Thermal luminescence quenching of amine-functionalized silicon quantum dots: a pH and wavelength-dependent study

2015 ◽  
Vol 17 (37) ◽  
pp. 24078-24085 ◽  
Author(s):  
Surajit Chatterjee ◽  
Tushar Kanti Mukherjee
Keyword(s):  
Quantum Dots ◽  
Luminescence Quenching ◽  
Excitation Wavelength ◽  
Silicon Quantum Dots ◽  
Influence Of Temperature ◽  
Amine Functionalized ◽  
Influence Of Temperature On ◽  
Amine Groups

The influence of temperature on the PL properties of silicon quantum dots (Si QDs) as a function of pH and excitation wavelength has been investigated to understand the role of surface amine groups and the bandgap of allylamine-capped Si QDs.

scholarly journals Electronic States and Luminescence in Porous Silicon Quantum Dots: The Role of Oxygen

1999 ◽  
Vol 82 (1) ◽  
pp. 197-200 ◽  
Author(s):  
M. V. Wolkin ◽  
J. Jorne ◽  
P. M. Fauchet ◽  
G. Allan ◽  
C. Delerue
Keyword(s):  
Quantum Dots ◽  
Porous Silicon ◽  
Electronic States ◽  
Silicon Quantum Dots

scholarly journals Fluorescent and Mechanical Properties of Silicon Quantum Dots Modified Sodium Alginate-Carboxymethylcellulose Sodium Nanocomposite Bio-Polymer Films

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1476 ◽  
Author(s):  
Ji ◽  
Zhang ◽  
Zhang ◽  
Quan ◽  
Huang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Sodium Alginate ◽  
Polymer Films ◽  
Composite Films ◽  
Excitation Wavelength ◽  
Hydrothermal Route ◽  
Silicon Quantum Dots ◽  
One Pot ◽  
Bright Blue Fluorescence ◽  
Bright Blue

Highly luminescent silicon quantum dots (SiQDs) were prepared via one-pot hydrothermal route. Furthermore, the optimal synthetic conditions, dependence of the emission spectrum on the excitation wavelength and fluorescent stability of SiQDs were investigated by fluorescence spectroscopy. SiQDs exhibited bright blue fluorescence, and photoluminescence (PL) lifetime is 10.8 ns when excited at 325 nm. The small-sized SiQDs (~3.3 nm) possessed uniform particle size, crystal lattice spacing of 0.31 nm and silicon (111), (220) crystal planes. Luminescent SiQDs/sodium alginate (SA)-carboxymethylcellulose sodium (CMC) nanocomposite bio-polymer films were successfully fabricated by incorporating SiQDs into the SA-CMC matrix. Meanwhile, SiQDs not only impart strong fluorescence to the polymer, but also make the composite films have favorable toughness.

PHYSIOLOGIC SPECIALIZATION OF OAT STEM RUST IN CANADA

1944 ◽  
Vol 22c (5) ◽  
pp. 201-216 ◽  
Author(s):  
Margaret Newton ◽  
T. Johnson
Keyword(s):  
Stem Rust ◽  
Wide Distribution ◽  
Puccinia Graminis ◽  
Characteristic Type ◽  
Influence Of Temperature ◽  
Physiologic Specialization ◽  
Influence Of Temperature On ◽  
Physiologic Races

