Localized surface plasmon (LSPR) resonance and sensing properties of a novel nanostructure (sexfoil nanoparticle) are studied using the finite-difference time-domain method. For the sandwich sexfoil nanoparticle, ...Localized surface plasmon (LSPR) resonance and sensing properties of a novel nanostructure (sexfoil nanoparticle) are studied using the finite-difference time-domain method. For the sandwich sexfoil nanoparticle, the calculated extinction spectrum shows that with the thickness of the dielectric layer increasing, long-wavelength peaks blueshift, while short- wavelength peaks redshift. Strong near-field coupling of the upper and lower metal layers leads to electric and magnetic field resonances; as the thickness increases, the electric field resonance gradually increases, while the magnetic field resonance decreases. The obtained refractive index sensitivity and figure of merit are 332 nm/RIU and 3.91 RIU^-1, respectively. In order to obtain better sensing ability, we further research the LSPR character of monolayer Ag sexfoil nanoparticle. After a series of trials to optimize the thickness and shape, the refractive index sensitivity approximates 668 nm/RIU, and the greatest figure of merit value comes to 14.8 RIU^-1.展开更多
Atmospheric visibility impairment due to human activities is becoming increasingly significant in metropolitan 8henyang, China. In this study, hourly data of relevant factors throughout the year 2010 in Shenyang were ...Atmospheric visibility impairment due to human activities is becoming increasingly significant in metropolitan 8henyang, China. In this study, hourly data of relevant factors throughout the year 2010 in Shenyang were used to evaluate the local atmospheric extinction properties. The results show that the average coefficient of total extinction and aerosol single-scattering albedo in 2010 were 622.72 Mm^-1 and 0.87, respectively, values that are characteristic of the "municipal pollution type". Visibility is most impaired during winter and especially in January. The coefficient of total extinction exhibits a single daily cycle with a maximum at 5-6 am and a minimum at 3 pm. The mean extinction contributions of the constituents, from high to low, were particle scattering (87.49%), particle absorption, gas absorption, and gas scattering. The extinction contribution of gas molecules was little more than 4.5%, far smaller than that of particles. Scattering by particles was the main contributor to extinction, especially in the morning and around midnight.展开更多
The optical extinction characteristics of the three kinds of microalgae Nannochloropsis maritirna, Ellip- soidion sp. (277.03), and Dunaliella tertiolecta were determined using an improved transmission method, in th...The optical extinction characteristics of the three kinds of microalgae Nannochloropsis maritirna, Ellip- soidion sp. (277.03), and Dunaliella tertiolecta were determined using an improved transmission method, in the 300-1800 nm spectral range. These three microalgae are promising candidates for the production of biofuels such as bio-hydrogen and biodiesel. The improved transmission method determines the spec- tral extinction coefficient of the microalgae. This is based on the measured transmittance, and employs an optical model that takes into consideration multiple reflections and refractions at the air-glass and glass-liquid interfaces. Silicon dioxide microspheres of monodisperse size were used as a model to verify the proposed method. The optical constants of the culture medium, size distributions, and extinction cross-sections of the microalgae cells were measured and analyzed. The improved transmission method is demonstrated to yield more accurate results than the traditional method. The spectral extinction effi- ciencies of the three kinds of microalgae show significant differences in the near ultraviolet and visible spectral regions. The spectral extinction efficiencies also exhibit small differences in the longer wave- length range of 950-1800 rim, with values generally less than 1.0. The measured extinction characteristics data of the three microalgae and the presented measurement method will facilitate process modeling in ohotobioreactors for biofuel oroduction.展开更多
基金supported by the Sichuan Provincial Department of Education,China(Grant No.16ZA0047)the State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,China(Grant No.201509)+1 种基金the Large Precision Instruments Open Project Foundation of Sichuan Normal University,China(Grant Nos.DJ201557,DJ201558 and DJ201560)the State Key Laboratory of Optical Technologies on Nano Fabrication and Micro Engineering,Institute of Optics and Electronics,Chinese Academy of Sciences
文摘Localized surface plasmon (LSPR) resonance and sensing properties of a novel nanostructure (sexfoil nanoparticle) are studied using the finite-difference time-domain method. For the sandwich sexfoil nanoparticle, the calculated extinction spectrum shows that with the thickness of the dielectric layer increasing, long-wavelength peaks blueshift, while short- wavelength peaks redshift. Strong near-field coupling of the upper and lower metal layers leads to electric and magnetic field resonances; as the thickness increases, the electric field resonance gradually increases, while the magnetic field resonance decreases. The obtained refractive index sensitivity and figure of merit are 332 nm/RIU and 3.91 RIU^-1, respectively. In order to obtain better sensing ability, we further research the LSPR character of monolayer Ag sexfoil nanoparticle. After a series of trials to optimize the thickness and shape, the refractive index sensitivity approximates 668 nm/RIU, and the greatest figure of merit value comes to 14.8 RIU^-1.
基金financially supported by the Basic Research and Service Fund Item of IAE(No.2013IAE-CMA05)the Integration and Application Item of Meteorological Key Technologies(No. CMAGJ2014M12)+3 种基金the National Science and Technology Pillar Program(No.2014BAC16B04)the Liaoning Province Key Technologies Program of China(No.2013229031)the Public Welfare Professional Item(Meteorology)(Nos.GYHY201406031 and 201206002)National Natural Science Foundation of China(Nos.40705037, 41375146,and 31270480)
文摘Atmospheric visibility impairment due to human activities is becoming increasingly significant in metropolitan 8henyang, China. In this study, hourly data of relevant factors throughout the year 2010 in Shenyang were used to evaluate the local atmospheric extinction properties. The results show that the average coefficient of total extinction and aerosol single-scattering albedo in 2010 were 622.72 Mm^-1 and 0.87, respectively, values that are characteristic of the "municipal pollution type". Visibility is most impaired during winter and especially in January. The coefficient of total extinction exhibits a single daily cycle with a maximum at 5-6 am and a minimum at 3 pm. The mean extinction contributions of the constituents, from high to low, were particle scattering (87.49%), particle absorption, gas absorption, and gas scattering. The extinction contribution of gas molecules was little more than 4.5%, far smaller than that of particles. Scattering by particles was the main contributor to extinction, especially in the morning and around midnight.
文摘The optical extinction characteristics of the three kinds of microalgae Nannochloropsis maritirna, Ellip- soidion sp. (277.03), and Dunaliella tertiolecta were determined using an improved transmission method, in the 300-1800 nm spectral range. These three microalgae are promising candidates for the production of biofuels such as bio-hydrogen and biodiesel. The improved transmission method determines the spec- tral extinction coefficient of the microalgae. This is based on the measured transmittance, and employs an optical model that takes into consideration multiple reflections and refractions at the air-glass and glass-liquid interfaces. Silicon dioxide microspheres of monodisperse size were used as a model to verify the proposed method. The optical constants of the culture medium, size distributions, and extinction cross-sections of the microalgae cells were measured and analyzed. The improved transmission method is demonstrated to yield more accurate results than the traditional method. The spectral extinction effi- ciencies of the three kinds of microalgae show significant differences in the near ultraviolet and visible spectral regions. The spectral extinction efficiencies also exhibit small differences in the longer wave- length range of 950-1800 rim, with values generally less than 1.0. The measured extinction characteristics data of the three microalgae and the presented measurement method will facilitate process modeling in ohotobioreactors for biofuel oroduction.