scholarly journals Synthesis, Morphology, and Optical Properties of Au/CdS Hybrid Nanocomposites Stabilized by Branched Polymer Matrices

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
V. A. Chumachenko ◽  
A. P. Naumenko ◽  
O. A. Yeshchenko ◽  
N. V. Kutsevol ◽  
I. S. Bondarchuk
Keyword(s):  
Surface Plasmons ◽  
Free Exciton ◽  
Fold Increase ◽  
Hybrid Nanocomposites ◽  
Plasmon Band ◽  
Au Nps ◽  
Gold Nps ◽  
The One ◽  
Average Size ◽  
Cds Nanocomposites

Metal/semiconductor (Au/CdS) nanocomposites were synthesized in the solution of branched D-g-PAA polymer. TEM and DLS of Au/CdS/D-g-PAA nanocomposites revealed complicated nanocomposite structure consisting of the Au nanoparticles (NPs) of 6 nm in size surrounded by small CdS NPs with size of 3 nm. These nanocomposites formed the aggregates-clusters with average size of 50–800 nm. Absorption spectra of Au/CdS nanocomposites consist of the bands of excitons in CdS NPs and surface plasmons in Au ones. The surface plasmon band of gold NPs is red shifted and broadened in Au/CdS/D-g-PAA nanocomposites comparing to the one of Au NPs in Au/D-g-PAA proving the fact of close location of CdS and Au NPs in the synthesized Au/CdS/D-g-PAA nanocomposites. The PL spectra of Au/CdS nanocomposites originate from the radiative transitions in excitons in CdS NPs. The 4-fold increase of intensity of free exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA that is due to PL enhancement by local field of surface plasmons of Au NPs. Also, the 12-fold decrease of intensity of localized exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA. Most probably, it is due to passivation of the surface of CdS NPs carried out by the Au ones.

scholarly journals Rapid formation methods of arrays of randomly distributed Au and Ag nanoparticles, their morphologies and optical characteristics

2021 ◽  
Vol 22 (4) ◽  
pp. 804-810
Author(s):  
V.M. Rubish ◽  
V.K. Kyrylenko ◽  
M.O. Durkot ◽  
L.I. Makar ◽  
M.M. Pop ◽  
...  
Keyword(s):  
Radiation Heating ◽  
Ag Nps ◽  
Rapid Radiation ◽  
Au Nps ◽  
Glass Substrates ◽  
Sers Substrates ◽  
Rapid Formation ◽  
Gold Nps ◽  
Average Size ◽  
Nanoparticle Sizes

By the method of rapid radiation heating (at a speed of 20-25 K/s) of Au and Ag films with a thickness of 4-35 nm to temperatures of 573-693 K in air and in the process of vacuum deposition of silver on heated (up to 700 K at a heating rate of 10 K/s ) glass substrates formed Au and Ag NPs arrays with nanoparticle sizes from several tens to hundreds of nanometers, the position λSPR of which is in the range of 520-597 nm for Au NPs and 424-509 nm for Ag NPs. It is established that the average size of nanoparticles depends on the thickness of gold and silver films and the annealing temperature. The results testify that glass substrates with arrays of randomly distributed gold NPs can be used as effective SERS-substrates for the investigation of Raman spectra of nanosized (50-100 nm) chalcogenide films.

Drawing with Performance Prediction

1995 ◽  
Author(s):  
Peter Schwenn ◽  
George Hazen
Keyword(s):  
Design Optimization ◽  
Performance Prediction ◽  
Fold Increase ◽  
Building Blocks ◽  
Programming Environment ◽  
Immediate Feedback ◽  
Surface Stability ◽  
Performance Constraints ◽  
And Performance ◽  
The One

We describe some advances in Performance Prediction Programs - "PPP"1 for sailing yachts2 - primarily integrating PPP analysis into drawing and providing new sculpting operations in which fairness and desired hydrostatic and on her performance determining characteristics are maintained - the shape remains a boat or a ship of the desired kind during reshaping. Our building blocks for such an integration are: a thousand-fold increase in PPP speed3, new editing tools which maintain Boatness4 , and an accessible modularization of the engineering physics of the PPP within a new programming environment which allows immediate changes by designers. Specifically, these new functions are introduced at the boundary of Drawing and the PPP: - A live knotmeter is displayed with each design variant on the drawing boar, - alongside it's antagonist - Rating. - Continuously updated hydrotatics (including the speed determining factors LSM, wetted surface, stability, prismatics, .. ) are displayed with the knotometer, with the 'positive' factors (like length) graphically opposing the 'negative' (like wetted surface.) Dimensions for PPP use are calculated automatically from the shape at hand - in particular: appendage dimensions, hydrostatics, and so forth. - Bounding limits are set for a design optimization by drawing two or more outlier yacht forms. The space in between can be explored by hand or automatically. - Local optimums of Speed against rating are provided as a 'Snap' function. This is the one dimensional version of automatic exploration for optima. - Intermediate shapes are also controlled during design optimization to maintain realism and performance constraints on type, fairness, 'look', speed producing shape measures like prismatic and displacement etc., and even handicap. - Immediate feedback is available if one chooses to exploit the new programming environment to make aero hydro model changes or extensions to the internal PPP mechanisms while drawing and exploring.

