamics simulations of mechanical properties of monolayer MoS 2

Based on the benchmark created by the first principle calculations, the effectiveness of different empirical potential functions, including CVFF1, CVFF2, SW and REBO potentials, on describing the mechanical behavior of single layer MoS 2 (SLMoS 2 ) are evaluated. The mechanical properties including the elastic modulus E , Poisson’s ratio ν , nonlinear elastic modulus D , failure stress and ultimate strain are considered. It is found that under a small deformation, the REBO and CVFF2 potentials can provide an effective description of the elastic behavior of SLMoS 2 ; whereas under a large deformation, the SW potential gives a more accurate stress value and the CVFF2 potential can only predict the right value under biaxial tension. After modifying the cut-off distances in the REBO potential, the failure strain can be reasonably predicted by the REBO potential; whereas the failure stress will be overestimated by about 20–40% for biaxial ...

Si Xiong and Guoxin Cao

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Force reconstruction from tapping mode force microscopy experiments

Fast, accurate, and robust nanomechanical measurements are intensely studied in materials science, applied physics, and molecular biology. Amplitude modulation force microscopy (tapping mode) is the most established nanoscale characterization technique of surfaces for air and liquid environments. However, its quantitative capabilities lag behind its high spatial resolution and robustness. We develop a general method to transform the observables into quantitative force measurements. The force reconstruction algorithm has been deduced on the assumption that the observables (amplitude and phase shift) are slowly varying functions of the tip–surface separation. The accuracy and applicability of the method is validated by numerical simulations and experiments. The method is valid for liquid and air environments, small and large free amplitudes, compliant and rigid materials, and conservative and non-conservative forces.

Amir F Payam, Daniel Martin-Jimenez and Ricardo Garcia

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Desorption Kinetics and Activation Energy for Cobalt Octaethylporphyrin from Graphite at the Phenyloctane Solution–Graphite Interface: An STM Study

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5b01444

Ashish Bhattarai, Ursula Mazur and K. W. Hipps

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Chemisorbed Oxygen on the Au(321) Surface Alloyed with Silver: A First-Principles Investigation

The Journal of Physical Chemistry C

DOI: 10.1021/jp511884k

Lyudmila V. Moskaleva, Theodor Weiss, Thorsten Klüner and Marcus Bäumer

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Tuning the Electrical Transport Properties of Multilayered Molybdenum Disulfide Nanosheets by Intercalating Phosphorus

The Journal of Physical Chemistry C

DOI: 10.1021/jp5128018

Lijuan Ye, Shijian Chen, Wanjun Li, Mingyu Pi, Tianli Wu and Dingke Zhang

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Mesoporous Ge/GeO2/Carbon Lithium-Ion Battery Anodes with High Capacity and High Reversibility

ACS Nano

DOI: 10.1021/acsnano.5b00817

Jongkook Hwang, Changshin Jo, Min Gyu Kim, Jinyoung Chun, Eunho Lim, Seongseop Kim, Sanha Jeong, Youngsik Kim and Jinwoo Lee

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Intracellular Self-Assembly and Disassembly of 19F Nanoparticles Confer Respective “Off” and “On” 19F NMR/MRI Signals for Legumain Activity Detection in Zebrafish

ACS Nano

DOI: 10.1021/acsnano.5b00287

Yue Yuan, Shuchao Ge, Hongbin Sun, Xuejiao Dong, Hongxin Zhao, Linna An, Jia Zhang, Junfeng Wang, Bing Hu and Gaolin Liang

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Mechanism of the Delithiation/Lithiation Process in LiFe0.4Mn0.6PO4: in Situ and ex Situ Investigations on Long-Range and Local Structures

The Journal of Physical Chemistry C

DOI: 10.1021/jp513032r

Ilham Bezza, Maximilian Kaus, Ralf Heinzmann, Murat Yavuz, Michael Knapp, Stefan Mangold, Stephen Doyle, Clare P. Grey, Helmut Ehrenberg, Sylvio Indris and Ismael Saadoune

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Thermochromism, Franck–Condon Analysis and Interfacial Dynamics of a Donor–Acceptor Copolymer with a Low Band Gap

Chemistry of Materials

DOI: 10.1021/cm504655f

Matthew E. Reish, Gregory S. Huff, Wonho Lee, Mohammad Afsar Uddin, Alex J. Barker, Joseph K. Gallaher, Justin M. Hodgkiss, Han Young Woo and Keith C. Gordon

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Solution-Mediated Selective Nanosoldering of Carbon Nanotube Junctions for Improved Device Performance

ACS Nano

DOI: 10.1021/nn505552d

Jae-Won Do, Noel N. Chang, David Estrada, Feifei Lian, Hyeongyun Cha, Xiangyun J. Duan, Richard T. Haasch, Eric Pop, Gregory S. Girolami and Joseph W. Lyding

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Environmental Changes in MoTe2 Excitonic Dynamics by Defects-Activated Molecular Interaction

ACS Nano

DOI: 10.1021/acsnano.5b00985

Bin Chen, Hasan Sahin, Aslihan Suslu, Laura Ding, Mariana I. Bertoni, F. M. Peeters and Sefaattin Tongay

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Polythienylene–Vinylene Structure–Function Correlations Revealed from Resonance Raman Spectroscopy and Photocurrent Imaging

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5b02166

Jian Gao, Alan K. Thomas, Jianzhang Yang, Cody Aldaz, Guoshun Yang, Yang Qin and John K. Grey

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Influence of the Local Atom Configuration on a Hexagonal Skyrmion Lattice

Nano Letters

DOI: 10.1021/acs.nanolett.5b00506

Kirsten von Bergmann, Matthias Menzel, André Kubetzka and Roland Wiesendanger

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Computational Exploration of the Mechanism of the Hydrogenation Step of the Anthraquinone Process for Hydrogen Peroxide Production

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5b01325

Takashi Kamachi, Tatsunobu Ogata, Eiichirou Mori, Katsuhiro Iura, Norikazu Okuda, Masaki Nagata and Kazunari Yoshizawa

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Photosplitting of Water from Wide-Gap Cu(In,Ga)S2 Thin Films Modified with a CdS Layer and Pt Nanoparticles for a High-Onset-Potential Photocathode

The Journal of Physical Chemistry C

DOI: 10.1021/acs.jpcc.5b02068

Wilman Septina, Gunawan, Shigeru Ikeda, Takashi Harada, Masanobu Higashi, Ryu Abe and Michio Matsumura

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Real-Time Monitoring of ATP-Responsive Drug Release Using Mesoporous-Silica-Coated Multicolor Upconversion Nanoparticles

ACS Nano

DOI: 10.1021/acsnano.5b00641

Jinping Lai, Birju P. Shah, Yixiao Zhang, Letao Yang and Ki-Bum Lee

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Local Conformational Switching of Supramolecular Networks at the Solid/Liquid Interface

ACS Nano

DOI: 10.1021/acsnano.5b01658

Fernando P. Cometto, Klaus Kern and Magalí Lingenfelder

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Versatile Conjugated Polymer Nanoparticles for High-Resolution O2 Imaging in Cells and 3D Tissue Models

ACS Nano

DOI: 10.1021/acsnano.5b00771

Ruslan I. Dmitriev, Sergey M. Borisov, Heiko Düssmann, Shiwen Sun, Bernhard J. Müller, Jochen Prehn, Vladimir P. Baklaushev, Ingo Klimant and Dmitri B. Papkovsky

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