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Zhang J.,CAS Hefei Institutes of Physical Science | Zhang L.,CAS Hefei Institutes of Physical Science
Advances in Optics and Photonics | Year: 2012

Surface plasmons (SPs) are electromagnetic excitations existing at the interface between a metal and a dielectric material. Control and manipulation of light based on SPs at the nanometer scale offers significant advantages in nanophotonic devices with very small elements, since the peculiar properties of SPs can be tailored by construction of nanostructures with various interfaces between metals and dielectric materials. Recent progress in nanostructures for SPs is reviewed. Resonance frequencies or wavelengths of SPs can be tuned by design of metal nanostructures, such as nanoparticles, nanorods, nanowires, nanosheets, and nanodisks. Moreover, SP resonance modes can also be tuned by control of the shapes and sizes of nanostructures, where the resonance modes include longitudinal and transversal resonances, dipolar and multipolar resonances, and Fano resonances. Based on SP coupling for metal nanostructures, metal-semiconductor nanostructures, metal-dielectric nanostructures, and metal-polymer nanostructures, propagating and guiding of SP can be achieved through the metal nanostructures and the hybrid structures. Additionally, metal nanostructures exhibit remarkable field enhancement effects (e.g., local near-field enhancement, and optical transmission enhancement) due to SP coupling. Furthermore, SP nanostructures perform unique focusing and imaging characteristics at the nanometer scale beyond the diffraction limit. Tailoring SPs by control of the nanostructures is expected to be used for design and development of high-performance optical components and circuits, which offer both potential and challenges for new generations of nanophotonic devices. © 2012 Optical Society of America.

Hu C.,CAS Hefei Institutes of Physical Science
Plasma Science and Technology | Year: 2015

As one of the most effective methods for plasma heating, a neutral beam injector (NBI) achieved plasma heating and current driving for the first time in EAST 2014 experimental campaign. According to the research plan of the EAST physics experiment, the first NBI (EAST-NBI-1) has been built and become operational in 2014. In this article, the latest experiment results of EAST-NBI-1 are reported as follows: (1) EAST achieves H-mode plasma in the case of NBI heating alone, (2) EAST achieves 22 s long pulse stable H-mode plasma in the case of simultaneous NBI and lower hybrid wave (LHW) heating. The measurement data show that the loop voltage decreased and the plasma stored energy increased obviously. The results indicate that EAST-NBI-1 has achieved plasma heating and current driving, and thus lays a foundation for the construction of EAST-NBI-2, which will be built in a few months this year. © 2015, Institute of Physics Publishing. All rights reserved.

Hu L.,CAS Hefei Institutes of Physical Science | Chen Q.,CAS Hefei Institutes of Physical Science | Chen Q.,Hefei University of Technology
Nanoscale | Year: 2014

Lithium-ion batteries (LIBs), owing to their high energy density, light weight, and long cycle life, have shown considerable promise for storage devices. The successful utilization of LIBs depends strongly on the preparation of nanomaterials with outstanding lithium storage properties. Recent progress has demonstrated that hollow/porous nanostructured oxides are very attractive candidates for LIBs anodes due to their high storage capacities. Here, we aim to provide an overview of nanoscale metal-organic frameworks (NMOFs)-templated synthesis of hollow/porous nanostructured oxides and their LIBs applications. By choosing some typical NMOFs as examples, we present a comprehensive summary of synthetic procedures for nanostructured oxides, such as binary, ternary and composite oxides. Hollow/porous structures are readily obtained due to volume loss and release of internally generated gas molecules during the calcination of NMOFs in air. Interestingly, the NMOFs-derived hollow/porous structures possess several special features: pores generated from gas molecules release will connect to each other, which are distinct from "dead pores"; pore size often appears to be <10 nm; in terms of surface chemistry, the pore surface is hydrophobic. These structural features are believed to be the most critical factors that determine LIBs' performance. Indeed, it has been shown that these NMOFs-derived hollow/porous oxides exhibit excellent electrochemical performance as anode materials for LIBs, including high storage capacity, good cycle stability, and so on. For example, a high charge capacity of 1465 mA h g -1 at a rate of 300 mA g-1 was observed after 50 cycles for NMOFs-derived Co3O4 porous nanocages, which corresponds to 94.09% of the initial capacity (1557 mA h g-1), indicating excellent stability. The capacity of NMOFs-derived Co 3O4 is higher than that of other Co3O 4 nanostructures obtained by a conventional two-step route, including nanosheets (1450 mA h g-1 at 50 mA g-1), nanobelts (1400 mA h g-1 at 40 mA g-1) and nanoflowers (694 mA h g -1 at 100 mA g-1). The capacity is also better than Co3O4 octahedra obtained by a one-step hydrothermal method (946 mA h g-1 at 100 mA g-1). In this review, we will summarize the recent research advances on NMOFs-derived hollow/porous oxides as LIBs anodes. The enhanced lithium storage properties have been discussed in relation to their special structural parameters. Moreover, remarks on the current challenges and perspectives for future NMOFs applications are proposed. Through this systematic review, we aim to stress the importance of NMOFs templates for the fabrication of hollow/porous functional materials that would result in improved physicochemical properties and provide insights to guide future research for LIBs applications. © 2013 The Royal Society of Chemistry.