Light-directed on-chip shape transformation of a single gold nanoparticle

2020 ◽  
Vol 8 (45) ◽  
pp. 16198-16203
Author(s):  
Yinfeng Long ◽  
Shuangshuang Wang ◽  
Yunxia Wang ◽  
Yan Qiao ◽  
Tao Ding
Keyword(s):  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Surface Plasmons ◽  
Shape Transformation ◽  
Au Nps ◽  
Chip Shape ◽  
On Chip

Surface plasmons enable controllable shape transformation based on the dissolution and re-deposition of gold nanoparticles (Au NPs).

The confinement effect on the activity of Au NPs in polyol oxidation

2016 ◽  
Vol 6 (3) ◽  
pp. 598-601 ◽  
Author(s):  
Alberto Villa ◽  
Di Wang ◽  
Carine E. Chan-Thaw ◽  
Sebastiano Campisi ◽  
Gabriel M. Veith ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Carbon Nanofibers ◽  
Confinement Effect ◽  
Au Nps ◽  
The One

We demonstrate a confinement effect where gold nanoparticles trapped within N-functionalized carbon nanofibers (N-CNFs) are more active for polyol oxidation and promote selectivity towards di-acid products, whereas AuNPs trapped on the surface produce as a major by-product the one derived from C–C cleavage.

scholarly journals Chiral Separation of rac-Propylene Oxide on Penicillamine Coated Gold NPs

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1716
Author(s):  
Nisha Shukla ◽  
Zachary Blonder ◽  
Andrew J. Gellman
Keyword(s):  
Propylene Oxide ◽  
Room Temperature ◽  
Adsorption Properties ◽  
Time Dependent ◽  
Prior Work ◽  
Au Nps ◽  
The Past ◽  
Racemic Mixtures ◽  
Enantioselective Adsorption ◽  
Gold Nps

The surfaces of chemically synthesized spherical gold NPs (Au-NPs) have been modified using chiral L- or D-penicillamine (Pen) in order to impart enantioselective adsorption properties. These chiral Au-NPs have been used to demonstrate enantioselective adsorption of racemic propylene oxide (PO) from aqueous solution. In the past we have studied enantioselective adsorption of racemic PO on L- or D-cysteine (Cys)-coated Au-NPs. This prior work suggested that adsorption of PO on Cys-coated Au-NPs equilibrates within an hour. In this work, we have studied the effect of time on the enantioselective adsorption of racemic PO from solution onto chiral Pen/Au-NPs. Enantioselective adsorption of PO on chiral Pen/Au-NPs is time-dependent but reaches a steady state after ~18 h at room temperature. More importantly, L- or D-Pen/Au-NPs are shown to adsorb R- or S-PO enantiospecifically and to separate the two PO enantiomers from racemic mixtures of RS-PO.

scholarly journals Principle and Applications of the Coupling of Surface Plasmons and Excitons

2020 ◽  
Vol 10 (5) ◽  
pp. 1774
Author(s):  
Zhicong He ◽  
Fang Li ◽  
Yahui Liu ◽  
Fuqiang Yao ◽  
Litu Xu ◽  
...  
Keyword(s):  
Surface Plasmons ◽  
Quantum Information Processing ◽  
Research Work ◽  
Theoretical Principle ◽  
Ultra Low Power ◽  
Work Related ◽  
Plasmonic Structures ◽  
Integrated Optical ◽  
Integrated Optical Devices ◽  
The One

Surface plasmons have been attracting increasing attention and have been studied extensively in recent decades because of their half-light and half-material polarized properties. On the one hand, the tightly confined surface plasmonic mode may reduce the size of integrated optical devices beyond the diffraction limit; on the other hand, it provides an approach toward enhancement of the interactions between light and matter. In recent experiments, researchers have realized promising applications for surface plasmons in quantum information processing, ultra-low-power lasers, and micro-nano processing devices by using plasmonic structures, which have demonstrated their superiority over traditional optics structures. In this paper, we introduce the theoretical principle of surface plasmons and review the research work related to the interactions between plasmons and excitons. Some perspectives with regard to the future development of plasmonic coupling are also outlined.

Effect of Welding Method on Weld Defects of ADB610 Steel

2010 ◽  
Vol 97-101 ◽  
pp. 818-821
Author(s):  
Tian Hui Zhang ◽  
Wen Min Liu ◽  
Ren Ping Xu ◽  
Bin Xu
Keyword(s):  
Arc Welding ◽  
Qualitative Difference ◽  
Rank Test ◽  
Low Carbon ◽  
Shielded Metal Arc Welding ◽  
Weld Defects ◽  
Metal Arc Welding ◽  
Low Carbon Bainite ◽  
The One ◽  
Average Size

Statistical analysis was carried on weld defects of low carbon bainite ADB610 steel using shielded metal arc welding (SMAW) and mixed active-gas arc welding (MAG). By Pareto diagram analysis, although the ratio of porosity air hole using SMAW is slightly higher than the one using MAG, there is no qualitative difference in ADB610 steel weld defect types between two welding methods. And the crack occurs seldom, which indicates ADB610 steel has lower crack-sensitivity using SMAW and MAG. By histogram analysis and rank test, it can be concluded that there is distinctive difference in defect size between SMAW and MAG, and the average size using SMAW is bigger than the one using MAG. So if possible, MAG is recommended for low carbon bainite ADB610 steel.

