scholarly journals Size Controlled CaF2Nanocubes and Their Dosimetric Properties Using Photoluminescence Technique

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Najlaa D. Alharbi
Keyword(s):  
Emission Spectrum ◽  
Uv Irradiation ◽  
Nanocrystalline Powder ◽  
Strong Emission ◽  
Strong Emission Band ◽  
Highly Sensitive ◽  
Pl Emission ◽  
Coprecipitation Route ◽  
20 Nm ◽  
Size Controlled

A new synthetic chemical coprecipitation route for the preparation of well-crystallized size controlled nano- and microcrystalline cubes of CaF2is reported. Crystalline cubes in the range of 2 μm–20 nm could be synthesized and their sizes were controlled by varying the solvent : cosolvent ratio. The as-synthesized CaF2nanocubes were characterized by different techniques. Photoluminescence (PL) emission spectrum of CaF2nanocrystalline powder showed strong emission band at 415 nm. Moreover, the effect of Eu as a dopant on the emission spectrum of CaF2was investigated. This dopant was found to get incorporated in its Eu2+and Eu3+forms. The as-produced nanocubes were exposed to UV irradiation and the corresponding PL emission was studied. Excellent results are obtained, where CaF2:Eu nanocubes were found to be highly sensitive and might be suitable for esteeming the doses of UV irradiation using the PL technique.

scholarly journals Facile synthesis of size-controlled Fe2O3 nanoparticle-decorated carbon nanotubes for highly sensitive H2S detection

RSC Advances ◽  
2018 ◽  
Vol 8 (56) ◽  
pp. 31874-31880 ◽  
Author(s):  
Wooyoung Kim ◽  
Jun Seop Lee ◽  
Jyongsik Jang
Keyword(s):  
Heat Treatment ◽  
Carbon Nanotubes ◽  
Electrode Materials ◽  
Chemical Sensor ◽  
Facile Synthesis ◽  
System P ◽  
Highly Sensitive ◽  
Fe2o3 Nanoparticle ◽  
Size Controlled ◽  
H2s Detection

Fe2O3 uniformly dispersed on carbon nanotubes are synthesized using facile oxidative co-polymerization of monomers followed by heat treatment to apply electrode materials for a highly sensitive H2S chemical sensor system.

Size controlled synthesis of CsPbBr3 QDs by two-phase emulsion extraction

2019 ◽  
Vol 12 (02) ◽  
pp. 1950012 ◽  
Author(s):  
Fan Li ◽  
Liang Luo ◽  
Maomao Wang ◽  
Yan Peng ◽  
Xiaoxia Wu ◽  
...  
Keyword(s):  
Extraction Method ◽  
Controlled Synthesis ◽  
Full Width ◽  
Half Maximum ◽  
Broad Absorption ◽  
Two Phase ◽  
Application Potential ◽  
Pl Emission ◽  
Phase Water ◽  
Size Controlled

All-inorganic perovskite CsPbBr3 QDs were prepared by two-phase (water and toluene) emulsion extraction method. By tuning the concentration of ligand, the size of QDs could be easily controlled in the range of 1–4.7[Formula: see text]nm. The prepared CsPbBr3 QDs exhibited a broad absorption range from 325 to 500[Formula: see text]nm, and a narrow full width at half maximum (FWHM) of photoluminescence (PL) emission down to 15[Formula: see text]nm. A quantum efficiency of about 69% and a PL lifetime of 40.85[Formula: see text]ns were achieved at the optimized condition, demonstrating the great application potential in optoelectronics and energy storage.

scholarly journals Calmodulin Mediates Ca2+-dependent Modulation of M-type K+ Channels

2003 ◽  
Vol 122 (1) ◽  
pp. 17-31 ◽  
Author(s):  
Nikita Gamper ◽  
Mark S. Shapiro
Keyword(s):  
Cho Cells ◽  
Dominant Negative ◽  
Wild Type ◽  
M Current ◽  
Type K ◽  
Highly Sensitive ◽  
Cell Recording ◽  
Cervical Ganglion ◽  
Tonic Current ◽  
20 Nm