Wu Z.,CAS Hefei Institutes of Physical Science
Angewandte Chemie - International Edition | Year: 2012

Unexpected: Anti-galvanic reduction (AGR), that is, metal ions are reduced by more-noble metals, was found in small thiolated gold (see figure) and silver nanoparticles! These findings are not only unexpected considering the classic galvanic theory, but also provide a facile and mild method to make alloys on the nanoscale or tune the compositions, structures, and properties of nanostructures that are otherwise difficult to obtain. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Li Y.,CAS Hefei Institutes of Physical Science | Duan G.,CAS Hefei Institutes of Physical Science | Liu G.,CAS Hefei Institutes of Physical Science | Cai W.,CAS Hefei Institutes of Physical Science
Chemical Society Reviews | Year: 2013

It has been proven that the use of colloidal templates is a facile, flexible strategy to create the periodic micro/nanostructured arrays in comparison with photolithography, electron beam lithography etc. Utilizing colloidal monolayers as templates or masks, different periodic micro/nanostructured arrays including nanoparticle arrays, pore arrays, nanoring arrays and nanorod/nanotube arrays can be fabricated by chemical and physical processes. Chemical routes, including direct solution/sol dipping strategy, wet chemical etching, electrodeposition, electrophoretic deposition etc. have advantages of simple operation and low costs. However, they have some disadvantages of impurities on surface of arrays due to incomplete decomposition of precursors, residue of surfactants in self-assembling or electrochemical deposition. More importantly, it is quite difficult to achieve very uniform morphology of micro/nanostructure arrays on a large-area by the above routes. Whereas another method, a physical route (for instance: reactive ion etching, pulsed laser deposition, thermal evaporation deposition, atomic layer deposition, sputtering deposition), combining with colloidal monolayer template can well resolve these problems. In this review, we focus on introducing the recent progress in creating micro/nanostructured arrays based on colloidal templates with physical routes. The parameters of the microstructure or nanostructure can be tuned by colloidal templates with different periodicity and experimental conditions of the physical processes. The applications of micro/nanostructured arrays with controllable morphology and arrangement parameters in self-cleaning surfaces, enhanced catalytic properties, field emitters etc. are also presented in the following sections. © 2013 The Royal Society of Chemistry.

Hu C.,CAS Hefei Institutes of Physical Science
Plasma Science and Technology | Year: 2012

The neutral beam injection (NBI) system is one of the most important auxiliary plasma heating and current driving methods for fusion device. A high power ion beam of 3 MW with 80 keV beam energy in 0.5 s beam duration and a long pulse ion beam of 4 s with 50 keV beam energy ion beam extraction were achieved on the EAST neutral beam injector on the test-stand. The preliminary results show that the EAST-NBI system was developed successfully on schedule.

Hu C.,CAS Hefei Institutes of Physical Science
Plasma Science and Technology | Year: 2012

Neutral beam injection (NBI) system with two neutral beam injections will be constructed on the Experimental Advanced Superconducting Tokamak (EAST) in two stages for high power auxiliary plasmas heating and non-inductive current drive. Each NBI can deliver 2∼4 MW beam power with 50∼80 keV beam energy in 10∼100 s pulse length. Each elements of the NBI system are presented in this contribution.

Welding wire for gas protective welding of reduced activation ferritic/martensitic steel and the manufacturing method, chemical components (weight percentage, wt %): C: 0.10.15, Cr: 8.09.0, W: 1.01.6, V: 0.150.25, Ta: 0.100.17, Mn: 0.500.70, Si: 00.05, N: 00.02, O, Ni, Cu, Al, and Co: 00.01 respectively, P, S, Ag, Mo, and Nb: 00.005 respectively, and balance of Fe. The welding wire has Cr equivalent weight of less than 11, Ni equivalent weight of greater than 3.5. It is manufactured with a wire rod through multi-pass drawing. The rod is subject to annealing heat treatment, tempering treatment performed between the passes of drawing. The annealing process is: the rod is at 9401020 for 2060 minutes, and the n cooled to below 650 C. at rate of less than 45 C./hour, air-cooled to room temperature. The tempering process is: the rod is at 760820 for 0.52 hours. It reduces forming of ferrites in welded joints.

CAS Hefei Institutes of Physical Science | Date: 2014-05-09

A type of High Magnetic Field Assisted PLD System consisting of pulsed laser and PLD cylindrical vacuum chamber inclusive of double-layer clip-sheath cylindrical chamber with water cooling located in the bore hole of superconducting magnet is disclosed. A flange plate in one side of the double-layer clip sheath is equipped with substrate heating table or laser heating table and rotating mechanism; the flange plate in another side is equipped with target components and moving/rotating mechanism. Either the substrate heating table or laser heating table is located in the center area of magnetic field of the superconducting magnet. A PLD (pulsed laser deposition) cylindrical vacuum chamber is located in the slide rail. A sealed laser leading-in chamber and a vacuum-sealed video-unit leading-in chamber is installed on the flange plate in one side of double-layer clip sheath cylindrical chamber.

Zhang L.,CAS Hefei Institutes of Physical Science | Fang M.,CAS Hefei Institutes of Physical Science
Nano Today | Year: 2010

Clean environment is essential to human health. The world is facing formidable challenges in meeting rising requirement to clean environment. Recently, persistent organic pollutants (POPs), heavy metals, etc. pollutants in water and soil are the key factors which make the environment worse. Even trace pollutants can enter human body and do harm to human health. Trace detection and treatment of these pollutants become an eagerly solved problem. Nanomaterials and nanotechnology provide a powerful method for detection and treatment of trace pollutants in the environment. This article reviews the recent progress of detection and treatment of POPs and heavy metal by using nanomaterials and analytical nanotechnology. And the application of nanomaterials and nanotechnology through enhancement of Raman scattering, surface plasmon resonance, fluorescent detection and electrochemical detection were described. We highlight recent advances on the development of novel nanomaterials and nanostructures and processes for treatment of POPs and heavy metals in water and soil. We also discussed the mechanisms of POPs degradation and heavy metal treatment. © 2010 Elsevier Ltd. All rights reserved.

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