STRUCTURAL AND OPTICAL PROPERTIES OF SINGLE CRYSTALLINE BISMUTH NANOPARTICLES IN POLYMER

2013 ◽  
Vol 22 ◽  
pp. 654-659 ◽  
Author(s):  
LUTFUL KABIR ◽  
SWAPAN K. MANDAL
Keyword(s):  
Optical Properties ◽  
Absorption Spectrum ◽  
Structural And Optical Properties ◽  
Chemical Route ◽  
Plasmon Band ◽  
Single Crystalline ◽  
Bismuth Nanoparticles ◽  
Transmission Electron ◽  
Average Size ◽  
Bi Nanoparticles

We report here the structural and optical properties of Bi nanoparticles in polymer (polypyrrole) matrix. The nanoparticles are synthesized following a wet chemical route. The X-ray diffraction data clearly shows the growth of single crystalline Bi nanoparticles within the host polymer. The microstructure of the Bi nanoparticles obtained by transmission electron microscopy (TEM) reveals clearly the formation of spherical shaped nanoparticles of average size∼27 nm with a narrow size distribution. The optical absorption spectrum exhibits a distinct peak at 278 nm which is attributed to the surface plasmon band of Bi nanoparticles. The absorption spectrum is found to be described well following Mie theory.

scholarly journals In vitro analysis of shear bond strength and adhesive remnant index of different metal brackets

2016 ◽  
Vol 21 (6) ◽  
pp. 67-73 ◽  
Author(s):  
Fernanda de Souza Henkin ◽  
Érika de Oliveira Dias de Macêdo ◽  
Karoline da Silva Santos ◽  
Marília Schwarzbach ◽  
Susana Maria Werner Samuel ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Fold Increase ◽  
Optical Microscope ◽  
General Evaluation ◽  
Adhesive Remnant Index ◽  
The One ◽  
Vitro Analysis ◽  
In Vitro Analysis

ABSTRACT Introduction: There is a great variety of orthodontic brackets in the Brazilian market, and constantly evaluating them is critical for professionals to know their properties, so as to be able to choose which product best suits their clinical practice. Objectives: To evaluate the bond strength and the adhesive remnant index (ARI) of different brands of metal brackets. Material and Methods: A total of 105 bovine incisors were used, and brackets of different brands were bonded to teeth. Seven different bracket brands were tested (MorelliTM, American OrthodonticsTM, TP OrthodonticsTM, Abzil-3MTM, OrthometricTM, TecnidentTM and UNIDENTM). Twenty-four hours after bonding, shear bond strength test was performed; and after debonding, the ARI was determined by using an optical microscope at a 10-fold increase. Results: Mean shear bond strength values ranged from 3.845 ± 3.997 (MorelliTM) to 9.871 ± 5.106 MPa (TecnidentTM). The majority of the ARI index scores was 0 and 1. Conclusion: Among the evaluated brackets, the one with the lowest mean shear bond strength values was MorelliTM. General evaluation of groups indicated that a greater number of bond failure occurred at the enamel/adhesive interface.

High Saturation Magnetization Fe-Co-N Thin Film Deposited by Facing-Target Direct Current Magnetron Sputtering

2011 ◽  
Vol 415-417 ◽  
pp. 1949-1952
Author(s):  
Kai Yu Yang ◽  
Yin Han Gao ◽  
Cui Mei Zhao ◽  
Xin Wang ◽  
Wei Tao Zheng
Keyword(s):  
Thin Film ◽  
Signal Processing ◽  
Magnetron Sputtering ◽  
Saturation Magnetization ◽  
High Frequency ◽  
Microwave Range ◽  
High Frequency Signal ◽  
The One ◽  
Ferromagnetic Resonance Frequency ◽  
Average Size

Magnetic materials have long been used for signal processing structures in the microwave range. High-frequency signal processing as for band-stop or notch filters, ferromagnetic resonance frequency can be adjusted or set by magnetic properties, such as saturation magnetization Ms. In this work, Fe-Co-N thin films have been synthesized using an improved facing-target magnetron sputtering system, where the sputtering current on Co and Fe targets can be regulated independently. During deposition of Fe-Co-N thin film, parameters on Fe target followed the one for synthesis of ε-Fe3N, while changing the input current on Co target. It was found that on an unheated substrate, with the Co content of about 7 at.%, high value of Ms(265.08Am2kg-1) could be obtained in the Fe-Co-N film, which contained α"-(Fe,Co)16N2nanoparticles with the average size of 7 nm.

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