To quantify the modulation of KCNQ2/3 current by [Ca2+]i and to test if calmodulin (CaM) mediates this action, simultaneous whole-cell recording and Ca2+ imaging was performed on CHO cells expressing KCNQ2/3 channels, either alone, or together with wild-type (wt) CaM, or dominant-negative (DN) CaM. We varied [Ca2+]i from <10 to >400 nM with ionomycin (5 μM) added to either a 2 mM Ca2+, or EGTA-buffered Ca2+-free, solution. Coexpression of wt CaM made KCNQ2/3 currents highly sensitive to [Ca2+]i (IC50 70 ± 20 nM, max inhibition 73%, n = 10). However, coexpression of DN CaM rendered KCNQ2/3 currents largely [Ca2+]i insensitive (max inhibition 8 ± 3%, n = 10). In cells without cotransfected CaM, the Ca2+ sensitivity was variable but generally weak. [Ca2+]i modulation of M current in superior cervical ganglion (SCG) neurons followed the same pattern as in CHO cells expressed with KCNQ2/3 and wt CaM, suggesting that endogenous M current is also highly sensitive to [Ca2+]i. Coimmunoprecipitations showed binding of CaM to KCNQ2–5 that was similar in the presence of 5 mM Ca2+ or 5 mM EGTA. Gel-shift analyses suggested Ca2+-dependent CaM binding to an “IQ-like” motif present in the carboxy terminus of KCNQ2–5. We tested whether bradykinin modulation of M current in SCG neurons uses CaM. Wt or DN CaM was exogenously expressed in SCG cells using pseudovirions or the biolistic “gene gun.” Using both methods, expression of both wt CaM and DN CaM strongly reduced bradykinin inhibition of M current, but for all groups muscarinic inhibition was unaffected. Cells expressed with wt CaM had strongly reduced tonic current amplitudes as well. We observed similar [Ca2+]i rises by bradykinin in all the groups of cells, indicating that CaM did not affect Ca2+ release from stores. We conclude that M-type currents are highly sensitive to [Ca2+]i and that calmodulin acts as their Ca2+ sensor.

Study on the Luminescence and Reflection Spectra of Al2O3 Doped Er2O3 Films on Si Substrates

2011 ◽  
Vol 474-476 ◽  
pp. 345-348
Author(s):  
Yan Yan Zhu ◽  
Ze Bo Fang ◽  
Yu Zhao ◽  
Hui Yu Li ◽  
Jing Chen ◽  
...  
Keyword(s):  
Refractive Index ◽  
Magnetron Sputtering ◽  
Emission Band ◽  
Emission Spectra ◽  
Reflection Spectra ◽  
Radio Frequency Magnetron Sputtering ◽  
Strong Emission ◽  
Si Substrates ◽  
Si Solar Cells ◽  
Strong Emission Band

Amorphous Al2O3 doped Er2O3 films were deposited on Si(001) substrates by radio frequency magnetron sputtering technique. Emission spectra exhibit a strong emission band around 410 nm and a series of emission band near 970, 980, 1018, 1042 and 1080nm. Ellipsometry measurements show that the refractive indexof the ErAlO films in the region of 400～1000 nm is between 1.76-1.83. The reflectivity of the ErAlO on Si is much smaller than that of clean Si and pure Er2O3 films. All the results indicate that ErAlO could be a promising material for Si solar cells.

A SIMPLE XUV SOURCE AT 13.5 NM BASED ON ABLATIVE CAPILLARY DISCHARGE

2002 ◽  
Vol 09 (01) ◽  
pp. 627-630 ◽  
Author(s):  
ŽELJKO ANDREIĆ ◽  
SAMIR SHAKIR ELLWI ◽  
SANDA PLESLIĆ ◽  
HANS-JOACHIM KUNZE
Keyword(s):  
Polyvinyl Chloride ◽  
Spectral Region ◽  
Emission Band ◽  
Noble Gases ◽  
Region Of Interest ◽  
Radiation Energy ◽  
Capillary Discharge ◽  
Strong Emission ◽  
Strong Emission Band

A XUV source that produces a strong emission band at the wavelength of 13.5 nm with a FWHM of 0.6 nm and a duration of about 100 ns is described. In particular this wavelength has attracted the attention of many scientists working in the field by being a good candidate for the development of XUV lithography. The source was generated by using an ablative capillary discharge where the capillary was made of PVC (polyvinyl chloride). A remarkable burst of radiation at the above wavelength was recorded, the intensity of the radiation being higher by a factor of 10 in the spectral region of interest, as compared to usually used capillaries made of POM (polyacetal), or to recently developed capillary discharges in noble gases. Total XUV radiation energy of up to 50 mJ per pulse seems to be possible with such a device. Due to its simplicity, the described capillary discharge is a good candidate for a simple incoherent XUV source at 13.5 nm.