An account is given of the results of studies on the physiologic specialization of Puccinia graminis Avenae Erikss. and Henn. in Canada since the inception of the work. Twelve physiologic races were identified from 2586 isolates studied during the period 1921 to 1943. The annual surveys of the prevalence of physiologic races during this period show that each year races 1, 2, and 5 have comprised the bulk of the oat stem rust in all parts of Canada. The predominance of these races has been greatest in the three Prairie Provinces, where barberry is virtually non-existent. In regions where barberry is present, other races of greater range of pathogenicity have been found more frequently than in these three provinces. The occurrence of such races, however, was sporadic until 1943, in which year races 8, 10, and 11 attained a wide distribution, apparently traceable to wind-borne urediospores from the south. There is evidence that the strains of these races present in 1943 remain in the uredial stage for much longer periods than do strains of the same races collected in previous years—a fact that may have favoured their spread in this year.The role of barberry in the origination of generally virulent physiologic races is discussed. The possibility that such races may also originate by mutation is suggested by spontaneous pathogenic changes that occurred, in the greenhouse, in a culture of race 3 that gave rise to several cultures of race 7.The effect of environment on the identification of physiologic races is demonstrated by the seasonal influences on the reaction of the variety Sevnothree to races 1 and 11. On this variety the characteristic type 1 is frequently replaced, in summer, by type x.Experiments on the influence of temperature on the reaction of adult oat plants to stem rust showed that a constant temperature of about 80° F. does not appreciably affect the reaction of White Tartar and Richland, or of other varieties with the same type of resistance, but is capable of breaking down the resistance of certain varieties derived from the crosses Hajira × Joanette, Hajira × Banner, and Victoria × (Hajira × Banner).

scholarly journals Factors Affecting Concentrations of Airborne Conidia of Oidium sp. Among Poinsettias in a Greenhouse

Plant Disease ◽  
2000 ◽  
Vol 84 (10) ◽  
pp. 1089-1095 ◽  
Author(s):  
J. M. Byrne ◽  
M. K. Hausbeck ◽  
B. D. Shaw
Keyword(s):  
Relative Humidity ◽  
Rapid Decrease ◽  
Disease Development ◽  
Factors Affecting ◽  
Influence Of Temperature ◽  
Large Numbers ◽  
Airborne Conidia ◽  
Influence Of Temperature On ◽  
Atmospheric Concentrations

Atmospheric concentrations of Oidium sp. conidia in two research greenhouses containing infected poinsettias were monitored to investigate the role of environment in prompting conidial release and dissemination. Hourly concentrations of conidia of Oidium sp. were estimated using a Burkard volumetric spore sampler. The influence of temperature on disease development was studied by placing healthy poinsettias in each greenhouse for 7-day periods, removing them, and recording the days to the appearance of the first colony. When averaged over 5 December to 1 June, atmospheric conidial concentrations in greenhouse (GH) 2 were greatest during 1000 to 1800 hours with a peak (325 conidia/m3/h) occurring at 1200 hours. In GH 11, peak concentrations occurred at 1300 hours (65 conidia/m3/h) and 1600 hours (75 conidia/m3/h). Large numbers of conidia were sampled (≥100/m3) within 1-h periods, indicating conidial release events (CREs). Fluctuations in relative humidity (RH) (either positive or negative) prompted CREs. In both greenhouses, the highest number of CREs (up to 23) occurred following RH fluctuations of 5 to 15%. Watering resulted in an immediate increase (≤25%) followed by a rapid decrease in RH (≤32%) beginning 1 to 2 h later. In GH 2 and GH 11, 89 and 48%, respectively, of the CREs occurred within 3 h following greenhouse watering. When greenhouse temperatures exceeded 25°C for 21 days in May (GH 2) and 19 days in March (GH 11), atmospheric conidial concentrations were reduced 80 and 75% from the previous months, respectively.

Role of the substrate on the growth of silicon quantum dots embedded in silicon nitride thin films

2018 ◽  
Vol 208 ◽  
pp. 61-67 ◽  
Author(s):  
A. Rodríguez-Gómez ◽  
M. Moreno-Rios ◽  
R. García-García ◽  
A.L. Pérez-Martínez ◽  
J. Reyes-Gasga
Keyword(s):  
Thin Films ◽  
Quantum Dots ◽  
Silicon Nitride ◽  
Silicon Quantum Dots

Influence of temperature on sorption of europium onto smectite: The role of organic contaminants

2005 ◽  
Vol 30 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. Bauer ◽  
T. Rabung ◽  
F. Claret ◽  
T. Schäfer ◽  
G. Buckau ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Influence Of Temperature ◽  
Influence Of Temperature On
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