High Concentration Silver/Organic or Silver/Inorganic Nanocomposites and Their Optical Properties

Abstract The sensitivity of the interannual variations of the summer monsoons to imposed cloudiness has been studied with a general circulation model using the initial conditions prepared from the European Centre for Medium-Range Forecasts analyses of 1 May 1987 and 1988. The cloud optical properties in this global model are calculated from prognostically computed cloud liquid water. The model successfully simulates the contrasting behavior of these two successive monsoons. However, when the optical properties of the observed clouds are specified in the model runs, the simulations show some degradation over India and its vicinity. The main cause of this degradation is the reduced land–sea temperature contrast resulting from the radiative effects of the observed clouds imposed in such simulations. It is argued that the high concentration of condensed water content of clouds over the Indian land areas will serve to limit heating of the land, thereby reducing the thermal contrast that gives rise to a weak Somali jet. A countermonsoon circulation is, therefore, simulated in the vector difference field of 850-hPa winds from the model runs with externally specified clouds. This countermonsoon circulation is associated with an equatorial heat source that is the response of the model to the radiative effects of the imposed clouds. Indeed, there are at least two clear points that can be made: 1) the cloud–SST patterns, together, affect the interannual variability; and 2) with both clouds and SST imposed, the model simulation is less sensitive to initial conditions. Additionally, the study emphasizes the importance of dynamically consistent clouds developing in response to the dynamical, thermal, and moist state of the atmosphere during model integrations.

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Analysis of aerosol properties at recent (2015-2018) high PM concentration events in two super-mega cities, Seoul and Beijing

10.5194/egusphere-egu2020-20979 ◽

2020 ◽

Author(s):

Yesol Cha ◽

Chang-Keun Song

Keyword(s):

Air Pollution ◽

Optical Properties ◽

East Asian ◽

Optical Characteristics ◽

High Concentration ◽

East Asian Region ◽

Asian Region ◽

Physical Chemical ◽

Mega Cities ◽

Aerosol Properties

To meet public concerns of health caused by the high concentration of PM highly raised, this research has been done to find out unique physical, chemical, and optical characteristics of aerosols in the case of recent four years high PM concentration events over the East Asian region, especially in Korea and China. Severe air pollution over the East Asian region has occurred by the rapid development of urban areas and industrialization. Also, the meteorological conditions in East Asia are strongly correlated with a high concentration of air pollution and seasonal variation of aerosols. There are three types of aerosol properties (physical, chemical, and optical property), and each property is essential to understand the characteristics of regional and seasonal high PM concentrations. This research has been done to find out unique physical, chemical, and optical characteristics of aerosols in the case of high PM concentration events, especially in two super-mega cities (Seoul and Beijing) of Korea and China, by using various observations measured during recent four years. To analyze those characteristics of aerosols at high concentration events occur, various measurement data are used, like ambient surface air monitoring data (for physical properties) from national network in both Korea and China, Intensive Monitoring Data (for chemical properties), AERONET, GOCI satellite (for optical properties), and meteorological data during recent years (2015 &#8211; 2018). This study can provide observational evidence to confirm that each different region has different physical, chemical and optical characteristics of aerosol with the different time periods. The comprehensive results analyzed from this study and integrated methodologies suggested in this study might be useful to make a better in-depth understanding of the relations between various aerosol properties in certain regions and periods.&#160;&#160;Key words : Aerosol, High concentration events, Physical/Chemical/Optical Properties of aerosols

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Electrical and Optical Properties of Erbium in MBE Silicon and Si/Ge Alloys

MRS Proceedings ◽

10.1557/proc-220-367 ◽

1991 ◽

Vol 220 ◽

Cited By ~ 7

Author(s):

H. Efeoglu ◽

J. H. Evans ◽

J. M. Langer ◽

A. R. Peaker ◽

N. L. Rowell ◽

...

Keyword(s):

Activation Energy ◽

Optical Properties ◽

Optical Activity ◽

Electrical Measurements ◽

High Concentration ◽

Electrical And Optical Properties ◽

Shallow Donors ◽

Substrate Temperatures

ABSTRACTThis paper reports the incorporation of erbium into MBE Si and Si/Ge alloys with substrate temperatures of 500°C and 700°C. Using a solid source MBE system, concentrations of erbium between 1018 and 1022 cm−3 have been studied by photoluminescence, electrical measurements, SIMS and TEM. We find no shallow donors or acceptors attributable to erbium but we observe a high concentration of deep states with an activation energy of ∼360 meV. The photoluminescence output is of greatest magnitude when [Er] =2 × 1018 cm−3. Above this concentration the onset of erbium precipitates can just be observed using TEM and at even higher concentrations structured growths of erbium suicide are apparent. The effect on the optical activity of Si:Er that has subsequently been implanted with oxygen is also reported.

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Effect of Different Radios of Two Complexes on the Structural and Optical Properties of ZnS Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.986-987.47 ◽

2014 ◽

Vol 986-987 ◽

pp. 47-50

Author(s):

Jin Shang ◽

Huan Ke ◽

Shu Wang Duo ◽

Ting Zhi Liu ◽

Hao Zhang

Keyword(s):

Thin Films ◽

Optical Properties ◽

Visible Region ◽

Deposition Process ◽

X Ray Diffraction ◽

High Concentration ◽

Structural And Optical Properties ◽

Glass Substrates ◽

Direct Band ◽

Cbd Method

ZnS thin films were deposited at three different radios of V(NH3·H2O)/V(N2H4) on glass substrates by chemical bath deposition (CBD) method without stirring the deposition bath during the deposition process. The structural and optical properties were analyzed by X-ray diffraction (XRD) and UV-VIS spectrophotometer. The results showed that ZnS thin film deposited at the radio of V(NH3·H2O)/V(N2H4)=15:15 is higher than that of the other two different solutions. With the radio of V(NH3·H2O)/V(N2H4) decreasing from 15:5 to 15:15, homogenous precipitation of Zn (OH)2easily forms in the bath, but ZnS precipitation first become suppressed and then easily forms in solution. It means that the concentration of OH-ion increases with the volume of N2H4increasing, which accelerates the formation of Zn (OH)2. However, when the volume of N2H4increases to 15mL, relatively high concentration of OH-ion not only accelerates the formation of Zn (OH)2, but also be used to the hydrolysis of thiourea. The average transmissions of all the ZnS films from three different solutions (V(NH3·H2O)/V(N2H4)=15:5, 15:10 and 15:15) are greater than 90% for wavelength values in visible region. The direct band gaps range from 3.80 to 4.0eV. The ZnS film deposited for 2.5h with the radio of V(NH3·H2O)/V(N2H4)=15:15 has the cubic structure only after single deposition.

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