Synthesis of Polythiophene Nanoparticles by Microemulsion Polymerization for Photocatalysis

2011 ◽  
Vol 399-401 ◽  
pp. 1312-1319 ◽  
Author(s):  
Yang Cheng ◽  
Jun Wang ◽  
Yun Cheng Bao ◽  
Ya Li Ma ◽  
Guang Hui Wang
Keyword(s):  
Methyl Orange ◽  
Surface Area ◽  
Uv Irradiation ◽  
Conjugated Polymer ◽  
Organic Dyes ◽  
Orange Ii ◽  
Microemulsion Polymerization ◽  
Before And After ◽  
Photocatalytic Reactions ◽  
20 Nm

Abstract. Polythiophene nanoparticles prepared by W/O microemulsion method were found to be photocatalytically active for degradation of Orange II dye and methyl Orange. During the photodegradation of Orange II and Methyl Orange as organic dyes in UV/H2O2and UV irradiation systems using polythiophene nanoparticles as photocatalyst, it is exhibiting significant photocatalytic activity towards to double dyes in UV and UV/H2O2system. the diameter of spherical polymer nanoparticles is 100±20 nm which was characterized by TEM with good dispersity. Furthermore, its photocatalytic efficiency for degradation of Orange II and Methyl Orange under UV irradiation is 2.54 and 1.95 times higher than normal polythiophene composites relatively. According to the testment by Accelerated Surface Area and Porosimetry System, The true cause lay in the fact that the specific surface area of Polythiophene nanoparticles is 106.6 m2/g compared to normal Polythiophene is 24.2 m2/g, This conjugated polymer characterized by FTIR spectroscopies before and after photocatalytic reactions shows reliable chemical stability. In addition, it held excellent recovery ability and kept up their catalytic activity with indistinctive drop after six repeated utilization.

scholarly journals Rapidly fabricating large-scale plasmonic silver nanosphere arrays with sub-20 nm gap on Si-pyramids by inverted annealing for highly sensitive SERS detection

RSC Advances ◽  
2017 ◽  
Vol 7 (19) ◽  
pp. 11578-11584 ◽  
Author(s):  
Yujin Wang ◽  
Yang Yang ◽  
Yu Sun ◽  
Baogang Quan ◽  
Yunlong Li ◽  
...  
Keyword(s):  
Large Scale ◽  
Highly Sensitive ◽  
Sers Detection ◽  
20 Nm ◽  
Annealing Method

An inverted annealing method is developed to fabricate rapidly plasmonic silver nanosphere arrays with sub-20 nm gaps for highly sensitive SERS detection.

High resolution emission spectrum of H2 between 78 and 118 nm

1984 ◽  
Vol 62 (12) ◽  
pp. 1686-1705 ◽  
Author(s):  
Jean-Yves Roncin ◽  
Françoise Launay ◽  
Michel Larzilliere
Keyword(s):  
High Resolution ◽  
Emission Spectrum ◽  
Appreciable Amount ◽  
Molecular Constants ◽  
Strong Emission ◽  
Reported Data ◽  
Quantum Defect Theory ◽  
First Time ◽  
Line Positions ◽  
Absorption Features

The complete high resolution emission spectrum of molecular hydrogen is obtained for the first time in the range 78–118 nm. A uniform set of data is derived from accurate line positions of the (unperturbed) Q branches of the C, D, D′, and [Formula: see text] transitions. Molecular constants fitted for both the ground state and the excited states of symmetry [Formula: see text] are obtained. For the latter case, they are compared with ab initio and multichannel quantum defect theory (MQDT) calculations. Self-absorption features indicate the production, in an appreciable amount, of H2(ν″ = 1) in the discharge. The reported data were not available to laser physicists and also astrophysicists who have observed strong emission lines of H2 from the atmospheres of Jupiter and Saturn.

Sign in / Sign up

Export Citation Format

Share Document