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Polarization shaping of Poincare´ beams by polariton oscillations

Light(Science & Applications) 2015年第1期4卷 122-128页

作者： David Colas Lorenzo Dominici Stefano Donati Anastasiia A Pervishko timothy ch liew Ivan A Shelykh Dario Ballarini Milena de Giorgi Alberto Bramati Giuseppe Gigli Elena del Valle Fabrice P Laussy Alexey V Kavokin Daniele Sanvitto Departamento de Fı´sica Teorica de la Materia Condensada and Condensed Matter Physics Center(IFIMAC) Universidad Autonoma de MadridE-28049Spain NANOTEC Istituto di Nanotecnologia-CNRVia Arnesano73100 LecceItaly Istituto Italiano di Tecnologia IIT-LecceVia Barsanti73010 LecceItaly Universita del Salento Via Arnesano73100 LecceItaly Division of Physics and Applied Physics Nanyang Technological University637371 SingaporeSingapore Science Institute University of IcelandDunhagi 3IS-107ReykjavikIceland Laboratory of Light-Matter Coupling in Nanostructures ITMO University197101 St.PetersburgRussia Laboratoire Kastler Brossel UPMC-Paris 6ENS et CNRS75005 ParisFrance Russian Quantum Center Novaya 100143025 SkolkovoMoscow RegionRussia CNR-SPIN Tor Vergataviale del Politechnico 1I-00133 RomeItaly

We propose theoretically and demonstrate experimentally the generation of light pulses whose polarization varies temporally to cover selected areas of the Poincare´sphere with both tunable swirling speed and total duration(1 ps and 10 ps,respectively,in our implementation).The effect relies on the Rabi oscillations of two polariton polarized fields excited by two counter-polarized and delayed *** superposition of the oscillating fields result in the precession of the Stokes vector of the emitted light while polariton lifetime imbalance results in its drift from a circle of controllable radius on the Poincare´sphere to a single point at long *** positioning of the initial circle and final point allows to engineer the type of polarization spanning,including a full sweeping of the Poincare´*** universality and simplicity of the scheme should allow for the deployment of time-varying full-Poincare´polarization fields in a variety of platforms,timescales,and regimes.

关键词： full Poincare beams polaritons polarization pulse shaping Rabi oscillations

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Cobalt catalysts supported on silica nanotubes for Fischer-Tropsch synthesis

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Science china chemistry 2012年第1期55卷 145-150页

作者： TANG HuoQiang liew KongYong LI JinLin Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission&Ministry of Education South-Central University for NationalitiesWuhan 430074 China Faculty of Industrial Science and Technology Universiti Malaysia PahangKuantan 26300Malaysia

Silica nanotubes(SNT) have been synthesized using carbon nanotubes(CNT) as a ***-coated carbon nanotubes(SNT-CNT) and SNT were loaded with a cobalt catalyst for use in Fischer-Tropsch synthesis(FTS).The catalysts were prepared by incipient wetness impregnation and characterized by N2 physisorption,X-ray diffraction(XRD),hydrogen temperature programmed reduction(H2-TPR) and transmission electron microscopy(TEM).FTS performance was evaluated in a fixed-bed reactor at 493 K and 1.0 ***/CNT and Co/SNT catalysts showed higher activity than Co/SNT-CNT in FTS because of the smaller cobalt particle size,higher dispersion and stronger *** results also showed that structure of the support affects the product selectivity in *** synergistic effects of cobalt particle size,catalytic activity and diffusion limitations as a consequence of its small average pore size lead to medium selectivity to C5+ hydrocarbons and ch4 over Co/*** the other hand,the Co/CNT showed higher ch4 selectivity and lower C5+ selectivity than Co/SNT,due to its smaller average pore size and cobalt particle size.

关键词： Fischer-Tropsch synthesis cobalt catalyst activity selectivity silica nanotubes

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Catalytic properties of Ru nanoparticles embedded on ordered mesoporous carbon with different pore size in Fischer-Tropsch synthesis

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Journal of Energy chemistry 2013年第4期22卷 560-566页

作者： Kun Xiong Yuhua Zhang Jinlin Li Kongyong liew Key Laboratory of Catalysis and Materials Science of the State Ethnic Af fairs Commission & Ministry of Education South-Central University for Nationalities College of chemistry and chemical Engineering Chongqing University College of chemistry Chemical Engineering and Materials ScienceSoochow University Faculty of Industrial Science and Technology Universiti Malaysia Pahang

A series of 3 wt% Ru embedded on ordered mesoporous carbon （OMC） catalysts with different pore sizes were prepared by autoreduction between ruthenium precursors and carbon sources at 1123 K. Ru nanoparticles were embedded on the carbon walls of OMC. characterization technologies including power X-ray diffraction （XRD）, nitrogen adsorption-desorption, transmission electron microscopy （TEM）, and hydrogen temperature-programmed reduction （H2-TPR） were used to scrutinize the catalysts. The catalyst activity for Fischer-Tropsch synthesis （FTS） was measured in a fixed bed reactor. It was revealed that 3 wt% Ru-OMC catalysts exhibited highly ordered mesoporous structure and large surface area. Compared with the catalysts with smaller pores, the catalysts with larger pores were inclined to form larger Ru particles. These 3 wt% Ru-OMC catalysts with different pore sizes were more stable than 3 wt% Ru/AC catalyst during the FTS reactions because Ru particles were embedded on the carbon walls, suppressing particles aggregation, movement and oxidation. The catalytic activity and C5＋ selectivity were found to increase with the increasing pore size, however, ch4 selectivity showed the opposite trend. These changes may be explained in terms of the special environment of the active Ru sites and the diffusion of products in the pores of the catalysts, suggesting that the activity and hydrocarbon selectivity are more dependent on the pore size of OMC than on the Ru particle size.

关键词： Fischer-Tropsch synthesis ordered mesoporous carbon Ru nanoparticle size pore size embedded

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SBA-15的硅烷化对钴基催化剂费-托合成性能的影响(英文)

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催化学报 2009年第11期30卷 1091-1095页

作者：闪媛媛刘光荣李金林中南民族大学催化材料科学湖北省暨国家民委-教育部共建重点实验室湖北武汉430074

以未硅烷化和硅烷化的SBA-15为载体,采用满孔浸渍法制备了钴基费-托合成催化剂,通过元素分析、N2吸附-脱附、X射线衍射、H2程序升温还原、H2程序升温脱附以及氧滴定等手段对催化剂进行了表征.催化剂的费-托合成活性测试在固定床反应器... 详细信息

以未硅烷化和硅烷化的SBA-15为载体,采用满孔浸渍法制备了钴基费-托合成催化剂,通过元素分析、N2吸附-脱附、X射线衍射、H2程序升温还原、H2程序升温脱附以及氧滴定等手段对催化剂进行了表征.催化剂的费-托合成活性测试在固定床反应器上进行.研究表明,对于SBA-15硅烷化后制备的催化剂,金属钴与载体之间的相互作用降低,氧化钴的还原度增加.随着三甲基氯硅烷用量的增加,三甲基硅基的表面覆盖度增加,钴的晶粒直径增大.硅烷化后的催化剂的高活性归因于高的还原度,而C5+选择性的增加则归因于钴晶粒直径的增大.

关键词：硅烷化 SBA-15 钴基催化剂费-托合成三甲基硅基

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